/* Amalgamated source file */
#include "ruby-upb.h"

/*
 * This is where we define internal portability macros used across upb.
 *
 * All of these macros are undef'd in undef.inc to avoid leaking them to users.
 *
 * The correct usage is:
 *
 *   #include "upb/foobar.h"
 *   #include "upb/baz.h"
 *
 *   // MUST be last included header.
 *   #include "upb/port/def.inc"
 *
 *   // Code for this file.
 *   // <...>
 *
 *   // Can be omitted for .c files, required for .h.
 *   #include "upb/port/undef.inc"
 *
 * This file is private and must not be included by users!
 */

#if !((defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L) || \
      (defined(__cplusplus) && __cplusplus >= 201703L) ||           \
      (defined(_MSC_VER) && _MSC_VER >= 1900))
#error upb requires C99 or C++17 or MSVC >= 2015.
#endif

// Portable check for GCC minimum version:
// https://gcc.gnu.org/onlinedocs/cpp/Common-Predefined-Macros.html
#if defined(__GNUC__) && defined(__GNUC_MINOR__) && defined(__GNUC_PATCHLEVEL__)
#define UPB_GNUC_MIN(x, y) \
  (__GNUC__ > (x) || __GNUC__ == (x) && __GNUC_MINOR__ >= (y))
#else
#define UPB_GNUC_MIN(x, y) 0
#endif

// Macros for checking for compiler attributes, defined here to avoid the
// problem described in
// https://gcc.gnu.org/onlinedocs/cpp/_005f_005fhas_005fattribute.html.
#ifdef __has_attribute
#define UPB_HAS_ATTRIBUTE(x) __has_attribute(x)
#else
#define UPB_HAS_ATTRIBUTE(x) 0
#endif

#if defined(__cplusplus) && defined(__has_cpp_attribute)
// NOTE: requiring __cplusplus above should not be necessary, but
// works around https://bugs.llvm.org/show_bug.cgi?id=23435.
#define UPB_HAS_CPP_ATTRIBUTE(x) __has_cpp_attribute(x)
#else
#define UPB_HAS_CPP_ATTRIBUTE(x) 0
#endif

// Once in a while we want to use this macro in a C++-only portion of an
// otherwise C-compatible header, so we copy and paste this from ABSL.
#if UPB_HAS_CPP_ATTRIBUTE(deprecated) && UPB_HAS_CPP_ATTRIBUTE(clang::annotate)
#define UPB_DEPRECATE_AND_INLINE() [[deprecated, clang::annotate("inline-me")]]
#elif UPB_HAS_CPP_ATTRIBUTE(deprecated)
#define UPB_DEPRECATE_AND_INLINE() [[deprecated]]
#else
#define UPB_DEPRECATE_AND_INLINE()
#endif

#ifdef __has_builtin
#define UPB_HAS_BUILTIN(x) __has_builtin(x)
#else
#define UPB_HAS_BUILTIN(x) 0
#endif

#ifdef __has_extension
#define UPB_HAS_EXTENSION(x) __has_extension(x)
#else
#define UPB_HAS_EXTENSION(x) 0
#endif

#ifdef __has_feature
#define UPB_HAS_FEATURE(x) __has_feature(x)
#else
#define UPB_HAS_FEATURE(x) 0
#endif

#include <assert.h>
#include <setjmp.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>

#ifndef UINTPTR_MAX
Error, UINTPTR_MAX is undefined
#endif

#if UINTPTR_MAX == 0xffffffff
#define UPB_SIZE(size32, size64) size32
#else
#define UPB_SIZE(size32, size64) size64
#endif

/* If we always read/write as a consistent type to each address, this shouldn't
 * violate aliasing.
 */
#define UPB_PTR_AT(msg, ofs, type) ((type*)((char*)(msg) + (ofs)))

// A flexible array member may have lower alignment requirements than the struct
// overall - in that case, it can overlap with the trailing padding of the rest
// of the struct, and a naive sizeof(base) + sizeof(flex) * count calculation
// will not take into account that overlap, and allocate more than is required.
#define UPB_SIZEOF_FLEX(type, member, count) \
  UPB_MAX(sizeof(type), offsetof(type, member[count]))

#define UPB_SIZEOF_FLEX_WOULD_OVERFLOW(type, member, count) \
  (((SIZE_MAX - offsetof(type, member[0])) /                \
    (offsetof(type, member[1]) - offsetof(type, member[0]))) < (size_t)count)

#define UPB_ARRAY_SIZE(arr) (sizeof(arr) / sizeof(arr[0]))

#define UPB_MAPTYPE_STRING 0

// UPB_EXPORT: always generate a public symbol.
#if defined(__GNUC__) || defined(__clang__)
#define UPB_EXPORT __attribute__((visibility("default"))) __attribute__((used))
#else
#define UPB_EXPORT
#endif

// UPB_INLINE: inline if possible, emit standalone code if required.
#ifdef __cplusplus
#define UPB_INLINE inline
#elif defined(__GNUC__) || defined(__clang__)
#define UPB_INLINE static __inline__
#else
#define UPB_INLINE static
#endif

// UPB_INLINE_IF_NOT_GCC: because gcc can be very noisy at times.
#if defined(__GNUC__) && !defined(__clang__)
#define UPB_INLINE_IF_NOT_GCC static
#else
#define UPB_INLINE_IF_NOT_GCC UPB_INLINE
#endif

#ifdef UPB_BUILD_API
#define UPB_API UPB_EXPORT
#define UPB_API_INLINE UPB_EXPORT
#else
#define UPB_API
#define UPB_API_INLINE UPB_INLINE
#endif

#ifdef EXPORT_UPBC
#define UPBC_API UPB_EXPORT
#else
#define UPBC_API
#endif

#if UPB_HAS_FEATURE(address_sanitizer) || defined(__SANITIZE_ADDRESS__)
#define UPB_ASAN 1
#else
#define UPB_ASAN 0
#endif

#if UPB_HAS_FEATURE(hwaddress_sanitizer)
#define UPB_HWASAN 1
#define UPB_HWASAN_POISON_TAG 17
#define UPB_MALLOC_ALIGN 16
#else
#define UPB_HWASAN 0
#define UPB_MALLOC_ALIGN 8
#endif

#if UPB_HAS_FEATURE(thread_sanitizer) || defined(__SANITIZE_THREAD__)
#define UPB_TSAN 1
#else
#define UPB_TSAN 0
#endif

#if UPB_HAS_FEATURE(memory_sanitizer)
#define UPB_MSAN 1
#else
#define UPB_MSAN 0
#endif

// An unfortunate concession to C++17 and MSVC, which don't support zero-sized
// structs.
#if UPB_ASAN || UPB_HWASAN || UPB_TSAN
#define UPB_XSAN_MEMBER upb_Xsan xsan;
#define UPB_XSAN(st) (&(st)->xsan)
#define UPB_XSAN_STRUCT_SIZE 1
#else
#define UPB_XSAN_MEMBER
#define UPB_XSAN(st) (NULL)
#define UPB_XSAN_STRUCT_SIZE 0
#endif

#define UPB_ALIGN_UP(size, align) (((size) + (align) - 1) / (align) * (align))
#define UPB_ALIGN_DOWN(size, align) ((size) / (align) * (align))
#define UPB_ALIGN_MALLOC(size) UPB_ALIGN_UP(size, UPB_MALLOC_ALIGN)

#if __STDC_VERSION__ >= 202311L || UPB_HAS_EXTENSION(cxx_alignof) || \
    defined(__cplusplus)
#define UPB_ALIGN_OF(type) alignof(type)
#elif __STDC_VERSION__ >= 201112L || UPB_HAS_EXTENSION(c_alignof)
#define UPB_ALIGN_OF(type) _Alignof(type)
#elif UPB_GNUC_MIN(2, 95)
#define UPB_ALIGN_OF(type) __alignof__(type)
#elif defined(_MSC_VER)
#define UPB_ALIGN_OF(type) __alignof(type)
#else
#define UPB_ALIGN_OF(type) \
  offsetof(                \
      struct {             \
        char c;            \
        type member;       \
      },                   \
      member)
#endif

#ifdef _MSC_VER
// Some versions of our Windows compiler don't support the C11 syntax.
#define UPB_ALIGN_AS(x) __declspec(align(x))
#elif defined(__GNUC__)
#define UPB_ALIGN_AS(x) __attribute__((aligned(x)))
#else
#define UPB_ALIGN_AS(x) _Alignas(x)
#endif

#if __STDC_VERSION__ >= 202311L || UPB_HAS_EXTENSION(cxx_static_assert) || \
    defined(__cplusplus)
#define UPB_STATIC_ASSERT(val, msg) static_assert((val), msg)
#elif __STDC_VERSION__ >= 201112L || UPB_HAS_EXTENSION(c_static_assert) || \
    UPB_GNUC_MIN(4, 6)
#define UPB_STATIC_ASSERT(val, msg) _Static_assert((val), msg)
#else
// Unfortunately this hack doesn't work inside struct declarations, but it works
// everywhere else
#define UPB_STATIC_ASSERT_CONCAT_IMPL(s1, s2) s1##s2
#define UPB_STATIC_ASSERT_CONCAT(s1, s2) UPB_STATIC_ASSERT_CONCAT_IMPL(s1, s2)
#ifdef __COUNTER__
#define UPB_STATIC_ASSERT(condition, message)                      \
  typedef char UPB_STATIC_ASSERT_CONCAT(static_assertion_failure_, \
                                        __COUNTER__)[(condition) ? 1 : -1]
#else
#define UPB_STATIC_ASSERT(condition, message)                      \
  typedef char UPB_STATIC_ASSERT_CONCAT(static_assertion_failure_, \
                                        __LINE__)[(condition) ? 1 : -1]
#endif
#endif

// Hints to the compiler about likely/unlikely branches.
#if defined(__GNUC__) || defined(__clang__)
#define UPB_LIKELY(x) __builtin_expect((bool)(x), 1)
#define UPB_UNLIKELY(x) __builtin_expect((bool)(x), 0)
#else
#define UPB_LIKELY(x) (x)
#define UPB_UNLIKELY(x) (x)
#endif

#if UPB_HAS_BUILTIN(__builtin_expect_with_probability)
#define UPB_UNPREDICTABLE(x) \
  __builtin_expect_with_probability((bool)(x), 1, 0.5)
#else
#define UPB_UNPREDICTABLE(x) (x)
#endif

// Macros for function attributes on compilers that support them.
#if defined(__GNUC__) || defined(__clang__)
#define UPB_FORCEINLINE __inline__ __attribute__((always_inline)) static
#define UPB_NOINLINE __attribute__((noinline))
#define UPB_NORETURN __attribute__((__noreturn__))
#define UPB_PRINTF(str, first_vararg) \
  __attribute__((format(printf, str, first_vararg)))
#elif defined(_MSC_VER)
#define UPB_NOINLINE
#define UPB_FORCEINLINE static
#define UPB_NORETURN __declspec(noreturn)
#define UPB_PRINTF(str, first_vararg)
#else /* !defined(__GNUC__) */
#define UPB_FORCEINLINE static
#define UPB_NOINLINE
#define UPB_NORETURN
#define UPB_PRINTF(str, first_vararg)
#endif

#if defined(__clang__)
#define UPB_NODEREF __attribute__((noderef))
#else
#define UPB_NODEREF
#endif

#define UPB_MAX(x, y) ((x) > (y) ? (x) : (y))
#define UPB_MIN(x, y) ((x) < (y) ? (x) : (y))

#define UPB_UNUSED(var) (void)(var)

// UPB_ASSUME(): in release mode, we tell the compiler to assume this is true.
#ifdef NDEBUG
#ifdef __GNUC__
#define UPB_ASSUME(expr) \
  if (!(expr)) __builtin_unreachable()
#elif defined _MSC_VER
#define UPB_ASSUME(expr) \
  if (!(expr)) __assume(0)
#else
#define UPB_ASSUME(expr) \
  do {                   \
  } while (false && (expr))
#endif
#else
#define UPB_ASSUME(expr) assert(expr)
#endif

#if UPB_HAS_BUILTIN(__builtin_constant_p) && UPB_HAS_ATTRIBUTE(const)
#define UPB_MAYBE_ASSUME(pred, x) \
  if (__builtin_constant_p(pred) && pred) UPB_ASSUME(x)
#define UPB_ATTR_CONST __attribute__((const))
#else
#define UPB_MAYBE_ASSUME(pred, x)
#define UPB_ATTR_CONST
#endif

/* UPB_ASSERT(): in release mode, we use the expression without letting it be
 * evaluated.  This prevents "unused variable" warnings. */
#ifdef NDEBUG
#define UPB_ASSERT(expr) \
  do {                   \
  } while (false && (expr))
#else
#define UPB_ASSERT(expr) assert(expr)
#endif

#if !defined(NDEBUG) && !defined(UPB_TSAN)
#define UPB_ENABLE_REF_CYCLE_CHECKS 1
#else
#define UPB_ENABLE_REF_CYCLE_CHECKS 0
#endif

#if defined(__GNUC__) || defined(__clang__)
#define UPB_UNREACHABLE()    \
  do {                       \
    assert(0);               \
    __builtin_unreachable(); \
  } while (0)
#elif defined(_MSC_VER)
#define UPB_UNREACHABLE() \
  do {                    \
    assert(0);            \
    __assume(0);          \
  } while (0)
#else
#define UPB_UNREACHABLE() \
  do {                    \
    assert(0);            \
  } while (0)
#endif

#ifdef __ANDROID__
#define UPB_DEFAULT_MAX_BLOCK_SIZE 8192
#else
#define UPB_DEFAULT_MAX_BLOCK_SIZE 32768
#endif

/* UPB_SETJMP() / UPB_LONGJMP() */
// Android uses a custom libc that does not implement all of posix, but it has
// had sigsetjmp/siglongjmp forever on arm and since API 12 on x86. Apple has
// sigsetjmp, but does not define the posix feature test macro.
#if defined(__APPLE__) || defined(_POSIX_C_SOURCE) || defined(__ANDROID__)
// avoid setting/restoring signal mask, which involves costly syscalls
#define UPB_SETJMP(buf) sigsetjmp(buf, 0)
#define UPB_LONGJMP(buf, val) siglongjmp(buf, val)
#elif defined(WASM_WAMR)
#define UPB_SETJMP(buf) 0
#define UPB_LONGJMP(buf, val) abort()
#else
#define UPB_SETJMP(buf) setjmp(buf)
#define UPB_LONGJMP(buf, val) longjmp(buf, val)
#endif

#if ((__STDC_VERSION__ >= 201112L) && !defined(__STDC_NO_ATOMICS__)) || \
    UPB_HAS_EXTENSION(c_atomic) ||                                      \
    defined(__GNUC__)  // GCC supported atomics as an extension before it
                       // supported __has_extension
#define UPB_USE_C11_ATOMICS
#elif defined(_MSC_VER)
#define UPB_USE_MSC_ATOMICS
#endif

#if defined(UPB_USE_C11_ATOMICS)
#define UPB_ATOMIC(T) _Atomic(T)
#elif defined(UPB_USE_MSC_ATOMICS)
#define UPB_ATOMIC(T) volatile T
#else
#define UPB_ATOMIC(T) T
#endif

/* UPB_PTRADD(ptr, ofs): add pointer while avoiding "NULL + 0" UB */
#define UPB_PTRADD(ptr, ofs) ((ofs) ? (ptr) + (ofs) : (ptr))

#define UPB_PRIVATE(x) x##_dont_copy_me__upb_internal_use_only

#ifdef UPB_ALLOW_PRIVATE_ACCESS__FOR_BITS_ONLY
#define UPB_ONLYBITS(x) x
#else
#define UPB_ONLYBITS(x) UPB_PRIVATE(x)
#endif

/* Configure whether fasttable is switched on or not. *************************/

#if UPB_HAS_ATTRIBUTE(musttail)
#define UPB_MUSTTAIL __attribute__((musttail))
#else
#define UPB_MUSTTAIL
#endif

#if UPB_HAS_ATTRIBUTE(preserve_most) && !defined(__i386__)
#define UPB_PRESERVE_MOST __attribute__((preserve_most))
#else
#define UPB_PRESERVE_MOST
#endif

#if UPB_HAS_ATTRIBUTE(preserve_none)
#define UPB_PRESERVE_NONE __attribute__((preserve_none))
#else
#define UPB_PRESERVE_NONE
#endif

#if defined(__aarch64__) && (defined(__GNUC__) || defined(__clang__))
#define UPB_ARM64_ASM 1
#else
#define UPB_ARM64_ASM 0
#endif

/* When compiling with branch protection, we need to ensure that all branch
 * targets in assembly use the appropriate landing pad instruction. These
 * instructions are backwards compatible with processors that don't have
 * FEAT_BTI and are treated as nops.
 */
#if UPB_ARM64_ASM && defined(__ARM_FEATURE_BTI_DEFAULT)
#if __ARM_FEATURE_BTI_DEFAULT == 1
#define UPB_ARM64_BTI_DEFAULT 1
#else
#define UPB_ARM64_BTI_DEFAULT 0
#endif
#else
#define UPB_ARM64_BTI_DEFAULT 0
#endif

/* This check is not fully robust: it does not require that we have "musttail"
 * support available. We need tail calls to avoid consuming arbitrary amounts
 * of stack space.
 *
 * GCC/Clang can mostly be trusted to generate tail calls as long as
 * optimization is enabled, but, debug builds will not generate tail calls
 * unless "musttail" is available.
 *
 * We should probably either:
 *   1. require that the compiler supports musttail.
 *   2. add some fallback code for when musttail isn't available (ie. return
 *      instead of tail calling). This is safe and portable, but this comes at
 *      a CPU cost.
 */
#if (defined(__x86_64__) || defined(__aarch64__)) && defined(__GNUC__)
#define UPB_FASTTABLE_SUPPORTED 1
#else
#define UPB_FASTTABLE_SUPPORTED 0
#endif

/* define UPB_ENABLE_FASTTABLE to force fast table support.
 * This is useful when we want to ensure we are really getting fasttable,
 * for example for testing or benchmarking. */
#if defined(UPB_ENABLE_FASTTABLE)
#if !UPB_FASTTABLE_SUPPORTED
#error fasttable is x86-64/ARM64 only and requires GCC or Clang.
#endif
#define UPB_FASTTABLE 1
/* Define UPB_TRY_ENABLE_FASTTABLE to use fasttable if possible.
 * This is useful for releasing code that might be used on multiple platforms,
 * for example the PHP or Ruby C extensions. */
#elif defined(UPB_TRY_ENABLE_FASTTABLE)
#define UPB_FASTTABLE UPB_FASTTABLE_SUPPORTED
#else
#define UPB_FASTTABLE 0
#endif

/* UPB_FASTTABLE_INIT() allows protos compiled for fasttable to gracefully
 * degrade to non-fasttable if the runtime or platform do not support it. */
#if !UPB_FASTTABLE
#define UPB_FASTTABLE_INIT(...)
#define UPB_FASTTABLE_MASK(mask) -1
#else
#define UPB_FASTTABLE_INIT(...) __VA_ARGS__
#define UPB_FASTTABLE_MASK(mask) mask
#endif

#undef UPB_FASTTABLE_SUPPORTED

#if defined(__cplusplus)
#if defined(__clang__) || UPB_GNUC_MIN(6, 0)
// https://gcc.gnu.org/gcc-6/changes.html
#define UPB_DEPRECATED [[deprecated]]
#else
#define UPB_DEPRECATED
#endif
#else
#define UPB_DEPRECATED
#endif

#if defined(UPB_IS_GOOGLE3) && \
    (!defined(UPB_BOOTSTRAP_STAGE) || UPB_BOOTSTRAP_STAGE != 0)
#define UPB_DESC_MINITABLE(sym) &proto2__##sym##_msg_init
#elif defined(UPB_IS_GOOGLE3) && defined(UPB_BOOTSTRAP_STAGE) && \
    UPB_BOOTSTRAP_STAGE == 0
#define UPB_DESC_MINITABLE(sym) proto2__##sym##_msg_init()
#elif defined(UPB_BOOTSTRAP_STAGE) && UPB_BOOTSTRAP_STAGE == 0
#define UPB_DESC_MINITABLE(sym) google__protobuf__##sym##_msg_init()
#else
#define UPB_DESC_MINITABLE(sym) &google__protobuf__##sym##_msg_init
#endif

#undef UPB_IS_GOOGLE3

#ifdef __clang__
#define UPB_NO_SANITIZE_ADDRESS __attribute__((no_sanitize("address")))
#else
#define UPB_NO_SANITIZE_ADDRESS
#endif

#if defined(__GNUC__) && (defined(__clang__) || UPB_GNUC_MIN(11, 0))
#define UPB_RETAIN __attribute__((retain))
#else
#define UPB_RETAIN
#endif

// Linker arrays combine elements from multiple translation units into a single
// array that can be iterated over at runtime.
//
// It is an alternative to pre-main "registration" functions.
//
// Usage:
//
//   // In N translation units.
//   UPB_LINKARR_APPEND(foo_array) static int elems[3] = {1, 2, 3};
//
//   // At runtime:
//   UPB_LINKARR_DECLARE(foo_array, int);
//
//   void f() {
//     const int* start = UPB_LINKARR_START(foo_array);
//     const int* stop = UPB_LINKARR_STOP(foo_array);
//     for (const int* p = start; p < stop; p++) {
//       // Windows can introduce zero padding, so we have to skip zeroes.
//       if (*p != 0) {
//         vec.push_back(*p);
//       }
//     }
//   }

#if defined(__GNUC__) && !defined(__clang__)
// GCC can't handle mismatched retain attributes in the same section:
//   https://github.com/protocolbuffers/protobuf/issues/26385
// To work around this, we retain all linker array elements, even though this
// effectively disables tree-shaking of unused extensions when using GCC.
#define UPB_LINKARR_ATTR UPB_RETAIN
#else
#define UPB_LINKARR_ATTR
#endif

#define UPB_LINKARR_SENTINEL UPB_RETAIN __attribute__((weak, used))

#if defined(__ELF__) || defined(__wasm__)

#define UPB_LINKARR_APPEND(name) \
  __attribute__((                \
      section("linkarr_" #name))) UPB_LINKARR_ATTR UPB_NO_SANITIZE_ADDRESS
#define UPB_LINKARR_DECLARE(name, type) \
  extern type __start_linkarr_##name;   \
  extern type __stop_linkarr_##name;    \
  UPB_LINKARR_APPEND(name)              \
  UPB_LINKARR_SENTINEL type UPB_linkarr_internal_empty_##name[1]
#define UPB_LINKARR_START(name) (&__start_linkarr_##name)
#define UPB_LINKARR_STOP(name) (&__stop_linkarr_##name)

#elif defined(__MACH__)

/* As described in: https://stackoverflow.com/a/22366882 */
#define UPB_LINKARR_APPEND(name) \
  __attribute__((                \
      section("__DATA,__la_" #name))) UPB_LINKARR_ATTR UPB_NO_SANITIZE_ADDRESS
#define UPB_LINKARR_DECLARE(name, type)     \
  extern type __start_linkarr_##name __asm( \
      "section$start$__DATA$__la_" #name);  \
  extern type __stop_linkarr_##name __asm(  \
      "section$end$__DATA$"                 \
      "__la_" #name);                       \
  UPB_LINKARR_APPEND(name)                  \
  UPB_LINKARR_SENTINEL type UPB_linkarr_internal_empty_##name[1]
#define UPB_LINKARR_START(name) (&__start_linkarr_##name)
#define UPB_LINKARR_STOP(name) (&__stop_linkarr_##name)

#elif defined(_MSC_VER)

/* See:
 *   https://devblogs.microsoft.com/oldnewthing/20181107-00/?p=100155
 *   https://devblogs.microsoft.com/oldnewthing/20181108-00/?p=100165
 *   https://devblogs.microsoft.com/oldnewthing/20181109-00/?p=100175 */
#define UPB_STRINGIFY_INTERNAL(x) #x
#define UPB_STRINGIFY(x) UPB_STRINGIFY_INTERNAL(x)
#define UPB_CONCAT(a, b, c) a##b##c
#define UPB_LINKARR_NAME(name, index) \
  UPB_STRINGIFY(UPB_CONCAT(la_, name, index))
#define UPB_LINKARR_APPEND(name)                      \
  __pragma(section(UPB_LINKARR_NAME(name, $j), read)) \
      __declspec(allocate(UPB_LINKARR_NAME(name, $j)))
// clang-format off
#define UPB_LINKARR_DECLARE(name, type)                          \
  __pragma(message(UPB_LINKARR_NAME(name, $j)))                  \
  __pragma(section(UPB_LINKARR_NAME(name, $a), read))            \
  __pragma(section(UPB_LINKARR_NAME(name, $z), read))            \
  __declspec(allocate(UPB_LINKARR_NAME(name, $a)), selectany)    \
            type __start_linkarr_##name;                         \
  __declspec(allocate(UPB_LINKARR_NAME(name, $z)), selectany)    \
            type __stop_linkarr_##name;                          \
  UPB_LINKARR_APPEND(name)                                       \
  __declspec(selectany) type UPB_linkarr_internal_empty_##name[1] = {0}
// clang-format on
#define UPB_LINKARR_START(name) (&__start_linkarr_##name)
#define UPB_LINKARR_STOP(name) (&__stop_linkarr_##name)

#else

// Linker arrays are not supported on this platform.  Make macros no-ops.
#define UPB_LINKARR_APPEND(name)
#define UPB_LINKARR_DECLARE(name, type)
#define UPB_LINKARR_START(name) (NULL)
#define UPB_LINKARR_STOP(name) (NULL)

#endif

// Workaround for https://github.com/llvm/llvm-project/issues/167577 until it's
// fixed.  Some function must exist for the constructor to work properly.
// TODO Remove this or gate it on a future version of clang.
#if defined(__clang__) && defined(__arm__)
#define _UPB_CONSTRUCTOR_PLACEHOLDER(unique_name)                            \
  __attribute__((used, visibility("hidden"))) void UPB_PRIVATE(unique_name)( \
      void) {}
#else
#define _UPB_CONSTRUCTOR_PLACEHOLDER(unique_name)
#endif

#if defined(__ELF__) || defined(__wasm__) || defined(__MACH__)
#define UPB_CONSTRUCTOR(name, unique_name)                                   \
  _UPB_CONSTRUCTOR_PLACEHOLDER(unique_name)                                  \
  __attribute__((weak, visibility("hidden"), constructor)) void UPB_PRIVATE( \
      name)(void)
#elif defined(_MSC_VER)
/*
 * See: https://stackoverflow.com/questions/1113409
 *
 * The /include pragma suggested in the link above doesn't work in our case
 * because it requires globally unique names. We need a different solution
 * to prevent optimizers from removing the constructor. Our solution is to
 * create a dummy exported weak symbol that prevent this stripping.
 */
#pragma section(".CRT$XCT", read)
#define UPB_CONSTRUCTOR(name, unique_name)                                   \
  static void __cdecl UPB_PRIVATE(name)(void);                               \
  __declspec(allocate(".CRT$XCT"), selectany) void(                          \
      __cdecl * UPB_PRIVATE(name##_))(void) = UPB_PRIVATE(name);             \
  __declspec(selectany, dllexport) void* UPB_PRIVATE(name##_force_linkage) = \
      &UPB_PRIVATE(name##_);                                                 \
  static void __cdecl UPB_PRIVATE(name)(void)

#else
// No constructor support, nothing we can do except not break builds.
#define UPB_CONSTRUCTOR(name, unique_name) static void UPB_PRIVATE(name)(void)
#endif

//
// Weak alias platform support. Theoretically this should be possible to do with
// only C using attributes like __attribute__((weak, alias("foo"))), but
// Clang doesn't support this properly on macOS.  So we have to use assembly.
#if defined(__APPLE__)

// TODO: once https://github.com/llvm/llvm-project/issues/167262 is fixed
// in the LLVM linker, we should have all weak variables point to a single
// "default" empty MiniTable instead of having each leaf define its own, like
// we do with ELF below. This will reduce binary size if many messages are tree
// shaken.
#define UPB_WEAK_SINGLETON_PLACEHOLDER_MINITABLE()
#define UPB_WEAK_PLACEHOLDER_MINITABLE(name)           \
  __attribute__((weak)) const upb_MiniTable name = {   \
      .UPB_PRIVATE(fields) = NULL,                     \
      .UPB_PRIVATE(size) = sizeof(struct upb_Message), \
      .UPB_PRIVATE(field_count) = 0,                   \
      .UPB_PRIVATE(ext) = kUpb_ExtMode_NonExtendable,  \
      .UPB_PRIVATE(dense_below) = 0,                   \
      .UPB_PRIVATE(table_mask) = -1,                   \
      .UPB_PRIVATE(required_count) = 0,                \
  };
#define UPB_WEAK_ALIAS(type, from, to) \
  extern type to;                      \
  __asm__(".globl _" #to);             \
  __asm__(".private_extern _" #to);    \
  __asm__(".set _" #to ", _" #from);   \
  __asm__(".weak_definition _" #to);
#define UPB_STRONG_ALIAS(type, from, to) \
  __asm__(".globl _" #to);               \
  __asm__(".private_extern _" #to);      \
  __asm__(".set _" #to ", _" #from);

#elif defined(__ELF__)

// On ELF, weak aliases work properly, so we can have all weak MiniTables point
// to the same empty singleton MiniTable. This reduces code size if many
// MiniTables are tree shaken.
#define UPB_WEAK_SINGLETON_PLACEHOLDER_MINITABLE()               \
  __attribute__((weak))                                          \
  const upb_MiniTable kUpb_WeakSingletonPlaceholderMiniTable = { \
      .UPB_PRIVATE(fields) = NULL,                               \
      .UPB_PRIVATE(size) = sizeof(struct upb_Message),           \
      .UPB_PRIVATE(field_count) = 0,                             \
      .UPB_PRIVATE(ext) = kUpb_ExtMode_NonExtendable,            \
      .UPB_PRIVATE(dense_below) = 0,                             \
      .UPB_PRIVATE(table_mask) = -1,                             \
      .UPB_PRIVATE(required_count) = 0,                          \
  };
#define UPB_WEAK_PLACEHOLDER_MINITABLE(name)
#define UPB_WEAK_ALIAS(type, from, to) \
  extern type to                       \
      __attribute__((weak, alias("kUpb_WeakSingletonPlaceholderMiniTable")));
#define UPB_STRONG_ALIAS(type, from, to) \
  extern type to __attribute__((alias(#from)));

#else
#define UPB_WEAK_SINGLETON_PLACEHOLDER_MINITABLE()
#define UPB_WEAK_PLACEHOLDER_MINITABLE(name)
#define UPB_WEAK_ALIAS(type, from, to) weak_alias_not_supported_on_this_platform
#define UPB_STRONG_ALIAS(type, from, to) \
  strong_alias_not_supported_on_this_platform
#endif

// Future versions of upb will include breaking changes to some APIs.
// This macro can be set to enable these API changes ahead of time, so that
// user code can be updated before upgrading versions of protobuf.
#ifdef UPB_FUTURE_BREAKING_CHANGES

#endif

/* This file was generated by upb_generator from the input file:
 *
 *     google/protobuf/descriptor.proto
 *
 * Do not edit -- your changes will be discarded when the file is
 * regenerated.
 * NO CHECKED-IN PROTOBUF GENCODE */

#include <stddef.h>

// Must be last.

extern const UPB_PRIVATE(upb_GeneratedExtensionListEntry)* UPB_PRIVATE(upb_generated_extension_list);
typedef struct {
  upb_MiniTableField fields[1];
  upb_MiniTableSubInternal subs[1];
} google__protobuf__FileDescriptorSet_msg_init_Fields;

static const google__protobuf__FileDescriptorSet_msg_init_Fields google_protobuf_FileDescriptorSet__fields = {{
  {1, 8, 0, UPB_SIZE(3, 4), 11, (int)kUpb_FieldMode_Array | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
 },
  {
  {.UPB_PRIVATE(submsg) = &google__protobuf__FileDescriptorProto_msg_init},
}};

const upb_MiniTable google__protobuf__FileDescriptorSet_msg_init = {
  &google_protobuf_FileDescriptorSet__fields.fields[0],
  16, 1, kUpb_ExtMode_Extendable, 1, UPB_FASTTABLE_MASK(255), 0,
#ifdef UPB_TRACING_ENABLED
  "google.protobuf.FileDescriptorSet",
#endif
};

typedef struct {
  upb_MiniTableField fields[14];
  upb_MiniTableSubInternal subs[7];
} google__protobuf__FileDescriptorProto_msg_init_Fields;

static const google__protobuf__FileDescriptorProto_msg_init_Fields google_protobuf_FileDescriptorProto__fields = {{
  {1, UPB_SIZE(56, 16), 64, kUpb_NoSub, 12, (int)kUpb_FieldMode_Scalar | (int)kUpb_LabelFlags_IsAlternate | ((int)kUpb_FieldRep_StringView << kUpb_FieldRep_Shift)},
  {2, UPB_SIZE(64, 32), 65, kUpb_NoSub, 12, (int)kUpb_FieldMode_Scalar | (int)kUpb_LabelFlags_IsAlternate | ((int)kUpb_FieldRep_StringView << kUpb_FieldRep_Shift)},
  {3, UPB_SIZE(12, 64), 0, kUpb_NoSub, 12, (int)kUpb_FieldMode_Array | (int)kUpb_LabelFlags_IsAlternate | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
  {4, UPB_SIZE(16, 72), 0, 33, 11, (int)kUpb_FieldMode_Array | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
  {5, UPB_SIZE(20, 80), 0, UPB_SIZE(31, 32), 11, (int)kUpb_FieldMode_Array | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
  {6, UPB_SIZE(24, 88), 0, UPB_SIZE(29, 31), 11, (int)kUpb_FieldMode_Array | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
  {7, UPB_SIZE(28, 96), 0, UPB_SIZE(27, 30), 11, (int)kUpb_FieldMode_Array | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
  {8, UPB_SIZE(32, 104), 66, UPB_SIZE(25, 29), 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
  {9, UPB_SIZE(36, 112), 67, UPB_SIZE(23, 28), 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
  {10, UPB_SIZE(40, 120), 0, kUpb_NoSub, 5, (int)kUpb_FieldMode_Array | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
  {11, UPB_SIZE(44, 128), 0, kUpb_NoSub, 5, (int)kUpb_FieldMode_Array | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
  {12, UPB_SIZE(72, 48), 68, kUpb_NoSub, 12, (int)kUpb_FieldMode_Scalar | (int)kUpb_LabelFlags_IsAlternate | ((int)kUpb_FieldRep_StringView << kUpb_FieldRep_Shift)},
  {14, UPB_SIZE(48, 12), 69, UPB_SIZE(12, 18), 14, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_4Byte << kUpb_FieldRep_Shift)},
  {15, UPB_SIZE(52, 136), 0, kUpb_NoSub, 12, (int)kUpb_FieldMode_Array | (int)kUpb_LabelFlags_IsAlternate | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
 },
  {
  {.UPB_PRIVATE(submsg) = &google__protobuf__DescriptorProto_msg_init},
  {.UPB_PRIVATE(submsg) = &google__protobuf__EnumDescriptorProto_msg_init},
  {.UPB_PRIVATE(submsg) = &google__protobuf__ServiceDescriptorProto_msg_init},
  {.UPB_PRIVATE(submsg) = &google__protobuf__FieldDescriptorProto_msg_init},
  {.UPB_PRIVATE(submsg) = &google__protobuf__FileOptions_msg_init},
  {.UPB_PRIVATE(submsg) = &google__protobuf__SourceCodeInfo_msg_init},
  {.UPB_PRIVATE(subenum) = &google__protobuf__Edition_enum_init},
}};

const upb_MiniTable google__protobuf__FileDescriptorProto_msg_init = {
  &google_protobuf_FileDescriptorProto__fields.fields[0],
  UPB_SIZE(80, 144), 14, kUpb_ExtMode_NonExtendable, 12, UPB_FASTTABLE_MASK(120), 0,
#ifdef UPB_TRACING_ENABLED
  "google.protobuf.FileDescriptorProto",
#endif
  UPB_FASTTABLE_INIT({
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x001000000000000a, &upb_DecodeFast_Bytes_Scalar_Tag1Byte},
    {0x0020000001000012, &upb_DecodeFast_Bytes_Scalar_Tag1Byte},
    {0x004000003f00001a, &upb_DecodeFast_Bytes_Repeated_Tag1Byte},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x007800003f000050, &upb_DecodeFast_Varint32_Repeated_Tag1Byte},
    {0x008000003f000058, &upb_DecodeFast_Varint32_Repeated_Tag1Byte},
    {0x0030000004000062, &upb_DecodeFast_Bytes_Scalar_Tag1Byte},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x008800003f00007a, &upb_DecodeFast_Bytes_Repeated_Tag1Byte},
  })
};

typedef struct {
  upb_MiniTableField fields[11];
  upb_MiniTableSubInternal subs[9];
} google__protobuf__DescriptorProto_msg_init_Fields;

static const google__protobuf__DescriptorProto_msg_init_Fields google_protobuf_DescriptorProto__fields = {{
  {1, UPB_SIZE(52, 16), 64, kUpb_NoSub, 12, (int)kUpb_FieldMode_Scalar | (int)kUpb_LabelFlags_IsAlternate | ((int)kUpb_FieldRep_StringView << kUpb_FieldRep_Shift)},
  {2, UPB_SIZE(12, 32), 0, UPB_SIZE(30, 31), 11, (int)kUpb_FieldMode_Array | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
  {3, UPB_SIZE(16, 40), 0, UPB_SIZE(28, 30), 11, (int)kUpb_FieldMode_Array | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
  {4, UPB_SIZE(20, 48), 0, UPB_SIZE(26, 29), 11, (int)kUpb_FieldMode_Array | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
  {5, UPB_SIZE(24, 56), 0, UPB_SIZE(24, 28), 11, (int)kUpb_FieldMode_Array | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
  {6, UPB_SIZE(28, 64), 0, UPB_SIZE(22, 27), 11, (int)kUpb_FieldMode_Array | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
  {7, UPB_SIZE(32, 72), 65, UPB_SIZE(20, 26), 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
  {8, UPB_SIZE(36, 80), 0, UPB_SIZE(18, 25), 11, (int)kUpb_FieldMode_Array | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
  {9, UPB_SIZE(40, 88), 0, UPB_SIZE(16, 24), 11, (int)kUpb_FieldMode_Array | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
  {10, UPB_SIZE(44, 96), 0, kUpb_NoSub, 12, (int)kUpb_FieldMode_Array | (int)kUpb_LabelFlags_IsAlternate | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
  {11, UPB_SIZE(48, 12), 66, UPB_SIZE(11, 20), 14, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_4Byte << kUpb_FieldRep_Shift)},
 },
  {
  {.UPB_PRIVATE(submsg) = &google__protobuf__FieldDescriptorProto_msg_init},
  {.UPB_PRIVATE(submsg) = &google__protobuf__DescriptorProto_msg_init},
  {.UPB_PRIVATE(submsg) = &google__protobuf__EnumDescriptorProto_msg_init},
  {.UPB_PRIVATE(submsg) = &google__protobuf__DescriptorProto__ExtensionRange_msg_init},
  {.UPB_PRIVATE(submsg) = &google__protobuf__FieldDescriptorProto_msg_init},
  {.UPB_PRIVATE(submsg) = &google__protobuf__MessageOptions_msg_init},
  {.UPB_PRIVATE(submsg) = &google__protobuf__OneofDescriptorProto_msg_init},
  {.UPB_PRIVATE(submsg) = &google__protobuf__DescriptorProto__ReservedRange_msg_init},
  {.UPB_PRIVATE(subenum) = &google__protobuf__SymbolVisibility_enum_init},
}};

const upb_MiniTable google__protobuf__DescriptorProto_msg_init = {
  &google_protobuf_DescriptorProto__fields.fields[0],
  UPB_SIZE(64, 104), 11, kUpb_ExtMode_NonExtendable, 11, UPB_FASTTABLE_MASK(120), 0,
#ifdef UPB_TRACING_ENABLED
  "google.protobuf.DescriptorProto",
#endif
  UPB_FASTTABLE_INIT({
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x001000000000000a, &upb_DecodeFast_Bytes_Scalar_Tag1Byte},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x006000003f000052, &upb_DecodeFast_Bytes_Repeated_Tag1Byte},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
  })
};

typedef struct {
  upb_MiniTableField fields[3];
  upb_MiniTableSubInternal subs[1];
} google__protobuf__DescriptorProto__ExtensionRange_msg_init_Fields;

static const google__protobuf__DescriptorProto__ExtensionRange_msg_init_Fields google_protobuf_DescriptorProto_ExtensionRange__fields = {{
  {1, 12, 64, kUpb_NoSub, 5, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_4Byte << kUpb_FieldRep_Shift)},
  {2, 16, 65, kUpb_NoSub, 5, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_4Byte << kUpb_FieldRep_Shift)},
  {3, UPB_SIZE(20, 24), 66, UPB_SIZE(3, 4), 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
 },
  {
  {.UPB_PRIVATE(submsg) = &google__protobuf__ExtensionRangeOptions_msg_init},
}};

const upb_MiniTable google__protobuf__DescriptorProto__ExtensionRange_msg_init = {
  &google_protobuf_DescriptorProto_ExtensionRange__fields.fields[0],
  UPB_SIZE(24, 32), 3, kUpb_ExtMode_NonExtendable, 3, UPB_FASTTABLE_MASK(24), 0,
#ifdef UPB_TRACING_ENABLED
  "google.protobuf.DescriptorProto.ExtensionRange",
#endif
  UPB_FASTTABLE_INIT({
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x000c000000000008, &upb_DecodeFast_Varint32_Scalar_Tag1Byte},
    {0x0010000001000010, &upb_DecodeFast_Varint32_Scalar_Tag1Byte},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
  })
};

typedef struct {
  upb_MiniTableField fields[2];
} google__protobuf__DescriptorProto__ReservedRange_msg_init_Fields;

static const google__protobuf__DescriptorProto__ReservedRange_msg_init_Fields google_protobuf_DescriptorProto_ReservedRange__fields = {{
  {1, 12, 64, kUpb_NoSub, 5, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_4Byte << kUpb_FieldRep_Shift)},
  {2, 16, 65, kUpb_NoSub, 5, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_4Byte << kUpb_FieldRep_Shift)},
}};

const upb_MiniTable google__protobuf__DescriptorProto__ReservedRange_msg_init = {
  &google_protobuf_DescriptorProto_ReservedRange__fields.fields[0],
  24, 2, kUpb_ExtMode_NonExtendable, 2, UPB_FASTTABLE_MASK(24), 0,
#ifdef UPB_TRACING_ENABLED
  "google.protobuf.DescriptorProto.ReservedRange",
#endif
  UPB_FASTTABLE_INIT({
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x000c000000000008, &upb_DecodeFast_Varint32_Scalar_Tag1Byte},
    {0x0010000001000010, &upb_DecodeFast_Varint32_Scalar_Tag1Byte},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
  })
};

typedef struct {
  upb_MiniTableField fields[4];
  upb_MiniTableSubInternal subs[4];
} google__protobuf__ExtensionRangeOptions_msg_init_Fields;

static const google__protobuf__ExtensionRangeOptions_msg_init_Fields google_protobuf_ExtensionRangeOptions__fields = {{
  {2, UPB_SIZE(12, 16), 0, 12, 11, (int)kUpb_FieldMode_Array | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
  {3, UPB_SIZE(16, 12), 64, UPB_SIZE(10, 11), 14, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_4Byte << kUpb_FieldRep_Shift)},
  {50, UPB_SIZE(20, 24), 65, UPB_SIZE(8, 10), 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
  {999, UPB_SIZE(24, 32), 0, UPB_SIZE(6, 9), 11, (int)kUpb_FieldMode_Array | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
 },
  {
  {.UPB_PRIVATE(submsg) = &google__protobuf__ExtensionRangeOptions__Declaration_msg_init},
  {.UPB_PRIVATE(subenum) = &google__protobuf__ExtensionRangeOptions__VerificationState_enum_init},
  {.UPB_PRIVATE(submsg) = &google__protobuf__FeatureSet_msg_init},
  {.UPB_PRIVATE(submsg) = &google__protobuf__UninterpretedOption_msg_init},
}};

const upb_MiniTable google__protobuf__ExtensionRangeOptions_msg_init = {
  &google_protobuf_ExtensionRangeOptions__fields.fields[0],
  UPB_SIZE(32, 40), 4, kUpb_ExtMode_Extendable, 0, UPB_FASTTABLE_MASK(255), 0,
#ifdef UPB_TRACING_ENABLED
  "google.protobuf.ExtensionRangeOptions",
#endif
};

typedef struct {
  upb_MiniTableField fields[5];
} google__protobuf__ExtensionRangeOptions__Declaration_msg_init_Fields;

static const google__protobuf__ExtensionRangeOptions__Declaration_msg_init_Fields google_protobuf_ExtensionRangeOptions_Declaration__fields = {{
  {1, 12, 64, kUpb_NoSub, 5, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_4Byte << kUpb_FieldRep_Shift)},
  {2, 16, 65, kUpb_NoSub, 12, (int)kUpb_FieldMode_Scalar | (int)kUpb_LabelFlags_IsAlternate | ((int)kUpb_FieldRep_StringView << kUpb_FieldRep_Shift)},
  {3, UPB_SIZE(24, 32), 66, kUpb_NoSub, 12, (int)kUpb_FieldMode_Scalar | (int)kUpb_LabelFlags_IsAlternate | ((int)kUpb_FieldRep_StringView << kUpb_FieldRep_Shift)},
  {5, 9, 67, kUpb_NoSub, 8, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_1Byte << kUpb_FieldRep_Shift)},
  {6, 10, 68, kUpb_NoSub, 8, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_1Byte << kUpb_FieldRep_Shift)},
}};

const upb_MiniTable google__protobuf__ExtensionRangeOptions__Declaration_msg_init = {
  &google_protobuf_ExtensionRangeOptions_Declaration__fields.fields[0],
  UPB_SIZE(32, 48), 5, kUpb_ExtMode_NonExtendable, 3, UPB_FASTTABLE_MASK(56), 0,
#ifdef UPB_TRACING_ENABLED
  "google.protobuf.ExtensionRangeOptions.Declaration",
#endif
  UPB_FASTTABLE_INIT({
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x000c000000000008, &upb_DecodeFast_Varint32_Scalar_Tag1Byte},
    {0x0010000001000012, &upb_DecodeFast_Bytes_Scalar_Tag1Byte},
    {0x002000000200001a, &upb_DecodeFast_Bytes_Scalar_Tag1Byte},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0009000003000028, &upb_DecodeFast_Bool_Scalar_Tag1Byte},
    {0x000a000004000030, &upb_DecodeFast_Bool_Scalar_Tag1Byte},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
  })
};

typedef struct {
  upb_MiniTableField fields[11];
  upb_MiniTableSubInternal subs[3];
} google__protobuf__FieldDescriptorProto_msg_init_Fields;

static const google__protobuf__FieldDescriptorProto_msg_init_Fields google_protobuf_FieldDescriptorProto__fields = {{
  {1, 32, 64, kUpb_NoSub, 12, (int)kUpb_FieldMode_Scalar | (int)kUpb_LabelFlags_IsAlternate | ((int)kUpb_FieldRep_StringView << kUpb_FieldRep_Shift)},
  {2, UPB_SIZE(40, 48), 65, kUpb_NoSub, 12, (int)kUpb_FieldMode_Scalar | (int)kUpb_LabelFlags_IsAlternate | ((int)kUpb_FieldRep_StringView << kUpb_FieldRep_Shift)},
  {3, 12, 66, kUpb_NoSub, 5, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_4Byte << kUpb_FieldRep_Shift)},
  {4, 16, 67, UPB_SIZE(24, 25), 14, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_4Byte << kUpb_FieldRep_Shift)},
  {5, 20, 68, UPB_SIZE(22, 24), 14, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_4Byte << kUpb_FieldRep_Shift)},
  {6, UPB_SIZE(48, 64), 69, kUpb_NoSub, 12, (int)kUpb_FieldMode_Scalar | (int)kUpb_LabelFlags_IsAlternate | ((int)kUpb_FieldRep_StringView << kUpb_FieldRep_Shift)},
  {7, UPB_SIZE(56, 80), 70, kUpb_NoSub, 12, (int)kUpb_FieldMode_Scalar | (int)kUpb_LabelFlags_IsAlternate | ((int)kUpb_FieldRep_StringView << kUpb_FieldRep_Shift)},
  {8, UPB_SIZE(24, 112), 71, UPB_SIZE(14, 17), 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
  {9, UPB_SIZE(28, 24), 72, kUpb_NoSub, 5, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_4Byte << kUpb_FieldRep_Shift)},
  {10, UPB_SIZE(64, 96), 73, kUpb_NoSub, 12, (int)kUpb_FieldMode_Scalar | (int)kUpb_LabelFlags_IsAlternate | ((int)kUpb_FieldRep_StringView << kUpb_FieldRep_Shift)},
  {17, 10, 74, kUpb_NoSub, 8, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_1Byte << kUpb_FieldRep_Shift)},
 },
  {
  {.UPB_PRIVATE(subenum) = &google__protobuf__FieldDescriptorProto__Label_enum_init},
  {.UPB_PRIVATE(subenum) = &google__protobuf__FieldDescriptorProto__Type_enum_init},
  {.UPB_PRIVATE(submsg) = &google__protobuf__FieldOptions_msg_init},
}};

const upb_MiniTable google__protobuf__FieldDescriptorProto_msg_init = {
  &google_protobuf_FieldDescriptorProto__fields.fields[0],
  UPB_SIZE(72, 120), 11, kUpb_ExtMode_NonExtendable, 10, UPB_FASTTABLE_MASK(248), 0,
#ifdef UPB_TRACING_ENABLED
  "google.protobuf.FieldDescriptorProto",
#endif
  UPB_FASTTABLE_INIT({
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x002000000000000a, &upb_DecodeFast_Bytes_Scalar_Tag1Byte},
    {0x0030000001000012, &upb_DecodeFast_Bytes_Scalar_Tag1Byte},
    {0x000c000002000018, &upb_DecodeFast_Varint32_Scalar_Tag1Byte},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0040000005000032, &upb_DecodeFast_Bytes_Scalar_Tag1Byte},
    {0x005000000600003a, &upb_DecodeFast_Bytes_Scalar_Tag1Byte},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0018000008000048, &upb_DecodeFast_Varint32_Scalar_Tag1Byte},
    {0x0060000009000052, &upb_DecodeFast_Bytes_Scalar_Tag1Byte},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x000a00000a000188, &upb_DecodeFast_Bool_Scalar_Tag2Byte},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
  })
};

typedef struct {
  upb_MiniTableField fields[2];
  upb_MiniTableSubInternal subs[1];
} google__protobuf__OneofDescriptorProto_msg_init_Fields;

static const google__protobuf__OneofDescriptorProto_msg_init_Fields google_protobuf_OneofDescriptorProto__fields = {{
  {1, 16, 64, kUpb_NoSub, 12, (int)kUpb_FieldMode_Scalar | (int)kUpb_LabelFlags_IsAlternate | ((int)kUpb_FieldRep_StringView << kUpb_FieldRep_Shift)},
  {2, UPB_SIZE(12, 32), 65, 3, 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
 },
  {
  {.UPB_PRIVATE(submsg) = &google__protobuf__OneofOptions_msg_init},
}};

const upb_MiniTable google__protobuf__OneofDescriptorProto_msg_init = {
  &google_protobuf_OneofDescriptorProto__fields.fields[0],
  UPB_SIZE(24, 40), 2, kUpb_ExtMode_NonExtendable, 2, UPB_FASTTABLE_MASK(8), 0,
#ifdef UPB_TRACING_ENABLED
  "google.protobuf.OneofDescriptorProto",
#endif
  UPB_FASTTABLE_INIT({
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x001000000000000a, &upb_DecodeFast_Bytes_Scalar_Tag1Byte},
  })
};

typedef struct {
  upb_MiniTableField fields[6];
  upb_MiniTableSubInternal subs[4];
} google__protobuf__EnumDescriptorProto_msg_init_Fields;

static const google__protobuf__EnumDescriptorProto_msg_init_Fields google_protobuf_EnumDescriptorProto__fields = {{
  {1, UPB_SIZE(32, 16), 64, kUpb_NoSub, 12, (int)kUpb_FieldMode_Scalar | (int)kUpb_LabelFlags_IsAlternate | ((int)kUpb_FieldRep_StringView << kUpb_FieldRep_Shift)},
  {2, UPB_SIZE(12, 32), 0, 15, 11, (int)kUpb_FieldMode_Array | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
  {3, UPB_SIZE(16, 40), 65, UPB_SIZE(13, 14), 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
  {4, UPB_SIZE(20, 48), 0, UPB_SIZE(11, 13), 11, (int)kUpb_FieldMode_Array | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
  {5, UPB_SIZE(24, 56), 0, kUpb_NoSub, 12, (int)kUpb_FieldMode_Array | (int)kUpb_LabelFlags_IsAlternate | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
  {6, UPB_SIZE(28, 12), 66, UPB_SIZE(6, 9), 14, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_4Byte << kUpb_FieldRep_Shift)},
 },
  {
  {.UPB_PRIVATE(submsg) = &google__protobuf__EnumValueDescriptorProto_msg_init},
  {.UPB_PRIVATE(submsg) = &google__protobuf__EnumOptions_msg_init},
  {.UPB_PRIVATE(submsg) = &google__protobuf__EnumDescriptorProto__EnumReservedRange_msg_init},
  {.UPB_PRIVATE(subenum) = &google__protobuf__SymbolVisibility_enum_init},
}};

const upb_MiniTable google__protobuf__EnumDescriptorProto_msg_init = {
  &google_protobuf_EnumDescriptorProto__fields.fields[0],
  UPB_SIZE(40, 64), 6, kUpb_ExtMode_NonExtendable, 6, UPB_FASTTABLE_MASK(56), 0,
#ifdef UPB_TRACING_ENABLED
  "google.protobuf.EnumDescriptorProto",
#endif
  UPB_FASTTABLE_INIT({
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x001000000000000a, &upb_DecodeFast_Bytes_Scalar_Tag1Byte},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x003800003f00002a, &upb_DecodeFast_Bytes_Repeated_Tag1Byte},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
  })
};

typedef struct {
  upb_MiniTableField fields[2];
} google__protobuf__EnumDescriptorProto__EnumReservedRange_msg_init_Fields;

static const google__protobuf__EnumDescriptorProto__EnumReservedRange_msg_init_Fields google_protobuf_EnumDescriptorProto_EnumReservedRange__fields = {{
  {1, 12, 64, kUpb_NoSub, 5, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_4Byte << kUpb_FieldRep_Shift)},
  {2, 16, 65, kUpb_NoSub, 5, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_4Byte << kUpb_FieldRep_Shift)},
}};

const upb_MiniTable google__protobuf__EnumDescriptorProto__EnumReservedRange_msg_init = {
  &google_protobuf_EnumDescriptorProto_EnumReservedRange__fields.fields[0],
  24, 2, kUpb_ExtMode_NonExtendable, 2, UPB_FASTTABLE_MASK(24), 0,
#ifdef UPB_TRACING_ENABLED
  "google.protobuf.EnumDescriptorProto.EnumReservedRange",
#endif
  UPB_FASTTABLE_INIT({
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x000c000000000008, &upb_DecodeFast_Varint32_Scalar_Tag1Byte},
    {0x0010000001000010, &upb_DecodeFast_Varint32_Scalar_Tag1Byte},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
  })
};

typedef struct {
  upb_MiniTableField fields[3];
  upb_MiniTableSubInternal subs[1];
} google__protobuf__EnumValueDescriptorProto_msg_init_Fields;

static const google__protobuf__EnumValueDescriptorProto_msg_init_Fields google_protobuf_EnumValueDescriptorProto__fields = {{
  {1, UPB_SIZE(20, 16), 64, kUpb_NoSub, 12, (int)kUpb_FieldMode_Scalar | (int)kUpb_LabelFlags_IsAlternate | ((int)kUpb_FieldRep_StringView << kUpb_FieldRep_Shift)},
  {2, 12, 65, kUpb_NoSub, 5, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_4Byte << kUpb_FieldRep_Shift)},
  {3, UPB_SIZE(16, 32), 66, UPB_SIZE(3, 4), 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
 },
  {
  {.UPB_PRIVATE(submsg) = &google__protobuf__EnumValueOptions_msg_init},
}};

const upb_MiniTable google__protobuf__EnumValueDescriptorProto_msg_init = {
  &google_protobuf_EnumValueDescriptorProto__fields.fields[0],
  UPB_SIZE(32, 40), 3, kUpb_ExtMode_NonExtendable, 3, UPB_FASTTABLE_MASK(24), 0,
#ifdef UPB_TRACING_ENABLED
  "google.protobuf.EnumValueDescriptorProto",
#endif
  UPB_FASTTABLE_INIT({
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x001000000000000a, &upb_DecodeFast_Bytes_Scalar_Tag1Byte},
    {0x000c000001000010, &upb_DecodeFast_Varint32_Scalar_Tag1Byte},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
  })
};

typedef struct {
  upb_MiniTableField fields[3];
  upb_MiniTableSubInternal subs[2];
} google__protobuf__ServiceDescriptorProto_msg_init_Fields;

static const google__protobuf__ServiceDescriptorProto_msg_init_Fields google_protobuf_ServiceDescriptorProto__fields = {{
  {1, UPB_SIZE(20, 16), 64, kUpb_NoSub, 12, (int)kUpb_FieldMode_Scalar | (int)kUpb_LabelFlags_IsAlternate | ((int)kUpb_FieldRep_StringView << kUpb_FieldRep_Shift)},
  {2, UPB_SIZE(12, 32), 0, UPB_SIZE(6, 7), 11, (int)kUpb_FieldMode_Array | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
  {3, UPB_SIZE(16, 40), 65, UPB_SIZE(4, 6), 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
 },
  {
  {.UPB_PRIVATE(submsg) = &google__protobuf__MethodDescriptorProto_msg_init},
  {.UPB_PRIVATE(submsg) = &google__protobuf__ServiceOptions_msg_init},
}};

const upb_MiniTable google__protobuf__ServiceDescriptorProto_msg_init = {
  &google_protobuf_ServiceDescriptorProto__fields.fields[0],
  UPB_SIZE(32, 48), 3, kUpb_ExtMode_NonExtendable, 3, UPB_FASTTABLE_MASK(8), 0,
#ifdef UPB_TRACING_ENABLED
  "google.protobuf.ServiceDescriptorProto",
#endif
  UPB_FASTTABLE_INIT({
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x001000000000000a, &upb_DecodeFast_Bytes_Scalar_Tag1Byte},
  })
};

typedef struct {
  upb_MiniTableField fields[6];
  upb_MiniTableSubInternal subs[1];
} google__protobuf__MethodDescriptorProto_msg_init_Fields;

static const google__protobuf__MethodDescriptorProto_msg_init_Fields google_protobuf_MethodDescriptorProto__fields = {{
  {1, 16, 64, kUpb_NoSub, 12, (int)kUpb_FieldMode_Scalar | (int)kUpb_LabelFlags_IsAlternate | ((int)kUpb_FieldRep_StringView << kUpb_FieldRep_Shift)},
  {2, UPB_SIZE(24, 32), 65, kUpb_NoSub, 12, (int)kUpb_FieldMode_Scalar | (int)kUpb_LabelFlags_IsAlternate | ((int)kUpb_FieldRep_StringView << kUpb_FieldRep_Shift)},
  {3, UPB_SIZE(32, 48), 66, kUpb_NoSub, 12, (int)kUpb_FieldMode_Scalar | (int)kUpb_LabelFlags_IsAlternate | ((int)kUpb_FieldRep_StringView << kUpb_FieldRep_Shift)},
  {4, UPB_SIZE(12, 64), 67, 9, 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
  {5, 9, 68, kUpb_NoSub, 8, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_1Byte << kUpb_FieldRep_Shift)},
  {6, 10, 69, kUpb_NoSub, 8, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_1Byte << kUpb_FieldRep_Shift)},
 },
  {
  {.UPB_PRIVATE(submsg) = &google__protobuf__MethodOptions_msg_init},
}};

const upb_MiniTable google__protobuf__MethodDescriptorProto_msg_init = {
  &google_protobuf_MethodDescriptorProto__fields.fields[0],
  UPB_SIZE(40, 72), 6, kUpb_ExtMode_NonExtendable, 6, UPB_FASTTABLE_MASK(56), 0,
#ifdef UPB_TRACING_ENABLED
  "google.protobuf.MethodDescriptorProto",
#endif
  UPB_FASTTABLE_INIT({
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x001000000000000a, &upb_DecodeFast_Bytes_Scalar_Tag1Byte},
    {0x0020000001000012, &upb_DecodeFast_Bytes_Scalar_Tag1Byte},
    {0x003000000200001a, &upb_DecodeFast_Bytes_Scalar_Tag1Byte},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0009000004000028, &upb_DecodeFast_Bool_Scalar_Tag1Byte},
    {0x000a000005000030, &upb_DecodeFast_Bool_Scalar_Tag1Byte},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
  })
};

typedef struct {
  upb_MiniTableField fields[21];
  upb_MiniTableSubInternal subs[3];
} google__protobuf__FileOptions_msg_init_Fields;

static const google__protobuf__FileOptions_msg_init_Fields google_protobuf_FileOptions__fields = {{
  {1, UPB_SIZE(32, 24), 64, kUpb_NoSub, 12, (int)kUpb_FieldMode_Scalar | (int)kUpb_LabelFlags_IsAlternate | ((int)kUpb_FieldRep_StringView << kUpb_FieldRep_Shift)},
  {8, 40, 65, kUpb_NoSub, 12, (int)kUpb_FieldMode_Scalar | (int)kUpb_LabelFlags_IsAlternate | ((int)kUpb_FieldRep_StringView << kUpb_FieldRep_Shift)},
  {9, 20, 66, UPB_SIZE(57, 58), 14, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_4Byte << kUpb_FieldRep_Shift)},
  {10, 11, 67, kUpb_NoSub, 8, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_1Byte << kUpb_FieldRep_Shift)},
  {11, UPB_SIZE(48, 56), 68, kUpb_NoSub, 12, (int)kUpb_FieldMode_Scalar | (int)kUpb_LabelFlags_IsAlternate | ((int)kUpb_FieldRep_StringView << kUpb_FieldRep_Shift)},
  {16, 12, 69, kUpb_NoSub, 8, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_1Byte << kUpb_FieldRep_Shift)},
  {17, 13, 70, kUpb_NoSub, 8, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_1Byte << kUpb_FieldRep_Shift)},
  {18, 14, 71, kUpb_NoSub, 8, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_1Byte << kUpb_FieldRep_Shift)},
  {20, 15, 72, kUpb_NoSub, 8, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_1Byte << kUpb_FieldRep_Shift)},
  {23, 16, 73, kUpb_NoSub, 8, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_1Byte << kUpb_FieldRep_Shift)},
  {27, 17, 74, kUpb_NoSub, 8, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_1Byte << kUpb_FieldRep_Shift)},
  {31, 18, 75, kUpb_NoSub, 8, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_1Byte << kUpb_FieldRep_Shift)},
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  {37, UPB_SIZE(64, 88), 77, kUpb_NoSub, 12, (int)kUpb_FieldMode_Scalar | (int)kUpb_LabelFlags_IsAlternate | ((int)kUpb_FieldRep_StringView << kUpb_FieldRep_Shift)},
  {39, UPB_SIZE(72, 104), 78, kUpb_NoSub, 12, (int)kUpb_FieldMode_Scalar | (int)kUpb_LabelFlags_IsAlternate | ((int)kUpb_FieldRep_StringView << kUpb_FieldRep_Shift)},
  {40, UPB_SIZE(80, 120), 79, kUpb_NoSub, 12, (int)kUpb_FieldMode_Scalar | (int)kUpb_LabelFlags_IsAlternate | ((int)kUpb_FieldRep_StringView << kUpb_FieldRep_Shift)},
  {41, UPB_SIZE(88, 136), 80, kUpb_NoSub, 12, (int)kUpb_FieldMode_Scalar | (int)kUpb_LabelFlags_IsAlternate | ((int)kUpb_FieldRep_StringView << kUpb_FieldRep_Shift)},
  {44, UPB_SIZE(96, 152), 81, kUpb_NoSub, 12, (int)kUpb_FieldMode_Scalar | (int)kUpb_LabelFlags_IsAlternate | ((int)kUpb_FieldRep_StringView << kUpb_FieldRep_Shift)},
  {45, UPB_SIZE(104, 168), 82, kUpb_NoSub, 12, (int)kUpb_FieldMode_Scalar | (int)kUpb_LabelFlags_IsAlternate | ((int)kUpb_FieldRep_StringView << kUpb_FieldRep_Shift)},
  {50, UPB_SIZE(24, 184), 83, UPB_SIZE(7, 9), 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
  {999, UPB_SIZE(28, 192), 0, UPB_SIZE(5, 8), 11, (int)kUpb_FieldMode_Array | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
 },
  {
  {.UPB_PRIVATE(subenum) = &google__protobuf__FileOptions__OptimizeMode_enum_init},
  {.UPB_PRIVATE(submsg) = &google__protobuf__FeatureSet_msg_init},
  {.UPB_PRIVATE(submsg) = &google__protobuf__UninterpretedOption_msg_init},
}};

const upb_MiniTable google__protobuf__FileOptions_msg_init = {
  &google_protobuf_FileOptions__fields.fields[0],
  UPB_SIZE(112, 200), 21, kUpb_ExtMode_Extendable, 1, UPB_FASTTABLE_MASK(248), 0,
#ifdef UPB_TRACING_ENABLED
  "google.protobuf.FileOptions",
#endif
  UPB_FASTTABLE_INIT({
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x001800000000000a, &upb_DecodeFast_Bytes_Scalar_Tag1Byte},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0028000001000042, &upb_DecodeFast_Bytes_Scalar_Tag1Byte},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x000b000003000050, &upb_DecodeFast_Bool_Scalar_Tag1Byte},
    {0x003800000400005a, &upb_DecodeFast_Bytes_Scalar_Tag1Byte},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x000c000005000180, &upb_DecodeFast_Bool_Scalar_Tag2Byte},
    {0x000d000006000188, &upb_DecodeFast_Bool_Scalar_Tag2Byte},
    {0x000e000007000190, &upb_DecodeFast_Bool_Scalar_Tag2Byte},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x000f0000080001a0, &upb_DecodeFast_Bool_Scalar_Tag2Byte},
    {0x005800000d0002aa, &upb_DecodeFast_Bytes_Scalar_Tag2Byte},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x00100000090001b8, &upb_DecodeFast_Bool_Scalar_Tag2Byte},
    {0x007800000f0002c2, &upb_DecodeFast_Bytes_Scalar_Tag2Byte},
    {0x00880000100002ca, &upb_DecodeFast_Bytes_Scalar_Tag2Byte},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x001100000a0001d8, &upb_DecodeFast_Bool_Scalar_Tag2Byte},
    {0x00980000110002e2, &upb_DecodeFast_Bytes_Scalar_Tag2Byte},
    {0x00a80000120002ea, &upb_DecodeFast_Bytes_Scalar_Tag2Byte},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x001200000b0001f8, &upb_DecodeFast_Bool_Scalar_Tag2Byte},
  })
};

typedef struct {
  upb_MiniTableField fields[7];
  upb_MiniTableSubInternal subs[2];
} google__protobuf__MessageOptions_msg_init_Fields;

static const google__protobuf__MessageOptions_msg_init_Fields google_protobuf_MessageOptions__fields = {{
  {1, 9, 64, kUpb_NoSub, 8, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_1Byte << kUpb_FieldRep_Shift)},
  {2, 10, 65, kUpb_NoSub, 8, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_1Byte << kUpb_FieldRep_Shift)},
  {3, 11, 66, kUpb_NoSub, 8, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_1Byte << kUpb_FieldRep_Shift)},
  {7, 12, 67, kUpb_NoSub, 8, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_1Byte << kUpb_FieldRep_Shift)},
  {11, 13, 68, kUpb_NoSub, 8, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_1Byte << kUpb_FieldRep_Shift)},
  {12, 16, 69, UPB_SIZE(6, 7), 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
  {999, UPB_SIZE(20, 24), 0, UPB_SIZE(4, 6), 11, (int)kUpb_FieldMode_Array | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
 },
  {
  {.UPB_PRIVATE(submsg) = &google__protobuf__FeatureSet_msg_init},
  {.UPB_PRIVATE(submsg) = &google__protobuf__UninterpretedOption_msg_init},
}};

const upb_MiniTable google__protobuf__MessageOptions_msg_init = {
  &google_protobuf_MessageOptions__fields.fields[0],
  UPB_SIZE(24, 32), 7, kUpb_ExtMode_Extendable, 3, UPB_FASTTABLE_MASK(120), 0,
#ifdef UPB_TRACING_ENABLED
  "google.protobuf.MessageOptions",
#endif
  UPB_FASTTABLE_INIT({
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0009000000000008, &upb_DecodeFast_Bool_Scalar_Tag1Byte},
    {0x000a000001000010, &upb_DecodeFast_Bool_Scalar_Tag1Byte},
    {0x000b000002000018, &upb_DecodeFast_Bool_Scalar_Tag1Byte},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x000c000003000038, &upb_DecodeFast_Bool_Scalar_Tag1Byte},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x000d000004000058, &upb_DecodeFast_Bool_Scalar_Tag1Byte},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
  })
};

typedef struct {
  upb_MiniTableField fields[14];
  upb_MiniTableSubInternal subs[8];
} google__protobuf__FieldOptions_msg_init_Fields;

static const google__protobuf__FieldOptions_msg_init_Fields google_protobuf_FieldOptions__fields = {{
  {1, 16, 64, 42, 14, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_4Byte << kUpb_FieldRep_Shift)},
  {2, 10, 65, kUpb_NoSub, 8, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_1Byte << kUpb_FieldRep_Shift)},
  {3, 11, 66, kUpb_NoSub, 8, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_1Byte << kUpb_FieldRep_Shift)},
  {5, 12, 67, kUpb_NoSub, 8, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_1Byte << kUpb_FieldRep_Shift)},
  {6, 20, 68, UPB_SIZE(31, 32), 14, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_4Byte << kUpb_FieldRep_Shift)},
  {10, 13, 69, kUpb_NoSub, 8, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_1Byte << kUpb_FieldRep_Shift)},
  {15, 14, 70, kUpb_NoSub, 8, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_1Byte << kUpb_FieldRep_Shift)},
  {16, 15, 71, kUpb_NoSub, 8, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_1Byte << kUpb_FieldRep_Shift)},
  {17, 24, 72, UPB_SIZE(20, 22), 14, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_4Byte << kUpb_FieldRep_Shift)},
  {19, UPB_SIZE(28, 32), 0, UPB_SIZE(18, 21), 14, (int)kUpb_FieldMode_Array | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
  {20, UPB_SIZE(32, 40), 0, UPB_SIZE(16, 20), 11, (int)kUpb_FieldMode_Array | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
  {21, UPB_SIZE(36, 48), 73, UPB_SIZE(14, 19), 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
  {22, UPB_SIZE(40, 56), 74, UPB_SIZE(12, 18), 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
  {999, UPB_SIZE(44, 64), 0, UPB_SIZE(10, 17), 11, (int)kUpb_FieldMode_Array | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
 },
  {
  {.UPB_PRIVATE(subenum) = &google__protobuf__FieldOptions__CType_enum_init},
  {.UPB_PRIVATE(subenum) = &google__protobuf__FieldOptions__JSType_enum_init},
  {.UPB_PRIVATE(subenum) = &google__protobuf__FieldOptions__OptionRetention_enum_init},
  {.UPB_PRIVATE(subenum) = &google__protobuf__FieldOptions__OptionTargetType_enum_init},
  {.UPB_PRIVATE(submsg) = &google__protobuf__FieldOptions__EditionDefault_msg_init},
  {.UPB_PRIVATE(submsg) = &google__protobuf__FeatureSet_msg_init},
  {.UPB_PRIVATE(submsg) = &google__protobuf__FieldOptions__FeatureSupport_msg_init},
  {.UPB_PRIVATE(submsg) = &google__protobuf__UninterpretedOption_msg_init},
}};

const upb_MiniTable google__protobuf__FieldOptions_msg_init = {
  &google_protobuf_FieldOptions__fields.fields[0],
  UPB_SIZE(48, 72), 14, kUpb_ExtMode_Extendable, 3, UPB_FASTTABLE_MASK(248), 0,
#ifdef UPB_TRACING_ENABLED
  "google.protobuf.FieldOptions",
#endif
  UPB_FASTTABLE_INIT({
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x000a000001000010, &upb_DecodeFast_Bool_Scalar_Tag1Byte},
    {0x000b000002000018, &upb_DecodeFast_Bool_Scalar_Tag1Byte},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x000c000003000028, &upb_DecodeFast_Bool_Scalar_Tag1Byte},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x000d000005000050, &upb_DecodeFast_Bool_Scalar_Tag1Byte},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x000e000006000078, &upb_DecodeFast_Bool_Scalar_Tag1Byte},
    {0x000f000007000180, &upb_DecodeFast_Bool_Scalar_Tag2Byte},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
  })
};

typedef struct {
  upb_MiniTableField fields[2];
  upb_MiniTableSubInternal subs[1];
} google__protobuf__FieldOptions__EditionDefault_msg_init_Fields;

static const google__protobuf__FieldOptions__EditionDefault_msg_init_Fields google_protobuf_FieldOptions_EditionDefault__fields = {{
  {2, 16, 64, kUpb_NoSub, 12, (int)kUpb_FieldMode_Scalar | (int)kUpb_LabelFlags_IsAlternate | ((int)kUpb_FieldRep_StringView << kUpb_FieldRep_Shift)},
  {3, 12, 65, 3, 14, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_4Byte << kUpb_FieldRep_Shift)},
 },
  {
  {.UPB_PRIVATE(subenum) = &google__protobuf__Edition_enum_init},
}};

const upb_MiniTable google__protobuf__FieldOptions__EditionDefault_msg_init = {
  &google_protobuf_FieldOptions_EditionDefault__fields.fields[0],
  UPB_SIZE(24, 32), 2, kUpb_ExtMode_NonExtendable, 0, UPB_FASTTABLE_MASK(24), 0,
#ifdef UPB_TRACING_ENABLED
  "google.protobuf.FieldOptions.EditionDefault",
#endif
  UPB_FASTTABLE_INIT({
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0010000000000012, &upb_DecodeFast_Bytes_Scalar_Tag1Byte},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
  })
};

typedef struct {
  upb_MiniTableField fields[5];
  upb_MiniTableSubInternal subs[3];
} google__protobuf__FieldOptions__FeatureSupport_msg_init_Fields;

static const google__protobuf__FieldOptions__FeatureSupport_msg_init_Fields google_protobuf_FieldOptions_FeatureSupport__fields = {{
  {1, 12, 64, UPB_SIZE(15, 16), 14, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_4Byte << kUpb_FieldRep_Shift)},
  {2, 16, 65, UPB_SIZE(13, 15), 14, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_4Byte << kUpb_FieldRep_Shift)},
  {3, 24, 66, kUpb_NoSub, 12, (int)kUpb_FieldMode_Scalar | (int)kUpb_LabelFlags_IsAlternate | ((int)kUpb_FieldRep_StringView << kUpb_FieldRep_Shift)},
  {4, 20, 67, UPB_SIZE(8, 11), 14, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_4Byte << kUpb_FieldRep_Shift)},
  {5, UPB_SIZE(32, 40), 68, kUpb_NoSub, 12, (int)kUpb_FieldMode_Scalar | (int)kUpb_LabelFlags_IsAlternate | ((int)kUpb_FieldRep_StringView << kUpb_FieldRep_Shift)},
 },
  {
  {.UPB_PRIVATE(subenum) = &google__protobuf__Edition_enum_init},
  {.UPB_PRIVATE(subenum) = &google__protobuf__Edition_enum_init},
  {.UPB_PRIVATE(subenum) = &google__protobuf__Edition_enum_init},
}};

const upb_MiniTable google__protobuf__FieldOptions__FeatureSupport_msg_init = {
  &google_protobuf_FieldOptions_FeatureSupport__fields.fields[0],
  UPB_SIZE(40, 56), 5, kUpb_ExtMode_NonExtendable, 5, UPB_FASTTABLE_MASK(56), 0,
#ifdef UPB_TRACING_ENABLED
  "google.protobuf.FieldOptions.FeatureSupport",
#endif
  UPB_FASTTABLE_INIT({
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x001800000200001a, &upb_DecodeFast_Bytes_Scalar_Tag1Byte},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x002800000400002a, &upb_DecodeFast_Bytes_Scalar_Tag1Byte},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
  })
};

typedef struct {
  upb_MiniTableField fields[2];
  upb_MiniTableSubInternal subs[2];
} google__protobuf__OneofOptions_msg_init_Fields;

static const google__protobuf__OneofOptions_msg_init_Fields google_protobuf_OneofOptions__fields = {{
  {1, UPB_SIZE(12, 16), 64, 6, 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
  {999, UPB_SIZE(16, 24), 0, UPB_SIZE(4, 5), 11, (int)kUpb_FieldMode_Array | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
 },
  {
  {.UPB_PRIVATE(submsg) = &google__protobuf__FeatureSet_msg_init},
  {.UPB_PRIVATE(submsg) = &google__protobuf__UninterpretedOption_msg_init},
}};

const upb_MiniTable google__protobuf__OneofOptions_msg_init = {
  &google_protobuf_OneofOptions__fields.fields[0],
  UPB_SIZE(24, 32), 2, kUpb_ExtMode_Extendable, 1, UPB_FASTTABLE_MASK(255), 0,
#ifdef UPB_TRACING_ENABLED
  "google.protobuf.OneofOptions",
#endif
};

typedef struct {
  upb_MiniTableField fields[5];
  upb_MiniTableSubInternal subs[2];
} google__protobuf__EnumOptions_msg_init_Fields;

static const google__protobuf__EnumOptions_msg_init_Fields google_protobuf_EnumOptions__fields = {{
  {2, 9, 64, kUpb_NoSub, 8, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_1Byte << kUpb_FieldRep_Shift)},
  {3, 10, 65, kUpb_NoSub, 8, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_1Byte << kUpb_FieldRep_Shift)},
  {6, 11, 66, kUpb_NoSub, 8, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_1Byte << kUpb_FieldRep_Shift)},
  {7, UPB_SIZE(12, 16), 67, UPB_SIZE(6, 7), 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
  {999, UPB_SIZE(16, 24), 0, UPB_SIZE(4, 6), 11, (int)kUpb_FieldMode_Array | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
 },
  {
  {.UPB_PRIVATE(submsg) = &google__protobuf__FeatureSet_msg_init},
  {.UPB_PRIVATE(submsg) = &google__protobuf__UninterpretedOption_msg_init},
}};

const upb_MiniTable google__protobuf__EnumOptions_msg_init = {
  &google_protobuf_EnumOptions__fields.fields[0],
  UPB_SIZE(24, 32), 5, kUpb_ExtMode_Extendable, 0, UPB_FASTTABLE_MASK(56), 0,
#ifdef UPB_TRACING_ENABLED
  "google.protobuf.EnumOptions",
#endif
  UPB_FASTTABLE_INIT({
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0009000000000010, &upb_DecodeFast_Bool_Scalar_Tag1Byte},
    {0x000a000001000018, &upb_DecodeFast_Bool_Scalar_Tag1Byte},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x000b000002000030, &upb_DecodeFast_Bool_Scalar_Tag1Byte},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
  })
};

typedef struct {
  upb_MiniTableField fields[5];
  upb_MiniTableSubInternal subs[3];
} google__protobuf__EnumValueOptions_msg_init_Fields;

static const google__protobuf__EnumValueOptions_msg_init_Fields google_protobuf_EnumValueOptions__fields = {{
  {1, 9, 64, kUpb_NoSub, 8, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_1Byte << kUpb_FieldRep_Shift)},
  {2, UPB_SIZE(12, 16), 65, UPB_SIZE(12, 13), 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
  {3, 10, 66, kUpb_NoSub, 8, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_1Byte << kUpb_FieldRep_Shift)},
  {4, UPB_SIZE(16, 24), 67, UPB_SIZE(7, 9), 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
  {999, UPB_SIZE(20, 32), 0, UPB_SIZE(5, 8), 11, (int)kUpb_FieldMode_Array | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
 },
  {
  {.UPB_PRIVATE(submsg) = &google__protobuf__FeatureSet_msg_init},
  {.UPB_PRIVATE(submsg) = &google__protobuf__FieldOptions__FeatureSupport_msg_init},
  {.UPB_PRIVATE(submsg) = &google__protobuf__UninterpretedOption_msg_init},
}};

const upb_MiniTable google__protobuf__EnumValueOptions_msg_init = {
  &google_protobuf_EnumValueOptions__fields.fields[0],
  UPB_SIZE(24, 40), 5, kUpb_ExtMode_Extendable, 4, UPB_FASTTABLE_MASK(24), 0,
#ifdef UPB_TRACING_ENABLED
  "google.protobuf.EnumValueOptions",
#endif
  UPB_FASTTABLE_INIT({
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0009000000000008, &upb_DecodeFast_Bool_Scalar_Tag1Byte},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x000a000002000018, &upb_DecodeFast_Bool_Scalar_Tag1Byte},
  })
};

typedef struct {
  upb_MiniTableField fields[3];
  upb_MiniTableSubInternal subs[2];
} google__protobuf__ServiceOptions_msg_init_Fields;

static const google__protobuf__ServiceOptions_msg_init_Fields google_protobuf_ServiceOptions__fields = {{
  {33, 9, 64, kUpb_NoSub, 8, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_1Byte << kUpb_FieldRep_Shift)},
  {34, UPB_SIZE(12, 16), 65, UPB_SIZE(6, 7), 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
  {999, UPB_SIZE(16, 24), 0, UPB_SIZE(4, 6), 11, (int)kUpb_FieldMode_Array | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
 },
  {
  {.UPB_PRIVATE(submsg) = &google__protobuf__FeatureSet_msg_init},
  {.UPB_PRIVATE(submsg) = &google__protobuf__UninterpretedOption_msg_init},
}};

const upb_MiniTable google__protobuf__ServiceOptions_msg_init = {
  &google_protobuf_ServiceOptions__fields.fields[0],
  UPB_SIZE(24, 32), 3, kUpb_ExtMode_Extendable, 0, UPB_FASTTABLE_MASK(248), 0,
#ifdef UPB_TRACING_ENABLED
  "google.protobuf.ServiceOptions",
#endif
  UPB_FASTTABLE_INIT({
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0009000000000288, &upb_DecodeFast_Bool_Scalar_Tag2Byte},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
  })
};

typedef struct {
  upb_MiniTableField fields[4];
  upb_MiniTableSubInternal subs[3];
} google__protobuf__MethodOptions_msg_init_Fields;

static const google__protobuf__MethodOptions_msg_init_Fields google_protobuf_MethodOptions__fields = {{
  {33, 9, 64, kUpb_NoSub, 8, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_1Byte << kUpb_FieldRep_Shift)},
  {34, 12, 65, 9, 14, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_4Byte << kUpb_FieldRep_Shift)},
  {35, 16, 66, UPB_SIZE(7, 8), 11, (int)kUpb_FieldMode_Scalar | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
  {999, UPB_SIZE(20, 24), 0, UPB_SIZE(5, 7), 11, (int)kUpb_FieldMode_Array | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
 },
  {
  {.UPB_PRIVATE(subenum) = &google__protobuf__MethodOptions__IdempotencyLevel_enum_init},
  {.UPB_PRIVATE(submsg) = &google__protobuf__FeatureSet_msg_init},
  {.UPB_PRIVATE(submsg) = &google__protobuf__UninterpretedOption_msg_init},
}};

const upb_MiniTable google__protobuf__MethodOptions_msg_init = {
  &google_protobuf_MethodOptions__fields.fields[0],
  UPB_SIZE(24, 32), 4, kUpb_ExtMode_Extendable, 0, UPB_FASTTABLE_MASK(248), 0,
#ifdef UPB_TRACING_ENABLED
  "google.protobuf.MethodOptions",
#endif
  UPB_FASTTABLE_INIT({
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0009000000000288, &upb_DecodeFast_Bool_Scalar_Tag2Byte},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
    {0x0000000000000000, &_upb_FastDecoder_DecodeGeneric},
  })
};

typedef struct {
  upb_MiniTableField fields[7];
  upb_MiniTableSubInternal subs[1];
} google__protobuf__UninterpretedOption_msg_init_Fields;

static const google__protobuf__UninterpretedOption_msg_init_Fields google_protobuf_UninterpretedOption__fields = {{
  {2, UPB_SIZE(12, 64), 0, UPB_SIZE(21, 22), 11, (int)kUpb_FieldMode_Array | ((int)UPB_SIZE(kUpb_FieldRep_4Byte, kUpb_FieldRep_8Byte) << kUpb_FieldRep_Shift)},
  {3, 16, 64, kUpb_NoSub, 12, (int)kUpb_FieldMode_Scalar | (int)kUpb_LabelFlags_IsAlternate | ((int)kUpb_FieldRep_StringView << kUpb_FieldRep_Shift)},
  {4, UPB_SIZE(40, 72), 65, kUpb_NoSub, 4, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_8Byte << kUpb_FieldRep_Shift)},
  {5, UPB_SIZE(48, 80), 66, kUpb_NoSub, 3, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_8Byte << kUpb_FieldRep_Shift)},
  {6, UPB_SIZE(56, 88), 67, kUpb_NoSub, 1, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_8Byte << kUpb_FieldRep_Shift)},
  {7, UPB_SIZE(24, 32), 68, kUpb_NoSub, 12, (int)kUpb_FieldMode_Scalar | ((int)kUpb_FieldRep_StringView << kUpb_FieldRep_Shift)},
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#ifdef UPB_TRACING_ENABLED
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const upb_MiniTable google__protobuf__SourceCodeInfo__Location_msg_init = {
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const upb_MiniTableEnum google__protobuf__FeatureSet__FieldPresence_enum_init = {
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const upb_MiniTableEnum google__protobuf__FeatureSet__VisibilityFeature__DefaultSymbolVisibility_enum_init = {
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#include <errno.h>
#include <float.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>

// Must be last.

void upb_Status_Clear(upb_Status* status) {
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}

bool upb_Status_IsOk(const upb_Status* status) { return status->ok; }

const char* upb_Status_ErrorMessage(const upb_Status* status) {
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}

void upb_Status_SetErrorMessage(upb_Status* status, const char* msg) {
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void upb_Status_SetErrorFormat(upb_Status* status, const char* fmt, ...) {
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void upb_Status_VSetErrorFormat(upb_Status* status, const char* fmt,
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}

void upb_Status_VAppendErrorFormat(upb_Status* status, const char* fmt,
                                   va_list args) {
  size_t len;
  if (!status) return;
  status->ok = false;
  len = strlen(status->msg);
  vsnprintf(status->msg + len, sizeof(status->msg) - len, fmt, args);
  status->msg[_kUpb_Status_MaxMessage - 1] = '\0';
}

/*
 * upb_table Implementation
 *
 * Implementation is heavily inspired by Lua's ltable.c.
 */


#include <stdint.h>
#include <string.h>


// Must be last.

#define UPB_MAXARRSIZE 16  // 2**16 = 64k.

// From Chromium.
#define ARRAY_SIZE(x) \
  ((sizeof(x) / sizeof(0 [x])) / ((size_t)(!(sizeof(x) % sizeof(0 [x])))))

/* The minimum utilization of the array part of a mixed hash/array table.  This
 * is a speed/memory-usage tradeoff (though it's not straightforward because of
 * cache effects).  The lower this is, the more memory we'll use. */
static const double MIN_DENSITY = 0.1;

#if defined(__has_builtin)
#if __has_builtin(__builtin_popcount)
#define UPB_FAST_POPCOUNT32(i) __builtin_popcount(i)
#endif
#elif defined(__GNUC__)
#define UPB_FAST_POPCOUNT32(i) __builtin_popcount(i)
#elif defined(_MSC_VER) && (defined(_M_IX86) || defined(_M_X64))
// Only use __popcnt on x86/x64 architectures for MSVC
#define UPB_FAST_POPCOUNT32(i) __popcnt(i)
#endif

UPB_INLINE int _upb_popcnt32(uint32_t i) {
#ifdef UPB_FAST_POPCOUNT32
  return UPB_FAST_POPCOUNT32(i);
#else
  int count = 0;
  while (i != 0) {
    count += i & 1;
    i >>= 1;
  }
  return count;
#endif
}

#undef UPB_FAST_POPCOUNT32

UPB_INLINE uint8_t _upb_log2_table_size(upb_table* t) {
  return _upb_popcnt32(t->mask);
}

static bool is_pow2(uint64_t v) { return v == 0 || (v & (v - 1)) == 0; }

static int log2ceil(uint64_t v) {
  int ret = 0;
  bool pow2 = is_pow2(v);
  while (v >>= 1) ret++;
  ret = pow2 ? ret : ret + 1;  // Ceiling.
  return UPB_MIN(UPB_MAXARRSIZE, ret);
}

/* A type to represent the lookup key of either a strtable, inttable or
 * exttable. */
typedef union {
  uintptr_t num;
  upb_StringView str;
  struct {
    const void* ptr;
    uint32_t ext_num;
  } ext;
} lookupkey_t;

static lookupkey_t strkey2(const char* str, size_t len) {
  return (lookupkey_t){.str = upb_StringView_FromDataAndSize(str, len)};
}

static lookupkey_t intkey(uintptr_t key) { return (lookupkey_t){.num = key}; }

static lookupkey_t extkey(const void* ptr, uint32_t ext_num) {
  return (lookupkey_t){.ext = {ptr, ext_num}};
}

// Conceptually the hash and equal functions should only take the key, not the
// value, but the extension table stores part of its logical key in the value
// slot. This is a sign that we have outgrown the original architecture.
typedef uint32_t hashfunc_t(upb_key key, upb_value val);
typedef bool eqlfunc_t(upb_key k1, upb_value v1, lookupkey_t k2);

/* Base table (shared code) ***************************************************/

static uint32_t upb_inthash(uintptr_t key) {
  UPB_STATIC_ASSERT(sizeof(uintptr_t) == 4 || sizeof(uintptr_t) == 8,
                    "Pointers don't fit");
  if (sizeof(uintptr_t) == 8) {
    return (uint32_t)key ^ (uint32_t)(key >> 32);
  } else {
    return (uint32_t)key;
  }
}

static const upb_tabent* upb_getentry(const upb_table* t, uint32_t hash) {
  return t->entries + (hash & t->mask);
}

static bool isfull(upb_table* t) {
  uint32_t size = upb_table_size(t);
  // 0.875 load factor
  return t->count == (size - (size >> 3));
}

static bool init(upb_table* t, uint8_t size_lg2, upb_Arena* a) {
  if (size_lg2 >= 32) {
    return false;
  }
  t->count = 0;
  uint32_t size = 1 << size_lg2;
  t->mask = size - 1;  // 0 mask if size_lg2 is 0
  if (upb_table_size(t) > (SIZE_MAX / sizeof(upb_tabent))) {
    return false;
  }
  size_t bytes = upb_table_size(t) * sizeof(upb_tabent);
  if (bytes > 0) {
    t->entries = upb_Arena_Malloc(a, bytes);
    if (!t->entries) return false;
    memset(t->entries, 0, bytes);
  } else {
    t->entries = NULL;
  }
  return true;
}

static upb_tabent* emptyent(upb_table* t, upb_tabent* e) {
  upb_tabent* begin = t->entries;
  upb_tabent* end = begin + upb_table_size(t);
  for (e = e + 1; e < end; e++) {
    if (upb_tabent_isempty(e)) return e;
  }
  for (e = begin; e < end; e++) {
    if (upb_tabent_isempty(e)) return e;
  }
  UPB_ASSERT(false);
  return NULL;
}

static upb_tabent* getentry_mutable(upb_table* t, uint32_t hash) {
  return (upb_tabent*)upb_getentry(t, hash);
}

static const upb_tabent* findentry(const upb_table* t, lookupkey_t key,
                                   uint32_t hash, eqlfunc_t* eql) {
  const upb_tabent* e;

  if (t->count == 0) return NULL;
  e = upb_getentry(t, hash);
  if (upb_tabent_isempty(e)) return NULL;
  while (1) {
    if (eql(e->key, e->val, key)) return e;
    if ((e = e->next) == NULL) return NULL;
  }
}

static upb_tabent* findentry_mutable(upb_table* t, lookupkey_t key,
                                     uint32_t hash, eqlfunc_t* eql) {
  return (upb_tabent*)findentry(t, key, hash, eql);
}

static bool lookup(const upb_table* t, lookupkey_t key, upb_value* v,
                   uint32_t hash, eqlfunc_t* eql) {
  const upb_tabent* e = findentry(t, key, hash, eql);
  if (e) {
    if (v) *v = e->val;
    return true;
  } else {
    return false;
  }
}

/* The given key must not already exist in the table. */
static void insert(upb_table* t, lookupkey_t key, upb_key tabkey, upb_value val,
                   uint32_t hash, hashfunc_t* hashfunc, eqlfunc_t* eql) {
  upb_tabent* mainpos_e;
  upb_tabent* our_e;

  UPB_ASSERT(findentry(t, key, hash, eql) == NULL);

  t->count++;
  mainpos_e = getentry_mutable(t, hash);
  our_e = mainpos_e;

  if (upb_tabent_isempty(mainpos_e)) {
    /* Our main position is empty; use it. */
    our_e->next = NULL;
  } else {
    /* Collision. */
    upb_tabent* new_e = emptyent(t, mainpos_e);
    /* Head of collider's chain. */
    upb_tabent* chain =
        getentry_mutable(t, hashfunc(mainpos_e->key, mainpos_e->val));
    if (chain == mainpos_e) {
      /* Existing ent is in its main position (it has the same hash as us, and
       * is the head of our chain).  Insert to new ent and append to this chain.
       */
      new_e->next = mainpos_e->next;
      mainpos_e->next = new_e;
      our_e = new_e;
    } else {
      /* Existing ent is not in its main position (it is a node in some other
       * chain).  This implies that no existing ent in the table has our hash.
       * Evict it (updating its chain) and use its ent for head of our chain. */
      *new_e = *mainpos_e; /* copies next. */
      while (chain->next != mainpos_e) {
        chain = (upb_tabent*)chain->next;
        UPB_ASSERT(chain);
      }
      chain->next = new_e;
      our_e = mainpos_e;
      our_e->next = NULL;
    }
  }
  our_e->key = tabkey;
  our_e->val = val;
  UPB_ASSERT(findentry(t, key, hash, eql) == our_e);
}

static bool rm(upb_table* t, lookupkey_t key, upb_value* val, uint32_t hash,
               eqlfunc_t* eql) {
  upb_tabent* chain = getentry_mutable(t, hash);
  if (upb_tabent_isempty(chain)) return false;
  if (eql(chain->key, chain->val, key)) {
    /* Element to remove is at the head of its chain. */
    t->count--;
    if (val) *val = chain->val;
    if (chain->next) {
      upb_tabent* move = (upb_tabent*)chain->next;
      *chain = *move;
      move->key = upb_key_empty();
    } else {
      chain->key = upb_key_empty();
    }
    return true;
  } else {
    /* Element to remove is either in a non-head position or not in the
     * table. */
    while (chain->next && !eql(chain->next->key, chain->next->val, key)) {
      chain = (upb_tabent*)chain->next;
    }
    if (chain->next) {
      /* Found element to remove. */
      upb_tabent* rm = (upb_tabent*)chain->next;
      t->count--;
      if (val) *val = chain->next->val;
      rm->key = upb_key_empty();
      chain->next = rm->next;
      return true;
    } else {
      /* Element to remove is not in the table. */
      return false;
    }
  }
}

static size_t next(const upb_table* t, size_t i) {
  do {
    if (++i >= upb_table_size(t)) return SIZE_MAX - 1; /* Distinct from -1. */
  } while (upb_tabent_isempty(&t->entries[i]));

  return i;
}

static size_t begin(const upb_table* t) { return next(t, -1); }

/* upb_strtable ***************************************************************/

// A simple "subclass" of upb_table that only adds a hash function for strings.

static upb_SizePrefixString* upb_SizePrefixString_Copy(upb_StringView s,
                                                       upb_Arena* a) {
  // A 2GB string will fail at serialization time, but we accept up to 4GB in
  // memory here.
  if (s.size > UINT32_MAX) return NULL;
  upb_SizePrefixString* str =
      upb_Arena_Malloc(a, sizeof(uint32_t) + s.size + 1);
  if (str == NULL) return NULL;
  str->size = s.size;
  char* data = (char*)str->data;
  if (s.size) memcpy(data, s.data, s.size);
  data[s.size] = '\0';
  return str;
}

/* Adapted from ABSL's wyhash. */

static uint64_t UnalignedLoad64(const void* p) {
  uint64_t val;
  memcpy(&val, p, 8);
  return val;
}

static uint32_t UnalignedLoad32(const void* p) {
  uint32_t val;
  memcpy(&val, p, 4);
  return val;
}

#if defined(_MSC_VER) && defined(_M_X64)
#include <intrin.h>
#endif

/* Computes a * b, returning the low 64 bits of the result and storing the high
 * 64 bits in |*high|. */
static uint64_t upb_umul128(uint64_t v0, uint64_t v1, uint64_t* out_high) {
#ifdef __SIZEOF_INT128__
  __uint128_t p = v0;
  p *= v1;
  *out_high = (uint64_t)(p >> 64);
  return (uint64_t)p;
#elif defined(_MSC_VER) && defined(_M_X64)
  return _umul128(v0, v1, out_high);
#else
  uint64_t a32 = v0 >> 32;
  uint64_t a00 = v0 & 0xffffffff;
  uint64_t b32 = v1 >> 32;
  uint64_t b00 = v1 & 0xffffffff;
  uint64_t high = a32 * b32;
  uint64_t low = a00 * b00;
  uint64_t mid1 = a32 * b00;
  uint64_t mid2 = a00 * b32;
  low += (mid1 << 32) + (mid2 << 32);
  // Omit carry bit, for mixing we do not care about exact numerical precision.
  high += (mid1 >> 32) + (mid2 >> 32);
  *out_high = high;
  return low;
#endif
}

static uint64_t WyhashMix(uint64_t v0, uint64_t v1) {
  uint64_t high;
  uint64_t low = upb_umul128(v0, v1, &high);
  return low ^ high;
}

static uint64_t Wyhash(const void* data, size_t len, uint64_t seed,
                       const uint64_t salt[]) {
  const uint8_t* ptr = (const uint8_t*)data;
  uint64_t starting_length = (uint64_t)len;
  uint64_t current_state = seed ^ salt[0];

  if (len > 64) {
    // If we have more than 64 bytes, we're going to handle chunks of 64
    // bytes at a time. We're going to build up two separate hash states
    // which we will then hash together.
    uint64_t duplicated_state = current_state;

    do {
      uint64_t a = UnalignedLoad64(ptr);
      uint64_t b = UnalignedLoad64(ptr + 8);
      uint64_t c = UnalignedLoad64(ptr + 16);
      uint64_t d = UnalignedLoad64(ptr + 24);
      uint64_t e = UnalignedLoad64(ptr + 32);
      uint64_t f = UnalignedLoad64(ptr + 40);
      uint64_t g = UnalignedLoad64(ptr + 48);
      uint64_t h = UnalignedLoad64(ptr + 56);

      uint64_t cs0 = WyhashMix(a ^ salt[1], b ^ current_state);
      uint64_t cs1 = WyhashMix(c ^ salt[2], d ^ current_state);
      current_state = (cs0 ^ cs1);

      uint64_t ds0 = WyhashMix(e ^ salt[3], f ^ duplicated_state);
      uint64_t ds1 = WyhashMix(g ^ salt[4], h ^ duplicated_state);
      duplicated_state = (ds0 ^ ds1);

      ptr += 64;
      len -= 64;
    } while (len > 64);

    current_state = current_state ^ duplicated_state;
  }

  // We now have a data `ptr` with at most 64 bytes and the current state
  // of the hashing state machine stored in current_state.
  while (len > 16) {
    uint64_t a = UnalignedLoad64(ptr);
    uint64_t b = UnalignedLoad64(ptr + 8);

    current_state = WyhashMix(a ^ salt[1], b ^ current_state);

    ptr += 16;
    len -= 16;
  }

  // We now have a data `ptr` with at most 16 bytes.
  uint64_t a = 0;
  uint64_t b = 0;
  if (len > 8) {
    // When we have at least 9 and at most 16 bytes, set A to the first 64
    // bits of the input and B to the last 64 bits of the input. Yes, they will
    // overlap in the middle if we are working with less than the full 16
    // bytes.
    a = UnalignedLoad64(ptr);
    b = UnalignedLoad64(ptr + len - 8);
  } else if (len > 3) {
    // If we have at least 4 and at most 8 bytes, set A to the first 32
    // bits and B to the last 32 bits.
    a = UnalignedLoad32(ptr);
    b = UnalignedLoad32(ptr + len - 4);
  } else if (len > 0) {
    // If we have at least 1 and at most 3 bytes, read all of the provided
    // bits into A, with some adjustments.
    a = ((ptr[0] << 16) | (ptr[len >> 1] << 8) | ptr[len - 1]);
    b = 0;
  } else {
    a = 0;
    b = 0;
  }

  uint64_t w = WyhashMix(a ^ salt[1], b ^ current_state);
  uint64_t z = salt[1] ^ starting_length;
  return WyhashMix(w, z);
}

const uint64_t kWyhashSalt[5] = {
    0x243F6A8885A308D3ULL, 0x13198A2E03707344ULL, 0xA4093822299F31D0ULL,
    0x082EFA98EC4E6C89ULL, 0x452821E638D01377ULL,
};

uint32_t _upb_Hash(const void* p, size_t n, uint64_t seed) {
  return Wyhash(p, n, seed, kWyhashSalt);
}

static const void* const _upb_seed;

// Returns a random seed for upb's hash function. This does not provide
// high-quality randomness, but it should be enough to prevent unit tests from
// relying on a deterministic map ordering. By returning the address of a
// variable, we are able to get some randomness for free provided that ASLR is
// enabled.
static uint64_t _upb_Seed(void) { return (uint64_t)&_upb_seed; }

static uint32_t _upb_Hash_NoSeed(const char* p, size_t n) {
  return _upb_Hash(p, n, _upb_Seed());
}

static uint32_t strhash(upb_key key, upb_value val) {
  UPB_UNUSED(val);
  return _upb_Hash_NoSeed(key.str->data, key.str->size);
}

static bool streql(upb_key k1, upb_value v1, lookupkey_t k2) {
  UPB_UNUSED(v1);
  const upb_SizePrefixString* k1s = k1.str;
  const upb_StringView k2s = k2.str;
  return k1s->size == k2s.size &&
         (k1s->size == 0 || memcmp(k1s->data, k2s.data, k1s->size) == 0);
}

/** Calculates the number of entries required to hold an expected number of
 * values, within the table's load factor. */
static size_t _upb_entries_needed_for(size_t expected_size) {
  size_t need_entries = expected_size + 1 + expected_size / 7;
  UPB_ASSERT(need_entries - (need_entries >> 3) >= expected_size);
  return need_entries;
}

bool upb_strtable_init(upb_strtable* t, size_t expected_size, upb_Arena* a) {
  int size_lg2 = upb_Log2Ceiling(_upb_entries_needed_for(expected_size));
  return init(&t->t, size_lg2, a);
}

void upb_strtable_clear(upb_strtable* t) {
  size_t bytes = upb_table_size(&t->t) * sizeof(upb_tabent);
  t->t.count = 0;
  memset((char*)t->t.entries, 0, bytes);
}

bool upb_strtable_resize(upb_strtable* t, size_t size_lg2, upb_Arena* a) {
  upb_strtable new_table;
  if (!init(&new_table.t, size_lg2, a)) return false;

  intptr_t iter = UPB_STRTABLE_BEGIN;
  upb_StringView sv;
  upb_value val;
  while (upb_strtable_next2(t, &sv, &val, &iter)) {
    // Unlike normal insert, does not copy string data or possibly reallocate
    // the table
    // The data pointer used in the table is guaranteed to point at a
    // upb_SizePrefixString, we just need to back up by the size of the uint32_t
    // length prefix.
    const upb_SizePrefixString* keystr =
        (const upb_SizePrefixString*)(sv.data - sizeof(uint32_t));
    UPB_ASSERT(keystr->data == sv.data);
    UPB_ASSERT(keystr->size == sv.size);

    lookupkey_t lookupkey = {.str = sv};
    upb_key tabkey = {.str = keystr};
    uint32_t hash = _upb_Hash_NoSeed(sv.data, sv.size);
    insert(&new_table.t, lookupkey, tabkey, val, hash, &strhash, &streql);
  }
  *t = new_table;
  return true;
}

bool upb_strtable_insert(upb_strtable* t, const char* k, size_t len,
                         upb_value v, upb_Arena* a) {
  if (isfull(&t->t)) {
    /* Need to resize.  New table of double the size, add old elements to it. */
    if (!upb_strtable_resize(t, _upb_log2_table_size(&t->t) + 1, a)) {
      return false;
    }
  }

  upb_StringView sv = upb_StringView_FromDataAndSize(k, len);
  upb_SizePrefixString* size_prefix_string = upb_SizePrefixString_Copy(sv, a);
  if (!size_prefix_string) return false;

  lookupkey_t lookupkey = {.str = sv};
  upb_key key = {.str = size_prefix_string};
  uint32_t hash = _upb_Hash_NoSeed(k, len);
  insert(&t->t, lookupkey, key, v, hash, &strhash, &streql);
  return true;
}

bool upb_strtable_lookup2(const upb_strtable* t, const char* key, size_t len,
                          upb_value* v) {
  uint32_t hash = _upb_Hash_NoSeed(key, len);
  return lookup(&t->t, strkey2(key, len), v, hash, &streql);
}

bool upb_strtable_remove2(upb_strtable* t, const char* key, size_t len,
                          upb_value* val) {
  uint32_t hash = _upb_Hash_NoSeed(key, len);
  return rm(&t->t, strkey2(key, len), val, hash, &streql);
}

/* Iteration */

void upb_strtable_begin(upb_strtable_iter* i, const upb_strtable* t) {
  i->t = t;
  i->index = begin(&t->t);
}

void upb_strtable_next(upb_strtable_iter* i) {
  i->index = next(&i->t->t, i->index);
}

bool upb_strtable_done(const upb_strtable_iter* i) {
  if (!i->t) return true;
  return i->index >= upb_table_size(&i->t->t) ||
         upb_tabent_isempty(str_tabent(i));
}

upb_StringView upb_strtable_iter_key(const upb_strtable_iter* i) {
  UPB_ASSERT(!upb_strtable_done(i));
  return upb_key_strview(str_tabent(i)->key);
}

upb_value upb_strtable_iter_value(const upb_strtable_iter* i) {
  UPB_ASSERT(!upb_strtable_done(i));
  return str_tabent(i)->val;
}

void upb_strtable_iter_setdone(upb_strtable_iter* i) {
  i->t = NULL;
  i->index = SIZE_MAX;
}

bool upb_strtable_iter_isequal(const upb_strtable_iter* i1,
                               const upb_strtable_iter* i2) {
  if (upb_strtable_done(i1) && upb_strtable_done(i2)) return true;
  return i1->t == i2->t && i1->index == i2->index;
}

bool upb_strtable_next2(const upb_strtable* t, upb_StringView* key,
                        upb_value* val, intptr_t* iter) {
  size_t tab_idx = next(&t->t, *iter);
  if (tab_idx < upb_table_size(&t->t)) {
    upb_tabent* ent = &t->t.entries[tab_idx];
    *key = upb_key_strview(ent->key);
    *val = ent->val;
    *iter = tab_idx;
    return true;
  }

  return false;
}

void upb_strtable_removeiter(upb_strtable* t, intptr_t* iter) {
  intptr_t i = *iter;
  upb_tabent* ent = &t->t.entries[i];
  upb_tabent* prev = NULL;

  // Linear search, not great.
  upb_tabent* end = &t->t.entries[upb_table_size(&t->t)];
  for (upb_tabent* e = t->t.entries; e != end; e++) {
    if (e->next == ent) {
      prev = e;
      break;
    }
  }

  if (prev) {
    prev->next = ent->next;
  }

  t->t.count--;
  ent->key = upb_key_empty();
  ent->next = NULL;
}

void upb_strtable_setentryvalue(upb_strtable* t, intptr_t iter, upb_value v) {
  t->t.entries[iter].val = v;
}

/* upb_exttable ***************************************************************/

static uint32_t _upb_exttable_hash(const void* ptr, uint32_t ext_num) {
  uint64_t a = (uintptr_t)ptr;
  uint64_t b = ext_num;
  return (uint32_t)WyhashMix(a ^ kWyhashSalt[1], b ^ _upb_Seed());
}

static uint32_t exthash(upb_key key, upb_value val) {
  const void* ptr = (const void*)key.num;
  uint32_t ext_num = *(const uint32_t*)upb_value_getconstptr(val);
  return _upb_exttable_hash(ptr, ext_num);
}

static bool exteql(upb_key k1, upb_value v1, lookupkey_t k2) {
  if ((const void*)k1.num == k2.ext.ptr) {
    uint32_t ext_num1 = *(const uint32_t*)upb_value_getconstptr(v1);
    return ext_num1 == k2.ext.ext_num;
  }
  return false;
}

bool upb_exttable_init(upb_exttable* t, size_t expected_size, upb_Arena* a) {
  int size_lg2 = upb_Log2Ceiling(_upb_entries_needed_for(expected_size));
  return init(&t->t, size_lg2, a);
}

void upb_exttable_clear(upb_exttable* t) {
  size_t bytes = upb_table_size(&t->t) * sizeof(upb_tabent);
  t->t.count = 0;
  memset((char*)t->t.entries, 0, bytes);
}

bool upb_exttable_resize(upb_exttable* t, size_t size_lg2, upb_Arena* a) {
  upb_exttable new_table;
  if (!init(&new_table.t, size_lg2, a)) return false;

  size_t i;
  for (i = begin(&t->t); i < upb_table_size(&t->t); i = next(&t->t, i)) {
    const upb_tabent* e = &t->t.entries[i];
    uint32_t hash = exthash(e->key, e->val);
    uint32_t ext_num = *(const uint32_t*)upb_value_getconstptr(e->val);
    lookupkey_t lookupkey = extkey((const void*)e->key.num, ext_num);
    insert(&new_table.t, lookupkey, e->key, e->val, hash, &exthash, &exteql);
  }

  *t = new_table;
  return true;
}

bool upb_exttable_insert(upb_exttable* t, const void* k, const uint32_t* v,
                         upb_Arena* a) {
  UPB_ASSERT(k != NULL);
  UPB_ASSERT(v != NULL);
  UPB_ASSERT(*v != 0);

  if (isfull(&t->t)) {
    if (!upb_exttable_resize(t, _upb_log2_table_size(&t->t) + 1, a)) {
      return false;
    }
  }

  lookupkey_t lookupkey = extkey(k, *v);
  upb_key key = {.num = (uintptr_t)k};
  upb_value val = upb_value_constptr(v);
  uint32_t hash = _upb_exttable_hash(k, *v);
  insert(&t->t, lookupkey, key, val, hash, &exthash, &exteql);
  return true;
}

const uint32_t* upb_exttable_lookup(const upb_exttable* t, const void* k,
                                    uint32_t ext_number) {
  uint32_t hash = _upb_exttable_hash(k, ext_number);
  upb_value val;
  if (lookup(&t->t, extkey(k, ext_number), &val, hash, &exteql)) {
    return (const uint32_t*)upb_value_getconstptr(val);
  }
  return NULL;
}

const uint32_t* upb_exttable_remove(upb_exttable* t, const void* k,
                                    uint32_t ext_number) {
  uint32_t hash = _upb_exttable_hash(k, ext_number);
  upb_value val;
  if (rm(&t->t, extkey(k, ext_number), &val, hash, &exteql)) {
    return (const uint32_t*)upb_value_getconstptr(val);
  }
  return NULL;
}

size_t upb_exttable_size(const upb_exttable* t) { return t->t.count; }

/* upb_inttable ***************************************************************/

/* For inttables we use a hybrid structure where small keys are kept in an
 * array and large keys are put in the hash table. */

// The sentinel value used in the dense array part. Note that callers must
// ensure that inttable is never used with a value of this sentinel type
// (pointers and u32 values will never be; i32 needs to be handled carefully
// to avoid sign-extending into this value).
static const upb_value kInttableSentinel = {.val = UINT64_MAX};
static uint32_t presence_mask_arr_size(uint32_t array_size) {
  return (array_size + 7) / 8;  // sizeof(uint8_t) is always 1.
}

static uint32_t inthash(upb_key key, upb_value val) {
  UPB_UNUSED(val);
  return upb_inthash(key.num);
}

static bool inteql(upb_key k1, upb_value v1, lookupkey_t k2) {
  UPB_UNUSED(v1);
  return k1.num == k2.num;
}

static upb_value* mutable_array(upb_inttable* t) {
  return (upb_value*)t->array;
}

static const upb_value* inttable_array_get(const upb_inttable* t,
                                           uintptr_t key) {
  UPB_ASSERT(key < t->array_size);
  const upb_value* val = &t->array[key];
  return upb_inttable_arrhas(t, key) ? val : NULL;
}

static upb_value* inttable_val(upb_inttable* t, uintptr_t key) {
  if (key < t->array_size) {
    return (upb_value*)inttable_array_get(t, key);
  } else {
    upb_tabent* e =
        findentry_mutable(&t->t, intkey(key), upb_inthash(key), &inteql);
    return e ? &e->val : NULL;
  }
}

static const upb_value* inttable_val_const(const upb_inttable* t,
                                           uintptr_t key) {
  return inttable_val((upb_inttable*)t, key);
}

size_t upb_inttable_count(const upb_inttable* t) {
  return t->t.count + t->array_count;
}

static void check(upb_inttable* t) {
  UPB_UNUSED(t);
#if defined(UPB_DEBUG_TABLE) && !defined(NDEBUG)
  {
    // This check is very expensive (makes inserts/deletes O(N)).
    size_t count = 0;
    intptr_t iter = UPB_INTTABLE_BEGIN;
    uintptr_t key;
    upb_value val;
    while (upb_inttable_next(t, &key, &val, &iter)) {
      UPB_ASSERT(upb_inttable_lookup(t, key, NULL));
    }
    UPB_ASSERT(count == upb_inttable_count(t));
  }
#endif
}

bool upb_inttable_sizedinit(upb_inttable* t, uint32_t asize, int hsize_lg2,
                            upb_Arena* a) {
  if (!init(&t->t, hsize_lg2, a)) return false;
  /* Always make the array part at least 1 long, so that we know key 0
   * won't be in the hash part, which simplifies things. */
  t->array_size = UPB_MAX(1, asize);
  t->array_count = 0;
#if UINT32_MAX >= SIZE_MAX
  if (UPB_UNLIKELY(SIZE_MAX / sizeof(upb_value) < t->array_size)) {
    return false;
  }
#endif

  // Allocate the array part and the presence mask array in one allocation.
  size_t array_bytes = t->array_size * sizeof(upb_value);
  uint32_t presence_bytes = presence_mask_arr_size(t->array_size);
  uintptr_t total_bytes = array_bytes + presence_bytes;
  if (UPB_UNLIKELY(total_bytes > SIZE_MAX)) {
    return false;
  }
  void* alloc = upb_Arena_Malloc(a, total_bytes);
  if (!alloc) {
    return false;
  }
  t->array = alloc;
  memset(mutable_array(t), 0xff, array_bytes);
  t->presence_mask = (uint8_t*)alloc + array_bytes;
  memset((uint8_t*)t->presence_mask, 0, presence_bytes);

  check(t);
  return true;
}

bool upb_inttable_init(upb_inttable* t, upb_Arena* a) {
  // The init size of the table part to match that of strtable.
  return upb_inttable_sizedinit(t, 0, 3, a);
}

bool upb_inttable_insert(upb_inttable* t, uintptr_t key, upb_value val,
                         upb_Arena* a) {
  if (key < t->array_size) {
    UPB_ASSERT(!upb_inttable_arrhas(t, key));
    t->array_count++;
    mutable_array(t)[key] = val;
    ((uint8_t*)t->presence_mask)[key / 8] |= (1 << (key % 8));
  } else {
    if (isfull(&t->t)) {
      /* Need to resize the hash part, but we re-use the array part. */
      size_t i;
      upb_table new_table;

      if (!init(&new_table, _upb_log2_table_size(&t->t) + 1, a)) {
        return false;
      }

      for (i = begin(&t->t); i < upb_table_size(&t->t); i = next(&t->t, i)) {
        const upb_tabent* e = &t->t.entries[i];
        insert(&new_table, intkey(e->key.num), e->key, e->val,
               inthash(e->key, e->val), &inthash, &inteql);
      }

      UPB_ASSERT(t->t.count == new_table.count);

      t->t = new_table;
    }
    upb_key tabkey = {.num = key};
    insert(&t->t, intkey(key), tabkey, val, upb_inthash(key), &inthash,
           &inteql);
  }
  check(t);
  return true;
}

bool upb_inttable_lookup(const upb_inttable* t, uintptr_t key, upb_value* v) {
  const upb_value* table_v = inttable_val_const(t, key);
  if (!table_v) return false;
  if (v) *v = *table_v;
  return true;
}

bool upb_inttable_replace(upb_inttable* t, uintptr_t key, upb_value val) {
  upb_value* table_v = inttable_val(t, key);
  if (!table_v) return false;
  *table_v = val;
  return true;
}

bool upb_inttable_remove(upb_inttable* t, uintptr_t key, upb_value* val) {
  bool success;
  if (key < t->array_size) {
    if (upb_inttable_arrhas(t, key)) {
      t->array_count--;
      if (val) {
        *val = t->array[key];
      }
      mutable_array(t)[key] = kInttableSentinel;
      ((uint8_t*)t->presence_mask)[key / 8] &= ~(1 << (key % 8));
      success = true;
    } else {
      success = false;
    }
  } else {
    success = rm(&t->t, intkey(key), val, upb_inthash(key), &inteql);
  }
  check(t);
  return success;
}

bool upb_inttable_compact(upb_inttable* t, upb_Arena* a) {
  /* A power-of-two histogram of the table keys. */
  uint32_t counts[UPB_MAXARRSIZE + 1] = {0};

  /* The max key in each bucket. */
  uintptr_t max[UPB_MAXARRSIZE + 1] = {0};

  {
    intptr_t iter = UPB_INTTABLE_BEGIN;
    uintptr_t key;
    upb_value val;
    while (upb_inttable_next(t, &key, &val, &iter)) {
      int bucket = log2ceil(key);
      max[bucket] = UPB_MAX(max[bucket], key);
      counts[bucket]++;
    }
  }

  /* Find the largest power of two that satisfies the MIN_DENSITY
   * definition (while actually having some keys). */
  uint32_t arr_count = upb_inttable_count(t);

  // Scan all buckets except capped bucket
  int size_lg2 = ARRAY_SIZE(counts) - 1;
  for (; size_lg2 > 0; size_lg2--) {
    if (counts[size_lg2] == 0) {
      /* We can halve again without losing any entries. */
      continue;
    } else if (arr_count >= (1 << size_lg2) * MIN_DENSITY) {
      break;
    }

    arr_count -= counts[size_lg2];
  }

  UPB_ASSERT(arr_count <= upb_inttable_count(t));

  upb_inttable new_t;
  {
    /* Insert all elements into new, perfectly-sized table. */
    uintptr_t arr_size = max[size_lg2] + 1; /* +1 so arr[max] will fit. */
    uint32_t hash_count = upb_inttable_count(t) - arr_count;
    size_t hash_size = hash_count ? _upb_entries_needed_for(hash_count) : 0;
    int hashsize_lg2 = log2ceil(hash_size);

    if (!upb_inttable_sizedinit(&new_t, arr_size, hashsize_lg2, a)) {
      return false;
    }

    {
      intptr_t iter = UPB_INTTABLE_BEGIN;
      uintptr_t key;
      upb_value val;
      while (upb_inttable_next(t, &key, &val, &iter)) {
        upb_inttable_insert(&new_t, key, val, a);
      }
    }

    UPB_ASSERT(new_t.array_size == arr_size);
  }
  *t = new_t;
  return true;
}

void upb_inttable_clear(upb_inttable* t) {
  // Clear the array part.
  size_t array_bytes = t->array_size * sizeof(upb_value);
  t->array_count = 0;
  // Clear the array by setting all bits to 1, as UINT64_MAX is the sentinel
  // value for an empty array.
  memset(mutable_array(t), 0xff, array_bytes);
  // Clear the presence mask array.
  memset((uint8_t*)t->presence_mask, 0, presence_mask_arr_size(t->array_size));
  // Clear the table part.
  size_t bytes = upb_table_size(&t->t) * sizeof(upb_tabent);
  t->t.count = 0;
  memset((char*)t->t.entries, 0, bytes);
}

// Iteration.

bool upb_inttable_next(const upb_inttable* t, uintptr_t* key, upb_value* val,
                       intptr_t* iter) {
  intptr_t i = *iter;
  if ((size_t)(i + 1) <= t->array_size) {
    while ((size_t)++i < t->array_size) {
      const upb_value* ent = inttable_array_get(t, i);
      if (ent) {
        *key = i;
        *val = *ent;
        *iter = i;
        return true;
      }
    }
    i--;  // Back up to exactly one position before the start of the table.
  }

  size_t tab_idx = next(&t->t, i - t->array_size);
  if (tab_idx < upb_table_size(&t->t)) {
    upb_tabent* ent = &t->t.entries[tab_idx];
    *key = ent->key.num;
    *val = ent->val;
    *iter = tab_idx + t->array_size;
    return true;
  } else {
    // We should set the iterator any way. When we are done, the iterator value
    // is invalidated. `upb_inttable_done` will check on the iterator value to
    // determine if the iteration is done.
    *iter = INTPTR_MAX - 1;  // To disambiguate from UPB_INTTABLE_BEGIN, to
                             // match the behavior of `upb_strtable_iter`.
    return false;
  }
}

void upb_inttable_removeiter(upb_inttable* t, intptr_t* iter) {
  intptr_t i = *iter;
  if ((size_t)i < t->array_size) {
    t->array_count--;
    mutable_array(t)[i].val = -1;
  } else {
    upb_tabent* ent = &t->t.entries[i - t->array_size];
    upb_tabent* prev = NULL;

    // Linear search, not great.
    upb_tabent* end = &t->t.entries[upb_table_size(&t->t)];
    for (upb_tabent* e = t->t.entries; e != end; e++) {
      if (e->next == ent) {
        prev = e;
        break;
      }
    }

    if (prev) {
      prev->next = ent->next;
    }

    t->t.count--;
    ent->key = upb_key_empty();
    ent->next = NULL;
  }
}

void upb_inttable_setentryvalue(upb_inttable* t, intptr_t iter, upb_value v) {
  if ((size_t)iter < t->array_size) {
    mutable_array(t)[iter] = v;
  } else {
    upb_tabent* ent = &t->t.entries[iter - t->array_size];
    ent->val = v;
  }
}

bool upb_inttable_done(const upb_inttable* t, intptr_t iter) {
  if ((uintptr_t)iter >= t->array_size + upb_table_size(&t->t)) {
    return true;
  } else if ((size_t)iter < t->array_size) {
    return !upb_inttable_arrhas(t, iter);
  } else {
    return upb_tabent_isempty(&t->t.entries[iter - t->array_size]);
  }
}

uintptr_t upb_inttable_iter_key(const upb_inttable* t, intptr_t iter) {
  UPB_ASSERT(!upb_inttable_done(t, iter));
  return (size_t)iter < t->array_size
             ? iter
             : t->t.entries[iter - t->array_size].key.num;
}

upb_value upb_inttable_iter_value(const upb_inttable* t, intptr_t iter) {
  UPB_ASSERT(!upb_inttable_done(t, iter));
  if ((size_t)iter < t->array_size) {
    return t->array[iter];
  } else {
    return t->t.entries[iter - t->array_size].val;
  }
}


#include <errno.h>
#include <float.h>
#include <inttypes.h>
#include <limits.h>
#include <math.h>
#include <setjmp.h>
#include <stdarg.h>
#include <stddef.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>


// Must be last.

typedef struct {
  const char *ptr, *end;
  upb_Arena* arena; /* TODO: should we have a tmp arena for tmp data? */
  const upb_DefPool* symtab;
  int depth;
  int result;
  upb_Status* status;
  jmp_buf err;
  int line;
  const char* line_begin;
  bool is_first;
  int options;
  const upb_FieldDef* debug_field;
} jsondec;

typedef struct {
  upb_MessageValue value;
  bool ignore;
} upb_JsonMessageValue;

enum { JD_OBJECT, JD_ARRAY, JD_STRING, JD_NUMBER, JD_TRUE, JD_FALSE, JD_NULL };

/* Forward declarations of mutually-recursive functions. */
static void jsondec_wellknown(jsondec* d, upb_Message* msg,
                              const upb_MessageDef* m);
static upb_JsonMessageValue jsondec_value(jsondec* d, const upb_FieldDef* f);
static void jsondec_wellknownvalue(jsondec* d, upb_Message* msg,
                                   const upb_MessageDef* m);
static void jsondec_object(jsondec* d, upb_Message* msg,
                           const upb_MessageDef* m);

static bool jsondec_streql(upb_StringView str, const char* lit) {
  return str.size == strlen(lit) && memcmp(str.data, lit, str.size) == 0;
}

static bool jsondec_isnullvalue(const upb_FieldDef* f) {
  return upb_FieldDef_CType(f) == kUpb_CType_Enum &&
         strcmp(upb_EnumDef_FullName(upb_FieldDef_EnumSubDef(f)),
                "google.protobuf.NullValue") == 0;
}

static bool jsondec_isvalue(const upb_FieldDef* f) {
  return (upb_FieldDef_CType(f) == kUpb_CType_Message &&
          upb_MessageDef_WellKnownType(upb_FieldDef_MessageSubDef(f)) ==
              kUpb_WellKnown_Value) ||
         jsondec_isnullvalue(f);
}

static void jsondec_seterrmsg(jsondec* d, const char* msg) {
  upb_Status_SetErrorFormat(d->status, "Error parsing JSON @%d:%d: %s", d->line,
                            (int)(d->ptr - d->line_begin), msg);
}

UPB_NORETURN static void jsondec_err(jsondec* d, const char* msg) {
  jsondec_seterrmsg(d, msg);
  UPB_LONGJMP(d->err, 1);
}

UPB_PRINTF(2, 3)
UPB_NORETURN static void jsondec_errf(jsondec* d, const char* fmt, ...) {
  va_list argp;
  upb_Status_SetErrorFormat(d->status, "Error parsing JSON @%d:%d: ", d->line,
                            (int)(d->ptr - d->line_begin));
  va_start(argp, fmt);
  upb_Status_VAppendErrorFormat(d->status, fmt, argp);
  va_end(argp);
  UPB_LONGJMP(d->err, 1);
}

// Advances d->ptr until the next non-whitespace character or to the end of
// the buffer.
static void jsondec_consumews(jsondec* d) {
  while (d->ptr != d->end) {
    switch (*d->ptr) {
      case '\n':
        d->line++;
        d->line_begin = d->ptr;
        /* Fallthrough. */
      case '\r':
      case '\t':
      case ' ':
        d->ptr++;
        break;
      default:
        return;
    }
  }
}

// Advances d->ptr until the next non-whitespace character. Postcondition that
// d->ptr is pointing at a valid non-whitespace character (will err if end of
// buffer is reached).
static void jsondec_skipws(jsondec* d) {
  jsondec_consumews(d);
  if (d->ptr == d->end) {
    jsondec_err(d, "Unexpected EOF");
  }
}

static bool jsondec_tryparsech(jsondec* d, char ch) {
  if (d->ptr == d->end || *d->ptr != ch) return false;
  d->ptr++;
  return true;
}

static void jsondec_parselit(jsondec* d, const char* lit) {
  size_t avail = d->end - d->ptr;
  size_t len = strlen(lit);
  if (avail < len || memcmp(d->ptr, lit, len) != 0) {
    jsondec_errf(d, "Expected: '%s'", lit);
  }
  d->ptr += len;
}

static void jsondec_wsch(jsondec* d, char ch) {
  jsondec_skipws(d);
  if (!jsondec_tryparsech(d, ch)) {
    jsondec_errf(d, "Expected: '%c'", ch);
  }
}

static void jsondec_true(jsondec* d) { jsondec_parselit(d, "true"); }
static void jsondec_false(jsondec* d) { jsondec_parselit(d, "false"); }
static void jsondec_null(jsondec* d) { jsondec_parselit(d, "null"); }

static void jsondec_entrysep(jsondec* d) {
  jsondec_skipws(d);
  jsondec_parselit(d, ":");
}

static int jsondec_rawpeek(jsondec* d) {
  if (d->ptr == d->end) {
    jsondec_err(d, "Unexpected EOF");
  }

  switch (*d->ptr) {
    case '{':
      return JD_OBJECT;
    case '[':
      return JD_ARRAY;
    case '"':
      return JD_STRING;
    case '-':
    case '0':
    case '1':
    case '2':
    case '3':
    case '4':
    case '5':
    case '6':
    case '7':
    case '8':
    case '9':
      return JD_NUMBER;
    case 't':
      return JD_TRUE;
    case 'f':
      return JD_FALSE;
    case 'n':
      return JD_NULL;
    default:
      jsondec_errf(d, "Unexpected character: '%c'", *d->ptr);
  }
}

/* JSON object/array **********************************************************/

/* These are used like so:
 *
 * jsondec_objstart(d);
 * while (jsondec_objnext(d)) {
 *   ...
 * }
 * jsondec_objend(d) */

static int jsondec_peek(jsondec* d) {
  jsondec_skipws(d);
  return jsondec_rawpeek(d);
}

static void jsondec_push(jsondec* d) {
  if (--d->depth < 0) {
    jsondec_err(d, "Recursion limit exceeded");
  }
  d->is_first = true;
}

static bool jsondec_seqnext(jsondec* d, char end_ch) {
  bool is_first = d->is_first;
  d->is_first = false;
  jsondec_skipws(d);
  if (*d->ptr == end_ch) return false;
  if (!is_first) jsondec_parselit(d, ",");
  return true;
}

static void jsondec_arrstart(jsondec* d) {
  jsondec_push(d);
  jsondec_wsch(d, '[');
}

static void jsondec_arrend(jsondec* d) {
  d->depth++;
  jsondec_wsch(d, ']');
}

static bool jsondec_arrnext(jsondec* d) { return jsondec_seqnext(d, ']'); }

static void jsondec_objstart(jsondec* d) {
  jsondec_push(d);
  jsondec_wsch(d, '{');
}

static void jsondec_objend(jsondec* d) {
  d->depth++;
  jsondec_wsch(d, '}');
}

static bool jsondec_objnext(jsondec* d) {
  if (!jsondec_seqnext(d, '}')) return false;
  if (jsondec_peek(d) != JD_STRING) {
    jsondec_err(d, "Object must start with string");
  }
  return true;
}

/* JSON number ****************************************************************/

static bool jsondec_tryskipdigits(jsondec* d) {
  const char* start = d->ptr;

  while (d->ptr < d->end) {
    if (*d->ptr < '0' || *d->ptr > '9') {
      break;
    }
    d->ptr++;
  }

  return d->ptr != start;
}

static void jsondec_skipdigits(jsondec* d) {
  if (!jsondec_tryskipdigits(d)) {
    jsondec_err(d, "Expected one or more digits");
  }
}

static double jsondec_number(jsondec* d) {
  const char* start = d->ptr;

  UPB_ASSERT(jsondec_rawpeek(d) == JD_NUMBER);

  /* Skip over the syntax of a number, as specified by JSON. */
  if (*d->ptr == '-') d->ptr++;

  if (jsondec_tryparsech(d, '0')) {
    if (jsondec_tryskipdigits(d)) {
      jsondec_err(d, "number cannot have leading zero");
    }
  } else {
    jsondec_skipdigits(d);
  }

  if (d->ptr == d->end) goto parse;
  if (jsondec_tryparsech(d, '.')) {
    jsondec_skipdigits(d);
  }
  if (d->ptr == d->end) goto parse;

  if (*d->ptr == 'e' || *d->ptr == 'E') {
    d->ptr++;
    if (d->ptr == d->end) {
      jsondec_err(d, "Unexpected EOF in number");
    }
    if (*d->ptr == '+' || *d->ptr == '-') {
      d->ptr++;
    }
    jsondec_skipdigits(d);
  }

parse:
  /* Having verified the syntax of a JSON number, use strtod() to parse
   * (strtod() accepts a superset of JSON syntax). */
  errno = 0;
  {
    // Copy the number into a null-terminated scratch buffer since strtod
    // expects a null-terminated string.
    char nullz[64];
    ptrdiff_t len = d->ptr - start;
    if (len > (ptrdiff_t)(sizeof(nullz) - 1)) {
      jsondec_err(d, "excessively long number");
    }
    memcpy(nullz, start, len);
    nullz[len] = '\0';

    char* end;
    double val = strtod(nullz, &end);
    UPB_ASSERT(end - nullz == len);

    /* Currently the min/max-val conformance tests fail if we check this.  Does
     * this mean the conformance tests are wrong or strtod() is wrong, or
     * something else?  Investigate further. */
    /*
    if (errno == ERANGE) {
      jsondec_err(d, "Number out of range");
    }
    */

    if (val > DBL_MAX || val < -DBL_MAX) {
      jsondec_err(d, "Number out of range");
    }

    return val;
  }
}

/* JSON string ****************************************************************/

static char jsondec_escape(jsondec* d) {
  switch (*d->ptr++) {
    case '"':
      return '\"';
    case '\\':
      return '\\';
    case '/':
      return '/';
    case 'b':
      return '\b';
    case 'f':
      return '\f';
    case 'n':
      return '\n';
    case 'r':
      return '\r';
    case 't':
      return '\t';
    default:
      jsondec_err(d, "Invalid escape char");
  }
}

static uint32_t jsondec_codepoint(jsondec* d) {
  uint32_t cp = 0;
  const char* end;

  if (d->end - d->ptr < 4) {
    jsondec_err(d, "EOF inside string");
  }

  end = d->ptr + 4;
  while (d->ptr < end) {
    char ch = *d->ptr++;
    if (ch >= '0' && ch <= '9') {
      ch -= '0';
    } else if (ch >= 'a' && ch <= 'f') {
      ch = ch - 'a' + 10;
    } else if (ch >= 'A' && ch <= 'F') {
      ch = ch - 'A' + 10;
    } else {
      jsondec_err(d, "Invalid hex digit");
    }
    cp = (cp << 4) | ch;
  }

  return cp;
}

/* Parses a \uXXXX unicode escape (possibly a surrogate pair). */
static size_t jsondec_unicode(jsondec* d, char* out) {
  uint32_t cp = jsondec_codepoint(d);
  if (upb_Unicode_IsHigh(cp)) {
    /* Surrogate pair: two 16-bit codepoints become a 32-bit codepoint. */
    jsondec_parselit(d, "\\u");
    uint32_t low = jsondec_codepoint(d);
    if (!upb_Unicode_IsLow(low)) jsondec_err(d, "Invalid low surrogate");
    cp = upb_Unicode_FromPair(cp, low);
  } else if (upb_Unicode_IsLow(cp)) {
    jsondec_err(d, "Unpaired low surrogate");
  }

  /* Write to UTF-8 */
  int bytes = upb_Unicode_ToUTF8(cp, out);
  if (bytes == 0) jsondec_err(d, "Invalid codepoint");
  return bytes;
}

static void jsondec_resize(jsondec* d, char** buf, char** end, char** buf_end) {
  size_t oldsize = *buf_end - *buf;
  size_t len = *end - *buf;
  size_t size = UPB_MAX(8, 2 * oldsize);

  *buf = upb_Arena_Realloc(d->arena, *buf, len, size);
  if (!*buf) jsondec_err(d, "Out of memory");

  *end = *buf + len;
  *buf_end = *buf + size;
}

static upb_StringView jsondec_string(jsondec* d) {
  char* buf = NULL;
  char* end = NULL;
  char* buf_end = NULL;

  jsondec_skipws(d);

  if (*d->ptr++ != '"') {
    jsondec_err(d, "Expected string");
  }

  while (d->ptr < d->end) {
    char ch = *d->ptr++;

    if (end == buf_end) {
      jsondec_resize(d, &buf, &end, &buf_end);
    }

    switch (ch) {
      case '"': {
        upb_StringView ret;
        ret.data = buf;
        ret.size = end - buf;
        *end = '\0'; /* Needed for possible strtod(). */
        return ret;
      }
      case '\\':
        if (d->ptr == d->end) goto eof;
        if (*d->ptr == 'u') {
          d->ptr++;
          if (buf_end - end < 4) {
            /* Allow space for maximum-sized codepoint (4 bytes). */
            jsondec_resize(d, &buf, &end, &buf_end);
          }
          end += jsondec_unicode(d, end);
        } else {
          *end++ = jsondec_escape(d);
        }
        break;
      default:
        if ((unsigned char)ch < 0x20) {
          jsondec_err(d, "Invalid char in JSON string");
        }
        *end++ = ch;
        break;
    }
  }

eof:
  jsondec_err(d, "EOF inside string");
}

static void jsondec_skipval(jsondec* d) {
  switch (jsondec_peek(d)) {
    case JD_OBJECT:
      jsondec_objstart(d);
      while (jsondec_objnext(d)) {
        jsondec_string(d);
        jsondec_entrysep(d);
        jsondec_skipval(d);
      }
      jsondec_objend(d);
      break;
    case JD_ARRAY:
      jsondec_arrstart(d);
      while (jsondec_arrnext(d)) {
        jsondec_skipval(d);
      }
      jsondec_arrend(d);
      break;
    case JD_TRUE:
      jsondec_true(d);
      break;
    case JD_FALSE:
      jsondec_false(d);
      break;
    case JD_NULL:
      jsondec_null(d);
      break;
    case JD_STRING:
      jsondec_string(d);
      break;
    case JD_NUMBER:
      jsondec_number(d);
      break;
  }
}

/* Base64 decoding for bytes fields. ******************************************/

static unsigned int jsondec_base64_tablelookup(const char ch) {
  /* Table includes the normal base64 chars plus the URL-safe variant. */
  const signed char table[256] = {
      -1,       -1,       -1,       -1,       -1,       -1,        -1,
      -1,       -1,       -1,       -1,       -1,       -1,        -1,
      -1,       -1,       -1,       -1,       -1,       -1,        -1,
      -1,       -1,       -1,       -1,       -1,       -1,        -1,
      -1,       -1,       -1,       -1,       -1,       -1,        -1,
      -1,       -1,       -1,       -1,       -1,       -1,        -1,
      -1,       62 /*+*/, -1,       62 /*-*/, -1,       63 /*/ */, 52 /*0*/,
      53 /*1*/, 54 /*2*/, 55 /*3*/, 56 /*4*/, 57 /*5*/, 58 /*6*/,  59 /*7*/,
      60 /*8*/, 61 /*9*/, -1,       -1,       -1,       -1,        -1,
      -1,       -1,       0 /*A*/,  1 /*B*/,  2 /*C*/,  3 /*D*/,   4 /*E*/,
      5 /*F*/,  6 /*G*/,  07 /*H*/, 8 /*I*/,  9 /*J*/,  10 /*K*/,  11 /*L*/,
      12 /*M*/, 13 /*N*/, 14 /*O*/, 15 /*P*/, 16 /*Q*/, 17 /*R*/,  18 /*S*/,
      19 /*T*/, 20 /*U*/, 21 /*V*/, 22 /*W*/, 23 /*X*/, 24 /*Y*/,  25 /*Z*/,
      -1,       -1,       -1,       -1,       63 /*_*/, -1,        26 /*a*/,
      27 /*b*/, 28 /*c*/, 29 /*d*/, 30 /*e*/, 31 /*f*/, 32 /*g*/,  33 /*h*/,
      34 /*i*/, 35 /*j*/, 36 /*k*/, 37 /*l*/, 38 /*m*/, 39 /*n*/,  40 /*o*/,
      41 /*p*/, 42 /*q*/, 43 /*r*/, 44 /*s*/, 45 /*t*/, 46 /*u*/,  47 /*v*/,
      48 /*w*/, 49 /*x*/, 50 /*y*/, 51 /*z*/, -1,       -1,        -1,
      -1,       -1,       -1,       -1,       -1,       -1,        -1,
      -1,       -1,       -1,       -1,       -1,       -1,        -1,
      -1,       -1,       -1,       -1,       -1,       -1,        -1,
      -1,       -1,       -1,       -1,       -1,       -1,        -1,
      -1,       -1,       -1,       -1,       -1,       -1,        -1,
      -1,       -1,       -1,       -1,       -1,       -1,        -1,
      -1,       -1,       -1,       -1,       -1,       -1,        -1,
      -1,       -1,       -1,       -1,       -1,       -1,        -1,
      -1,       -1,       -1,       -1,       -1,       -1,        -1,
      -1,       -1,       -1,       -1,       -1,       -1,        -1,
      -1,       -1,       -1,       -1,       -1,       -1,        -1,
      -1,       -1,       -1,       -1,       -1,       -1,        -1,
      -1,       -1,       -1,       -1,       -1,       -1,        -1,
      -1,       -1,       -1,       -1,       -1,       -1,        -1,
      -1,       -1,       -1,       -1,       -1,       -1,        -1,
      -1,       -1,       -1,       -1,       -1,       -1,        -1,
      -1,       -1,       -1,       -1,       -1,       -1,        -1,
      -1,       -1,       -1,       -1,       -1,       -1,        -1,
      -1,       -1,       -1,       -1};

  /* Sign-extend return value so high bit will be set on any unexpected char. */
  return table[(unsigned)ch];
}

static char* jsondec_partialbase64(jsondec* d, const char* ptr, const char* end,
                                   char* out) {
  int32_t val = -1;

  switch (end - ptr) {
    case 2:
      val = jsondec_base64_tablelookup(ptr[0]) << 18 |
            jsondec_base64_tablelookup(ptr[1]) << 12;
      out[0] = val >> 16;
      out += 1;
      break;
    case 3:
      val = jsondec_base64_tablelookup(ptr[0]) << 18 |
            jsondec_base64_tablelookup(ptr[1]) << 12 |
            jsondec_base64_tablelookup(ptr[2]) << 6;
      out[0] = val >> 16;
      out[1] = (val >> 8) & 0xff;
      out += 2;
      break;
  }

  if (val < 0) {
    jsondec_err(d, "Corrupt base64");
  }

  return out;
}

static size_t jsondec_base64(jsondec* d, upb_StringView str) {
  /* We decode in place. This is safe because this is a new buffer (not
   * aliasing the input) and because base64 decoding shrinks 4 bytes into 3. */
  char* out = (char*)str.data;
  const char* ptr = str.data;
  const char* end = ptr + str.size;
  const char* end4 = ptr + (str.size & -4); /* Round down to multiple of 4. */

  for (; ptr < end4; ptr += 4, out += 3) {
    int val = jsondec_base64_tablelookup(ptr[0]) << 18 |
              jsondec_base64_tablelookup(ptr[1]) << 12 |
              jsondec_base64_tablelookup(ptr[2]) << 6 |
              jsondec_base64_tablelookup(ptr[3]) << 0;

    if (val < 0) {
      /* Junk chars or padding. Remove trailing padding, if any. */
      if (end - ptr == 4 && ptr[3] == '=') {
        if (ptr[2] == '=') {
          end -= 2;
        } else {
          end -= 1;
        }
      }
      break;
    }

    out[0] = val >> 16;
    out[1] = (val >> 8) & 0xff;
    out[2] = val & 0xff;
  }

  if (ptr < end) {
    /* Process remaining chars. We do not require padding. */
    out = jsondec_partialbase64(d, ptr, end, out);
  }

  return out - str.data;
}

/* Low-level integer parsing **************************************************/

static const char* jsondec_buftouint64(jsondec* d, const char* ptr,
                                       const char* end, uint64_t* val) {
  const char* out = upb_BufToUint64(ptr, end, val);
  if (!out) jsondec_err(d, "Integer overflow");
  return out;
}

static const char* jsondec_buftoint64(jsondec* d, const char* ptr,
                                      const char* end, int64_t* val,
                                      bool* is_neg) {
  const char* out = upb_BufToInt64(ptr, end, val, is_neg);
  if (!out) jsondec_err(d, "Integer overflow");
  return out;
}

static uint64_t jsondec_strtouint64(jsondec* d, upb_StringView str) {
  const char* end = str.data + str.size;
  uint64_t ret;
  if (jsondec_buftouint64(d, str.data, end, &ret) != end) {
    jsondec_err(d, "Non-number characters in quoted integer");
  }
  return ret;
}

static int64_t jsondec_strtoint64(jsondec* d, upb_StringView str) {
  const char* end = str.data + str.size;
  int64_t ret;
  if (jsondec_buftoint64(d, str.data, end, &ret, NULL) != end) {
    jsondec_err(d, "Non-number characters in quoted integer");
  }
  return ret;
}

static void jsondec_checkempty(jsondec* d, upb_StringView str,
                               const upb_FieldDef* f) {
  if (str.size != 0) return;
  d->result = kUpb_JsonDecodeResult_Error;
  upb_Status_SetErrorFormat(d->status,
                            "Empty string is not a valid number (field: %s). "
                            "This will be an error in a future version.",
                            upb_FieldDef_FullName(f));
}

/* Primitive value types ******************************************************/

/* Parse INT32 or INT64 value. */
static upb_MessageValue jsondec_int(jsondec* d, const upb_FieldDef* f) {
  upb_MessageValue val;

  switch (jsondec_peek(d)) {
    case JD_NUMBER: {
      double dbl = jsondec_number(d);
      if (dbl > 9223372036854774784.0 || dbl < -9223372036854775808.0) {
        jsondec_err(d, "JSON number is out of range.");
      }
      val.int64_val = dbl; /* must be guarded, overflow here is UB */
      if (val.int64_val != dbl) {
        jsondec_errf(d, "JSON number was not integral (%f != %" PRId64 ")", dbl,
                     val.int64_val);
      }
      break;
    }
    case JD_STRING: {
      upb_StringView str = jsondec_string(d);
      jsondec_checkempty(d, str, f);
      val.int64_val = jsondec_strtoint64(d, str);
      break;
    }
    default:
      jsondec_err(d, "Expected number or string");
  }

  if (upb_FieldDef_CType(f) == kUpb_CType_Int32 ||
      upb_FieldDef_CType(f) == kUpb_CType_Enum) {
    if (val.int64_val > INT32_MAX || val.int64_val < INT32_MIN) {
      jsondec_err(d, "Integer out of range.");
    }
    val.int32_val = (int32_t)val.int64_val;
  }

  return val;
}

/* Parse UINT32 or UINT64 value. */
static upb_MessageValue jsondec_uint(jsondec* d, const upb_FieldDef* f) {
  upb_MessageValue val;

  switch (jsondec_peek(d)) {
    case JD_NUMBER: {
      double dbl = jsondec_number(d);
      if (dbl > 18446744073709549568.0 || dbl < 0) {
        jsondec_err(d, "JSON number is out of range.");
      }
      val.uint64_val = dbl; /* must be guarded, overflow here is UB */
      if (val.uint64_val != dbl) {
        jsondec_errf(d, "JSON number was not integral (%f != %" PRIu64 ")", dbl,
                     val.uint64_val);
      }
      break;
    }
    case JD_STRING: {
      upb_StringView str = jsondec_string(d);
      jsondec_checkempty(d, str, f);
      val.uint64_val = jsondec_strtouint64(d, str);
      break;
    }
    default:
      jsondec_err(d, "Expected number or string");
  }

  if (upb_FieldDef_CType(f) == kUpb_CType_UInt32) {
    if (val.uint64_val > UINT32_MAX) {
      jsondec_err(d, "Integer out of range.");
    }
    val.uint32_val = (uint32_t)val.uint64_val;
  }

  return val;
}

/* Parse DOUBLE or FLOAT value. */
static upb_MessageValue jsondec_double(jsondec* d, const upb_FieldDef* f) {
  upb_StringView str;
  upb_MessageValue val;

  switch (jsondec_peek(d)) {
    case JD_NUMBER:
      val.double_val = jsondec_number(d);
      break;
    case JD_STRING:
      str = jsondec_string(d);
      if (str.size == 0) {
        jsondec_checkempty(d, str, f);
        val.double_val = 0.0;
      } else if (jsondec_streql(str, "NaN")) {
        val.double_val = NAN;
      } else if (jsondec_streql(str, "Infinity")) {
        val.double_val = INFINITY;
      } else if (jsondec_streql(str, "-Infinity")) {
        val.double_val = -INFINITY;
      } else {
        char* end;
        val.double_val = strtod(str.data, &end);
        if (end != str.data + str.size) {
          d->result = kUpb_JsonDecodeResult_Error;
          upb_Status_SetErrorFormat(
              d->status,
              "Non-number characters in quoted number (field: %s). "
              "This will be an error in a future version.",
              upb_FieldDef_FullName(f));
        }
      }
      break;
    default:
      jsondec_err(d, "Expected number or string");
  }

  if (upb_FieldDef_CType(f) == kUpb_CType_Float) {
    float f = val.double_val;
    if (val.double_val != INFINITY && val.double_val != -INFINITY) {
      if (f == INFINITY || f == -INFINITY) jsondec_err(d, "Float out of range");
    }
    val.float_val = f;
  }

  return val;
}

/* Parse STRING or BYTES value. */
static upb_MessageValue jsondec_strfield(jsondec* d, const upb_FieldDef* f) {
  upb_MessageValue val;
  val.str_val = jsondec_string(d);
  if (upb_FieldDef_CType(f) == kUpb_CType_Bytes) {
    val.str_val.size = jsondec_base64(d, val.str_val);
  }
  return val;
}

static upb_JsonMessageValue jsondec_enum(jsondec* d, const upb_FieldDef* f) {
  switch (jsondec_peek(d)) {
    case JD_STRING: {
      upb_StringView str = jsondec_string(d);
      const upb_EnumDef* e = upb_FieldDef_EnumSubDef(f);
      const upb_EnumValueDef* ev =
          upb_EnumDef_FindValueByNameWithSize(e, str.data, str.size);
      upb_JsonMessageValue val = {.ignore = false};
      if (ev) {
        val.value.int32_val = upb_EnumValueDef_Number(ev);
      } else {
        if (d->options & upb_JsonDecode_IgnoreUnknown) {
          val.ignore = true;
        } else {
          jsondec_errf(d, "Unknown enumerator: '" UPB_STRINGVIEW_FORMAT "'",
                       UPB_STRINGVIEW_ARGS(str));
        }
      }
      return val;
    }
    case JD_NULL: {
      if (jsondec_isnullvalue(f)) {
        upb_JsonMessageValue val = {.ignore = false};
        jsondec_null(d);
        val.value.int32_val = 0;
        return val;
      }
    }
      /* Fallthrough. */
    default:
      return (upb_JsonMessageValue){.value = jsondec_int(d, f),
                                    .ignore = false};
  }
}

static upb_MessageValue jsondec_bool(jsondec* d, const upb_FieldDef* f) {
  bool is_map_key = upb_FieldDef_Number(f) == 1 &&
                    upb_MessageDef_IsMapEntry(upb_FieldDef_ContainingType(f));
  upb_MessageValue val;

  if (is_map_key) {
    upb_StringView str = jsondec_string(d);
    if (jsondec_streql(str, "true")) {
      val.bool_val = true;
    } else if (jsondec_streql(str, "false")) {
      val.bool_val = false;
    } else {
      jsondec_err(d, "Invalid boolean map key");
    }
  } else {
    switch (jsondec_peek(d)) {
      case JD_TRUE:
        val.bool_val = true;
        jsondec_true(d);
        break;
      case JD_FALSE:
        val.bool_val = false;
        jsondec_false(d);
        break;
      default:
        jsondec_err(d, "Expected true or false");
    }
  }

  return val;
}

/* Composite types (array/message/map) ****************************************/

static void jsondec_array(jsondec* d, upb_Message* msg, const upb_FieldDef* f) {
  UPB_ASSERT(!upb_Message_IsFrozen(msg));
  upb_Array* arr = upb_Message_Mutable(msg, f, d->arena).array;

  jsondec_arrstart(d);
  while (jsondec_arrnext(d)) {
    upb_JsonMessageValue elem = jsondec_value(d, f);
    if (!elem.ignore) {
      upb_Array_Append(arr, elem.value, d->arena);
    }
  }
  jsondec_arrend(d);
}

static void jsondec_map(jsondec* d, upb_Message* msg, const upb_FieldDef* f) {
  UPB_ASSERT(!upb_Message_IsFrozen(msg));
  upb_Map* map = upb_Message_Mutable(msg, f, d->arena).map;
  const upb_MessageDef* entry = upb_FieldDef_MessageSubDef(f);
  const upb_FieldDef* key_f = upb_MessageDef_FindFieldByNumber(entry, 1);
  const upb_FieldDef* val_f = upb_MessageDef_FindFieldByNumber(entry, 2);

  jsondec_objstart(d);
  while (jsondec_objnext(d)) {
    upb_JsonMessageValue key, val;
    key = jsondec_value(d, key_f);
    UPB_ASSUME(!key.ignore);  // Map key cannot be enum.
    jsondec_entrysep(d);
    val = jsondec_value(d, val_f);
    if (!val.ignore) {
      upb_Map_Set(map, key.value, val.value, d->arena);
    }
  }
  jsondec_objend(d);
}

static void jsondec_tomsg(jsondec* d, upb_Message* msg,
                          const upb_MessageDef* m) {
  UPB_ASSERT(!upb_Message_IsFrozen(msg));
  if (upb_MessageDef_WellKnownType(m) == kUpb_WellKnown_Unspecified) {
    jsondec_object(d, msg, m);
  } else {
    jsondec_wellknown(d, msg, m);
  }
}

static upb_MessageValue jsondec_msg(jsondec* d, const upb_FieldDef* f) {
  const upb_MessageDef* m = upb_FieldDef_MessageSubDef(f);
  const upb_MiniTable* layout = upb_MessageDef_MiniTable(m);
  upb_Message* msg = upb_Message_New(layout, d->arena);
  upb_MessageValue val;

  jsondec_tomsg(d, msg, m);
  val.msg_val = msg;
  return val;
}

static void jsondec_field(jsondec* d, upb_Message* msg,
                          const upb_MessageDef* m) {
  UPB_ASSERT(!upb_Message_IsFrozen(msg));
  upb_StringView name;
  const upb_FieldDef* f;
  const upb_FieldDef* preserved;

  name = jsondec_string(d);
  jsondec_entrysep(d);

  if (name.size >= 2 && name.data[0] == '[' &&
      name.data[name.size - 1] == ']') {
    f = upb_DefPool_FindExtensionByNameWithSize(d->symtab, name.data + 1,
                                                name.size - 2);
    if (f && upb_FieldDef_ContainingType(f) != m) {
      jsondec_errf(
          d, "Extension %s extends message %s, but was seen in message %s",
          upb_FieldDef_FullName(f),
          upb_MessageDef_FullName(upb_FieldDef_ContainingType(f)),
          upb_MessageDef_FullName(m));
    }
  } else {
    f = upb_MessageDef_FindByJsonNameWithSize(m, name.data, name.size);
  }

  if (!f) {
    if ((d->options & upb_JsonDecode_IgnoreUnknown) == 0) {
      jsondec_errf(d, "No such field: " UPB_STRINGVIEW_FORMAT,
                   UPB_STRINGVIEW_ARGS(name));
    }
    jsondec_skipval(d);
    return;
  }

  if (jsondec_peek(d) == JD_NULL && !jsondec_isvalue(f)) {
    /* JSON "null" indicates a default value, so no need to set anything. */
    jsondec_null(d);
    return;
  }

  if (upb_FieldDef_RealContainingOneof(f) &&
      upb_Message_WhichOneofByDef(msg, upb_FieldDef_ContainingOneof(f))) {
    jsondec_err(d, "More than one field for this oneof.");
  }

  preserved = d->debug_field;
  d->debug_field = f;

  if (upb_FieldDef_IsMap(f)) {
    jsondec_map(d, msg, f);
  } else if (upb_FieldDef_IsRepeated(f)) {
    jsondec_array(d, msg, f);
  } else if (upb_FieldDef_IsSubMessage(f)) {
    upb_Message* submsg = upb_Message_Mutable(msg, f, d->arena).msg;
    const upb_MessageDef* subm = upb_FieldDef_MessageSubDef(f);
    jsondec_tomsg(d, submsg, subm);
  } else {
    upb_JsonMessageValue val = jsondec_value(d, f);
    if (!val.ignore) {
      upb_Message_SetFieldByDef(msg, f, val.value, d->arena);
    }
  }

  d->debug_field = preserved;
}

static void jsondec_object(jsondec* d, upb_Message* msg,
                           const upb_MessageDef* m) {
  UPB_ASSERT(!upb_Message_IsFrozen(msg));
  jsondec_objstart(d);
  while (jsondec_objnext(d)) {
    jsondec_field(d, msg, m);
  }
  jsondec_objend(d);
}

static upb_MessageValue jsondec_nonenum(jsondec* d, const upb_FieldDef* f) {
  switch (upb_FieldDef_CType(f)) {
    case kUpb_CType_Bool:
      return jsondec_bool(d, f);
    case kUpb_CType_Float:
    case kUpb_CType_Double:
      return jsondec_double(d, f);
    case kUpb_CType_UInt32:
    case kUpb_CType_UInt64:
      return jsondec_uint(d, f);
    case kUpb_CType_Int32:
    case kUpb_CType_Int64:
      return jsondec_int(d, f);
    case kUpb_CType_String:
    case kUpb_CType_Bytes:
      return jsondec_strfield(d, f);
    case kUpb_CType_Message:
      return jsondec_msg(d, f);
    case kUpb_CType_Enum:
    default:
      UPB_UNREACHABLE();
  }
}

static upb_JsonMessageValue jsondec_value(jsondec* d, const upb_FieldDef* f) {
  if (upb_FieldDef_CType(f) == kUpb_CType_Enum) {
    return jsondec_enum(d, f);
  } else {
    return (upb_JsonMessageValue){.value = jsondec_nonenum(d, f),
                                  .ignore = false};
  }
}

/* Well-known types ***********************************************************/

static int jsondec_tsdigits(jsondec* d, const char** ptr, size_t digits,
                            const char* after) {
  uint64_t val;
  const char* p = *ptr;
  const char* end = p + digits;
  size_t after_len = after ? strlen(after) : 0;

  UPB_ASSERT(digits <= 9); /* int can't overflow. */

  if (jsondec_buftouint64(d, p, end, &val) != end ||
      (after_len && memcmp(end, after, after_len) != 0)) {
    jsondec_err(d, "Malformed timestamp");
  }

  UPB_ASSERT(val < INT_MAX);

  *ptr = end + after_len;
  return (int)val;
}

static int jsondec_nanos(jsondec* d, const char** ptr, const char* end) {
  uint64_t nanos = 0;
  const char* p = *ptr;

  if (p != end && *p == '.') {
    const char* nano_end = jsondec_buftouint64(d, p + 1, end, &nanos);
    int digits = (int)(nano_end - p - 1);
    int exp_lg10 = 9 - digits;
    if (digits > 9) {
      jsondec_err(d, "Too many digits for partial seconds");
    }
    while (exp_lg10--) nanos *= 10;
    *ptr = nano_end;
  }

  UPB_ASSERT(nanos < INT_MAX);

  return (int)nanos;
}

/* jsondec_epochdays(1970, 1, 1) == 1970-01-01 == 0. */
int jsondec_epochdays(int y, int m, int d) {
  const uint32_t year_base = 4800; /* Before min year, multiple of 400. */
  const uint32_t m_adj = m - 3;    /* March-based month. */
  const uint32_t carry = m_adj > (uint32_t)m ? 1 : 0;
  const uint32_t adjust = carry ? 12 : 0;
  const uint32_t y_adj = y + year_base - carry;
  const uint32_t month_days = ((m_adj + adjust) * 62719 + 769) / 2048;
  const uint32_t leap_days = y_adj / 4 - y_adj / 100 + y_adj / 400;
  return y_adj * 365 + leap_days + month_days + (d - 1) - 2472632;
}

static int64_t jsondec_unixtime(int y, int m, int d, int h, int min, int s) {
  return (int64_t)jsondec_epochdays(y, m, d) * 86400 + h * 3600 + min * 60 + s;
}

static void jsondec_timestamp(jsondec* d, upb_Message* msg,
                              const upb_MessageDef* m) {
  UPB_ASSERT(!upb_Message_IsFrozen(msg));
  upb_MessageValue seconds;
  upb_MessageValue nanos;
  upb_StringView str = jsondec_string(d);
  const char* ptr = str.data;
  const char* end = ptr + str.size;

  if (str.size < 20) goto malformed;

  {
    /* 1972-01-01T01:00:00 */
    int year = jsondec_tsdigits(d, &ptr, 4, "-");
    int mon = jsondec_tsdigits(d, &ptr, 2, "-");
    int day = jsondec_tsdigits(d, &ptr, 2, "T");
    int hour = jsondec_tsdigits(d, &ptr, 2, ":");
    int min = jsondec_tsdigits(d, &ptr, 2, ":");
    int sec = jsondec_tsdigits(d, &ptr, 2, NULL);

    seconds.int64_val = jsondec_unixtime(year, mon, day, hour, min, sec);
  }

  nanos.int32_val = jsondec_nanos(d, &ptr, end);

  {
    /* [+-]08:00 or Z */
    int ofs_hour = 0;
    int ofs_min = 0;
    bool neg = false;

    if (ptr == end) goto malformed;

    switch (*ptr++) {
      case '-':
        neg = true;
        /* fallthrough */
      case '+':
        if ((end - ptr) != 5) goto malformed;
        ofs_hour = jsondec_tsdigits(d, &ptr, 2, ":");
        ofs_min = jsondec_tsdigits(d, &ptr, 2, NULL);
        ofs_min = ((ofs_hour * 60) + ofs_min) * 60;
        seconds.int64_val += (neg ? ofs_min : -ofs_min);
        break;
      case 'Z':
        if (ptr != end) goto malformed;
        break;
      default:
        goto malformed;
    }
  }

  if (seconds.int64_val < -62135596800) {
    jsondec_err(d, "Timestamp out of range");
  }

  upb_Message_SetFieldByDef(msg, upb_MessageDef_FindFieldByNumber(m, 1),
                            seconds, d->arena);
  upb_Message_SetFieldByDef(msg, upb_MessageDef_FindFieldByNumber(m, 2), nanos,
                            d->arena);
  return;

malformed:
  jsondec_err(d, "Malformed timestamp");
}

static void jsondec_duration(jsondec* d, upb_Message* msg,
                             const upb_MessageDef* m) {
  UPB_ASSERT(!upb_Message_IsFrozen(msg));
  upb_MessageValue seconds;
  upb_MessageValue nanos;
  upb_StringView str = jsondec_string(d);
  const char* ptr = str.data;
  const char* end = ptr + str.size;
  const int64_t max = (uint64_t)3652500 * 86400;
  bool neg = false;

  /* "3.000000001s", "3s", etc. */
  ptr = jsondec_buftoint64(d, ptr, end, &seconds.int64_val, &neg);
  nanos.int32_val = jsondec_nanos(d, &ptr, end);

  if (end - ptr != 1 || *ptr != 's') {
    jsondec_err(d, "Malformed duration");
  }

  if (seconds.int64_val < -max || seconds.int64_val > max) {
    jsondec_err(d, "Duration out of range");
  }

  if (neg) {
    nanos.int32_val = -nanos.int32_val;
  }

  upb_Message_SetFieldByDef(msg, upb_MessageDef_FindFieldByNumber(m, 1),
                            seconds, d->arena);
  upb_Message_SetFieldByDef(msg, upb_MessageDef_FindFieldByNumber(m, 2), nanos,
                            d->arena);
}

static void jsondec_listvalue(jsondec* d, upb_Message* msg,
                              const upb_MessageDef* m) {
  UPB_ASSERT(!upb_Message_IsFrozen(msg));
  const upb_FieldDef* values_f = upb_MessageDef_FindFieldByNumber(m, 1);
  const upb_MessageDef* value_m = upb_FieldDef_MessageSubDef(values_f);
  const upb_MiniTable* value_layout = upb_MessageDef_MiniTable(value_m);
  upb_Array* values = upb_Message_Mutable(msg, values_f, d->arena).array;

  jsondec_arrstart(d);
  while (jsondec_arrnext(d)) {
    upb_Message* value_msg = upb_Message_New(value_layout, d->arena);
    upb_MessageValue value;
    value.msg_val = value_msg;
    upb_Array_Append(values, value, d->arena);
    jsondec_wellknownvalue(d, value_msg, value_m);
  }
  jsondec_arrend(d);
}

static void jsondec_struct(jsondec* d, upb_Message* msg,
                           const upb_MessageDef* m) {
  UPB_ASSERT(!upb_Message_IsFrozen(msg));
  const upb_FieldDef* fields_f = upb_MessageDef_FindFieldByNumber(m, 1);
  const upb_MessageDef* entry_m = upb_FieldDef_MessageSubDef(fields_f);
  const upb_FieldDef* value_f = upb_MessageDef_FindFieldByNumber(entry_m, 2);
  const upb_MessageDef* value_m = upb_FieldDef_MessageSubDef(value_f);
  const upb_MiniTable* value_layout = upb_MessageDef_MiniTable(value_m);
  upb_Map* fields = upb_Message_Mutable(msg, fields_f, d->arena).map;

  jsondec_objstart(d);
  while (jsondec_objnext(d)) {
    upb_MessageValue key, value;
    upb_Message* value_msg = upb_Message_New(value_layout, d->arena);
    key.str_val = jsondec_string(d);
    value.msg_val = value_msg;
    upb_Map_Set(fields, key, value, d->arena);
    jsondec_entrysep(d);
    jsondec_wellknownvalue(d, value_msg, value_m);
  }
  jsondec_objend(d);
}

static void jsondec_wellknownvalue(jsondec* d, upb_Message* msg,
                                   const upb_MessageDef* m) {
  UPB_ASSERT(!upb_Message_IsFrozen(msg));
  upb_MessageValue val;
  const upb_FieldDef* f;
  upb_Message* submsg;

  switch (jsondec_peek(d)) {
    case JD_NUMBER:
      /* double number_value = 2; */
      f = upb_MessageDef_FindFieldByNumber(m, 2);
      val.double_val = jsondec_number(d);
      break;
    case JD_STRING:
      /* string string_value = 3; */
      f = upb_MessageDef_FindFieldByNumber(m, 3);
      val.str_val = jsondec_string(d);
      break;
    case JD_FALSE:
      /* bool bool_value = 4; */
      f = upb_MessageDef_FindFieldByNumber(m, 4);
      val.bool_val = false;
      jsondec_false(d);
      break;
    case JD_TRUE:
      /* bool bool_value = 4; */
      f = upb_MessageDef_FindFieldByNumber(m, 4);
      val.bool_val = true;
      jsondec_true(d);
      break;
    case JD_NULL:
      /* NullValue null_value = 1; */
      f = upb_MessageDef_FindFieldByNumber(m, 1);
      val.int32_val = 0;
      jsondec_null(d);
      break;
    /* Note: these cases return, because upb_Message_Mutable() is enough. */
    case JD_OBJECT:
      /* Struct struct_value = 5; */
      f = upb_MessageDef_FindFieldByNumber(m, 5);
      submsg = upb_Message_Mutable(msg, f, d->arena).msg;
      jsondec_struct(d, submsg, upb_FieldDef_MessageSubDef(f));
      return;
    case JD_ARRAY:
      /* ListValue list_value = 6; */
      f = upb_MessageDef_FindFieldByNumber(m, 6);
      submsg = upb_Message_Mutable(msg, f, d->arena).msg;
      jsondec_listvalue(d, submsg, upb_FieldDef_MessageSubDef(f));
      return;
    default:
      UPB_UNREACHABLE();
  }

  upb_Message_SetFieldByDef(msg, f, val, d->arena);
}

static upb_StringView jsondec_mask(jsondec* d, const char* buf,
                                   const char* end) {
  /* FieldMask fields grow due to inserted '_' characters, so we can't do the
   * transform in place. */
  const char* ptr = buf;
  upb_StringView ret;
  char* out;

  ret.size = end - ptr;
  while (ptr < end) {
    ret.size += (*ptr >= 'A' && *ptr <= 'Z');
    ptr++;
  }

  out = upb_Arena_Malloc(d->arena, ret.size);
  ptr = buf;
  ret.data = out;

  while (ptr < end) {
    char ch = *ptr++;
    if (ch >= 'A' && ch <= 'Z') {
      *out++ = '_';
      *out++ = ch + 32;
    } else if (ch == '_') {
      jsondec_err(d, "field mask may not contain '_'");
    } else {
      *out++ = ch;
    }
  }

  return ret;
}

static void jsondec_fieldmask(jsondec* d, upb_Message* msg,
                              const upb_MessageDef* m) {
  UPB_ASSERT(!upb_Message_IsFrozen(msg));
  /* repeated string paths = 1; */
  const upb_FieldDef* paths_f = upb_MessageDef_FindFieldByNumber(m, 1);
  upb_Array* arr = upb_Message_Mutable(msg, paths_f, d->arena).array;
  upb_StringView str = jsondec_string(d);
  const char* ptr = str.data;
  const char* end = ptr + str.size;
  upb_MessageValue val;

  while (ptr < end) {
    const char* elem_end = memchr(ptr, ',', end - ptr);
    if (elem_end) {
      val.str_val = jsondec_mask(d, ptr, elem_end);
      ptr = elem_end + 1;
    } else {
      val.str_val = jsondec_mask(d, ptr, end);
      ptr = end;
    }
    upb_Array_Append(arr, val, d->arena);
  }
}

static void jsondec_anyfield(jsondec* d, upb_Message* msg,
                             const upb_MessageDef* m) {
  UPB_ASSERT(!upb_Message_IsFrozen(msg));
  if (upb_MessageDef_WellKnownType(m) == kUpb_WellKnown_Unspecified) {
    /* For regular types: {"@type": "[user type]", "f1": <V1>, "f2": <V2>}
     * where f1, f2, etc. are the normal fields of this type. */
    jsondec_field(d, msg, m);
  } else {
    /* For well-known types: {"@type": "[well-known type]", "value": <X>}
     * where <X> is whatever encoding the WKT normally uses. */
    upb_StringView str = jsondec_string(d);
    jsondec_entrysep(d);
    if (!jsondec_streql(str, "value")) {
      jsondec_err(d, "Key for well-known type must be 'value'");
    }
    jsondec_wellknown(d, msg, m);
  }
}

static const upb_MessageDef* jsondec_typeurl(jsondec* d, upb_Message* msg,
                                             const upb_MessageDef* m) {
  UPB_ASSERT(!upb_Message_IsFrozen(msg));
  const upb_FieldDef* type_url_f = upb_MessageDef_FindFieldByNumber(m, 1);
  const upb_MessageDef* type_m;
  upb_StringView type_url = jsondec_string(d);
  const char* end = type_url.data + type_url.size;
  const char* ptr = end;
  upb_MessageValue val;

  val.str_val = type_url;
  upb_Message_SetFieldByDef(msg, type_url_f, val, d->arena);

  /* Find message name after the last '/' */
  while (ptr > type_url.data && *--ptr != '/') {
  }

  if (ptr == type_url.data || ptr == end) {
    jsondec_err(d, "Type url must have at least one '/' and non-empty host");
  }

  ptr++;
  type_m = upb_DefPool_FindMessageByNameWithSize(d->symtab, ptr, end - ptr);

  if (!type_m) {
    jsondec_err(d, "Type was not found");
  }

  return type_m;
}

static void jsondec_any(jsondec* d, upb_Message* msg, const upb_MessageDef* m) {
  UPB_ASSERT(!upb_Message_IsFrozen(msg));
  /* string type_url = 1;
   * bytes value = 2; */
  const upb_FieldDef* value_f = upb_MessageDef_FindFieldByNumber(m, 2);
  upb_Message* any_msg;
  const upb_MessageDef* any_m = NULL;
  const char* pre_type_data = NULL;
  const char* pre_type_end = NULL;
  upb_MessageValue encoded;

  jsondec_objstart(d);

  /* Scan looking for "@type", which is not necessarily first. */
  while (!any_m && jsondec_objnext(d)) {
    const char* start = d->ptr;
    upb_StringView name = jsondec_string(d);
    jsondec_entrysep(d);
    if (jsondec_streql(name, "@type")) {
      any_m = jsondec_typeurl(d, msg, m);
      if (pre_type_data) {
        pre_type_end = start;
        while (*pre_type_end != ',') pre_type_end--;
      }
    } else {
      if (!pre_type_data) pre_type_data = start;
      jsondec_skipval(d);
    }
  }

  if (!any_m) {
    jsondec_err(d, "Any object didn't contain a '@type' field");
  }

  const upb_MiniTable* any_layout = upb_MessageDef_MiniTable(any_m);
  any_msg = upb_Message_New(any_layout, d->arena);

  if (pre_type_data) {
    size_t len = pre_type_end - pre_type_data + 1;
    char* tmp = upb_Arena_Malloc(d->arena, len);
    const char* saved_ptr = d->ptr;
    const char* saved_end = d->end;
    memcpy(tmp, pre_type_data, len - 1);
    tmp[len - 1] = '}';
    d->ptr = tmp;
    d->end = tmp + len;
    d->is_first = true;
    while (jsondec_objnext(d)) {
      jsondec_anyfield(d, any_msg, any_m);
    }
    d->ptr = saved_ptr;
    d->end = saved_end;
  }

  while (jsondec_objnext(d)) {
    jsondec_anyfield(d, any_msg, any_m);
  }

  jsondec_objend(d);

  upb_EncodeStatus status =
      upb_Encode(any_msg, upb_MessageDef_MiniTable(any_m), 0, d->arena,
                 (char**)&encoded.str_val.data, &encoded.str_val.size);
  // TODO: We should fail gracefully here on a bad return status.
  UPB_ASSERT(status == kUpb_EncodeStatus_Ok);
  upb_Message_SetFieldByDef(msg, value_f, encoded, d->arena);
}

static void jsondec_wrapper(jsondec* d, upb_Message* msg,
                            const upb_MessageDef* m) {
  UPB_ASSERT(!upb_Message_IsFrozen(msg));
  const upb_FieldDef* value_f = upb_MessageDef_FindFieldByNumber(m, 1);
  upb_JsonMessageValue val = jsondec_value(d, value_f);
  UPB_ASSUME(val.ignore == false);  // Wrapper cannot be an enum.
  upb_Message_SetFieldByDef(msg, value_f, val.value, d->arena);
}

static void jsondec_wellknown(jsondec* d, upb_Message* msg,
                              const upb_MessageDef* m) {
  UPB_ASSERT(!upb_Message_IsFrozen(msg));
  switch (upb_MessageDef_WellKnownType(m)) {
    case kUpb_WellKnown_Any:
      jsondec_any(d, msg, m);
      break;
    case kUpb_WellKnown_FieldMask:
      jsondec_fieldmask(d, msg, m);
      break;
    case kUpb_WellKnown_Duration:
      jsondec_duration(d, msg, m);
      break;
    case kUpb_WellKnown_Timestamp:
      jsondec_timestamp(d, msg, m);
      break;
    case kUpb_WellKnown_Value:
      jsondec_wellknownvalue(d, msg, m);
      break;
    case kUpb_WellKnown_ListValue:
      jsondec_listvalue(d, msg, m);
      break;
    case kUpb_WellKnown_Struct:
      jsondec_struct(d, msg, m);
      break;
    case kUpb_WellKnown_DoubleValue:
    case kUpb_WellKnown_FloatValue:
    case kUpb_WellKnown_Int64Value:
    case kUpb_WellKnown_UInt64Value:
    case kUpb_WellKnown_Int32Value:
    case kUpb_WellKnown_UInt32Value:
    case kUpb_WellKnown_StringValue:
    case kUpb_WellKnown_BytesValue:
    case kUpb_WellKnown_BoolValue:
      jsondec_wrapper(d, msg, m);
      break;
    default:
      UPB_UNREACHABLE();
  }
}

static int upb_JsonDecoder_Decode(jsondec* const d, upb_Message* const msg,
                                  const upb_MessageDef* const m) {
  UPB_ASSERT(!upb_Message_IsFrozen(msg));
  if (UPB_SETJMP(d->err)) return kUpb_JsonDecodeResult_Error;

  jsondec_tomsg(d, msg, m);

  // Consume any trailing whitespace before checking if we read the entire
  // input.
  jsondec_consumews(d);

  if (d->ptr == d->end) {
    return d->result;
  } else {
    jsondec_seterrmsg(d, "unexpected trailing characters");
    return kUpb_JsonDecodeResult_Error;
  }
}

int upb_JsonDecodeDetectingNonconformance(const char* buf, size_t size,
                                          upb_Message* msg,
                                          const upb_MessageDef* m,
                                          const upb_DefPool* symtab,
                                          int options, upb_Arena* arena,
                                          upb_Status* status) {
  UPB_ASSERT(!upb_Message_IsFrozen(msg));
  jsondec d;

  if (size == 0) return true;

  d.ptr = buf;
  d.end = buf + size;
  d.arena = arena;
  d.symtab = symtab;
  d.status = status;
  d.options = options;
  d.depth = 64;
  d.result = kUpb_JsonDecodeResult_Ok;
  d.line = 1;
  d.line_begin = d.ptr;
  d.debug_field = NULL;
  d.is_first = false;

  return upb_JsonDecoder_Decode(&d, msg, m);
}


#include <ctype.h>
#include <float.h>
#include <inttypes.h>
#include <math.h>
#include <stdarg.h>
#include <string.h>


// Must be last.

typedef struct {
  char *buf, *ptr, *end;
  size_t overflow;
  int indent_depth;
  int options;
  const upb_DefPool* ext_pool;
  jmp_buf err;
  upb_Status* status;
  upb_Arena* arena;
} jsonenc;

static void jsonenc_msg(jsonenc* e, const upb_Message* msg,
                        const upb_MessageDef* m);
static void jsonenc_scalar(jsonenc* e, upb_MessageValue val,
                           const upb_FieldDef* f);
static void jsonenc_msgfield(jsonenc* e, const upb_Message* msg,
                             const upb_MessageDef* m);
static void jsonenc_msgfields(jsonenc* e, const upb_Message* msg,
                              const upb_MessageDef* m, bool first);
static void jsonenc_value(jsonenc* e, const upb_Message* msg,
                          const upb_MessageDef* m);

UPB_NORETURN static void jsonenc_err(jsonenc* e, const char* msg) {
  upb_Status_SetErrorMessage(e->status, msg);
  UPB_LONGJMP(e->err, 1);
}

UPB_PRINTF(2, 3)
UPB_NORETURN static void jsonenc_errf(jsonenc* e, const char* fmt, ...) {
  va_list argp;
  va_start(argp, fmt);
  upb_Status_VSetErrorFormat(e->status, fmt, argp);
  va_end(argp);
  UPB_LONGJMP(e->err, 1);
}

static upb_Arena* jsonenc_arena(jsonenc* e) {
  /* Create lazily, since it's only needed for Any */
  if (!e->arena) {
    e->arena = upb_Arena_New();
  }
  return e->arena;
}

static void jsonenc_putbytes(jsonenc* e, const void* data, size_t len) {
  size_t have = e->end - e->ptr;
  if (UPB_LIKELY(have >= len)) {
    memcpy(e->ptr, data, len);
    e->ptr += len;
  } else {
    if (have) {
      memcpy(e->ptr, data, have);
      e->ptr += have;
    }
    e->overflow += (len - have);
  }
}

static void jsonenc_putstr(jsonenc* e, const char* str) {
  jsonenc_putbytes(e, str, strlen(str));
}

UPB_PRINTF(2, 3)
static void jsonenc_printf(jsonenc* e, const char* fmt, ...) {
  size_t n;
  size_t have = e->end - e->ptr;
  va_list args;

  va_start(args, fmt);
  n = _upb_vsnprintf(e->ptr, have, fmt, args);
  va_end(args);

  if (UPB_LIKELY(have > n)) {
    e->ptr += n;
  } else {
    e->ptr = UPB_PTRADD(e->ptr, have);
    e->overflow += (n - have);
  }
}

static void jsonenc_nanos(jsonenc* e, int32_t nanos) {
  int digits = 9;

  if (nanos == 0) return;
  if (nanos < 0 || nanos >= 1000000000) {
    jsonenc_err(e, "error formatting timestamp as JSON: invalid nanos");
  }

  while (nanos % 1000 == 0) {
    nanos /= 1000;
    digits -= 3;
  }

  jsonenc_printf(e, ".%.*" PRId32, digits, nanos);
}

static void jsonenc_timestamp(jsonenc* e, const upb_Message* msg,
                              const upb_MessageDef* m) {
  const upb_FieldDef* seconds_f = upb_MessageDef_FindFieldByNumber(m, 1);
  const upb_FieldDef* nanos_f = upb_MessageDef_FindFieldByNumber(m, 2);
  int64_t seconds = upb_Message_GetFieldByDef(msg, seconds_f).int64_val;
  int32_t nanos = upb_Message_GetFieldByDef(msg, nanos_f).int32_val;
  int L, N, I, J, K, hour, min, sec;

  if (seconds < -62135596800) {
    jsonenc_err(e,
                "error formatting timestamp as JSON: minimum acceptable value "
                "is 0001-01-01T00:00:00Z");
  } else if (seconds > 253402300799) {
    jsonenc_err(e,
                "error formatting timestamp as JSON: maximum acceptable value "
                "is 9999-12-31T23:59:59Z");
  }

  /* Julian Day -> Y/M/D, Algorithm from:
   * Fliegel, H. F., and Van Flandern, T. C., "A Machine Algorithm for
   *   Processing Calendar Dates," Communications of the Association of
   *   Computing Machines, vol. 11 (1968), p. 657.  */
  seconds += 62135596800;  // Ensure seconds is positive.
  L = (int)(seconds / 86400) - 719162 + 68569 + 2440588;
  N = 4 * L / 146097;
  L = L - (146097 * N + 3) / 4;
  I = 4000 * (L + 1) / 1461001;
  L = L - 1461 * I / 4 + 31;
  J = 80 * L / 2447;
  K = L - 2447 * J / 80;
  L = J / 11;
  J = J + 2 - 12 * L;
  I = 100 * (N - 49) + I + L;

  sec = seconds % 60;
  min = (seconds / 60) % 60;
  hour = (seconds / 3600) % 24;

  jsonenc_printf(e, "\"%04d-%02d-%02dT%02d:%02d:%02d", I, J, K, hour, min, sec);
  jsonenc_nanos(e, nanos);
  jsonenc_putstr(e, "Z\"");
}

static void jsonenc_duration(jsonenc* e, const upb_Message* msg,
                             const upb_MessageDef* m) {
  const upb_FieldDef* seconds_f = upb_MessageDef_FindFieldByNumber(m, 1);
  const upb_FieldDef* nanos_f = upb_MessageDef_FindFieldByNumber(m, 2);
  int64_t seconds = upb_Message_GetFieldByDef(msg, seconds_f).int64_val;
  int32_t nanos = upb_Message_GetFieldByDef(msg, nanos_f).int32_val;
  bool negative = false;

  if (seconds > 315576000000 || seconds < -315576000000 ||
      (seconds != 0 && nanos != 0 && (seconds < 0) != (nanos < 0))) {
    jsonenc_err(e, "bad duration");
  }

  if (seconds < 0) {
    negative = true;
    seconds = -seconds;
  }
  if (nanos < 0) {
    negative = true;
    nanos = -nanos;
  }

  jsonenc_putstr(e, "\"");
  if (negative) {
    jsonenc_putstr(e, "-");
  }
  jsonenc_printf(e, "%" PRId64, seconds);
  jsonenc_nanos(e, nanos);
  jsonenc_putstr(e, "s\"");
}

static void jsonenc_enum(int32_t val, const upb_FieldDef* f, jsonenc* e) {
  const upb_EnumDef* e_def = upb_FieldDef_EnumSubDef(f);

  if (strcmp(upb_EnumDef_FullName(e_def), "google.protobuf.NullValue") == 0) {
    jsonenc_putstr(e, "null");
  } else {
    const upb_EnumValueDef* ev =
        (e->options & upb_JsonEncode_FormatEnumsAsIntegers)
            ? NULL
            : upb_EnumDef_FindValueByNumber(e_def, val);

    if (ev) {
      jsonenc_printf(e, "\"%s\"", upb_EnumValueDef_Name(ev));
    } else {
      jsonenc_printf(e, "%" PRId32, val);
    }
  }
}

static void jsonenc_bytes(jsonenc* e, upb_StringView str) {
  /* This is the regular base64, not the "web-safe" version. */
  static const char base64[] =
      "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
  const unsigned char* ptr = (unsigned char*)str.data;
  const unsigned char* end = UPB_PTRADD(ptr, str.size);
  char buf[4];

  jsonenc_putstr(e, "\"");

  while (end - ptr >= 3) {
    buf[0] = base64[ptr[0] >> 2];
    buf[1] = base64[((ptr[0] & 0x3) << 4) | (ptr[1] >> 4)];
    buf[2] = base64[((ptr[1] & 0xf) << 2) | (ptr[2] >> 6)];
    buf[3] = base64[ptr[2] & 0x3f];
    jsonenc_putbytes(e, buf, 4);
    ptr += 3;
  }

  switch (end - ptr) {
    case 2:
      buf[0] = base64[ptr[0] >> 2];
      buf[1] = base64[((ptr[0] & 0x3) << 4) | (ptr[1] >> 4)];
      buf[2] = base64[(ptr[1] & 0xf) << 2];
      buf[3] = '=';
      jsonenc_putbytes(e, buf, 4);
      break;
    case 1:
      buf[0] = base64[ptr[0] >> 2];
      buf[1] = base64[((ptr[0] & 0x3) << 4)];
      buf[2] = '=';
      buf[3] = '=';
      jsonenc_putbytes(e, buf, 4);
      break;
  }

  jsonenc_putstr(e, "\"");
}

static void jsonenc_stringbody(jsonenc* e, upb_StringView str) {
  const char* ptr = str.data;
  const char* end = UPB_PTRADD(ptr, str.size);

  while (ptr < end) {
    switch (*ptr) {
      case '\n':
        jsonenc_putstr(e, "\\n");
        break;
      case '\r':
        jsonenc_putstr(e, "\\r");
        break;
      case '\t':
        jsonenc_putstr(e, "\\t");
        break;
      case '\"':
        jsonenc_putstr(e, "\\\"");
        break;
      case '\f':
        jsonenc_putstr(e, "\\f");
        break;
      case '\b':
        jsonenc_putstr(e, "\\b");
        break;
      case '\\':
        jsonenc_putstr(e, "\\\\");
        break;
      default:
        if ((uint8_t)*ptr < 0x20) {
          jsonenc_printf(e, "\\u%04x", (int)(uint8_t)*ptr);
        } else {
          /* This could be a non-ASCII byte.  We rely on the string being valid
           * UTF-8. */
          jsonenc_putbytes(e, ptr, 1);
        }
        break;
    }
    ptr++;
  }
}

static void jsonenc_string(jsonenc* e, upb_StringView str) {
  jsonenc_putstr(e, "\"");
  jsonenc_stringbody(e, str);
  jsonenc_putstr(e, "\"");
}

static bool upb_JsonEncode_HandleSpecialDoubles(jsonenc* e, double val) {
  if (val == INFINITY) {
    jsonenc_putstr(e, "\"Infinity\"");
  } else if (val == -INFINITY) {
    jsonenc_putstr(e, "\"-Infinity\"");
  } else if (val != val) {
    jsonenc_putstr(e, "\"NaN\"");
  } else {
    return false;
  }
  return true;
}

static void upb_JsonEncode_Double(jsonenc* e, double val) {
  if (upb_JsonEncode_HandleSpecialDoubles(e, val)) return;
  char buf[32];
  _upb_EncodeRoundTripDouble(val, buf, sizeof(buf));
  jsonenc_putstr(e, buf);
}

static void upb_JsonEncode_Float(jsonenc* e, float val) {
  if (upb_JsonEncode_HandleSpecialDoubles(e, val)) return;
  char buf[32];
  _upb_EncodeRoundTripFloat(val, buf, sizeof(buf));
  jsonenc_putstr(e, buf);
}

static void jsonenc_wrapper(jsonenc* e, const upb_Message* msg,
                            const upb_MessageDef* m) {
  const upb_FieldDef* val_f = upb_MessageDef_FindFieldByNumber(m, 1);
  upb_MessageValue val = upb_Message_GetFieldByDef(msg, val_f);
  jsonenc_scalar(e, val, val_f);
}

static const upb_MessageDef* jsonenc_getanymsg(jsonenc* e,
                                               upb_StringView type_url) {
  /* Find last '/', if any. */
  const char* end = type_url.data + type_url.size;
  const char* ptr = end;
  const upb_MessageDef* ret;

  if (!e->ext_pool) {
    jsonenc_err(e, "Tried to encode Any, but no symtab was provided");
  }

  if (type_url.size == 0) goto badurl;

  while (true) {
    if (--ptr == type_url.data) {
      /* Type URL must contain at least one '/', with host before. */
      goto badurl;
    }
    if (*ptr == '/') {
      ptr++;
      break;
    }
  }

  ret = upb_DefPool_FindMessageByNameWithSize(e->ext_pool, ptr, end - ptr);

  if (!ret) {
    jsonenc_errf(e, "Couldn't find Any type: %.*s", (int)(end - ptr), ptr);
  }

  return ret;

badurl:
  jsonenc_errf(e, "Bad type URL: " UPB_STRINGVIEW_FORMAT,
               UPB_STRINGVIEW_ARGS(type_url));
}

static void jsonenc_any(jsonenc* e, const upb_Message* msg,
                        const upb_MessageDef* m) {
  const upb_FieldDef* type_url_f = upb_MessageDef_FindFieldByNumber(m, 1);
  const upb_FieldDef* value_f = upb_MessageDef_FindFieldByNumber(m, 2);
  upb_StringView type_url = upb_Message_GetFieldByDef(msg, type_url_f).str_val;
  upb_StringView value = upb_Message_GetFieldByDef(msg, value_f).str_val;
  const upb_MessageDef* any_m = jsonenc_getanymsg(e, type_url);
  const upb_MiniTable* any_layout = upb_MessageDef_MiniTable(any_m);
  upb_Arena* arena = jsonenc_arena(e);
  upb_Message* any = upb_Message_New(any_layout, arena);

  if (upb_Decode(value.data, value.size, any, any_layout, NULL, 0, arena) !=
      kUpb_DecodeStatus_Ok) {
    jsonenc_err(e, "Error decoding message in Any");
  }

  jsonenc_putstr(e, "{\"@type\":");
  jsonenc_string(e, type_url);

  if (upb_MessageDef_WellKnownType(any_m) == kUpb_WellKnown_Unspecified) {
    /* Regular messages: {"@type": "...","foo": 1, "bar": 2} */
    jsonenc_msgfields(e, any, any_m, false);
  } else {
    /* Well-known type: {"@type": "...","value": <well-known encoding>} */
    jsonenc_putstr(e, ",\"value\":");
    jsonenc_msgfield(e, any, any_m);
  }

  jsonenc_putstr(e, "}");
}

static void jsonenc_putsep(jsonenc* e, const char* str, bool* first) {
  if (*first) {
    *first = false;
  } else {
    jsonenc_putstr(e, str);
  }
}

static void jsonenc_fieldpath(jsonenc* e, upb_StringView path) {
  const char* ptr = path.data;
  const char* end = ptr + path.size;

  while (ptr < end) {
    char ch = *ptr;

    if (ch >= 'A' && ch <= 'Z') {
      jsonenc_err(e, "Field mask element may not have upper-case letter.");
    } else if (ch == '_') {
      if (ptr == end - 1 || *(ptr + 1) < 'a' || *(ptr + 1) > 'z') {
        jsonenc_err(e, "Underscore must be followed by a lowercase letter.");
      }
      ch = *++ptr - 32;
    }

    jsonenc_putbytes(e, &ch, 1);
    ptr++;
  }
}

static void jsonenc_fieldmask(jsonenc* e, const upb_Message* msg,
                              const upb_MessageDef* m) {
  const upb_FieldDef* paths_f = upb_MessageDef_FindFieldByNumber(m, 1);
  const upb_Array* paths = upb_Message_GetFieldByDef(msg, paths_f).array_val;
  bool first = true;
  size_t i, n = 0;

  if (paths) n = upb_Array_Size(paths);

  jsonenc_putstr(e, "\"");

  for (i = 0; i < n; i++) {
    jsonenc_putsep(e, ",", &first);
    jsonenc_fieldpath(e, upb_Array_Get(paths, i).str_val);
  }

  jsonenc_putstr(e, "\"");
}

static void jsonenc_struct(jsonenc* e, const upb_Message* msg,
                           const upb_MessageDef* m) {
  jsonenc_putstr(e, "{");

  const upb_FieldDef* fields_f = upb_MessageDef_FindFieldByNumber(m, 1);
  const upb_Map* fields = upb_Message_GetFieldByDef(msg, fields_f).map_val;

  if (fields) {
    const upb_MessageDef* entry_m = upb_FieldDef_MessageSubDef(fields_f);
    const upb_FieldDef* value_f = upb_MessageDef_FindFieldByNumber(entry_m, 2);

    size_t iter = kUpb_Map_Begin;
    bool first = true;

    upb_MessageValue key, val;
    while (upb_Map_Next(fields, &key, &val, &iter)) {
      jsonenc_putsep(e, ",", &first);
      jsonenc_string(e, key.str_val);
      jsonenc_putstr(e, ":");
      jsonenc_value(e, val.msg_val, upb_FieldDef_MessageSubDef(value_f));
    }
  }

  jsonenc_putstr(e, "}");
}

static void jsonenc_listvalue(jsonenc* e, const upb_Message* msg,
                              const upb_MessageDef* m) {
  const upb_FieldDef* values_f = upb_MessageDef_FindFieldByNumber(m, 1);
  const upb_MessageDef* values_m = upb_FieldDef_MessageSubDef(values_f);
  const upb_Array* values = upb_Message_GetFieldByDef(msg, values_f).array_val;
  size_t i;
  bool first = true;

  jsonenc_putstr(e, "[");

  if (values) {
    const size_t size = upb_Array_Size(values);
    for (i = 0; i < size; i++) {
      upb_MessageValue elem = upb_Array_Get(values, i);

      jsonenc_putsep(e, ",", &first);
      jsonenc_value(e, elem.msg_val, values_m);
    }
  }

  jsonenc_putstr(e, "]");
}

static void jsonenc_value(jsonenc* e, const upb_Message* msg,
                          const upb_MessageDef* m) {
  /* TODO: do we want a reflection method to get oneof case? */
  size_t iter = kUpb_Message_Begin;
  const upb_FieldDef* f;
  upb_MessageValue val;

  if (!upb_Message_Next(msg, m, NULL, &f, &val, &iter)) {
    jsonenc_err(e, "No value set in Value proto");
  }

  switch (upb_FieldDef_Number(f)) {
    case 1:
      jsonenc_putstr(e, "null");
      break;
    case 2:
      if (upb_JsonEncode_HandleSpecialDoubles(e, val.double_val)) {
        jsonenc_err(
            e,
            "google.protobuf.Value cannot encode double values for "
            "infinity or nan, because they would be parsed as a string");
      }
      upb_JsonEncode_Double(e, val.double_val);
      break;
    case 3:
      jsonenc_string(e, val.str_val);
      break;
    case 4:
      jsonenc_putstr(e, val.bool_val ? "true" : "false");
      break;
    case 5:
      jsonenc_struct(e, val.msg_val, upb_FieldDef_MessageSubDef(f));
      break;
    case 6:
      jsonenc_listvalue(e, val.msg_val, upb_FieldDef_MessageSubDef(f));
      break;
  }
}

static void jsonenc_msgfield(jsonenc* e, const upb_Message* msg,
                             const upb_MessageDef* m) {
  switch (upb_MessageDef_WellKnownType(m)) {
    case kUpb_WellKnown_Unspecified:
      jsonenc_msg(e, msg, m);
      break;
    case kUpb_WellKnown_Any:
      jsonenc_any(e, msg, m);
      break;
    case kUpb_WellKnown_FieldMask:
      jsonenc_fieldmask(e, msg, m);
      break;
    case kUpb_WellKnown_Duration:
      jsonenc_duration(e, msg, m);
      break;
    case kUpb_WellKnown_Timestamp:
      jsonenc_timestamp(e, msg, m);
      break;
    case kUpb_WellKnown_DoubleValue:
    case kUpb_WellKnown_FloatValue:
    case kUpb_WellKnown_Int64Value:
    case kUpb_WellKnown_UInt64Value:
    case kUpb_WellKnown_Int32Value:
    case kUpb_WellKnown_UInt32Value:
    case kUpb_WellKnown_StringValue:
    case kUpb_WellKnown_BytesValue:
    case kUpb_WellKnown_BoolValue:
      jsonenc_wrapper(e, msg, m);
      break;
    case kUpb_WellKnown_Value:
      jsonenc_value(e, msg, m);
      break;
    case kUpb_WellKnown_ListValue:
      jsonenc_listvalue(e, msg, m);
      break;
    case kUpb_WellKnown_Struct:
      jsonenc_struct(e, msg, m);
      break;
  }
}

static void jsonenc_scalar(jsonenc* e, upb_MessageValue val,
                           const upb_FieldDef* f) {
  switch (upb_FieldDef_CType(f)) {
    case kUpb_CType_Bool:
      jsonenc_putstr(e, val.bool_val ? "true" : "false");
      break;
    case kUpb_CType_Float:
      upb_JsonEncode_Float(e, val.float_val);
      break;
    case kUpb_CType_Double:
      upb_JsonEncode_Double(e, val.double_val);
      break;
    case kUpb_CType_Int32:
      jsonenc_printf(e, "%" PRId32, val.int32_val);
      break;
    case kUpb_CType_UInt32:
      jsonenc_printf(e, "%" PRIu32, val.uint32_val);
      break;
    case kUpb_CType_Int64:
      jsonenc_printf(e, "\"%" PRId64 "\"", val.int64_val);
      break;
    case kUpb_CType_UInt64:
      jsonenc_printf(e, "\"%" PRIu64 "\"", val.uint64_val);
      break;
    case kUpb_CType_String:
      jsonenc_string(e, val.str_val);
      break;
    case kUpb_CType_Bytes:
      jsonenc_bytes(e, val.str_val);
      break;
    case kUpb_CType_Enum:
      jsonenc_enum(val.int32_val, f, e);
      break;
    case kUpb_CType_Message:
      jsonenc_msgfield(e, val.msg_val, upb_FieldDef_MessageSubDef(f));
      break;
  }
}

static void jsonenc_mapkey(jsonenc* e, upb_MessageValue val,
                           const upb_FieldDef* f) {
  jsonenc_putstr(e, "\"");

  switch (upb_FieldDef_CType(f)) {
    case kUpb_CType_Bool:
      jsonenc_putstr(e, val.bool_val ? "true" : "false");
      break;
    case kUpb_CType_Int32:
      jsonenc_printf(e, "%" PRId32, val.int32_val);
      break;
    case kUpb_CType_UInt32:
      jsonenc_printf(e, "%" PRIu32, val.uint32_val);
      break;
    case kUpb_CType_Int64:
      jsonenc_printf(e, "%" PRId64, val.int64_val);
      break;
    case kUpb_CType_UInt64:
      jsonenc_printf(e, "%" PRIu64, val.uint64_val);
      break;
    case kUpb_CType_String:
      jsonenc_stringbody(e, val.str_val);
      break;
    default:
      UPB_UNREACHABLE();
  }

  jsonenc_putstr(e, "\":");
}

static void jsonenc_array(jsonenc* e, const upb_Array* arr,
                          const upb_FieldDef* f) {
  size_t i;
  size_t size = arr ? upb_Array_Size(arr) : 0;
  bool first = true;

  jsonenc_putstr(e, "[");

  for (i = 0; i < size; i++) {
    jsonenc_putsep(e, ",", &first);
    jsonenc_scalar(e, upb_Array_Get(arr, i), f);
  }

  jsonenc_putstr(e, "]");
}

static void jsonenc_map(jsonenc* e, const upb_Map* map, const upb_FieldDef* f) {
  jsonenc_putstr(e, "{");

  const upb_MessageDef* entry = upb_FieldDef_MessageSubDef(f);
  const upb_FieldDef* key_f = upb_MessageDef_FindFieldByNumber(entry, 1);
  const upb_FieldDef* val_f = upb_MessageDef_FindFieldByNumber(entry, 2);

  if (map) {
    size_t iter = kUpb_Map_Begin;
    bool first = true;

    upb_MessageValue key, val;
    while (upb_Map_Next(map, &key, &val, &iter)) {
      jsonenc_putsep(e, ",", &first);
      jsonenc_mapkey(e, key, key_f);
      jsonenc_scalar(e, val, val_f);
    }
  }

  jsonenc_putstr(e, "}");
}

static void jsonenc_fieldval(jsonenc* e, const upb_FieldDef* f,
                             upb_MessageValue val, bool* first) {
  const char* name;

  jsonenc_putsep(e, ",", first);

  if (upb_FieldDef_IsExtension(f)) {
    // TODO: For MessageSet, I would have expected this to print the message
    // name here, but Python doesn't appear to do this. We should do more
    // research here about what various implementations do.
    jsonenc_printf(e, "\"[%s]\":", upb_FieldDef_FullName(f));
  } else {
    if (e->options & upb_JsonEncode_UseProtoNames) {
      name = upb_FieldDef_Name(f);
    } else {
      name = upb_FieldDef_JsonName(f);
    }
    jsonenc_printf(e, "\"%s\":", name);
  }

  if (upb_FieldDef_IsMap(f)) {
    jsonenc_map(e, val.map_val, f);
  } else if (upb_FieldDef_IsRepeated(f)) {
    jsonenc_array(e, val.array_val, f);
  } else {
    jsonenc_scalar(e, val, f);
  }
}

static void jsonenc_msgfields(jsonenc* e, const upb_Message* msg,
                              const upb_MessageDef* m, bool first) {
  upb_MessageValue val;
  const upb_FieldDef* f;

  if (e->options & upb_JsonEncode_EmitDefaults) {
    /* Iterate over all fields. */
    int i = 0;
    int n = upb_MessageDef_FieldCount(m);
    for (i = 0; i < n; i++) {
      f = upb_MessageDef_Field(m, i);
      if (!upb_FieldDef_HasPresence(f) || upb_Message_HasFieldByDef(msg, f)) {
        jsonenc_fieldval(e, f, upb_Message_GetFieldByDef(msg, f), &first);
      }
    }
  } else {
    /* Iterate over non-empty fields. */
    size_t iter = kUpb_Message_Begin;
    while (upb_Message_Next(msg, m, e->ext_pool, &f, &val, &iter)) {
      jsonenc_fieldval(e, f, val, &first);
    }
  }
}

static void jsonenc_msg(jsonenc* e, const upb_Message* msg,
                        const upb_MessageDef* m) {
  jsonenc_putstr(e, "{");
  jsonenc_msgfields(e, msg, m, true);
  jsonenc_putstr(e, "}");
}

static size_t jsonenc_nullz(jsonenc* e, size_t size) {
  size_t ret = e->ptr - e->buf + e->overflow;

  if (size > 0) {
    if (e->ptr == e->end) e->ptr--;
    *e->ptr = '\0';
  }

  return ret;
}

static size_t upb_JsonEncoder_Encode(jsonenc* const e,
                                     const upb_Message* const msg,
                                     const upb_MessageDef* const m,
                                     const size_t size) {
  if (UPB_SETJMP(e->err) != 0) return -1;

  jsonenc_msgfield(e, msg, m);
  if (e->arena) upb_Arena_Free(e->arena);
  return jsonenc_nullz(e, size);
}

size_t upb_JsonEncode(const upb_Message* msg, const upb_MessageDef* m,
                      const upb_DefPool* ext_pool, int options, char* buf,
                      size_t size, upb_Status* status) {
  jsonenc e;

  e.buf = buf;
  e.ptr = buf;
  e.end = UPB_PTRADD(buf, size);
  e.overflow = 0;
  e.options = options;
  e.ext_pool = ext_pool;
  e.status = status;
  e.arena = NULL;

  return upb_JsonEncoder_Encode(&e, msg, m, size);
}


// Must be last.

const char* upb_BufToUint64(const char* ptr, const char* end, uint64_t* val) {
  uint64_t u64 = 0;
  while (ptr < end) {
    unsigned ch = *ptr - '0';
    if (ch >= 10) break;
    if (u64 > UINT64_MAX / 10 || u64 * 10 > UINT64_MAX - ch) {
      return NULL;  // integer overflow
    }
    u64 *= 10;
    u64 += ch;
    ptr++;
  }

  *val = u64;
  return ptr;
}

const char* upb_BufToInt64(const char* ptr, const char* end, int64_t* val,
                           bool* is_neg) {
  bool neg = false;
  uint64_t u64;

  if (ptr != end && *ptr == '-') {
    ptr++;
    neg = true;
  }

  ptr = upb_BufToUint64(ptr, end, &u64);
  if (!ptr || u64 > (uint64_t)INT64_MAX + neg) {
    return NULL;  // integer overflow
  }

  *val = neg ? -u64 : u64;
  if (is_neg) *is_neg = neg;
  return ptr;
}


#include <float.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>

// Must be last.

/* Miscellaneous utilities ****************************************************/

static void upb_FixLocale(char* p) {
  /* printf() is dependent on locales; sadly there is no easy and portable way
   * to avoid this. This little post-processing step will translate 1,2 -> 1.2
   * since JSON needs the latter. Arguably a hack, but it is simple and the
   * alternatives are far more complicated, platform-dependent, and/or larger
   * in code size. */
  for (; *p; p++) {
    if (*p == ',') *p = '.';
  }
}

void _upb_EncodeRoundTripDouble(double val, char* buf, size_t size) {
  assert(size >= kUpb_RoundTripBufferSize);
  if (isnan(val)) {
    snprintf(buf, size, "%s", "nan");
    return;
  }
  snprintf(buf, size, "%.*g", DBL_DIG, val);
  if (strtod(buf, NULL) != val) {
    snprintf(buf, size, "%.*g", DBL_DIG + 2, val);
    assert(strtod(buf, NULL) == val);
  }
  upb_FixLocale(buf);
}

void _upb_EncodeRoundTripFloat(float val, char* buf, size_t size) {
  assert(size >= kUpb_RoundTripBufferSize);
  if (isnan(val)) {
    snprintf(buf, size, "%s", "nan");
    return;
  }
  snprintf(buf, size, "%.*g", FLT_DIG, val);
  if (strtof(buf, NULL) != val) {
    snprintf(buf, size, "%.*g", FLT_DIG + 3, val);
    assert(strtof(buf, NULL) == val);
  }
  upb_FixLocale(buf);
}


#include <stdlib.h>
#include <string.h>

// Must be last.

// Determine the locale-specific radix character by calling sprintf() to print
// the number 1.5, then stripping off the digits.  As far as I can tell, this
// is the only portable, thread-safe way to get the C library to divulge the
// locale's radix character.  No, localeconv() is NOT thread-safe.

static int GetLocaleRadix(char *data, size_t capacity) {
  char temp[16];
  const int size = snprintf(temp, sizeof(temp), "%.1f", 1.5);
  UPB_ASSERT(temp[0] == '1');
  UPB_ASSERT(temp[size - 1] == '5');
  if (size < capacity) {
    return 0;
  }
  temp[size - 1] = '\0';
  strncpy(data, temp + 1, size);
  return size - 2;
}

// Populates a string identical to *input except that the character pointed to
// by pos (which should be '.') is replaced with the locale-specific radix.

static void LocalizeRadix(const char *input, const char *pos, char *output,
                          int output_size) {
  const int len1 = pos - input;

  char radix[8];
  const int len2 = GetLocaleRadix(radix, sizeof(radix));

  const int n = output_size - len1 - len2 - 1;
  if (n < 0) {
    return;
  }

  memcpy(output, input, len1);
  memcpy(output + len1, radix, len2);
  strncpy(output + len1 + len2, input + len1 + 1, n);
  output[output_size - 1] = '\0';
}

double _upb_NoLocaleStrtod(const char *str, char **endptr) {
  // We cannot simply set the locale to "C" temporarily with setlocale()
  // as this is not thread-safe.  Instead, we try to parse in the current
  // locale first.  If parsing stops at a '.' character, then this is a
  // pretty good hint that we're actually in some other locale in which
  // '.' is not the radix character.

  char *temp_endptr;
  double result = strtod(str, &temp_endptr);
  if (endptr != NULL) *endptr = temp_endptr;
  if (*temp_endptr != '.') return result;

  // Parsing halted on a '.'.  Perhaps we're in a different locale?  Let's
  // try to replace the '.' with a locale-specific radix character and
  // try again.

  char localized[80];
  LocalizeRadix(str, temp_endptr, localized, sizeof localized);
  char *localized_endptr;
  result = strtod(localized, &localized_endptr);
  if ((localized_endptr - &localized[0]) > (temp_endptr - str)) {
    // This attempt got further, so replacing the decimal must have helped.
    // Update endptr to point at the right location.
    if (endptr != NULL) {
      // size_diff is non-zero if the localized radix has multiple bytes.
      int size_diff = strlen(localized) - strlen(str);
      *endptr = (char *)str + (localized_endptr - &localized[0] - size_diff);
    }
  }

  return result;
}


// Must be last.

int upb_Unicode_ToUTF8(uint32_t cp, char* out) {
  if (cp <= 0x7f) {
    out[0] = cp;
    return 1;
  }
  if (cp <= 0x07ff) {
    out[0] = (cp >> 6) | 0xc0;
    out[1] = (cp & 0x3f) | 0x80;
    return 2;
  }
  if (cp <= 0xffff) {
    out[0] = (cp >> 12) | 0xe0;
    out[1] = ((cp >> 6) & 0x3f) | 0x80;
    out[2] = (cp & 0x3f) | 0x80;
    return 3;
  }
  if (cp <= 0x10ffff) {
    out[0] = (cp >> 18) | 0xf0;
    out[1] = ((cp >> 12) & 0x3f) | 0x80;
    out[2] = ((cp >> 6) & 0x3f) | 0x80;
    out[3] = (cp & 0x3f) | 0x80;
    return 4;
  }
  return 0;
}


#include <stdlib.h>

// Must be last.

static void* upb_global_allocfunc(upb_alloc* alloc, void* ptr, size_t oldsize,
                                  size_t size, size_t* actual_size) {
  UPB_UNUSED(alloc);
  UPB_UNUSED(oldsize);
  UPB_UNUSED(actual_size);
  if (size == 0) {
    free(ptr);
    return NULL;
  } else {
    return realloc(ptr, size);
  }
}

upb_alloc upb_alloc_global = {&upb_global_allocfunc};


#include <string.h>


#ifdef UPB_TRACING_ENABLED
#include <stdatomic.h>
#endif

#include <stddef.h>
#include <stdint.h>


// Must be last.

static UPB_ATOMIC(size_t) g_max_block_size = UPB_DEFAULT_MAX_BLOCK_SIZE;

void upb_Arena_SetMaxBlockSize(size_t max) {
  UPB_ASSERT(max <= UINT32_MAX);
  upb_Atomic_Store(&g_max_block_size, max, memory_order_relaxed);
}

typedef struct upb_MemBlock {
  struct upb_MemBlock* next;
  // Size of the actual allocation.
  // Size of 0 means this is a upb_ArenaRef.
  size_t size;
  // Data follows.
} upb_MemBlock;

// A special block type that indicates a reference to another arena.
// When this arena is freed, a ref is released on the referenced arena.
// size must be 0.
typedef struct upb_ArenaRef {
  upb_MemBlock prefix;  // size is always zero
  const upb_Arena* arena;
#ifndef NDEBUG
  const struct upb_ArenaRef* next_ref;
#endif
} upb_ArenaRef;

typedef struct upb_ArenaInternal {
  // upb_alloc* together with a low bit which signals if there is an initial
  // block.
  uintptr_t block_alloc;

  // Linked list of blocks to free/cleanup.
  upb_MemBlock* blocks;

#ifndef NDEBUG
  // Stack of pointers to other arenas that this arena owns.
  // Used for debug-only ref cycle checks.
  UPB_ATOMIC(const upb_ArenaRef*) refs;
#endif

  // Size of the last block we allocated in the normal exponential scheme.
  uint32_t last_block_size;

  // A hint that grows whenever we perform a "one-off" allocation into a a
  // dedicated block. This helps us determine if these outlier blocks are
  // actually common enough that we should switch back to the normal exponential
  // scheme at the larger size.
  uint32_t size_hint;

  // All non atomic members used during allocation must be above this point, and
  // are used by _SwapIn/_SwapOut

  // Total space allocated in blocks, atomic only for SpaceAllocated
  UPB_ATOMIC(uintptr_t) space_allocated;

  // The cleanup for the allocator. This is called after all the blocks are
  // freed in an arena.
  upb_AllocCleanupFunc* upb_alloc_cleanup;

  // When multiple arenas are fused together, each arena points to a parent
  // arena (root points to itself). The root tracks how many live arenas
  // reference it.

  // The low bit is tagged:
  //   0: pointer to parent
  //   1: count, left shifted by one
  UPB_ATOMIC(uintptr_t) parent_or_count;

  // All nodes that are fused together are in a singly-linked list.
  // == NULL at end of list.
  UPB_ATOMIC(struct upb_ArenaInternal*) next;

  // - If the low bit is set, is a pointer to the tail of the list (populated
  //   for roots, set to self for roots with no fused arenas). This is best
  //   effort, and it may not always reflect the true tail, but it will always
  //   be a valid node in the list. This is useful for finding the list tail
  //   without having to walk the entire list.
  // - If the low bit is not set, is a pointer to the previous node in the list,
  //   such that a->previous_or_tail->next == a.
  UPB_ATOMIC(uintptr_t) previous_or_tail;

  // We use a different UPB_XSAN_MEMBER than the one in upb_Arena because the
  // two are distinct synchronization domains.  The upb_Arena.ptr member is
  // not published in the allocation path, so it is not synchronized with
  // respect to operations performed in this file such as Fuse, Free,
  // SpaceAllocated, etc.  This means that it is not safe to read or write
  // the upb_Arena.ptr member in those functions.
  UPB_XSAN_MEMBER
} upb_ArenaInternal;

// All public + private state for an arena.
typedef struct {
  upb_Arena head;
  upb_ArenaInternal body;
} upb_ArenaState;

typedef struct {
  upb_ArenaInternal* root;
  uintptr_t tagged_count;
} upb_ArenaRoot;

static const size_t kUpb_MemblockReserve =
    UPB_ALIGN_MALLOC(sizeof(upb_MemBlock));

static const size_t kUpb_ArenaRefReserve =
    UPB_ALIGN_MALLOC(sizeof(upb_ArenaRef));

// Extracts the (upb_ArenaInternal*) from a (upb_Arena*)
static upb_ArenaInternal* upb_Arena_Internal(const upb_Arena* a) {
  return &((upb_ArenaState*)a)->body;
}

static bool _upb_Arena_IsTaggedRefcount(uintptr_t parent_or_count) {
  return (parent_or_count & 1) == 1;
}

static bool _upb_Arena_IsTaggedPointer(uintptr_t parent_or_count) {
  return (parent_or_count & 1) == 0;
}

static uintptr_t _upb_Arena_RefCountFromTagged(uintptr_t parent_or_count) {
  UPB_ASSERT(_upb_Arena_IsTaggedRefcount(parent_or_count));
  return parent_or_count >> 1;
}

static uintptr_t _upb_Arena_TaggedFromRefcount(uintptr_t refcount) {
  uintptr_t parent_or_count = (refcount << 1) | 1;
  UPB_ASSERT(_upb_Arena_IsTaggedRefcount(parent_or_count));
  return parent_or_count;
}

static upb_ArenaInternal* _upb_Arena_PointerFromTagged(
    uintptr_t parent_or_count) {
  UPB_ASSERT(_upb_Arena_IsTaggedPointer(parent_or_count));
  return (upb_ArenaInternal*)parent_or_count;
}

static uintptr_t _upb_Arena_TaggedFromPointer(upb_ArenaInternal* ai) {
  uintptr_t parent_or_count = (uintptr_t)ai;
  UPB_ASSERT(_upb_Arena_IsTaggedPointer(parent_or_count));
  return parent_or_count;
}

static bool _upb_Arena_IsTaggedTail(uintptr_t previous_or_tail) {
  return (previous_or_tail & 1) == 1;
}

static bool _upb_Arena_IsTaggedPrevious(uintptr_t previous_or_tail) {
  return (previous_or_tail & 1) == 0;
}

static upb_ArenaInternal* _upb_Arena_TailFromTagged(
    uintptr_t previous_or_tail) {
  UPB_ASSERT(_upb_Arena_IsTaggedTail(previous_or_tail));
  return (upb_ArenaInternal*)(previous_or_tail ^ 1);
}

static uintptr_t _upb_Arena_TaggedFromTail(upb_ArenaInternal* tail) {
  uintptr_t previous_or_tail = (uintptr_t)tail | 1;
  UPB_ASSERT(_upb_Arena_IsTaggedTail(previous_or_tail));
  return previous_or_tail;
}

static upb_ArenaInternal* _upb_Arena_PreviousFromTagged(
    uintptr_t previous_or_tail) {
  UPB_ASSERT(_upb_Arena_IsTaggedPrevious(previous_or_tail));
  return (upb_ArenaInternal*)previous_or_tail;
}

static uintptr_t _upb_Arena_TaggedFromPrevious(upb_ArenaInternal* ai) {
  uintptr_t previous = (uintptr_t)ai;
  UPB_ASSERT(_upb_Arena_IsTaggedPrevious(previous));
  return previous;
}

static upb_alloc* _upb_ArenaInternal_BlockAlloc(upb_ArenaInternal* ai) {
  return (upb_alloc*)(ai->block_alloc & ~0x1);
}

static uintptr_t _upb_Arena_MakeBlockAlloc(upb_alloc* alloc, bool has_initial) {
  uintptr_t alloc_uint = (uintptr_t)alloc;
  UPB_ASSERT((alloc_uint & 1) == 0);
  return alloc_uint | (has_initial ? 1 : 0);
}

static bool _upb_ArenaInternal_HasInitialBlock(upb_ArenaInternal* ai) {
  return ai->block_alloc & 0x1;
}

#ifdef UPB_TRACING_ENABLED
static void (*_init_arena_trace_handler)(const upb_Arena*, size_t size) = NULL;
static void (*_fuse_arena_trace_handler)(const upb_Arena*,
                                         const upb_Arena*) = NULL;
static void (*_free_arena_trace_handler)(const upb_Arena*) = NULL;

void upb_Arena_SetTraceHandler(
    void (*initArenaTraceHandler)(const upb_Arena*, size_t size),
    void (*fuseArenaTraceHandler)(const upb_Arena*, const upb_Arena*),
    void (*freeArenaTraceHandler)(const upb_Arena*)) {
  _init_arena_trace_handler = initArenaTraceHandler;
  _fuse_arena_trace_handler = fuseArenaTraceHandler;
  _free_arena_trace_handler = freeArenaTraceHandler;
}

void upb_Arena_LogInit(const upb_Arena* arena, size_t size) {
  if (_init_arena_trace_handler) {
    _init_arena_trace_handler(arena, size);
  }
}
void upb_Arena_LogFuse(const upb_Arena* arena1, const upb_Arena* arena2) {
  if (_fuse_arena_trace_handler) {
    _fuse_arena_trace_handler(arena1, arena2);
  }
}
void upb_Arena_LogFree(const upb_Arena* arena) {
  if (_free_arena_trace_handler) {
    _free_arena_trace_handler(arena);
  }
}
#endif  // UPB_TRACING_ENABLED

// If the param a is already the root, provides no memory order of refcount.
// If it has a parent, then acquire memory order is provided for both the root
// and the refcount. Thread safe.
static upb_ArenaRoot _upb_Arena_FindRoot(upb_ArenaInternal* ai) {
  uintptr_t poc = upb_Atomic_Load(&ai->parent_or_count, memory_order_relaxed);
  if (_upb_Arena_IsTaggedRefcount(poc)) {
    // Fast, relaxed path - arenas that have never been fused to a parent only
    // need relaxed memory order, since they're returning themselves and the
    // refcount.
    return (upb_ArenaRoot){.root = ai, .tagged_count = poc};
  }
  // Slow path needs acquire order; reloading is cheaper than a fence on ARM
  // (LDA vs DMB ISH). Even though this is a reread, we know it must be a tagged
  // pointer because if this Arena isn't a root, it can't ever become one.
  poc = upb_Atomic_Load(&ai->parent_or_count, memory_order_acquire);
  do {
    upb_ArenaInternal* next = _upb_Arena_PointerFromTagged(poc);
    UPB_PRIVATE(upb_Xsan_AccessReadOnly)(UPB_XSAN(next));
    UPB_ASSERT(ai != next);
    poc = upb_Atomic_Load(&next->parent_or_count, memory_order_acquire);

    if (_upb_Arena_IsTaggedPointer(poc)) {
      // To keep complexity down, we lazily collapse levels of the tree.  This
      // keeps it flat in the final case, but doesn't cost much incrementally.
      //
      // Path splitting keeps time complexity down, see:
      //   https://en.wikipedia.org/wiki/Disjoint-set_data_structure
      UPB_ASSERT(ai != _upb_Arena_PointerFromTagged(poc));
      upb_Atomic_Store(&ai->parent_or_count, poc, memory_order_release);
    }
    ai = next;
  } while (_upb_Arena_IsTaggedPointer(poc));
  return (upb_ArenaRoot){.root = ai, .tagged_count = poc};
}

uintptr_t upb_Arena_SpaceAllocated(const upb_Arena* arena,
                                   size_t* fused_count) {
  upb_ArenaInternal* ai = upb_Arena_Internal(arena);
  uintptr_t memsize = 0;
  size_t local_fused_count = 0;
  // Our root would get updated by any racing fuses before our target arena
  // became reachable from the root via the linked list; in order to preserve
  // monotonic output (any arena counted by a previous invocation is counted by
  // this one), we instead iterate forwards and backwards so that we only see
  // the results of completed fuses.
  uintptr_t previous_or_tail =
      upb_Atomic_Load(&ai->previous_or_tail, memory_order_acquire);
  while (_upb_Arena_IsTaggedPrevious(previous_or_tail)) {
    upb_ArenaInternal* previous =
        _upb_Arena_PreviousFromTagged(previous_or_tail);
    UPB_ASSERT(previous != ai);
    UPB_PRIVATE(upb_Xsan_AccessReadOnly)(UPB_XSAN(previous));
    // Unfortunate macro behavior; prior to C11 when using nonstandard atomics
    // this returns a void* and can't be used with += without an intermediate
    // conversion to an integer.
    // Relaxed is safe - no subsequent reads depend this one
    uintptr_t allocated =
        upb_Atomic_Load(&previous->space_allocated, memory_order_relaxed);
    memsize += allocated;
    previous_or_tail =
        upb_Atomic_Load(&previous->previous_or_tail, memory_order_acquire);
    local_fused_count++;
  }
  while (ai != NULL) {
    UPB_PRIVATE(upb_Xsan_AccessReadOnly)(UPB_XSAN(ai));
    // Unfortunate macro behavior; prior to C11 when using nonstandard atomics
    // this returns a void* and can't be used with += without an intermediate
    // conversion to an integer.
    // Relaxed is safe - no subsequent reads depend this one
    uintptr_t allocated =
        upb_Atomic_Load(&ai->space_allocated, memory_order_relaxed);
    memsize += allocated;
    ai = upb_Atomic_Load(&ai->next, memory_order_acquire);
    local_fused_count++;
  }

  if (fused_count) *fused_count = local_fused_count;
  return memsize;
}

uint32_t upb_Arena_DebugRefCount(const upb_Arena* a) {
  uintptr_t tagged = _upb_Arena_FindRoot(upb_Arena_Internal(a)).tagged_count;
  return (uint32_t)_upb_Arena_RefCountFromTagged(tagged);
}

#if UPB_ENABLE_REF_CYCLE_CHECKS

bool upb_Arena_HasRefChain(const upb_Arena* from, const upb_Arena* to) {
  upb_ArenaInternal* ai = upb_Arena_Internal(from);
  upb_ArenaInternal* current;

  if (upb_Arena_IsFused(from, to)) return true;

  // 1. Traverse backward to the start of a consistent segment.
  uintptr_t previous_or_tail =
      upb_Atomic_Load(&ai->previous_or_tail, memory_order_acquire);
  while (_upb_Arena_IsTaggedPrevious(previous_or_tail)) {
    ai = _upb_Arena_PreviousFromTagged(previous_or_tail);
    UPB_PRIVATE(upb_Xsan_AccessReadOnly)(UPB_XSAN(ai));
    previous_or_tail =
        upb_Atomic_Load(&ai->previous_or_tail, memory_order_acquire);
  }

  // 2. Traverse forward through all arenas in the fuse group.
  current = ai;
  while (current != NULL) {
    UPB_PRIVATE(upb_Xsan_AccessReadOnly)(UPB_XSAN(current));
    const upb_ArenaRef* ref =
        upb_Atomic_Load(&current->refs, memory_order_acquire);
    while (ref != NULL) {
      if (ref->arena == to || upb_Arena_HasRefChain(ref->arena, to)) {
        return true;
      }
      ref = ref->next_ref;
    }
    current = upb_Atomic_Load(&current->next, memory_order_acquire);
  }
  return false;
}

#endif

static upb_MemBlock* _upb_Arena_AllocBlockInternal(upb_alloc* alloc,
                                                   size_t size) {
  UPB_ASSERT(size >= kUpb_MemblockReserve);
  upb_SizedPtr alloc_result = upb_SizeReturningMalloc(alloc, size);
  if (!alloc_result.p) return NULL;
  upb_MemBlock* block = alloc_result.p;
  block->size = alloc_result.n;
  return block;
}

static upb_MemBlock* _upb_Arena_AllocBlock(upb_Arena* a, size_t size) {
  upb_ArenaInternal* ai = upb_Arena_Internal(a);
  return _upb_Arena_AllocBlockInternal(_upb_ArenaInternal_BlockAlloc(ai), size);
}

static void _upb_Arena_AddBlock(upb_Arena* a, upb_MemBlock* block) {
  upb_ArenaInternal* ai = upb_Arena_Internal(a);

  // Atomic add not required here, as threads won't race allocating blocks, plus
  // atomic fetch-add is slower than load/add/store on arm devices compiled
  // targeting pre-v8.1. Relaxed order is safe as nothing depends on order of
  // size allocated.
  uintptr_t old_space_allocated =
      upb_Atomic_Load(&ai->space_allocated, memory_order_relaxed);
  upb_Atomic_Store(&ai->space_allocated, old_space_allocated + block->size,
                   memory_order_relaxed);

  block->next = ai->blocks;
  ai->blocks = block;
}

static void _upb_Arena_UseBlockInternal(upb_Arena* a, upb_MemBlock* block,
                                        size_t offset) {
  size_t block_size = block->size;
  char* start = UPB_PTR_AT(block, kUpb_MemblockReserve + offset, char);
  a->UPB_PRIVATE(ptr) = start;
  a->UPB_PRIVATE(end) = UPB_PTR_AT(block, block_size, char);
  UPB_PRIVATE(upb_Xsan_PoisonRegion)(start, a->UPB_PRIVATE(end) - start);
  UPB_PRIVATE(upb_Xsan_Init)(UPB_XSAN(a));
  UPB_ASSERT(UPB_PRIVATE(_upb_ArenaHas)(a) >=
             block_size - kUpb_MemblockReserve - offset);
}

static void _upb_Arena_UseBlock(upb_Arena* a, upb_MemBlock* block) {
  _upb_Arena_UseBlockInternal(a, block, 0);
}

static bool _upb_Arena_WouldReduceFreeSpace(upb_Arena* a, size_t size,
                                            size_t block_size) {
  upb_ArenaInternal* ai = upb_Arena_Internal(a);
  size_t current_free =
      ai->blocks ? a->UPB_PRIVATE(end) - a->UPB_PRIVATE(ptr) : 0;
  size_t future_free = block_size - kUpb_MemblockReserve - size;
  return current_free >= future_free;
}

// Fulfills the allocation request by allocating a new block. Returns NULL on
// allocation failure.
void* UPB_PRIVATE(_upb_Arena_SlowMalloc)(upb_Arena* a, size_t size) {
  upb_ArenaInternal* ai = upb_Arena_Internal(a);
  if (!ai->block_alloc) return NULL;

  // Whether to satisfy the allocation from a one-off block which is right-sized
  // for the current allocation. We do this if we suspect that the current
  // allocation is an outlier that does not represent the typical size of
  // allocations from this arena, or if we would reduce free space by
  // using exponential growth.
  bool one_off = false;

  // Relaxed order is safe here as we don't need any ordering with the setter.
  size_t max_block_size =
      upb_Atomic_Load(&g_max_block_size, memory_order_relaxed);
  size_t block_size = UPB_MIN(ai->last_block_size * 2, max_block_size);

  if (size + kUpb_MemblockReserve > block_size) {
    // A regular doubling would not yield a large enough block. Does size_hint
    // indicate that we have consistently needed large blocks?
    block_size = UPB_MIN(ai->size_hint * 2, max_block_size);
    if (size + kUpb_MemblockReserve > block_size) {
      // Even size_hint is not large enough, we will have to do a one-off.
      one_off = true;
    }
  }

  // If switching to a block of this size would *reduce* available free space,
  // we might as well make a one-off block instead.
  one_off = one_off || _upb_Arena_WouldReduceFreeSpace(a, size, block_size);

  if (one_off) {
    // Note: this may exceed the max block size, but that's okay.
    block_size = size + kUpb_MemblockReserve;
  }

  upb_MemBlock* block = _upb_Arena_AllocBlock(a, block_size);
  if (!block) return NULL;

  _upb_Arena_AddBlock(a, block);

  // Recheck size, in case the allocator gave us a much larger block than we
  // requested and we want to make it the new allocating region.
  if (UPB_UNLIKELY(one_off) &&
      _upb_Arena_WouldReduceFreeSpace(a, size, block->size)) {
    // Increase size_hint, so that a series of one-off allocations will
    // eventually convince us to switch to exponential growth at the larger
    // size.
    ai->size_hint = UPB_MIN(ai->size_hint + (size >> 1), max_block_size >> 1);
    char* allocated = UPB_PTR_AT(block, kUpb_MemblockReserve, char);
    char* poison_start = allocated + size - UPB_PRIVATE(kUpb_Asan_GuardSize);
    UPB_PRIVATE(upb_Xsan_PoisonRegion)(
        poison_start, UPB_PTR_AT(block, block->size, char) - poison_start);
    return allocated;
  } else {
    ai->last_block_size = UPB_MIN(block->size, UINT32_MAX);
    ai->size_hint = ai->last_block_size;
    _upb_Arena_UseBlock(a, block);
    UPB_ASSERT(UPB_PRIVATE(_upb_ArenaHas)(a) >= size);
    return upb_Arena_Malloc(a, size - UPB_PRIVATE(kUpb_Asan_GuardSize));
  }
}

static upb_Arena* _upb_Arena_InitSlow(upb_alloc* alloc, size_t first_size) {
  const size_t first_block_overhead =
      UPB_ALIGN_MALLOC(kUpb_MemblockReserve + sizeof(upb_ArenaState));
  upb_ArenaState* a;

  if (!alloc) return NULL;

  // We need to malloc the initial block.
  size_t block_size =
      first_block_overhead + UPB_MAX(256, UPB_ALIGN_MALLOC(first_size) +
                                              UPB_PRIVATE(kUpb_Asan_GuardSize));
  upb_MemBlock* block = _upb_Arena_AllocBlockInternal(alloc, block_size);
  if (!block) return NULL;

  // Initialize the arena state in the first block. We "borrow" the memory from
  // the block, because we can't yet call upb_Arena_Malloc.
  a = UPB_PTR_AT(block, kUpb_MemblockReserve, upb_ArenaState);
  a->body.block_alloc = _upb_Arena_MakeBlockAlloc(alloc, 0);
  a->body.last_block_size = UPB_MIN(block->size, UINT32_MAX);
  a->body.size_hint = UPB_MIN(block->size, UINT32_MAX);
  upb_Atomic_Init(&a->body.parent_or_count, _upb_Arena_TaggedFromRefcount(1));
  upb_Atomic_Init(&a->body.next, NULL);
  upb_Atomic_Init(&a->body.previous_or_tail,
                  _upb_Arena_TaggedFromTail(&a->body));
  upb_Atomic_Init(&a->body.space_allocated, 0);
  a->body.blocks = NULL;
#ifndef NDEBUG
  a->body.refs = NULL;
#endif
  a->body.upb_alloc_cleanup = NULL;
  UPB_PRIVATE(upb_Xsan_Init)(UPB_XSAN(&a->body));

  _upb_Arena_AddBlock(&a->head, block);
  _upb_Arena_UseBlockInternal(&a->head, block,
                              UPB_ALIGN_MALLOC(sizeof(upb_ArenaState)));

  return &a->head;
}

upb_Arena* upb_Arena_Init(void* mem, size_t n, upb_alloc* alloc) {
  UPB_STATIC_ASSERT(UPB_ARENA_SIZE_HACK >= sizeof(upb_ArenaState),
                    "Need to update UPB_ARENA_SIZE_HACK");
  upb_ArenaState* a;

  if (mem) {
    /* Align initial pointer up so that we return properly-aligned pointers. */
    void* aligned = (void*)UPB_ALIGN_MALLOC((uintptr_t)mem);
    size_t delta = (uintptr_t)aligned - (uintptr_t)mem;
    n = delta <= n ? n - delta : 0;
    mem = aligned;
  }
  if (UPB_UNLIKELY(n < sizeof(upb_ArenaState) || !mem)) {
    upb_Arena* ret = _upb_Arena_InitSlow(alloc, mem ? 0 : n);
#ifdef UPB_TRACING_ENABLED
    upb_Arena_LogInit(ret, n);
#endif
    return ret;
  }

  a = mem;

  upb_Atomic_Init(&a->body.parent_or_count, _upb_Arena_TaggedFromRefcount(1));
  upb_Atomic_Init(&a->body.next, NULL);
  upb_Atomic_Init(&a->body.previous_or_tail,
                  _upb_Arena_TaggedFromTail(&a->body));
  upb_Atomic_Init(&a->body.space_allocated, 0);
  a->body.blocks = NULL;
#ifndef NDEBUG
  a->body.refs = NULL;
#endif
  a->body.size_hint = 128;
  a->body.last_block_size = 128;
  a->body.upb_alloc_cleanup = NULL;
  a->body.block_alloc = _upb_Arena_MakeBlockAlloc(alloc, 1);
  a->head.UPB_PRIVATE(ptr) = (void*)UPB_ALIGN_MALLOC((uintptr_t)(a + 1));
  a->head.UPB_PRIVATE(end) = UPB_PTR_AT(mem, n, char);
  UPB_PRIVATE(upb_Xsan_Init)(UPB_XSAN(&a->body));
#ifdef UPB_TRACING_ENABLED
  upb_Arena_LogInit(&a->head, n);
#endif
  return &a->head;
}

static void _upb_Arena_DoFree(upb_ArenaInternal* ai) {
  UPB_ASSERT(_upb_Arena_RefCountFromTagged(ai->parent_or_count) == 1);
  while (ai != NULL) {
    UPB_PRIVATE(upb_Xsan_AccessReadWrite)(UPB_XSAN(ai));
    // Load first since arena itself is likely from one of its blocks. Relaxed
    // order is safe because fused arena ordering is provided by the reference
    // count, and fuse is not permitted to race with the final decrement.
    upb_ArenaInternal* next_arena =
        (upb_ArenaInternal*)upb_Atomic_Load(&ai->next, memory_order_relaxed);
    // Freeing may have memory barriers that confuse tsan, so assert immediately
    // after load here
    if (next_arena) {
      UPB_PRIVATE(upb_Xsan_AccessReadWrite)(UPB_XSAN(next_arena));
    }
    upb_alloc* block_alloc = _upb_ArenaInternal_BlockAlloc(ai);
    upb_MemBlock* block = ai->blocks;
    upb_AllocCleanupFunc* alloc_cleanup = *ai->upb_alloc_cleanup;
    while (block != NULL) {
      // Load first since we are deleting block.
      upb_MemBlock* next_block = block->next;
      if (block->size == 0) {
        // If the block is an arena ref, then we need to release our ref on the
        // referenced arena.
        upb_ArenaRef* ref = (upb_ArenaRef*)block;
        upb_Arena_DecRefFor((upb_Arena*)ref->arena, ai);
      } else {
        upb_free_sized(block_alloc, block, block->size);
      }
      block = next_block;
    }
    if (alloc_cleanup != NULL) {
      alloc_cleanup(block_alloc);
    }
    ai = next_arena;
  }
}

void upb_Arena_Free(upb_Arena* a) {
  upb_ArenaInternal* ai = upb_Arena_Internal(a);
  // Cannot be replaced with _upb_Arena_FindRoot, as that provides only a
  // relaxed read of the refcount if ai is already the root.
  uintptr_t poc = upb_Atomic_Load(&ai->parent_or_count, memory_order_acquire);
retry:
  while (_upb_Arena_IsTaggedPointer(poc)) {
    ai = _upb_Arena_PointerFromTagged(poc);
    UPB_PRIVATE(upb_Xsan_AccessReadOnly)(UPB_XSAN(ai));
    poc = upb_Atomic_Load(&ai->parent_or_count, memory_order_acquire);
  }

  // compare_exchange or fetch_sub are RMW operations, which are more
  // expensive then direct loads.  As an optimization, we only do RMW ops
  // when we need to update things for other threads to see.
  if (poc == _upb_Arena_TaggedFromRefcount(1)) {
#ifdef UPB_TRACING_ENABLED
    upb_Arena_LogFree(a);
#endif
    _upb_Arena_DoFree(ai);
    return;
  }

  if (upb_Atomic_CompareExchangeWeak(
          &ai->parent_or_count, &poc,
          _upb_Arena_TaggedFromRefcount(_upb_Arena_RefCountFromTagged(poc) - 1),
          memory_order_release, memory_order_acquire)) {
    // We were >1 and we decremented it successfully, so we are done.
    return;
  }

  // We failed our update, so someone has done something, retry the whole
  // process, but the failed exchange reloaded `poc` for us.
  goto retry;
}

// Logically performs the following operation, in a way that is safe against
// racing fuses:
//   ret = TAIL(parent)
//   ret->next = child
//   return ret
//
// The caller is therefore guaranteed that ret->next == child.
static upb_ArenaInternal* _upb_Arena_LinkForward(
    upb_ArenaInternal* const parent, upb_ArenaInternal* child) {
  UPB_PRIVATE(upb_Xsan_AccessReadOnly)(UPB_XSAN(parent));
  uintptr_t parent_previous_or_tail =
      upb_Atomic_Load(&parent->previous_or_tail, memory_order_acquire);

  // Optimization: use parent->previous_or_tail to skip to TAIL(parent) in O(1)
  // time when possible. This is the common case because we just fused into
  // parent, suggesting that it should be a root with a cached tail.
  //
  // However, if there was a racing fuse, parent may no longer be a root, in
  // which case we need to walk the entire list to find the tail. The tail
  // pointer is also not guaranteed to be the true tail, so even when the
  // optimization is taken, we still need to walk list nodes to find the true
  // tail.
  upb_ArenaInternal* parent_tail =
      _upb_Arena_IsTaggedTail(parent_previous_or_tail)
          ? _upb_Arena_TailFromTagged(parent_previous_or_tail)
          : parent;

  UPB_PRIVATE(upb_Xsan_AccessReadOnly)(UPB_XSAN(parent_tail));
  upb_ArenaInternal* parent_tail_next =
      upb_Atomic_Load(&parent_tail->next, memory_order_acquire);

  do {
    // Walk the list to find the true tail (a node with next == NULL).
    while (parent_tail_next != NULL) {
      parent_tail = parent_tail_next;
      UPB_PRIVATE(upb_Xsan_AccessReadOnly)(UPB_XSAN(parent_tail));
      parent_tail_next =
          upb_Atomic_Load(&parent_tail->next, memory_order_acquire);
    }
  } while (!upb_Atomic_CompareExchangeWeak(  // Replace a NULL next with child.
      &parent_tail->next, &parent_tail_next, child, memory_order_release,
      memory_order_acquire));

  return parent_tail;
}

// Updates parent->previous_or_tail = child->previous_or_tail in hopes that the
// latter represents the true tail of the newly-combined list.
//
// This is a best-effort operation that may set the tail to a stale value, and
// may fail to update the tail at all.
void _upb_Arena_UpdateParentTail(upb_ArenaInternal* parent,
                                 upb_ArenaInternal* child) {
  // We are guaranteed that child->previous_or_tail is tagged, because we have
  // just transitioned child from root -> non-root, which is an exclusive
  // operation that can only happen once. So we are the exclusive updater of
  // child->previous_or_tail that can transition it from tagged to untagged.
  //
  // However, we are not guaranteed that child->previous_or_tail is the true
  // tail.  A racing fuse may have appended to child's list but not yet updated
  // child->previous_or_tail.
  uintptr_t child_previous_or_tail =
      upb_Atomic_Load(&child->previous_or_tail, memory_order_acquire);
  upb_ArenaInternal* new_parent_tail =
      _upb_Arena_TailFromTagged(child_previous_or_tail);
  UPB_PRIVATE(upb_Xsan_AccessReadOnly)(UPB_XSAN(new_parent_tail));

  // If another thread fused with parent, such that it is no longer a root,
  // don't overwrite their previous pointer with our tail. Relaxed order is fine
  // here as we only inspect the tag bit.
  uintptr_t parent_previous_or_tail =
      upb_Atomic_Load(&parent->previous_or_tail, memory_order_relaxed);
  if (_upb_Arena_IsTaggedTail(parent_previous_or_tail)) {
    upb_Atomic_CompareExchangeStrong(
        &parent->previous_or_tail, &parent_previous_or_tail,
        _upb_Arena_TaggedFromTail(new_parent_tail), memory_order_release,
        memory_order_relaxed);
  }
}

static void _upb_Arena_LinkBackward(upb_ArenaInternal* child,
                                    upb_ArenaInternal* old_parent_tail) {
  // Link child to parent going backwards, for SpaceAllocated.  This transitions
  // child->previous_or_tail from tail (tagged) to previous (untagged), after
  // which its value is immutable.
  //
  // - We are guaranteed that no other threads are also attempting to perform
  //   this transition (tail -> previous), because we just updated
  //   old_parent_tail->next from NULL to non-NULL, an exclusive operation that
  //   can only happen once.
  //
  // - _upb_Arena_UpdateParentTail() uses CAS to ensure that it
  //    does not perform the reverse transition (previous -> tail).
  //
  // - We are guaranteed that old_parent_tail is the correct "previous" pointer,
  //   even in the presence of racing fuses that are adding more nodes to the
  //   list, because _upb_Arena_LinkForward() guarantees that:
  //       old_parent_tail->next == child.
  upb_Atomic_Store(&child->previous_or_tail,
                   _upb_Arena_TaggedFromPrevious(old_parent_tail),
                   memory_order_release);
}

static void _upb_Arena_DoFuseArenaLists(upb_ArenaInternal* const parent,
                                        upb_ArenaInternal* child) {
  upb_ArenaInternal* old_parent_tail = _upb_Arena_LinkForward(parent, child);
  _upb_Arena_UpdateParentTail(parent, child);
  _upb_Arena_LinkBackward(child, old_parent_tail);
}

void upb_Arena_SetAllocCleanup(upb_Arena* a, upb_AllocCleanupFunc* func) {
  UPB_PRIVATE(upb_Xsan_AccessReadWrite)(UPB_XSAN(a));
  upb_ArenaInternal* ai = upb_Arena_Internal(a);
  UPB_ASSERT(ai->upb_alloc_cleanup == NULL);
  ai->upb_alloc_cleanup = func;
}

// Thread safe.
static upb_ArenaInternal* _upb_Arena_DoFuse(upb_ArenaInternal** ai1,
                                            upb_ArenaInternal** ai2,
                                            uintptr_t* ref_delta) {
  // `parent_or_count` has two distinct modes
  // -  parent pointer mode
  // -  refcount mode
  //
  // In parent pointer mode, it may change what pointer it refers to in the
  // tree, but it will always approach a root.  Any operation that walks the
  // tree to the root may collapse levels of the tree concurrently.
  upb_ArenaRoot r1 = _upb_Arena_FindRoot(*ai1);
  upb_ArenaRoot r2 = _upb_Arena_FindRoot(*ai2);

  if (r1.root == r2.root) return r1.root;  // Already fused.

  *ai1 = r1.root;
  *ai2 = r2.root;

  // Avoid cycles by always fusing into the root with the lower address.
  if ((uintptr_t)r1.root > (uintptr_t)r2.root) {
    upb_ArenaRoot tmp = r1;
    r1 = r2;
    r2 = tmp;
  }

  // The moment we install `r1` as the parent for `r2` all racing frees may
  // immediately begin decrementing `r1`'s refcount (including pending
  // increments to that refcount and their frees!).  We need to add `r2`'s refs
  // now, so that `r1` can withstand any unrefs that come from r2.
  //
  // Note that while it is possible for `r2`'s refcount to increase
  // asynchronously, we will not actually do the reparenting operation below
  // unless `r2`'s refcount is unchanged from when we read it.
  //
  // Note that we may have done this previously, either to this node or a
  // different node, during a previous and failed DoFuse() attempt. But we will
  // not lose track of these refs because we always add them to our overall
  // delta.
  uintptr_t r2_untagged_count = r2.tagged_count & ~1;
  uintptr_t with_r2_refs = r1.tagged_count + r2_untagged_count;
  if (!upb_Atomic_CompareExchangeStrong(
          &r1.root->parent_or_count, &r1.tagged_count, with_r2_refs,
          memory_order_release, memory_order_acquire)) {
    return NULL;
  }

  // Perform the actual fuse by removing the refs from `r2` and swapping in the
  // parent pointer.
  if (!upb_Atomic_CompareExchangeStrong(
          &r2.root->parent_or_count, &r2.tagged_count,
          _upb_Arena_TaggedFromPointer(r1.root), memory_order_release,
          memory_order_acquire)) {
    // We'll need to remove the excess refs we added to r1 previously.
    *ref_delta += r2_untagged_count;
    return NULL;
  }

  // Now that the fuse has been performed (and can no longer fail) we need to
  // append `r2` to `r1`'s linked list.
  _upb_Arena_DoFuseArenaLists(r1.root, r2.root);
  return r1.root;
}

// Thread safe.
static bool _upb_Arena_FixupRefs(upb_ArenaInternal* new_root,
                                 uintptr_t ref_delta) {
  if (ref_delta == 0) return true;  // No fixup required.
  // Relaxed order is safe here as if the value is a pointer, we don't deref it
  // or publish it anywhere else. The refcount does provide memory order
  // between allocations on arenas and the eventual free and thus normally
  // requires acquire/release; but in this case any edges provided by the refs
  // we are cleaning up were already provided by the fuse operation itself. It's
  // not valid for a decrement that could cause the overall fused arena to reach
  // a zero refcount to race with this function, as that could result in a
  // use-after-free anyway.
  uintptr_t poc =
      upb_Atomic_Load(&new_root->parent_or_count, memory_order_relaxed);
  if (_upb_Arena_IsTaggedPointer(poc)) return false;
  uintptr_t with_refs = poc - ref_delta;
  UPB_ASSERT(!_upb_Arena_IsTaggedPointer(with_refs));
  // Relaxed order on success is safe here, for the same reasons as the relaxed
  // read above. Relaxed order is safe on failure because the updated value is
  // stored in a local variable which goes immediately out of scope; the retry
  // loop will reread what it needs with proper memory order.
  return upb_Atomic_CompareExchangeStrong(&new_root->parent_or_count, &poc,
                                          with_refs, memory_order_relaxed,
                                          memory_order_relaxed);
}

bool upb_Arena_Fuse(const upb_Arena* a1, const upb_Arena* a2) {
  if (a1 == a2) return true;  // trivial fuse

#ifdef UPB_TRACING_ENABLED
  upb_Arena_LogFuse(a1, a2);
#endif

  upb_ArenaInternal* ai1 = upb_Arena_Internal(a1);
  upb_ArenaInternal* ai2 = upb_Arena_Internal(a2);

  // Do not fuse initial blocks since we cannot lifetime extend them.
  // Any other fuse scenario is allowed.
  if (_upb_ArenaInternal_HasInitialBlock(ai1) ||
      _upb_ArenaInternal_HasInitialBlock(ai2)) {
    return false;
  }

  // The number of refs we ultimately need to transfer to the new root.
  uintptr_t ref_delta = 0;
  while (true) {
    upb_ArenaInternal* new_root = _upb_Arena_DoFuse(&ai1, &ai2, &ref_delta);
    if (new_root != NULL && _upb_Arena_FixupRefs(new_root, ref_delta)) {
#if UPB_ENABLE_REF_CYCLE_CHECKS
      UPB_ASSERT(!upb_Arena_HasRefChain(a1, a2));
#endif
      return true;
    }
  }
}

bool upb_Arena_IsFused(const upb_Arena* a, const upb_Arena* b) {
  if (a == b) return true;  // trivial fuse
  upb_ArenaInternal* ra = _upb_Arena_FindRoot(upb_Arena_Internal(a)).root;
  upb_ArenaInternal* rb = upb_Arena_Internal(b);
  while (true) {
    rb = _upb_Arena_FindRoot(rb).root;
    if (ra == rb) return true;
    upb_ArenaInternal* tmp = _upb_Arena_FindRoot(ra).root;
    if (ra == tmp) return false;
    // a's root changed since we last checked.  Retry.
    ra = tmp;
  }
}

bool upb_Arena_IncRefFor(const upb_Arena* a, const void* owner) {
  upb_ArenaInternal* ai = upb_Arena_Internal(a);
  if (_upb_ArenaInternal_HasInitialBlock(ai)) return false;
  upb_ArenaRoot r;
  r.root = ai;

retry:
  r = _upb_Arena_FindRoot(r.root);
  if (upb_Atomic_CompareExchangeWeak(
          &r.root->parent_or_count, &r.tagged_count,
          _upb_Arena_TaggedFromRefcount(
              _upb_Arena_RefCountFromTagged(r.tagged_count) + 1),
          // Relaxed order is safe on success, incrementing the refcount
          // need not perform any synchronization with the eventual free of the
          // arena - that's provided by decrements.
          memory_order_relaxed,
          // Relaxed order is safe on failure as r.tagged_count is immediately
          // overwritten by retrying the find root operation.
          memory_order_relaxed)) {
    // We incremented it successfully, so we are done.
    return true;
  }
  // We failed update due to parent switching on the arena.
  goto retry;
}

void upb_Arena_DecRefFor(const upb_Arena* a, const void* owner) {
  upb_Arena_Free((upb_Arena*)a);
}

bool upb_Arena_RefArena(upb_Arena* from, const upb_Arena* to) {
  UPB_ASSERT(!upb_Arena_IsFused(from, to));
  if (_upb_ArenaInternal_HasInitialBlock(upb_Arena_Internal(to))) {
    // We can't increment a ref to `to`, so return early.
    return false;
  }

  upb_ArenaInternal* ai = upb_Arena_Internal(from);
  upb_ArenaRef* ref = upb_Arena_Malloc(from, kUpb_ArenaRefReserve);

  if (!ref) {
    return false;
  }

  // When 'from' is freed, a ref on 'to' will be released.
  // Intentionally ignore return value, since we already check up above if this
  // call will succeed.
  bool result = upb_Arena_IncRefFor(to, from);
  UPB_ASSERT(result);

  // When we add a reference from `from` to `to`, we need to keep track of the
  // ref in the `from` arena's linked list of refs. This allows us to
  // walk all refs for `from` when `from` is freed, and thus allows us to
  // decrement the refcount on `to` when `from` is freed.
  ref->prefix.next = ai->blocks;
  ref->prefix.size = 0;
  ref->arena = to;
  ai->blocks = (upb_MemBlock*)ref;

#ifndef NDEBUG
  // Add to the dedicated list of refs.
  // This function is not thread-safe from `from`, so a simple load/store is
  // sufficient.
  ref->next_ref = upb_Atomic_Load(&ai->refs, memory_order_relaxed);
  upb_Atomic_Store(&ai->refs, ref, memory_order_release);
#endif

#if UPB_ENABLE_REF_CYCLE_CHECKS
  UPB_ASSERT(!upb_Arena_HasRefChain(to, from));  // Forbid cycles.
#endif

  return true;
}

#ifndef NDEBUG
bool upb_Arena_HasRef(const upb_Arena* from, const upb_Arena* to) {
  const upb_ArenaInternal* ai = upb_Arena_Internal(from);
  const upb_ArenaRef* ref = upb_Atomic_Load(&ai->refs, memory_order_acquire);
  while (ref != NULL) {
    if (upb_Arena_IsFused(ref->arena, to)) {
      return true;
    }
    ref = ref->next_ref;
  }
  return false;
}
#endif

upb_alloc* upb_Arena_GetUpbAlloc(upb_Arena* a) {
  UPB_PRIVATE(upb_Xsan_AccessReadOnly)(UPB_XSAN(a));
  upb_ArenaInternal* ai = upb_Arena_Internal(a);
  return _upb_ArenaInternal_BlockAlloc(ai);
}

void UPB_PRIVATE(_upb_Arena_SwapIn)(upb_Arena* des, const upb_Arena* src) {
  memcpy(des, src, offsetof(upb_ArenaState, body.space_allocated));
  upb_ArenaInternal* desi = upb_Arena_Internal(des);
  upb_ArenaInternal* srci = upb_Arena_Internal(src);
  uintptr_t new_space_allocated =
      upb_Atomic_Load(&srci->space_allocated, memory_order_relaxed);
  upb_Atomic_Store(&desi->space_allocated, new_space_allocated,
                   memory_order_relaxed);
}

void UPB_PRIVATE(_upb_Arena_SwapOut)(upb_Arena* des, const upb_Arena* src) {
  UPB_PRIVATE(_upb_Arena_SwapIn)(des, src);
}

bool _upb_Arena_WasLastAlloc(struct upb_Arena* a, void* ptr, size_t oldsize) {
  upb_ArenaInternal* ai = upb_Arena_Internal(a);
  upb_MemBlock* block = ai->blocks;
  // Skip any arena refs.
  while (block != NULL && block->size == 0) {
    block = block->next;
  }
  if (block == NULL) return false;
  char* start = UPB_PTR_AT(block, kUpb_MemblockReserve, char);
  return UPB_PRIVATE(upb_Xsan_PtrEq)(ptr, start) &&
         UPB_PRIVATE(_upb_Arena_AllocSpan)(oldsize) ==
             block->size - kUpb_MemblockReserve;
}



// Must be last.

bool upb_Message_SetMapEntry(upb_Map* map, const upb_MiniTableField* f,
                             upb_Message* map_entry_message, upb_Arena* arena) {
  UPB_ASSERT(!upb_Message_IsFrozen(map_entry_message));
  const upb_MiniTable* map_entry_mini_table =
      upb_MiniTable_MapEntrySubMessage(f);
  UPB_ASSERT(map_entry_mini_table);
  const upb_MiniTableField* map_entry_key_field =
      upb_MiniTable_MapKey(map_entry_mini_table);
  const upb_MiniTableField* map_entry_value_field =
      upb_MiniTable_MapValue(map_entry_mini_table);
  // Map key/value cannot have explicit defaults,
  // hence assuming a zero default is valid.
  upb_MessageValue default_val = upb_MessageValue_Zero();
  upb_MessageValue map_entry_key =
      upb_Message_GetField(map_entry_message, map_entry_key_field, default_val);
  upb_MessageValue map_entry_value = upb_Message_GetField(
      map_entry_message, map_entry_value_field, default_val);
  return upb_Map_Set(map, map_entry_key, map_entry_value, arena);
}


#include <stdint.h>
#include <string.h>


// Must be last.

upb_Array* upb_Array_New(upb_Arena* a, upb_CType type) {
  const int lg2 = UPB_PRIVATE(_upb_CType_SizeLg2)(type);
  return UPB_PRIVATE(_upb_Array_New)(a, 4, lg2);
}

upb_MessageValue upb_Array_Get(const upb_Array* arr, size_t i) {
  UPB_ASSERT(i < upb_Array_Size(arr));
  upb_MessageValue ret;
  const char* data = upb_Array_DataPtr(arr);
  const int lg2 = UPB_PRIVATE(_upb_Array_ElemSizeLg2)(arr);
  memcpy(&ret, data + (i << lg2), 1 << lg2);
  return ret;
}

upb_Message* upb_Array_GetMutable(upb_Array* arr, size_t i) {
  UPB_ASSERT(i < upb_Array_Size(arr));
  size_t elem_size = sizeof(upb_Message*);
  UPB_ASSERT(elem_size == (1 << UPB_PRIVATE(_upb_Array_ElemSizeLg2)(arr)));
  char* data = upb_Array_MutableDataPtr(arr);
  upb_Message* ret;
  memcpy(&ret, data + (i * elem_size), elem_size);
  UPB_ASSERT(!upb_Message_IsFrozen(ret));
  return ret;
}

void upb_Array_Set(upb_Array* arr, size_t i, upb_MessageValue val) {
  UPB_ASSERT(!upb_Array_IsFrozen(arr));
  UPB_ASSERT(i < upb_Array_Size(arr));
  char* data = upb_Array_MutableDataPtr(arr);
  const int lg2 = UPB_PRIVATE(_upb_Array_ElemSizeLg2)(arr);
  memcpy(data + (i << lg2), &val, 1 << lg2);
}

bool upb_Array_Append(upb_Array* arr, upb_MessageValue val, upb_Arena* arena) {
  UPB_ASSERT(!upb_Array_IsFrozen(arr));
  UPB_ASSERT(arena);
  if (!UPB_PRIVATE(_upb_Array_ResizeUninitialized)(
          arr, arr->UPB_PRIVATE(size) + 1, arena)) {
    return false;
  }
  upb_Array_Set(arr, arr->UPB_PRIVATE(size) - 1, val);
  return true;
}

bool upb_Array_Copy(upb_Array* dst, const upb_Array* src, upb_Arena* arena) {
  UPB_ASSERT(dst);
  UPB_ASSERT(src);
  UPB_ASSERT(!upb_Array_IsFrozen(dst));
  if (dst == src) return true;
  size_t len = upb_Array_Size(src);
  if (!UPB_PRIVATE(_upb_Array_ResizeUninitialized)(dst, len, arena)) {
    return false;
  }
  if (len == 0) return true;
  const int lg2 = UPB_PRIVATE(_upb_Array_ElemSizeLg2)(dst);
  const int src_lg2 = UPB_PRIVATE(_upb_Array_ElemSizeLg2)(src);
  UPB_ASSERT(lg2 == src_lg2);
  char* dst_data = upb_Array_MutableDataPtr(dst);
  const char* src_data = upb_Array_DataPtr(src);
  memcpy(dst_data, src_data, len << lg2);
  return true;
}

bool upb_Array_AppendAll(upb_Array* dst, const upb_Array* src,
                         upb_Arena* arena) {
  UPB_ASSERT(!upb_Array_IsFrozen(dst));
  UPB_ASSERT(src);
  size_t src_len = upb_Array_Size(src);
  if (src_len == 0) return true;
  size_t dst_len = upb_Array_Size(dst);
  size_t len = dst_len + src_len;
  if (UPB_UNLIKELY(len < dst_len)) return false;
  if (!UPB_PRIVATE(_upb_Array_ResizeUninitialized)(dst, len, arena)) {
    return false;
  }
  const int lg2 = UPB_PRIVATE(_upb_Array_ElemSizeLg2)(dst);
  const int src_lg2 = UPB_PRIVATE(_upb_Array_ElemSizeLg2)(src);
  UPB_ASSERT(lg2 == src_lg2);
  char* dst_data = upb_Array_MutableDataPtr(dst);
  const char* src_data = upb_Array_DataPtr(src);
  memcpy(dst_data + (dst_len << lg2), src_data, src_len << lg2);
  return true;
}

void upb_Array_Move(upb_Array* arr, size_t dst_idx, size_t src_idx,
                    size_t count) {
  UPB_ASSERT(!upb_Array_IsFrozen(arr));
  const int lg2 = UPB_PRIVATE(_upb_Array_ElemSizeLg2)(arr);
  char* data = upb_Array_MutableDataPtr(arr);
  memmove(&data[dst_idx << lg2], &data[src_idx << lg2], count << lg2);
}

bool upb_Array_Insert(upb_Array* arr, size_t i, size_t count,
                      upb_Arena* arena) {
  UPB_ASSERT(!upb_Array_IsFrozen(arr));
  UPB_ASSERT(arena);
  UPB_ASSERT(i <= arr->UPB_PRIVATE(size));
  UPB_ASSERT(count + arr->UPB_PRIVATE(size) >= count);
  const size_t oldsize = arr->UPB_PRIVATE(size);
  if (!UPB_PRIVATE(_upb_Array_ResizeUninitialized)(
          arr, arr->UPB_PRIVATE(size) + count, arena)) {
    return false;
  }
  upb_Array_Move(arr, i + count, i, oldsize - i);
  return true;
}

/*
 *              i        end      arr->size
 * |------------|XXXXXXXX|--------|
 */
void upb_Array_Delete(upb_Array* arr, size_t i, size_t count) {
  UPB_ASSERT(!upb_Array_IsFrozen(arr));
  const size_t end = i + count;
  UPB_ASSERT(i <= end);
  UPB_ASSERT(end <= arr->UPB_PRIVATE(size));
  upb_Array_Move(arr, i, end, arr->UPB_PRIVATE(size) - end);
  arr->UPB_PRIVATE(size) -= count;
}

bool upb_Array_Resize(upb_Array* arr, size_t size, upb_Arena* arena) {
  UPB_ASSERT(!upb_Array_IsFrozen(arr));
  const size_t oldsize = arr->UPB_PRIVATE(size);
  if (UPB_UNLIKELY(
          !UPB_PRIVATE(_upb_Array_ResizeUninitialized)(arr, size, arena))) {
    return false;
  }
  const size_t newsize = arr->UPB_PRIVATE(size);
  if (newsize > oldsize) {
    const int lg2 = UPB_PRIVATE(_upb_Array_ElemSizeLg2)(arr);
    char* data = upb_Array_MutableDataPtr(arr);
    memset(data + (oldsize << lg2), 0, (newsize - oldsize) << lg2);
  }
  return true;
}

bool UPB_PRIVATE(_upb_Array_Realloc)(upb_Array* array, size_t min_capacity,
                                     upb_Arena* arena) {
  size_t new_capacity = UPB_MAX(array->UPB_PRIVATE(capacity), 4);
  const int lg2 = UPB_PRIVATE(_upb_Array_ElemSizeLg2)(array);
  size_t old_bytes = array->UPB_PRIVATE(capacity) << lg2;
  void* ptr = upb_Array_MutableDataPtr(array);

  // Log2 ceiling of size.
  while (new_capacity < min_capacity) {
    if (upb_ShlOverflow(&new_capacity, 1)) {
      new_capacity = SIZE_MAX;
      break;
    }
  }

  size_t new_bytes = new_capacity;
  if (upb_ShlOverflow(&new_bytes, lg2)) {
    return false;
  }
  ptr = upb_Arena_Realloc(arena, ptr, old_bytes, new_bytes);
  if (!ptr) return false;

  UPB_PRIVATE(_upb_Array_SetTaggedPtr)(array, ptr, lg2);
  array->UPB_PRIVATE(capacity) = new_capacity;
  return true;
}

void upb_Array_Freeze(upb_Array* arr, const upb_MiniTable* m) {
  if (upb_Array_IsFrozen(arr)) return;
  UPB_PRIVATE(_upb_Array_ShallowFreeze)(arr);

  if (m) {
    const size_t size = upb_Array_Size(arr);

    for (size_t i = 0; i < size; i++) {
      upb_MessageValue val = upb_Array_Get(arr, i);
      upb_Message_Freeze((upb_Message*)val.msg_val, m);
    }
  }
}


#include <stddef.h>
#include <stdint.h>


// Must be last.

bool upb_Message_NextExtensionReverse(const upb_Message* msg,
                                      const upb_MiniTableExtension** result,
                                      uintptr_t* iter) {
  upb_MessageValue val;
  return UPB_PRIVATE(_upb_Message_NextExtensionReverse)(msg, result, &val,
                                                        iter);
}

const upb_MiniTableExtension* upb_Message_FindExtensionByNumber(
    const upb_Message* msg, uint32_t field_number) {
  uintptr_t iter = kUpb_Message_ExtensionBegin;
  const upb_MiniTableExtension* result;
  while (upb_Message_NextExtensionReverse(msg, &result, &iter)) {
    if (upb_MiniTableExtension_Number(result) == field_number) return result;
  }
  return NULL;
}


#include <stdint.h>
#include <string.h>


// Must be last.

// Strings/bytes are special-cased in maps.
char _upb_Map_CTypeSizeTable[12] = {
    [kUpb_CType_Bool] = 1,
    [kUpb_CType_Float] = 4,
    [kUpb_CType_Int32] = 4,
    [kUpb_CType_UInt32] = 4,
    [kUpb_CType_Enum] = 4,
    [kUpb_CType_Message] = sizeof(void*),
    [kUpb_CType_Double] = 8,
    [kUpb_CType_Int64] = 8,
    [kUpb_CType_UInt64] = 8,
    [kUpb_CType_String] = UPB_MAPTYPE_STRING,
    [kUpb_CType_Bytes] = UPB_MAPTYPE_STRING,
};

upb_Map* upb_Map_New(upb_Arena* a, upb_CType key_type, upb_CType value_type) {
  return _upb_Map_New(a, _upb_Map_CTypeSize(key_type),
                      _upb_Map_CTypeSize(value_type));
}

size_t upb_Map_Size(const upb_Map* map) { return _upb_Map_Size(map); }

bool upb_Map_Get(const upb_Map* map, upb_MessageValue key,
                 upb_MessageValue* val) {
  return _upb_Map_Get(map, &key, map->key_size, val, map->val_size);
}

struct upb_Message* upb_Map_GetMutable(upb_Map* map, upb_MessageValue key) {
  UPB_ASSERT(map->val_size == sizeof(upb_Message*));
  upb_Message* val = NULL;
  if (_upb_Map_Get(map, &key, map->key_size, &val, sizeof(upb_Message*))) {
    return val;
  } else {
    return NULL;
  }
}

void upb_Map_Clear(upb_Map* map) { _upb_Map_Clear(map); }

upb_MapInsertStatus upb_Map_Insert(upb_Map* map, upb_MessageValue key,
                                   upb_MessageValue val, upb_Arena* arena) {
  UPB_ASSERT(arena);
  return (upb_MapInsertStatus)_upb_Map_Insert(map, &key, map->key_size, &val,
                                              map->val_size, arena);
}

bool upb_Map_Delete(upb_Map* map, upb_MessageValue key, upb_MessageValue* val) {
  upb_value v;
  const bool removed = _upb_Map_Delete(map, &key, map->key_size, &v);
  if (val) _upb_map_fromvalue(v, val, map->val_size);
  return removed;
}

bool upb_Map_Next(const upb_Map* map, upb_MessageValue* key,
                  upb_MessageValue* val, size_t* iter) {
  upb_value v;
  bool ret;
  if (map->UPB_PRIVATE(is_strtable)) {
    upb_StringView strkey;
    ret = upb_strtable_next2(&map->t.strtable, &strkey, &v, (intptr_t*)iter);
    if (ret) {
      _upb_map_fromkey(strkey, key, map->key_size);
    }
  } else {
    uintptr_t intkey;
    ret = upb_inttable_next(&map->t.inttable, &intkey, &v, (intptr_t*)iter);
    if (ret) {
      memcpy(key, &intkey, map->key_size);
    }
  }
  if (ret) {
    _upb_map_fromvalue(v, val, map->val_size);
  }
  return ret;
}

UPB_API void upb_Map_SetEntryValue(upb_Map* map, size_t iter,
                                   upb_MessageValue val) {
  upb_value v;
  _upb_map_tovalue(&val, map->val_size, &v, NULL);
  if (map->UPB_PRIVATE(is_strtable)) {
    upb_strtable_setentryvalue(&map->t.strtable, iter, v);
  } else {
    upb_inttable_setentryvalue(&map->t.inttable, iter, v);
  }
}

bool upb_MapIterator_Next(const upb_Map* map, size_t* iter) {
  return _upb_map_next(map, iter);
}

bool upb_MapIterator_Done(const upb_Map* map, size_t iter) {
  UPB_ASSERT(iter != kUpb_Map_Begin);
  if (map->UPB_PRIVATE(is_strtable)) {
    upb_strtable_iter i;
    i.t = &map->t.strtable;
    i.index = iter;
    return upb_strtable_done(&i);
  } else {
    return upb_inttable_done(&map->t.inttable, iter);
  }
}

// Returns the key and value for this entry of the map.
upb_MessageValue upb_MapIterator_Key(const upb_Map* map, size_t iter) {
  upb_MessageValue ret;
  if (map->UPB_PRIVATE(is_strtable)) {
    upb_strtable_iter i;
    i.t = &map->t.strtable;
    i.index = iter;
    _upb_map_fromkey(upb_strtable_iter_key(&i), &ret, map->key_size);
  } else {
    uintptr_t intkey = upb_inttable_iter_key(&map->t.inttable, iter);
    memcpy(&ret, &intkey, map->key_size);
  }
  return ret;
}

upb_MessageValue upb_MapIterator_Value(const upb_Map* map, size_t iter) {
  upb_value v;
  if (map->UPB_PRIVATE(is_strtable)) {
    upb_strtable_iter i;
    i.t = &map->t.strtable;
    i.index = iter;
    v = upb_strtable_iter_value(&i);
  } else {
    v = upb_inttable_iter_value(&map->t.inttable, iter);
  }

  upb_MessageValue ret;
  _upb_map_fromvalue(v, &ret, map->val_size);
  return ret;
}

void upb_Map_Freeze(upb_Map* map, const upb_MiniTable* m) {
  if (upb_Map_IsFrozen(map)) return;
  UPB_PRIVATE(_upb_Map_ShallowFreeze)(map);

  if (m) {
    size_t iter = kUpb_Map_Begin;
    upb_MessageValue key, val;

    while (upb_Map_Next(map, &key, &val, &iter)) {
      upb_Message_Freeze((upb_Message*)val.msg_val, m);
    }
  }
}

// EVERYTHING BELOW THIS LINE IS INTERNAL - DO NOT USE /////////////////////////

upb_Map* _upb_Map_New(upb_Arena* a, size_t key_size, size_t value_size) {
  upb_Map* map = upb_Arena_Malloc(a, sizeof(upb_Map));
  if (!map) return NULL;

  if (key_size <= sizeof(uintptr_t) && key_size != UPB_MAPTYPE_STRING) {
    if (!upb_inttable_init(&map->t.inttable, a)) return NULL;
    map->UPB_PRIVATE(is_strtable) = false;
  } else {
    if (!upb_strtable_init(&map->t.strtable, 4, a)) return NULL;
    map->UPB_PRIVATE(is_strtable) = true;
  }
  map->key_size = key_size;
  map->val_size = value_size;
  map->UPB_PRIVATE(is_frozen) = false;

  return map;
}


#include <stdint.h>
#include <stdlib.h>
#include <string.h>


// Must be last.

static int _upb_mapsorter_intkeys(const void* _a, const void* _b) {
  const upb_tabent* const* a = _a;
  const upb_tabent* const* b = _b;
  uintptr_t a_key = (*a)->key.num;
  uintptr_t b_key = (*b)->key.num;
  return a_key < b_key ? -1 : a_key > b_key;
}

static void _upb_mapsorter_getkeys(const void* _a, const void* _b, void* a_key,
                                   void* b_key, size_t size) {
  const upb_tabent* const* a = _a;
  const upb_tabent* const* b = _b;
  upb_StringView a_tabkey = upb_key_strview((*a)->key);
  upb_StringView b_tabkey = upb_key_strview((*b)->key);
  _upb_map_fromkey(a_tabkey, a_key, size);
  _upb_map_fromkey(b_tabkey, b_key, size);
}

static int _upb_mapsorter_cmpi64(const void* _a, const void* _b) {
  int64_t a, b;
  _upb_mapsorter_getkeys(_a, _b, &a, &b, 8);
  return a < b ? -1 : a > b;
}

static int _upb_mapsorter_cmpu64(const void* _a, const void* _b) {
  uint64_t a, b;
  _upb_mapsorter_getkeys(_a, _b, &a, &b, 8);
  return a < b ? -1 : a > b;
}

static int _upb_mapsorter_cmpi32(const void* _a, const void* _b) {
  int32_t a, b;
  _upb_mapsorter_getkeys(_a, _b, &a, &b, 4);
  return a < b ? -1 : a > b;
}

static int _upb_mapsorter_cmpu32(const void* _a, const void* _b) {
  uint32_t a, b;
  _upb_mapsorter_getkeys(_a, _b, &a, &b, 4);
  return a < b ? -1 : a > b;
}

static int _upb_mapsorter_cmpbool(const void* _a, const void* _b) {
  bool a, b;
  _upb_mapsorter_getkeys(_a, _b, &a, &b, 1);
  return a < b ? -1 : a > b;
}

static int _upb_mapsorter_cmpstr(const void* _a, const void* _b) {
  upb_StringView a, b;
  _upb_mapsorter_getkeys(_a, _b, &a, &b, UPB_MAPTYPE_STRING);
  size_t common_size = UPB_MIN(a.size, b.size);
  int cmp = memcmp(a.data, b.data, common_size);
  if (cmp) return -cmp;
  return a.size < b.size ? -1 : a.size > b.size;
}

static int (*const compar[kUpb_FieldType_SizeOf])(const void*, const void*) = {
    [kUpb_FieldType_Int64] = _upb_mapsorter_cmpi64,
    [kUpb_FieldType_SFixed64] = _upb_mapsorter_cmpi64,
    [kUpb_FieldType_SInt64] = _upb_mapsorter_cmpi64,

    [kUpb_FieldType_UInt64] = _upb_mapsorter_cmpu64,
    [kUpb_FieldType_Fixed64] = _upb_mapsorter_cmpu64,

    [kUpb_FieldType_Int32] = _upb_mapsorter_cmpi32,
    [kUpb_FieldType_SInt32] = _upb_mapsorter_cmpi32,
    [kUpb_FieldType_SFixed32] = _upb_mapsorter_cmpi32,
    [kUpb_FieldType_Enum] = _upb_mapsorter_cmpi32,

    [kUpb_FieldType_UInt32] = _upb_mapsorter_cmpu32,
    [kUpb_FieldType_Fixed32] = _upb_mapsorter_cmpu32,

    [kUpb_FieldType_Bool] = _upb_mapsorter_cmpbool,

    [kUpb_FieldType_String] = _upb_mapsorter_cmpstr,
    [kUpb_FieldType_Bytes] = _upb_mapsorter_cmpstr,
};

static bool _upb_mapsorter_resize(_upb_mapsorter* s, _upb_sortedmap* sorted,
                                  int size) {
  sorted->start = s->size;
  sorted->pos = sorted->start;
  sorted->end = sorted->start + size;

  if (sorted->end > s->cap) {
    const int oldsize = s->cap * sizeof(*s->entries);
    s->cap = upb_RoundUpToPowerOfTwo(sorted->end);
    const int newsize = s->cap * sizeof(*s->entries);
    s->entries = upb_grealloc(s->entries, oldsize, newsize);
    if (!s->entries) return false;
  }

  s->size = sorted->end;
  return true;
}

bool _upb_mapsorter_pushmap(_upb_mapsorter* s, upb_FieldType key_type,
                            const upb_Map* map, _upb_sortedmap* sorted) {
  int map_size;
  if (map->UPB_PRIVATE(is_strtable)) {
    map_size = _upb_Map_Size(map);
  } else {
    // For inttable, only sort the table entries, since the array part is
    // already in a sorted order.
    map_size = map->t.inttable.t.count;
  }

  if (!_upb_mapsorter_resize(s, sorted, map_size)) return false;

  // Copy non-empty entries from the table to s->entries.
  const void** dst = &s->entries[sorted->start];
  const upb_tabent* src;
  const upb_tabent* end;
  if (map->UPB_PRIVATE(is_strtable)) {
    src = map->t.strtable.t.entries;
    end = src + upb_table_size(&map->t.strtable.t);
  } else {
    // For inttable, only sort the table entries, since the array part is
    // already in a sorted order.
    src = map->t.inttable.t.entries;
    end = src + upb_table_size(&map->t.inttable.t);
  }
  for (; src < end; src++) {
    if (!upb_tabent_isempty(src)) {
      *dst = src;
      dst++;
    }
  }
  UPB_ASSERT(dst == &s->entries[sorted->end]);

  // Sort entries according to the key type.
  qsort(&s->entries[sorted->start], map_size, sizeof(*s->entries),
        map->UPB_PRIVATE(is_strtable) ? compar[key_type]
                                      : _upb_mapsorter_intkeys);
  return true;
}

static int _upb_mapsorter_cmpext(const void* _a, const void* _b) {
  const upb_Extension* const* a = _a;
  const upb_Extension* const* b = _b;
  uint32_t a_num = upb_MiniTableExtension_Number((*a)->ext);
  uint32_t b_num = upb_MiniTableExtension_Number((*b)->ext);
  UPB_ASSERT(a_num != b_num);
  return a_num < b_num ? -1 : 1;
}

bool _upb_mapsorter_pushexts(_upb_mapsorter* s, const upb_Message_Internal* in,
                             _upb_sortedmap* sorted) {
  size_t count = 0;
  for (size_t i = 0; i < in->size; i++) {
    count += upb_TaggedAuxPtr_IsExtension(in->aux_data[i]);
  }
  if (!_upb_mapsorter_resize(s, sorted, count)) return false;
  if (count == 0) return true;
  const upb_Extension** entry =
      (const upb_Extension**)&s->entries[sorted->start];
  for (size_t i = 0; i < in->size; i++) {
    upb_TaggedAuxPtr tagged_ptr = in->aux_data[i];
    if (upb_TaggedAuxPtr_IsExtension(tagged_ptr)) {
      *entry++ = upb_TaggedAuxPtr_Extension(tagged_ptr);
    }
  }
  qsort(&s->entries[sorted->start], count, sizeof(*s->entries),
        _upb_mapsorter_cmpext);
  return true;
}


#include <stdarg.h>
#include <stddef.h>
#include <stdint.h>
#include <string.h>


// Must be last.

upb_Message* upb_Message_New(const upb_MiniTable* m, upb_Arena* a) {
  return _upb_Message_New(m, a);
}

UPB_NOINLINE bool UPB_PRIVATE(_upb_Message_AddUnknownSlowPath)(upb_Message* msg,
                                                               const char* data,
                                                               size_t len,
                                                               upb_Arena* arena,
                                                               bool alias) {
  {
    upb_Message_Internal* in = UPB_PRIVATE(_upb_Message_GetInternal)(msg);
    // Alias fast path was already checked in the inline function that calls
    // this one
    if (!alias && in && in->size) {
      upb_TaggedAuxPtr ptr = in->aux_data[in->size - 1];
      if (upb_TaggedAuxPtr_IsUnknown(ptr)) {
        upb_StringView* existing = upb_TaggedAuxPtr_UnknownData(ptr);
        if (!upb_TaggedAuxPtr_IsUnknownAliased(ptr)) {
          // If part of the existing field was deleted at the beginning, we can
          // reconstruct it by comparing the address of the end with the address
          // of the entry itself; having the non-aliased tag means that the
          // string_view and the data it points to are part of the same original
          // upb_Arena_Malloc allocation, and the end of the string view
          // represents the end of that allocation.
          size_t prev_alloc_size =
              (existing->data + existing->size) - (char*)existing;
          if (SIZE_MAX - prev_alloc_size >= len) {
            size_t new_alloc_size = prev_alloc_size + len;
            if (upb_Arena_TryExtend(arena, existing, prev_alloc_size,
                                    new_alloc_size)) {
              memcpy(UPB_PTR_AT(existing, prev_alloc_size, void), data, len);
              existing->size += len;
              return true;
            }
          }
        }
      }
    }
  }
  // TODO: b/376969853  - Add debug check that the unknown field is an overall
  // valid proto field
  if (!UPB_PRIVATE(_upb_Message_ReserveSlot)(msg, arena)) {
    return false;
  }
  upb_StringView* view;
  if (alias) {
    view = upb_Arena_Malloc(arena, sizeof(upb_StringView));
    if (!view) return false;
    view->data = data;
  } else {
    if (SIZE_MAX - sizeof(upb_StringView) < len) return false;
    view = upb_Arena_Malloc(arena, sizeof(upb_StringView) + len);
    if (!view) return false;
    char* copy = UPB_PTR_AT(view, sizeof(upb_StringView), char);
    memcpy(copy, data, len);
    view->data = copy;
  }
  view->size = len;
  upb_Message_Internal* in = UPB_PRIVATE(_upb_Message_GetInternal)(msg);
  in->aux_data[in->size++] = alias
                                 ? upb_TaggedAuxPtr_MakeUnknownDataAliased(view)
                                 : upb_TaggedAuxPtr_MakeUnknownData(view);
  return true;
}

bool UPB_PRIVATE(_upb_Message_AddUnknownV)(struct upb_Message* msg,
                                           upb_Arena* arena,
                                           upb_StringView data[],
                                           size_t count) {
  UPB_ASSERT(!upb_Message_IsFrozen(msg));
  UPB_ASSERT(count > 0);
  size_t total_len = 0;
  for (size_t i = 0; i < count; i++) {
    if (SIZE_MAX - total_len < data[i].size) {
      return false;
    }
    total_len += data[i].size;
  }

  {
    upb_Message_Internal* in = UPB_PRIVATE(_upb_Message_GetInternal)(msg);
    if (in && in->size) {
      upb_TaggedAuxPtr ptr = in->aux_data[in->size - 1];
      if (upb_TaggedAuxPtr_IsUnknown(ptr)) {
        upb_StringView* existing = upb_TaggedAuxPtr_UnknownData(ptr);
        if (!upb_TaggedAuxPtr_IsUnknownAliased(ptr)) {
          size_t prev_alloc_size =
              (existing->data + existing->size) - (char*)existing;
          if (SIZE_MAX - prev_alloc_size >= total_len) {
            size_t new_alloc_size = prev_alloc_size + total_len;
            if (upb_Arena_TryExtend(arena, existing, prev_alloc_size,
                                    new_alloc_size)) {
              char* copy = UPB_PTR_AT(existing, prev_alloc_size, char);
              for (size_t i = 0; i < count; i++) {
                memcpy(copy, data[i].data, data[i].size);
                copy += data[i].size;
              }
              existing->size += total_len;
              return true;
            }
          }
        }
      }
    }
  }

  if (SIZE_MAX - sizeof(upb_StringView) < total_len) return false;
  if (!UPB_PRIVATE(_upb_Message_ReserveSlot)(msg, arena)) return false;

  upb_StringView* view =
      upb_Arena_Malloc(arena, sizeof(upb_StringView) + total_len);
  if (!view) return false;
  char* copy = UPB_PTR_AT(view, sizeof(upb_StringView), char);
  view->data = copy;
  view->size = total_len;
  for (size_t i = 0; i < count; i++) {
    memcpy(copy, data[i].data, data[i].size);
    copy += data[i].size;
  }
  // TODO: b/376969853  - Add debug check that the unknown field is an overall
  // valid proto field
  upb_Message_Internal* in = UPB_PRIVATE(_upb_Message_GetInternal)(msg);
  in->aux_data[in->size++] = upb_TaggedAuxPtr_MakeUnknownData(view);
  return true;
}

void _upb_Message_DiscardUnknown_shallow(upb_Message* msg) {
  UPB_ASSERT(!upb_Message_IsFrozen(msg));
  upb_Message_Internal* in = UPB_PRIVATE(_upb_Message_GetInternal)(msg);
  if (!in) return;
  uint32_t size = 0;
  for (uint32_t i = 0; i < in->size; i++) {
    upb_TaggedAuxPtr tagged_ptr = in->aux_data[i];
    if (upb_TaggedAuxPtr_IsExtension(tagged_ptr)) {
      in->aux_data[size++] = tagged_ptr;
    }
  }
  in->size = size;
}

upb_Message_DeleteUnknownStatus upb_Message_DeleteUnknown(upb_Message* msg,
                                                          upb_StringView* data,
                                                          uintptr_t* iter,
                                                          upb_Arena* arena) {
  UPB_ASSERT(!upb_Message_IsFrozen(msg));
  UPB_ASSERT(*iter != kUpb_Message_UnknownBegin);
  upb_Message_Internal* in = UPB_PRIVATE(_upb_Message_GetInternal)(msg);
  UPB_ASSERT(in);
  UPB_ASSERT(*iter <= in->size);
  upb_TaggedAuxPtr unknown_ptr = in->aux_data[*iter - 1];
  UPB_ASSERT(upb_TaggedAuxPtr_IsUnknown(unknown_ptr));
  upb_StringView* unknown = upb_TaggedAuxPtr_UnknownData(unknown_ptr);
  if (unknown->data == data->data && unknown->size == data->size) {
    // Remove whole field
    in->aux_data[*iter - 1] = upb_TaggedAuxPtr_Null();
  } else if (unknown->data == data->data) {
    // Strip prefix
    unknown->data += data->size;
    unknown->size -= data->size;
    *data = *unknown;
    return kUpb_DeleteUnknown_IterUpdated;
  } else if (unknown->data + unknown->size == data->data + data->size) {
    // Truncate existing field
    unknown->size -= data->size;
    if (!upb_TaggedAuxPtr_IsUnknownAliased(unknown_ptr)) {
      in->aux_data[*iter - 1] =
          upb_TaggedAuxPtr_MakeUnknownDataAliased(unknown);
    }
  } else {
    UPB_ASSERT(unknown->data < data->data &&
               unknown->data + unknown->size > data->data + data->size);
    // Split in the middle
    upb_StringView* prefix = unknown;
    upb_StringView* suffix = upb_Arena_Malloc(arena, sizeof(upb_StringView));
    if (!suffix) {
      return kUpb_DeleteUnknown_AllocFail;
    }
    if (!UPB_PRIVATE(_upb_Message_ReserveSlot)(msg, arena)) {
      return kUpb_DeleteUnknown_AllocFail;
    }
    in = UPB_PRIVATE(_upb_Message_GetInternal)(msg);
    if (*iter != in->size) {
      // Shift later entries down so that unknown field ordering is preserved
      memmove(&in->aux_data[*iter + 1], &in->aux_data[*iter],
              sizeof(upb_TaggedAuxPtr) * (in->size - *iter));
    }
    in->aux_data[*iter] = upb_TaggedAuxPtr_MakeUnknownDataAliased(suffix);
    if (!upb_TaggedAuxPtr_IsUnknownAliased(unknown_ptr)) {
      in->aux_data[*iter - 1] = upb_TaggedAuxPtr_MakeUnknownDataAliased(prefix);
    }
    in->size++;
    suffix->data = data->data + data->size;
    suffix->size = (prefix->data + prefix->size) - suffix->data;
    prefix->size = data->data - prefix->data;
  }
  return upb_Message_NextUnknown(msg, data, iter)
             ? kUpb_DeleteUnknown_IterUpdated
             : kUpb_DeleteUnknown_DeletedLast;
}

size_t upb_Message_ExtensionCount(const upb_Message* msg) {
  upb_Message_Internal* in = UPB_PRIVATE(_upb_Message_GetInternal)(msg);
  if (!in) return 0;
  const upb_MiniTableExtension* ext;
  upb_MessageValue val;
  uintptr_t iter = kUpb_Message_ExtensionBegin;
  size_t count = 0;
  while (upb_Message_NextExtension(msg, &ext, &val, &iter)) {
    count++;
  }
  return count;
}

void upb_Message_Freeze(upb_Message* msg, const upb_MiniTable* m) {
  if (upb_Message_IsFrozen(msg)) return;
  UPB_PRIVATE(_upb_Message_ShallowFreeze)(msg);

  // Base Fields.
  const size_t field_count = upb_MiniTable_FieldCount(m);

  for (size_t i = 0; i < field_count; i++) {
    const upb_MiniTableField* f = upb_MiniTable_GetFieldByIndex(m, i);
    const upb_MiniTable* m2 = upb_MiniTable_SubMessage(f);

    switch (UPB_PRIVATE(_upb_MiniTableField_Mode)(f)) {
      case kUpb_FieldMode_Array: {
        upb_Array* arr = upb_Message_GetMutableArray(msg, f);
        if (arr) upb_Array_Freeze(arr, m2);
        break;
      }
      case kUpb_FieldMode_Map: {
        upb_Map* map = upb_Message_GetMutableMap(msg, f);
        if (map) {
          const upb_MiniTableField* f2 = upb_MiniTable_MapValue(m2);
          const upb_MiniTable* m3 = upb_MiniTable_SubMessage(f2);
          upb_Map_Freeze(map, m3);
        }
        break;
      }
      case kUpb_FieldMode_Scalar: {
        if (m2) {
          upb_Message* msg2 = upb_Message_GetMutableMessage(msg, f);
          if (msg2) upb_Message_Freeze(msg2, m2);
        }
        break;
      }
    }
  }

  // Extensions.
  upb_Message_Internal* in = UPB_PRIVATE(_upb_Message_GetInternal)(msg);
  // TODO: b/376969853 - use iterator API
  uint32_t size = in ? in->size : 0;
  for (size_t i = 0; i < size; i++) {
    upb_TaggedAuxPtr tagged_ptr = in->aux_data[i];
    if (!upb_TaggedAuxPtr_IsExtension(tagged_ptr)) {
      continue;
    }
    const upb_Extension* ext = upb_TaggedAuxPtr_Extension(tagged_ptr);
    const upb_MiniTableExtension* e = ext->ext;
    const upb_MiniTableField* f = &e->UPB_PRIVATE(field);
    const upb_MiniTable* m2 = upb_MiniTableExtension_GetSubMessage(e);

    upb_MessageValue val;
    memcpy(&val, &(ext->data), sizeof(upb_MessageValue));

    switch (UPB_PRIVATE(_upb_MiniTableField_Mode)(f)) {
      case kUpb_FieldMode_Array: {
        upb_Array* arr = (upb_Array*)val.array_val;
        if (arr) upb_Array_Freeze(arr, m2);
        break;
      }
      case kUpb_FieldMode_Map:
        UPB_UNREACHABLE();  // Maps cannot be extensions.
        break;
      case kUpb_FieldMode_Scalar:
        if (upb_MiniTableField_IsSubMessage(f)) {
          upb_Message* msg2 = (upb_Message*)val.msg_val;
          if (msg2) upb_Message_Freeze(msg2, m2);
        }
        break;
    }
  }
}


#include <stddef.h>
#include <stdint.h>


// Must be last.


#ifdef __cplusplus
extern "C" {
#endif

bool upb_Message_IsEmpty(const upb_Message* msg, const upb_MiniTable* m) {
  if (upb_Message_ExtensionCount(msg)) return false;

  const upb_MiniTableField* f;
  upb_MessageValue v;
  size_t iter = kUpb_BaseField_Begin;
  return !UPB_PRIVATE(_upb_Message_NextBaseField)(msg, m, &f, &v, &iter);
}

static bool _upb_Array_IsEqual(const upb_Array* arr1, const upb_Array* arr2,
                               upb_CType ctype, const upb_MiniTable* m,
                               int options) {
  // Check for trivial equality.
  if (arr1 == arr2) return true;

  // Must have identical element counts.
  const size_t size1 = arr1 ? upb_Array_Size(arr1) : 0;
  const size_t size2 = arr2 ? upb_Array_Size(arr2) : 0;
  if (size1 != size2) return false;

  for (size_t i = 0; i < size1; i++) {
    const upb_MessageValue val1 = upb_Array_Get(arr1, i);
    const upb_MessageValue val2 = upb_Array_Get(arr2, i);

    if (!upb_MessageValue_IsEqual(val1, val2, ctype, m, options)) return false;
  }

  return true;
}

static bool _upb_Map_IsEqual(const upb_Map* map1, const upb_Map* map2,
                             const upb_MiniTable* m, int options) {
  // Check for trivial equality.
  if (map1 == map2) return true;

  // Must have identical element counts.
  size_t size1 = map1 ? upb_Map_Size(map1) : 0;
  size_t size2 = map2 ? upb_Map_Size(map2) : 0;
  if (size1 != size2) return false;

  const upb_MiniTableField* f = upb_MiniTable_MapValue(m);
  const upb_MiniTable* m2_value = upb_MiniTable_SubMessage(f);
  const upb_CType ctype = upb_MiniTableField_CType(f);

  upb_MessageValue key, val1, val2;
  size_t iter = kUpb_Map_Begin;
  while (upb_Map_Next(map1, &key, &val1, &iter)) {
    if (!upb_Map_Get(map2, key, &val2)) return false;
    if (!upb_MessageValue_IsEqual(val1, val2, ctype, m2_value, options))
      return false;
  }

  return true;
}

static bool _upb_Message_BaseFieldsAreEqual(const upb_Message* msg1,
                                            const upb_Message* msg2,
                                            const upb_MiniTable* m,
                                            int options) {
  // Iterate over all base fields for each message.
  // The order will always match if the messages are equal.
  size_t iter1 = kUpb_BaseField_Begin;
  size_t iter2 = kUpb_BaseField_Begin;

  for (;;) {
    const upb_MiniTableField *f1, *f2;
    upb_MessageValue val1, val2;

    const bool got1 =
        UPB_PRIVATE(_upb_Message_NextBaseField)(msg1, m, &f1, &val1, &iter1);
    const bool got2 =
        UPB_PRIVATE(_upb_Message_NextBaseField)(msg2, m, &f2, &val2, &iter2);

    if (got1 != got2) return false;  // Must have identical field counts.
    if (!got1) return true;          // Loop termination condition.
    if (f1 != f2) return false;      // Must have identical fields set.

    const upb_MiniTable* subm = upb_MiniTable_SubMessage(f1);
    const upb_CType ctype = upb_MiniTableField_CType(f1);

    bool eq;
    switch (UPB_PRIVATE(_upb_MiniTableField_Mode)(f1)) {
      case kUpb_FieldMode_Array:
        eq = _upb_Array_IsEqual(val1.array_val, val2.array_val, ctype, subm,
                                options);
        break;
      case kUpb_FieldMode_Map:
        eq = _upb_Map_IsEqual(val1.map_val, val2.map_val, subm, options);
        break;
      case kUpb_FieldMode_Scalar:
        eq = upb_MessageValue_IsEqual(val1, val2, ctype, subm, options);
        break;
    }
    if (!eq) return false;
  }
}

static bool _upb_Message_ExtensionsAreEqual(const upb_Message* msg1,
                                            const upb_Message* msg2,
                                            const upb_MiniTable* m,
                                            int options) {
  const upb_MiniTableExtension* e;
  upb_MessageValue val1;

  // Iterate over all extensions for msg1, and search msg2 for each extension.
  size_t count1 = 0;
  size_t iter1 = kUpb_Message_ExtensionBegin;
  while (upb_Message_NextExtension(msg1, &e, &val1, &iter1)) {
    const upb_Extension* ext2 = UPB_PRIVATE(_upb_Message_Getext)(msg2, e);
    if (!ext2) return false;

    count1++;

    const upb_MessageValue val2 = ext2->data;
    const upb_MiniTableField* f = &e->UPB_PRIVATE(field);
    const upb_MiniTable* subm = upb_MiniTableField_IsSubMessage(f)
                                    ? upb_MiniTableExtension_GetSubMessage(e)
                                    : NULL;
    const upb_CType ctype = upb_MiniTableField_CType(f);

    bool eq;
    switch (UPB_PRIVATE(_upb_MiniTableField_Mode)(f)) {
      case kUpb_FieldMode_Array:
        eq = _upb_Array_IsEqual(val1.array_val, val2.array_val, ctype, subm,
                                options);
        break;
      case kUpb_FieldMode_Map:
        UPB_UNREACHABLE();  // Maps cannot be extensions.
        break;
      case kUpb_FieldMode_Scalar: {
        eq = upb_MessageValue_IsEqual(val1, val2, ctype, subm, options);
        break;
      }
    }
    if (!eq) return false;
  }

  // Must have identical extension counts (this catches the case where msg2
  // has extensions that msg1 doesn't).
  if (count1 != upb_Message_ExtensionCount(msg2)) return false;

  return true;
}

bool upb_Message_IsEqual(const upb_Message* msg1, const upb_Message* msg2,
                         const upb_MiniTable* m, int options) {
  if (UPB_UNLIKELY(msg1 == msg2)) return true;

  if (!_upb_Message_BaseFieldsAreEqual(msg1, msg2, m, options)) return false;
  if (!_upb_Message_ExtensionsAreEqual(msg1, msg2, m, options)) return false;

  if (!(options & kUpb_CompareOption_IncludeUnknownFields)) return true;

  // The wire encoder enforces a maximum depth of 100 so we match that here.
  return UPB_PRIVATE(_upb_Message_UnknownFieldsAreEqual)(msg1, msg2, 100) ==
         kUpb_UnknownCompareResult_Equal;
}


#include <stdint.h>
#include <stdlib.h>


// Must be last.

typedef struct upb_UnknownFields upb_UnknownFields;

typedef struct {
  uint32_t tag;
  union {
    uint64_t varint;
    uint64_t uint64;
    uint32_t uint32;
    upb_StringView delimited;
    upb_UnknownFields* group;
  } data;
} upb_UnknownField;

struct upb_UnknownFields {
  size_t size;
  size_t capacity;
  upb_UnknownField* fields;
};

typedef struct {
  upb_EpsCopyInputStream stream;
  upb_Arena* arena;
  upb_UnknownField* tmp;
  size_t tmp_size;
  int depth;
  upb_UnknownCompareResult status;
  jmp_buf err;
} upb_UnknownField_Context;

typedef struct {
  upb_UnknownField* arr_base;
  upb_UnknownField* arr_ptr;
  upb_UnknownField* arr_end;
  uint32_t last_tag;
  bool sorted;
} upb_UnknownFields_Builder;

UPB_NORETURN static void upb_UnknownFields_OutOfMemory(
    upb_UnknownField_Context* ctx) {
  ctx->status = kUpb_UnknownCompareResult_OutOfMemory;
  UPB_LONGJMP(ctx->err, 1);
}

static void upb_UnknownFields_Grow(upb_UnknownField_Context* ctx,
                                   upb_UnknownField** base,
                                   upb_UnknownField** ptr,
                                   upb_UnknownField** end) {
  size_t old = (*ptr - *base);
  size_t new = UPB_MAX(4, old * 2);

  *base = upb_Arena_Realloc(ctx->arena, *base, old * sizeof(**base),
                            new * sizeof(**base));
  if (!*base) upb_UnknownFields_OutOfMemory(ctx);

  *ptr = *base + old;
  *end = *base + new;
}

// We have to implement our own sort here, since qsort() is not an in-order
// sort. Here we use merge sort, the simplest in-order sort.
static void upb_UnknownFields_Merge(upb_UnknownField* arr, size_t start,
                                    size_t mid, size_t end,
                                    upb_UnknownField* tmp) {
  memcpy(tmp, &arr[start], (end - start) * sizeof(*tmp));

  upb_UnknownField* ptr1 = tmp;
  upb_UnknownField* end1 = &tmp[mid - start];
  upb_UnknownField* ptr2 = &tmp[mid - start];
  upb_UnknownField* end2 = &tmp[end - start];
  upb_UnknownField* out = &arr[start];

  while (ptr1 < end1 && ptr2 < end2) {
    if (ptr1->tag <= ptr2->tag) {
      *out++ = *ptr1++;
    } else {
      *out++ = *ptr2++;
    }
  }

  if (ptr1 < end1) {
    memcpy(out, ptr1, (end1 - ptr1) * sizeof(*out));
  } else if (ptr2 < end2) {
    memcpy(out, ptr1, (end2 - ptr2) * sizeof(*out));
  }
}

static void upb_UnknownFields_SortRecursive(upb_UnknownField* arr, size_t start,
                                            size_t end, upb_UnknownField* tmp) {
  if (end - start > 1) {
    size_t mid = start + ((end - start) / 2);
    upb_UnknownFields_SortRecursive(arr, start, mid, tmp);
    upb_UnknownFields_SortRecursive(arr, mid, end, tmp);
    upb_UnknownFields_Merge(arr, start, mid, end, tmp);
  }
}

static void upb_UnknownFields_Sort(upb_UnknownField_Context* ctx,
                                   upb_UnknownFields* fields) {
  if (ctx->tmp_size < fields->size) {
    const int oldsize = ctx->tmp_size * sizeof(*ctx->tmp);
    ctx->tmp_size = UPB_MAX(8, ctx->tmp_size);
    while (ctx->tmp_size < fields->size) ctx->tmp_size *= 2;
    const int newsize = ctx->tmp_size * sizeof(*ctx->tmp);
    ctx->tmp = upb_grealloc(ctx->tmp, oldsize, newsize);
  }
  upb_UnknownFields_SortRecursive(fields->fields, 0, fields->size, ctx->tmp);
}

static upb_UnknownFields* upb_UnknownFields_BuildFromBuffer(
    upb_UnknownField_Context* ctx, const char** buf);

// Combines two unknown fields into one.
static void upb_CombineUnknownFields(upb_UnknownField_Context* ctx,
                                     upb_UnknownFields_Builder* builder,
                                     const char** buf) {
  upb_UnknownField* arr_base = builder->arr_base;
  upb_UnknownField* arr_ptr = builder->arr_ptr;
  upb_UnknownField* arr_end = builder->arr_end;
  const char* ptr = *buf;
  uint32_t last_tag = builder->last_tag;
  bool sorted = builder->sorted;

  // Parse the unknown field data. It is an invariant of the data structure that
  // unknown field data is valid, so parse errors here should be impossible.
  while (!upb_EpsCopyInputStream_IsDone(&ctx->stream, &ptr)) {
    uint32_t tag;
    ptr = upb_WireReader_ReadTag(ptr, &tag, &ctx->stream);
    UPB_ASSERT(tag <= UINT32_MAX);
    int wire_type = upb_WireReader_GetWireType(tag);
    if (wire_type == kUpb_WireType_EndGroup) break;
    if (tag < last_tag) sorted = false;
    last_tag = tag;

    if (arr_ptr == arr_end) {
      upb_UnknownFields_Grow(ctx, &arr_base, &arr_ptr, &arr_end);
    }
    upb_UnknownField* field = arr_ptr;
    field->tag = tag;
    arr_ptr++;

    switch (wire_type) {
      case kUpb_WireType_Varint:
        ptr = upb_WireReader_ReadVarint(ptr, &field->data.varint, &ctx->stream);
        UPB_ASSERT(ptr);
        break;
      case kUpb_WireType_64Bit:
        ptr =
            upb_WireReader_ReadFixed64(ptr, &field->data.uint64, &ctx->stream);
        UPB_ASSERT(ptr);
        break;
      case kUpb_WireType_32Bit:
        ptr =
            upb_WireReader_ReadFixed32(ptr, &field->data.uint32, &ctx->stream);
        UPB_ASSERT(ptr);
        break;
      case kUpb_WireType_Delimited: {
        int size;
        upb_StringView sv;
        ptr = upb_WireReader_ReadSize(ptr, &size, &ctx->stream);
        UPB_ASSERT(ptr);
        ptr = upb_EpsCopyInputStream_ReadStringAlwaysAlias(&ctx->stream, ptr,
                                                           size, &sv);
        UPB_ASSERT(ptr);
        field->data.delimited.data = sv.data;
        field->data.delimited.size = sv.size;
        break;
      }
      case kUpb_WireType_StartGroup:
        if (--ctx->depth < 0) {
          ctx->status = kUpb_UnknownCompareResult_MaxDepthExceeded;
          UPB_LONGJMP(ctx->err, 1);
        }
        field->data.group = upb_UnknownFields_BuildFromBuffer(ctx, &ptr);
        ctx->depth++;
        break;
      default:
        UPB_UNREACHABLE();
    }
  }
  *buf = ptr;
  builder->arr_base = arr_base;
  builder->arr_ptr = arr_ptr;
  builder->arr_end = arr_end;
  builder->sorted = sorted;
  builder->last_tag = last_tag;
}

static upb_UnknownFields* upb_UnknownFields_DoBuild(
    upb_UnknownField_Context* ctx, upb_UnknownFields_Builder* builder) {
  upb_UnknownFields* ret = upb_Arena_Malloc(ctx->arena, sizeof(*ret));
  if (!ret) upb_UnknownFields_OutOfMemory(ctx);
  ret->fields = builder->arr_base;
  ret->size = builder->arr_ptr - builder->arr_base;
  ret->capacity = builder->arr_end - builder->arr_base;
  if (!builder->sorted) {
    upb_UnknownFields_Sort(ctx, ret);
  }
  return ret;
}

// Builds a upb_UnknownFields data structure from the binary data in buf.
static upb_UnknownFields* upb_UnknownFields_BuildFromBuffer(
    upb_UnknownField_Context* ctx, const char** buf) {
  upb_UnknownFields_Builder builder = {
      .arr_base = NULL,
      .arr_ptr = NULL,
      .arr_end = NULL,
      .sorted = true,
      .last_tag = 0,
  };
  const char* ptr = *buf;
  upb_CombineUnknownFields(ctx, &builder, &ptr);
  upb_UnknownFields* fields = upb_UnknownFields_DoBuild(ctx, &builder);
  *buf = ptr;
  return fields;
}

// Builds a upb_UnknownFields data structure from the unknown fields of a
// upb_Message.
static upb_UnknownFields* upb_UnknownFields_Build(upb_UnknownField_Context* ctx,
                                                  const upb_Message* msg) {
  upb_UnknownFields_Builder builder = {
      .arr_base = NULL,
      .arr_ptr = NULL,
      .arr_end = NULL,
      .sorted = true,
      .last_tag = 0,
  };
  uintptr_t iter = kUpb_Message_UnknownBegin;
  upb_StringView view;
  while (upb_Message_NextUnknown(msg, &view, &iter)) {
    upb_EpsCopyInputStream_Init(&ctx->stream, &view.data, view.size);
    upb_CombineUnknownFields(ctx, &builder, &view.data);
    UPB_ASSERT(upb_EpsCopyInputStream_IsDone(&ctx->stream, &view.data) &&
               !upb_EpsCopyInputStream_IsError(&ctx->stream));
  }
  upb_UnknownFields* fields = upb_UnknownFields_DoBuild(ctx, &builder);
  return fields;
}

// Compares two sorted upb_UnknownFields structures for equality.
static bool upb_UnknownFields_IsEqual(const upb_UnknownFields* uf1,
                                      const upb_UnknownFields* uf2) {
  if (uf1->size != uf2->size) return false;
  for (size_t i = 0, n = uf1->size; i < n; i++) {
    upb_UnknownField* f1 = &uf1->fields[i];
    upb_UnknownField* f2 = &uf2->fields[i];
    if (f1->tag != f2->tag) return false;
    int wire_type = f1->tag & 7;
    switch (wire_type) {
      case kUpb_WireType_Varint:
        if (f1->data.varint != f2->data.varint) return false;
        break;
      case kUpb_WireType_64Bit:
        if (f1->data.uint64 != f2->data.uint64) return false;
        break;
      case kUpb_WireType_32Bit:
        if (f1->data.uint32 != f2->data.uint32) return false;
        break;
      case kUpb_WireType_Delimited:
        if (!upb_StringView_IsEqual(f1->data.delimited, f2->data.delimited)) {
          return false;
        }
        break;
      case kUpb_WireType_StartGroup:
        if (!upb_UnknownFields_IsEqual(f1->data.group, f2->data.group)) {
          return false;
        }
        break;
      default:
        UPB_UNREACHABLE();
    }
  }
  return true;
}

static upb_UnknownCompareResult upb_UnknownField_DoCompare(
    upb_UnknownField_Context* ctx, const upb_Message* msg1,
    const upb_Message* msg2) {
  upb_UnknownCompareResult ret;
  // First build both unknown fields into a sorted data structure (similar
  // to the UnknownFieldSet in C++).
  upb_UnknownFields* uf1 = upb_UnknownFields_Build(ctx, msg1);
  upb_UnknownFields* uf2 = upb_UnknownFields_Build(ctx, msg2);

  // Now perform the equality check on the sorted structures.
  if (upb_UnknownFields_IsEqual(uf1, uf2)) {
    ret = kUpb_UnknownCompareResult_Equal;
  } else {
    ret = kUpb_UnknownCompareResult_NotEqual;
  }
  return ret;
}

static upb_UnknownCompareResult upb_UnknownField_Compare(
    upb_UnknownField_Context* const ctx, const upb_Message* msg1,
    const upb_Message* msg2) {
  upb_UnknownCompareResult ret;
  if (UPB_SETJMP(ctx->err) == 0) {
    ret = upb_UnknownField_DoCompare(ctx, msg1, msg2);
  } else {
    ret = ctx->status;
    UPB_ASSERT(ret != kUpb_UnknownCompareResult_Equal);
  }

  upb_Arena_Free(ctx->arena);
  upb_gfree(ctx->tmp);
  return ret;
}

upb_UnknownCompareResult UPB_PRIVATE(_upb_Message_UnknownFieldsAreEqual)(
    const upb_Message* msg1, const upb_Message* msg2, int max_depth) {
  bool msg1_empty = !upb_Message_HasUnknown(msg1);
  bool msg2_empty = !upb_Message_HasUnknown(msg2);
  if (msg1_empty && msg2_empty) return kUpb_UnknownCompareResult_Equal;
  if (msg1_empty || msg2_empty) return kUpb_UnknownCompareResult_NotEqual;

  upb_UnknownField_Context ctx = {
      .arena = upb_Arena_New(),
      .depth = max_depth,
      .tmp = NULL,
      .tmp_size = 0,
      .status = kUpb_UnknownCompareResult_Equal,
  };

  if (!ctx.arena) return kUpb_UnknownCompareResult_OutOfMemory;

  return upb_UnknownField_Compare(&ctx, msg1, msg2);
}


#include <stdbool.h>
#include <stdint.h>
#include <string.h>


// Must be last.

static upb_StringView upb_Clone_StringView(upb_StringView str,
                                           upb_Arena* arena) {
  if (str.size == 0) {
    return upb_StringView_FromDataAndSize(NULL, 0);
  }
  void* cloned_data = upb_Arena_Malloc(arena, str.size);
  upb_StringView cloned_str =
      upb_StringView_FromDataAndSize(cloned_data, str.size);
  memcpy(cloned_data, str.data, str.size);
  return cloned_str;
}

static bool upb_Clone_MessageValue(void* value, upb_CType value_type,
                                   const upb_MiniTable* sub, upb_Arena* arena) {
  switch (value_type) {
    case kUpb_CType_Bool:
    case kUpb_CType_Float:
    case kUpb_CType_Int32:
    case kUpb_CType_UInt32:
    case kUpb_CType_Enum:
    case kUpb_CType_Double:
    case kUpb_CType_Int64:
    case kUpb_CType_UInt64:
      return true;
    case kUpb_CType_String:
    case kUpb_CType_Bytes: {
      upb_StringView source = *(upb_StringView*)value;
      size_t size = source.size;
      void* cloned_data = upb_Arena_Malloc(arena, size);
      if (cloned_data == NULL) {
        return false;
      }
      *(upb_StringView*)value =
          upb_StringView_FromDataAndSize(cloned_data, size);
      memcpy(cloned_data, source.data, size);
      return true;
    } break;
    case kUpb_CType_Message: {
      UPB_ASSERT(sub);
      const upb_Message* source = *(upb_Message**)value;
      UPB_ASSERT(source);
      upb_Message* clone = upb_Message_DeepClone(source, sub, arena);
      *(upb_Message**)value = clone;
      return clone != NULL;
    } break;
  }
  UPB_UNREACHABLE();
}

upb_Map* upb_Map_DeepClone(const upb_Map* map, upb_CType key_type,
                           upb_CType value_type,
                           const upb_MiniTable* map_entry_table,
                           upb_Arena* arena) {
  upb_Map* cloned_map = _upb_Map_New(arena, map->key_size, map->val_size);
  if (cloned_map == NULL) {
    return NULL;
  }
  upb_MessageValue key, val;
  size_t iter = kUpb_Map_Begin;
  while (upb_Map_Next(map, &key, &val, &iter)) {
    const upb_MiniTableField* value_field =
        upb_MiniTable_MapValue(map_entry_table);
    const upb_MiniTable* value_sub =
        upb_MiniTableField_CType(value_field) == kUpb_CType_Message
            ? upb_MiniTable_GetSubMessageTable(value_field)
            : NULL;
    upb_CType value_field_type = upb_MiniTableField_CType(value_field);
    if (!upb_Clone_MessageValue(&val, value_field_type, value_sub, arena)) {
      return NULL;
    }
    if (!upb_Map_Set(cloned_map, key, val, arena)) {
      return NULL;
    }
  }
  return cloned_map;
}

static upb_Map* upb_Message_Map_DeepClone(const upb_Map* map,
                                          const upb_MiniTable* mini_table,
                                          const upb_MiniTableField* f,
                                          upb_Message* clone,
                                          upb_Arena* arena) {
  UPB_ASSERT(!upb_Message_IsFrozen(clone));
  const upb_MiniTable* map_entry_table = upb_MiniTable_MapEntrySubMessage(f);
  UPB_ASSERT(map_entry_table);

  const upb_MiniTableField* key_field = upb_MiniTable_MapKey(map_entry_table);
  const upb_MiniTableField* value_field =
      upb_MiniTable_MapValue(map_entry_table);

  upb_Map* cloned_map = upb_Map_DeepClone(
      map, upb_MiniTableField_CType(key_field),
      upb_MiniTableField_CType(value_field), map_entry_table, arena);
  if (!cloned_map) {
    return NULL;
  }
  upb_Message_SetBaseField(clone, f, &cloned_map);
  return cloned_map;
}

upb_Array* upb_Array_DeepClone(const upb_Array* array, upb_CType value_type,
                               const upb_MiniTable* sub, upb_Arena* arena) {
  const size_t size = upb_Array_Size(array);
  const int lg2 = UPB_PRIVATE(_upb_CType_SizeLg2)(value_type);
  upb_Array* cloned_array = UPB_PRIVATE(_upb_Array_New)(arena, size, lg2);
  if (!cloned_array) {
    return NULL;
  }
  if (!UPB_PRIVATE(_upb_Array_ResizeUninitialized)(cloned_array, size, arena)) {
    return NULL;
  }
  for (size_t i = 0; i < size; ++i) {
    upb_MessageValue val = upb_Array_Get(array, i);
    if (!upb_Clone_MessageValue(&val, value_type, sub, arena)) {
      return NULL;
    }
    upb_Array_Set(cloned_array, i, val);
  }
  return cloned_array;
}

static bool upb_Message_Array_DeepClone(const upb_Array* array,
                                        const upb_MiniTable* mini_table,
                                        const upb_MiniTableField* field,
                                        upb_Message* clone, upb_Arena* arena) {
  UPB_ASSERT(!upb_Message_IsFrozen(clone));
  UPB_PRIVATE(_upb_MiniTableField_CheckIsArray)(field);
  upb_Array* cloned_array =
      upb_Array_DeepClone(array, upb_MiniTableField_CType(field),
                          upb_MiniTableField_CType(field) == kUpb_CType_Message
                              ? upb_MiniTable_GetSubMessageTable(field)
                              : NULL,
                          arena);

  // Clear out upb_Array* due to parent memcpy.
  upb_Message_SetBaseField(clone, field, &cloned_array);
  return true;
}

static bool upb_Clone_ExtensionValue(
    const upb_MiniTableExtension* mini_table_ext, const upb_Extension* source,
    upb_Extension* dest, upb_Arena* arena) {
  dest->data = source->data;
  return upb_Clone_MessageValue(
      &dest->data, upb_MiniTableExtension_CType(mini_table_ext),
      upb_MiniTableExtension_GetSubMessage(mini_table_ext), arena);
}

upb_Message* _upb_Message_Copy(upb_Message* dst, const upb_Message* src,
                               const upb_MiniTable* mini_table,
                               upb_Arena* arena) {
  UPB_ASSERT(!upb_Message_IsFrozen(dst));
  upb_StringView empty_string = upb_StringView_FromDataAndSize(NULL, 0);
  // Only copy message area skipping upb_Message_Internal.
  memcpy(dst + 1, src + 1, mini_table->UPB_PRIVATE(size) - sizeof(upb_Message));
  for (int i = 0; i < upb_MiniTable_FieldCount(mini_table); ++i) {
    const upb_MiniTableField* field =
        upb_MiniTable_GetFieldByIndex(mini_table, i);
    if (upb_MiniTableField_IsScalar(field)) {
      switch (upb_MiniTableField_CType(field)) {
        case kUpb_CType_Message: {
          const upb_Message* sub_message = upb_Message_GetMessage(src, field);
          if (sub_message != NULL) {
            const upb_MiniTable* sub_message_table =
                upb_MiniTable_GetSubMessageTable(field);
            upb_Message* dst_sub_message =
                upb_Message_DeepClone(sub_message, sub_message_table, arena);
            if (dst_sub_message == NULL) {
              return NULL;
            }
            upb_Message_SetBaseFieldMessage(dst, field, dst_sub_message);
          }
        } break;
        case kUpb_CType_String:
        case kUpb_CType_Bytes: {
          upb_StringView str = upb_Message_GetString(src, field, empty_string);
          if (str.size != 0) {
            if (!upb_Message_SetString(
                    dst, field, upb_Clone_StringView(str, arena), arena)) {
              return NULL;
            }
          }
        } break;
        default:
          // Scalar, already copied.
          break;
      }
    } else {
      if (upb_MiniTableField_IsMap(field)) {
        const upb_Map* map = upb_Message_GetMap(src, field);
        if (map != NULL) {
          if (!upb_Message_Map_DeepClone(map, mini_table, field, dst, arena)) {
            return NULL;
          }
        }
      } else {
        const upb_Array* array = upb_Message_GetArray(src, field);
        if (array != NULL) {
          if (!upb_Message_Array_DeepClone(array, mini_table, field, dst,
                                           arena)) {
            return NULL;
          }
        }
      }
    }
  }
  // Clone extensions.
  upb_Message_Internal* in = UPB_PRIVATE(_upb_Message_GetInternal)(src);
  if (!in) return dst;

  for (size_t i = 0; i < in->size; i++) {
    upb_TaggedAuxPtr tagged_ptr = in->aux_data[i];
    if (upb_TaggedAuxPtr_IsExtension(tagged_ptr)) {
      // Clone extension
      const upb_Extension* msg_ext = upb_TaggedAuxPtr_Extension(tagged_ptr);
      const upb_MiniTableField* field = &msg_ext->ext->UPB_PRIVATE(field);
      upb_Extension* dst_ext = UPB_PRIVATE(_upb_Message_GetOrCreateExtension)(
          dst, msg_ext->ext, arena);
      if (!dst_ext) return NULL;
      if (upb_MiniTableField_IsScalar(field)) {
        if (!upb_Clone_ExtensionValue(msg_ext->ext, msg_ext, dst_ext, arena)) {
          return NULL;
        }
      } else {
        upb_Array* msg_array = (upb_Array*)msg_ext->data.array_val;
        UPB_ASSERT(msg_array);
        upb_Array* cloned_array = upb_Array_DeepClone(
            msg_array, upb_MiniTableField_CType(field),
            upb_MiniTableExtension_GetSubMessage(msg_ext->ext), arena);
        if (!cloned_array) {
          return NULL;
        }
        dst_ext->data.array_val = cloned_array;
      }
    } else if (upb_TaggedAuxPtr_IsUnknown(tagged_ptr)) {
      // Clone unknown
      upb_StringView* unknown = upb_TaggedAuxPtr_UnknownData(tagged_ptr);
      // Make a copy into destination arena.
      if (!UPB_PRIVATE(_upb_Message_AddUnknown)(
              dst, unknown->data, unknown->size, arena, kUpb_AddUnknown_Copy)) {
        return NULL;
      }
    }
  }

  return dst;
}

bool upb_Message_DeepCopy(upb_Message* dst, const upb_Message* src,
                          const upb_MiniTable* mini_table, upb_Arena* arena) {
  UPB_ASSERT(!upb_Message_IsFrozen(dst));
  upb_Message_Clear(dst, mini_table);
  return _upb_Message_Copy(dst, src, mini_table, arena) != NULL;
}

// Deep clones a message using the provided target arena.
//
// Returns NULL on failure.
upb_Message* upb_Message_DeepClone(const upb_Message* msg,
                                   const upb_MiniTable* m, upb_Arena* arena) {
  upb_Message* clone = upb_Message_New(m, arena);
  return _upb_Message_Copy(clone, msg, m, arena);
}

// Performs a shallow copy. TODO: Extend to handle unknown fields.
void upb_Message_ShallowCopy(upb_Message* dst, const upb_Message* src,
                             const upb_MiniTable* m) {
  UPB_ASSERT(!upb_Message_IsFrozen(dst));
  memcpy(dst, src, m->UPB_PRIVATE(size));
}

// Performs a shallow clone. Ignores unknown fields.
upb_Message* upb_Message_ShallowClone(const upb_Message* msg,
                                      const upb_MiniTable* m,
                                      upb_Arena* arena) {
  upb_Message* clone = upb_Message_New(m, arena);
  upb_Message_ShallowCopy(clone, msg, m);
  return clone;
}

#include "stddef.h"

// Must be last.

bool upb_Message_MergeFrom(upb_Message* dst, const upb_Message* src,
                           const upb_MiniTable* mt,
                           const upb_ExtensionRegistry* extreg,
                           upb_Arena* arena) {
  char* buf = NULL;
  size_t size = 0;
  // This tmp arena is used to hold the bytes for `src` serialized. This bends
  // the typical "no hidden allocations" design of upb, but under a properly
  // optimized implementation this extra allocation would not be necessary and
  // so we don't want to unnecessarily have the bad API or bloat the passed-in
  // arena with this very-short-term allocation.
  upb_Arena* encode_arena = upb_Arena_New();
  upb_EncodeStatus e_status = upb_Encode(src, mt, 0, encode_arena, &buf, &size);
  if (e_status != kUpb_EncodeStatus_Ok) {
    upb_Arena_Free(encode_arena);
    return false;
  }
  upb_DecodeStatus d_status = upb_Decode(buf, size, dst, mt, extreg, 0, arena);
  if (d_status != kUpb_DecodeStatus_Ok) {
    upb_Arena_Free(encode_arena);
    return false;
  }
  upb_Arena_Free(encode_arena);
  return true;
}


#include <stdint.h>
#include <string.h>


// Must be last.

const upb_Extension* UPB_PRIVATE(_upb_Message_Getext)(
    const struct upb_Message* msg, const upb_MiniTableExtension* e) {
  upb_Message_Internal* in = UPB_PRIVATE(_upb_Message_GetInternal)(msg);
  if (!in) return NULL;

  for (size_t i = 0; i < in->size; i++) {
    upb_TaggedAuxPtr tagged_ptr = in->aux_data[i];
    if (upb_TaggedAuxPtr_IsExtension(tagged_ptr)) {
      const upb_Extension* ext = upb_TaggedAuxPtr_Extension(tagged_ptr);
      if (ext->ext == e) {
        return ext;
      }
    }
  }

  return NULL;
}

upb_Extension* UPB_PRIVATE(_upb_Message_GetOrCreateExtension)(
    struct upb_Message* msg, const upb_MiniTableExtension* e, upb_Arena* a) {
  UPB_ASSERT(!upb_Message_IsFrozen(msg));
  upb_Extension* ext = (upb_Extension*)UPB_PRIVATE(_upb_Message_Getext)(msg, e);
  if (ext) return ext;

  if (!UPB_PRIVATE(_upb_Message_ReserveSlot)(msg, a)) return NULL;
  upb_Message_Internal* in = UPB_PRIVATE(_upb_Message_GetInternal)(msg);
  ext = upb_Arena_Malloc(a, sizeof(upb_Extension));
  if (!ext) return NULL;
  memset(ext, 0, sizeof(upb_Extension));
  ext->ext = e;
  in->aux_data[in->size++] = upb_TaggedAuxPtr_MakeExtension(ext);
  return ext;
}


#include <math.h>
#include <stddef.h>
#include <stdint.h>
#include <string.h>


// Must be last.

// The latest win32 SDKs have an invalid definition of NAN.
// https://developercommunity.visualstudio.com/t/NAN-is-no-longer-compile-time-constant-i/10688907
//
// Unfortunately, the `0.0 / 0.0` workaround doesn't work in Clang under C23, so
// try __builtin_nan first, if that exists.
#ifdef _WIN32
#ifdef __has_builtin
#if __has_builtin(__builtin_nan)
#define UPB_NAN __builtin_nan("0")
#endif
#if __has_builtin(__builtin_inf)
#define UPB_INFINITY __builtin_inf()
#endif
#endif
#ifndef UPB_NAN
#define UPB_NAN 0.0 / 0.0
#endif
#ifndef UPB_INFINITY
#define UPB_INFINITY 1.0 / 0.0
#endif
#else
// For !_WIN32, assume math.h works.
#define UPB_NAN NAN
#define UPB_INFINITY INFINITY
#endif

const float kUpb_FltInfinity = UPB_INFINITY;
const double kUpb_Infinity = UPB_INFINITY;
const double kUpb_NaN = UPB_NAN;

static size_t _upb_Message_SizeOfInternal(uint32_t count) {
  return UPB_SIZEOF_FLEX(upb_Message_Internal, aux_data, count);
}

bool UPB_PRIVATE(_upb_Message_ReserveSlot)(struct upb_Message* msg,
                                           upb_Arena* a) {
  UPB_ASSERT(!upb_Message_IsFrozen(msg));
  upb_Message_Internal* in = UPB_PRIVATE(_upb_Message_GetInternal)(msg);
  if (!in) {
    // No internal data, allocate from scratch.
    uint32_t capacity = 4;
    in = upb_Arena_Malloc(a, _upb_Message_SizeOfInternal(capacity));
    if (!in) return false;
    in->size = 0;
    in->capacity = capacity;
    UPB_PRIVATE(_upb_Message_SetInternal)(msg, in);
  } else if (in->capacity == in->size) {
    if (in->size == UINT32_MAX) return false;
    // Internal data is too small, reallocate.
    size_t needed_pow2 = upb_RoundUpToPowerOfTwo(in->size + 1);
    if (needed_pow2 > UINT32_MAX) return false;
    uint32_t new_capacity = needed_pow2;
    if (UPB_SIZEOF_FLEX_WOULD_OVERFLOW(upb_Message_Internal, aux_data,
                                       new_capacity)) {
      return false;
    }
    in = upb_Arena_Realloc(a, in, _upb_Message_SizeOfInternal(in->capacity),
                           _upb_Message_SizeOfInternal(new_capacity));
    if (!in) return false;
    in->capacity = new_capacity;
    UPB_PRIVATE(_upb_Message_SetInternal)(msg, in);
  }
  UPB_ASSERT(in->capacity - in->size >= 1);
  return true;
}

#ifdef UPB_TRACING_ENABLED
static void (*_message_trace_handler)(const upb_MiniTable*, const upb_Arena*);

void upb_Message_LogNewMessage(const upb_MiniTable* m, const upb_Arena* arena) {
  if (_message_trace_handler) {
    _message_trace_handler(m, arena);
  }
}

void upb_Message_SetNewMessageTraceHandler(void (*handler)(const upb_MiniTable*,
                                                           const upb_Arena*)) {
  _message_trace_handler = handler;
}
#endif  // UPB_TRACING_ENABLED


#include <stddef.h>


// Must be last.

bool UPB_PRIVATE(_upb_Message_NextBaseField)(const upb_Message* msg,
                                             const upb_MiniTable* m,
                                             const upb_MiniTableField** out_f,
                                             upb_MessageValue* out_v,
                                             size_t* iter) {
  const size_t count = upb_MiniTable_FieldCount(m);
  size_t i = *iter;

  while (++i < count) {
    const upb_MiniTableField* f = upb_MiniTable_GetFieldByIndex(m, i);
    const void* src = UPB_PRIVATE(_upb_Message_DataPtr)(msg, f);

    upb_MessageValue val;
    UPB_PRIVATE(_upb_MiniTableField_DataCopy)(f, &val, src);

    // Skip field if unset or empty.
    if (upb_MiniTableField_HasPresence(f)) {
      if (!upb_Message_HasBaseField(msg, f)) continue;
    } else {
      if (UPB_PRIVATE(_upb_MiniTableField_DataIsZero)(f, src)) continue;

      if (upb_MiniTableField_IsArray(f)) {
        if (upb_Array_Size(val.array_val) == 0) continue;
      } else if (upb_MiniTableField_IsMap(f)) {
        if (upb_Map_Size(val.map_val) == 0) continue;
      }
    }

    *out_f = f;
    *out_v = val;
    *iter = i;
    return true;
  }

  return false;
}


#include <stddef.h>
#include <stdint.h>


// Must be last.

typedef struct {
  upb_MdDecoder base;
  upb_Arena* arena;
  upb_MiniTableEnum* enum_table;
  uint32_t enum_value_count;
  uint32_t enum_data_count;
  uint32_t enum_data_capacity;
} upb_MdEnumDecoder;

static size_t upb_MiniTableEnum_Size(uint32_t count) {
  return UPB_SIZEOF_FLEX(upb_MiniTableEnum, UPB_PRIVATE(data), count);
}

static upb_MiniTableEnum* _upb_MiniTable_AddEnumDataMember(upb_MdEnumDecoder* d,
                                                           uint32_t val) {
  if (d->enum_data_count == d->enum_data_capacity) {
    size_t old_sz = upb_MiniTableEnum_Size(d->enum_data_capacity);
    if (d->enum_data_capacity > UINT32_MAX / 2) {
      upb_MdDecoder_ErrorJmp(&d->base, "Out of memory");
    }
    uint32_t new_capacity = UPB_MAX(2, d->enum_data_capacity * 2);
    if (UPB_SIZEOF_FLEX_WOULD_OVERFLOW(upb_MiniTableEnum, UPB_PRIVATE(data),
                                       new_capacity)) {
      upb_MdDecoder_ErrorJmp(&d->base, "Out of memory");
    }
    size_t new_sz = upb_MiniTableEnum_Size(new_capacity);
    d->enum_table = upb_Arena_Realloc(d->arena, d->enum_table, old_sz, new_sz);
    upb_MdDecoder_CheckOutOfMemory(&d->base, d->enum_table);
    d->enum_data_capacity = new_capacity;
  }
  d->enum_table->UPB_PRIVATE(data)[d->enum_data_count++] = val;
  return d->enum_table;
}

static void upb_MiniTableEnum_BuildValue(upb_MdEnumDecoder* d, uint32_t val) {
  upb_MiniTableEnum* table = d->enum_table;
  d->enum_value_count++;
  if (table->UPB_PRIVATE(value_count) ||
      (val > 512 && d->enum_value_count < val / 32)) {
    if (table->UPB_PRIVATE(value_count) == 0) {
      UPB_ASSERT(d->enum_data_count == table->UPB_PRIVATE(mask_limit) / 32);
    }
    table = _upb_MiniTable_AddEnumDataMember(d, val);
    table->UPB_PRIVATE(value_count)++;
  } else {
    uint32_t new_mask_limit = ((val / 32) + 1) * 32;
    while (table->UPB_PRIVATE(mask_limit) < new_mask_limit) {
      table = _upb_MiniTable_AddEnumDataMember(d, 0);
      table->UPB_PRIVATE(mask_limit) += 32;
    }
    table->UPB_PRIVATE(data)[val / 32] |= 1ULL << (val % 32);
  }
}

static upb_MiniTableEnum* upb_MtDecoder_DoBuildMiniTableEnum(
    upb_MdEnumDecoder* d, const char* data, size_t len) {
  // If the string is non-empty then it must begin with a version tag.
  if (len) {
    if (*data != kUpb_EncodedVersion_EnumV1) {
      upb_MdDecoder_ErrorJmp(&d->base, "Invalid enum version: %c", *data);
    }
    data++;
    len--;
  }

  upb_MdDecoder_CheckOutOfMemory(&d->base, d->enum_table);

  // Guarantee at least 64 bits of mask without checking mask size.
  d->enum_table->UPB_PRIVATE(mask_limit) = 64;
  d->enum_table = _upb_MiniTable_AddEnumDataMember(d, 0);
  d->enum_table = _upb_MiniTable_AddEnumDataMember(d, 0);

  d->enum_table->UPB_PRIVATE(value_count) = 0;

  const char* ptr = data;
  uint32_t base = 0;

  while (ptr < d->base.end) {
    char ch = *ptr++;
    if (ch <= kUpb_EncodedValue_MaxEnumMask) {
      uint32_t mask = _upb_FromBase92(ch);
      for (int i = 0; i < 5; i++, base++, mask >>= 1) {
        if (mask & 1) upb_MiniTableEnum_BuildValue(d, base);
      }
    } else if (kUpb_EncodedValue_MinSkip <= ch &&
               ch <= kUpb_EncodedValue_MaxSkip) {
      uint32_t skip;
      ptr = upb_MdDecoder_DecodeBase92Varint(&d->base, ptr, ch,
                                             kUpb_EncodedValue_MinSkip,
                                             kUpb_EncodedValue_MaxSkip, &skip);
      base += skip;
    } else {
      upb_MdDecoder_ErrorJmp(&d->base, "Unexpected character: %c", ch);
    }
  }

  return d->enum_table;
}

static upb_MiniTableEnum* upb_MtDecoder_BuildMiniTableEnum(
    upb_MdEnumDecoder* const decoder, const char* const data,
    size_t const len) {
  if (UPB_SETJMP(decoder->base.err) != 0) return NULL;
  return upb_MtDecoder_DoBuildMiniTableEnum(decoder, data, len);
}

upb_MiniTableEnum* upb_MiniTableEnum_Build(const char* data, size_t len,
                                           upb_Arena* arena,
                                           upb_Status* status) {
  uint32_t initial_capacity = 2;
  upb_MdEnumDecoder decoder = {
      .base =
          {
              .end = UPB_PTRADD(data, len),
              .status = status,
          },
      .arena = arena,
      .enum_table =
          upb_Arena_Malloc(arena, upb_MiniTableEnum_Size(initial_capacity)),
      .enum_value_count = 0,
      .enum_data_count = 0,
      .enum_data_capacity = initial_capacity,
  };

  return upb_MtDecoder_BuildMiniTableEnum(&decoder, data, len);
}


#include <inttypes.h>
#include <stddef.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>


// Our awkward dance for including fasttable only when it is enabled.
#if UPB_FASTTABLE
#define UPB_INCLUDE_FAST_DECODE
#endif

#ifdef UPB_INCLUDE_FAST_DECODE
#endif

#undef UPB_INCLUDE_FAST_DECODE

// Must be last.

// We reserve unused hasbits to make room for upb_Message fields.
#define kUpb_Reserved_Hasbytes sizeof(struct upb_Message)

// 64 is the first hasbit that we currently use.
#define kUpb_Reserved_Hasbits (kUpb_Reserved_Hasbytes * 8)

#define kUpb_OneOfLayoutItem_IndexSentinel ((uint16_t)-1)

// Stores the field number of the present value of the oneof
#define kUpb_OneOf_CaseFieldRep (kUpb_FieldRep_4Byte)

// The maximum field number that can be encoded on the wire.
// Note that this limit does not apply to MessageSet, which can have field
// numbers up to INT32_MAX.
#define kUpb_MaxFieldNumber ((1 << 29) - 1)

typedef struct {
  // Index of the corresponding field. The field's offset will be the index of
  // the next field in a linked list.
  uint16_t field_index;
  // This enum is stored in bytes to avoid trailing padding while preserving
  // two-byte alignment.
  uint8_t /* upb_FieldRep*/ rep;
} upb_OneOfLayoutItem;

typedef struct {
  upb_OneOfLayoutItem* data;
  size_t size;
  size_t buf_capacity_bytes;
} upb_OneOfLayoutItemVector;

typedef struct {
  upb_MdDecoder base;
  upb_MiniTableField* fields;
  upb_MiniTablePlatform platform;
  upb_OneOfLayoutItemVector oneofs;
  upb_Arena* arena;
  // Initially tracks the count of each field rep type; then, during assignment,
  // tracks the base offset for the next processed field of the given rep.
  uint16_t rep_counts_offsets[kUpb_FieldRep_Max + 1];
  uint32_t sub_count;
  bool is_extension;

  // When building fasttables, we don't know the total size of the table until
  // we're done decoding, so we allocate a temporary table on the stack and
  // allocate the real thing from the arena later.
  upb_MiniTable table;
} upb_MtDecoder;

// In each field's offset, we temporarily store a presence classifier:
enum PresenceClass {
  kNoPresence = 0,
  kHasbitPresence = 1,
  kRequiredPresence = 2,
  kOneofBase = 3,
  // Negative values refer to a specific oneof with that number.  Positive
  // values >= kOneofBase indicate that this field is in a oneof, and specify
  // the next field in this oneof's linked list.
};

static bool upb_MtDecoder_FieldIsPackable(upb_MiniTableField* field) {
  return (field->UPB_PRIVATE(mode) & kUpb_FieldMode_Array) &&
         upb_FieldType_IsPackable(field->UPB_PRIVATE(descriptortype));
}

typedef struct {
  uint16_t submsg_count;
  uint16_t subenum_count;
} upb_SubCounts;

static void upb_MiniTable_SetTypeAndSub(upb_MtDecoder* d,
                                        upb_MiniTableField* field,
                                        upb_FieldType type,
                                        uint64_t msg_modifiers,
                                        bool is_proto3_enum) {
  if (is_proto3_enum) {
    UPB_ASSERT(type == kUpb_FieldType_Enum);
    type = kUpb_FieldType_Int32;
    field->UPB_PRIVATE(mode) |= kUpb_LabelFlags_IsAlternate;
  } else if (type == kUpb_FieldType_String &&
             !(msg_modifiers & kUpb_MessageModifier_ValidateUtf8)) {
    type = kUpb_FieldType_Bytes;
    field->UPB_PRIVATE(mode) |= kUpb_LabelFlags_IsAlternate;
  }

  field->UPB_PRIVATE(descriptortype) = type;

  if (upb_MtDecoder_FieldIsPackable(field) &&
      (msg_modifiers & kUpb_MessageModifier_DefaultIsPacked)) {
    field->UPB_PRIVATE(mode) |= kUpb_LabelFlags_IsPacked;
  }

  // We initially set `submsg_ofs` to the index of the sub in the list of subs.
  // Later, we'll update it to be a relative byte offset.
  if (type == kUpb_FieldType_Message || type == kUpb_FieldType_Group ||
      type == kUpb_FieldType_Enum) {
    field->UPB_PRIVATE(submsg_ofs) = d->sub_count++;
  } else {
    field->UPB_PRIVATE(submsg_ofs) = kUpb_NoSub;
  }
}

static const char kUpb_EncodedToType[] = {
    [kUpb_EncodedType_Double] = kUpb_FieldType_Double,
    [kUpb_EncodedType_Float] = kUpb_FieldType_Float,
    [kUpb_EncodedType_Int64] = kUpb_FieldType_Int64,
    [kUpb_EncodedType_UInt64] = kUpb_FieldType_UInt64,
    [kUpb_EncodedType_Int32] = kUpb_FieldType_Int32,
    [kUpb_EncodedType_Fixed64] = kUpb_FieldType_Fixed64,
    [kUpb_EncodedType_Fixed32] = kUpb_FieldType_Fixed32,
    [kUpb_EncodedType_Bool] = kUpb_FieldType_Bool,
    [kUpb_EncodedType_String] = kUpb_FieldType_String,
    [kUpb_EncodedType_Group] = kUpb_FieldType_Group,
    [kUpb_EncodedType_Message] = kUpb_FieldType_Message,
    [kUpb_EncodedType_Bytes] = kUpb_FieldType_Bytes,
    [kUpb_EncodedType_UInt32] = kUpb_FieldType_UInt32,
    [kUpb_EncodedType_OpenEnum] = kUpb_FieldType_Enum,
    [kUpb_EncodedType_SFixed32] = kUpb_FieldType_SFixed32,
    [kUpb_EncodedType_SFixed64] = kUpb_FieldType_SFixed64,
    [kUpb_EncodedType_SInt32] = kUpb_FieldType_SInt32,
    [kUpb_EncodedType_SInt64] = kUpb_FieldType_SInt64,
    [kUpb_EncodedType_ClosedEnum] = kUpb_FieldType_Enum,
};

static void upb_MiniTable_SetField(upb_MtDecoder* d, uint8_t ch,
                                   upb_MiniTableField* field,
                                   uint64_t msg_modifiers) {
  static const char kUpb_EncodedToFieldRep[] = {
      [kUpb_EncodedType_Double] = kUpb_FieldRep_8Byte,
      [kUpb_EncodedType_Float] = kUpb_FieldRep_4Byte,
      [kUpb_EncodedType_Int64] = kUpb_FieldRep_8Byte,
      [kUpb_EncodedType_UInt64] = kUpb_FieldRep_8Byte,
      [kUpb_EncodedType_Int32] = kUpb_FieldRep_4Byte,
      [kUpb_EncodedType_Fixed64] = kUpb_FieldRep_8Byte,
      [kUpb_EncodedType_Fixed32] = kUpb_FieldRep_4Byte,
      [kUpb_EncodedType_Bool] = kUpb_FieldRep_1Byte,
      [kUpb_EncodedType_String] = kUpb_FieldRep_StringView,
      [kUpb_EncodedType_Bytes] = kUpb_FieldRep_StringView,
      [kUpb_EncodedType_UInt32] = kUpb_FieldRep_4Byte,
      [kUpb_EncodedType_OpenEnum] = kUpb_FieldRep_4Byte,
      [kUpb_EncodedType_SFixed32] = kUpb_FieldRep_4Byte,
      [kUpb_EncodedType_SFixed64] = kUpb_FieldRep_8Byte,
      [kUpb_EncodedType_SInt32] = kUpb_FieldRep_4Byte,
      [kUpb_EncodedType_SInt64] = kUpb_FieldRep_8Byte,
      [kUpb_EncodedType_ClosedEnum] = kUpb_FieldRep_4Byte,
  };

  char pointer_rep = d->platform == kUpb_MiniTablePlatform_32Bit
                         ? kUpb_FieldRep_4Byte
                         : kUpb_FieldRep_8Byte;

  int8_t type = _upb_FromBase92(ch);
  if (ch >= _upb_ToBase92(kUpb_EncodedType_RepeatedBase)) {
    type -= kUpb_EncodedType_RepeatedBase;
    field->UPB_PRIVATE(mode) = kUpb_FieldMode_Array;
    field->UPB_PRIVATE(mode) |= pointer_rep << kUpb_FieldRep_Shift;
    field->UPB_PRIVATE(offset) = kNoPresence;
  } else {
    field->UPB_PRIVATE(mode) = kUpb_FieldMode_Scalar;
    field->UPB_PRIVATE(offset) = kHasbitPresence;
    if (type == kUpb_EncodedType_Group || type == kUpb_EncodedType_Message) {
      field->UPB_PRIVATE(mode) |= pointer_rep << kUpb_FieldRep_Shift;
    } else if ((unsigned long)type >= sizeof(kUpb_EncodedToFieldRep)) {
      upb_MdDecoder_ErrorJmp(&d->base, "Invalid field type: %d", (int)type);
    } else {
      field->UPB_PRIVATE(mode) |= kUpb_EncodedToFieldRep[type]
                                  << kUpb_FieldRep_Shift;
    }
  }
  if ((unsigned long)type >= sizeof(kUpb_EncodedToType)) {
    upb_MdDecoder_ErrorJmp(&d->base, "Invalid field type: %d", (int)type);
  }
  upb_MiniTable_SetTypeAndSub(d, field, kUpb_EncodedToType[type], msg_modifiers,
                              type == kUpb_EncodedType_OpenEnum);
}

static void upb_MtDecoder_ModifyField(upb_MtDecoder* d,
                                      uint32_t message_modifiers,
                                      uint32_t field_modifiers,
                                      upb_MiniTableField* field) {
  if (field_modifiers & kUpb_EncodedFieldModifier_FlipPacked) {
    if (!upb_MtDecoder_FieldIsPackable(field)) {
      upb_MdDecoder_ErrorJmp(&d->base,
                             "Cannot flip packed on unpackable field %" PRIu32,
                             upb_MiniTableField_Number(field));
    }
    field->UPB_PRIVATE(mode) ^= kUpb_LabelFlags_IsPacked;
  }

  if (field_modifiers & kUpb_EncodedFieldModifier_FlipValidateUtf8) {
    if (field->UPB_PRIVATE(descriptortype) != kUpb_FieldType_Bytes ||
        !(field->UPB_PRIVATE(mode) & kUpb_LabelFlags_IsAlternate)) {
      upb_MdDecoder_ErrorJmp(&d->base,
                             "Cannot flip ValidateUtf8 on field %" PRIu32
                             ", type=%d, mode=%d",
                             upb_MiniTableField_Number(field),
                             (int)field->UPB_PRIVATE(descriptortype),
                             (int)field->UPB_PRIVATE(mode));
    }
    field->UPB_PRIVATE(descriptortype) = kUpb_FieldType_String;
    field->UPB_PRIVATE(mode) &= ~kUpb_LabelFlags_IsAlternate;
  }

  bool singular = field_modifiers & kUpb_EncodedFieldModifier_IsProto3Singular;
  bool required = field_modifiers & kUpb_EncodedFieldModifier_IsRequired;

  // Validate.
  if ((singular || required) && field->UPB_PRIVATE(offset) != kHasbitPresence) {
    upb_MdDecoder_ErrorJmp(&d->base,
                           "Invalid modifier(s) for repeated field %" PRIu32,
                           upb_MiniTableField_Number(field));
  }
  if (singular && required) {
    upb_MdDecoder_ErrorJmp(
        &d->base, "Field %" PRIu32 " cannot be both singular and required",
        upb_MiniTableField_Number(field));
  }

  if (singular && upb_MiniTableField_IsSubMessage(field)) {
    upb_MdDecoder_ErrorJmp(&d->base,
                           "Field %" PRIu32 " cannot be a singular submessage",
                           upb_MiniTableField_Number(field));
  }

  if (singular) field->UPB_PRIVATE(offset) = kNoPresence;
  if (required) {
    field->UPB_PRIVATE(offset) = kRequiredPresence;
  }
}

static void upb_MtDecoder_PushOneof(upb_MtDecoder* d,
                                    upb_OneOfLayoutItem item) {
  if (item.field_index == kUpb_OneOfLayoutItem_IndexSentinel) {
    upb_MdDecoder_ErrorJmp(&d->base, "Empty oneof");
  }
  if ((d->oneofs.size + 1) * sizeof(*d->oneofs.data) >
      d->oneofs.buf_capacity_bytes) {
    size_t new_cap = UPB_MAX(8, d->oneofs.size * 2) * sizeof(*d->oneofs.data);
    d->oneofs.data =
        upb_grealloc(d->oneofs.data, d->oneofs.buf_capacity_bytes, new_cap);
    upb_MdDecoder_CheckOutOfMemory(&d->base, d->oneofs.data);
    d->oneofs.buf_capacity_bytes = new_cap;
  }
  item.field_index -= kOneofBase;

  d->rep_counts_offsets[kUpb_OneOf_CaseFieldRep]++;
  d->rep_counts_offsets[item.rep]++;
  d->oneofs.data[d->oneofs.size++] = item;
}

static size_t upb_MtDecoder_SizeOfRep(upb_FieldRep rep,
                                      upb_MiniTablePlatform platform) {
  enum { string_view_size_32 = 8, string_view_size_64 = 16 };
  UPB_STATIC_ASSERT(sizeof(upb_StringView) ==
                        UPB_SIZE(string_view_size_32, string_view_size_64),
                    "StringView size mismatch");
  static const uint8_t kRepToSize32[] = {
      [kUpb_FieldRep_1Byte] = 1,
      [kUpb_FieldRep_4Byte] = 4,
      [kUpb_FieldRep_StringView] = string_view_size_32,
      [kUpb_FieldRep_8Byte] = 8,
  };
  static const uint8_t kRepToSize64[] = {
      [kUpb_FieldRep_1Byte] = 1,
      [kUpb_FieldRep_4Byte] = 4,
      [kUpb_FieldRep_StringView] = string_view_size_64,
      [kUpb_FieldRep_8Byte] = 8,
  };
  return platform == kUpb_MiniTablePlatform_32Bit ? kRepToSize32[rep]
                                                  : kRepToSize64[rep];
}

static size_t upb_MtDecoder_AlignOfRep(upb_FieldRep rep,
                                       upb_MiniTablePlatform platform) {
  enum { string_view_align_32 = 4, string_view_align_64 = 8 };
  UPB_STATIC_ASSERT(UPB_ALIGN_OF(upb_StringView) ==
                        UPB_SIZE(string_view_align_32, string_view_align_64),
                    "StringView size mismatch");

  static const uint8_t kRepToAlign32[] = {
      [kUpb_FieldRep_1Byte] = 1,
      [kUpb_FieldRep_4Byte] = 4,
      [kUpb_FieldRep_StringView] = string_view_align_32,
      [kUpb_FieldRep_8Byte] = 8,
  };
  static const uint8_t kRepToAlign64[] = {
      [kUpb_FieldRep_1Byte] = 1,
      [kUpb_FieldRep_4Byte] = 4,
      [kUpb_FieldRep_StringView] = string_view_align_64,
      [kUpb_FieldRep_8Byte] = 8,
  };
  return platform == kUpb_MiniTablePlatform_32Bit ? kRepToAlign32[rep]
                                                  : kRepToAlign64[rep];
}

static const char* upb_MtDecoder_DecodeOneofField(upb_MtDecoder* d,
                                                  const char* ptr,
                                                  char first_ch,
                                                  upb_OneOfLayoutItem* item) {
  uint32_t field_num;
  ptr = upb_MdDecoder_DecodeBase92Varint(
      &d->base, ptr, first_ch, kUpb_EncodedValue_MinOneofField,
      kUpb_EncodedValue_MaxOneofField, &field_num);
  upb_MiniTableField* f =
      (void*)upb_MiniTable_FindFieldByNumber(&d->table, field_num);

  if (!f) {
    upb_MdDecoder_ErrorJmp(&d->base,
                           "Couldn't add field number %" PRIu32
                           " to oneof, no such field number.",
                           field_num);
  }
  if (f->UPB_PRIVATE(offset) != kHasbitPresence) {
    upb_MdDecoder_ErrorJmp(
        &d->base,
        "Cannot add repeated, required, or singular field %" PRIu32
        " to oneof.",
        field_num);
  }

  // Oneof storage must be large enough to accommodate the largest member.
  int rep = f->UPB_PRIVATE(mode) >> kUpb_FieldRep_Shift;
  size_t new_size = upb_MtDecoder_SizeOfRep(rep, d->platform);
  size_t new_align = upb_MtDecoder_AlignOfRep(rep, d->platform);
  size_t current_size = upb_MtDecoder_SizeOfRep(item->rep, d->platform);
  size_t current_align = upb_MtDecoder_AlignOfRep(item->rep, d->platform);

  if (new_size > current_size ||
      (new_size == current_size && new_align > current_align)) {
    UPB_ASSERT(new_align >= current_align);
    item->rep = rep;
  } else {
    UPB_ASSERT(current_align >= new_align);
  }
  // Prepend this field to the linked list.
  f->UPB_PRIVATE(offset) = item->field_index;
  item->field_index = (f - d->fields) + kOneofBase;
  return ptr;
}

static const char* upb_MtDecoder_DecodeOneofs(upb_MtDecoder* d,
                                              const char* ptr) {
  upb_OneOfLayoutItem item = {
      .rep = 0, .field_index = kUpb_OneOfLayoutItem_IndexSentinel};
  while (ptr < d->base.end) {
    char ch = *ptr++;
    if (ch == kUpb_EncodedValue_FieldSeparator) {
      // Field separator, no action needed.
    } else if (ch == kUpb_EncodedValue_OneofSeparator) {
      // End of oneof.
      upb_MtDecoder_PushOneof(d, item);
      item.field_index =
          kUpb_OneOfLayoutItem_IndexSentinel;  // Move to next oneof.
    } else {
      ptr = upb_MtDecoder_DecodeOneofField(d, ptr, ch, &item);
    }
  }

  // Push final oneof.
  upb_MtDecoder_PushOneof(d, item);
  return ptr;
}

static const char* upb_MtDecoder_ParseModifier(upb_MtDecoder* d,
                                               const char* ptr, char first_ch,
                                               upb_MiniTableField* last_field,
                                               uint64_t* msg_modifiers) {
  uint32_t mod;
  ptr = upb_MdDecoder_DecodeBase92Varint(&d->base, ptr, first_ch,
                                         kUpb_EncodedValue_MinModifier,
                                         kUpb_EncodedValue_MaxModifier, &mod);
  if (last_field) {
    upb_MtDecoder_ModifyField(d, *msg_modifiers, mod, last_field);
  } else {
    if (d->is_extension) {
      upb_MdDecoder_ErrorJmp(&d->base,
                             "Extensions cannot have message modifiers");
    }
    *msg_modifiers = mod;
  }

  return ptr;
}

size_t upb_MtDecoder_PtrSize(upb_MtDecoder* d) {
  return d->platform == kUpb_MiniTablePlatform_32Bit ? 4 : 8;
}

static void upb_MtDecoder_AllocateSubs(upb_MtDecoder* d,
                                       upb_MiniTableSubInternal* subs) {
  // The `ofs` variable tracks byte offset between the current field and the
  // current entry in the `subs` array. Whenever we move to the next entry in
  // the `fields` array, the offset decreases by the size of the field, but
  // whenever we move to the next entry in the `subs` array, the offset
  // *increases* by the size of the entry in the `subs` array.
  UPB_ASSERT((char*)subs >= (char*)d->fields);
  size_t ofs = (char*)subs - (char*)d->fields;
  uintptr_t ptr_size = upb_MtDecoder_PtrSize(d);
  for (int i = 0; i < d->table.UPB_PRIVATE(field_count);
       i++, ofs -= sizeof(upb_MiniTableField)) {
    upb_MiniTableField* f = &d->fields[i];
    if (f->UPB_PRIVATE(submsg_ofs) == kUpb_NoSub) continue;
    size_t u32_ofs = ofs / kUpb_SubmsgOffsetBytes;
    UPB_ASSERT((ofs % 4) == 0);
    UPB_ASSERT((i * sizeof(upb_MiniTableField) + ofs) % ptr_size == 0);
    if (u32_ofs > UINT16_MAX) {
      upb_MdDecoder_ErrorJmp(&d->base, "Submessage offset overflow");
    }
    f->UPB_PRIVATE(submsg_ofs) = u32_ofs;
    ofs += ptr_size;
  }
}

static const char* upb_MtDecoder_Parse(upb_MtDecoder* d, const char* ptr,
                                       size_t len, void* fields,
                                       size_t field_size,
                                       uint16_t* field_count) {
  uint64_t msg_modifiers = 0;
  uint32_t last_field_number = 0;
  upb_MiniTableField* last_field = NULL;
  bool need_dense_below = !d->is_extension;

  d->base.end = UPB_PTRADD(ptr, len);

  while (ptr < d->base.end) {
    char ch = *ptr++;
    if (ch <= kUpb_EncodedValue_MaxField) {
      if (d->is_extension && last_field) {
        // For extensions, consume only a single field and then return.
        return --ptr;
      }
      upb_MiniTableField* field = fields;
      *field_count += 1;
      fields = (char*)fields + field_size;
      uint32_t number = ++last_field_number;
      if (number == 0 || (number > kUpb_MaxFieldNumber && !d->is_extension)) {
        upb_MdDecoder_ErrorJmp(&d->base, "Invalid field number: %" PRIu32,
                               number);
      }
      field->UPB_PRIVATE(number) = number;
      last_field = field;
      upb_MiniTable_SetField(d, ch, field, msg_modifiers);
    } else if (kUpb_EncodedValue_MinModifier <= ch &&
               ch <= kUpb_EncodedValue_MaxModifier) {
      ptr = upb_MtDecoder_ParseModifier(d, ptr, ch, last_field, &msg_modifiers);
      if (msg_modifiers & kUpb_MessageModifier_IsExtendable) {
        d->table.UPB_PRIVATE(ext) |= kUpb_ExtMode_Extendable;
      }
    } else if (ch == kUpb_EncodedValue_End) {
      if (d->is_extension) {
        upb_MdDecoder_ErrorJmp(&d->base, "Extensions cannot have oneofs.");
      }
      ptr = upb_MtDecoder_DecodeOneofs(d, ptr);
    } else if (kUpb_EncodedValue_MinSkip <= ch &&
               ch <= kUpb_EncodedValue_MaxSkip) {
      if (need_dense_below) {
        d->table.UPB_PRIVATE(dense_below) = d->table.UPB_PRIVATE(field_count);
        need_dense_below = false;
      }
      uint32_t skip;
      ptr = upb_MdDecoder_DecodeBase92Varint(&d->base, ptr, ch,
                                             kUpb_EncodedValue_MinSkip,
                                             kUpb_EncodedValue_MaxSkip, &skip);
      last_field_number += skip;
      last_field_number--;  // Next field seen will increment.
    } else {
      upb_MdDecoder_ErrorJmp(&d->base, "Invalid char: %c", ch);
    }
  }

  if (need_dense_below) {
    d->table.UPB_PRIVATE(dense_below) = d->table.UPB_PRIVATE(field_count);
  }

  return ptr;
}

static void upb_MtDecoder_ParseMessage(upb_MtDecoder* d, const char* data,
                                       size_t len) {
  const size_t bytes_per_field =
      sizeof(upb_MiniTableField) + sizeof(upb_MiniTableSubInternal);
  // Buffer length is an upper bound on the number of fields. We will return
  // what we don't use.
  if ((SIZE_MAX - 4) / bytes_per_field < len) {
    upb_MdDecoder_ErrorJmp(&d->base, "MiniDescriptor is too large");
  }
  // Max size used per field is a upb_MiniTableField and a
  // upb_MiniTableSubInternal.  There could also be up to 4 bytes of padding,
  // since sizeof(upb_MiniTableField) == 12 and
  // alignof(upb_MiniTableSubInternal) == 8.
  UPB_STATIC_ASSERT(UPB_ALIGN_OF(upb_MiniTableSubInternal) -
                            UPB_ALIGN_OF(upb_MiniTableField) <=
                        4,
                    "alignment difference is too large");
  const size_t initial_bytes = bytes_per_field * len + 4;
  d->fields = upb_Arena_Malloc(d->arena, initial_bytes);
  upb_MdDecoder_CheckOutOfMemory(&d->base, d->fields);

  d->table.UPB_PRIVATE(field_count) = 0;
  d->table.UPB_PRIVATE(fields) = d->fields;
  upb_MtDecoder_Parse(d, data, len, d->fields, sizeof(*d->fields),
                      &d->table.UPB_PRIVATE(field_count));
  size_t field_bytes =
      UPB_ALIGN_UP(d->table.UPB_PRIVATE(field_count) * sizeof(*d->fields),
                   upb_MtDecoder_PtrSize(d));
  upb_MiniTableSubInternal* subs =
      UPB_PTR_AT(d->fields, field_bytes, upb_MiniTableSubInternal);
  memset(subs, 0, sizeof(upb_MiniTableSubInternal) * d->sub_count);

  // We now know how much space we actually used, so shrink the allocation to
  // that size.
  size_t final_bytes =
      field_bytes + sizeof(upb_MiniTableSubInternal) * d->sub_count;
  upb_Arena_ShrinkLast(d->arena, d->fields, initial_bytes, final_bytes);
  upb_MtDecoder_AllocateSubs(d, subs);
}

static void upb_MtDecoder_CalculateAlignments(upb_MtDecoder* d) {
  // Add alignment counts for non-oneof fields (oneofs were added already)
  int n = d->table.UPB_PRIVATE(field_count);
  for (int i = 0; i < n; i++) {
    upb_MiniTableField* f = &d->fields[i];
    if (f->UPB_PRIVATE(offset) >= kOneofBase) continue;
    d->rep_counts_offsets[f->UPB_PRIVATE(mode) >> kUpb_FieldRep_Shift]++;
  }

  // Reserve properly aligned space for each type of field representation
  // present in this message. When we iterate over the fields, they will obtain
  // their offset from within the region matching their alignment requirements.
  size_t base = d->table.UPB_PRIVATE(size);
  // Start with the lowest alignment requirement, going up, because:
  // 1. If there are presence bits, we won't be aligned to start, but adding
  //    some lower-alignment fields may get us closer without wasting space to
  //    padding.
  // 2. The allocator enforces 8 byte alignment, so moving intermediate padding
  //    to trailing padding doesn't save us anything.
  for (upb_FieldRep rep = kUpb_FieldRep_1Byte; rep <= kUpb_FieldRep_Max;
       rep++) {
    uint16_t count = d->rep_counts_offsets[rep];
    if (count) {
      base = UPB_ALIGN_UP(base, upb_MtDecoder_AlignOfRep(rep, d->platform));
      // This entry now tracks the base offset for this field representation
      // type, instead of the count
      d->rep_counts_offsets[rep] = base;
      base += upb_MtDecoder_SizeOfRep(rep, d->platform) * count;
    }
  }
  static const size_t max = UINT16_MAX;
  if (base > max) {
    upb_MdDecoder_ErrorJmp(
        &d->base, "Message size exceeded maximum size of %zu bytes", max);
  }
  d->table.UPB_PRIVATE(size) = (uint16_t)base;
}

static size_t upb_MiniTable_DivideRoundUp(size_t n, size_t d) {
  return (n + d - 1) / d;
}

static void upb_MtDecoder_AssignHasbits(upb_MtDecoder* d) {
  int n = d->table.UPB_PRIVATE(field_count);
  size_t last_hasbit = kUpb_Reserved_Hasbits - 1;

  // First assign required fields, which must have the lowest hasbits.
  for (int i = 0; i < n; i++) {
    upb_MiniTableField* field =
        (upb_MiniTableField*)&d->table.UPB_PRIVATE(fields)[i];
    if (field->UPB_PRIVATE(offset) == kRequiredPresence) {
      field->presence = ++last_hasbit;
    } else if (field->UPB_PRIVATE(offset) == kNoPresence) {
      field->presence = 0;
    }
  }
  if (last_hasbit >= kUpb_Reserved_Hasbits + 63) {
    upb_MdDecoder_ErrorJmp(&d->base, "Too many required fields");
  }

  d->table.UPB_PRIVATE(required_count) =
      last_hasbit - (kUpb_Reserved_Hasbits - 1);
  UPB_ASSERT(d->table.UPB_PRIVATE(required_count) < 64);

  // Next assign non-required hasbit fields.
  for (int i = 0; i < n; i++) {
    upb_MiniTableField* field =
        (upb_MiniTableField*)&d->table.UPB_PRIVATE(fields)[i];
    if (field->UPB_PRIVATE(offset) == kHasbitPresence) {
      field->presence = ++last_hasbit;
    }
  }

  d->table.UPB_PRIVATE(size) =
      last_hasbit ? upb_MiniTable_DivideRoundUp(last_hasbit + 1, 8) : 0;
}

static size_t upb_MtDecoder_Place(upb_MtDecoder* d, upb_FieldRep rep) {
  size_t size = upb_MtDecoder_SizeOfRep(rep, d->platform);
  size_t offset = d->rep_counts_offsets[rep];
  d->rep_counts_offsets[rep] += size;
  return offset;
}

static void upb_MtDecoder_AssignOffsets(upb_MtDecoder* d) {
  upb_MiniTableField* field_end =
      UPB_PTRADD(d->fields, d->table.UPB_PRIVATE(field_count));
  for (upb_MiniTableField* field = d->fields; field < field_end; field++) {
    if (field->UPB_PRIVATE(offset) >= kOneofBase) continue;
    field->UPB_PRIVATE(offset) =
        upb_MtDecoder_Place(d, field->UPB_PRIVATE(mode) >> kUpb_FieldRep_Shift);
  }

  upb_OneOfLayoutItem* oneof_end = UPB_PTRADD(d->oneofs.data, d->oneofs.size);

  for (upb_OneOfLayoutItem* item = d->oneofs.data; item < oneof_end; item++) {
    upb_MiniTableField* f = &d->fields[item->field_index];
    uint16_t case_offset = upb_MtDecoder_Place(d, kUpb_OneOf_CaseFieldRep);
    uint16_t data_offset = upb_MtDecoder_Place(d, item->rep);
    while (true) {
      f->presence = ~case_offset;
      uint16_t next_offset = f->UPB_PRIVATE(offset);
      f->UPB_PRIVATE(offset) = data_offset;
      if (next_offset == kUpb_OneOfLayoutItem_IndexSentinel) break;
      UPB_ASSERT(next_offset - kOneofBase < d->table.UPB_PRIVATE(field_count));
      f = &d->fields[next_offset - kOneofBase];
    }
  }

  // Since messages are always allocated on arenas, we can save repeatedly
  // realigning by doing alignment at minitable construction time. We don't want
  // to align to UPB_MALLOC_ALIGN because it can change with sanitizers, and if
  // we're generating code we don't want to calculate size differently depending
  // on the proto compiler's host or build configuration.
  d->table.UPB_PRIVATE(size) =
      UPB_ALIGN_UP(d->table.UPB_PRIVATE(size), kUpb_Message_Align);
}

static void upb_MtDecoder_ValidateEntryField(upb_MtDecoder* d,
                                             const upb_MiniTableField* f,
                                             uint32_t expected_num) {
  const char* name = expected_num == 1 ? "key" : "val";
  const uint32_t f_number = upb_MiniTableField_Number(f);
  if (f_number != expected_num) {
    upb_MdDecoder_ErrorJmp(&d->base,
                           "map %s did not have expected number (%d vs %d)",
                           name, expected_num, f_number);
  }

  if (!upb_MiniTableField_IsScalar(f)) {
    upb_MdDecoder_ErrorJmp(
        &d->base, "map %s cannot be repeated or map, or be in oneof", name);
  }

  uint32_t not_ok_types;
  if (expected_num == 1) {
    not_ok_types = (1 << kUpb_FieldType_Float) | (1 << kUpb_FieldType_Double) |
                   (1 << kUpb_FieldType_Message) | (1 << kUpb_FieldType_Group) |
                   (1 << kUpb_FieldType_Bytes) | (1 << kUpb_FieldType_Enum);
  } else {
    not_ok_types = 1 << kUpb_FieldType_Group;
  }

  if ((1 << upb_MiniTableField_Type(f)) & not_ok_types) {
    upb_MdDecoder_ErrorJmp(&d->base, "map %s cannot have type %d", name,
                           (int)f->UPB_PRIVATE(descriptortype));
  }
}

static void upb_MtDecoder_ParseMap(upb_MtDecoder* d, const char* data,
                                   size_t len) {
  upb_MtDecoder_ParseMessage(d, data, len);
  upb_MtDecoder_AssignHasbits(d);

  if (UPB_UNLIKELY(d->table.UPB_PRIVATE(field_count) != 2)) {
    upb_MdDecoder_ErrorJmp(&d->base, "%hu fields in map",
                           d->table.UPB_PRIVATE(field_count));
    UPB_UNREACHABLE();
  }

  if (d->oneofs.size != 0) {
    upb_MdDecoder_ErrorJmp(&d->base, "Map entry cannot have oneof");
  }

  upb_MtDecoder_ValidateEntryField(d, &d->table.UPB_PRIVATE(fields)[0], 1);
  upb_MtDecoder_ValidateEntryField(d, &d->table.UPB_PRIVATE(fields)[1], 2);

  d->fields[0].UPB_PRIVATE(offset) = offsetof(upb_MapEntry, k);
  d->fields[1].UPB_PRIVATE(offset) = offsetof(upb_MapEntry, v);
  d->table.UPB_PRIVATE(size) = sizeof(upb_MapEntry);

  // Map entries have a special bit set to signal it's a map entry, used in
  // upb_MiniTable_SetSubMessage() below.
  d->table.UPB_PRIVATE(ext) |= kUpb_ExtMode_IsMapEntry;
}

static void upb_MtDecoder_ParseMessageSet(upb_MtDecoder* d, const char* data,
                                          size_t len) {
  if (len > 0) {
    upb_MdDecoder_ErrorJmp(&d->base, "Invalid message set encode length: %zu",
                           len);
  }

  upb_MiniTable* ret = &d->table;
  ret->UPB_PRIVATE(size) = kUpb_Reserved_Hasbytes;
  ret->UPB_PRIVATE(field_count) = 0;
  ret->UPB_PRIVATE(ext) = kUpb_ExtMode_IsMessageSet;
  ret->UPB_PRIVATE(dense_below) = 0;
  ret->UPB_PRIVATE(table_mask) = -1;
  ret->UPB_PRIVATE(required_count) = 0;
}

static upb_MiniTable* upb_MtDecoder_DoBuildMiniTableWithBuf(
    upb_MtDecoder* decoder, const char* data, size_t len, void** buf,
    size_t* buf_size) {
  decoder->table.UPB_PRIVATE(size) = kUpb_Reserved_Hasbytes;
  decoder->table.UPB_PRIVATE(field_count) = 0;
  decoder->table.UPB_PRIVATE(ext) = kUpb_ExtMode_NonExtendable;
  decoder->table.UPB_PRIVATE(dense_below) = 0;
  decoder->table.UPB_PRIVATE(table_mask) = -1;
  decoder->table.UPB_PRIVATE(required_count) = 0;
#ifdef UPB_TRACING_ENABLED
  // MiniTables built from MiniDescriptors will not be able to vend the message
  // name unless it is explicitly set with upb_MiniTable_SetFullName().
  decoder->table.UPB_PRIVATE(full_name) = 0;
#endif

  // Strip off and verify the version tag.
  if (!len--) goto done;
  const char vers = *data++;

  switch (vers) {
    case kUpb_EncodedVersion_MapV1:
      upb_MtDecoder_ParseMap(decoder, data, len);
      break;

    case kUpb_EncodedVersion_MessageV1:
      upb_MtDecoder_ParseMessage(decoder, data, len);
      upb_MtDecoder_AssignHasbits(decoder);
      upb_MtDecoder_CalculateAlignments(decoder);
      upb_MtDecoder_AssignOffsets(decoder);
      break;

    case kUpb_EncodedVersion_MessageSetV1:
      upb_MtDecoder_ParseMessageSet(decoder, data, len);
      break;

    default:
      upb_MdDecoder_ErrorJmp(&decoder->base, "Invalid message version: %c",
                             vers);
  }

done:
  *buf = decoder->oneofs.data;
  *buf_size = decoder->oneofs.buf_capacity_bytes;
  size_t mt_size = sizeof(upb_MiniTable);

#if UPB_FASTTABLE
  upb_DecodeFast_TableEntry fasttable[32];
  int fasttable_size = upb_DecodeFast_BuildTable(&decoder->table, fasttable);
  mt_size += fasttable_size * sizeof(fasttable[0]);
#endif

  upb_MiniTable* ret = upb_Arena_Malloc(decoder->arena, mt_size);
  memcpy(ret, &decoder->table, sizeof(*ret));

#if UPB_FASTTABLE
  ret->UPB_PRIVATE(table_mask) = upb_DecodeFast_GetTableMask(fasttable_size);
  for (int i = 0; i < fasttable_size; i++) {
    ret->UPB_PRIVATE(fasttable)[i].field_data = fasttable[i].function_data;
    ret->UPB_PRIVATE(fasttable)[i].field_parser =
        upb_DecodeFast_GetFunctionPointer(fasttable[i].function_idx);
  }
#endif
  UPB_PRIVATE(upb_MiniTable_CheckInvariants)(ret);
  return ret;
}

static upb_MiniTable* upb_MtDecoder_BuildMiniTableWithBuf(
    upb_MtDecoder* const decoder, const char* const data, const size_t len,
    void** const buf, size_t* const buf_size) {
  if (UPB_SETJMP(decoder->base.err) != 0) {
    *buf = decoder->oneofs.data;
    *buf_size = decoder->oneofs.buf_capacity_bytes;
    return NULL;
  }

  return upb_MtDecoder_DoBuildMiniTableWithBuf(decoder, data, len, buf,
                                               buf_size);
}

upb_MiniTable* upb_MiniTable_BuildWithBuf(const char* data, size_t len,
                                          upb_MiniTablePlatform platform,
                                          upb_Arena* arena, void** buf,
                                          size_t* buf_size,
                                          upb_Status* status) {
  upb_MtDecoder decoder = {
      .base = {.status = status},
      .platform = platform,
      .sub_count = 0,
      .is_extension = false,
      .oneofs =
          {
              .data = *buf,
              .buf_capacity_bytes = *buf_size,
              .size = 0,
          },
      .arena = arena,
  };

  return upb_MtDecoder_BuildMiniTableWithBuf(&decoder, data, len, buf,
                                             buf_size);
}

static const char* upb_MtDecoder_DoBuildMiniTableExtension(
    upb_MtDecoder* decoder, const char* data, size_t len,
    upb_MiniTableExtension* ext, const upb_MiniTable* extendee,
    upb_MiniTableSub sub) {
  if (!(extendee->UPB_PRIVATE(ext) &
        (kUpb_ExtMode_Extendable | kUpb_ExtMode_IsMessageSet))) {
    upb_MdDecoder_ErrorJmp(&decoder->base, "Extendee is not extendable");
  }

  // If the string is non-empty then it must begin with a version tag.
  if (len) {
    if (*data != kUpb_EncodedVersion_ExtensionV1) {
      upb_MdDecoder_ErrorJmp(&decoder->base, "Invalid ext version: %c", *data);
    }
    data++;
    len--;
  }

  uint16_t count = 0;
  const char* ret =
      upb_MtDecoder_Parse(decoder, data, len, ext, sizeof(*ext), &count);
  if (!ret || count != 1) return NULL;

  upb_MiniTableField* f = &ext->UPB_PRIVATE(field);

  f->UPB_PRIVATE(mode) |= kUpb_LabelFlags_IsExtension;
  f->UPB_PRIVATE(offset) = 0;
  f->presence = 0;

  // In upb_MiniTableExtension, the `sub` member is a pointer-sized member that
  // directly follows the `field` member.
  f->UPB_PRIVATE(submsg_ofs) =
      UPB_ALIGN_UP(sizeof(upb_MiniTableField), upb_MtDecoder_PtrSize(decoder)) /
      kUpb_SubmsgOffsetBytes;

  if (extendee->UPB_PRIVATE(ext) & kUpb_ExtMode_IsMessageSet) {
    // Extensions of MessageSet must be messages.
    if (!upb_MiniTableField_IsSubMessage(f)) return NULL;

    // Extensions of MessageSet must be non-repeating.
    if (upb_MiniTableField_IsArray(f)) return NULL;
  }

  ext->UPB_PRIVATE(extendee) = extendee;
  ext->UPB_PRIVATE(sub) = sub;

  return ret;
}

static const char* upb_MtDecoder_BuildMiniTableExtension(
    upb_MtDecoder* const decoder, const char* const data, const size_t len,
    upb_MiniTableExtension* const ext, const upb_MiniTable* const extendee,
    const upb_MiniTableSub sub) {
  if (UPB_SETJMP(decoder->base.err) != 0) return NULL;
  return upb_MtDecoder_DoBuildMiniTableExtension(decoder, data, len, ext,
                                                 extendee, sub);
}

const char* _upb_MiniTableExtension_Init(const char* data, size_t len,
                                         upb_MiniTableExtension* ext,
                                         const upb_MiniTable* extendee,
                                         upb_MiniTableSub sub,
                                         upb_MiniTablePlatform platform,
                                         upb_Status* status) {
  upb_MtDecoder decoder = {
      .base = {.status = status},
      .arena = NULL,
      .platform = platform,
      .sub_count = 0,
      .is_extension = true,
  };

  return upb_MtDecoder_BuildMiniTableExtension(&decoder, data, len, ext,
                                               extendee, sub);
}

upb_MiniTableExtension* _upb_MiniTableExtension_Build(
    const char* data, size_t len, const upb_MiniTable* extendee,
    upb_MiniTableSub sub, upb_MiniTablePlatform platform, upb_Arena* arena,
    upb_Status* status) {
  upb_MiniTableExtension* ext =
      upb_Arena_Malloc(arena, sizeof(upb_MiniTableExtension));
  if (UPB_UNLIKELY(!ext)) return NULL;

  const char* ptr = _upb_MiniTableExtension_Init(data, len, ext, extendee, sub,
                                                 platform, status);
  if (UPB_UNLIKELY(!ptr)) return NULL;

  return ext;
}

upb_MiniTable* _upb_MiniTable_Build(const char* data, size_t len,
                                    upb_MiniTablePlatform platform,
                                    upb_Arena* arena, upb_Status* status) {
  void* buf = NULL;
  size_t size = 0;
  upb_MiniTable* ret = upb_MiniTable_BuildWithBuf(data, len, platform, arena,
                                                  &buf, &size, status);
  upb_gfree(buf);
  return ret;
}


#include <stddef.h>
#include <stdint.h>
#include <string.h>


// Must be last.

bool upb_MiniTable_SetSubMessage(upb_MiniTable* table,
                                 upb_MiniTableField* field,
                                 const upb_MiniTable* sub) {
  UPB_ASSERT((uintptr_t)table->UPB_PRIVATE(fields) <= (uintptr_t)field &&
             (uintptr_t)field < (uintptr_t)(table->UPB_PRIVATE(fields) +
                                            table->UPB_PRIVATE(field_count)));
  UPB_ASSERT(sub);

  const bool sub_is_map = sub->UPB_PRIVATE(ext) & kUpb_ExtMode_IsMapEntry;

  switch (field->UPB_PRIVATE(descriptortype)) {
    case kUpb_FieldType_Message:
      if (sub_is_map) {
        const bool table_is_map =
            table->UPB_PRIVATE(ext) & kUpb_ExtMode_IsMapEntry;
        if (UPB_UNLIKELY(table_is_map)) return false;

        field->UPB_PRIVATE(mode) =
            (field->UPB_PRIVATE(mode) & ~kUpb_FieldMode_Mask) |
            kUpb_FieldMode_Map;
      }
      break;

    case kUpb_FieldType_Group:
      if (UPB_UNLIKELY(sub_is_map)) return false;
      break;

    default:
      return false;
  }

  upb_MiniTableSubInternal* table_sub =
      UPB_PTR_AT(field, field->UPB_PRIVATE(submsg_ofs) * kUpb_SubmsgOffsetBytes,
                 upb_MiniTableSubInternal);
  // TODO: Add this assert back once YouTube is updated to not call
  // this function repeatedly.
  // UPB_ASSERT(upb_MiniTable_GetSubMessageTable(table, field) == NULL);
  table_sub->UPB_PRIVATE(submsg) = sub;
  return true;
}

bool upb_MiniTable_SetSubEnum(upb_MiniTable* table, upb_MiniTableField* field,
                              const upb_MiniTableEnum* sub) {
  UPB_ASSERT((uintptr_t)table->UPB_PRIVATE(fields) <= (uintptr_t)field &&
             (uintptr_t)field < (uintptr_t)(table->UPB_PRIVATE(fields) +
                                            table->UPB_PRIVATE(field_count)));
  UPB_ASSERT(sub);

  if (field->UPB_PRIVATE(descriptortype) != kUpb_FieldType_Enum) {
    return false;
  }

  if ((table->UPB_PRIVATE(ext) & kUpb_ExtMode_IsMapEntry) &&
      !upb_MiniTableEnum_CheckValue(sub, 0)) {
    // An enum used in a map must include 0 as a value.  This matches a check
    // performed in protoc ("Enum value in map must define 0 as the first
    // value").  Protoc should ensure that we never get here.
    //
    // This ends up being important if we receive wire messages where a map
    // entry omits the value (and thus defaults to 0).
    return false;
  }

  upb_MiniTableSubInternal* table_sub =
      UPB_PTR_AT(field, field->UPB_PRIVATE(submsg_ofs) * kUpb_SubmsgOffsetBytes,
                 upb_MiniTableSubInternal);
  *table_sub = upb_MiniTableSub_FromEnum(sub);
  return true;
}

uint32_t upb_MiniTable_GetSubList(const upb_MiniTable* m,
                                  const upb_MiniTableField** subs) {
  uint32_t msg_count = 0;
  uint32_t enum_count = 0;

  for (int i = 0; i < upb_MiniTable_FieldCount(m); i++) {
    const upb_MiniTableField* f = upb_MiniTable_GetFieldByIndex(m, i);
    if (upb_MiniTableField_CType(f) == kUpb_CType_Message) {
      *subs = f;
      ++subs;
      msg_count++;
    }
  }

  for (int i = 0; i < upb_MiniTable_FieldCount(m); i++) {
    const upb_MiniTableField* f = upb_MiniTable_GetFieldByIndex(m, i);
    if (upb_MiniTableField_IsClosedEnum(f)) {
      *subs = f;
      ++subs;
      enum_count++;
    }
  }

  return (msg_count << 16) | enum_count;
}

// The list of sub_tables and sub_enums must exactly match the number and order
// of sub-message fields and sub-enum fields given by upb_MiniTable_GetSubList()
// above.
bool upb_MiniTable_Link(upb_MiniTable* m, const upb_MiniTable** sub_tables,
                        size_t sub_table_count,
                        const upb_MiniTableEnum** sub_enums,
                        size_t sub_enum_count) {
  uint32_t msg_count = 0;
  uint32_t enum_count = 0;

  for (int i = 0; i < upb_MiniTable_FieldCount(m); i++) {
    upb_MiniTableField* f =
        (upb_MiniTableField*)upb_MiniTable_GetFieldByIndex(m, i);
    if (upb_MiniTableField_CType(f) == kUpb_CType_Message) {
      const upb_MiniTable* sub = sub_tables[msg_count++];
      if (msg_count > sub_table_count) return false;
      if (sub && !upb_MiniTable_SetSubMessage(m, f, sub)) return false;
    }
  }

  for (int i = 0; i < upb_MiniTable_FieldCount(m); i++) {
    upb_MiniTableField* f =
        (upb_MiniTableField*)upb_MiniTable_GetFieldByIndex(m, i);
    if (upb_MiniTableField_IsClosedEnum(f)) {
      const upb_MiniTableEnum* sub = sub_enums[enum_count++];
      if (enum_count > sub_enum_count) return false;
      if (sub && !upb_MiniTable_SetSubEnum(m, f, sub)) return false;
    }
  }

  return (msg_count == sub_table_count) && (enum_count == sub_enum_count);
}


const char _kUpb_ToBase92[] = {
    ' ', '!', '#', '$', '%', '&', '(', ')', '*', '+', ',', '-', '.', '/',
    '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', ':', ';', '<', '=',
    '>', '?', '@', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K',
    'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y',
    'Z', '[', ']', '^', '_', '`', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h',
    'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
    'w', 'x', 'y', 'z', '{', '|', '}', '~',
};

const int8_t _kUpb_FromBase92[] = {
    0,  1,  -1, 2,  3,  4,  5,  -1, 6,  7,  8,  9,  10, 11, 12, 13, 14, 15, 16,
    17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35,
    36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54,
    55, 56, 57, -1, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72,
    73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91,
};


#include <assert.h>
#include <stddef.h>
#include <stdint.h>


// Must be last.

typedef struct {
  uint64_t present_values_mask;
  uint32_t last_written_value;
} upb_MtDataEncoderInternal_EnumState;

typedef struct {
  uint64_t msg_modifiers;
  uint32_t last_field_num;
  enum {
    kUpb_OneofState_NotStarted,
    kUpb_OneofState_StartedOneof,
    kUpb_OneofState_EmittedOneofField,
  } oneof_state;
} upb_MtDataEncoderInternal_MsgState;

typedef struct {
  char* buf_start;  // Only for checking kUpb_MtDataEncoder_MinSize.
  union {
    upb_MtDataEncoderInternal_EnumState enum_state;
    upb_MtDataEncoderInternal_MsgState msg_state;
  } state;
} upb_MtDataEncoderInternal;

static upb_MtDataEncoderInternal* upb_MtDataEncoder_GetInternal(
    upb_MtDataEncoder* e, char* buf_start) {
  UPB_ASSERT(sizeof(upb_MtDataEncoderInternal) <= sizeof(e->internal));
  upb_MtDataEncoderInternal* ret = (upb_MtDataEncoderInternal*)e->internal;
  ret->buf_start = buf_start;
  return ret;
}

static char* upb_MtDataEncoder_PutRaw(upb_MtDataEncoder* e, char* ptr,
                                      char ch) {
  upb_MtDataEncoderInternal* in = (upb_MtDataEncoderInternal*)e->internal;
  UPB_ASSERT(ptr - in->buf_start < kUpb_MtDataEncoder_MinSize);
  if (ptr == e->end) return NULL;
  *ptr++ = ch;
  return ptr;
}

static char* upb_MtDataEncoder_Put(upb_MtDataEncoder* e, char* ptr, char ch) {
  return upb_MtDataEncoder_PutRaw(e, ptr, _upb_ToBase92(ch));
}

static char* upb_MtDataEncoder_PutBase92Varint(upb_MtDataEncoder* e, char* ptr,
                                               uint32_t val, int min, int max) {
  int shift = upb_Log2Ceiling(_upb_FromBase92(max) - _upb_FromBase92(min) + 1);
  UPB_ASSERT(shift <= 6);
  uint32_t mask = (1 << shift) - 1;
  do {
    uint32_t bits = val & mask;
    ptr = upb_MtDataEncoder_Put(e, ptr, bits + _upb_FromBase92(min));
    if (!ptr) return NULL;
    val >>= shift;
  } while (val);
  return ptr;
}

char* upb_MtDataEncoder_PutModifier(upb_MtDataEncoder* e, char* ptr,
                                    uint64_t mod) {
  if (mod) {
    ptr = upb_MtDataEncoder_PutBase92Varint(e, ptr, mod,
                                            kUpb_EncodedValue_MinModifier,
                                            kUpb_EncodedValue_MaxModifier);
  }
  return ptr;
}

char* upb_MtDataEncoder_EncodeExtension(upb_MtDataEncoder* e, char* ptr,
                                        upb_FieldType type, uint32_t field_num,
                                        uint64_t field_mod) {
  upb_MtDataEncoderInternal* in = upb_MtDataEncoder_GetInternal(e, ptr);
  in->state.msg_state.msg_modifiers = 0;
  in->state.msg_state.last_field_num = 0;
  in->state.msg_state.oneof_state = kUpb_OneofState_NotStarted;

  ptr = upb_MtDataEncoder_PutRaw(e, ptr, kUpb_EncodedVersion_ExtensionV1);
  if (!ptr) return NULL;

  return upb_MtDataEncoder_PutField(e, ptr, type, field_num, field_mod);
}

char* upb_MtDataEncoder_EncodeMap(upb_MtDataEncoder* e, char* ptr,
                                  upb_FieldType key_type,
                                  upb_FieldType value_type, uint64_t key_mod,
                                  uint64_t value_mod) {
  upb_MtDataEncoderInternal* in = upb_MtDataEncoder_GetInternal(e, ptr);
  in->state.msg_state.msg_modifiers = 0;
  in->state.msg_state.last_field_num = 0;
  in->state.msg_state.oneof_state = kUpb_OneofState_NotStarted;

  ptr = upb_MtDataEncoder_PutRaw(e, ptr, kUpb_EncodedVersion_MapV1);
  if (!ptr) return NULL;

  ptr = upb_MtDataEncoder_PutField(e, ptr, key_type, 1, key_mod);
  if (!ptr) return NULL;

  return upb_MtDataEncoder_PutField(e, ptr, value_type, 2, value_mod);
}

char* upb_MtDataEncoder_EncodeMessageSet(upb_MtDataEncoder* e, char* ptr) {
  (void)upb_MtDataEncoder_GetInternal(e, ptr);
  return upb_MtDataEncoder_PutRaw(e, ptr, kUpb_EncodedVersion_MessageSetV1);
}

char* upb_MtDataEncoder_StartMessage(upb_MtDataEncoder* e, char* ptr,
                                     uint64_t msg_mod) {
  upb_MtDataEncoderInternal* in = upb_MtDataEncoder_GetInternal(e, ptr);
  in->state.msg_state.msg_modifiers = msg_mod;
  in->state.msg_state.last_field_num = 0;
  in->state.msg_state.oneof_state = kUpb_OneofState_NotStarted;

  ptr = upb_MtDataEncoder_PutRaw(e, ptr, kUpb_EncodedVersion_MessageV1);
  if (!ptr) return NULL;

  return upb_MtDataEncoder_PutModifier(e, ptr, msg_mod);
}

static char* _upb_MtDataEncoder_MaybePutFieldSkip(upb_MtDataEncoder* e,
                                                  char* ptr,
                                                  uint32_t field_num) {
  upb_MtDataEncoderInternal* in = (upb_MtDataEncoderInternal*)e->internal;
  if (field_num <= in->state.msg_state.last_field_num) return NULL;
  if (in->state.msg_state.last_field_num + 1 != field_num) {
    // Put skip.
    UPB_ASSERT(field_num > in->state.msg_state.last_field_num);
    uint32_t skip = field_num - in->state.msg_state.last_field_num;
    ptr = upb_MtDataEncoder_PutBase92Varint(
        e, ptr, skip, kUpb_EncodedValue_MinSkip, kUpb_EncodedValue_MaxSkip);
    if (!ptr) return NULL;
  }
  in->state.msg_state.last_field_num = field_num;
  return ptr;
}

static char* _upb_MtDataEncoder_PutFieldType(upb_MtDataEncoder* e, char* ptr,
                                             upb_FieldType type,
                                             uint64_t field_mod) {
  static const char kUpb_TypeToEncoded[] = {
      [kUpb_FieldType_Double] = kUpb_EncodedType_Double,
      [kUpb_FieldType_Float] = kUpb_EncodedType_Float,
      [kUpb_FieldType_Int64] = kUpb_EncodedType_Int64,
      [kUpb_FieldType_UInt64] = kUpb_EncodedType_UInt64,
      [kUpb_FieldType_Int32] = kUpb_EncodedType_Int32,
      [kUpb_FieldType_Fixed64] = kUpb_EncodedType_Fixed64,
      [kUpb_FieldType_Fixed32] = kUpb_EncodedType_Fixed32,
      [kUpb_FieldType_Bool] = kUpb_EncodedType_Bool,
      [kUpb_FieldType_String] = kUpb_EncodedType_String,
      [kUpb_FieldType_Group] = kUpb_EncodedType_Group,
      [kUpb_FieldType_Message] = kUpb_EncodedType_Message,
      [kUpb_FieldType_Bytes] = kUpb_EncodedType_Bytes,
      [kUpb_FieldType_UInt32] = kUpb_EncodedType_UInt32,
      [kUpb_FieldType_Enum] = kUpb_EncodedType_OpenEnum,
      [kUpb_FieldType_SFixed32] = kUpb_EncodedType_SFixed32,
      [kUpb_FieldType_SFixed64] = kUpb_EncodedType_SFixed64,
      [kUpb_FieldType_SInt32] = kUpb_EncodedType_SInt32,
      [kUpb_FieldType_SInt64] = kUpb_EncodedType_SInt64,
  };

  int encoded_type = kUpb_TypeToEncoded[type];

  if (field_mod & kUpb_FieldModifier_IsClosedEnum) {
    UPB_ASSERT(type == kUpb_FieldType_Enum);
    encoded_type = kUpb_EncodedType_ClosedEnum;
  }

  if (field_mod & kUpb_FieldModifier_IsRepeated) {
    // Repeated fields shift the type number up (unlike other modifiers which
    // are bit flags).
    encoded_type += kUpb_EncodedType_RepeatedBase;
  }

  return upb_MtDataEncoder_Put(e, ptr, encoded_type);
}

static char* _upb_MtDataEncoder_MaybePutModifiers(upb_MtDataEncoder* e,
                                                  char* ptr, upb_FieldType type,
                                                  uint64_t field_mod) {
  upb_MtDataEncoderInternal* in = (upb_MtDataEncoderInternal*)e->internal;
  uint32_t encoded_modifiers = 0;
  if ((field_mod & kUpb_FieldModifier_IsRepeated) &&
      upb_FieldType_IsPackable(type)) {
    bool field_is_packed = field_mod & kUpb_FieldModifier_IsPacked;
    bool default_is_packed = in->state.msg_state.msg_modifiers &
                             kUpb_MessageModifier_DefaultIsPacked;
    if (field_is_packed != default_is_packed) {
      encoded_modifiers |= kUpb_EncodedFieldModifier_FlipPacked;
    }
  }

  if (type == kUpb_FieldType_String) {
    bool field_validates_utf8 = field_mod & kUpb_FieldModifier_ValidateUtf8;
    bool message_validates_utf8 =
        in->state.msg_state.msg_modifiers & kUpb_MessageModifier_ValidateUtf8;
    if (field_validates_utf8 != message_validates_utf8) {
      // Old binaries do not recognize the field modifier.  We need the failure
      // mode to be too lax rather than too strict.  Our caller should have
      // handled this (see _upb_MessageDef_ValidateUtf8()).
      assert(!message_validates_utf8);
      encoded_modifiers |= kUpb_EncodedFieldModifier_FlipValidateUtf8;
    }
  }

  if (field_mod & kUpb_FieldModifier_IsProto3Singular) {
    encoded_modifiers |= kUpb_EncodedFieldModifier_IsProto3Singular;
  }

  if (field_mod & kUpb_FieldModifier_IsRequired) {
    encoded_modifiers |= kUpb_EncodedFieldModifier_IsRequired;
  }

  return upb_MtDataEncoder_PutModifier(e, ptr, encoded_modifiers);
}

char* upb_MtDataEncoder_PutField(upb_MtDataEncoder* e, char* ptr,
                                 upb_FieldType type, uint32_t field_num,
                                 uint64_t field_mod) {
  upb_MtDataEncoder_GetInternal(e, ptr);

  ptr = _upb_MtDataEncoder_MaybePutFieldSkip(e, ptr, field_num);
  if (!ptr) return NULL;

  ptr = _upb_MtDataEncoder_PutFieldType(e, ptr, type, field_mod);
  if (!ptr) return NULL;

  return _upb_MtDataEncoder_MaybePutModifiers(e, ptr, type, field_mod);
}

char* upb_MtDataEncoder_StartOneof(upb_MtDataEncoder* e, char* ptr) {
  upb_MtDataEncoderInternal* in = upb_MtDataEncoder_GetInternal(e, ptr);
  if (in->state.msg_state.oneof_state == kUpb_OneofState_NotStarted) {
    ptr = upb_MtDataEncoder_Put(e, ptr, _upb_FromBase92(kUpb_EncodedValue_End));
  } else {
    ptr = upb_MtDataEncoder_Put(
        e, ptr, _upb_FromBase92(kUpb_EncodedValue_OneofSeparator));
  }
  in->state.msg_state.oneof_state = kUpb_OneofState_StartedOneof;
  return ptr;
}

char* upb_MtDataEncoder_PutOneofField(upb_MtDataEncoder* e, char* ptr,
                                      uint32_t field_num) {
  upb_MtDataEncoderInternal* in = upb_MtDataEncoder_GetInternal(e, ptr);
  if (in->state.msg_state.oneof_state == kUpb_OneofState_EmittedOneofField) {
    ptr = upb_MtDataEncoder_Put(
        e, ptr, _upb_FromBase92(kUpb_EncodedValue_FieldSeparator));
    if (!ptr) return NULL;
  }
  ptr = upb_MtDataEncoder_PutBase92Varint(e, ptr, field_num, _upb_ToBase92(0),
                                          _upb_ToBase92(63));
  in->state.msg_state.oneof_state = kUpb_OneofState_EmittedOneofField;
  return ptr;
}

char* upb_MtDataEncoder_StartEnum(upb_MtDataEncoder* e, char* ptr) {
  upb_MtDataEncoderInternal* in = upb_MtDataEncoder_GetInternal(e, ptr);
  in->state.enum_state.present_values_mask = 0;
  in->state.enum_state.last_written_value = 0;

  return upb_MtDataEncoder_PutRaw(e, ptr, kUpb_EncodedVersion_EnumV1);
}

static char* upb_MtDataEncoder_FlushDenseEnumMask(upb_MtDataEncoder* e,
                                                  char* ptr) {
  upb_MtDataEncoderInternal* in = (upb_MtDataEncoderInternal*)e->internal;
  ptr = upb_MtDataEncoder_Put(e, ptr, in->state.enum_state.present_values_mask);
  in->state.enum_state.present_values_mask = 0;
  in->state.enum_state.last_written_value += 5;
  return ptr;
}

char* upb_MtDataEncoder_PutEnumValue(upb_MtDataEncoder* e, char* ptr,
                                     uint32_t val) {
  // TODO: optimize this encoding.
  upb_MtDataEncoderInternal* in = upb_MtDataEncoder_GetInternal(e, ptr);
  UPB_ASSERT(val >= in->state.enum_state.last_written_value);
  uint32_t delta = val - in->state.enum_state.last_written_value;
  if (delta >= 5 && in->state.enum_state.present_values_mask) {
    ptr = upb_MtDataEncoder_FlushDenseEnumMask(e, ptr);
    if (!ptr) {
      return NULL;
    }
    delta -= 5;
  }

  if (delta >= 5) {
    ptr = upb_MtDataEncoder_PutBase92Varint(
        e, ptr, delta, kUpb_EncodedValue_MinSkip, kUpb_EncodedValue_MaxSkip);
    in->state.enum_state.last_written_value += delta;
    delta = 0;
  }

  UPB_ASSERT((in->state.enum_state.present_values_mask >> delta) == 0);
  in->state.enum_state.present_values_mask |= 1ULL << delta;
  return ptr;
}

char* upb_MtDataEncoder_EndEnum(upb_MtDataEncoder* e, char* ptr) {
  upb_MtDataEncoderInternal* in = upb_MtDataEncoder_GetInternal(e, ptr);
  if (!in->state.enum_state.present_values_mask) return ptr;
  return upb_MtDataEncoder_FlushDenseEnumMask(e, ptr);
}


#include <stddef.h>
#include <stdint.h>
#include <string.h>


// Must be last.

struct upb_ExtensionRegistry {
  upb_exttable exts;
  upb_Arena* arena;
};

upb_ExtensionRegistry* upb_ExtensionRegistry_New(upb_Arena* arena) {
  upb_ExtensionRegistry* r = upb_Arena_Malloc(arena, sizeof(*r));
  if (!r) return NULL;
  r->arena = arena;
  if (!upb_exttable_init(&r->exts, 8, arena)) return NULL;
  return r;
}

UPB_API upb_ExtensionRegistryStatus upb_ExtensionRegistry_Add(
    upb_ExtensionRegistry* r, const upb_MiniTableExtension* e) {
  UPB_STATIC_ASSERT(
      offsetof(upb_MiniTableExtension,
               UPB_PRIVATE(field).UPB_PRIVATE(number)) == 0,
      "Extension must be first-member-of-struct convertable with uint32_t");
  uint32_t fieldnum = upb_MiniTableExtension_Number(e);
  const upb_MiniTable* extendee = upb_MiniTableExtension_Extendee(e);

  const uint32_t kMaxFieldNumber = (1 << 29) - 1;
  if (fieldnum == 0 ||
      (fieldnum > kMaxFieldNumber && !upb_MiniTable_IsMessageSet(extendee))) {
    return kUpb_ExtensionRegistryStatus_InvalidExtension;
  }

  if (upb_exttable_lookup(&r->exts, extendee, fieldnum) != NULL) {
    return kUpb_ExtensionRegistryStatus_DuplicateEntry;
  }

  if (!upb_exttable_insert(&r->exts, extendee, (const uint32_t*)e, r->arena)) {
    return kUpb_ExtensionRegistryStatus_OutOfMemory;
  }
  return kUpb_ExtensionRegistryStatus_Ok;
}

upb_ExtensionRegistryStatus upb_ExtensionRegistry_AddArray(
    upb_ExtensionRegistry* r, const upb_MiniTableExtension** e, size_t count) {
  const upb_MiniTableExtension** start = e;
  const upb_MiniTableExtension** end = UPB_PTRADD(e, count);
  upb_ExtensionRegistryStatus status = kUpb_ExtensionRegistryStatus_Ok;
  for (; e < end; e++) {
    status = upb_ExtensionRegistry_Add(r, *e);
    if (status != kUpb_ExtensionRegistryStatus_Ok) goto failure;
  }
  return kUpb_ExtensionRegistryStatus_Ok;

failure:
  // Back out the entries previously added.
  for (end = e, e = start; e < end; e++) {
    const upb_MiniTableExtension* ext = *e;
    upb_exttable_remove(&r->exts, upb_MiniTableExtension_Extendee(ext),
                        upb_MiniTableExtension_Number(ext));
  }
  UPB_ASSERT(status != kUpb_ExtensionRegistryStatus_Ok);
  return status;
}

const upb_MiniTableExtension* upb_ExtensionRegistry_Lookup(
    const upb_ExtensionRegistry* r, const upb_MiniTable* t, uint32_t num) {
  const uint32_t* v = upb_exttable_lookup(&r->exts, t, num);
  return (const upb_MiniTableExtension*)v;
}

size_t upb_ExtensionRegistry_Size(const upb_ExtensionRegistry* r) {
  return upb_exttable_size(&r->exts);
}


#include <stddef.h>
#include <stdint.h>


// Must be last.

#if UPB_TSAN
#include <sched.h>
#endif  // UPB_TSAN

const UPB_PRIVATE(upb_GeneratedExtensionListEntry) *
    UPB_PRIVATE(upb_generated_extension_list) = NULL;

typedef struct upb_GeneratedRegistry {
  UPB_ATOMIC(upb_GeneratedRegistryRef*) ref;
  UPB_ATOMIC(int32_t) ref_count;
} upb_GeneratedRegistry;

static upb_GeneratedRegistry* _upb_generated_registry(void) {
  static upb_GeneratedRegistry r = {NULL, 0};
  return &r;
}

static bool _upb_GeneratedRegistry_AddAllLinkedExtensions(
    upb_ExtensionRegistry* r) {
  const UPB_PRIVATE(upb_GeneratedExtensionListEntry)* entry =
      UPB_PRIVATE(upb_generated_extension_list);
  while (entry != NULL) {
    const upb_MiniTableExtension** current = entry->start;
    for (current = entry->start; current != entry->stop; ++current) {
      const upb_MiniTableExtension* ext = *current;
      // Sentinels and padding introduced by the linker can result in zeroed
      // entries, so simply skip them.
      if (*current == NULL) {
        // MSVC introduces padding that might not be sized exactly the same as
        // the linker array element, but it should be properly aligned, so just
        // skipping empty elements should be safe.  (If the size and align of
        // the array elements was different, we'd have to do something more
        // complicated).
        continue;
      }

      if (upb_ExtensionRegistry_Add(r, ext) !=
          kUpb_ExtensionRegistryStatus_Ok) {
        return false;
      }
    }
    entry = entry->next;
  }
  return true;
}

// Constructs a new GeneratedRegistryRef, adding all linked extensions to the
// registry or returning NULL on failure.
static upb_GeneratedRegistryRef* _upb_GeneratedRegistry_New(void) {
  upb_Arena* arena = NULL;
  upb_ExtensionRegistry* extreg = NULL;
  upb_GeneratedRegistryRef* ref = upb_gmalloc(sizeof(upb_GeneratedRegistryRef));
  if (ref == NULL) goto err;
  arena = upb_Arena_New();
  if (arena == NULL) goto err;
  extreg = upb_ExtensionRegistry_New(arena);
  if (extreg == NULL) goto err;

  ref->UPB_PRIVATE(arena) = arena;
  ref->UPB_PRIVATE(registry) = extreg;

  if (!_upb_GeneratedRegistry_AddAllLinkedExtensions(extreg)) goto err;

  return ref;

err:
  if (arena != NULL) upb_Arena_Free(arena);
  if (ref != NULL) upb_gfree(ref);
  return NULL;
}

const upb_GeneratedRegistryRef* upb_GeneratedRegistry_Load(void) {
  upb_GeneratedRegistry* registry = _upb_generated_registry();

  // Loop until we successfully acquire a reference.  This loop should only
  // kick in under extremely high contention, and it should be guaranteed to
  // succeed.
  while (true) {
    int32_t count = upb_Atomic_Load(&registry->ref_count, memory_order_acquire);

    // Try to increment the refcount, but only if it's not zero.
    while (count > 0) {
      if (upb_Atomic_CompareExchangeStrong(&registry->ref_count, &count,
                                           count + 1, memory_order_acquire,
                                           memory_order_relaxed)) {
        // Successfully incremented. We can now safely load and return the
        // pointer.
        const upb_GeneratedRegistryRef* ref =
            upb_Atomic_Load(&registry->ref, memory_order_acquire);
        UPB_ASSERT(ref != NULL);
        return ref;
      }
      // CAS failed, `count` was updated. Loop will retry.
    }

    // If we're here, the count was 0. Time for the slow path.
    // Double-check that the pointer is NULL before trying to create.
    upb_GeneratedRegistryRef* ref =
        upb_Atomic_Load(&registry->ref, memory_order_acquire);
    if (ref == NULL) {
      // Pointer is NULL, try to create and publish a new registry.
      upb_GeneratedRegistryRef* new_ref = _upb_GeneratedRegistry_New();
      if (new_ref == NULL) return NULL;  // OOM

      // Try to CAS the pointer from NULL to our new_ref.
      if (upb_Atomic_CompareExchangeStrong(&registry->ref, &ref, new_ref,
                                           memory_order_release,
                                           memory_order_acquire)) {
        // We won the race. Set the ref count to 1.
        upb_Atomic_Store(&registry->ref_count, 1, memory_order_release);
        return new_ref;
      } else {
        // We lost the race. `ref` now holds the pointer from the winning
        // thread. Clean up our unused one and loop to try again to get a
        // reference.
        upb_Arena_Free(new_ref->UPB_PRIVATE(arena));
        upb_gfree(new_ref);
      }
    }
    // If we are here, either we lost the CAS race, or the pointer was already
    // non-NULL. In either case, we loop to the top and try to increment the
    // refcount of the existing object.

#if UPB_TSAN
    // Yield to give other threads a chance to increment the refcount.  This is
    // especially an issue for TSAN builds, which are prone to locking up from
    // the thread with the upb_Atomic_Store call above getting starved.
    sched_yield();
#endif  // UPB_TSAN
  }
}

void upb_GeneratedRegistry_Release(const upb_GeneratedRegistryRef* r) {
  if (r == NULL) return;

  upb_GeneratedRegistry* registry = _upb_generated_registry();

  int ref_count = upb_Atomic_Sub(&registry->ref_count, 1, memory_order_acq_rel);
  UPB_ASSERT(registry->ref_count >= 0);

  // A ref_count of 1 means that we decremented the refcount to 0.
  if (ref_count == 1) {
    upb_GeneratedRegistryRef* ref =
        upb_Atomic_Exchange(&registry->ref, NULL, memory_order_acq_rel);
    if (ref != NULL) {
      // This is the last reference and we won any potential race to store NULL,
      // so we need to clean up.
      upb_Arena_Free(ref->UPB_PRIVATE(arena));
      upb_gfree(ref);
    }
  }
}

const upb_ExtensionRegistry* upb_GeneratedRegistry_Get(
    const upb_GeneratedRegistryRef* r) {
  if (r == NULL) return NULL;
  return r->UPB_PRIVATE(registry);
}


#include <stddef.h>
#include <stdint.h>


// Must be last.

const upb_MiniTableField* upb_MiniTable_GetOneof(const upb_MiniTable* m,
                                                 const upb_MiniTableField* f) {
  if (UPB_UNLIKELY(!upb_MiniTableField_IsInOneof(f))) {
    return NULL;
  }
  const upb_MiniTableField* ptr = &m->UPB_PRIVATE(fields)[0];
  const upb_MiniTableField* end =
      &m->UPB_PRIVATE(fields)[m->UPB_PRIVATE(field_count)];
  for (; ptr < end; ptr++) {
    if (ptr->presence == (*f).presence) {
      return ptr;
    }
  }
  return NULL;
}

bool upb_MiniTable_NextOneofField(const upb_MiniTable* m,
                                  const upb_MiniTableField** f) {
  const upb_MiniTableField* ptr = *f;
  const upb_MiniTableField* end =
      &m->UPB_PRIVATE(fields)[m->UPB_PRIVATE(field_count)];
  while (++ptr < end) {
    if (ptr->presence == (*f)->presence) {
      *f = ptr;
      return true;
    }
  }
  return false;
}


#include <stddef.h>


// Must be last.

// A MiniTable for a statically tree shaken message.  Messages that use this
// MiniTable are guaranteed to remain unlinked; unlike the empty message, this
// MiniTable is never replaced, which greatly simplifies everything, because the
// type of a sub-message is always known, without consulting a tagged bit.
const struct upb_MiniTable UPB_PRIVATE(_kUpb_MiniTable_StaticallyTreeShaken) = {
    .UPB_PRIVATE(fields) = NULL,
    .UPB_PRIVATE(size) = sizeof(struct upb_Message),
    .UPB_PRIVATE(field_count) = 0,
    .UPB_PRIVATE(ext) = kUpb_ExtMode_NonExtendable,
    .UPB_PRIVATE(dense_below) = 0,
    .UPB_PRIVATE(table_mask) = -1,
    .UPB_PRIVATE(required_count) = 0,
};


#include <assert.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>


// Must be last.

struct upb_DefPool {
  upb_Arena* arena;
  upb_strtable syms;   // full_name -> packed def ptr
  upb_strtable files;  // file_name -> (upb_FileDef*)
  upb_inttable exts;   // (upb_MiniTableExtension*) -> (upb_FieldDef*)
  upb_ExtensionRegistry* extreg;
  const upb_GeneratedRegistryRef* generated_extreg;
  const google_protobuf_FeatureSetDefaults* feature_set_defaults;
  upb_MiniTablePlatform platform;
  void* scratch_data;
  size_t scratch_size;
  size_t bytes_loaded;
  bool disable_closed_enum_checking;
  bool disable_implicit_field_presence;
};

void upb_DefPool_Free(upb_DefPool* s) {
  upb_GeneratedRegistry_Release(s->generated_extreg);
  upb_Arena_Free(s->arena);
  upb_gfree(s->scratch_data);
  upb_gfree(s);
}

static const char serialized_defaults[] = UPB_INTERNAL_UPB_EDITION_DEFAULTS;

upb_DefPool* upb_DefPool_New(void) {
  upb_DefPool* s = upb_gmalloc(sizeof(*s));
  if (!s) return NULL;

  s->arena = upb_Arena_New();
  s->bytes_loaded = 0;
  s->disable_closed_enum_checking = false;
  s->disable_implicit_field_presence = false;

  s->scratch_size = 240;
  s->scratch_data = upb_gmalloc(s->scratch_size);
  if (!s->scratch_data) goto err;

  if (!upb_strtable_init(&s->syms, 32, s->arena)) goto err;
  if (!upb_strtable_init(&s->files, 4, s->arena)) goto err;
  if (!upb_inttable_init(&s->exts, s->arena)) goto err;

  s->extreg = upb_ExtensionRegistry_New(s->arena);
  if (!s->extreg) goto err;

  s->generated_extreg = upb_GeneratedRegistry_Load();
  if (!s->generated_extreg) goto err;

  s->platform = kUpb_MiniTablePlatform_Native;

  upb_Status status;
  if (!upb_DefPool_SetFeatureSetDefaults(
          s, serialized_defaults, sizeof(serialized_defaults) - 1, &status)) {
    goto err;
  }

  if (!s->feature_set_defaults) goto err;

  return s;

err:
  upb_DefPool_Free(s);
  return NULL;
}

void upb_DefPool_DisableClosedEnumChecking(upb_DefPool* s) {
  UPB_ASSERT(upb_strtable_count(&s->files) == 0);
  s->disable_closed_enum_checking = true;
}

bool upb_DefPool_ClosedEnumCheckingDisabled(const upb_DefPool* s) {
  return s->disable_closed_enum_checking;
}

void upb_DefPool_DisableImplicitFieldPresence(upb_DefPool* s) {
  UPB_ASSERT(upb_strtable_count(&s->files) == 0);
  s->disable_implicit_field_presence = true;
}

bool upb_DefPool_ImplicitFieldPresenceDisabled(const upb_DefPool* s) {
  return s->disable_implicit_field_presence;
}

const google_protobuf_FeatureSetDefaults* upb_DefPool_FeatureSetDefaults(
    const upb_DefPool* s) {
  return s->feature_set_defaults;
}

bool upb_DefPool_SetFeatureSetDefaults(upb_DefPool* s,
                                       const char* serialized_defaults,
                                       size_t serialized_len,
                                       upb_Status* status) {
  const google_protobuf_FeatureSetDefaults* defaults = google_protobuf_FeatureSetDefaults_parse(
      serialized_defaults, serialized_len, s->arena);
  if (!defaults) {
    upb_Status_SetErrorFormat(status, "Failed to parse defaults");
    return false;
  }
  if (upb_strtable_count(&s->files) > 0) {
    upb_Status_SetErrorFormat(status,
                              "Feature set defaults can't be changed once the "
                              "pool has started building");
    return false;
  }
  int min_edition = google_protobuf_FeatureSetDefaults_minimum_edition(defaults);
  int max_edition = google_protobuf_FeatureSetDefaults_maximum_edition(defaults);
  if (min_edition > max_edition) {
    upb_Status_SetErrorFormat(status, "Invalid edition range %s to %s",
                              upb_FileDef_EditionName(min_edition),
                              upb_FileDef_EditionName(max_edition));
    return false;
  }
  size_t size;
  const google_protobuf_FeatureSetDefaults_FeatureSetEditionDefault* const*
      default_list = google_protobuf_FeatureSetDefaults_defaults(defaults, &size);
  int prev_edition = google_protobuf_EDITION_UNKNOWN;
  for (size_t i = 0; i < size; ++i) {
    int edition = google_protobuf_FeatureSetDefaults_FeatureSetEditionDefault_edition(
        default_list[i]);
    if (edition == google_protobuf_EDITION_UNKNOWN) {
      upb_Status_SetErrorFormat(status, "Invalid edition UNKNOWN specified");
      return false;
    }
    if (edition <= prev_edition) {
      upb_Status_SetErrorFormat(status,
                                "Feature set defaults are not strictly "
                                "increasing, %s is greater than or equal to %s",
                                upb_FileDef_EditionName(prev_edition),
                                upb_FileDef_EditionName(edition));
      return false;
    }
    prev_edition = edition;
  }

  // Copy the defaults into the pool.
  s->feature_set_defaults = defaults;
  return true;
}

bool _upb_DefPool_InsertExt(upb_DefPool* s, const upb_MiniTableExtension* ext,
                            const upb_FieldDef* f) {
  return upb_inttable_insert(&s->exts, (uintptr_t)ext, upb_value_constptr(f),
                             s->arena);
}

bool _upb_DefPool_InsertSym(upb_DefPool* s, upb_StringView sym, upb_value v,
                            upb_Status* status) {
  // TODO: table should support an operation "tryinsert" to avoid the double
  // lookup.
  if (upb_strtable_lookup2(&s->syms, sym.data, sym.size, NULL)) {
    upb_Status_SetErrorFormat(status, "duplicate symbol '%s'", sym.data);
    return false;
  }
  if (!upb_strtable_insert(&s->syms, sym.data, sym.size, v, s->arena)) {
    upb_Status_SetErrorMessage(status, "out of memory");
    return false;
  }
  return true;
}

static const void* _upb_DefPool_Unpack(const upb_DefPool* s, const char* sym,
                                       size_t size, upb_deftype_t type) {
  upb_value v;
  return upb_strtable_lookup2(&s->syms, sym, size, &v)
             ? _upb_DefType_Unpack(v, type)
             : NULL;
}

bool _upb_DefPool_LookupSym(const upb_DefPool* s, const char* sym, size_t size,
                            upb_value* v) {
  return upb_strtable_lookup2(&s->syms, sym, size, v);
}

upb_ExtensionRegistry* _upb_DefPool_ExtReg(const upb_DefPool* s) {
  return s->extreg;
}

void** _upb_DefPool_ScratchData(const upb_DefPool* s) {
  return (void**)&s->scratch_data;
}

size_t* _upb_DefPool_ScratchSize(const upb_DefPool* s) {
  return (size_t*)&s->scratch_size;
}

void _upb_DefPool_SetPlatform(upb_DefPool* s, upb_MiniTablePlatform platform) {
  assert(upb_strtable_count(&s->files) == 0);
  s->platform = platform;
}

const upb_MessageDef* upb_DefPool_FindMessageByName(const upb_DefPool* s,
                                                    const char* sym) {
  return upb_DefPool_FindMessageByNameWithSize(s, sym, strlen(sym));
}

const upb_MessageDef* upb_DefPool_FindMessageByNameWithSize(
    const upb_DefPool* s, const char* sym, size_t len) {
  return _upb_DefPool_Unpack(s, sym, len, UPB_DEFTYPE_MSG);
}

const upb_EnumDef* upb_DefPool_FindEnumByName(const upb_DefPool* s,
                                              const char* sym) {
  return upb_DefPool_FindEnumByNameWithSize(s, sym, strlen(sym));
}

const upb_EnumDef* upb_DefPool_FindEnumByNameWithSize(const upb_DefPool* s,
                                                      const char* sym,
                                                      size_t len) {
  return _upb_DefPool_Unpack(s, sym, len, UPB_DEFTYPE_ENUM);
}

const upb_EnumValueDef* upb_DefPool_FindEnumValueByName(const upb_DefPool* s,
                                                        const char* sym) {
  return upb_DefPool_FindEnumValueByNameWithSize(s, sym, strlen(sym));
}

const upb_EnumValueDef* upb_DefPool_FindEnumValueByNameWithSize(
    const upb_DefPool* s, const char* sym, size_t len) {
  return _upb_DefPool_Unpack(s, sym, len, UPB_DEFTYPE_ENUMVAL);
}

const upb_FileDef* upb_DefPool_FindFileByName(const upb_DefPool* s,
                                              const char* name) {
  upb_value v;
  return upb_strtable_lookup(&s->files, name, &v) ? upb_value_getconstptr(v)
                                                  : NULL;
}

const upb_FileDef* upb_DefPool_FindFileByNameWithSize(const upb_DefPool* s,
                                                      const char* name,
                                                      size_t len) {
  upb_value v;
  return upb_strtable_lookup2(&s->files, name, len, &v)
             ? upb_value_getconstptr(v)
             : NULL;
}

const upb_FieldDef* upb_DefPool_FindExtensionByNameWithSize(
    const upb_DefPool* s, const char* name, size_t size) {
  upb_value v;
  if (!upb_strtable_lookup2(&s->syms, name, size, &v)) return NULL;

  switch (_upb_DefType_Type(v)) {
    case UPB_DEFTYPE_FIELD:
      return _upb_DefType_Unpack(v, UPB_DEFTYPE_FIELD);
    case UPB_DEFTYPE_MSG: {
      const upb_MessageDef* m = _upb_DefType_Unpack(v, UPB_DEFTYPE_MSG);
      if (_upb_MessageDef_InMessageSet(m)) {
        for (int i = 0; i < upb_MessageDef_NestedExtensionCount(m); i++) {
          const upb_FieldDef* ext = upb_MessageDef_NestedExtension(m, i);
          if (upb_FieldDef_MessageSubDef(ext) == m) {
            return ext;
          }
        }
      }
      return NULL;
    }
    default:
      break;
  }

  return NULL;
}

const upb_FieldDef* upb_DefPool_FindExtensionByName(const upb_DefPool* s,
                                                    const char* sym) {
  return upb_DefPool_FindExtensionByNameWithSize(s, sym, strlen(sym));
}

const upb_ServiceDef* upb_DefPool_FindServiceByName(const upb_DefPool* s,
                                                    const char* name) {
  return _upb_DefPool_Unpack(s, name, strlen(name), UPB_DEFTYPE_SERVICE);
}

const upb_ServiceDef* upb_DefPool_FindServiceByNameWithSize(
    const upb_DefPool* s, const char* name, size_t size) {
  return _upb_DefPool_Unpack(s, name, size, UPB_DEFTYPE_SERVICE);
}

const upb_FileDef* upb_DefPool_FindFileContainingSymbol(const upb_DefPool* s,
                                                        const char* name) {
  upb_value v;
  // TODO: non-extension fields and oneofs.
  if (upb_strtable_lookup(&s->syms, name, &v)) {
    switch (_upb_DefType_Type(v)) {
      case UPB_DEFTYPE_EXT: {
        const upb_FieldDef* f = _upb_DefType_Unpack(v, UPB_DEFTYPE_EXT);
        return upb_FieldDef_File(f);
      }
      case UPB_DEFTYPE_MSG: {
        const upb_MessageDef* m = _upb_DefType_Unpack(v, UPB_DEFTYPE_MSG);
        return upb_MessageDef_File(m);
      }
      case UPB_DEFTYPE_ENUM: {
        const upb_EnumDef* e = _upb_DefType_Unpack(v, UPB_DEFTYPE_ENUM);
        return upb_EnumDef_File(e);
      }
      case UPB_DEFTYPE_ENUMVAL: {
        const upb_EnumValueDef* ev =
            _upb_DefType_Unpack(v, UPB_DEFTYPE_ENUMVAL);
        return upb_EnumDef_File(upb_EnumValueDef_Enum(ev));
      }
      case UPB_DEFTYPE_SERVICE: {
        const upb_ServiceDef* service =
            _upb_DefType_Unpack(v, UPB_DEFTYPE_SERVICE);
        return upb_ServiceDef_File(service);
      }
      default:
        UPB_UNREACHABLE();
    }
  }

  const char* last_dot = strrchr(name, '.');
  if (last_dot) {
    const upb_MessageDef* parent =
        upb_DefPool_FindMessageByNameWithSize(s, name, last_dot - name);
    if (parent) {
      const char* shortname = last_dot + 1;
      if (upb_MessageDef_FindByNameWithSize(parent, shortname,
                                            strlen(shortname), NULL, NULL)) {
        return upb_MessageDef_File(parent);
      }
    }
  }

  return NULL;
}

static void remove_filedef(upb_DefPool* s, upb_FileDef* file) {
  intptr_t iter = UPB_INTTABLE_BEGIN;
  upb_StringView key;
  upb_value val;
  while (upb_strtable_next2(&s->syms, &key, &val, &iter)) {
    const upb_FileDef* f;
    switch (_upb_DefType_Type(val)) {
      case UPB_DEFTYPE_EXT:
        f = upb_FieldDef_File(_upb_DefType_Unpack(val, UPB_DEFTYPE_EXT));
        break;
      case UPB_DEFTYPE_MSG:
        f = upb_MessageDef_File(_upb_DefType_Unpack(val, UPB_DEFTYPE_MSG));
        break;
      case UPB_DEFTYPE_ENUM:
        f = upb_EnumDef_File(_upb_DefType_Unpack(val, UPB_DEFTYPE_ENUM));
        break;
      case UPB_DEFTYPE_ENUMVAL:
        f = upb_EnumDef_File(upb_EnumValueDef_Enum(
            _upb_DefType_Unpack(val, UPB_DEFTYPE_ENUMVAL)));
        break;
      case UPB_DEFTYPE_SERVICE:
        f = upb_ServiceDef_File(_upb_DefType_Unpack(val, UPB_DEFTYPE_SERVICE));
        break;
      default:
        UPB_UNREACHABLE();
    }

    if (f == file) upb_strtable_removeiter(&s->syms, &iter);
  }
}

static const upb_FileDef* upb_DefBuilder_AddFileToPool(
    upb_DefBuilder* const builder, upb_DefPool* const s,
    const google_protobuf_FileDescriptorProto* const file_proto,
    const upb_StringView name, upb_Status* const status) {
  if (UPB_SETJMP(builder->err) != 0) {
    UPB_ASSERT(!upb_Status_IsOk(status));
    if (builder->file) {
      remove_filedef(s, builder->file);
      builder->file = NULL;
    }
  } else if (!builder->arena || !builder->tmp_arena ||
             !upb_strtable_init(&builder->feature_cache, 16,
                                builder->tmp_arena) ||
             !(builder->legacy_features =
                   google_protobuf_FeatureSet_new(builder->tmp_arena))) {
    _upb_DefBuilder_OomErr(builder);
  } else {
    _upb_FileDef_Create(builder, file_proto);
    upb_strtable_insert(&s->files, name.data, name.size,
                        upb_value_constptr(builder->file), builder->arena);
    UPB_ASSERT(upb_Status_IsOk(status));
    upb_Arena_Fuse(s->arena, builder->arena);
  }

  if (builder->arena) upb_Arena_Free(builder->arena);
  if (builder->tmp_arena) upb_Arena_Free(builder->tmp_arena);
  return builder->file;
}

static const upb_FileDef* _upb_DefPool_AddFile(
    upb_DefPool* s, const google_protobuf_FileDescriptorProto* file_proto,
    const upb_MiniTableFile* layout, upb_Status* status) {
  const upb_StringView name = google_protobuf_FileDescriptorProto_name(file_proto);

  // Determine whether we already know about this file.
  {
    upb_value v;
    if (upb_strtable_lookup2(&s->files, name.data, name.size, &v)) {
      upb_Status_SetErrorFormat(status,
                                "duplicate file name " UPB_STRINGVIEW_FORMAT,
                                UPB_STRINGVIEW_ARGS(name));
      return NULL;
    }
  }

  upb_DefBuilder ctx = {
      .symtab = s,
      .tmp_buf = NULL,
      .tmp_buf_size = 0,
      .layout = layout,
      .platform = s->platform,
      .msg_count = 0,
      .enum_count = 0,
      .ext_count = 0,
      .status = status,
      .file = NULL,
      .arena = upb_Arena_New(),
      .tmp_arena = upb_Arena_New(),
  };

  return upb_DefBuilder_AddFileToPool(&ctx, s, file_proto, name, status);
}

const upb_FileDef* upb_DefPool_AddFile(
    upb_DefPool* s, const google_protobuf_FileDescriptorProto* file_proto,
    upb_Status* status) {
  return _upb_DefPool_AddFile(s, file_proto, NULL, status);
}

bool _upb_DefPool_LoadDefInitEx(upb_DefPool* s, const _upb_DefPool_Init* init,
                                bool rebuild_minitable) {
  /* Since this function should never fail (it would indicate a bug in upb) we
   * print errors to stderr instead of returning error status to the user. */
  _upb_DefPool_Init** deps = init->deps;
  google_protobuf_FileDescriptorProto* file;
  upb_Arena* arena;
  upb_Status status;

  upb_Status_Clear(&status);

  if (upb_DefPool_FindFileByName(s, init->filename)) {
    return true;
  }

  arena = upb_Arena_New();

  for (; *deps; deps++) {
    if (!_upb_DefPool_LoadDefInitEx(s, *deps, rebuild_minitable)) goto err;
  }

  file = google_protobuf_FileDescriptorProto_parse_ex(
      init->descriptor.data, init->descriptor.size, NULL,
      kUpb_DecodeOption_AliasString, arena);
  s->bytes_loaded += init->descriptor.size;

  if (!file) {
    upb_Status_SetErrorFormat(
        &status,
        "Failed to parse compiled-in descriptor for file '%s'. This should "
        "never happen.",
        init->filename);
    goto err;
  }

  const upb_MiniTableFile* mt = rebuild_minitable ? NULL : init->layout;
  if (!_upb_DefPool_AddFile(s, file, mt, &status)) {
    goto err;
  }

  upb_Arena_Free(arena);
  return true;

err:
  fprintf(stderr,
          "Error loading compiled-in descriptor for file '%s' (this should "
          "never happen): %s\n",
          init->filename, upb_Status_ErrorMessage(&status));
  upb_Arena_Free(arena);
  return false;
}

size_t _upb_DefPool_BytesLoaded(const upb_DefPool* s) {
  return s->bytes_loaded;
}

upb_Arena* _upb_DefPool_Arena(const upb_DefPool* s) { return s->arena; }

const upb_FieldDef* upb_DefPool_FindExtensionByMiniTable(
    const upb_DefPool* s, const upb_MiniTableExtension* ext) {
  upb_value v;
  bool ok = upb_inttable_lookup(&s->exts, (uintptr_t)ext, &v);
  UPB_ASSERT(ok);
  return upb_value_getconstptr(v);
}

const upb_FieldDef* upb_DefPool_FindExtensionByNumber(const upb_DefPool* s,
                                                      const upb_MessageDef* m,
                                                      int32_t fieldnum) {
  const upb_MiniTable* t = upb_MessageDef_MiniTable(m);
  const upb_MiniTableExtension* ext =
      upb_ExtensionRegistry_Lookup(s->extreg, t, fieldnum);
  return ext ? upb_DefPool_FindExtensionByMiniTable(s, ext) : NULL;
}

const upb_ExtensionRegistry* upb_DefPool_ExtensionRegistry(
    const upb_DefPool* s) {
  return s->extreg;
}

const upb_FieldDef** upb_DefPool_GetAllExtensions(const upb_DefPool* s,
                                                  const upb_MessageDef* m,
                                                  size_t* count) {
  size_t n = 0;
  intptr_t iter = UPB_INTTABLE_BEGIN;
  uintptr_t key;
  upb_value val;
  // This is O(all exts) instead of O(exts for m).  If we need this to be
  // efficient we may need to make extreg into a two-level table, or have a
  // second per-message index.
  while (upb_inttable_next(&s->exts, &key, &val, &iter)) {
    const upb_FieldDef* f = upb_value_getconstptr(val);
    if (upb_FieldDef_ContainingType(f) == m) n++;
  }
  const upb_FieldDef** exts = upb_gmalloc(n * sizeof(*exts));
  iter = UPB_INTTABLE_BEGIN;
  size_t i = 0;
  while (upb_inttable_next(&s->exts, &key, &val, &iter)) {
    const upb_FieldDef* f = upb_value_getconstptr(val);
    if (upb_FieldDef_ContainingType(f) == m) exts[i++] = f;
  }
  *count = n;
  return exts;
}

bool _upb_DefPool_LoadDefInit(upb_DefPool* s, const _upb_DefPool_Init* init) {
  return _upb_DefPool_LoadDefInitEx(s, init, false);
}

const upb_ExtensionRegistry* _upb_DefPool_GeneratedExtensionRegistry(
    const upb_DefPool* s) {
  return upb_GeneratedRegistry_Get(s->generated_extreg);
}


// Must be last.

upb_deftype_t _upb_DefType_Type(upb_value v) {
  const uintptr_t num = (uintptr_t)upb_value_getconstptr(v);
  return num & UPB_DEFTYPE_MASK;
}

upb_value _upb_DefType_Pack(const void* ptr, upb_deftype_t type) {
  uintptr_t num = (uintptr_t)ptr;
  UPB_ASSERT((num & UPB_DEFTYPE_MASK) == 0);
  num |= type;
  return upb_value_constptr((const void*)num);
}

const void* _upb_DefType_Unpack(upb_value v, upb_deftype_t type) {
  uintptr_t num = (uintptr_t)upb_value_getconstptr(v);
  return (num & UPB_DEFTYPE_MASK) == type
             ? (const void*)(num & ~UPB_DEFTYPE_MASK)
             : NULL;
}


// Must be last.

bool _upb_DescState_Grow(upb_DescState* d, upb_Arena* a) {
  const size_t oldbufsize = d->bufsize;
  const int used = d->ptr - d->buf;

  if (!d->buf) {
    d->buf = upb_Arena_Malloc(a, d->bufsize);
    if (!d->buf) return false;
    d->ptr = d->buf;
    d->e.end = d->buf + d->bufsize;
  }

  if (oldbufsize - used < kUpb_MtDataEncoder_MinSize) {
    d->bufsize *= 2;
    d->buf = upb_Arena_Realloc(a, d->buf, oldbufsize, d->bufsize);
    if (!d->buf) return false;
    d->ptr = d->buf + used;
    d->e.end = d->buf + d->bufsize;
  }

  return true;
}


#include <stddef.h>
#include <stdint.h>
#include <string.h>


// Must be last.

struct upb_EnumDef {
  UPB_ALIGN_AS(8) const google_protobuf_EnumOptions* opts;
  const google_protobuf_FeatureSet* resolved_features;
  const upb_MiniTableEnum* layout;  // Only for proto2.
  const upb_FileDef* file;
  const upb_MessageDef* containing_type;  // Could be merged with "file".
  const char* full_name;
  upb_strtable ntoi;
  upb_inttable iton;
  const upb_EnumValueDef* values;
  const upb_EnumReservedRange* res_ranges;
  const upb_StringView* res_names;
  int value_count;
  int res_range_count;
  int res_name_count;
  int32_t defaultval;
  google_protobuf_SymbolVisibility visibility;
  bool is_sorted;  // Whether all of the values are defined in ascending order.
};

upb_EnumDef* _upb_EnumDef_At(const upb_EnumDef* e, int i) {
  return (upb_EnumDef*)&e[i];
}

const upb_MiniTableEnum* _upb_EnumDef_MiniTable(const upb_EnumDef* e) {
  return e->layout;
}

bool _upb_EnumDef_Insert(upb_EnumDef* e, upb_EnumValueDef* v, upb_Arena* a) {
  const char* name = upb_EnumValueDef_Name(v);
  const upb_value val = upb_value_constptr(v);
  bool ok = upb_strtable_insert(&e->ntoi, name, strlen(name), val, a);
  if (!ok) return false;

  // Multiple enumerators can have the same number, first one wins.
  const int number = upb_EnumValueDef_Number(v);
  if (!upb_inttable_lookup(&e->iton, number, NULL)) {
    return upb_inttable_insert(&e->iton, number, val, a);
  }
  return true;
}

const google_protobuf_EnumOptions* upb_EnumDef_Options(const upb_EnumDef* e) {
  return e->opts;
}

bool upb_EnumDef_HasOptions(const upb_EnumDef* e) {
  return e->opts != (void*)kUpbDefOptDefault;
}

const google_protobuf_FeatureSet* upb_EnumDef_ResolvedFeatures(const upb_EnumDef* e) {
  return e->resolved_features;
}

google_protobuf_SymbolVisibility upb_EnumDef_Visibility(const upb_EnumDef* e) {
  return e->visibility;
}

const char* upb_EnumDef_FullName(const upb_EnumDef* e) { return e->full_name; }

const char* upb_EnumDef_Name(const upb_EnumDef* e) {
  return _upb_DefBuilder_FullToShort(e->full_name);
}

const upb_FileDef* upb_EnumDef_File(const upb_EnumDef* e) { return e->file; }

const upb_MessageDef* upb_EnumDef_ContainingType(const upb_EnumDef* e) {
  return e->containing_type;
}

int32_t upb_EnumDef_Default(const upb_EnumDef* e) {
  UPB_ASSERT(upb_EnumDef_FindValueByNumber(e, e->defaultval));
  return e->defaultval;
}

int upb_EnumDef_ReservedRangeCount(const upb_EnumDef* e) {
  return e->res_range_count;
}

const upb_EnumReservedRange* upb_EnumDef_ReservedRange(const upb_EnumDef* e,
                                                       int i) {
  UPB_ASSERT(0 <= i && i < e->res_range_count);
  return _upb_EnumReservedRange_At(e->res_ranges, i);
}

int upb_EnumDef_ReservedNameCount(const upb_EnumDef* e) {
  return e->res_name_count;
}

upb_StringView upb_EnumDef_ReservedName(const upb_EnumDef* e, int i) {
  UPB_ASSERT(0 <= i && i < e->res_name_count);
  return e->res_names[i];
}

int upb_EnumDef_ValueCount(const upb_EnumDef* e) { return e->value_count; }

const upb_EnumValueDef* upb_EnumDef_FindValueByName(const upb_EnumDef* e,
                                                    const char* name) {
  return upb_EnumDef_FindValueByNameWithSize(e, name, strlen(name));
}

const upb_EnumValueDef* upb_EnumDef_FindValueByNameWithSize(
    const upb_EnumDef* e, const char* name, size_t size) {
  upb_value v;
  return upb_strtable_lookup2(&e->ntoi, name, size, &v)
             ? upb_value_getconstptr(v)
             : NULL;
}

const upb_EnumValueDef* upb_EnumDef_FindValueByNumber(const upb_EnumDef* e,
                                                      int32_t num) {
  upb_value v;
  return upb_inttable_lookup(&e->iton, num, &v) ? upb_value_getconstptr(v)
                                                : NULL;
}

bool upb_EnumDef_CheckNumber(const upb_EnumDef* e, int32_t num) {
  // We could use upb_EnumDef_FindValueByNumber(e, num) != NULL, but we expect
  // this to be faster (especially for small numbers).
  return upb_MiniTableEnum_CheckValue(e->layout, num);
}

const upb_EnumValueDef* upb_EnumDef_Value(const upb_EnumDef* e, int i) {
  UPB_ASSERT(0 <= i && i < e->value_count);
  return _upb_EnumValueDef_At(e->values, i);
}

static bool upb_EnumDef_IsSpecifiedAsClosed(const upb_EnumDef* e) {
  return google_protobuf_FeatureSet_enum_type(e->resolved_features) ==
         google_protobuf_FeatureSet_CLOSED;
}

bool upb_EnumDef_IsClosed(const upb_EnumDef* e) {
  if (_upb_FileDef_ClosedEnumCheckingDisabled(e->file)) return false;
  return upb_EnumDef_IsSpecifiedAsClosed(e);
}

bool upb_EnumDef_MiniDescriptorEncode(const upb_EnumDef* e, upb_Arena* a,
                                      upb_StringView* out) {
  upb_DescState s;
  _upb_DescState_Init(&s);

  const upb_EnumValueDef** sorted = NULL;
  if (!e->is_sorted) {
    sorted = _upb_EnumValueDefs_Sorted(e->values, e->value_count, a);
    if (!sorted) return false;
  }

  if (!_upb_DescState_Grow(&s, a)) return false;
  s.ptr = upb_MtDataEncoder_StartEnum(&s.e, s.ptr);

  // Duplicate values are allowed but we only encode each value once.
  uint32_t previous = 0;

  for (int i = 0; i < e->value_count; i++) {
    const uint32_t current =
        upb_EnumValueDef_Number(sorted ? sorted[i] : upb_EnumDef_Value(e, i));
    if (i != 0 && previous == current) continue;

    if (!_upb_DescState_Grow(&s, a)) return false;
    s.ptr = upb_MtDataEncoder_PutEnumValue(&s.e, s.ptr, current);
    previous = current;
  }

  if (!_upb_DescState_Grow(&s, a)) return false;
  s.ptr = upb_MtDataEncoder_EndEnum(&s.e, s.ptr);

  // There will always be room for this '\0' in the encoder buffer because
  // kUpb_MtDataEncoder_MinSize is overkill for upb_MtDataEncoder_EndEnum().
  UPB_ASSERT(s.ptr < s.buf + s.bufsize);
  *s.ptr = '\0';

  out->data = s.buf;
  out->size = s.ptr - s.buf;
  return true;
}

static upb_MiniTableEnum* create_enumlayout(upb_DefBuilder* ctx,
                                            const upb_EnumDef* e) {
  upb_StringView sv;
  bool ok = upb_EnumDef_MiniDescriptorEncode(e, ctx->tmp_arena, &sv);
  if (!ok) _upb_DefBuilder_Errf(ctx, "OOM while building enum MiniDescriptor");

  upb_Status status;
  upb_MiniTableEnum* layout =
      upb_MiniTableEnum_Build(sv.data, sv.size, ctx->arena, &status);
  if (!layout)
    _upb_DefBuilder_Errf(ctx, "Error building enum MiniTable: %s", status.msg);
  return layout;
}

static upb_StringView* _upb_EnumReservedNames_New(
    upb_DefBuilder* ctx, int n, const upb_StringView* protos) {
  upb_StringView* sv = UPB_DEFBUILDER_ALLOCARRAY(ctx, upb_StringView, n);
  for (int i = 0; i < n; i++) {
    sv[i].data =
        upb_strdup2(protos[i].data, protos[i].size, _upb_DefBuilder_Arena(ctx));
    sv[i].size = protos[i].size;
  }
  return sv;
}

static void create_enumdef(upb_DefBuilder* ctx, const char* prefix,
                           const google_protobuf_EnumDescriptorProto* enum_proto,
                           const google_protobuf_FeatureSet* parent_features,
                           upb_EnumDef* e) {
  const google_protobuf_EnumValueDescriptorProto* const* values;
  const google_protobuf_EnumDescriptorProto_EnumReservedRange* const* res_ranges;
  const upb_StringView* res_names;
  upb_StringView name;
  size_t n_value, n_res_range, n_res_name;

  UPB_DEF_SET_OPTIONS(e->opts, EnumDescriptorProto, EnumOptions, enum_proto);
  e->resolved_features = _upb_DefBuilder_ResolveFeatures(
      ctx, parent_features, google_protobuf_EnumOptions_features(e->opts));

  // Must happen before _upb_DefBuilder_Add()
  e->file = _upb_DefBuilder_File(ctx);

  name = google_protobuf_EnumDescriptorProto_name(enum_proto);

  e->full_name = _upb_DefBuilder_MakeFullName(ctx, prefix, name);
  _upb_DefBuilder_Add(ctx, e->full_name,
                      _upb_DefType_Pack(e, UPB_DEFTYPE_ENUM));

  values = google_protobuf_EnumDescriptorProto_value(enum_proto, &n_value);

  if (n_value == 0) {
    _upb_DefBuilder_Errf(ctx, "enums must contain at least one value (%s)",
                         e->full_name);
  }

  e->defaultval = google_protobuf_EnumValueDescriptorProto_number(values[0]);

  // When the special UPB_TREAT_CLOSED_ENUMS_LIKE_OPEN is enabled, we have to
  // exempt closed enums from this check, even when we are treating them as
  // open.
  //
  // We rely on the fact that the proto compiler will have already ensured that
  // implicit presence fields do not use closed enums, even if we are treating
  // them as open.
  if (!upb_EnumDef_IsSpecifiedAsClosed(e) && e->defaultval != 0) {
    _upb_DefBuilder_Errf(ctx,
                         "for open enums, the first value must be zero (%s)",
                         upb_EnumDef_FullName(e));
  }

  bool ok = upb_strtable_init(&e->ntoi, n_value, ctx->arena);
  if (!ok) _upb_DefBuilder_OomErr(ctx);

  ok = upb_inttable_init(&e->iton, ctx->arena);
  if (!ok) _upb_DefBuilder_OomErr(ctx);

  e->value_count = n_value;
  e->values = _upb_EnumValueDefs_New(ctx, prefix, n_value, values,
                                     e->resolved_features, e, &e->is_sorted);

  res_ranges =
      google_protobuf_EnumDescriptorProto_reserved_range(enum_proto, &n_res_range);
  e->res_range_count = n_res_range;
  e->res_ranges = _upb_EnumReservedRanges_New(ctx, n_res_range, res_ranges, e);

  res_names = google_protobuf_EnumDescriptorProto_reserved_name(enum_proto, &n_res_name);
  e->res_name_count = n_res_name;
  e->res_names = _upb_EnumReservedNames_New(ctx, n_res_name, res_names);

  e->visibility = google_protobuf_EnumDescriptorProto_visibility(enum_proto);

  if (!upb_inttable_compact(&e->iton, ctx->arena)) _upb_DefBuilder_OomErr(ctx);

  if (upb_EnumDef_IsClosed(e)) {
    if (ctx->layout) {
      e->layout = upb_MiniTableFile_Enum(ctx->layout, ctx->enum_count++);
    } else {
      e->layout = create_enumlayout(ctx, e);
    }
  } else {
    e->layout = NULL;
  }
}

upb_EnumDef* _upb_EnumDefs_New(upb_DefBuilder* ctx, int n,
                               const google_protobuf_EnumDescriptorProto* const* protos,
                               const google_protobuf_FeatureSet* parent_features,
                               const upb_MessageDef* containing_type) {
  _upb_DefType_CheckPadding(sizeof(upb_EnumDef));

  // If a containing type is defined then get the full name from that.
  // Otherwise use the package name from the file def.
  const char* name = containing_type ? upb_MessageDef_FullName(containing_type)
                                     : _upb_FileDef_RawPackage(ctx->file);

  upb_EnumDef* e = UPB_DEFBUILDER_ALLOCARRAY(ctx, upb_EnumDef, n);
  for (int i = 0; i < n; i++) {
    create_enumdef(ctx, name, protos[i], parent_features, &e[i]);
    e[i].containing_type = containing_type;
  }
  return e;
}


#include <stdint.h>


// Must be last.

struct upb_EnumReservedRange {
  int32_t start;
  int32_t end;
};

upb_EnumReservedRange* _upb_EnumReservedRange_At(const upb_EnumReservedRange* r,
                                                 int i) {
  return (upb_EnumReservedRange*)&r[i];
}

int32_t upb_EnumReservedRange_Start(const upb_EnumReservedRange* r) {
  return r->start;
}
int32_t upb_EnumReservedRange_End(const upb_EnumReservedRange* r) {
  return r->end;
}

upb_EnumReservedRange* _upb_EnumReservedRanges_New(
    upb_DefBuilder* ctx, int n,
    const google_protobuf_EnumDescriptorProto_EnumReservedRange* const* protos,
    const upb_EnumDef* e) {
  upb_EnumReservedRange* r =
      UPB_DEFBUILDER_ALLOCARRAY(ctx, upb_EnumReservedRange, n);

  for (int i = 0; i < n; i++) {
    const int32_t start =
        google_protobuf_EnumDescriptorProto_EnumReservedRange_start(protos[i]);
    const int32_t end =
        google_protobuf_EnumDescriptorProto_EnumReservedRange_end(protos[i]);

    // A full validation would also check that each range is disjoint, and that
    // none of the fields overlap with the extension ranges, but we are just
    // sanity checking here.

    // Note: Not a typo! Unlike extension ranges and message reserved ranges,
    // the end value of an enum reserved range is *inclusive*!
    if (end < start) {
      _upb_DefBuilder_Errf(ctx, "Reserved range (%d, %d) is invalid, enum=%s\n",
                           (int)start, (int)end, upb_EnumDef_FullName(e));
    }

    r[i].start = start;
    r[i].end = end;
  }

  return r;
}


#include <stddef.h>
#include <stdint.h>
#include <stdlib.h>


// Must be last.

struct upb_EnumValueDef {
  UPB_ALIGN_AS(8) const google_protobuf_EnumValueOptions* opts;
  const google_protobuf_FeatureSet* resolved_features;
  const upb_EnumDef* parent;
  const char* full_name;
  int32_t number;
};

upb_EnumValueDef* _upb_EnumValueDef_At(const upb_EnumValueDef* v, int i) {
  return (upb_EnumValueDef*)&v[i];
}

static int _upb_EnumValueDef_Compare(const void* p1, const void* p2) {
  const uint32_t v1 = (*(const upb_EnumValueDef**)p1)->number;
  const uint32_t v2 = (*(const upb_EnumValueDef**)p2)->number;
  return (v1 < v2) ? -1 : (v1 > v2);
}

const upb_EnumValueDef** _upb_EnumValueDefs_Sorted(const upb_EnumValueDef* v,
                                                   size_t n, upb_Arena* a) {
  if (SIZE_MAX / sizeof(void*) < n) return NULL;
  // TODO: Try to replace this arena alloc with a persistent scratch buffer.
  upb_EnumValueDef** out =
      (upb_EnumValueDef**)upb_Arena_Malloc(a, n * sizeof(void*));
  if (!out) return NULL;

  for (int i = 0; i < n; i++) {
    out[i] = (upb_EnumValueDef*)&v[i];
  }
  qsort(out, n, sizeof(void*), _upb_EnumValueDef_Compare);

  return (const upb_EnumValueDef**)out;
}

const google_protobuf_EnumValueOptions* upb_EnumValueDef_Options(
    const upb_EnumValueDef* v) {
  return v->opts;
}

bool upb_EnumValueDef_HasOptions(const upb_EnumValueDef* v) {
  return v->opts != (void*)kUpbDefOptDefault;
}

const google_protobuf_FeatureSet* upb_EnumValueDef_ResolvedFeatures(
    const upb_EnumValueDef* e) {
  return e->resolved_features;
}

const upb_EnumDef* upb_EnumValueDef_Enum(const upb_EnumValueDef* v) {
  return v->parent;
}

const char* upb_EnumValueDef_FullName(const upb_EnumValueDef* v) {
  return v->full_name;
}

const char* upb_EnumValueDef_Name(const upb_EnumValueDef* v) {
  return _upb_DefBuilder_FullToShort(v->full_name);
}

int32_t upb_EnumValueDef_Number(const upb_EnumValueDef* v) { return v->number; }

uint32_t upb_EnumValueDef_Index(const upb_EnumValueDef* v) {
  // Compute index in our parent's array.
  return v - upb_EnumDef_Value(v->parent, 0);
}

static void create_enumvaldef(upb_DefBuilder* ctx, const char* prefix,
                              const google_protobuf_EnumValueDescriptorProto* val_proto,
                              const google_protobuf_FeatureSet* parent_features,
                              upb_EnumDef* e, upb_EnumValueDef* v) {
  UPB_DEF_SET_OPTIONS(v->opts, EnumValueDescriptorProto, EnumValueOptions,
                      val_proto);
  v->resolved_features = _upb_DefBuilder_ResolveFeatures(
      ctx, parent_features, google_protobuf_EnumValueOptions_features(v->opts));

  upb_StringView name = google_protobuf_EnumValueDescriptorProto_name(val_proto);

  v->parent = e;  // Must happen prior to _upb_DefBuilder_Add()
  v->full_name = _upb_DefBuilder_MakeFullName(ctx, prefix, name);
  v->number = google_protobuf_EnumValueDescriptorProto_number(val_proto);
  _upb_DefBuilder_Add(ctx, v->full_name,
                      _upb_DefType_Pack(v, UPB_DEFTYPE_ENUMVAL));

  bool ok = _upb_EnumDef_Insert(e, v, ctx->arena);
  if (!ok) _upb_DefBuilder_OomErr(ctx);
}

// Allocate and initialize an array of |n| enum value defs owned by |e|.
upb_EnumValueDef* _upb_EnumValueDefs_New(
    upb_DefBuilder* ctx, const char* prefix, int n,
    const google_protobuf_EnumValueDescriptorProto* const* protos,
    const google_protobuf_FeatureSet* parent_features, upb_EnumDef* e, bool* is_sorted) {
  _upb_DefType_CheckPadding(sizeof(upb_EnumValueDef));

  upb_EnumValueDef* v = UPB_DEFBUILDER_ALLOCARRAY(ctx, upb_EnumValueDef, n);

  *is_sorted = true;
  uint32_t previous = 0;
  for (int i = 0; i < n; i++) {
    create_enumvaldef(ctx, prefix, protos[i], parent_features, e, &v[i]);

    const uint32_t current = v[i].number;
    if (previous > current) *is_sorted = false;
    previous = current;
  }

  return v;
}


#include <stdint.h>


// Must be last.

struct upb_ExtensionRange {
  const google_protobuf_ExtensionRangeOptions* opts;
  const google_protobuf_FeatureSet* resolved_features;
  int32_t start;
  int32_t end;
};

upb_ExtensionRange* _upb_ExtensionRange_At(const upb_ExtensionRange* r, int i) {
  return (upb_ExtensionRange*)&r[i];
}

const google_protobuf_ExtensionRangeOptions* upb_ExtensionRange_Options(
    const upb_ExtensionRange* r) {
  return r->opts;
}

bool upb_ExtensionRange_HasOptions(const upb_ExtensionRange* r) {
  return r->opts != (void*)kUpbDefOptDefault;
}

int32_t upb_ExtensionRange_Start(const upb_ExtensionRange* r) {
  return r->start;
}

int32_t upb_ExtensionRange_End(const upb_ExtensionRange* r) { return r->end; }

upb_ExtensionRange* _upb_ExtensionRanges_New(
    upb_DefBuilder* ctx, int n,
    const google_protobuf_DescriptorProto_ExtensionRange* const* protos,
    const google_protobuf_FeatureSet* parent_features, const upb_MessageDef* m) {
  upb_ExtensionRange* r = UPB_DEFBUILDER_ALLOCARRAY(ctx, upb_ExtensionRange, n);

  for (int i = 0; i < n; i++) {
    UPB_DEF_SET_OPTIONS(r[i].opts, DescriptorProto_ExtensionRange,
                        ExtensionRangeOptions, protos[i]);
    r[i].resolved_features = _upb_DefBuilder_ResolveFeatures(
        ctx, parent_features, google_protobuf_ExtensionRangeOptions_features(r[i].opts));

    const int32_t start =
        google_protobuf_DescriptorProto_ExtensionRange_start(protos[i]);
    const int32_t end = google_protobuf_DescriptorProto_ExtensionRange_end(protos[i]);
    const int32_t max =
        google_protobuf_MessageOptions_message_set_wire_format(upb_MessageDef_Options(m))
            ? INT32_MAX
            : kUpb_MaxFieldNumber + 1;

    // A full validation would also check that each range is disjoint, and that
    // none of the fields overlap with the extension ranges, but we are just
    // sanity checking here.
    if (start < 1 || end <= start || end > max) {
      _upb_DefBuilder_Errf(ctx,
                           "Extension range (%d, %d) is invalid, message=%s\n",
                           (int)start, (int)end, upb_MessageDef_FullName(m));
    }

    r[i].start = start;
    r[i].end = end;
  }

  return r;
}


#include <ctype.h>
#include <errno.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>


// Must be last.

#define UPB_FIELD_TYPE_UNSPECIFIED 0

typedef struct {
  size_t len;
  char str[1];  // Null-terminated string data follows.
} str_t;

struct upb_FieldDef {
  UPB_ALIGN_AS(8) const google_protobuf_FieldOptions* opts;
  const google_protobuf_FeatureSet* resolved_features;
  const upb_FileDef* file;
  const upb_MessageDef* msgdef;
  const char* full_name;
  const char* json_name;
  union {
    int64_t sint;
    uint64_t uint;
    double dbl;
    float flt;
    bool boolean;
    str_t* str;
    void* msg;  // Always NULL.
  } defaultval;
  union {
    const upb_OneofDef* oneof;
    const upb_MessageDef* extension_scope;
  } scope;
  union {
    const upb_MessageDef* msgdef;
    const upb_EnumDef* enumdef;
    const google_protobuf_FieldDescriptorProto* unresolved;
  } sub;
  uint32_t number_;
  uint16_t index_;
  uint16_t layout_index;  // Index into msgdef->layout->fields or file->exts
  bool has_default;
  bool has_json_name;
  bool has_presence;
  bool is_extension;
  bool is_proto3_optional;
  upb_FieldType type_;
  upb_Label label_;
};

upb_FieldDef* _upb_FieldDef_At(const upb_FieldDef* f, int i) {
  return (upb_FieldDef*)&f[i];
}

const google_protobuf_FieldOptions* upb_FieldDef_Options(const upb_FieldDef* f) {
  return f->opts;
}

bool upb_FieldDef_HasOptions(const upb_FieldDef* f) {
  return f->opts != (void*)kUpbDefOptDefault;
}

const google_protobuf_FeatureSet* upb_FieldDef_ResolvedFeatures(const upb_FieldDef* f) {
  return f->resolved_features;
}

const char* upb_FieldDef_FullName(const upb_FieldDef* f) {
  return f->full_name;
}

upb_CType upb_FieldDef_CType(const upb_FieldDef* f) {
  return upb_FieldType_CType(f->type_);
}

upb_FieldType upb_FieldDef_Type(const upb_FieldDef* f) { return f->type_; }

uint32_t upb_FieldDef_Index(const upb_FieldDef* f) { return f->index_; }

uint32_t upb_FieldDef_LayoutIndex(const upb_FieldDef* f) {
  return f->layout_index;
}

upb_Label upb_FieldDef_Label(const upb_FieldDef* f) { return f->label_; }

uint32_t upb_FieldDef_Number(const upb_FieldDef* f) { return f->number_; }

bool upb_FieldDef_IsExtension(const upb_FieldDef* f) { return f->is_extension; }

bool _upb_FieldDef_IsPackable(const upb_FieldDef* f) {
  return upb_FieldDef_IsRepeated(f) && upb_FieldDef_IsPrimitive(f);
}

bool upb_FieldDef_IsPacked(const upb_FieldDef* f) {
  return _upb_FieldDef_IsPackable(f) &&
         google_protobuf_FeatureSet_repeated_field_encoding(f->resolved_features) ==
             google_protobuf_FeatureSet_PACKED;
}

const char* upb_FieldDef_Name(const upb_FieldDef* f) {
  return _upb_DefBuilder_FullToShort(f->full_name);
}

const char* upb_FieldDef_JsonName(const upb_FieldDef* f) {
  return f->json_name;
}

bool upb_FieldDef_HasJsonName(const upb_FieldDef* f) {
  return f->has_json_name;
}

const upb_FileDef* upb_FieldDef_File(const upb_FieldDef* f) { return f->file; }

const upb_MessageDef* upb_FieldDef_ContainingType(const upb_FieldDef* f) {
  return f->msgdef;
}

const upb_MessageDef* upb_FieldDef_ExtensionScope(const upb_FieldDef* f) {
  return f->is_extension ? f->scope.extension_scope : NULL;
}

const upb_OneofDef* upb_FieldDef_ContainingOneof(const upb_FieldDef* f) {
  return f->is_extension ? NULL : f->scope.oneof;
}

const upb_OneofDef* upb_FieldDef_RealContainingOneof(const upb_FieldDef* f) {
  const upb_OneofDef* oneof = upb_FieldDef_ContainingOneof(f);
  if (!oneof || upb_OneofDef_IsSynthetic(oneof)) return NULL;
  return oneof;
}

upb_MessageValue upb_FieldDef_Default(const upb_FieldDef* f) {
  upb_MessageValue ret;

  if (upb_FieldDef_IsRepeated(f) || upb_FieldDef_IsSubMessage(f)) {
    return (upb_MessageValue){.msg_val = NULL};
  }

  switch (upb_FieldDef_CType(f)) {
    case kUpb_CType_Bool:
      return (upb_MessageValue){.bool_val = f->defaultval.boolean};
    case kUpb_CType_Int64:
      return (upb_MessageValue){.int64_val = f->defaultval.sint};
    case kUpb_CType_UInt64:
      return (upb_MessageValue){.uint64_val = f->defaultval.uint};
    case kUpb_CType_Enum:
    case kUpb_CType_Int32:
      return (upb_MessageValue){.int32_val = (int32_t)f->defaultval.sint};
    case kUpb_CType_UInt32:
      return (upb_MessageValue){.uint32_val = (uint32_t)f->defaultval.uint};
    case kUpb_CType_Float:
      return (upb_MessageValue){.float_val = f->defaultval.flt};
    case kUpb_CType_Double:
      return (upb_MessageValue){.double_val = f->defaultval.dbl};
    case kUpb_CType_String:
    case kUpb_CType_Bytes: {
      str_t* str = f->defaultval.str;
      if (str) {
        return (upb_MessageValue){
            .str_val = (upb_StringView){.data = str->str, .size = str->len}};
      } else {
        return (upb_MessageValue){
            .str_val = (upb_StringView){.data = NULL, .size = 0}};
      }
    }
    default:
      UPB_UNREACHABLE();
  }

  return ret;
}

const upb_MessageDef* upb_FieldDef_MessageSubDef(const upb_FieldDef* f) {
  return upb_FieldDef_IsSubMessage(f) ? f->sub.msgdef : NULL;
}

const upb_EnumDef* upb_FieldDef_EnumSubDef(const upb_FieldDef* f) {
  return upb_FieldDef_IsEnum(f) ? f->sub.enumdef : NULL;
}

const upb_MiniTableField* upb_FieldDef_MiniTable(const upb_FieldDef* f) {
  if (upb_FieldDef_IsExtension(f)) {
    const upb_FileDef* file = upb_FieldDef_File(f);
    return (upb_MiniTableField*)_upb_FileDef_ExtensionMiniTable(
        file, f->layout_index);
  } else {
    const upb_MiniTable* layout = upb_MessageDef_MiniTable(f->msgdef);
    return &layout->UPB_PRIVATE(fields)[f->layout_index];
  }
}

const upb_MiniTableExtension* upb_FieldDef_MiniTableExtension(
    const upb_FieldDef* f) {
  UPB_ASSERT(upb_FieldDef_IsExtension(f));
  const upb_FileDef* file = upb_FieldDef_File(f);
  return _upb_FileDef_ExtensionMiniTable(file, f->layout_index);
}

bool _upb_FieldDef_IsClosedEnum(const upb_FieldDef* f) {
  if (f->type_ != kUpb_FieldType_Enum) return false;
  return upb_EnumDef_IsClosed(f->sub.enumdef);
}

bool _upb_FieldDef_IsProto3Optional(const upb_FieldDef* f) {
  return f->is_proto3_optional;
}

int _upb_FieldDef_LayoutIndex(const upb_FieldDef* f) { return f->layout_index; }

bool _upb_FieldDef_ValidateUtf8(const upb_FieldDef* f) {
  if (upb_FieldDef_Type(f) != kUpb_FieldType_String) return false;
  return google_protobuf_FeatureSet_utf8_validation(f->resolved_features) ==
         google_protobuf_FeatureSet_VERIFY;
}

bool _upb_FieldDef_IsGroupLike(const upb_FieldDef* f) {
  // Groups are always tag-delimited.
  if (f->type_ != kUpb_FieldType_Group) {
    return false;
  }

  const upb_MessageDef* msg = upb_FieldDef_MessageSubDef(f);

  // Group fields always are always the lowercase type name.
  const char* mname = upb_MessageDef_Name(msg);
  const char* fname = upb_FieldDef_Name(f);
  size_t name_size = strlen(fname);
  if (name_size != strlen(mname)) return false;
  for (size_t i = 0; i < name_size; ++i) {
    if ((mname[i] | 0x20) != fname[i]) {
      // Case-insensitive ascii comparison.
      return false;
    }
  }

  if (upb_MessageDef_File(msg) != upb_FieldDef_File(f)) {
    return false;
  }

  // Group messages are always defined in the same scope as the field.  File
  // level extensions will compare NULL == NULL here, which is why the file
  // comparison above is necessary to ensure both come from the same file.
  return upb_FieldDef_IsExtension(f) ? upb_FieldDef_ExtensionScope(f) ==
                                           upb_MessageDef_ContainingType(msg)
                                     : upb_FieldDef_ContainingType(f) ==
                                           upb_MessageDef_ContainingType(msg);
}

uint64_t _upb_FieldDef_Modifiers(const upb_FieldDef* f) {
  uint64_t out = upb_FieldDef_IsPacked(f) ? kUpb_FieldModifier_IsPacked : 0;

  if (upb_FieldDef_IsRepeated(f)) {
    out |= kUpb_FieldModifier_IsRepeated;
  } else if (upb_FieldDef_IsRequired(f)) {
    out |= kUpb_FieldModifier_IsRequired;
  } else if (!upb_FieldDef_HasPresence(f)) {
    out |= kUpb_FieldModifier_IsProto3Singular;
  }

  if (_upb_FieldDef_IsClosedEnum(f)) {
    out |= kUpb_FieldModifier_IsClosedEnum;
  }

  if (_upb_FieldDef_ValidateUtf8(f)) {
    out |= kUpb_FieldModifier_ValidateUtf8;
  }

  return out;
}

bool upb_FieldDef_HasDefault(const upb_FieldDef* f) { return f->has_default; }
bool upb_FieldDef_HasPresence(const upb_FieldDef* f) { return f->has_presence; }

bool upb_FieldDef_HasSubDef(const upb_FieldDef* f) {
  return upb_FieldDef_IsSubMessage(f) || upb_FieldDef_IsEnum(f);
}

bool upb_FieldDef_IsEnum(const upb_FieldDef* f) {
  return upb_FieldDef_CType(f) == kUpb_CType_Enum;
}

bool upb_FieldDef_IsMap(const upb_FieldDef* f) {
  return upb_FieldDef_IsRepeated(f) && upb_FieldDef_IsSubMessage(f) &&
         upb_MessageDef_IsMapEntry(upb_FieldDef_MessageSubDef(f));
}

bool upb_FieldDef_IsOptional(const upb_FieldDef* f) {
  return upb_FieldDef_Label(f) == kUpb_Label_Optional;
}

bool upb_FieldDef_IsPrimitive(const upb_FieldDef* f) {
  return !upb_FieldDef_IsString(f) && !upb_FieldDef_IsSubMessage(f);
}

bool upb_FieldDef_IsRepeated(const upb_FieldDef* f) {
  return upb_FieldDef_Label(f) == kUpb_Label_Repeated;
}

bool upb_FieldDef_IsRequired(const upb_FieldDef* f) {
  return google_protobuf_FeatureSet_field_presence(f->resolved_features) ==
         google_protobuf_FeatureSet_LEGACY_REQUIRED;
}

bool upb_FieldDef_IsString(const upb_FieldDef* f) {
  return upb_FieldDef_CType(f) == kUpb_CType_String ||
         upb_FieldDef_CType(f) == kUpb_CType_Bytes;
}

bool upb_FieldDef_IsSubMessage(const upb_FieldDef* f) {
  return upb_FieldDef_CType(f) == kUpb_CType_Message;
}

static bool between(int32_t x, int32_t low, int32_t high) {
  return x >= low && x <= high;
}

bool upb_FieldDef_checklabel(int32_t label) { return between(label, 1, 3); }
bool upb_FieldDef_checktype(int32_t type) { return between(type, 1, 11); }
bool upb_FieldDef_checkintfmt(int32_t fmt) { return between(fmt, 1, 3); }

bool upb_FieldDef_checkdescriptortype(int32_t type) {
  return between(type, 1, 18);
}

static bool streql2(const char* a, size_t n, const char* b) {
  return n == strlen(b) && memcmp(a, b, n) == 0;
}

// Implement the transformation as described in the spec:
//   1. upper case all letters after an underscore.
//   2. remove all underscores.
static char* make_json_name(const char* name, size_t size, upb_Arena* a) {
  char* out = upb_Arena_Malloc(a, size + 1);  // +1 is to add a trailing '\0'
  if (out == NULL) return NULL;

  bool ucase_next = false;
  char* des = out;
  for (size_t i = 0; i < size; i++) {
    if (name[i] == '_') {
      ucase_next = true;
    } else {
      *des++ = ucase_next ? toupper(name[i]) : name[i];
      ucase_next = false;
    }
  }
  *des++ = '\0';
  return out;
}

static str_t* newstr(upb_DefBuilder* ctx, const char* data, size_t len) {
  str_t* ret = _upb_DefBuilder_Alloc(ctx, sizeof(*ret) + len);
  if (!ret) _upb_DefBuilder_OomErr(ctx);
  ret->len = len;
  if (len) memcpy(ret->str, data, len);
  ret->str[len] = '\0';
  return ret;
}

static str_t* unescape(upb_DefBuilder* ctx, const upb_FieldDef* f,
                       const char* data, size_t len) {
  // Size here is an upper bound; escape sequences could ultimately shrink it.
  str_t* ret = _upb_DefBuilder_Alloc(ctx, sizeof(*ret) + len);
  char* dst = &ret->str[0];
  const char* src = data;
  const char* end = data + len;

  while (src < end) {
    if (*src == '\\') {
      src++;
      *dst++ = _upb_DefBuilder_ParseEscape(ctx, f, &src, end);
    } else {
      *dst++ = *src++;
    }
  }

  ret->len = dst - &ret->str[0];
  return ret;
}

static void parse_default(upb_DefBuilder* ctx, const char* str, size_t len,
                          upb_FieldDef* f) {
  char* end;
  char nullz[64];
  errno = 0;

  switch (upb_FieldDef_CType(f)) {
    case kUpb_CType_Int32:
    case kUpb_CType_Int64:
    case kUpb_CType_UInt32:
    case kUpb_CType_UInt64:
    case kUpb_CType_Double:
    case kUpb_CType_Float:
      // Standard C number parsing functions expect null-terminated strings.
      if (len >= sizeof(nullz) - 1) {
        _upb_DefBuilder_Errf(ctx, "Default too long: %.*s", (int)len, str);
      }
      memcpy(nullz, str, len);
      nullz[len] = '\0';
      str = nullz;
      break;
    default:
      break;
  }

  switch (upb_FieldDef_CType(f)) {
    case kUpb_CType_Int32: {
      long val = strtol(str, &end, 0);
      if (val > INT32_MAX || val < INT32_MIN || errno == ERANGE || *end) {
        goto invalid;
      }
      f->defaultval.sint = val;
      break;
    }
    case kUpb_CType_Enum: {
      const upb_EnumDef* e = f->sub.enumdef;
      const upb_EnumValueDef* ev =
          upb_EnumDef_FindValueByNameWithSize(e, str, len);
      if (!ev) {
        goto invalid;
      }
      f->defaultval.sint = upb_EnumValueDef_Number(ev);
      break;
    }
    case kUpb_CType_Int64: {
      long long val = strtoll(str, &end, 0);
      if (val > INT64_MAX || val < INT64_MIN || errno == ERANGE || *end) {
        goto invalid;
      }
      f->defaultval.sint = val;
      break;
    }
    case kUpb_CType_UInt32: {
      unsigned long val = strtoul(str, &end, 0);
      if (val > UINT32_MAX || errno == ERANGE || *end) {
        goto invalid;
      }
      f->defaultval.uint = val;
      break;
    }
    case kUpb_CType_UInt64: {
      unsigned long long val = strtoull(str, &end, 0);
      if (val > UINT64_MAX || errno == ERANGE || *end) {
        goto invalid;
      }
      f->defaultval.uint = val;
      break;
    }
    case kUpb_CType_Double: {
      double val = strtod(str, &end);
      if (errno == ERANGE || *end) {
        goto invalid;
      }
      f->defaultval.dbl = val;
      break;
    }
    case kUpb_CType_Float: {
      float val = strtof(str, &end);
      if (errno == ERANGE || *end) {
        goto invalid;
      }
      f->defaultval.flt = val;
      break;
    }
    case kUpb_CType_Bool: {
      if (streql2(str, len, "false")) {
        f->defaultval.boolean = false;
      } else if (streql2(str, len, "true")) {
        f->defaultval.boolean = true;
      } else {
        goto invalid;
      }
      break;
    }
    case kUpb_CType_String:
      f->defaultval.str = newstr(ctx, str, len);
      break;
    case kUpb_CType_Bytes:
      f->defaultval.str = unescape(ctx, f, str, len);
      break;
    case kUpb_CType_Message:
      /* Should not have a default value. */
      _upb_DefBuilder_Errf(ctx, "Message should not have a default (%s)",
                           upb_FieldDef_FullName(f));
  }

  return;

invalid:
  _upb_DefBuilder_Errf(ctx, "Invalid default '%.*s' for field %s of type %d",
                       (int)len, str, upb_FieldDef_FullName(f),
                       (int)upb_FieldDef_Type(f));
}

static void set_default_default(upb_DefBuilder* ctx, upb_FieldDef* f,
                                bool must_be_empty) {
  switch (upb_FieldDef_CType(f)) {
    case kUpb_CType_Int32:
    case kUpb_CType_Int64:
      f->defaultval.sint = 0;
      break;
    case kUpb_CType_UInt64:
    case kUpb_CType_UInt32:
      f->defaultval.uint = 0;
      break;
    case kUpb_CType_Double:
    case kUpb_CType_Float:
      f->defaultval.dbl = 0;
      break;
    case kUpb_CType_String:
    case kUpb_CType_Bytes:
      f->defaultval.str = newstr(ctx, NULL, 0);
      break;
    case kUpb_CType_Bool:
      f->defaultval.boolean = false;
      break;
    case kUpb_CType_Enum: {
      f->defaultval.sint = upb_EnumDef_Default(f->sub.enumdef);
      if (must_be_empty && f->defaultval.sint != 0) {
        _upb_DefBuilder_Errf(ctx,
                             "Implicit presence field (%s) cannot use an enum "
                             "type with a non-zero default (%s)",
                             f->full_name,
                             upb_EnumDef_FullName(f->sub.enumdef));
      }
      break;
    }
    case kUpb_CType_Message:
      break;
  }
}

static bool _upb_FieldDef_InferLegacyFeatures(
    upb_DefBuilder* ctx, upb_FieldDef* f,
    const google_protobuf_FieldDescriptorProto* proto,
    const google_protobuf_FieldOptions* options, google_protobuf_Edition edition,
    google_protobuf_FeatureSet* features) {
  bool ret = false;

  if (google_protobuf_FieldDescriptorProto_label(proto) == kUpb_Label_Required) {
    if (edition == google_protobuf_EDITION_PROTO3) {
      _upb_DefBuilder_Errf(ctx, "proto3 fields cannot be required (%s)",
                           f->full_name);
    }
    int val = google_protobuf_FeatureSet_LEGACY_REQUIRED;
    google_protobuf_FeatureSet_set_field_presence(features, val);
    ret = true;
  }

  if (google_protobuf_FieldDescriptorProto_type(proto) == kUpb_FieldType_Group) {
    int val = google_protobuf_FeatureSet_DELIMITED;
    google_protobuf_FeatureSet_set_message_encoding(features, val);
    ret = true;
  }

  if (google_protobuf_FieldOptions_has_packed(options)) {
    int val = google_protobuf_FieldOptions_packed(options) ? google_protobuf_FeatureSet_PACKED
                                                  : google_protobuf_FeatureSet_EXPANDED;
    google_protobuf_FeatureSet_set_repeated_field_encoding(features, val);
    ret = true;
  }

  return ret;
}

static void _upb_FieldDef_Create(upb_DefBuilder* ctx, const char* prefix,
                                 const google_protobuf_FeatureSet* parent_features,
                                 const google_protobuf_FieldDescriptorProto* field_proto,
                                 upb_MessageDef* m, upb_FieldDef* f) {
  // Must happen before _upb_DefBuilder_Add()
  f->file = _upb_DefBuilder_File(ctx);

  const upb_StringView name = google_protobuf_FieldDescriptorProto_name(field_proto);
  f->full_name = _upb_DefBuilder_MakeFullName(ctx, prefix, name);
  f->number_ = google_protobuf_FieldDescriptorProto_number(field_proto);
  f->is_proto3_optional =
      google_protobuf_FieldDescriptorProto_proto3_optional(field_proto);
  f->msgdef = m;
  f->scope.oneof = NULL;

  UPB_DEF_SET_OPTIONS(f->opts, FieldDescriptorProto, FieldOptions, field_proto);

  google_protobuf_Edition edition = upb_FileDef_Edition(f->file);
  const google_protobuf_FeatureSet* unresolved_features =
      google_protobuf_FieldOptions_features(f->opts);
  bool implicit = false;

  if (_upb_DefBuilder_IsLegacyEdition(edition)) {
    upb_Message_Clear(UPB_UPCAST(ctx->legacy_features),
                      UPB_DESC_MINITABLE(FeatureSet));
    if (_upb_FieldDef_InferLegacyFeatures(ctx, f, field_proto, f->opts, edition,
                                          ctx->legacy_features)) {
      implicit = true;
      unresolved_features = ctx->legacy_features;
    }
  }

  if (google_protobuf_FieldDescriptorProto_has_oneof_index(field_proto)) {
    int oneof_index = google_protobuf_FieldDescriptorProto_oneof_index(field_proto);

    if (!m) {
      _upb_DefBuilder_Errf(ctx, "oneof field (%s) has no containing msg",
                           f->full_name);
    }

    if (oneof_index < 0 || oneof_index >= upb_MessageDef_OneofCount(m)) {
      _upb_DefBuilder_Errf(ctx, "oneof_index out of range (%s)", f->full_name);
    }

    upb_OneofDef* oneof = (upb_OneofDef*)upb_MessageDef_Oneof(m, oneof_index);
    f->scope.oneof = oneof;
    parent_features = upb_OneofDef_ResolvedFeatures(oneof);

    _upb_OneofDef_Insert(ctx, oneof, f, name.data, name.size);
  }

  f->resolved_features = _upb_DefBuilder_DoResolveFeatures(
      ctx, parent_features, unresolved_features, implicit);

  f->label_ = (int)google_protobuf_FieldDescriptorProto_label(field_proto);
  if (f->label_ == kUpb_Label_Optional &&
      // TODO: remove once we can deprecate kUpb_Label_Required.
      google_protobuf_FeatureSet_field_presence(f->resolved_features) ==
          google_protobuf_FeatureSet_LEGACY_REQUIRED) {
    f->label_ = kUpb_Label_Required;
  }

  if (!google_protobuf_FieldDescriptorProto_has_name(field_proto)) {
    _upb_DefBuilder_Errf(ctx, "field has no name");
  }

  f->has_json_name = google_protobuf_FieldDescriptorProto_has_json_name(field_proto);
  if (f->has_json_name) {
    const upb_StringView sv =
        google_protobuf_FieldDescriptorProto_json_name(field_proto);
    f->json_name = upb_strdup2(sv.data, sv.size, ctx->arena);
  } else {
    f->json_name = make_json_name(name.data, name.size, ctx->arena);
  }
  if (!f->json_name) _upb_DefBuilder_OomErr(ctx);

  const bool has_type = google_protobuf_FieldDescriptorProto_has_type(field_proto);
  const bool has_type_name =
      google_protobuf_FieldDescriptorProto_has_type_name(field_proto);

  f->type_ = (int)google_protobuf_FieldDescriptorProto_type(field_proto);

  if (has_type) {
    switch (f->type_) {
      case kUpb_FieldType_Message:
      case kUpb_FieldType_Group:
      case kUpb_FieldType_Enum:
        if (!has_type_name) {
          _upb_DefBuilder_Errf(ctx, "field of type %d requires type name (%s)",
                               (int)f->type_, f->full_name);
        }
        break;
      default:
        if (has_type_name) {
          _upb_DefBuilder_Errf(
              ctx, "invalid type for field with type_name set (%s, %d)",
              f->full_name, (int)f->type_);
        }
    }
  }

  if ((!has_type && has_type_name) || f->type_ == kUpb_FieldType_Message) {
    f->type_ =
        UPB_FIELD_TYPE_UNSPECIFIED;  // We'll assign this in resolve_subdef()
  } else {
    if (f->type_ < kUpb_FieldType_Double || f->type_ > kUpb_FieldType_SInt64) {
      _upb_DefBuilder_Errf(ctx, "invalid type for field %s (%d)", f->full_name,
                           f->type_);
    }
  }

  if (f->label_ < kUpb_Label_Optional || f->label_ > kUpb_Label_Repeated) {
    _upb_DefBuilder_Errf(ctx, "invalid label for field %s (%d)", f->full_name,
                         f->label_);
  }

  /* We can't resolve the subdef or (in the case of extensions) the containing
   * message yet, because it may not have been defined yet.  We stash a pointer
   * to the field_proto until later when we can properly resolve it. */
  f->sub.unresolved = field_proto;

  if (google_protobuf_FieldDescriptorProto_has_oneof_index(field_proto)) {
    if (upb_FieldDef_Label(f) != kUpb_Label_Optional) {
      _upb_DefBuilder_Errf(ctx, "fields in oneof must have OPTIONAL label (%s)",
                           f->full_name);
    }
  }

  f->has_presence =
      (!upb_FieldDef_IsRepeated(f)) &&
      (f->is_extension || _upb_FileDef_ImplicitFieldPresenceDisabled(f->file) ||
       (f->type_ == kUpb_FieldType_Message ||
        f->type_ == kUpb_FieldType_Group || upb_FieldDef_ContainingOneof(f) ||
        google_protobuf_FeatureSet_field_presence(f->resolved_features) !=
            google_protobuf_FeatureSet_IMPLICIT));
}

static void _upb_FieldDef_CreateExt(
    upb_DefBuilder* ctx, const char* prefix,
    const google_protobuf_FeatureSet* parent_features,
    const google_protobuf_FieldDescriptorProto* field_proto, upb_MessageDef* m,
    upb_FieldDef* f) {
  f->is_extension = true;
  _upb_FieldDef_Create(ctx, prefix, parent_features, field_proto, m, f);

  if (google_protobuf_FieldDescriptorProto_has_oneof_index(field_proto)) {
    _upb_DefBuilder_Errf(ctx, "oneof_index provided for extension field (%s)",
                         f->full_name);
  }

  f->scope.extension_scope = m;
  _upb_DefBuilder_Add(ctx, f->full_name, _upb_DefType_Pack(f, UPB_DEFTYPE_EXT));
  f->layout_index = ctx->ext_count++;

  if (ctx->layout) {
    UPB_ASSERT(upb_MiniTableExtension_Number(
                   upb_FieldDef_MiniTableExtension(f)) == f->number_);
  }
}

static void _upb_FieldDef_CreateNotExt(
    upb_DefBuilder* ctx, const char* prefix,
    const google_protobuf_FeatureSet* parent_features,
    const google_protobuf_FieldDescriptorProto* field_proto, upb_MessageDef* m,
    upb_FieldDef* f) {
  f->is_extension = false;
  _upb_FieldDef_Create(ctx, prefix, parent_features, field_proto, m, f);

  if (!google_protobuf_FieldDescriptorProto_has_oneof_index(field_proto)) {
    if (f->is_proto3_optional) {
      _upb_DefBuilder_Errf(
          ctx,
          "non-extension field (%s) with proto3_optional was not in a oneof",
          f->full_name);
    }
  }

  _upb_MessageDef_InsertField(ctx, m, f);
}

upb_FieldDef* _upb_Extensions_New(
    upb_DefBuilder* ctx, int n,
    const google_protobuf_FieldDescriptorProto* const* protos,
    const google_protobuf_FeatureSet* parent_features, const char* prefix,
    upb_MessageDef* m) {
  _upb_DefType_CheckPadding(sizeof(upb_FieldDef));
  upb_FieldDef* defs = UPB_DEFBUILDER_ALLOCARRAY(ctx, upb_FieldDef, n);

  for (int i = 0; i < n; i++) {
    upb_FieldDef* f = &defs[i];

    _upb_FieldDef_CreateExt(ctx, prefix, parent_features, protos[i], m, f);
    f->index_ = i;
  }

  return defs;
}

upb_FieldDef* _upb_FieldDefs_New(
    upb_DefBuilder* ctx, int n,
    const google_protobuf_FieldDescriptorProto* const* protos,
    const google_protobuf_FeatureSet* parent_features, const char* prefix,
    upb_MessageDef* m, bool* is_sorted) {
  _upb_DefType_CheckPadding(sizeof(upb_FieldDef));
  upb_FieldDef* defs = UPB_DEFBUILDER_ALLOCARRAY(ctx, upb_FieldDef, n);

  uint32_t previous = 0;
  for (int i = 0; i < n; i++) {
    upb_FieldDef* f = &defs[i];

    _upb_FieldDef_CreateNotExt(ctx, prefix, parent_features, protos[i], m, f);
    f->index_ = i;
    if (!ctx->layout) {
      // Speculate that the def fields are sorted.  We will always sort the
      // MiniTable fields, so if defs are sorted then indices will match.
      //
      // If this is incorrect, we will overwrite later.
      f->layout_index = i;
    }

    const uint32_t current = f->number_;
    if (previous > current) *is_sorted = false;
    previous = current;
  }

  return defs;
}

static void resolve_subdef(upb_DefBuilder* ctx, const char* prefix,
                           upb_FieldDef* f) {
  const google_protobuf_FieldDescriptorProto* field_proto = f->sub.unresolved;
  upb_StringView name = google_protobuf_FieldDescriptorProto_type_name(field_proto);
  bool has_name = google_protobuf_FieldDescriptorProto_has_type_name(field_proto);
  switch ((int)f->type_) {
    case UPB_FIELD_TYPE_UNSPECIFIED: {
      // Type was not specified and must be inferred.
      UPB_ASSERT(has_name);
      upb_deftype_t type;
      const void* def =
          _upb_DefBuilder_ResolveAny(ctx, f->full_name, prefix, name, &type);
      switch (type) {
        case UPB_DEFTYPE_ENUM:
          f->sub.enumdef = def;
          f->type_ = kUpb_FieldType_Enum;
          break;
        case UPB_DEFTYPE_MSG:
          f->sub.msgdef = def;
          f->type_ = kUpb_FieldType_Message;
          // TODO: remove once we can deprecate
          // kUpb_FieldType_Group.
          if (google_protobuf_FeatureSet_message_encoding(f->resolved_features) ==
                  google_protobuf_FeatureSet_DELIMITED &&
              !upb_MessageDef_IsMapEntry(def) &&
              !(f->msgdef && upb_MessageDef_IsMapEntry(f->msgdef))) {
            f->type_ = kUpb_FieldType_Group;
          }
          f->has_presence = !upb_FieldDef_IsRepeated(f);
          break;
        default:
          _upb_DefBuilder_Errf(ctx, "Couldn't resolve type name for field %s",
                               f->full_name);
      }
      break;
    }
    case kUpb_FieldType_Message:
    case kUpb_FieldType_Group:
      UPB_ASSERT(has_name);
      f->sub.msgdef = _upb_DefBuilder_Resolve(ctx, f->full_name, prefix, name,
                                              UPB_DEFTYPE_MSG);
      break;
    case kUpb_FieldType_Enum:
      UPB_ASSERT(has_name);
      f->sub.enumdef = _upb_DefBuilder_Resolve(ctx, f->full_name, prefix, name,
                                               UPB_DEFTYPE_ENUM);
      break;
    default:
      // No resolution necessary.
      break;
  }
}

static int _upb_FieldDef_Compare(const void* p1, const void* p2) {
  const uint32_t v1 = (*(upb_FieldDef**)p1)->number_;
  const uint32_t v2 = (*(upb_FieldDef**)p2)->number_;
  return (v1 < v2) ? -1 : (v1 > v2);
}

// _upb_FieldDefs_Sorted() is mostly a pure function of its inputs, but has one
// critical side effect that we depend on: it sets layout_index appropriately
// for non-sorted lists of fields.
const upb_FieldDef** _upb_FieldDefs_Sorted(const upb_FieldDef* f, int n,
                                           upb_Arena* a) {
  // TODO: Replace this arena alloc with a persistent scratch buffer.
  upb_FieldDef** out = (upb_FieldDef**)upb_Arena_Malloc(a, n * sizeof(void*));
  if (!out) return NULL;

  for (int i = 0; i < n; i++) {
    out[i] = (upb_FieldDef*)&f[i];
  }
  qsort(out, n, sizeof(void*), _upb_FieldDef_Compare);

  for (int i = 0; i < n; i++) {
    out[i]->layout_index = i;
  }
  return (const upb_FieldDef**)out;
}

bool upb_FieldDef_MiniDescriptorEncode(const upb_FieldDef* f, upb_Arena* a,
                                       upb_StringView* out) {
  UPB_ASSERT(f->is_extension);

  upb_DescState s;
  _upb_DescState_Init(&s);

  const int number = upb_FieldDef_Number(f);
  const uint64_t modifiers = _upb_FieldDef_Modifiers(f);

  if (!_upb_DescState_Grow(&s, a)) return false;
  s.ptr = upb_MtDataEncoder_EncodeExtension(&s.e, s.ptr, f->type_, number,
                                            modifiers);
  *s.ptr = '\0';

  out->data = s.buf;
  out->size = s.ptr - s.buf;
  return true;
}

static void resolve_extension(upb_DefBuilder* ctx, const char* prefix,
                              upb_FieldDef* f,
                              const google_protobuf_FieldDescriptorProto* field_proto) {
  if (!google_protobuf_FieldDescriptorProto_has_extendee(field_proto)) {
    _upb_DefBuilder_Errf(ctx, "extension for field '%s' had no extendee",
                         f->full_name);
  }

  upb_StringView name = google_protobuf_FieldDescriptorProto_extendee(field_proto);
  const upb_MessageDef* m =
      _upb_DefBuilder_Resolve(ctx, f->full_name, prefix, name, UPB_DEFTYPE_MSG);
  f->msgdef = m;

  if (!_upb_MessageDef_IsValidExtensionNumber(m, f->number_)) {
    _upb_DefBuilder_Errf(
        ctx,
        "field number %u in extension %s has no extension range in message %s",
        (unsigned)f->number_, f->full_name, upb_MessageDef_FullName(m));
  }
}

void _upb_FieldDef_BuildMiniTableExtension(upb_DefBuilder* ctx,
                                           const upb_FieldDef* f) {
  const upb_MiniTableExtension* ext = upb_FieldDef_MiniTableExtension(f);

  if (ctx->layout) {
    UPB_ASSERT(upb_FieldDef_Number(f) == upb_MiniTableExtension_Number(ext));
  } else {
    upb_StringView desc;
    if (!upb_FieldDef_MiniDescriptorEncode(f, ctx->tmp_arena, &desc)) {
      _upb_DefBuilder_OomErr(ctx);
    }

    upb_MiniTableExtension* mut_ext = (upb_MiniTableExtension*)ext;
    upb_MiniTableSub sub = {NULL};
    if (upb_FieldDef_IsSubMessage(f)) {
      const upb_MiniTable* submsg = upb_MessageDef_MiniTable(f->sub.msgdef);
      sub = upb_MiniTableSub_FromMessage(submsg);
    } else if (_upb_FieldDef_IsClosedEnum(f)) {
      const upb_MiniTableEnum* subenum = _upb_EnumDef_MiniTable(f->sub.enumdef);
      sub = upb_MiniTableSub_FromEnum(subenum);
    }
    bool ok2 = _upb_MiniTableExtension_Init(desc.data, desc.size, mut_ext,
                                            upb_MessageDef_MiniTable(f->msgdef),
                                            sub, ctx->platform, ctx->status);
    if (!ok2) _upb_DefBuilder_Errf(ctx, "Could not build extension mini table");
  }

  bool ok = _upb_DefPool_InsertExt(ctx->symtab, ext, f);
  if (!ok) _upb_DefBuilder_OomErr(ctx);
}

static void resolve_default(upb_DefBuilder* ctx, upb_FieldDef* f,
                            const google_protobuf_FieldDescriptorProto* field_proto) {
  // Implicit presence fields should always have an effective default of 0.
  // This should naturally fall out of the validations that protoc performs:
  // - Implicit presence fields cannot specify a default value.
  // - Implicit presence fields for for enums can only use open enums, which
  //   are required to have zero as their default.
  //   - Even if we are treating all enums as open, the proto compiler will
  //     still reject using a nominally closed enum with an implicit presence
  //     field.
  bool must_be_empty = !f->has_presence && !upb_FieldDef_IsRepeated(f);

  // Have to delay resolving of the default value until now because of the enum
  // case, since enum defaults are specified with a label.
  if (google_protobuf_FieldDescriptorProto_has_default_value(field_proto)) {
    upb_StringView defaultval =
        google_protobuf_FieldDescriptorProto_default_value(field_proto);

    if (must_be_empty) {
      _upb_DefBuilder_Errf(ctx,
                           "fields with implicit presence cannot have "
                           "explicit defaults (%s)",
                           f->full_name);
    }

    if (upb_FileDef_Edition(f->file) == google_protobuf_EDITION_PROTO3) {
      _upb_DefBuilder_Errf(ctx,
                           "proto3 fields cannot have explicit defaults (%s)",
                           f->full_name);
    }

    if (upb_FieldDef_IsSubMessage(f)) {
      _upb_DefBuilder_Errf(ctx,
                           "message fields cannot have explicit defaults (%s)",
                           f->full_name);
    }

    parse_default(ctx, defaultval.data, defaultval.size, f);
    f->has_default = true;
  } else {
    set_default_default(ctx, f, must_be_empty);
    f->has_default = false;
  }
}

void _upb_FieldDef_Resolve(upb_DefBuilder* ctx, const char* prefix,
                           upb_FieldDef* f) {
  // We have to stash this away since resolve_subdef() may overwrite it.
  const google_protobuf_FieldDescriptorProto* field_proto = f->sub.unresolved;

  resolve_subdef(ctx, prefix, f);
  resolve_default(ctx, f, field_proto);

  if (f->is_extension) {
    resolve_extension(ctx, prefix, f, field_proto);
  }
}


#include <stddef.h>
#include <stdint.h>
#include <string.h>


// Must be last.

struct upb_FileDef {
  const google_protobuf_FileOptions* opts;
  const google_protobuf_FeatureSet* resolved_features;
  const char* name;
  const char* package;
  google_protobuf_Edition edition;

  const upb_FileDef** deps;
  const int32_t* public_deps;
  const int32_t* weak_deps;
  const upb_MessageDef* top_lvl_msgs;
  const upb_EnumDef* top_lvl_enums;
  const upb_FieldDef* top_lvl_exts;
  const upb_ServiceDef* services;
  const upb_MiniTableExtension** ext_layouts;
  const upb_DefPool* symtab;

  int dep_count;
  int public_dep_count;
  int weak_dep_count;
  int top_lvl_msg_count;
  int top_lvl_enum_count;
  int top_lvl_ext_count;
  int service_count;
  int ext_count;  // All exts in the file.
};

UPB_API const char* upb_FileDef_EditionName(int edition) {
  // TODO Synchronize this with descriptor.proto better.
  switch (edition) {
    case google_protobuf_EDITION_PROTO2:
      return "PROTO2";
    case google_protobuf_EDITION_PROTO3:
      return "PROTO3";
    case google_protobuf_EDITION_2023:
      return "2023";
    default:
      return "UNKNOWN";
  }
}

const google_protobuf_FileOptions* upb_FileDef_Options(const upb_FileDef* f) {
  return f->opts;
}

const google_protobuf_FeatureSet* upb_FileDef_ResolvedFeatures(const upb_FileDef* f) {
  return f->resolved_features;
}

bool upb_FileDef_HasOptions(const upb_FileDef* f) {
  return f->opts != (void*)kUpbDefOptDefault;
}

const char* upb_FileDef_Name(const upb_FileDef* f) { return f->name; }

const char* upb_FileDef_Package(const upb_FileDef* f) {
  return f->package ? f->package : "";
}

google_protobuf_Edition upb_FileDef_Edition(const upb_FileDef* f) { return f->edition; }

const char* _upb_FileDef_RawPackage(const upb_FileDef* f) { return f->package; }

int upb_FileDef_TopLevelMessageCount(const upb_FileDef* f) {
  return f->top_lvl_msg_count;
}

int upb_FileDef_DependencyCount(const upb_FileDef* f) { return f->dep_count; }

int upb_FileDef_PublicDependencyCount(const upb_FileDef* f) {
  return f->public_dep_count;
}

int upb_FileDef_WeakDependencyCount(const upb_FileDef* f) {
  return f->weak_dep_count;
}

const int32_t* _upb_FileDef_PublicDependencyIndexes(const upb_FileDef* f) {
  return f->public_deps;
}

const int32_t* _upb_FileDef_WeakDependencyIndexes(const upb_FileDef* f) {
  return f->weak_deps;
}

bool _upb_FileDef_ClosedEnumCheckingDisabled(const upb_FileDef* f) {
  return upb_DefPool_ClosedEnumCheckingDisabled(f->symtab);
}

bool _upb_FileDef_ImplicitFieldPresenceDisabled(const upb_FileDef* f) {
  return upb_DefPool_ImplicitFieldPresenceDisabled(f->symtab);
}

int upb_FileDef_TopLevelEnumCount(const upb_FileDef* f) {
  return f->top_lvl_enum_count;
}

int upb_FileDef_TopLevelExtensionCount(const upb_FileDef* f) {
  return f->top_lvl_ext_count;
}

int upb_FileDef_ServiceCount(const upb_FileDef* f) { return f->service_count; }

const upb_FileDef* upb_FileDef_Dependency(const upb_FileDef* f, int i) {
  UPB_ASSERT(0 <= i && i < f->dep_count);
  return f->deps[i];
}

const upb_FileDef* upb_FileDef_PublicDependency(const upb_FileDef* f, int i) {
  UPB_ASSERT(0 <= i && i < f->public_dep_count);
  return f->deps[f->public_deps[i]];
}

const upb_FileDef* upb_FileDef_WeakDependency(const upb_FileDef* f, int i) {
  UPB_ASSERT(0 <= i && i < f->public_dep_count);
  return f->deps[f->weak_deps[i]];
}

const upb_MessageDef* upb_FileDef_TopLevelMessage(const upb_FileDef* f, int i) {
  UPB_ASSERT(0 <= i && i < f->top_lvl_msg_count);
  return _upb_MessageDef_At(f->top_lvl_msgs, i);
}

const upb_EnumDef* upb_FileDef_TopLevelEnum(const upb_FileDef* f, int i) {
  UPB_ASSERT(0 <= i && i < f->top_lvl_enum_count);
  return _upb_EnumDef_At(f->top_lvl_enums, i);
}

const upb_FieldDef* upb_FileDef_TopLevelExtension(const upb_FileDef* f, int i) {
  UPB_ASSERT(0 <= i && i < f->top_lvl_ext_count);
  return _upb_FieldDef_At(f->top_lvl_exts, i);
}

const upb_ServiceDef* upb_FileDef_Service(const upb_FileDef* f, int i) {
  UPB_ASSERT(0 <= i && i < f->service_count);
  return _upb_ServiceDef_At(f->services, i);
}

const upb_DefPool* upb_FileDef_Pool(const upb_FileDef* f) { return f->symtab; }

const upb_MiniTableExtension* _upb_FileDef_ExtensionMiniTable(
    const upb_FileDef* f, int i) {
  return f->ext_layouts[i];
}

// Note: Import cycles are not allowed so this will terminate.
bool upb_FileDef_Resolves(const upb_FileDef* f, const char* path) {
  if (!strcmp(f->name, path)) return true;

  for (int i = 0; i < upb_FileDef_PublicDependencyCount(f); i++) {
    const upb_FileDef* dep = upb_FileDef_PublicDependency(f, i);
    if (upb_FileDef_Resolves(dep, path)) return true;
  }
  return false;
}

static char* _strviewdup(upb_DefBuilder* ctx, upb_StringView view) {
  char* ret = upb_strdup2(view.data, view.size, _upb_DefBuilder_Arena(ctx));
  if (!ret) _upb_DefBuilder_OomErr(ctx);
  return ret;
}

static bool streql_view(upb_StringView view, const char* b) {
  return view.size == strlen(b) && memcmp(view.data, b, view.size) == 0;
}

static int count_exts_in_msg(const google_protobuf_DescriptorProto* msg_proto) {
  size_t n;
  google_protobuf_DescriptorProto_extension(msg_proto, &n);
  int ext_count = n;

  const google_protobuf_DescriptorProto* const* nested_msgs =
      google_protobuf_DescriptorProto_nested_type(msg_proto, &n);
  for (size_t i = 0; i < n; i++) {
    ext_count += count_exts_in_msg(nested_msgs[i]);
  }

  return ext_count;
}

const google_protobuf_FeatureSet* _upb_FileDef_FindEdition(upb_DefBuilder* ctx,
                                                  int edition) {
  const google_protobuf_FeatureSetDefaults* defaults =
      upb_DefPool_FeatureSetDefaults(ctx->symtab);

  int min = google_protobuf_FeatureSetDefaults_minimum_edition(defaults);
  int max = google_protobuf_FeatureSetDefaults_maximum_edition(defaults);
  if (edition < min) {
    _upb_DefBuilder_Errf(ctx,
                         "Edition %s is earlier than the minimum edition %s "
                         "given in the defaults",
                         upb_FileDef_EditionName(edition),
                         upb_FileDef_EditionName(min));
    return NULL;
  }
  if (edition > max && edition != google_protobuf_EDITION_UNSTABLE) {
    _upb_DefBuilder_Errf(ctx,
                         "Edition %s is later than the maximum edition %s "
                         "given in the defaults",
                         upb_FileDef_EditionName(edition),
                         upb_FileDef_EditionName(max));
    return NULL;
  }

  size_t n;
  const google_protobuf_FeatureSetDefaults_FeatureSetEditionDefault* const* d =
      google_protobuf_FeatureSetDefaults_defaults(defaults, &n);
  const google_protobuf_FeatureSetDefaults_FeatureSetEditionDefault* result = NULL;
  for (size_t i = 0; i < n; i++) {
    if (google_protobuf_FeatureSetDefaults_FeatureSetEditionDefault_edition(d[i]) >
        edition) {
      break;
    }
    result = d[i];
  }
  if (result == NULL) {
    _upb_DefBuilder_Errf(ctx, "No valid default found for edition %s",
                         upb_FileDef_EditionName(edition));
    return NULL;
  }

  // Merge the fixed and overridable features to get the edition's default
  // feature set.
  const google_protobuf_FeatureSet* fixed =
      google_protobuf_FeatureSetDefaults_FeatureSetEditionDefault_fixed_features(result);
  const google_protobuf_FeatureSet* overridable =
      google_protobuf_FeatureSetDefaults_FeatureSetEditionDefault_overridable_features(
          result);
  if (!fixed && !overridable) {
    _upb_DefBuilder_Errf(ctx, "No valid default found for edition %s",
                         upb_FileDef_EditionName(edition));
    return NULL;
  } else if (!fixed) {
    return overridable;
  }
  return _upb_DefBuilder_DoResolveFeatures(ctx, fixed, overridable,
                                           /*is_implicit=*/true);
}

// Allocate and initialize one file def, and add it to the context object.
void _upb_FileDef_Create(upb_DefBuilder* ctx,
                         const google_protobuf_FileDescriptorProto* file_proto) {
  upb_FileDef* file = _upb_DefBuilder_Alloc(ctx, sizeof(upb_FileDef));
  ctx->file = file;

  const google_protobuf_DescriptorProto* const* msgs;
  const google_protobuf_EnumDescriptorProto* const* enums;
  const google_protobuf_FieldDescriptorProto* const* exts;
  const google_protobuf_ServiceDescriptorProto* const* services;
  const upb_StringView* strs;
  const int32_t* public_deps;
  const int32_t* weak_deps;
  size_t n;

  file->symtab = ctx->symtab;

  // Count all extensions in the file, to build a flat array of layouts.
  google_protobuf_FileDescriptorProto_extension(file_proto, &n);
  int ext_count = n;
  msgs = google_protobuf_FileDescriptorProto_message_type(file_proto, &n);
  for (size_t i = 0; i < n; i++) {
    ext_count += count_exts_in_msg(msgs[i]);
  }
  file->ext_count = ext_count;

  if (ctx->layout) {
    // We are using the ext layouts that were passed in.
    file->ext_layouts = ctx->layout->UPB_PRIVATE(exts);
    const int mt_ext_count = upb_MiniTableFile_ExtensionCount(ctx->layout);
    if (mt_ext_count != file->ext_count) {
      _upb_DefBuilder_Errf(ctx,
                           "Extension count did not match layout (%d vs %d)",
                           mt_ext_count, file->ext_count);
    }
  } else {
    // We are building ext layouts from scratch.
    file->ext_layouts = _upb_DefBuilder_Alloc(
        ctx, sizeof(*file->ext_layouts) * file->ext_count);
    upb_MiniTableExtension* ext =
        UPB_DEFBUILDER_ALLOCARRAY(ctx, upb_MiniTableExtension, file->ext_count);
    for (int i = 0; i < file->ext_count; i++) {
      file->ext_layouts[i] = &ext[i];
    }
  }

  upb_StringView name = google_protobuf_FileDescriptorProto_name(file_proto);
  file->name = _strviewdup(ctx, name);
  if (strlen(file->name) != name.size) {
    _upb_DefBuilder_Errf(ctx, "File name contained embedded NULL");
  }

  upb_StringView package = google_protobuf_FileDescriptorProto_package(file_proto);

  if (package.size) {
    _upb_DefBuilder_CheckIdentFull(ctx, package);
    file->package = _strviewdup(ctx, package);
  } else {
    file->package = NULL;
  }

  upb_StringView syntax = google_protobuf_FileDescriptorProto_syntax(file_proto);

  if (google_protobuf_FileDescriptorProto_has_edition(file_proto)) {
    if (!streql_view(syntax, "editions")) {
      _upb_DefBuilder_Errf(ctx,
                           "Setting edition requires that syntax=\"editions\", "
                           "but syntax is \"" UPB_STRINGVIEW_FORMAT "\"",
                           UPB_STRINGVIEW_ARGS(syntax));
    }
    file->edition = google_protobuf_FileDescriptorProto_edition(file_proto);
  } else if (google_protobuf_FileDescriptorProto_has_syntax(file_proto)) {
    if (streql_view(syntax, "proto2")) {
      file->edition = google_protobuf_EDITION_PROTO2;
    } else if (streql_view(syntax, "proto3")) {
      file->edition = google_protobuf_EDITION_PROTO3;
    } else if (streql_view(syntax, "editions")) {
      _upb_DefBuilder_Errf(
          ctx, "File has syntax=\"editions\", but no edition is specified");
    } else {
      _upb_DefBuilder_Errf(ctx, "Invalid syntax '" UPB_STRINGVIEW_FORMAT "'",
                           UPB_STRINGVIEW_ARGS(syntax));
    }
  } else {
    // The legacy default when no edition or syntax is specified is proto2.
    file->edition = google_protobuf_EDITION_PROTO2;
  }

  // Read options.
  UPB_DEF_SET_OPTIONS(file->opts, FileDescriptorProto, FileOptions, file_proto);

  // Resolve features.
  const google_protobuf_FeatureSet* edition_defaults =
      _upb_FileDef_FindEdition(ctx, file->edition);
  const google_protobuf_FeatureSet* unresolved = google_protobuf_FileOptions_features(file->opts);
  file->resolved_features =
      _upb_DefBuilder_ResolveFeatures(ctx, edition_defaults, unresolved);

  // Verify dependencies.
  strs = google_protobuf_FileDescriptorProto_dependency(file_proto, &n);
  file->dep_count = n;
  file->deps = UPB_DEFBUILDER_ALLOCARRAY(ctx, const upb_FileDef*, n);

  for (size_t i = 0; i < n; i++) {
    upb_StringView str = strs[i];
    file->deps[i] =
        upb_DefPool_FindFileByNameWithSize(ctx->symtab, str.data, str.size);
    if (!file->deps[i]) {
      _upb_DefBuilder_Errf(ctx,
                           "Depends on file '" UPB_STRINGVIEW_FORMAT
                           "', but it has not been loaded",
                           UPB_STRINGVIEW_ARGS(str));
    }
  }

  public_deps = google_protobuf_FileDescriptorProto_public_dependency(file_proto, &n);
  file->public_dep_count = n;
  file->public_deps = UPB_DEFBUILDER_ALLOCARRAY(ctx, int32_t, n);
  int32_t* mutable_public_deps = (int32_t*)file->public_deps;
  for (size_t i = 0; i < n; i++) {
    if (public_deps[i] >= file->dep_count) {
      _upb_DefBuilder_Errf(ctx, "public_dep %d is out of range",
                           (int)public_deps[i]);
    }
    mutable_public_deps[i] = public_deps[i];
  }

  weak_deps = google_protobuf_FileDescriptorProto_weak_dependency(file_proto, &n);
  file->weak_dep_count = n;
  file->weak_deps = UPB_DEFBUILDER_ALLOCARRAY(ctx, const int32_t, n);
  int32_t* mutable_weak_deps = (int32_t*)file->weak_deps;
  for (size_t i = 0; i < n; i++) {
    if (weak_deps[i] >= file->dep_count) {
      _upb_DefBuilder_Errf(ctx, "weak_dep %d is out of range",
                           (int)weak_deps[i]);
    }
    mutable_weak_deps[i] = weak_deps[i];
  }

  // Create enums.
  enums = google_protobuf_FileDescriptorProto_enum_type(file_proto, &n);
  file->top_lvl_enum_count = n;
  file->top_lvl_enums =
      _upb_EnumDefs_New(ctx, n, enums, file->resolved_features, NULL);

  // Create extensions.
  exts = google_protobuf_FileDescriptorProto_extension(file_proto, &n);
  file->top_lvl_ext_count = n;
  file->top_lvl_exts = _upb_Extensions_New(
      ctx, n, exts, file->resolved_features, file->package, NULL);

  // Create messages.
  msgs = google_protobuf_FileDescriptorProto_message_type(file_proto, &n);
  file->top_lvl_msg_count = n;
  file->top_lvl_msgs =
      _upb_MessageDefs_New(ctx, n, msgs, file->resolved_features, NULL);

  // Create services.
  services = google_protobuf_FileDescriptorProto_service(file_proto, &n);
  file->service_count = n;
  file->services =
      _upb_ServiceDefs_New(ctx, n, services, file->resolved_features);

  // Now that all names are in the table, build layouts and resolve refs.

  for (int i = 0; i < file->top_lvl_msg_count; i++) {
    upb_MessageDef* m = (upb_MessageDef*)upb_FileDef_TopLevelMessage(file, i);
    _upb_MessageDef_Resolve(ctx, m);
  }

  for (int i = 0; i < file->top_lvl_ext_count; i++) {
    upb_FieldDef* f = (upb_FieldDef*)upb_FileDef_TopLevelExtension(file, i);
    _upb_FieldDef_Resolve(ctx, file->package, f);
  }

  for (int i = 0; i < file->top_lvl_msg_count; i++) {
    upb_MessageDef* m = (upb_MessageDef*)upb_FileDef_TopLevelMessage(file, i);
    _upb_MessageDef_CreateMiniTable(ctx, (upb_MessageDef*)m);
  }

  for (int i = 0; i < file->top_lvl_ext_count; i++) {
    upb_FieldDef* f = (upb_FieldDef*)upb_FileDef_TopLevelExtension(file, i);
    _upb_FieldDef_BuildMiniTableExtension(ctx, f);
  }

  for (int i = 0; i < file->top_lvl_msg_count; i++) {
    upb_MessageDef* m = (upb_MessageDef*)upb_FileDef_TopLevelMessage(file, i);
    _upb_MessageDef_LinkMiniTable(ctx, m);
  }

  if (file->ext_count) {
    upb_ExtensionRegistryStatus status = upb_ExtensionRegistry_AddArray(
        _upb_DefPool_ExtReg(ctx->symtab), file->ext_layouts, file->ext_count);
    if (status != kUpb_ExtensionRegistryStatus_Ok) {
      if (status == kUpb_ExtensionRegistryStatus_OutOfMemory) {
        _upb_DefBuilder_OomErr(ctx);
      }

      UPB_ASSERT(status == kUpb_ExtensionRegistryStatus_DuplicateEntry);
      _upb_DefBuilder_Errf(ctx, "duplicate extension entry");
    }
  }
}


#include <assert.h>
#include <stdarg.h>
#include <stdint.h>
#include <string.h>


// Must be last.

/* The upb core does not generally have a concept of default instances. However
 * for descriptor options we make an exception since the max size is known and
 * modest (<200 bytes). All types can share a default instance since it is
 * initialized to zeroes.
 *
 * We have to allocate an extra pointer for upb's internal metadata. */
static UPB_ALIGN_AS(8) const
    char opt_default_buf[_UPB_MAXOPT_SIZE + sizeof(void*)] = {0};
const char* kUpbDefOptDefault = &opt_default_buf[sizeof(void*)];

const char* _upb_DefBuilder_FullToShort(const char* fullname) {
  const char* p;

  if (fullname == NULL) {
    return NULL;
  } else if ((p = strrchr(fullname, '.')) == NULL) {
    /* No '.' in the name, return the full string. */
    return fullname;
  } else {
    /* Return one past the last '.'. */
    return p + 1;
  }
}

void _upb_DefBuilder_FailJmp(upb_DefBuilder* ctx) { UPB_LONGJMP(ctx->err, 1); }

void _upb_DefBuilder_Errf(upb_DefBuilder* ctx, const char* fmt, ...) {
  va_list argp;
  va_start(argp, fmt);
  upb_Status_VSetErrorFormat(ctx->status, fmt, argp);
  va_end(argp);
  _upb_DefBuilder_FailJmp(ctx);
}

void _upb_DefBuilder_OomErr(upb_DefBuilder* ctx) {
  upb_Status_SetErrorMessage(ctx->status, "out of memory");
  _upb_DefBuilder_FailJmp(ctx);
}

// Verify a relative identifier string. The loop is branchless for speed.
static void _upb_DefBuilder_CheckIdentNotFull(upb_DefBuilder* ctx,
                                              upb_StringView name) {
  bool good = name.size > 0;

  for (size_t i = 0; i < name.size; i++) {
    const char c = name.data[i];
    const char d = c | 0x20;  // force lowercase
    const bool is_alpha = (('a' <= d) & (d <= 'z')) | (c == '_');
    const bool is_numer = ('0' <= c) & (c <= '9') & (i != 0);

    good &= is_alpha | is_numer;
  }

  if (!good) _upb_DefBuilder_CheckIdentSlow(ctx, name, false);
}

const char* _upb_DefBuilder_MakeFullName(upb_DefBuilder* ctx,
                                         const char* prefix,
                                         upb_StringView name) {
  _upb_DefBuilder_CheckIdentNotFull(ctx, name);
  if (prefix) {
    // ret = prefix + '.' + name;
    size_t n = strlen(prefix);
    char* ret = _upb_DefBuilder_Alloc(ctx, n + name.size + 2);
    strcpy(ret, prefix);
    ret[n] = '.';
    memcpy(&ret[n + 1], name.data, name.size);
    ret[n + 1 + name.size] = '\0';
    return ret;
  } else {
    char* ret = upb_strdup2(name.data, name.size, ctx->arena);
    if (!ret) _upb_DefBuilder_OomErr(ctx);
    return ret;
  }
}

static bool remove_component(char* base, size_t* len) {
  if (*len == 0) return false;

  for (size_t i = *len - 1; i > 0; i--) {
    if (base[i] == '.') {
      *len = i;
      return true;
    }
  }

  *len = 0;
  return true;
}

const void* _upb_DefBuilder_ResolveAny(upb_DefBuilder* ctx,
                                       const char* from_name_dbg,
                                       const char* base, upb_StringView sym,
                                       upb_deftype_t* type) {
  if (sym.size == 0) goto notfound;
  upb_value v;
  if (sym.data[0] == '.') {
    // Symbols starting with '.' are absolute, so we do a single lookup.
    // Slice to omit the leading '.'
    if (!_upb_DefPool_LookupSym(ctx->symtab, sym.data + 1, sym.size - 1, &v)) {
      goto notfound;
    }
  } else {
    // Remove components from base until we find an entry or run out.
    size_t baselen = base ? strlen(base) : 0;
    char* tmp = upb_gmalloc(sym.size + baselen + 1);
    while (1) {
      char* p = tmp;
      if (baselen) {
        memcpy(p, base, baselen);
        p[baselen] = '.';
        p += baselen + 1;
      }
      memcpy(p, sym.data, sym.size);
      p += sym.size;
      if (_upb_DefPool_LookupSym(ctx->symtab, tmp, p - tmp, &v)) {
        break;
      }
      if (!remove_component(tmp, &baselen)) {
        upb_gfree(tmp);
        goto notfound;
      }
    }
    upb_gfree(tmp);
  }

  *type = _upb_DefType_Type(v);
  return _upb_DefType_Unpack(v, *type);

notfound:
  _upb_DefBuilder_Errf(ctx, "couldn't resolve name '" UPB_STRINGVIEW_FORMAT "'",
                       UPB_STRINGVIEW_ARGS(sym));
}

const void* _upb_DefBuilder_Resolve(upb_DefBuilder* ctx,
                                    const char* from_name_dbg, const char* base,
                                    upb_StringView sym, upb_deftype_t type) {
  upb_deftype_t found_type;
  const void* ret =
      _upb_DefBuilder_ResolveAny(ctx, from_name_dbg, base, sym, &found_type);
  if (ret && found_type != type) {
    _upb_DefBuilder_Errf(ctx,
                         "type mismatch when resolving %s: couldn't find "
                         "name " UPB_STRINGVIEW_FORMAT " with type=%d",
                         from_name_dbg, UPB_STRINGVIEW_ARGS(sym), (int)type);
  }
  return ret;
}

// Per ASCII this will lower-case a letter. If the result is a letter, the
// input was definitely a letter. If the output is not a letter, this may
// have transformed the character unpredictably.
static char upb_ascii_lower(char ch) { return ch | 0x20; }

// isalpha() etc. from <ctype.h> are locale-dependent, which we don't want.
static bool upb_isbetween(uint8_t c, uint8_t low, uint8_t high) {
  return low <= c && c <= high;
}

static bool upb_isletter(char c) {
  char lower = upb_ascii_lower(c);
  return upb_isbetween(lower, 'a', 'z') || c == '_';
}

static bool upb_isalphanum(char c) {
  return upb_isletter(c) || upb_isbetween(c, '0', '9');
}

static bool TryGetChar(const char** src, const char* end, char* ch) {
  if (*src == end) return false;
  *ch = **src;
  *src += 1;
  return true;
}

static int TryGetHexDigit(const char** src, const char* end) {
  char ch;
  if (!TryGetChar(src, end, &ch)) return -1;
  if ('0' <= ch && ch <= '9') {
    return ch - '0';
  }
  ch = upb_ascii_lower(ch);
  if ('a' <= ch && ch <= 'f') {
    return ch - 'a' + 0xa;
  }
  *src -= 1;  // Char wasn't actually a hex digit.
  return -1;
}

static char upb_DefBuilder_ParseHexEscape(upb_DefBuilder* ctx,
                                          const upb_FieldDef* f,
                                          const char** src, const char* end) {
  int hex_digit = TryGetHexDigit(src, end);
  if (hex_digit < 0) {
    _upb_DefBuilder_Errf(
        ctx, "\\x must be followed by at least one hex digit (field='%s')",
        upb_FieldDef_FullName(f));
    return 0;
  }
  unsigned int ret = hex_digit;
  while ((hex_digit = TryGetHexDigit(src, end)) >= 0) {
    ret = (ret << 4) | hex_digit;
  }
  if (ret > 0xff) {
    _upb_DefBuilder_Errf(ctx, "Value of hex escape in field %s exceeds 8 bits",
                         upb_FieldDef_FullName(f));
    return 0;
  }
  return ret;
}

static char TryGetOctalDigit(const char** src, const char* end) {
  char ch;
  if (!TryGetChar(src, end, &ch)) return -1;
  if ('0' <= ch && ch <= '7') {
    return ch - '0';
  }
  *src -= 1;  // Char wasn't actually an octal digit.
  return -1;
}

static char upb_DefBuilder_ParseOctalEscape(upb_DefBuilder* ctx,
                                            const upb_FieldDef* f,
                                            const char** src, const char* end) {
  char ch = 0;
  for (int i = 0; i < 3; i++) {
    char digit;
    if ((digit = TryGetOctalDigit(src, end)) >= 0) {
      ch = (ch << 3) | digit;
    }
  }
  return ch;
}

char _upb_DefBuilder_ParseEscape(upb_DefBuilder* ctx, const upb_FieldDef* f,
                                 const char** src, const char* end) {
  char ch;
  if (!TryGetChar(src, end, &ch)) {
    _upb_DefBuilder_Errf(ctx, "unterminated escape sequence in field %s",
                         upb_FieldDef_FullName(f));
    return 0;
  }
  switch (ch) {
    case 'a':
      return '\a';
    case 'b':
      return '\b';
    case 'f':
      return '\f';
    case 'n':
      return '\n';
    case 'r':
      return '\r';
    case 't':
      return '\t';
    case 'v':
      return '\v';
    case '\\':
      return '\\';
    case '\'':
      return '\'';
    case '\"':
      return '\"';
    case '?':
      return '\?';
    case 'x':
    case 'X':
      return upb_DefBuilder_ParseHexEscape(ctx, f, src, end);
    case '0':
    case '1':
    case '2':
    case '3':
    case '4':
    case '5':
    case '6':
    case '7':
      *src -= 1;
      return upb_DefBuilder_ParseOctalEscape(ctx, f, src, end);
  }
  _upb_DefBuilder_Errf(ctx, "Unknown escape sequence: \\%c", ch);
}

void _upb_DefBuilder_CheckIdentSlow(upb_DefBuilder* ctx, upb_StringView name,
                                    bool full) {
  const char* str = name.data;
  const size_t len = name.size;
  bool start = true;
  for (size_t i = 0; i < len; i++) {
    const char c = str[i];
    if (c == '.') {
      if (start || !full) {
        _upb_DefBuilder_Errf(
            ctx, "invalid name: unexpected '.' (" UPB_STRINGVIEW_FORMAT ")",
            UPB_STRINGVIEW_ARGS(name));
      }
      start = true;
    } else if (start) {
      if (!upb_isletter(c)) {
        _upb_DefBuilder_Errf(ctx,
                             "invalid name: path components must start with a "
                             "letter (" UPB_STRINGVIEW_FORMAT ")",
                             UPB_STRINGVIEW_ARGS(name));
      }
      start = false;
    } else if (!upb_isalphanum(c)) {
      _upb_DefBuilder_Errf(
          ctx,
          "invalid name: non-alphanumeric character (" UPB_STRINGVIEW_FORMAT
          ")",
          UPB_STRINGVIEW_ARGS(name));
    }
  }
  if (start) {
    _upb_DefBuilder_Errf(ctx,
                         "invalid name: empty part (" UPB_STRINGVIEW_FORMAT ")",
                         UPB_STRINGVIEW_ARGS(name));
  }

  // We should never reach this point.
  UPB_ASSERT(false);
}

upb_StringView _upb_DefBuilder_MakeKey(upb_DefBuilder* ctx,
                                       const google_protobuf_FeatureSet* parent,
                                       upb_StringView key) {
  size_t need = key.size + sizeof(void*);
  if (ctx->tmp_buf_size < need) {
    ctx->tmp_buf_size = UPB_MAX(64, upb_RoundUpToPowerOfTwo(need));
    ctx->tmp_buf = upb_Arena_Malloc(ctx->tmp_arena, ctx->tmp_buf_size);
    if (!ctx->tmp_buf) _upb_DefBuilder_OomErr(ctx);
  }

  memcpy(ctx->tmp_buf, &parent, sizeof(void*));
  memcpy(ctx->tmp_buf + sizeof(void*), key.data, key.size);
  return upb_StringView_FromDataAndSize(ctx->tmp_buf, need);
}

bool _upb_DefBuilder_GetOrCreateFeatureSet(upb_DefBuilder* ctx,
                                           const google_protobuf_FeatureSet* parent,
                                           upb_StringView key,
                                           google_protobuf_FeatureSet** set) {
  upb_StringView k = _upb_DefBuilder_MakeKey(ctx, parent, key);
  upb_value v;
  if (upb_strtable_lookup2(&ctx->feature_cache, k.data, k.size, &v)) {
    *set = upb_value_getptr(v);
    return false;
  }

  *set = (google_protobuf_FeatureSet*)upb_Message_DeepClone(
      UPB_UPCAST(parent), UPB_DESC_MINITABLE(FeatureSet), ctx->arena);
  if (!*set) _upb_DefBuilder_OomErr(ctx);

  v = upb_value_ptr(*set);
  if (!upb_strtable_insert(&ctx->feature_cache, k.data, k.size, v,
                           ctx->tmp_arena)) {
    _upb_DefBuilder_OomErr(ctx);
  }

  return true;
}

const google_protobuf_FeatureSet* _upb_DefBuilder_DoResolveFeatures(
    upb_DefBuilder* ctx, const google_protobuf_FeatureSet* parent,
    const google_protobuf_FeatureSet* child, bool is_implicit) {
  assert(parent);
  if (!child) return parent;

  if (!is_implicit &&
      _upb_DefBuilder_IsLegacyEdition(upb_FileDef_Edition(ctx->file))) {
    _upb_DefBuilder_Errf(ctx, "Features can only be specified for editions");
  }

  google_protobuf_FeatureSet* resolved;
  size_t child_size;
  const char* child_bytes =
      google_protobuf_FeatureSet_serialize(child, ctx->tmp_arena, &child_size);
  if (!child_bytes) _upb_DefBuilder_OomErr(ctx);

  upb_StringView key = upb_StringView_FromDataAndSize(child_bytes, child_size);
  if (!_upb_DefBuilder_GetOrCreateFeatureSet(ctx, parent, key, &resolved)) {
    return resolved;
  }

  upb_DecodeStatus dec_status =
      upb_Decode(child_bytes, child_size, UPB_UPCAST(resolved),
                 UPB_DESC_MINITABLE(FeatureSet), NULL, 0, ctx->arena);
  if (dec_status != kUpb_DecodeStatus_Ok) _upb_DefBuilder_OomErr(ctx);

  return resolved;
}


#include <string.h>


// Must be last.

char* upb_strdup2(const char* s, size_t len, upb_Arena* a) {
  size_t n;
  char* p;

  // Prevent overflow errors.
  if (len == SIZE_MAX) return NULL;

  // Always null-terminate, even if binary data; but don't rely on the input to
  // have a null-terminating byte since it may be a raw binary buffer.
  n = len + 1;
  p = upb_Arena_Malloc(a, n);
  if (p) {
    if (len != 0) memcpy(p, s, len);
    p[len] = 0;
  }
  return p;
}


#include <stdint.h>
#include <string.h>


// Must be last.

bool upb_Message_HasFieldByDef(const upb_Message* msg, const upb_FieldDef* f) {
  const upb_MiniTableField* m_f = upb_FieldDef_MiniTable(f);
  UPB_ASSERT(upb_FieldDef_HasPresence(f));

  if (upb_MiniTableField_IsExtension(m_f)) {
    return upb_Message_HasExtension(msg, (const upb_MiniTableExtension*)m_f);
  } else {
    return upb_Message_HasBaseField(msg, m_f);
  }
}

const upb_FieldDef* upb_Message_WhichOneofByDef(const upb_Message* msg,
                                                const upb_OneofDef* o) {
  const upb_FieldDef* f = upb_OneofDef_Field(o, 0);
  if (upb_OneofDef_IsSynthetic(o)) {
    UPB_ASSERT(upb_OneofDef_FieldCount(o) == 1);
    return upb_Message_HasFieldByDef(msg, f) ? f : NULL;
  } else {
    const upb_MiniTableField* field = upb_FieldDef_MiniTable(f);
    uint32_t oneof_case = upb_Message_WhichOneofFieldNumber(msg, field);
    f = oneof_case ? upb_OneofDef_LookupNumber(o, oneof_case) : NULL;
    UPB_ASSERT((f != NULL) == (oneof_case != 0));
    return f;
  }
}

upb_MessageValue upb_Message_GetFieldByDef(const upb_Message* msg,
                                           const upb_FieldDef* f) {
  upb_MessageValue default_val = upb_FieldDef_Default(f);
  return upb_Message_GetField(msg, upb_FieldDef_MiniTable(f), default_val);
}

upb_MutableMessageValue upb_Message_Mutable(upb_Message* msg,
                                            const upb_FieldDef* f,
                                            upb_Arena* a) {
  UPB_ASSERT(!upb_Message_IsFrozen(msg));
  UPB_ASSERT(upb_FieldDef_IsSubMessage(f) || upb_FieldDef_IsRepeated(f));
  if (upb_FieldDef_HasPresence(f) && !upb_Message_HasFieldByDef(msg, f)) {
    // We need to skip the upb_Message_GetFieldByDef() call in this case.
    goto make;
  }

  upb_MessageValue val = upb_Message_GetFieldByDef(msg, f);
  if (val.array_val) {
    return (upb_MutableMessageValue){.array = (upb_Array*)val.array_val};
  }

  upb_MutableMessageValue ret;
make:
  if (!a) return (upb_MutableMessageValue){.array = NULL};
  if (upb_FieldDef_IsMap(f)) {
    const upb_MessageDef* entry = upb_FieldDef_MessageSubDef(f);
    const upb_FieldDef* key =
        upb_MessageDef_FindFieldByNumber(entry, kUpb_MapEntry_KeyFieldNumber);
    const upb_FieldDef* value =
        upb_MessageDef_FindFieldByNumber(entry, kUpb_MapEntry_ValueFieldNumber);
    ret.map =
        upb_Map_New(a, upb_FieldDef_CType(key), upb_FieldDef_CType(value));
  } else if (upb_FieldDef_IsRepeated(f)) {
    ret.array = upb_Array_New(a, upb_FieldDef_CType(f));
  } else {
    UPB_ASSERT(upb_FieldDef_IsSubMessage(f));
    const upb_MessageDef* m = upb_FieldDef_MessageSubDef(f);
    ret.msg = upb_Message_New(upb_MessageDef_MiniTable(m), a);
  }

  val.array_val = ret.array;
  upb_Message_SetFieldByDef(msg, f, val, a);

  return ret;
}

bool upb_Message_SetFieldByDef(upb_Message* msg, const upb_FieldDef* f,
                               upb_MessageValue val, upb_Arena* a) {
  UPB_ASSERT(!upb_Message_IsFrozen(msg));
  const upb_MiniTableField* m_f = upb_FieldDef_MiniTable(f);

  if (upb_MiniTableField_IsExtension(m_f)) {
    return upb_Message_SetExtension(msg, (const upb_MiniTableExtension*)m_f,
                                    &val, a);
  } else {
    upb_Message_SetBaseField(msg, m_f, &val);
    return true;
  }
}

void upb_Message_ClearFieldByDef(upb_Message* msg, const upb_FieldDef* f) {
  UPB_ASSERT(!upb_Message_IsFrozen(msg));
  const upb_MiniTableField* m_f = upb_FieldDef_MiniTable(f);

  if (upb_MiniTableField_IsExtension(m_f)) {
    upb_Message_ClearExtension(msg, (const upb_MiniTableExtension*)m_f);
  } else {
    upb_Message_ClearBaseField(msg, m_f);
  }
}

void upb_Message_ClearByDef(upb_Message* msg, const upb_MessageDef* m) {
  UPB_ASSERT(!upb_Message_IsFrozen(msg));
  upb_Message_Clear(msg, upb_MessageDef_MiniTable(m));
}

bool upb_Message_Next(const upb_Message* msg, const upb_MessageDef* m,
                      const upb_DefPool* ext_pool, const upb_FieldDef** out_f,
                      upb_MessageValue* out_val, size_t* iter) {
  const upb_MiniTable* mt = upb_MessageDef_MiniTable(m);
  size_t i = *iter;
  size_t n = upb_MiniTable_FieldCount(mt);
  upb_MessageValue zero = upb_MessageValue_Zero();
  UPB_UNUSED(ext_pool);

  // Iterate over normal fields, returning the first one that is set.
  while (++i < n) {
    const upb_MiniTableField* field = upb_MiniTable_GetFieldByIndex(mt, i);
    upb_MessageValue val = upb_Message_GetField(msg, field, zero);

    // Skip field if unset or empty.
    if (upb_MiniTableField_HasPresence(field)) {
      if (!upb_Message_HasBaseField(msg, field)) continue;
    } else {
      switch (UPB_PRIVATE(_upb_MiniTableField_Mode)(field)) {
        case kUpb_FieldMode_Map:
          if (!val.map_val || upb_Map_Size(val.map_val) == 0) continue;
          break;
        case kUpb_FieldMode_Array:
          if (!val.array_val || upb_Array_Size(val.array_val) == 0) continue;
          break;
        case kUpb_FieldMode_Scalar:
          if (UPB_PRIVATE(_upb_MiniTableField_DataIsZero)(field, &val))
            continue;
          break;
      }
    }

    *out_val = val;
    *out_f =
        upb_MessageDef_FindFieldByNumber(m, upb_MiniTableField_Number(field));
    *iter = i;
    return true;
  }

  if (ext_pool) {
    upb_Message_Internal* in = UPB_PRIVATE(_upb_Message_GetInternal)(msg);
    if (!in) return false;

    for (; (i - n) < in->size; i++) {
      upb_TaggedAuxPtr tagged_ptr = in->aux_data[i - n];
      if (upb_TaggedAuxPtr_IsExtension(tagged_ptr)) {
        const upb_Extension* ext = upb_TaggedAuxPtr_Extension(tagged_ptr);
        memcpy(out_val, &ext->data, sizeof(*out_val));
        *out_f = upb_DefPool_FindExtensionByMiniTable(ext_pool, ext->ext);
        *iter = i;
        return true;
      }
    }
  }

  *iter = i;
  return false;
}

bool _upb_Message_DiscardUnknown(upb_Message* msg, const upb_MessageDef* m,
                                 const upb_DefPool* ext_pool, int depth) {
  UPB_ASSERT(!upb_Message_IsFrozen(msg));
  size_t iter = kUpb_Message_Begin;
  const upb_FieldDef* f;
  upb_MessageValue val;
  bool ret = true;

  if (--depth == 0) return false;

  _upb_Message_DiscardUnknown_shallow(msg);

  while (upb_Message_Next(msg, m, ext_pool, &f, &val, &iter)) {
    const upb_MessageDef* subm = upb_FieldDef_MessageSubDef(f);
    if (!subm) continue;
    if (upb_FieldDef_IsMap(f)) {
      const upb_FieldDef* val_f = upb_MessageDef_FindFieldByNumber(subm, 2);
      const upb_MessageDef* val_m = upb_FieldDef_MessageSubDef(val_f);
      upb_Map* map = (upb_Map*)val.map_val;
      size_t iter = kUpb_Map_Begin;

      if (!val_m) continue;

      upb_MessageValue map_key, map_val;
      while (upb_Map_Next(map, &map_key, &map_val, &iter)) {
        if (!_upb_Message_DiscardUnknown((upb_Message*)map_val.msg_val, val_m,
                                         ext_pool, depth)) {
          ret = false;
        }
      }
    } else if (upb_FieldDef_IsRepeated(f)) {
      const upb_Array* arr = val.array_val;
      size_t i, n = upb_Array_Size(arr);
      for (i = 0; i < n; i++) {
        upb_MessageValue elem = upb_Array_Get(arr, i);
        if (!_upb_Message_DiscardUnknown((upb_Message*)elem.msg_val, subm,
                                         ext_pool, depth)) {
          ret = false;
        }
      }
    } else {
      if (!_upb_Message_DiscardUnknown((upb_Message*)val.msg_val, subm,
                                       ext_pool, depth)) {
        ret = false;
      }
    }
  }

  return ret;
}

bool upb_Message_DiscardUnknown(upb_Message* msg, const upb_MessageDef* m,
                                const upb_DefPool* ext_pool, int maxdepth) {
  return _upb_Message_DiscardUnknown(msg, m, ext_pool, maxdepth);
}


#include <stddef.h>
#include <stdint.h>
#include <string.h>


// Must be last.

struct upb_MessageDef {
  UPB_ALIGN_AS(8) const google_protobuf_MessageOptions* opts;
  const google_protobuf_FeatureSet* resolved_features;
  const upb_MiniTable* layout;
  const upb_FileDef* file;
  const upb_MessageDef* containing_type;
  const char* full_name;

  // Tables for looking up fields by number and name.
  upb_inttable itof;
  upb_strtable ntof;

  // Looking up fields by json name.
  upb_strtable jtof;

  /* All nested defs.
   * MEM: We could save some space here by putting nested defs in a contiguous
   * region and calculating counts from offsets or vice-versa. */
  const upb_FieldDef* fields;
  const upb_OneofDef* oneofs;
  const upb_ExtensionRange* ext_ranges;
  const upb_StringView* res_names;
  const upb_MessageDef* nested_msgs;
  const upb_MessageReservedRange* res_ranges;
  const upb_EnumDef* nested_enums;
  const upb_FieldDef* nested_exts;

  // TODO: These counters don't need anywhere near 32 bits.
  int field_count;
  int real_oneof_count;
  int oneof_count;
  int ext_range_count;
  int res_range_count;
  int res_name_count;
  int nested_msg_count;
  int nested_enum_count;
  int nested_ext_count;
  bool in_message_set;
  bool is_sorted;
  upb_WellKnown well_known_type;
  google_protobuf_SymbolVisibility visibility;
};

static void assign_msg_wellknowntype(upb_MessageDef* m) {
  const char* name = m->full_name;
  if (name == NULL) {
    m->well_known_type = kUpb_WellKnown_Unspecified;
    return;
  }
  if (!strcmp(name, "google.protobuf.Any")) {
    m->well_known_type = kUpb_WellKnown_Any;
  } else if (!strcmp(name, "google.protobuf.FieldMask")) {
    m->well_known_type = kUpb_WellKnown_FieldMask;
  } else if (!strcmp(name, "google.protobuf.Duration")) {
    m->well_known_type = kUpb_WellKnown_Duration;
  } else if (!strcmp(name, "google.protobuf.Timestamp")) {
    m->well_known_type = kUpb_WellKnown_Timestamp;
  } else if (!strcmp(name, "google.protobuf.DoubleValue")) {
    m->well_known_type = kUpb_WellKnown_DoubleValue;
  } else if (!strcmp(name, "google.protobuf.FloatValue")) {
    m->well_known_type = kUpb_WellKnown_FloatValue;
  } else if (!strcmp(name, "google.protobuf.Int64Value")) {
    m->well_known_type = kUpb_WellKnown_Int64Value;
  } else if (!strcmp(name, "google.protobuf.UInt64Value")) {
    m->well_known_type = kUpb_WellKnown_UInt64Value;
  } else if (!strcmp(name, "google.protobuf.Int32Value")) {
    m->well_known_type = kUpb_WellKnown_Int32Value;
  } else if (!strcmp(name, "google.protobuf.UInt32Value")) {
    m->well_known_type = kUpb_WellKnown_UInt32Value;
  } else if (!strcmp(name, "google.protobuf.BoolValue")) {
    m->well_known_type = kUpb_WellKnown_BoolValue;
  } else if (!strcmp(name, "google.protobuf.StringValue")) {
    m->well_known_type = kUpb_WellKnown_StringValue;
  } else if (!strcmp(name, "google.protobuf.BytesValue")) {
    m->well_known_type = kUpb_WellKnown_BytesValue;
  } else if (!strcmp(name, "google.protobuf.Value")) {
    m->well_known_type = kUpb_WellKnown_Value;
  } else if (!strcmp(name, "google.protobuf.ListValue")) {
    m->well_known_type = kUpb_WellKnown_ListValue;
  } else if (!strcmp(name, "google.protobuf.Struct")) {
    m->well_known_type = kUpb_WellKnown_Struct;
  } else {
    m->well_known_type = kUpb_WellKnown_Unspecified;
  }
}

upb_MessageDef* _upb_MessageDef_At(const upb_MessageDef* m, int i) {
  return (upb_MessageDef*)&m[i];
}

bool _upb_MessageDef_IsValidExtensionNumber(const upb_MessageDef* m, int n) {
  for (int i = 0; i < m->ext_range_count; i++) {
    const upb_ExtensionRange* r = upb_MessageDef_ExtensionRange(m, i);
    if (upb_ExtensionRange_Start(r) <= n && n < upb_ExtensionRange_End(r)) {
      return true;
    }
  }
  return false;
}

const google_protobuf_MessageOptions* upb_MessageDef_Options(const upb_MessageDef* m) {
  return m->opts;
}

bool upb_MessageDef_HasOptions(const upb_MessageDef* m) {
  return m->opts != (void*)kUpbDefOptDefault;
}

const google_protobuf_FeatureSet* upb_MessageDef_ResolvedFeatures(
    const upb_MessageDef* m) {
  return m->resolved_features;
}

const char* upb_MessageDef_FullName(const upb_MessageDef* m) {
  return m->full_name;
}

const upb_FileDef* upb_MessageDef_File(const upb_MessageDef* m) {
  return m->file;
}

const upb_MessageDef* upb_MessageDef_ContainingType(const upb_MessageDef* m) {
  return m->containing_type;
}

const char* upb_MessageDef_Name(const upb_MessageDef* m) {
  return _upb_DefBuilder_FullToShort(m->full_name);
}

const upb_FieldDef* upb_MessageDef_FindFieldByNumber(const upb_MessageDef* m,
                                                     uint32_t i) {
  upb_value val;
  return upb_inttable_lookup(&m->itof, i, &val) ? upb_value_getconstptr(val)
                                                : NULL;
}

const upb_FieldDef* upb_MessageDef_FindFieldByNameWithSize(
    const upb_MessageDef* m, const char* name, size_t size) {
  upb_value val;

  if (!upb_strtable_lookup2(&m->ntof, name, size, &val)) {
    return NULL;
  }

  return _upb_DefType_Unpack(val, UPB_DEFTYPE_FIELD);
}

const upb_OneofDef* upb_MessageDef_FindOneofByNameWithSize(
    const upb_MessageDef* m, const char* name, size_t size) {
  upb_value val;

  if (!upb_strtable_lookup2(&m->ntof, name, size, &val)) {
    return NULL;
  }

  return _upb_DefType_Unpack(val, UPB_DEFTYPE_ONEOF);
}

bool _upb_MessageDef_Insert(upb_MessageDef* m, const char* name, size_t len,
                            upb_value v, upb_Arena* a) {
  return upb_strtable_insert(&m->ntof, name, len, v, a);
}

bool upb_MessageDef_FindByNameWithSize(const upb_MessageDef* m,
                                       const char* name, size_t len,
                                       const upb_FieldDef** out_f,
                                       const upb_OneofDef** out_o) {
  upb_value val;

  if (!upb_strtable_lookup2(&m->ntof, name, len, &val)) {
    return false;
  }

  const upb_FieldDef* f = _upb_DefType_Unpack(val, UPB_DEFTYPE_FIELD);
  const upb_OneofDef* o = _upb_DefType_Unpack(val, UPB_DEFTYPE_ONEOF);
  if (out_f) *out_f = f;
  if (out_o) *out_o = o;
  return f || o; /* False if this was a JSON name. */
}

const upb_FieldDef* upb_MessageDef_FindByJsonNameWithSize(
    const upb_MessageDef* m, const char* name, size_t size) {
  upb_value val;

  if (upb_strtable_lookup2(&m->jtof, name, size, &val)) {
    return upb_value_getconstptr(val);
  }

  if (!upb_strtable_lookup2(&m->ntof, name, size, &val)) {
    return NULL;
  }

  return _upb_DefType_Unpack(val, UPB_DEFTYPE_FIELD);
}

int upb_MessageDef_ExtensionRangeCount(const upb_MessageDef* m) {
  return m->ext_range_count;
}

int upb_MessageDef_ReservedRangeCount(const upb_MessageDef* m) {
  return m->res_range_count;
}

int upb_MessageDef_ReservedNameCount(const upb_MessageDef* m) {
  return m->res_name_count;
}

int upb_MessageDef_FieldCount(const upb_MessageDef* m) {
  return m->field_count;
}

int upb_MessageDef_OneofCount(const upb_MessageDef* m) {
  return m->oneof_count;
}

int upb_MessageDef_RealOneofCount(const upb_MessageDef* m) {
  return m->real_oneof_count;
}

int upb_MessageDef_NestedMessageCount(const upb_MessageDef* m) {
  return m->nested_msg_count;
}

int upb_MessageDef_NestedEnumCount(const upb_MessageDef* m) {
  return m->nested_enum_count;
}

int upb_MessageDef_NestedExtensionCount(const upb_MessageDef* m) {
  return m->nested_ext_count;
}

const upb_MiniTable* upb_MessageDef_MiniTable(const upb_MessageDef* m) {
  return m->layout;
}

const upb_ExtensionRange* upb_MessageDef_ExtensionRange(const upb_MessageDef* m,
                                                        int i) {
  UPB_ASSERT(0 <= i && i < m->ext_range_count);
  return _upb_ExtensionRange_At(m->ext_ranges, i);
}

const upb_MessageReservedRange* upb_MessageDef_ReservedRange(
    const upb_MessageDef* m, int i) {
  UPB_ASSERT(0 <= i && i < m->res_range_count);
  return _upb_MessageReservedRange_At(m->res_ranges, i);
}

upb_StringView upb_MessageDef_ReservedName(const upb_MessageDef* m, int i) {
  UPB_ASSERT(0 <= i && i < m->res_name_count);
  return m->res_names[i];
}

const upb_FieldDef* upb_MessageDef_Field(const upb_MessageDef* m, int i) {
  UPB_ASSERT(0 <= i && i < m->field_count);
  return _upb_FieldDef_At(m->fields, i);
}

const upb_OneofDef* upb_MessageDef_Oneof(const upb_MessageDef* m, int i) {
  UPB_ASSERT(0 <= i && i < m->oneof_count);
  return _upb_OneofDef_At(m->oneofs, i);
}

const upb_MessageDef* upb_MessageDef_NestedMessage(const upb_MessageDef* m,
                                                   int i) {
  UPB_ASSERT(0 <= i && i < m->nested_msg_count);
  return &m->nested_msgs[i];
}

const upb_EnumDef* upb_MessageDef_NestedEnum(const upb_MessageDef* m, int i) {
  UPB_ASSERT(0 <= i && i < m->nested_enum_count);
  return _upb_EnumDef_At(m->nested_enums, i);
}

const upb_FieldDef* upb_MessageDef_NestedExtension(const upb_MessageDef* m,
                                                   int i) {
  UPB_ASSERT(0 <= i && i < m->nested_ext_count);
  return _upb_FieldDef_At(m->nested_exts, i);
}

upb_WellKnown upb_MessageDef_WellKnownType(const upb_MessageDef* m) {
  return m->well_known_type;
}

UPB_API google_protobuf_SymbolVisibility
upb_MessageDef_Visibility(const upb_MessageDef* m) {
  return m->visibility;
}

bool _upb_MessageDef_InMessageSet(const upb_MessageDef* m) {
  return m->in_message_set;
}

const upb_FieldDef* upb_MessageDef_FindFieldByName(const upb_MessageDef* m,
                                                   const char* name) {
  return upb_MessageDef_FindFieldByNameWithSize(m, name, strlen(name));
}

const upb_OneofDef* upb_MessageDef_FindOneofByName(const upb_MessageDef* m,
                                                   const char* name) {
  return upb_MessageDef_FindOneofByNameWithSize(m, name, strlen(name));
}

bool upb_MessageDef_IsMapEntry(const upb_MessageDef* m) {
  return google_protobuf_MessageOptions_map_entry(m->opts);
}

bool upb_MessageDef_IsMessageSet(const upb_MessageDef* m) {
  return google_protobuf_MessageOptions_message_set_wire_format(m->opts);
}

static upb_MiniTable* _upb_MessageDef_MakeMiniTable(upb_DefBuilder* ctx,
                                                    const upb_MessageDef* m) {
  upb_StringView desc;
  // Note: this will assign layout_index for fields, so upb_FieldDef_MiniTable()
  // is safe to call only after this call.
  bool ok = upb_MessageDef_MiniDescriptorEncode(m, ctx->tmp_arena, &desc);
  if (!ok) _upb_DefBuilder_OomErr(ctx);

  void** scratch_data = _upb_DefPool_ScratchData(ctx->symtab);
  size_t* scratch_size = _upb_DefPool_ScratchSize(ctx->symtab);
  upb_MiniTable* ret = upb_MiniTable_BuildWithBuf(
      desc.data, desc.size, ctx->platform, ctx->arena, scratch_data,
      scratch_size, ctx->status);
  if (!ret) _upb_DefBuilder_FailJmp(ctx);

  return ret;
}

void _upb_MessageDef_Resolve(upb_DefBuilder* ctx, upb_MessageDef* m) {
  for (int i = 0; i < m->field_count; i++) {
    upb_FieldDef* f = (upb_FieldDef*)upb_MessageDef_Field(m, i);
    _upb_FieldDef_Resolve(ctx, m->full_name, f);
  }

  m->in_message_set = false;
  for (int i = 0; i < upb_MessageDef_NestedExtensionCount(m); i++) {
    upb_FieldDef* ext = (upb_FieldDef*)upb_MessageDef_NestedExtension(m, i);
    _upb_FieldDef_Resolve(ctx, m->full_name, ext);
    if (upb_FieldDef_Type(ext) == kUpb_FieldType_Message &&
        upb_FieldDef_Label(ext) == kUpb_Label_Optional &&
        upb_FieldDef_MessageSubDef(ext) == m &&
        google_protobuf_MessageOptions_message_set_wire_format(
            upb_MessageDef_Options(upb_FieldDef_ContainingType(ext)))) {
      m->in_message_set = true;
    }
  }

  for (int i = 0; i < upb_MessageDef_NestedMessageCount(m); i++) {
    upb_MessageDef* n = (upb_MessageDef*)upb_MessageDef_NestedMessage(m, i);
    _upb_MessageDef_Resolve(ctx, n);
  }
}

void _upb_MessageDef_InsertField(upb_DefBuilder* ctx, upb_MessageDef* m,
                                 const upb_FieldDef* f) {
  const int32_t field_number = upb_FieldDef_Number(f);

  if (field_number <= 0 || field_number > kUpb_MaxFieldNumber) {
    _upb_DefBuilder_Errf(ctx, "invalid field number (%u)", field_number);
  }

  const char* json_name = upb_FieldDef_JsonName(f);
  const char* shortname = upb_FieldDef_Name(f);
  const size_t shortnamelen = strlen(shortname);

  upb_value v = upb_value_constptr(f);

  upb_value existing_v;
  if (upb_strtable_lookup(&m->ntof, shortname, &existing_v)) {
    _upb_DefBuilder_Errf(ctx, "duplicate field name (%s)", shortname);
  }

  const upb_value field_v = _upb_DefType_Pack(f, UPB_DEFTYPE_FIELD);
  bool ok =
      _upb_MessageDef_Insert(m, shortname, shortnamelen, field_v, ctx->arena);
  if (!ok) _upb_DefBuilder_OomErr(ctx);

  bool skip_json_conflicts =
      google_protobuf_MessageOptions_deprecated_legacy_json_field_conflicts(
          upb_MessageDef_Options(m));
  if (!skip_json_conflicts && strcmp(shortname, json_name) != 0 &&
      google_protobuf_FeatureSet_json_format(m->resolved_features) ==
          google_protobuf_FeatureSet_ALLOW &&
      upb_strtable_lookup(&m->ntof, json_name, &v)) {
    _upb_DefBuilder_Errf(
        ctx, "duplicate json_name for (%s) with original field name (%s)",
        shortname, json_name);
  }

  if (upb_strtable_lookup(&m->jtof, json_name, &v)) {
    if (!skip_json_conflicts) {
      _upb_DefBuilder_Errf(ctx, "duplicate json_name (%s)", json_name);
    }
  } else {
    const size_t json_size = strlen(json_name);
    ok = upb_strtable_insert(&m->jtof, json_name, json_size,
                             upb_value_constptr(f), ctx->arena);
    if (!ok) _upb_DefBuilder_OomErr(ctx);
  }

  if (upb_inttable_lookup(&m->itof, field_number, NULL)) {
    _upb_DefBuilder_Errf(ctx, "duplicate field number (%u)", field_number);
  }

  ok = upb_inttable_insert(&m->itof, field_number, v, ctx->arena);
  if (!ok) _upb_DefBuilder_OomErr(ctx);
}

void _upb_MessageDef_CreateMiniTable(upb_DefBuilder* ctx, upb_MessageDef* m) {
  if (ctx->layout == NULL) {
    m->layout = _upb_MessageDef_MakeMiniTable(ctx, m);
  } else {
    m->layout = upb_MiniTableFile_Message(ctx->layout, ctx->msg_count++);
    UPB_ASSERT(m->field_count == upb_MiniTable_FieldCount(m->layout));

    // We don't need the result of this call, but it will assign layout_index
    // for all the fields in O(n lg n) time.
    _upb_FieldDefs_Sorted(m->fields, m->field_count, ctx->tmp_arena);
  }

  for (int i = 0; i < m->nested_msg_count; i++) {
    upb_MessageDef* nested =
        (upb_MessageDef*)upb_MessageDef_NestedMessage(m, i);
    _upb_MessageDef_CreateMiniTable(ctx, nested);
  }
}

void _upb_MessageDef_LinkMiniTable(upb_DefBuilder* ctx,
                                   const upb_MessageDef* m) {
  for (int i = 0; i < upb_MessageDef_NestedExtensionCount(m); i++) {
    const upb_FieldDef* ext = upb_MessageDef_NestedExtension(m, i);
    _upb_FieldDef_BuildMiniTableExtension(ctx, ext);
  }

  for (int i = 0; i < m->nested_msg_count; i++) {
    _upb_MessageDef_LinkMiniTable(ctx, upb_MessageDef_NestedMessage(m, i));
  }

  if (ctx->layout || ctx->platform != kUpb_MiniTablePlatform_Native) return;

  for (int i = 0; i < m->field_count; i++) {
    const upb_FieldDef* f = upb_MessageDef_Field(m, i);
    const upb_MessageDef* sub_m = upb_FieldDef_MessageSubDef(f);
    const upb_EnumDef* sub_e = upb_FieldDef_EnumSubDef(f);
    const int layout_index = _upb_FieldDef_LayoutIndex(f);
    upb_MiniTable* mt = (upb_MiniTable*)upb_MessageDef_MiniTable(m);

    UPB_ASSERT(layout_index < m->field_count);
    upb_MiniTableField* mt_f =
        (upb_MiniTableField*)&m->layout->UPB_PRIVATE(fields)[layout_index];
    if (sub_m) {
      UPB_ASSERT(mt_f);
      UPB_ASSERT(sub_m->layout);
      if (UPB_UNLIKELY(!upb_MiniTable_SetSubMessage(mt, mt_f, sub_m->layout))) {
        _upb_DefBuilder_Errf(ctx, "invalid submsg for (%s)", m->full_name);
      }
    } else if (_upb_FieldDef_IsClosedEnum(f)) {
      const upb_MiniTableEnum* mt_e = _upb_EnumDef_MiniTable(sub_e);
      if (UPB_UNLIKELY(!upb_MiniTable_SetSubEnum(mt, mt_f, mt_e))) {
        _upb_DefBuilder_Errf(ctx, "invalid subenum for (%s)", m->full_name);
      }
    }
  }

#ifndef NDEBUG
  for (int i = 0; i < m->field_count; i++) {
    const upb_FieldDef* f = upb_MessageDef_Field(m, i);
    const int layout_index = _upb_FieldDef_LayoutIndex(f);
    UPB_ASSERT(layout_index < upb_MiniTable_FieldCount(m->layout));
    const upb_MiniTableField* mt_f =
        &m->layout->UPB_PRIVATE(fields)[layout_index];
    UPB_ASSERT(upb_FieldDef_Type(f) == upb_MiniTableField_Type(mt_f));
    UPB_ASSERT(upb_FieldDef_CType(f) == upb_MiniTableField_CType(mt_f));
    UPB_ASSERT(upb_FieldDef_HasPresence(f) ==
               upb_MiniTableField_HasPresence(mt_f));
  }
#endif
}

// Returns whether packable repeated fields in the message should be considered
// packed by default. This is used only for the purpose of encoding
// MiniDescriptors, so we just return true if there are more packed fields than
// unpacked. This optimizes for smaller MiniDescriptors.
static bool _upb_MessageDef_DefaultIsPacked(const upb_MessageDef* m) {
  int packed = 0;
  int unpacked = 0;
  for (int i = 0; i < m->field_count; i++) {
    const upb_FieldDef* f = upb_MessageDef_Field(m, i);
    if (_upb_FieldDef_IsPackable(f)) {
      if (upb_FieldDef_IsPacked(f)) {
        ++packed;
      } else {
        ++unpacked;
      }
    }
  }
  return packed > unpacked;
}

static bool _upb_MessageDef_ValidateUtf8(const upb_MessageDef* m) {
  bool has_string = false;
  for (int i = 0; i < m->field_count; i++) {
    const upb_FieldDef* f = upb_MessageDef_Field(m, i);
    // Old binaries do not recognize the field-level "FlipValidateUtf8" wire
    // modifier, so we do not actually have field-level control for old
    // binaries.  Given this, we judge that the better failure mode is to be
    // more lax than intended, rather than more strict.  To achieve this, we
    // only mark the message with the ValidateUtf8 modifier if *all* fields
    // validate UTF-8.
    if (!_upb_FieldDef_ValidateUtf8(f)) return false;
    if (upb_FieldDef_Type(f) == kUpb_FieldType_String) has_string = true;
  }
  return has_string;
}

static uint64_t _upb_MessageDef_Modifiers(const upb_MessageDef* m) {
  uint64_t out = 0;

  if (_upb_MessageDef_DefaultIsPacked(m)) {
    out |= kUpb_MessageModifier_DefaultIsPacked;
  }

  if (_upb_MessageDef_ValidateUtf8(m)) {
    out |= kUpb_MessageModifier_ValidateUtf8;
  }

  if (m->ext_range_count) {
    out |= kUpb_MessageModifier_IsExtendable;
  }

  return out;
}

static bool _upb_MessageDef_EncodeMap(upb_DescState* s, const upb_MessageDef* m,
                                      upb_Arena* a) {
  if (m->field_count != 2) return false;

  const upb_FieldDef* key_field = upb_MessageDef_Field(m, 0);
  const upb_FieldDef* val_field = upb_MessageDef_Field(m, 1);
  if (key_field == NULL || val_field == NULL) return false;

  UPB_ASSERT(_upb_FieldDef_LayoutIndex(key_field) == 0);
  UPB_ASSERT(_upb_FieldDef_LayoutIndex(val_field) == 1);

  s->ptr = upb_MtDataEncoder_EncodeMap(
      &s->e, s->ptr, upb_FieldDef_Type(key_field), upb_FieldDef_Type(val_field),
      _upb_FieldDef_Modifiers(key_field), _upb_FieldDef_Modifiers(val_field));
  return true;
}

static bool _upb_MessageDef_EncodeMessage(upb_DescState* s,
                                          const upb_MessageDef* m,
                                          upb_Arena* a) {
  const upb_FieldDef** sorted = NULL;
  if (!m->is_sorted) {
    sorted = _upb_FieldDefs_Sorted(m->fields, m->field_count, a);
    if (!sorted) return false;
  }

  s->ptr = upb_MtDataEncoder_StartMessage(&s->e, s->ptr,
                                          _upb_MessageDef_Modifiers(m));

  for (int i = 0; i < m->field_count; i++) {
    const upb_FieldDef* f = sorted ? sorted[i] : upb_MessageDef_Field(m, i);
    const upb_FieldType type = upb_FieldDef_Type(f);
    const int number = upb_FieldDef_Number(f);
    const uint64_t modifiers = _upb_FieldDef_Modifiers(f);

    if (!_upb_DescState_Grow(s, a)) return false;
    s->ptr = upb_MtDataEncoder_PutField(&s->e, s->ptr, type, number, modifiers);
  }

  for (int i = 0; i < m->real_oneof_count; i++) {
    if (!_upb_DescState_Grow(s, a)) return false;
    s->ptr = upb_MtDataEncoder_StartOneof(&s->e, s->ptr);

    const upb_OneofDef* o = upb_MessageDef_Oneof(m, i);
    const int field_count = upb_OneofDef_FieldCount(o);
    for (int j = 0; j < field_count; j++) {
      const int number = upb_FieldDef_Number(upb_OneofDef_Field(o, j));

      if (!_upb_DescState_Grow(s, a)) return false;
      s->ptr = upb_MtDataEncoder_PutOneofField(&s->e, s->ptr, number);
    }
  }

  return true;
}

static bool _upb_MessageDef_EncodeMessageSet(upb_DescState* s,
                                             const upb_MessageDef* m,
                                             upb_Arena* a) {
  s->ptr = upb_MtDataEncoder_EncodeMessageSet(&s->e, s->ptr);

  return true;
}

bool upb_MessageDef_MiniDescriptorEncode(const upb_MessageDef* m, upb_Arena* a,
                                         upb_StringView* out) {
  upb_DescState s;
  _upb_DescState_Init(&s);

  if (!_upb_DescState_Grow(&s, a)) return false;

  if (upb_MessageDef_IsMapEntry(m)) {
    if (!_upb_MessageDef_EncodeMap(&s, m, a)) return false;
  } else if (google_protobuf_MessageOptions_message_set_wire_format(m->opts)) {
    if (!_upb_MessageDef_EncodeMessageSet(&s, m, a)) return false;
  } else {
    if (!_upb_MessageDef_EncodeMessage(&s, m, a)) return false;
  }

  if (!_upb_DescState_Grow(&s, a)) return false;
  *s.ptr = '\0';

  out->data = s.buf;
  out->size = s.ptr - s.buf;
  return true;
}

static upb_StringView* _upb_ReservedNames_New(upb_DefBuilder* ctx, int n,
                                              const upb_StringView* protos) {
  upb_StringView* sv = UPB_DEFBUILDER_ALLOCARRAY(ctx, upb_StringView, n);
  for (int i = 0; i < n; i++) {
    sv[i].data =
        upb_strdup2(protos[i].data, protos[i].size, _upb_DefBuilder_Arena(ctx));
    sv[i].size = protos[i].size;
  }
  return sv;
}

static void create_msgdef(upb_DefBuilder* ctx, const char* prefix,
                          const google_protobuf_DescriptorProto* msg_proto,
                          const google_protobuf_FeatureSet* parent_features,
                          const upb_MessageDef* containing_type,
                          upb_MessageDef* m) {
  const google_protobuf_OneofDescriptorProto* const* oneofs;
  const google_protobuf_FieldDescriptorProto* const* fields;
  const google_protobuf_DescriptorProto_ExtensionRange* const* ext_ranges;
  const google_protobuf_DescriptorProto_ReservedRange* const* res_ranges;
  const upb_StringView* res_names;
  size_t n_oneof, n_field, n_enum, n_ext, n_msg;
  size_t n_ext_range, n_res_range, n_res_name;
  upb_StringView name;

  UPB_DEF_SET_OPTIONS(m->opts, DescriptorProto, MessageOptions, msg_proto);
  m->resolved_features = _upb_DefBuilder_ResolveFeatures(
      ctx, parent_features, google_protobuf_MessageOptions_features(m->opts));

  // Must happen before _upb_DefBuilder_Add()
  m->file = _upb_DefBuilder_File(ctx);

  m->containing_type = containing_type;
  m->is_sorted = true;

  name = google_protobuf_DescriptorProto_name(msg_proto);

  m->full_name = _upb_DefBuilder_MakeFullName(ctx, prefix, name);
  _upb_DefBuilder_Add(ctx, m->full_name, _upb_DefType_Pack(m, UPB_DEFTYPE_MSG));

  oneofs = google_protobuf_DescriptorProto_oneof_decl(msg_proto, &n_oneof);
  fields = google_protobuf_DescriptorProto_field(msg_proto, &n_field);
  ext_ranges = google_protobuf_DescriptorProto_extension_range(msg_proto, &n_ext_range);
  res_ranges = google_protobuf_DescriptorProto_reserved_range(msg_proto, &n_res_range);
  res_names = google_protobuf_DescriptorProto_reserved_name(msg_proto, &n_res_name);

  bool ok = upb_inttable_init(&m->itof, ctx->arena);
  if (!ok) _upb_DefBuilder_OomErr(ctx);

  ok = upb_strtable_init(&m->ntof, n_oneof + n_field, ctx->arena);
  if (!ok) _upb_DefBuilder_OomErr(ctx);

  ok = upb_strtable_init(&m->jtof, n_field, ctx->arena);
  if (!ok) _upb_DefBuilder_OomErr(ctx);

  m->oneof_count = n_oneof;
  m->oneofs = _upb_OneofDefs_New(ctx, n_oneof, oneofs, m->resolved_features, m);

  m->field_count = n_field;
  m->fields = _upb_FieldDefs_New(ctx, n_field, fields, m->resolved_features,
                                 m->full_name, m, &m->is_sorted);

  // Message Sets may not contain fields.
  if (UPB_UNLIKELY(google_protobuf_MessageOptions_message_set_wire_format(m->opts))) {
    if (UPB_UNLIKELY(n_field > 0)) {
      _upb_DefBuilder_Errf(ctx, "invalid message set (%s)", m->full_name);
    }
  }

  m->ext_range_count = n_ext_range;
  m->ext_ranges = _upb_ExtensionRanges_New(ctx, n_ext_range, ext_ranges,
                                           m->resolved_features, m);

  m->res_range_count = n_res_range;
  m->res_ranges =
      _upb_MessageReservedRanges_New(ctx, n_res_range, res_ranges, m);

  m->res_name_count = n_res_name;
  m->res_names = _upb_ReservedNames_New(ctx, n_res_name, res_names);

  const size_t synthetic_count = _upb_OneofDefs_Finalize(ctx, m);
  m->real_oneof_count = m->oneof_count - synthetic_count;

  assign_msg_wellknowntype(m);
  if (!upb_inttable_compact(&m->itof, ctx->arena)) _upb_DefBuilder_OomErr(ctx);

  const google_protobuf_EnumDescriptorProto* const* enums =
      google_protobuf_DescriptorProto_enum_type(msg_proto, &n_enum);
  m->nested_enum_count = n_enum;
  m->nested_enums =
      _upb_EnumDefs_New(ctx, n_enum, enums, m->resolved_features, m);

  const google_protobuf_FieldDescriptorProto* const* exts =
      google_protobuf_DescriptorProto_extension(msg_proto, &n_ext);
  m->nested_ext_count = n_ext;
  m->nested_exts = _upb_Extensions_New(ctx, n_ext, exts, m->resolved_features,
                                       m->full_name, m);

  const google_protobuf_DescriptorProto* const* msgs =
      google_protobuf_DescriptorProto_nested_type(msg_proto, &n_msg);
  m->nested_msg_count = n_msg;
  m->nested_msgs =
      _upb_MessageDefs_New(ctx, n_msg, msgs, m->resolved_features, m);

  m->visibility = google_protobuf_DescriptorProto_visibility(msg_proto);
}

// Allocate and initialize an array of |n| message defs.
upb_MessageDef* _upb_MessageDefs_New(
    upb_DefBuilder* ctx, int n, const google_protobuf_DescriptorProto* const* protos,
    const google_protobuf_FeatureSet* parent_features,
    const upb_MessageDef* containing_type) {
  _upb_DefType_CheckPadding(sizeof(upb_MessageDef));

  const char* name = containing_type ? containing_type->full_name
                                     : _upb_FileDef_RawPackage(ctx->file);

  upb_MessageDef* m = UPB_DEFBUILDER_ALLOCARRAY(ctx, upb_MessageDef, n);
  for (int i = 0; i < n; i++) {
    create_msgdef(ctx, name, protos[i], parent_features, containing_type,
                  &m[i]);
  }
  return m;
}

#include <stdint.h>


// Must be last.

struct upb_MessageReservedRange {
  int32_t start;
  int32_t end;
};

upb_MessageReservedRange* _upb_MessageReservedRange_At(
    const upb_MessageReservedRange* r, int i) {
  return (upb_MessageReservedRange*)&r[i];
}

int32_t upb_MessageReservedRange_Start(const upb_MessageReservedRange* r) {
  return r->start;
}
int32_t upb_MessageReservedRange_End(const upb_MessageReservedRange* r) {
  return r->end;
}

upb_MessageReservedRange* _upb_MessageReservedRanges_New(
    upb_DefBuilder* ctx, int n,
    const google_protobuf_DescriptorProto_ReservedRange* const* protos,
    const upb_MessageDef* m) {
  upb_MessageReservedRange* r =
      UPB_DEFBUILDER_ALLOCARRAY(ctx, upb_MessageReservedRange, n);

  for (int i = 0; i < n; i++) {
    const int32_t start = google_protobuf_DescriptorProto_ReservedRange_start(protos[i]);
    const int32_t end = google_protobuf_DescriptorProto_ReservedRange_end(protos[i]);
    const int32_t max = kUpb_MaxFieldNumber + 1;

    // A full validation would also check that each range is disjoint, and that
    // none of the fields overlap with the extension ranges, but we are just
    // sanity checking here.
    if (start < 1 || end <= start || end > max) {
      _upb_DefBuilder_Errf(ctx,
                           "Reserved range (%d, %d) is invalid, message=%s\n",
                           (int)start, (int)end, upb_MessageDef_FullName(m));
    }

    r[i].start = start;
    r[i].end = end;
  }

  return r;
}



// Must be last.

struct upb_MethodDef {
  const google_protobuf_MethodOptions* opts;
  const google_protobuf_FeatureSet* resolved_features;
  upb_ServiceDef* service;
  const char* full_name;
  const upb_MessageDef* input_type;
  const upb_MessageDef* output_type;
  int index;
  bool client_streaming;
  bool server_streaming;
};

upb_MethodDef* _upb_MethodDef_At(const upb_MethodDef* m, int i) {
  return (upb_MethodDef*)&m[i];
}

const upb_ServiceDef* upb_MethodDef_Service(const upb_MethodDef* m) {
  return m->service;
}

const google_protobuf_MethodOptions* upb_MethodDef_Options(const upb_MethodDef* m) {
  return m->opts;
}

bool upb_MethodDef_HasOptions(const upb_MethodDef* m) {
  return m->opts != (void*)kUpbDefOptDefault;
}

const google_protobuf_FeatureSet* upb_MethodDef_ResolvedFeatures(
    const upb_MethodDef* m) {
  return m->resolved_features;
}

const char* upb_MethodDef_FullName(const upb_MethodDef* m) {
  return m->full_name;
}

const char* upb_MethodDef_Name(const upb_MethodDef* m) {
  return _upb_DefBuilder_FullToShort(m->full_name);
}

int upb_MethodDef_Index(const upb_MethodDef* m) { return m->index; }

const upb_MessageDef* upb_MethodDef_InputType(const upb_MethodDef* m) {
  return m->input_type;
}

const upb_MessageDef* upb_MethodDef_OutputType(const upb_MethodDef* m) {
  return m->output_type;
}

bool upb_MethodDef_ClientStreaming(const upb_MethodDef* m) {
  return m->client_streaming;
}

bool upb_MethodDef_ServerStreaming(const upb_MethodDef* m) {
  return m->server_streaming;
}

static void create_method(upb_DefBuilder* ctx,
                          const google_protobuf_MethodDescriptorProto* method_proto,
                          const google_protobuf_FeatureSet* parent_features,
                          upb_ServiceDef* s, upb_MethodDef* m) {
  UPB_DEF_SET_OPTIONS(m->opts, MethodDescriptorProto, MethodOptions,
                      method_proto);
  m->resolved_features = _upb_DefBuilder_ResolveFeatures(
      ctx, parent_features, google_protobuf_MethodOptions_features(m->opts));

  upb_StringView name = google_protobuf_MethodDescriptorProto_name(method_proto);

  m->service = s;
  m->full_name =
      _upb_DefBuilder_MakeFullName(ctx, upb_ServiceDef_FullName(s), name);
  m->client_streaming =
      google_protobuf_MethodDescriptorProto_client_streaming(method_proto);
  m->server_streaming =
      google_protobuf_MethodDescriptorProto_server_streaming(method_proto);
  m->input_type = _upb_DefBuilder_Resolve(
      ctx, m->full_name, m->full_name,
      google_protobuf_MethodDescriptorProto_input_type(method_proto), UPB_DEFTYPE_MSG);
  m->output_type = _upb_DefBuilder_Resolve(
      ctx, m->full_name, m->full_name,
      google_protobuf_MethodDescriptorProto_output_type(method_proto), UPB_DEFTYPE_MSG);
  _upb_ServiceDef_InsertMethod(ctx, s, m);
}

// Allocate and initialize an array of |n| method defs belonging to |s|.
upb_MethodDef* _upb_MethodDefs_New(
    upb_DefBuilder* ctx, int n,
    const google_protobuf_MethodDescriptorProto* const* protos,
    const google_protobuf_FeatureSet* parent_features, upb_ServiceDef* s) {
  upb_MethodDef* m = UPB_DEFBUILDER_ALLOCARRAY(ctx, upb_MethodDef, n);
  for (int i = 0; i < n; i++) {
    create_method(ctx, protos[i], parent_features, s, &m[i]);
    m[i].index = i;
  }
  return m;
}


#include <stdint.h>
#include <stdlib.h>
#include <string.h>


// Must be last.

struct upb_OneofDef {
  UPB_ALIGN_AS(8) const google_protobuf_OneofOptions* opts;
  const google_protobuf_FeatureSet* resolved_features;
  const upb_MessageDef* parent;
  const char* full_name;
  int field_count;
  bool synthetic;
  const upb_FieldDef** fields;
  upb_strtable ntof;  // lookup a field by name
  upb_inttable itof;  // lookup a field by number (index)
};

upb_OneofDef* _upb_OneofDef_At(const upb_OneofDef* o, int i) {
  return (upb_OneofDef*)&o[i];
}

const google_protobuf_OneofOptions* upb_OneofDef_Options(const upb_OneofDef* o) {
  return o->opts;
}

bool upb_OneofDef_HasOptions(const upb_OneofDef* o) {
  return o->opts != (void*)kUpbDefOptDefault;
}

const google_protobuf_FeatureSet* upb_OneofDef_ResolvedFeatures(const upb_OneofDef* o) {
  return o->resolved_features;
}

const char* upb_OneofDef_FullName(const upb_OneofDef* o) {
  return o->full_name;
}

const char* upb_OneofDef_Name(const upb_OneofDef* o) {
  return _upb_DefBuilder_FullToShort(o->full_name);
}

const upb_MessageDef* upb_OneofDef_ContainingType(const upb_OneofDef* o) {
  return o->parent;
}

int upb_OneofDef_FieldCount(const upb_OneofDef* o) { return o->field_count; }

const upb_FieldDef* upb_OneofDef_Field(const upb_OneofDef* o, int i) {
  UPB_ASSERT(i < o->field_count);
  return o->fields[i];
}

int upb_OneofDef_numfields(const upb_OneofDef* o) { return o->field_count; }

uint32_t upb_OneofDef_Index(const upb_OneofDef* o) {
  // Compute index in our parent's array.
  return o - upb_MessageDef_Oneof(o->parent, 0);
}

bool upb_OneofDef_IsSynthetic(const upb_OneofDef* o) { return o->synthetic; }

const upb_FieldDef* upb_OneofDef_LookupNameWithSize(const upb_OneofDef* o,
                                                    const char* name,
                                                    size_t size) {
  upb_value val;
  return upb_strtable_lookup2(&o->ntof, name, size, &val)
             ? upb_value_getptr(val)
             : NULL;
}

const upb_FieldDef* upb_OneofDef_LookupName(const upb_OneofDef* o,
                                            const char* name) {
  return upb_OneofDef_LookupNameWithSize(o, name, strlen(name));
}

const upb_FieldDef* upb_OneofDef_LookupNumber(const upb_OneofDef* o,
                                              uint32_t num) {
  upb_value val;
  return upb_inttable_lookup(&o->itof, num, &val) ? upb_value_getptr(val)
                                                  : NULL;
}

void _upb_OneofDef_Insert(upb_DefBuilder* ctx, upb_OneofDef* o,
                          const upb_FieldDef* f, const char* name,
                          size_t size) {
  o->field_count++;
  if (_upb_FieldDef_IsProto3Optional(f)) o->synthetic = true;

  const int number = upb_FieldDef_Number(f);
  const upb_value v = upb_value_constptr(f);

  // TODO: This lookup is unfortunate because we also perform it when
  // inserting into the message's table. Unfortunately that step occurs after
  // this one and moving things around could be tricky so let's leave it for
  // a future refactoring.
  const bool number_exists = upb_inttable_lookup(&o->itof, number, NULL);
  if (UPB_UNLIKELY(number_exists)) {
    _upb_DefBuilder_Errf(ctx, "oneof fields have the same number (%d)", number);
  }

  // TODO: More redundant work happening here.
  const bool name_exists = upb_strtable_lookup2(&o->ntof, name, size, NULL);
  if (UPB_UNLIKELY(name_exists)) {
    _upb_DefBuilder_Errf(ctx, "oneof fields have the same name (%.*s)",
                         (int)size, name);
  }

  const bool ok = upb_inttable_insert(&o->itof, number, v, ctx->arena) &&
                  upb_strtable_insert(&o->ntof, name, size, v, ctx->arena);
  if (UPB_UNLIKELY(!ok)) {
    _upb_DefBuilder_OomErr(ctx);
  }
}

// Returns the synthetic count.
size_t _upb_OneofDefs_Finalize(upb_DefBuilder* ctx, upb_MessageDef* m) {
  int synthetic_count = 0;

  for (int i = 0; i < upb_MessageDef_OneofCount(m); i++) {
    upb_OneofDef* o = (upb_OneofDef*)upb_MessageDef_Oneof(m, i);

    if (o->synthetic && o->field_count != 1) {
      _upb_DefBuilder_Errf(ctx,
                           "Synthetic oneofs must have one field, not %d: %s",
                           o->field_count, upb_OneofDef_Name(o));
    }

    if (o->synthetic) {
      synthetic_count++;
    } else if (synthetic_count != 0) {
      _upb_DefBuilder_Errf(
          ctx, "Synthetic oneofs must be after all other oneofs: %s",
          upb_OneofDef_Name(o));
    }

    o->fields =
        UPB_DEFBUILDER_ALLOCARRAY(ctx, const upb_FieldDef*, o->field_count);
    o->field_count = 0;
  }

  for (int i = 0; i < upb_MessageDef_FieldCount(m); i++) {
    const upb_FieldDef* f = upb_MessageDef_Field(m, i);
    upb_OneofDef* o = (upb_OneofDef*)upb_FieldDef_ContainingOneof(f);
    if (o) {
      o->fields[o->field_count++] = f;
    }
  }

  return synthetic_count;
}

static void create_oneofdef(upb_DefBuilder* ctx, upb_MessageDef* m,
                            const google_protobuf_OneofDescriptorProto* oneof_proto,
                            const google_protobuf_FeatureSet* parent_features,
                            const upb_OneofDef* _o) {
  upb_OneofDef* o = (upb_OneofDef*)_o;

  UPB_DEF_SET_OPTIONS(o->opts, OneofDescriptorProto, OneofOptions, oneof_proto);
  o->resolved_features = _upb_DefBuilder_ResolveFeatures(
      ctx, parent_features, google_protobuf_OneofOptions_features(o->opts));

  upb_StringView name = google_protobuf_OneofDescriptorProto_name(oneof_proto);

  o->parent = m;
  o->full_name =
      _upb_DefBuilder_MakeFullName(ctx, upb_MessageDef_FullName(m), name);
  o->field_count = 0;
  o->synthetic = false;

  if (upb_MessageDef_FindByNameWithSize(m, name.data, name.size, NULL, NULL)) {
    _upb_DefBuilder_Errf(ctx, "duplicate oneof name (%s)", o->full_name);
  }

  upb_value v = _upb_DefType_Pack(o, UPB_DEFTYPE_ONEOF);
  bool ok = _upb_MessageDef_Insert(m, name.data, name.size, v, ctx->arena);
  if (!ok) _upb_DefBuilder_OomErr(ctx);

  ok = upb_inttable_init(&o->itof, ctx->arena);
  if (!ok) _upb_DefBuilder_OomErr(ctx);

  ok = upb_strtable_init(&o->ntof, 4, ctx->arena);
  if (!ok) _upb_DefBuilder_OomErr(ctx);
}

// Allocate and initialize an array of |n| oneof defs.
upb_OneofDef* _upb_OneofDefs_New(
    upb_DefBuilder* ctx, int n,
    const google_protobuf_OneofDescriptorProto* const* protos,
    const google_protobuf_FeatureSet* parent_features, upb_MessageDef* m) {
  _upb_DefType_CheckPadding(sizeof(upb_OneofDef));

  upb_OneofDef* o = UPB_DEFBUILDER_ALLOCARRAY(ctx, upb_OneofDef, n);
  for (int i = 0; i < n; i++) {
    create_oneofdef(ctx, m, protos[i], parent_features, &o[i]);
  }
  return o;
}


#include <stddef.h>
#include <string.h>


// Must be last.

struct upb_ServiceDef {
  UPB_ALIGN_AS(8) const google_protobuf_ServiceOptions* opts;
  const google_protobuf_FeatureSet* resolved_features;
  const upb_FileDef* file;
  const char* full_name;
  upb_MethodDef* methods;
  int method_count;
  int index;
  upb_strtable ntom;
};

upb_ServiceDef* _upb_ServiceDef_At(const upb_ServiceDef* s, int index) {
  return (upb_ServiceDef*)&s[index];
}

const google_protobuf_ServiceOptions* upb_ServiceDef_Options(const upb_ServiceDef* s) {
  return s->opts;
}

bool upb_ServiceDef_HasOptions(const upb_ServiceDef* s) {
  return s->opts != (void*)kUpbDefOptDefault;
}

const google_protobuf_FeatureSet* upb_ServiceDef_ResolvedFeatures(
    const upb_ServiceDef* s) {
  return s->resolved_features;
}

const char* upb_ServiceDef_FullName(const upb_ServiceDef* s) {
  return s->full_name;
}

const char* upb_ServiceDef_Name(const upb_ServiceDef* s) {
  return _upb_DefBuilder_FullToShort(s->full_name);
}

int upb_ServiceDef_Index(const upb_ServiceDef* s) { return s->index; }

const upb_FileDef* upb_ServiceDef_File(const upb_ServiceDef* s) {
  return s->file;
}

int upb_ServiceDef_MethodCount(const upb_ServiceDef* s) {
  return s->method_count;
}

const upb_MethodDef* upb_ServiceDef_Method(const upb_ServiceDef* s, int i) {
  return (i < 0 || i >= s->method_count) ? NULL
                                         : _upb_MethodDef_At(s->methods, i);
}

const upb_MethodDef* upb_ServiceDef_FindMethodByName(const upb_ServiceDef* s,
                                                     const char* name) {
  return upb_ServiceDef_FindMethodByNameWithSize(s, name, strlen(name));
}

const upb_MethodDef* upb_ServiceDef_FindMethodByNameWithSize(
    const upb_ServiceDef* s, const char* name, size_t len) {
  upb_value val;

  if (!upb_strtable_lookup2(&s->ntom, name, len, &val)) {
    return NULL;
  }

  return _upb_DefType_Unpack(val, UPB_DEFTYPE_METHOD);
}

static void create_service(upb_DefBuilder* ctx,
                           const google_protobuf_ServiceDescriptorProto* svc_proto,
                           const google_protobuf_FeatureSet* parent_features,
                           upb_ServiceDef* s) {
  UPB_DEF_SET_OPTIONS(s->opts, ServiceDescriptorProto, ServiceOptions,
                      svc_proto);
  s->resolved_features = _upb_DefBuilder_ResolveFeatures(
      ctx, parent_features, google_protobuf_ServiceOptions_features(s->opts));

  // Must happen before _upb_DefBuilder_Add()
  s->file = _upb_DefBuilder_File(ctx);

  upb_StringView name = google_protobuf_ServiceDescriptorProto_name(svc_proto);
  const char* package = _upb_FileDef_RawPackage(s->file);
  s->full_name = _upb_DefBuilder_MakeFullName(ctx, package, name);
  _upb_DefBuilder_Add(ctx, s->full_name,
                      _upb_DefType_Pack(s, UPB_DEFTYPE_SERVICE));

  size_t n;
  const google_protobuf_MethodDescriptorProto* const* methods =
      google_protobuf_ServiceDescriptorProto_method(svc_proto, &n);
  s->method_count = n;
  bool ok = upb_strtable_init(&s->ntom, n, ctx->arena);
  if (!ok) _upb_DefBuilder_OomErr(ctx);
  s->methods = _upb_MethodDefs_New(ctx, n, methods, s->resolved_features, s);
}

upb_ServiceDef* _upb_ServiceDefs_New(
    upb_DefBuilder* ctx, int n,
    const google_protobuf_ServiceDescriptorProto* const* protos,
    const google_protobuf_FeatureSet* parent_features) {
  _upb_DefType_CheckPadding(sizeof(upb_ServiceDef));

  upb_ServiceDef* s = UPB_DEFBUILDER_ALLOCARRAY(ctx, upb_ServiceDef, n);
  for (int i = 0; i < n; i++) {
    create_service(ctx, protos[i], parent_features, &s[i]);
    s[i].index = i;
  }
  return s;
}

void _upb_ServiceDef_InsertMethod(upb_DefBuilder* ctx, upb_ServiceDef* s,
                                  const upb_MethodDef* m) {
  const char* shortname = upb_MethodDef_Name(m);
  const size_t shortnamelen = strlen(shortname);
  upb_value existing_v;
  if (upb_strtable_lookup(&s->ntom, shortname, &existing_v)) {
    _upb_DefBuilder_Errf(ctx, "duplicate method name (%s)", shortname);
  }
  const upb_value method_v = _upb_DefType_Pack(m, UPB_DEFTYPE_METHOD);
  bool ok = upb_strtable_insert(&s->ntom, shortname, shortnamelen, method_v,
                                ctx->arena);
  if (!ok) _upb_DefBuilder_OomErr(ctx);
}


#include <inttypes.h>
#include <math.h>
#include <setjmp.h>
#include <stdarg.h>
#include <stddef.h>
#include <stdint.h>
#include <string.h>


// Must be last.

typedef struct {
  upb_Arena* arena;
  jmp_buf err;
} upb_ToProto_Context;

#define CHK_OOM(val) \
  if (!(val)) UPB_LONGJMP(ctx->err, 1);

// We want to copy the options verbatim into the destination options proto.
// We use serialize+parse as our deep copy.
#define SET_OPTIONS(proto, desc_type, options_type, src, extreg)           \
  {                                                                        \
    size_t size;                                                           \
    /* MEM: could use a temporary arena here instead. */                   \
    char* pb = google_protobuf_##options_type##_serialize(src, ctx->arena, &size);  \
    CHK_OOM(pb);                                                           \
    google_protobuf_##options_type* dst =                                           \
        google_protobuf_##options_type##_parse_ex(pb, size, extreg, 0, ctx->arena); \
    CHK_OOM(dst);                                                          \
    google_protobuf_##desc_type##_set_options(proto, dst);                          \
  }

static upb_StringView strviewdup2(upb_ToProto_Context* ctx,
                                  upb_StringView str) {
  char* p = upb_Arena_Malloc(ctx->arena, str.size);
  CHK_OOM(p);
  memcpy(p, str.data, str.size);
  return (upb_StringView){.data = p, .size = str.size};
}

static upb_StringView strviewdup(upb_ToProto_Context* ctx, const char* s) {
  return strviewdup2(ctx, (upb_StringView){.data = s, .size = strlen(s)});
}

static upb_StringView qual_dup(upb_ToProto_Context* ctx, const char* s) {
  size_t n = strlen(s);
  char* p = upb_Arena_Malloc(ctx->arena, n + 1);
  CHK_OOM(p);
  p[0] = '.';
  memcpy(p + 1, s, n);
  return (upb_StringView){.data = p, .size = n + 1};
}

UPB_PRINTF(2, 3)
static upb_StringView printf_dup(upb_ToProto_Context* ctx, const char* fmt,
                                 ...) {
  const size_t max = 32;
  char* p = upb_Arena_Malloc(ctx->arena, max);
  CHK_OOM(p);
  va_list args;
  va_start(args, fmt);
  size_t n = _upb_vsnprintf(p, max, fmt, args);
  va_end(args);
  UPB_ASSERT(n < max);
  return (upb_StringView){.data = p, .size = n};
}

static bool upb_isprint(char ch) { return ch >= 0x20 && ch <= 0x7f; }

static int special_escape(char ch) {
  switch (ch) {
    // This is the same set of special escapes recognized by
    // absl::CEscape().
    case '\n':
      return 'n';
    case '\r':
      return 'r';
    case '\t':
      return 't';
    case '\\':
      return '\\';
    case '\'':
      return '\'';
    case '"':
      return '"';
    default:
      return -1;
  }
}

static upb_StringView default_bytes(upb_ToProto_Context* ctx,
                                    upb_StringView val) {
  size_t n = 0;
  for (size_t i = 0; i < val.size; i++) {
    char ch = val.data[i];
    if (special_escape(ch) >= 0)
      n += 2;  // '\C'
    else if (upb_isprint(ch))
      n += 1;
    else
      n += 4;  // '\123'
  }
  char* p = upb_Arena_Malloc(ctx->arena, n);
  CHK_OOM(p);
  char* dst = p;
  const char* src = val.data;
  const char* end = src + val.size;
  while (src < end) {
    unsigned char ch = *src++;
    if (special_escape(ch) >= 0) {
      *dst++ = '\\';
      *dst++ = (char)special_escape(ch);
    } else if (upb_isprint(ch)) {
      *dst++ = ch;
    } else {
      *dst++ = '\\';
      *dst++ = '0' + (ch >> 6);
      *dst++ = '0' + ((ch >> 3) & 0x7);
      *dst++ = '0' + (ch & 0x7);
    }
  }
  return (upb_StringView){.data = p, .size = n};
}

static upb_StringView default_string(upb_ToProto_Context* ctx,
                                     const upb_FieldDef* f) {
  upb_MessageValue d = upb_FieldDef_Default(f);
  upb_CType type = upb_FieldDef_CType(f);

  if (type == kUpb_CType_Float || type == kUpb_CType_Double) {
    double val = type == kUpb_CType_Float ? d.float_val : d.double_val;
    if (val == INFINITY) {
      return strviewdup(ctx, "inf");
    } else if (val == -INFINITY) {
      return strviewdup(ctx, "-inf");
    } else if (val != val) {
      return strviewdup(ctx, "nan");
    }
  }

  switch (upb_FieldDef_CType(f)) {
    case kUpb_CType_Bool:
      return strviewdup(ctx, d.bool_val ? "true" : "false");
    case kUpb_CType_Enum: {
      const upb_EnumDef* e = upb_FieldDef_EnumSubDef(f);
      const upb_EnumValueDef* ev =
          upb_EnumDef_FindValueByNumber(e, d.int32_val);
      return strviewdup(ctx, upb_EnumValueDef_Name(ev));
    }
    case kUpb_CType_Int64:
      return printf_dup(ctx, "%" PRId64, d.int64_val);
    case kUpb_CType_UInt64:
      return printf_dup(ctx, "%" PRIu64, d.uint64_val);
    case kUpb_CType_Int32:
      return printf_dup(ctx, "%" PRId32, d.int32_val);
    case kUpb_CType_UInt32:
      return printf_dup(ctx, "%" PRIu32, d.uint32_val);
    case kUpb_CType_Float:
      return printf_dup(ctx, "%.9g", d.float_val);
    case kUpb_CType_Double:
      return printf_dup(ctx, "%.17g", d.double_val);
    case kUpb_CType_String:
      return strviewdup2(ctx, d.str_val);
    case kUpb_CType_Bytes:
      return default_bytes(ctx, d.str_val);
    default:
      UPB_UNREACHABLE();
  }
}

static google_protobuf_DescriptorProto_ReservedRange* resrange_toproto(
    upb_ToProto_Context* ctx, const upb_MessageReservedRange* r) {
  google_protobuf_DescriptorProto_ReservedRange* proto =
      google_protobuf_DescriptorProto_ReservedRange_new(ctx->arena);
  CHK_OOM(proto);

  google_protobuf_DescriptorProto_ReservedRange_set_start(
      proto, upb_MessageReservedRange_Start(r));
  google_protobuf_DescriptorProto_ReservedRange_set_end(proto,
                                               upb_MessageReservedRange_End(r));

  return proto;
}

static google_protobuf_EnumDescriptorProto_EnumReservedRange* enumresrange_toproto(
    upb_ToProto_Context* ctx, const upb_EnumReservedRange* r) {
  google_protobuf_EnumDescriptorProto_EnumReservedRange* proto =
      google_protobuf_EnumDescriptorProto_EnumReservedRange_new(ctx->arena);
  CHK_OOM(proto);

  google_protobuf_EnumDescriptorProto_EnumReservedRange_set_start(
      proto, upb_EnumReservedRange_Start(r));
  google_protobuf_EnumDescriptorProto_EnumReservedRange_set_end(
      proto, upb_EnumReservedRange_End(r));

  return proto;
}

static google_protobuf_FieldDescriptorProto* fielddef_toproto(upb_ToProto_Context* ctx,
                                                     const upb_FieldDef* f) {
  google_protobuf_FieldDescriptorProto* proto =
      google_protobuf_FieldDescriptorProto_new(ctx->arena);
  CHK_OOM(proto);

  google_protobuf_FieldDescriptorProto_set_name(proto,
                                       strviewdup(ctx, upb_FieldDef_Name(f)));
  google_protobuf_FieldDescriptorProto_set_number(proto, upb_FieldDef_Number(f));

  if (upb_FieldDef_IsRequired(f) &&
      upb_FileDef_Edition(upb_FieldDef_File(f)) >= google_protobuf_EDITION_2023) {
    google_protobuf_FieldDescriptorProto_set_label(
        proto, google_protobuf_FieldDescriptorProto_LABEL_OPTIONAL);
  } else {
    google_protobuf_FieldDescriptorProto_set_label(proto, upb_FieldDef_Label(f));
  }
  if (upb_FieldDef_Type(f) == kUpb_FieldType_Group &&
      upb_FileDef_Edition(upb_FieldDef_File(f)) >= google_protobuf_EDITION_2023) {
    google_protobuf_FieldDescriptorProto_set_type(proto, kUpb_FieldType_Message);
  } else {
    google_protobuf_FieldDescriptorProto_set_type(proto, upb_FieldDef_Type(f));
  }

  if (upb_FieldDef_HasJsonName(f)) {
    google_protobuf_FieldDescriptorProto_set_json_name(
        proto, strviewdup(ctx, upb_FieldDef_JsonName(f)));
  }

  if (upb_FieldDef_IsSubMessage(f)) {
    google_protobuf_FieldDescriptorProto_set_type_name(
        proto,
        qual_dup(ctx, upb_MessageDef_FullName(upb_FieldDef_MessageSubDef(f))));
  } else if (upb_FieldDef_CType(f) == kUpb_CType_Enum) {
    google_protobuf_FieldDescriptorProto_set_type_name(
        proto, qual_dup(ctx, upb_EnumDef_FullName(upb_FieldDef_EnumSubDef(f))));
  }

  if (upb_FieldDef_IsExtension(f)) {
    google_protobuf_FieldDescriptorProto_set_extendee(
        proto,
        qual_dup(ctx, upb_MessageDef_FullName(upb_FieldDef_ContainingType(f))));
  }

  if (upb_FieldDef_HasDefault(f)) {
    google_protobuf_FieldDescriptorProto_set_default_value(proto,
                                                  default_string(ctx, f));
  }

  const upb_OneofDef* o = upb_FieldDef_ContainingOneof(f);
  if (o) {
    google_protobuf_FieldDescriptorProto_set_oneof_index(proto, upb_OneofDef_Index(o));
  }

  if (_upb_FieldDef_IsProto3Optional(f)) {
    google_protobuf_FieldDescriptorProto_set_proto3_optional(proto, true);
  }

  if (upb_FieldDef_HasOptions(f)) {
    SET_OPTIONS(proto, FieldDescriptorProto, FieldOptions,
                upb_FieldDef_Options(f),
                _upb_DefPool_GeneratedExtensionRegistry(
                    upb_FileDef_Pool(upb_FieldDef_File(f))));
  }

  return proto;
}

static google_protobuf_OneofDescriptorProto* oneofdef_toproto(upb_ToProto_Context* ctx,
                                                     const upb_OneofDef* o) {
  google_protobuf_OneofDescriptorProto* proto =
      google_protobuf_OneofDescriptorProto_new(ctx->arena);
  CHK_OOM(proto);

  google_protobuf_OneofDescriptorProto_set_name(proto,
                                       strviewdup(ctx, upb_OneofDef_Name(o)));

  if (upb_OneofDef_HasOptions(o)) {
    SET_OPTIONS(proto, OneofDescriptorProto, OneofOptions,
                upb_OneofDef_Options(o),
                _upb_DefPool_GeneratedExtensionRegistry(upb_FileDef_Pool(
                    upb_MessageDef_File(upb_OneofDef_ContainingType(o)))));
  }

  return proto;
}

static google_protobuf_EnumValueDescriptorProto* enumvaldef_toproto(
    upb_ToProto_Context* ctx, const upb_EnumValueDef* e) {
  google_protobuf_EnumValueDescriptorProto* proto =
      google_protobuf_EnumValueDescriptorProto_new(ctx->arena);
  CHK_OOM(proto);

  google_protobuf_EnumValueDescriptorProto_set_name(
      proto, strviewdup(ctx, upb_EnumValueDef_Name(e)));
  google_protobuf_EnumValueDescriptorProto_set_number(proto, upb_EnumValueDef_Number(e));

  if (upb_EnumValueDef_HasOptions(e)) {
    SET_OPTIONS(proto, EnumValueDescriptorProto, EnumValueOptions,
                upb_EnumValueDef_Options(e),
                _upb_DefPool_GeneratedExtensionRegistry(upb_FileDef_Pool(
                    upb_EnumDef_File(upb_EnumValueDef_Enum(e)))));
  }

  return proto;
}

static google_protobuf_EnumDescriptorProto* enumdef_toproto(upb_ToProto_Context* ctx,
                                                   const upb_EnumDef* e) {
  google_protobuf_EnumDescriptorProto* proto =
      google_protobuf_EnumDescriptorProto_new(ctx->arena);
  CHK_OOM(proto);

  google_protobuf_EnumDescriptorProto_set_name(proto,
                                      strviewdup(ctx, upb_EnumDef_Name(e)));

  int n = upb_EnumDef_ValueCount(e);
  google_protobuf_EnumValueDescriptorProto** vals =
      google_protobuf_EnumDescriptorProto_resize_value(proto, n, ctx->arena);
  CHK_OOM(vals);
  for (int i = 0; i < n; i++) {
    vals[i] = enumvaldef_toproto(ctx, upb_EnumDef_Value(e, i));
  }

  n = upb_EnumDef_ReservedRangeCount(e);
  google_protobuf_EnumDescriptorProto_EnumReservedRange** res_ranges =
      google_protobuf_EnumDescriptorProto_resize_reserved_range(proto, n, ctx->arena);
  for (int i = 0; i < n; i++) {
    res_ranges[i] = enumresrange_toproto(ctx, upb_EnumDef_ReservedRange(e, i));
  }

  n = upb_EnumDef_ReservedNameCount(e);
  upb_StringView* res_names =
      google_protobuf_EnumDescriptorProto_resize_reserved_name(proto, n, ctx->arena);
  for (int i = 0; i < n; i++) {
    res_names[i] = upb_EnumDef_ReservedName(e, i);
  }

  if (upb_EnumDef_HasOptions(e)) {
    SET_OPTIONS(proto, EnumDescriptorProto, EnumOptions, upb_EnumDef_Options(e),
                _upb_DefPool_GeneratedExtensionRegistry(
                    upb_FileDef_Pool(upb_EnumDef_File(e))));
  }

  google_protobuf_SymbolVisibility visibility = upb_EnumDef_Visibility(e);
  if (visibility != google_protobuf_VISIBILITY_UNSET) {
    google_protobuf_EnumDescriptorProto_set_visibility(proto, visibility);
  }

  return proto;
}

static google_protobuf_DescriptorProto_ExtensionRange* extrange_toproto(
    upb_ToProto_Context* ctx, const upb_MessageDef* m,
    const upb_ExtensionRange* e) {
  google_protobuf_DescriptorProto_ExtensionRange* proto =
      google_protobuf_DescriptorProto_ExtensionRange_new(ctx->arena);
  CHK_OOM(proto);

  google_protobuf_DescriptorProto_ExtensionRange_set_start(proto,
                                                  upb_ExtensionRange_Start(e));
  google_protobuf_DescriptorProto_ExtensionRange_set_end(proto,
                                                upb_ExtensionRange_End(e));

  if (upb_ExtensionRange_HasOptions(e)) {
    SET_OPTIONS(proto, DescriptorProto_ExtensionRange, ExtensionRangeOptions,
                upb_ExtensionRange_Options(e),
                _upb_DefPool_GeneratedExtensionRegistry(
                    upb_FileDef_Pool(upb_MessageDef_File(m))));
  }

  return proto;
}

static google_protobuf_DescriptorProto* msgdef_toproto(upb_ToProto_Context* ctx,
                                              const upb_MessageDef* m) {
  google_protobuf_DescriptorProto* proto = google_protobuf_DescriptorProto_new(ctx->arena);
  CHK_OOM(proto);

  google_protobuf_DescriptorProto_set_name(proto,
                                  strviewdup(ctx, upb_MessageDef_Name(m)));

  int n;

  n = upb_MessageDef_FieldCount(m);
  google_protobuf_FieldDescriptorProto** fields =
      google_protobuf_DescriptorProto_resize_field(proto, n, ctx->arena);
  CHK_OOM(fields);
  for (int i = 0; i < n; i++) {
    fields[i] = fielddef_toproto(ctx, upb_MessageDef_Field(m, i));
  }

  n = upb_MessageDef_OneofCount(m);
  google_protobuf_OneofDescriptorProto** oneofs =
      google_protobuf_DescriptorProto_resize_oneof_decl(proto, n, ctx->arena);
  for (int i = 0; i < n; i++) {
    oneofs[i] = oneofdef_toproto(ctx, upb_MessageDef_Oneof(m, i));
  }

  n = upb_MessageDef_NestedMessageCount(m);
  google_protobuf_DescriptorProto** nested_msgs =
      google_protobuf_DescriptorProto_resize_nested_type(proto, n, ctx->arena);
  for (int i = 0; i < n; i++) {
    nested_msgs[i] = msgdef_toproto(ctx, upb_MessageDef_NestedMessage(m, i));
  }

  n = upb_MessageDef_NestedEnumCount(m);
  google_protobuf_EnumDescriptorProto** nested_enums =
      google_protobuf_DescriptorProto_resize_enum_type(proto, n, ctx->arena);
  for (int i = 0; i < n; i++) {
    nested_enums[i] = enumdef_toproto(ctx, upb_MessageDef_NestedEnum(m, i));
  }

  n = upb_MessageDef_NestedExtensionCount(m);
  google_protobuf_FieldDescriptorProto** nested_exts =
      google_protobuf_DescriptorProto_resize_extension(proto, n, ctx->arena);
  for (int i = 0; i < n; i++) {
    nested_exts[i] =
        fielddef_toproto(ctx, upb_MessageDef_NestedExtension(m, i));
  }

  n = upb_MessageDef_ExtensionRangeCount(m);
  google_protobuf_DescriptorProto_ExtensionRange** ext_ranges =
      google_protobuf_DescriptorProto_resize_extension_range(proto, n, ctx->arena);
  for (int i = 0; i < n; i++) {
    ext_ranges[i] =
        extrange_toproto(ctx, m, upb_MessageDef_ExtensionRange(m, i));
  }

  n = upb_MessageDef_ReservedRangeCount(m);
  google_protobuf_DescriptorProto_ReservedRange** res_ranges =
      google_protobuf_DescriptorProto_resize_reserved_range(proto, n, ctx->arena);
  for (int i = 0; i < n; i++) {
    res_ranges[i] = resrange_toproto(ctx, upb_MessageDef_ReservedRange(m, i));
  }

  n = upb_MessageDef_ReservedNameCount(m);
  upb_StringView* res_names =
      google_protobuf_DescriptorProto_resize_reserved_name(proto, n, ctx->arena);
  for (int i = 0; i < n; i++) {
    res_names[i] = upb_MessageDef_ReservedName(m, i);
  }

  if (upb_MessageDef_HasOptions(m)) {
    SET_OPTIONS(proto, DescriptorProto, MessageOptions,
                upb_MessageDef_Options(m),
                _upb_DefPool_GeneratedExtensionRegistry(
                    upb_FileDef_Pool(upb_MessageDef_File(m))));
  }

  google_protobuf_SymbolVisibility visibility = upb_MessageDef_Visibility(m);
  if (visibility != google_protobuf_VISIBILITY_UNSET) {
    google_protobuf_DescriptorProto_set_visibility(proto, visibility);
  }

  return proto;
}

static google_protobuf_MethodDescriptorProto* methoddef_toproto(upb_ToProto_Context* ctx,
                                                       const upb_MethodDef* m) {
  google_protobuf_MethodDescriptorProto* proto =
      google_protobuf_MethodDescriptorProto_new(ctx->arena);
  CHK_OOM(proto);

  google_protobuf_MethodDescriptorProto_set_name(proto,
                                        strviewdup(ctx, upb_MethodDef_Name(m)));

  google_protobuf_MethodDescriptorProto_set_input_type(
      proto,
      qual_dup(ctx, upb_MessageDef_FullName(upb_MethodDef_InputType(m))));
  google_protobuf_MethodDescriptorProto_set_output_type(
      proto,
      qual_dup(ctx, upb_MessageDef_FullName(upb_MethodDef_OutputType(m))));

  if (upb_MethodDef_ClientStreaming(m)) {
    google_protobuf_MethodDescriptorProto_set_client_streaming(proto, true);
  }

  if (upb_MethodDef_ServerStreaming(m)) {
    google_protobuf_MethodDescriptorProto_set_server_streaming(proto, true);
  }

  if (upb_MethodDef_HasOptions(m)) {
    SET_OPTIONS(
        proto, MethodDescriptorProto, MethodOptions, upb_MethodDef_Options(m),
        _upb_DefPool_GeneratedExtensionRegistry(
            upb_FileDef_Pool(upb_ServiceDef_File(upb_MethodDef_Service(m)))));
  }

  return proto;
}

static google_protobuf_ServiceDescriptorProto* servicedef_toproto(
    upb_ToProto_Context* ctx, const upb_ServiceDef* s) {
  google_protobuf_ServiceDescriptorProto* proto =
      google_protobuf_ServiceDescriptorProto_new(ctx->arena);
  CHK_OOM(proto);

  google_protobuf_ServiceDescriptorProto_set_name(
      proto, strviewdup(ctx, upb_ServiceDef_Name(s)));

  size_t n = upb_ServiceDef_MethodCount(s);
  google_protobuf_MethodDescriptorProto** methods =
      google_protobuf_ServiceDescriptorProto_resize_method(proto, n, ctx->arena);
  for (size_t i = 0; i < n; i++) {
    methods[i] = methoddef_toproto(ctx, upb_ServiceDef_Method(s, i));
  }

  if (upb_ServiceDef_HasOptions(s)) {
    SET_OPTIONS(proto, ServiceDescriptorProto, ServiceOptions,
                upb_ServiceDef_Options(s),
                _upb_DefPool_GeneratedExtensionRegistry(
                    upb_FileDef_Pool(upb_ServiceDef_File(s))));
  }

  return proto;
}

static google_protobuf_FileDescriptorProto* filedef_toproto(upb_ToProto_Context* ctx,
                                                   const upb_FileDef* f) {
  google_protobuf_FileDescriptorProto* proto =
      google_protobuf_FileDescriptorProto_new(ctx->arena);
  CHK_OOM(proto);

  google_protobuf_FileDescriptorProto_set_name(proto,
                                      strviewdup(ctx, upb_FileDef_Name(f)));

  const char* package = upb_FileDef_Package(f);
  if (package) {
    size_t n = strlen(package);
    if (n) {
      google_protobuf_FileDescriptorProto_set_package(proto, strviewdup(ctx, package));
    }
  }

  google_protobuf_Edition edition = upb_FileDef_Edition(f);

  switch (edition) {
    case google_protobuf_EDITION_PROTO2:
      // We could set syntax to "proto2", but C++ omits it completely, which is
      // equivalent.
      break;
    case google_protobuf_EDITION_PROTO3:
      google_protobuf_FileDescriptorProto_set_syntax(proto, strviewdup(ctx, "proto3"));
      break;
    default:
      google_protobuf_FileDescriptorProto_set_syntax(proto, strviewdup(ctx, "editions"));
      google_protobuf_FileDescriptorProto_set_edition(proto, edition);
      break;
  }

  size_t n;
  n = upb_FileDef_DependencyCount(f);
  upb_StringView* deps =
      google_protobuf_FileDescriptorProto_resize_dependency(proto, n, ctx->arena);
  for (size_t i = 0; i < n; i++) {
    deps[i] = strviewdup(ctx, upb_FileDef_Name(upb_FileDef_Dependency(f, i)));
  }

  n = upb_FileDef_PublicDependencyCount(f);
  int32_t* public_deps =
      google_protobuf_FileDescriptorProto_resize_public_dependency(proto, n, ctx->arena);
  const int32_t* public_dep_nums = _upb_FileDef_PublicDependencyIndexes(f);
  if (n) memcpy(public_deps, public_dep_nums, n * sizeof(int32_t));

  n = upb_FileDef_WeakDependencyCount(f);
  int32_t* weak_deps =
      google_protobuf_FileDescriptorProto_resize_weak_dependency(proto, n, ctx->arena);
  const int32_t* weak_dep_nums = _upb_FileDef_WeakDependencyIndexes(f);
  if (n) memcpy(weak_deps, weak_dep_nums, n * sizeof(int32_t));

  n = upb_FileDef_TopLevelMessageCount(f);
  google_protobuf_DescriptorProto** msgs =
      google_protobuf_FileDescriptorProto_resize_message_type(proto, n, ctx->arena);
  for (size_t i = 0; i < n; i++) {
    msgs[i] = msgdef_toproto(ctx, upb_FileDef_TopLevelMessage(f, i));
  }

  n = upb_FileDef_TopLevelEnumCount(f);
  google_protobuf_EnumDescriptorProto** enums =
      google_protobuf_FileDescriptorProto_resize_enum_type(proto, n, ctx->arena);
  for (size_t i = 0; i < n; i++) {
    enums[i] = enumdef_toproto(ctx, upb_FileDef_TopLevelEnum(f, i));
  }

  n = upb_FileDef_ServiceCount(f);
  google_protobuf_ServiceDescriptorProto** services =
      google_protobuf_FileDescriptorProto_resize_service(proto, n, ctx->arena);
  for (size_t i = 0; i < n; i++) {
    services[i] = servicedef_toproto(ctx, upb_FileDef_Service(f, i));
  }

  n = upb_FileDef_TopLevelExtensionCount(f);
  google_protobuf_FieldDescriptorProto** exts =
      google_protobuf_FileDescriptorProto_resize_extension(proto, n, ctx->arena);
  for (size_t i = 0; i < n; i++) {
    exts[i] = fielddef_toproto(ctx, upb_FileDef_TopLevelExtension(f, i));
  }

  if (upb_FileDef_HasOptions(f)) {
    SET_OPTIONS(proto, FileDescriptorProto, FileOptions, upb_FileDef_Options(f),
                _upb_DefPool_GeneratedExtensionRegistry(upb_FileDef_Pool(f)));
  }

  return proto;
}

static google_protobuf_DescriptorProto* upb_ToProto_ConvertMessageDef(
    upb_ToProto_Context* const ctx, const upb_MessageDef* const m) {
  if (UPB_SETJMP(ctx->err)) return NULL;
  return msgdef_toproto(ctx, m);
}

google_protobuf_DescriptorProto* upb_MessageDef_ToProto(const upb_MessageDef* m,
                                               upb_Arena* a) {
  upb_ToProto_Context ctx = {a};
  return upb_ToProto_ConvertMessageDef(&ctx, m);
}

google_protobuf_EnumDescriptorProto* upb_ToProto_ConvertEnumDef(
    upb_ToProto_Context* const ctx, const upb_EnumDef* const e) {
  if (UPB_SETJMP(ctx->err)) return NULL;
  return enumdef_toproto(ctx, e);
}

google_protobuf_EnumDescriptorProto* upb_EnumDef_ToProto(const upb_EnumDef* e,
                                                upb_Arena* a) {
  upb_ToProto_Context ctx = {a};
  return upb_ToProto_ConvertEnumDef(&ctx, e);
}

google_protobuf_EnumValueDescriptorProto* upb_ToProto_ConvertEnumValueDef(
    upb_ToProto_Context* const ctx, const upb_EnumValueDef* e) {
  if (UPB_SETJMP(ctx->err)) return NULL;
  return enumvaldef_toproto(ctx, e);
}

google_protobuf_EnumValueDescriptorProto* upb_EnumValueDef_ToProto(
    const upb_EnumValueDef* e, upb_Arena* a) {
  upb_ToProto_Context ctx = {a};
  return upb_ToProto_ConvertEnumValueDef(&ctx, e);
}

google_protobuf_FieldDescriptorProto* upb_ToProto_ConvertFieldDef(
    upb_ToProto_Context* const ctx, const upb_FieldDef* f) {
  if (UPB_SETJMP(ctx->err)) return NULL;
  return fielddef_toproto(ctx, f);
}

google_protobuf_FieldDescriptorProto* upb_FieldDef_ToProto(const upb_FieldDef* f,
                                                  upb_Arena* a) {
  upb_ToProto_Context ctx = {a};
  return upb_ToProto_ConvertFieldDef(&ctx, f);
}

google_protobuf_OneofDescriptorProto* upb_ToProto_ConvertOneofDef(
    upb_ToProto_Context* const ctx, const upb_OneofDef* o) {
  if (UPB_SETJMP(ctx->err)) return NULL;
  return oneofdef_toproto(ctx, o);
}

google_protobuf_OneofDescriptorProto* upb_OneofDef_ToProto(const upb_OneofDef* o,
                                                  upb_Arena* a) {
  upb_ToProto_Context ctx = {a};
  return upb_ToProto_ConvertOneofDef(&ctx, o);
}

google_protobuf_FileDescriptorProto* upb_ToProto_ConvertFileDef(
    upb_ToProto_Context* const ctx, const upb_FileDef* const f) {
  if (UPB_SETJMP(ctx->err)) return NULL;
  return filedef_toproto(ctx, f);
}

google_protobuf_FileDescriptorProto* upb_FileDef_ToProto(const upb_FileDef* f,
                                                upb_Arena* a) {
  upb_ToProto_Context ctx = {a};
  return upb_ToProto_ConvertFileDef(&ctx, f);
}

google_protobuf_MethodDescriptorProto* upb_ToProto_ConvertMethodDef(
    upb_ToProto_Context* const ctx, const upb_MethodDef* m) {
  if (UPB_SETJMP(ctx->err)) return NULL;
  return methoddef_toproto(ctx, m);
}

google_protobuf_MethodDescriptorProto* upb_MethodDef_ToProto(
    const upb_MethodDef* const m, upb_Arena* a) {
  upb_ToProto_Context ctx = {a};
  return upb_ToProto_ConvertMethodDef(&ctx, m);
}

google_protobuf_ServiceDescriptorProto* upb_ToProto_ConvertServiceDef(
    upb_ToProto_Context* const ctx, const upb_ServiceDef* const s) {
  if (UPB_SETJMP(ctx->err)) return NULL;
  return servicedef_toproto(ctx, s);
}

google_protobuf_ServiceDescriptorProto* upb_ServiceDef_ToProto(const upb_ServiceDef* s,
                                                      upb_Arena* a) {
  upb_ToProto_Context ctx = {a};
  return upb_ToProto_ConvertServiceDef(&ctx, s);
}


#include <assert.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include <string.h>


// Our awkward dance for including fasttable only when it is enabled.
#if UPB_FASTTABLE
#define UPB_INCLUDE_FAST_DECODE
#endif

#ifdef UPB_INCLUDE_FAST_DECODE
#endif

#undef UPB_INCLUDE_FAST_DECODE

// Must be last.

// A few fake field types for our tables.
enum {
  kUpb_FakeFieldType_FieldNotFound = 0,
  kUpb_FakeFieldType_MessageSetItem = 19,
};

// DecodeOp: an action to be performed for a wire-type/field-type combination.
enum {
  // Special ops: we don't write data to regular fields for these.
  kUpb_DecodeOp_UnknownField = -1,
  kUpb_DecodeOp_MessageSetItem = -2,

  // Scalar-only ops.
  kUpb_DecodeOp_Scalar1Byte = 0,
  kUpb_DecodeOp_Scalar4Byte = 2,
  kUpb_DecodeOp_Scalar8Byte = 3,

  // Scalar/repeated ops.
  kUpb_DecodeOp_String = 4,
  kUpb_DecodeOp_Bytes = 5,
  kUpb_DecodeOp_SubMessage = 6,

  // Repeated-only ops (also see macros below).
  kUpb_DecodeOp_PackedEnum = 13,
};

// For packed fields it is helpful to be able to recover the lg2 of the data
// size from the op.
#define OP_FIXPCK_LG2(n) (n + 5) /* n in [2, 3] => op in [7, 8] */
#define OP_VARPCK_LG2(n) (n + 9) /* n in [0, 2, 3] => op in [9, 11, 12] */

typedef union {
  bool bool_val;
  uint32_t uint32_val;
  uint64_t uint64_val;
  uint32_t size;
} wireval;

static void _upb_Decoder_AssumeEpsHasErrorHandler(upb_Decoder* d) {
  UPB_ASSUME(upb_EpsCopyInputStream_HasErrorHandler(&d->input));
}

#define EPS(d) (_upb_Decoder_AssumeEpsHasErrorHandler(d), &(d)->input)

static bool _upb_Decoder_Reserve(upb_Decoder* d, upb_Array* arr, size_t elem) {
  bool need_realloc =
      arr->UPB_PRIVATE(capacity) - arr->UPB_PRIVATE(size) < elem;
  if (need_realloc && !UPB_PRIVATE(_upb_Array_Realloc)(
                          arr, arr->UPB_PRIVATE(size) + elem, &d->arena)) {
    upb_ErrorHandler_ThrowError(&d->err, kUpb_DecodeStatus_OutOfMemory);
  }
  return need_realloc;
}

typedef struct {
  const char* ptr;
  uint64_t val;
} _upb_DecodeLongVarintReturn;

// This is identical to _upb_Decoder_DecodeTag() except that the maximum value
// is INT32_MAX instead of UINT32_MAX.
UPB_FORCEINLINE
const char* upb_Decoder_DecodeSize(upb_Decoder* d, const char* ptr,
                                   uint32_t* size) {
  int sz;
  ptr = upb_WireReader_ReadSize(ptr, &sz, EPS(d));
  *size = sz;
  return ptr;
}

static void _upb_Decoder_MungeInt32(wireval* val) {
  if (!upb_IsLittleEndian()) {
    /* The next stage will memcpy(dst, &val, 4) */
    val->uint32_val = val->uint64_val;
  }
}

static void _upb_Decoder_Munge(const upb_MiniTableField* field, wireval* val) {
  switch (field->UPB_PRIVATE(descriptortype)) {
    case kUpb_FieldType_Bool:
      val->bool_val = val->uint64_val != 0;
      break;
    case kUpb_FieldType_SInt32: {
      uint32_t n = val->uint64_val;
      val->uint32_val = (n >> 1) ^ -(int32_t)(n & 1);
      break;
    }
    case kUpb_FieldType_SInt64: {
      uint64_t n = val->uint64_val;
      val->uint64_val = (n >> 1) ^ -(int64_t)(n & 1);
      break;
    }
    case kUpb_FieldType_Int32:
    case kUpb_FieldType_UInt32:
      _upb_Decoder_MungeInt32(val);
      break;
    case kUpb_FieldType_Enum:
      UPB_UNREACHABLE();
  }
}

static upb_Message* _upb_Decoder_NewSubMessage2(upb_Decoder* d,
                                                const upb_MiniTable* subl,
                                                const upb_MiniTableField* field,
                                                upb_Message** target) {
  UPB_ASSERT(subl);
  upb_Message* msg = _upb_Message_New(subl, &d->arena);
  if (!msg) upb_ErrorHandler_ThrowError(&d->err, kUpb_DecodeStatus_OutOfMemory);

  *target = msg;
  return msg;
}

static upb_Message* _upb_Decoder_NewSubMessage(upb_Decoder* d,
                                               const upb_MiniTableField* field,
                                               upb_Message** target) {
  const upb_MiniTable* subl = upb_MiniTable_GetSubMessageTable(field);
  return _upb_Decoder_NewSubMessage2(d, subl, field, target);
}

static const char* _upb_Decoder_ReadString2(upb_Decoder* d, const char* ptr,
                                            int size, upb_StringView* str,
                                            bool validate_utf8) {
  if (!_upb_Decoder_ReadString(d, &ptr, size, str, validate_utf8)) {
    upb_ErrorHandler_ThrowError(&d->err, kUpb_DecodeStatus_OutOfMemory);
  }
  return ptr;
}

UPB_FORCEINLINE
const char* _upb_Decoder_RecurseSubMessage(upb_Decoder* d, const char* ptr,
                                           upb_Message* submsg,
                                           const upb_MiniTable* subl,
                                           uint32_t expected_end_group) {
  if (--d->depth < 0) {
    upb_ErrorHandler_ThrowError(&d->err, kUpb_DecodeStatus_MaxDepthExceeded);
  }
  ptr = _upb_Decoder_DecodeMessage(d, ptr, submsg, subl);
  d->depth++;
  if (d->end_group != expected_end_group) {
    upb_ErrorHandler_ThrowError(&d->err, kUpb_DecodeStatus_Malformed);
  }
  return ptr;
}

UPB_FORCEINLINE
const char* _upb_Decoder_DecodeSubMessage(upb_Decoder* d, const char* ptr,
                                          upb_Message* submsg,
                                          const upb_MiniTableField* field,
                                          size_t size) {
  ptrdiff_t delta = upb_EpsCopyInputStream_PushLimit(&d->input, ptr, size);
  const upb_MiniTable* subl = upb_MiniTable_GetSubMessageTable(field);
  UPB_ASSERT(subl);
  ptr = _upb_Decoder_RecurseSubMessage(d, ptr, submsg, subl, DECODE_NOGROUP);
  upb_EpsCopyInputStream_PopLimit(&d->input, ptr, delta);
  return ptr;
}

UPB_FORCEINLINE
const char* _upb_Decoder_DecodeGroup(upb_Decoder* d, const char* ptr,
                                     upb_Message* submsg,
                                     const upb_MiniTable* subl,
                                     uint32_t number) {
  if (upb_EpsCopyInputStream_IsDone(EPS(d), &ptr)) {
    upb_ErrorHandler_ThrowError(&d->err, kUpb_DecodeStatus_Malformed);
  }
  ptr = _upb_Decoder_RecurseSubMessage(d, ptr, submsg, subl, number);
  d->end_group = DECODE_NOGROUP;
  return ptr;
}

UPB_FORCEINLINE
const char* _upb_Decoder_DecodeKnownGroup(upb_Decoder* d, const char* ptr,
                                          upb_Message* submsg,
                                          const upb_MiniTableField* field) {
  const upb_MiniTable* subl = upb_MiniTable_GetSubMessageTable(field);
  UPB_ASSERT(subl);
  return _upb_Decoder_DecodeGroup(d, ptr, submsg, subl,
                                  field->UPB_PRIVATE(number));
}

#define kUpb_Decoder_EncodeVarint32MaxSize 5
static char* upb_Decoder_EncodeVarint32(uint32_t val, char* ptr) {
  do {
    uint8_t byte = val & 0x7fU;
    val >>= 7;
    if (val) byte |= 0x80U;
    *(ptr++) = byte;
  } while (val);
  return ptr;
}

UPB_FORCEINLINE
void _upb_Decoder_AddEnumValueToUnknown(upb_Decoder* d, upb_Message* msg,
                                        const upb_MiniTableField* field,
                                        wireval* val) {
  // Unrecognized enum goes into unknown fields.
  // For packed fields the tag could be arbitrarily far in the past,
  // so we just re-encode the tag and value here.
  const uint32_t tag =
      ((uint32_t)field->UPB_PRIVATE(number) << 3) | kUpb_WireType_Varint;
  upb_Message* unknown_msg =
      field->UPB_PRIVATE(mode) & kUpb_LabelFlags_IsExtension ? d->original_msg
                                                             : msg;
  char buf[2 * kUpb_Decoder_EncodeVarint32MaxSize];
  char* end = buf;
  end = upb_Decoder_EncodeVarint32(tag, end);
  end = upb_Decoder_EncodeVarint32(val->uint64_val, end);

  if (!UPB_PRIVATE(_upb_Message_AddUnknown)(unknown_msg, buf, end - buf,
                                            &d->arena, kUpb_AddUnknown_Copy)) {
    upb_ErrorHandler_ThrowError(&d->err, kUpb_DecodeStatus_OutOfMemory);
  }
}

UPB_FORCEINLINE
const char* _upb_Decoder_DecodeFixedPacked(upb_Decoder* d, const char* ptr,
                                           upb_Array* arr, wireval* val,
                                           const upb_MiniTableField* field,
                                           int lg2) {
  upb_StringView sv;
  ptr = upb_EpsCopyInputStream_ReadStringEphemeral(&d->input, ptr, val->size,
                                                   &sv);
  if (!ptr) upb_ErrorHandler_ThrowError(&d->err, kUpb_DecodeStatus_Malformed);
  int mask = (1 << lg2) - 1;
  if (UPB_UNLIKELY((val->size & mask) != 0 || ptr == NULL)) {
    upb_ErrorHandler_ThrowError(&d->err, kUpb_DecodeStatus_Malformed);
  }
  size_t count = val->size >> lg2;
  if (count == 0) return ptr;
  _upb_Decoder_Reserve(d, arr, count);
  void* mem = UPB_PTR_AT(upb_Array_MutableDataPtr(arr),
                         arr->UPB_PRIVATE(size) << lg2, void);
  arr->UPB_PRIVATE(size) += count;
  if (upb_IsLittleEndian()) {
    memcpy(mem, sv.data, sv.size);
  } else {
    const char* src = sv.data;
    const char* src_end = src + sv.size;
    char* dst = mem;
    if (lg2 == 2) {
      for (; src < src_end; src += 4, dst += 4) {
        uint32_t x;
        memcpy(&x, src, 4);
        x = upb_BigEndian32(x);
        memcpy(dst, &x, 4);
      }
    } else {
      UPB_ASSERT(lg2 == 3);
      for (; src < src_end; src += 8, dst += 8) {
        uint64_t x;
        memcpy(&x, src, 8);
        x = upb_BigEndian64(x);
        memcpy(dst, &x, 8);
      }
    }
  }

  return ptr;
}

UPB_FORCEINLINE
const char* _upb_Decoder_DecodeVarintPacked(upb_Decoder* d, const char* ptr,
                                            upb_Array* arr, wireval* val,
                                            const upb_MiniTableField* field,
                                            int lg2) {
  int scale = 1 << lg2;
  ptrdiff_t delta = upb_EpsCopyInputStream_PushLimit(&d->input, ptr, val->size);
  char* out = UPB_PTR_AT(upb_Array_MutableDataPtr(arr),
                         arr->UPB_PRIVATE(size) << lg2, void);
  while (!upb_EpsCopyInputStream_IsDone(EPS(d), &ptr)) {
    wireval elem;
    ptr = upb_WireReader_ReadVarint(ptr, &elem.uint64_val, EPS(d));
    _upb_Decoder_Munge(field, &elem);
    if (_upb_Decoder_Reserve(d, arr, 1)) {
      out = UPB_PTR_AT(upb_Array_MutableDataPtr(arr),
                       arr->UPB_PRIVATE(size) << lg2, void);
    }
    arr->UPB_PRIVATE(size)++;
    memcpy(out, &elem, scale);
    out += scale;
  }
  upb_EpsCopyInputStream_PopLimit(&d->input, ptr, delta);
  return ptr;
}

UPB_NOINLINE
static const char* _upb_Decoder_DecodeEnumPacked(
    upb_Decoder* d, const char* ptr, upb_Message* msg, upb_Array* arr,
    const upb_MiniTableField* field, wireval* val) {
  const upb_MiniTableEnum* e = upb_MiniTable_GetSubEnumTable(field);
  ptrdiff_t delta = upb_EpsCopyInputStream_PushLimit(&d->input, ptr, val->size);
  char* out = UPB_PTR_AT(upb_Array_MutableDataPtr(arr),
                         arr->UPB_PRIVATE(size) * 4, void);
  while (!upb_EpsCopyInputStream_IsDone(EPS(d), &ptr)) {
    wireval elem;
    ptr = upb_WireReader_ReadVarint(ptr, &elem.uint64_val, EPS(d));
    if (!upb_MiniTableEnum_CheckValue(e, elem.uint64_val)) {
      _upb_Decoder_AddEnumValueToUnknown(d, msg, field, &elem);
      continue;
    }
    if (_upb_Decoder_Reserve(d, arr, 1)) {
      out = UPB_PTR_AT(upb_Array_MutableDataPtr(arr),
                       arr->UPB_PRIVATE(size) * 4, void);
    }
    arr->UPB_PRIVATE(size)++;
    memcpy(out, &elem, 4);
    out += 4;
  }
  upb_EpsCopyInputStream_PopLimit(&d->input, ptr, delta);
  return ptr;
}

static upb_Array* _upb_Decoder_CreateArray(upb_Decoder* d,
                                           const upb_MiniTableField* field) {
  const upb_FieldType field_type = field->UPB_PRIVATE(descriptortype);
  const size_t lg2 = UPB_PRIVATE(_upb_FieldType_SizeLg2)(field_type);
  upb_Array* ret = UPB_PRIVATE(_upb_Array_New)(&d->arena, 4, lg2);
  if (!ret) upb_ErrorHandler_ThrowError(&d->err, kUpb_DecodeStatus_OutOfMemory);
  return ret;
}

static const char* _upb_Decoder_DecodeToArray(upb_Decoder* d, const char* ptr,
                                              upb_Message* msg,
                                              const upb_MiniTableField* field,
                                              wireval* val, int op) {
  upb_Array** arrp = UPB_PTR_AT(msg, field->UPB_PRIVATE(offset), void);
  upb_Array* arr = *arrp;
  void* mem;

  if (arr) {
    _upb_Decoder_Reserve(d, arr, 1);
  } else {
    arr = _upb_Decoder_CreateArray(d, field);
    *arrp = arr;
  }

  switch (op) {
    case kUpb_DecodeOp_Scalar1Byte:
    case kUpb_DecodeOp_Scalar4Byte:
    case kUpb_DecodeOp_Scalar8Byte:
      /* Append scalar value. */
      mem = UPB_PTR_AT(upb_Array_MutableDataPtr(arr),
                       arr->UPB_PRIVATE(size) << op, void);
      arr->UPB_PRIVATE(size)++;
      memcpy(mem, val, 1 << op);
      return ptr;
    case kUpb_DecodeOp_String: {
      /* Append string. */
      upb_StringView* str = (upb_StringView*)upb_Array_MutableDataPtr(arr) +
                            arr->UPB_PRIVATE(size);
      ptr = _upb_Decoder_ReadString2(d, ptr, val->size, str,
                                     /*validate_utf8=*/true);
      arr->UPB_PRIVATE(size)++;
      return ptr;
    }
    case kUpb_DecodeOp_Bytes: {
      /* Append bytes. */
      upb_StringView* str = (upb_StringView*)upb_Array_MutableDataPtr(arr) +
                            arr->UPB_PRIVATE(size);
      ptr = _upb_Decoder_ReadString2(d, ptr, val->size, str,
                                     /*validate_utf8=*/false);
      arr->UPB_PRIVATE(size)++;
      return ptr;
    }
    case kUpb_DecodeOp_SubMessage: {
      /* Append submessage / group. */
      upb_Message** target =
          UPB_PTR_AT(upb_Array_MutableDataPtr(arr),
                     arr->UPB_PRIVATE(size) * sizeof(void*), upb_Message*);
      upb_Message* submsg = _upb_Decoder_NewSubMessage(d, field, target);
      arr->UPB_PRIVATE(size)++;
      if (UPB_UNLIKELY(field->UPB_PRIVATE(descriptortype) ==
                       kUpb_FieldType_Group)) {
        return _upb_Decoder_DecodeKnownGroup(d, ptr, submsg, field);
      } else {
        return _upb_Decoder_DecodeSubMessage(d, ptr, submsg, field, val->size);
      }
    }
    case OP_FIXPCK_LG2(2):
    case OP_FIXPCK_LG2(3):
      return _upb_Decoder_DecodeFixedPacked(d, ptr, arr, val, field,
                                            op - OP_FIXPCK_LG2(0));
    case OP_VARPCK_LG2(0):
    case OP_VARPCK_LG2(2):
    case OP_VARPCK_LG2(3):
      return _upb_Decoder_DecodeVarintPacked(d, ptr, arr, val, field,
                                             op - OP_VARPCK_LG2(0));
    case kUpb_DecodeOp_PackedEnum:
      return _upb_Decoder_DecodeEnumPacked(d, ptr, msg, arr, field, val);
    default:
      UPB_UNREACHABLE();
  }
}

static upb_Map* _upb_Decoder_CreateMap(upb_Decoder* d,
                                       const upb_MiniTable* entry) {
  // Maps descriptor type -> upb map size
  static const uint8_t kSizeInMap[] = {
      [0] = -1,  // invalid descriptor type
      [kUpb_FieldType_Double] = 8,
      [kUpb_FieldType_Float] = 4,
      [kUpb_FieldType_Int64] = 8,
      [kUpb_FieldType_UInt64] = 8,
      [kUpb_FieldType_Int32] = 4,
      [kUpb_FieldType_Fixed64] = 8,
      [kUpb_FieldType_Fixed32] = 4,
      [kUpb_FieldType_Bool] = 1,
      [kUpb_FieldType_String] = UPB_MAPTYPE_STRING,
      [kUpb_FieldType_Group] = sizeof(void*),
      [kUpb_FieldType_Message] = sizeof(void*),
      [kUpb_FieldType_Bytes] = UPB_MAPTYPE_STRING,
      [kUpb_FieldType_UInt32] = 4,
      [kUpb_FieldType_Enum] = 4,
      [kUpb_FieldType_SFixed32] = 4,
      [kUpb_FieldType_SFixed64] = 8,
      [kUpb_FieldType_SInt32] = 4,
      [kUpb_FieldType_SInt64] = 8,
  };

  const upb_MiniTableField* key_field = &entry->UPB_PRIVATE(fields)[0];
  const upb_MiniTableField* val_field = &entry->UPB_PRIVATE(fields)[1];
  char key_size = kSizeInMap[key_field->UPB_PRIVATE(descriptortype)];
  char val_size = kSizeInMap[val_field->UPB_PRIVATE(descriptortype)];
  UPB_ASSERT(key_field->UPB_PRIVATE(offset) == offsetof(upb_MapEntry, k));
  UPB_ASSERT(val_field->UPB_PRIVATE(offset) == offsetof(upb_MapEntry, v));
  upb_Map* ret = _upb_Map_New(&d->arena, key_size, val_size);
  if (!ret) upb_ErrorHandler_ThrowError(&d->err, kUpb_DecodeStatus_OutOfMemory);
  return ret;
}

UPB_NOINLINE static void _upb_Decoder_AddMapEntryUnknown(
    upb_Decoder* d, upb_Message* msg, const upb_MiniTableField* field,
    upb_Message* ent_msg, const upb_MiniTable* entry) {
  char* buf;
  size_t size;
  upb_EncodeStatus status =
      upb_Encode(ent_msg, entry, 0, &d->arena, &buf, &size);
  if (status != kUpb_EncodeStatus_Ok) {
    upb_ErrorHandler_ThrowError(&d->err, kUpb_DecodeStatus_OutOfMemory);
  }
  char delim_buf[2 * kUpb_Decoder_EncodeVarint32MaxSize];
  char* delim_end = delim_buf;
  uint32_t tag =
      ((uint32_t)field->UPB_PRIVATE(number) << 3) | kUpb_WireType_Delimited;
  delim_end = upb_Decoder_EncodeVarint32(tag, delim_end);
  delim_end = upb_Decoder_EncodeVarint32(size, delim_end);
  upb_StringView unknown[] = {
      {delim_buf, delim_end - delim_buf},
      {buf, size},
  };

  if (!UPB_PRIVATE(_upb_Message_AddUnknownV)(msg, &d->arena, unknown, 2)) {
    upb_ErrorHandler_ThrowError(&d->err, kUpb_DecodeStatus_OutOfMemory);
  }
}

static const char* _upb_Decoder_DecodeToMap(upb_Decoder* d, const char* ptr,
                                            upb_Message* msg,
                                            const upb_MiniTableField* field,
                                            wireval* val) {
  upb_Map** map_p = UPB_PTR_AT(msg, field->UPB_PRIVATE(offset), upb_Map*);
  upb_Map* map = *map_p;
  upb_MapEntry ent;
  UPB_ASSERT(upb_MiniTableField_Type(field) == kUpb_FieldType_Message);
  const upb_MiniTable* entry = upb_MiniTable_GetSubMessageTable(field);

  UPB_ASSERT(entry);
  UPB_ASSERT(entry->UPB_PRIVATE(field_count) == 2);
  UPB_ASSERT(upb_MiniTableField_IsScalar(&entry->UPB_PRIVATE(fields)[0]));
  UPB_ASSERT(upb_MiniTableField_IsScalar(&entry->UPB_PRIVATE(fields)[1]));

  if (!map) {
    map = _upb_Decoder_CreateMap(d, entry);
    *map_p = map;
  }

  // Parse map entry.
  memset(&ent, 0, sizeof(ent));

  bool value_is_message =
      entry->UPB_PRIVATE(fields)[1].UPB_PRIVATE(descriptortype) ==
          kUpb_FieldType_Message ||
      entry->UPB_PRIVATE(fields)[1].UPB_PRIVATE(descriptortype) ==
          kUpb_FieldType_Group;
  const upb_MiniTable* sub_table =
      value_is_message
          ? upb_MiniTable_GetSubMessageTable(&entry->UPB_PRIVATE(fields)[1])
          : NULL;
  upb_Message* sub_msg = NULL;

  if (sub_table) {
    // Create proactively to handle the case where it doesn't appear.
    _upb_Decoder_NewSubMessage(d, &entry->UPB_PRIVATE(fields)[1], &sub_msg);
    ent.v.val = upb_value_ptr(sub_msg);
  }

  ptr = _upb_Decoder_DecodeSubMessage(d, ptr, &ent.message, field, val->size);

  if (sub_msg && sub_table->UPB_PRIVATE(required_count)) {
    // If the map entry did not contain a value on the wire, `sub_msg` is an
    // empty message; we must check if it is missing any required fields. If the
    // value was present, this check is redundant but harmless.
    _upb_Decoder_CheckRequired(d, ptr, sub_msg, sub_table);
  }

  if (upb_Message_HasUnknown(&ent.message)) {
    _upb_Decoder_AddMapEntryUnknown(d, msg, field, &ent.message, entry);
  } else {
    if (_upb_Map_Insert(map, &ent.k, map->key_size, &ent.v, map->val_size,
                        &d->arena) == kUpb_MapInsertStatus_OutOfMemory) {
      upb_ErrorHandler_ThrowError(&d->err, kUpb_DecodeStatus_OutOfMemory);
    }
  }
  return ptr;
}

static const char* _upb_Decoder_DecodeToSubMessage(
    upb_Decoder* d, const char* ptr, upb_Message* msg,
    const upb_MiniTableField* field, wireval* val, int op) {
  void* mem = UPB_PTR_AT(msg, field->UPB_PRIVATE(offset), void);
  int type = field->UPB_PRIVATE(descriptortype);

  // Set presence if necessary.
  if (UPB_PRIVATE(_upb_MiniTableField_HasHasbit)(field)) {
    UPB_PRIVATE(_upb_Message_SetHasbit)(msg, field);
  } else if (upb_MiniTableField_IsInOneof(field)) {
    // Oneof case
    uint32_t* oneof_case = UPB_PRIVATE(_upb_Message_OneofCasePtr)(msg, field);
    if (op == kUpb_DecodeOp_SubMessage &&
        *oneof_case != field->UPB_PRIVATE(number)) {
      memset(mem, 0, sizeof(void*));
    }
    *oneof_case = field->UPB_PRIVATE(number);
  }

  // Store into message.
  switch (op) {
    case kUpb_DecodeOp_SubMessage: {
      upb_Message** submsgp = mem;
      upb_Message* submsg = *submsgp;
      if (!submsg) submsg = _upb_Decoder_NewSubMessage(d, field, submsgp);
      if (UPB_UNLIKELY(type == kUpb_FieldType_Group)) {
        ptr = _upb_Decoder_DecodeKnownGroup(d, ptr, submsg, field);
      } else {
        ptr = _upb_Decoder_DecodeSubMessage(d, ptr, submsg, field, val->size);
      }
      break;
    }
    case kUpb_DecodeOp_String:
      return _upb_Decoder_ReadString2(d, ptr, val->size, mem,
                                      /*validate_utf8=*/true);
    case kUpb_DecodeOp_Bytes:
      return _upb_Decoder_ReadString2(d, ptr, val->size, mem,
                                      /*validate_utf8=*/false);
    case kUpb_DecodeOp_Scalar8Byte:
      memcpy(mem, val, 8);
      break;
    case kUpb_DecodeOp_Scalar4Byte:
      memcpy(mem, val, 4);
      break;
    case kUpb_DecodeOp_Scalar1Byte:
      memcpy(mem, val, 1);
      break;
    default:
      UPB_UNREACHABLE();
  }

  return ptr;
}

enum {
  kStartItemTag = ((kUpb_MsgSet_Item << 3) | kUpb_WireType_StartGroup),
  kEndItemTag = ((kUpb_MsgSet_Item << 3) | kUpb_WireType_EndGroup),
  kTypeIdTag = ((kUpb_MsgSet_TypeId << 3) | kUpb_WireType_Varint),
  kMessageTag = ((kUpb_MsgSet_Message << 3) | kUpb_WireType_Delimited),
};

static void upb_Decoder_AddKnownMessageSetItem(
    upb_Decoder* d, upb_Message* msg, const upb_MiniTableExtension* item_mt,
    const char* data, uint32_t size) {
  upb_Extension* ext =
      UPB_PRIVATE(_upb_Message_GetOrCreateExtension)(msg, item_mt, &d->arena);
  if (UPB_UNLIKELY(!ext)) {
    upb_ErrorHandler_ThrowError(&d->err, kUpb_DecodeStatus_OutOfMemory);
  }
  upb_Message** submsgp = (upb_Message**)&ext->data.msg_val;
  upb_Message* submsg = _upb_Decoder_NewSubMessage2(
      d, ext->ext->UPB_PRIVATE(sub).UPB_PRIVATE(submsg),
      &ext->ext->UPB_PRIVATE(field), submsgp);
  // upb_Decode_LimitDepth() takes uint32_t, d->depth - 1 can not be negative.
  if (d->depth <= 1) {
    upb_ErrorHandler_ThrowError(&d->err, kUpb_DecodeStatus_MaxDepthExceeded);
  }
  upb_DecodeStatus status = upb_Decode(
      data, size, submsg, upb_MiniTableExtension_GetSubMessage(item_mt),
      d->extreg, upb_Decode_LimitDepth(d->options, d->depth - 1), &d->arena);
  if (status != kUpb_DecodeStatus_Ok) {
    upb_ErrorHandler_ThrowError(&d->err, status);
  }
}

static void upb_Decoder_AddUnknownMessageSetItem(upb_Decoder* d,
                                                 upb_Message* msg,
                                                 uint32_t type_id,
                                                 const char* message_data,
                                                 uint32_t message_size) {
  char buf[6 * kUpb_Decoder_EncodeVarint32MaxSize];
  char* ptr = buf;
  ptr = upb_Decoder_EncodeVarint32(kStartItemTag, ptr);
  ptr = upb_Decoder_EncodeVarint32(kTypeIdTag, ptr);
  ptr = upb_Decoder_EncodeVarint32(type_id, ptr);
  ptr = upb_Decoder_EncodeVarint32(kMessageTag, ptr);
  ptr = upb_Decoder_EncodeVarint32(message_size, ptr);
  char* split = ptr;

  ptr = upb_Decoder_EncodeVarint32(kEndItemTag, ptr);
  char* end = ptr;
  upb_StringView unknown[] = {
      {buf, split - buf},
      {message_data, message_size},
      {split, end - split},
  };
  if (!UPB_PRIVATE(_upb_Message_AddUnknownV)(msg, &d->arena, unknown, 3)) {
    upb_ErrorHandler_ThrowError(&d->err, kUpb_DecodeStatus_OutOfMemory);
  }
}

static void upb_Decoder_AddMessageSetItem(upb_Decoder* d, upb_Message* msg,
                                          const upb_MiniTable* t,
                                          uint32_t type_id, const char* data,
                                          uint32_t size) {
  const upb_MiniTableExtension* item_mt =
      upb_ExtensionRegistry_Lookup(d->extreg, t, type_id);
  if (item_mt) {
    upb_Decoder_AddKnownMessageSetItem(d, msg, item_mt, data, size);
  } else {
    upb_Decoder_AddUnknownMessageSetItem(d, msg, type_id, data, size);
  }
}

static const char* upb_Decoder_DecodeMessageSetItem(
    upb_Decoder* d, const char* ptr, upb_Message* msg,
    const upb_MiniTable* layout) {
  uint32_t type_id = 0;
  upb_StringView preserved = {NULL, 0};
  typedef enum {
    kUpb_HaveId = 1 << 0,
    kUpb_HavePayload = 1 << 1,
  } StateMask;
  StateMask state_mask = 0;
  while (!upb_EpsCopyInputStream_IsDone(EPS(d), &ptr)) {
    uint32_t tag;
    ptr = upb_WireReader_ReadTag(ptr, &tag, EPS(d));
    switch (tag) {
      case kEndItemTag:
        return ptr;
      case kTypeIdTag: {
        uint64_t tmp;
        ptr = upb_WireReader_ReadVarint(ptr, &tmp, EPS(d));
        if (state_mask & kUpb_HaveId) break;  // Ignore dup.
        state_mask |= kUpb_HaveId;
        type_id = tmp;
        if (state_mask & kUpb_HavePayload) {
          upb_Decoder_AddMessageSetItem(d, msg, layout, type_id, preserved.data,
                                        preserved.size);
        }
        break;
      }
      case kMessageTag: {
        uint32_t size;
        upb_StringView sv;
        ptr = upb_Decoder_DecodeSize(d, ptr, &size);
        ptr = upb_EpsCopyInputStream_ReadStringAlwaysAlias(&d->input, ptr, size,
                                                           &sv);
        if (!ptr) {
          upb_ErrorHandler_ThrowError(&d->err, kUpb_DecodeStatus_Malformed);
        }
        if (state_mask & kUpb_HavePayload) break;  // Ignore dup.
        state_mask |= kUpb_HavePayload;
        if (state_mask & kUpb_HaveId) {
          upb_Decoder_AddMessageSetItem(d, msg, layout, type_id, sv.data,
                                        sv.size);
        } else {
          // Out of order, we must preserve the payload.
          preserved = sv;
        }
        break;
      }
      default:
        // We do not preserve unexpected fields inside a message set item.
        ptr = _upb_WireReader_SkipValue(ptr, tag, d->depth, &d->input);
        break;
    }
  }
  upb_ErrorHandler_ThrowError(&d->err, kUpb_DecodeStatus_Malformed);
}

static upb_MiniTableField upb_Decoder_FieldNotFoundField = {
    0, 0, 0, 0, kUpb_FakeFieldType_FieldNotFound, 0};

UPB_NOINLINE const upb_MiniTableField* _upb_Decoder_FindExtensionField(
    upb_Decoder* d, const upb_MiniTable* t, uint32_t field_number, int ext_mode,
    uint32_t wire_type) {
  // Treat a message set as an extendable message if it is a delimited field.
  // This provides compatibility with encoders that are unaware of message
  // sets and serialize them as normal extensions.
  if (ext_mode == kUpb_ExtMode_Extendable ||
      (ext_mode == kUpb_ExtMode_IsMessageSet &&
       wire_type == kUpb_WireType_Delimited)) {
    const upb_MiniTableExtension* ext =
        upb_ExtensionRegistry_Lookup(d->extreg, t, field_number);
    if (ext) return &ext->UPB_PRIVATE(field);
  } else if (ext_mode == kUpb_ExtMode_IsMessageSet) {
    if (field_number == kUpb_MsgSet_Item) {
      static upb_MiniTableField item = {
          0, 0, 0, 0, kUpb_FakeFieldType_MessageSetItem, 0};
      return &item;
    }
  }
  return &upb_Decoder_FieldNotFoundField;
}

static const upb_MiniTableField* _upb_Decoder_FindField(upb_Decoder* d,
                                                        const upb_MiniTable* t,
                                                        uint32_t field_number,
                                                        uint32_t wire_type) {
  UPB_ASSERT(t);
  const upb_MiniTableField* field =
      upb_MiniTable_FindFieldByNumber(t, field_number);
  if (field) return field;

  if (d->extreg && t->UPB_PRIVATE(ext)) {
    return _upb_Decoder_FindExtensionField(d, t, field_number,
                                           t->UPB_PRIVATE(ext), wire_type);
  }

  return &upb_Decoder_FieldNotFoundField;  // Unknown field.
}

static int _upb_Decoder_GetVarintOp(const upb_MiniTableField* field) {
  static const int8_t kVarintOps[] = {
      [kUpb_FakeFieldType_FieldNotFound] = kUpb_DecodeOp_UnknownField,
      [kUpb_FieldType_Double] = kUpb_DecodeOp_UnknownField,
      [kUpb_FieldType_Float] = kUpb_DecodeOp_UnknownField,
      [kUpb_FieldType_Int64] = kUpb_DecodeOp_Scalar8Byte,
      [kUpb_FieldType_UInt64] = kUpb_DecodeOp_Scalar8Byte,
      [kUpb_FieldType_Int32] = kUpb_DecodeOp_Scalar4Byte,
      [kUpb_FieldType_Fixed64] = kUpb_DecodeOp_UnknownField,
      [kUpb_FieldType_Fixed32] = kUpb_DecodeOp_UnknownField,
      [kUpb_FieldType_Bool] = kUpb_DecodeOp_Scalar1Byte,
      [kUpb_FieldType_String] = kUpb_DecodeOp_UnknownField,
      [kUpb_FieldType_Group] = kUpb_DecodeOp_UnknownField,
      [kUpb_FieldType_Message] = kUpb_DecodeOp_UnknownField,
      [kUpb_FieldType_Bytes] = kUpb_DecodeOp_UnknownField,
      [kUpb_FieldType_UInt32] = kUpb_DecodeOp_Scalar4Byte,
      [kUpb_FieldType_Enum] = kUpb_DecodeOp_Scalar4Byte,
      [kUpb_FieldType_SFixed32] = kUpb_DecodeOp_UnknownField,
      [kUpb_FieldType_SFixed64] = kUpb_DecodeOp_UnknownField,
      [kUpb_FieldType_SInt32] = kUpb_DecodeOp_Scalar4Byte,
      [kUpb_FieldType_SInt64] = kUpb_DecodeOp_Scalar8Byte,
      [kUpb_FakeFieldType_MessageSetItem] = kUpb_DecodeOp_UnknownField,
  };

  return kVarintOps[field->UPB_PRIVATE(descriptortype)];
}

UPB_FORCEINLINE
void _upb_Decoder_CheckUnlinked(upb_Decoder* d, const upb_MiniTable* mt,
                                const upb_MiniTableField* field, int* op) {
  // If sub-message is not linked, treat as unknown.
  if (field->UPB_PRIVATE(mode) & kUpb_LabelFlags_IsExtension) return;
  const upb_MiniTable* mt_sub = upb_MiniTable_GetSubMessageTable(field);
  if (mt_sub != NULL) return;  // Normal case, sub-message is linked.
#ifndef NDEBUG
  const upb_MiniTableField* oneof = upb_MiniTable_GetOneof(mt, field);
  if (oneof) {
    // All other members of the oneof must be message fields that are also
    // unlinked.
    do {
      UPB_ASSERT(upb_MiniTableField_CType(oneof) == kUpb_CType_Message);
      const upb_MiniTable* oneof_sub = upb_MiniTable_GetSubMessageTable(oneof);
      UPB_ASSERT(!oneof_sub);
    } while (upb_MiniTable_NextOneofField(mt, &oneof));
  }
#endif  // NDEBUG
  *op = kUpb_DecodeOp_UnknownField;
}

UPB_FORCEINLINE
void _upb_Decoder_MaybeVerifyUtf8(upb_Decoder* d,
                                  const upb_MiniTableField* field, int* op) {
  UPB_ASSUME(field->UPB_PRIVATE(descriptortype) == kUpb_FieldType_Bytes);
  if (_upb_Decoder_FieldRequiresUtf8Validation(d, field)) {
    *op = kUpb_DecodeOp_String;
  }
}

static int _upb_Decoder_GetDelimitedOp(upb_Decoder* d, const upb_MiniTable* mt,
                                       const upb_MiniTableField* field) {
  enum { kRepeatedBase = 19 };

  static const int8_t kDelimitedOps[] = {
      // For non-repeated field type.
      [kUpb_FakeFieldType_FieldNotFound] =
          kUpb_DecodeOp_UnknownField,  // Field not found.
      [kUpb_FieldType_Double] = kUpb_DecodeOp_UnknownField,
      [kUpb_FieldType_Float] = kUpb_DecodeOp_UnknownField,
      [kUpb_FieldType_Int64] = kUpb_DecodeOp_UnknownField,
      [kUpb_FieldType_UInt64] = kUpb_DecodeOp_UnknownField,
      [kUpb_FieldType_Int32] = kUpb_DecodeOp_UnknownField,
      [kUpb_FieldType_Fixed64] = kUpb_DecodeOp_UnknownField,
      [kUpb_FieldType_Fixed32] = kUpb_DecodeOp_UnknownField,
      [kUpb_FieldType_Bool] = kUpb_DecodeOp_UnknownField,
      [kUpb_FieldType_String] = kUpb_DecodeOp_String,
      [kUpb_FieldType_Group] = kUpb_DecodeOp_UnknownField,
      [kUpb_FieldType_Message] = kUpb_DecodeOp_SubMessage,
      [kUpb_FieldType_Bytes] = kUpb_DecodeOp_Bytes,
      [kUpb_FieldType_UInt32] = kUpb_DecodeOp_UnknownField,
      [kUpb_FieldType_Enum] = kUpb_DecodeOp_UnknownField,
      [kUpb_FieldType_SFixed32] = kUpb_DecodeOp_UnknownField,
      [kUpb_FieldType_SFixed64] = kUpb_DecodeOp_UnknownField,
      [kUpb_FieldType_SInt32] = kUpb_DecodeOp_UnknownField,
      [kUpb_FieldType_SInt64] = kUpb_DecodeOp_UnknownField,
      [kUpb_FakeFieldType_MessageSetItem] = kUpb_DecodeOp_SubMessage,
      // For repeated field type.
      [kRepeatedBase + kUpb_FieldType_Double] = OP_FIXPCK_LG2(3),
      [kRepeatedBase + kUpb_FieldType_Float] = OP_FIXPCK_LG2(2),
      [kRepeatedBase + kUpb_FieldType_Int64] = OP_VARPCK_LG2(3),
      [kRepeatedBase + kUpb_FieldType_UInt64] = OP_VARPCK_LG2(3),
      [kRepeatedBase + kUpb_FieldType_Int32] = OP_VARPCK_LG2(2),
      [kRepeatedBase + kUpb_FieldType_Fixed64] = OP_FIXPCK_LG2(3),
      [kRepeatedBase + kUpb_FieldType_Fixed32] = OP_FIXPCK_LG2(2),
      [kRepeatedBase + kUpb_FieldType_Bool] = OP_VARPCK_LG2(0),
      [kRepeatedBase + kUpb_FieldType_String] = kUpb_DecodeOp_String,
      [kRepeatedBase + kUpb_FieldType_Group] = kUpb_DecodeOp_SubMessage,
      [kRepeatedBase + kUpb_FieldType_Message] = kUpb_DecodeOp_SubMessage,
      [kRepeatedBase + kUpb_FieldType_Bytes] = kUpb_DecodeOp_Bytes,
      [kRepeatedBase + kUpb_FieldType_UInt32] = OP_VARPCK_LG2(2),
      [kRepeatedBase + kUpb_FieldType_Enum] = kUpb_DecodeOp_PackedEnum,
      [kRepeatedBase + kUpb_FieldType_SFixed32] = OP_FIXPCK_LG2(2),
      [kRepeatedBase + kUpb_FieldType_SFixed64] = OP_FIXPCK_LG2(3),
      [kRepeatedBase + kUpb_FieldType_SInt32] = OP_VARPCK_LG2(2),
      [kRepeatedBase + kUpb_FieldType_SInt64] = OP_VARPCK_LG2(3),
      // Omitting kUpb_FakeFieldType_MessageSetItem, because we never emit a
      // repeated msgset type
  };

  int ndx = field->UPB_PRIVATE(descriptortype);
  if (upb_MiniTableField_IsArray(field)) ndx += kRepeatedBase;
  int op = kDelimitedOps[ndx];

  if (op == kUpb_DecodeOp_SubMessage) {
    _upb_Decoder_CheckUnlinked(d, mt, field, &op);
  } else if (op == kUpb_DecodeOp_Bytes) {
    _upb_Decoder_MaybeVerifyUtf8(d, field, &op);
  }

  return op;
}

UPB_FORCEINLINE
const char* _upb_Decoder_DecodeWireValue(upb_Decoder* d, const char* ptr,
                                         const upb_MiniTable* mt,
                                         const upb_MiniTableField* field,
                                         uint32_t wire_type, wireval* val,
                                         int* op) {
  static const unsigned kFixed32OkMask = (1 << kUpb_FieldType_Float) |
                                         (1 << kUpb_FieldType_Fixed32) |
                                         (1 << kUpb_FieldType_SFixed32);

  static const unsigned kFixed64OkMask = (1 << kUpb_FieldType_Double) |
                                         (1 << kUpb_FieldType_Fixed64) |
                                         (1 << kUpb_FieldType_SFixed64);

  switch (wire_type) {
    case kUpb_WireType_Varint:
      ptr = upb_WireReader_ReadVarint(ptr, &val->uint64_val, EPS(d));
      if (upb_MiniTableField_IsClosedEnum(field)) {
        const upb_MiniTableEnum* e = upb_MiniTable_GetSubEnumTable(field);
        if (!upb_MiniTableEnum_CheckValue(e, val->uint64_val)) {
          *op = kUpb_DecodeOp_UnknownField;
          return ptr;
        }
        _upb_Decoder_MungeInt32(val);
      } else {
        _upb_Decoder_Munge(field, val);
      }
      *op = _upb_Decoder_GetVarintOp(field);
      return ptr;
    case kUpb_WireType_32Bit:
      *op = kUpb_DecodeOp_Scalar4Byte;
      if (((1 << field->UPB_PRIVATE(descriptortype)) & kFixed32OkMask) == 0) {
        *op = kUpb_DecodeOp_UnknownField;
      }
      return upb_WireReader_ReadFixed32(ptr, &val->uint32_val, &d->input);
    case kUpb_WireType_64Bit:
      *op = kUpb_DecodeOp_Scalar8Byte;
      if (((1 << field->UPB_PRIVATE(descriptortype)) & kFixed64OkMask) == 0) {
        *op = kUpb_DecodeOp_UnknownField;
      }
      return upb_WireReader_ReadFixed64(ptr, &val->uint64_val, &d->input);
    case kUpb_WireType_Delimited:
      ptr = upb_Decoder_DecodeSize(d, ptr, &val->size);
      *op = _upb_Decoder_GetDelimitedOp(d, mt, field);
      return ptr;
    case kUpb_WireType_StartGroup:
      val->uint32_val = field->UPB_PRIVATE(number);
      if (field->UPB_PRIVATE(descriptortype) == kUpb_FieldType_Group) {
        *op = kUpb_DecodeOp_SubMessage;
        _upb_Decoder_CheckUnlinked(d, mt, field, op);
      } else if (field->UPB_PRIVATE(descriptortype) ==
                 kUpb_FakeFieldType_MessageSetItem) {
        *op = kUpb_DecodeOp_MessageSetItem;
      } else {
        *op = kUpb_DecodeOp_UnknownField;
      }
      return ptr;
    default:
      break;
  }
  upb_ErrorHandler_ThrowError(&d->err, kUpb_DecodeStatus_Malformed);
}

UPB_FORCEINLINE
const char* _upb_Decoder_DecodeKnownField(upb_Decoder* d, const char* ptr,
                                          upb_Message* msg,
                                          const upb_MiniTableField* field,
                                          int op, wireval* val) {
  uint8_t mode = field->UPB_PRIVATE(mode);

  if (UPB_UNLIKELY(mode & kUpb_LabelFlags_IsExtension)) {
    const upb_MiniTableExtension* ext_layout =
        (const upb_MiniTableExtension*)field;
    upb_Extension* ext = UPB_PRIVATE(_upb_Message_GetOrCreateExtension)(
        msg, ext_layout, &d->arena);
    if (UPB_UNLIKELY(!ext)) {
      upb_ErrorHandler_ThrowError(&d->err, kUpb_DecodeStatus_OutOfMemory);
    }
    d->original_msg = msg;
    msg = &ext->data.UPB_PRIVATE(ext_msg_val);
  }

  switch (mode & kUpb_FieldMode_Mask) {
    case kUpb_FieldMode_Array:
      return _upb_Decoder_DecodeToArray(d, ptr, msg, field, val, op);
    case kUpb_FieldMode_Map:
      return _upb_Decoder_DecodeToMap(d, ptr, msg, field, val);
    case kUpb_FieldMode_Scalar:
      return _upb_Decoder_DecodeToSubMessage(d, ptr, msg, field, val, op);
    default:
      UPB_UNREACHABLE();
  }
}

static const char* _upb_Decoder_DecodeUnknownField(
    upb_Decoder* d, const char* ptr, upb_Message* msg, uint32_t field_number,
    uint32_t wire_type, wireval val, const char* start) {
  if (field_number == 0) {
    upb_ErrorHandler_ThrowError(&d->err, kUpb_DecodeStatus_Malformed);
  }

  upb_EpsCopyInputStream_StartCapture(&d->input, start);

  if (wire_type == kUpb_WireType_Delimited) {
    upb_StringView sv;
    ptr = upb_EpsCopyInputStream_ReadStringEphemeral(&d->input, ptr, val.size,
                                                     &sv);
    if (!ptr) upb_ErrorHandler_ThrowError(&d->err, kUpb_DecodeStatus_Malformed);
  } else if (wire_type == kUpb_WireType_StartGroup) {
    ptr = UPB_PRIVATE(_upb_WireReader_SkipGroup)(ptr, field_number << 3,
                                                 d->depth, &d->input);
  }

  upb_StringView sv;
  upb_EpsCopyInputStream_EndCapture(&d->input, ptr, &sv);

  upb_AddUnknownMode mode = kUpb_AddUnknown_Copy;
  if (d->options & kUpb_DecodeOption_AliasString) {
    if (sv.data != d->input.buffer_start) {
      // If the data is not from the beginning of the input buffer, then we can
      // safely attempt to coalesce this region with the previous one.
      mode = kUpb_AddUnknown_AliasAllowMerge;
    } else {
      mode = kUpb_AddUnknown_Alias;
    }
  }

  if (!UPB_PRIVATE(_upb_Message_AddUnknown)(msg, sv.data, sv.size, &d->arena,
                                            mode)) {
    upb_ErrorHandler_ThrowError(&d->err, kUpb_DecodeStatus_OutOfMemory);
  }

  return ptr;
}

UPB_FORCEINLINE
const char* _upb_Decoder_DecodeFieldTag(upb_Decoder* d, const char* ptr,
                                        uint32_t* field_number,
                                        uint32_t* wire_type) {
  uint32_t tag;
  UPB_ASSERT(ptr < d->input.limit_ptr);
  ptr = upb_WireReader_ReadTag(ptr, &tag, EPS(d));
  *field_number = tag >> 3;
  *wire_type = tag & 7;
  return ptr;
}

UPB_FORCEINLINE
const char* _upb_Decoder_DecodeFieldData(
    upb_Decoder* d, const char* ptr, upb_Message* msg, const upb_MiniTable* mt,
    uint32_t field_number, uint32_t wire_type, const char* start) {
  int op;
  wireval val;

  const upb_MiniTableField* field =
      _upb_Decoder_FindField(d, mt, field_number, wire_type);
  ptr = _upb_Decoder_DecodeWireValue(d, ptr, mt, field, wire_type, &val, &op);

  if (op >= 0) {
    return _upb_Decoder_DecodeKnownField(d, ptr, msg, field, op, &val);
  } else {
    switch (op) {
      case kUpb_DecodeOp_UnknownField:
        return _upb_Decoder_DecodeUnknownField(d, ptr, msg, field_number,
                                               wire_type, val, start);
      case kUpb_DecodeOp_MessageSetItem:
        return upb_Decoder_DecodeMessageSetItem(d, ptr, msg, mt);
      default:
        UPB_UNREACHABLE();
    }
  }
}

static const char* _upb_Decoder_EndMessage(upb_Decoder* d, const char* ptr) {
  d->message_is_done = true;
  return ptr;
}

UPB_FORCEINLINE
const char* _upb_Decoder_DecodeFieldNoFast(upb_Decoder* d, const char* ptr,
                                           upb_Message* msg,
                                           const upb_MiniTable* mt) {
  uint32_t field_number;
  uint32_t wire_type;

  const char* start = ptr;
  ptr = _upb_Decoder_DecodeFieldTag(d, ptr, &field_number, &wire_type);

  if (wire_type == kUpb_WireType_EndGroup) {
    d->end_group = field_number;
    return _upb_Decoder_EndMessage(d, ptr);
  }

  ptr = _upb_Decoder_DecodeFieldData(d, ptr, msg, mt, field_number, wire_type,
                                     start);
  _upb_Decoder_Trace(d, 'M');
  return ptr;
}

UPB_FORCEINLINE
bool _upb_Decoder_TryDecodeMessageFast(upb_Decoder* d, const char** ptr,
                                       upb_Message* msg,
                                       const upb_MiniTable* mt,
                                       uint64_t last_field_index,
                                       uint64_t data) {
#ifdef UPB_ENABLE_FASTTABLE
  if (mt->UPB_PRIVATE(table_mask) == (unsigned char)-1 ||
      (d->options & kUpb_DecodeOption_DisableFastTable)) {
    // Fast table is unavailable or disabled.
    return false;
  }

  intptr_t table = decode_totable(mt);
  const char* start = *ptr;
  char* trace_next = _upb_Decoder_TraceNext(d);

  *ptr = upb_DecodeFast_Dispatch(d, *ptr, msg, table, 0, 0);

  if (d->message_is_done) {
    // The entire message was successfully parsed fast.
    return true;
  }

  // *ptr now points to the beginning of a field that could not be parsed fast.
  // It's possible that some fields were parsed fast, in which case *ptr will
  // have been updated. However, it's also possible that the very first field
  // encountered could not be parsed fast, in which case *ptr will be unchanged.
  //
  // If the fast decoder consumed any data, it must have emitted at least
  // one 'F' event into the trace buffer (in addition to the 'D' event
  // that is always emitted).
  UPB_ASSERT(_upb_Decoder_TracePtr(d) != trace_next || *ptr == start);
  _upb_Decoder_Trace(d, '<');
#endif
  return false;
}

UPB_FORCEINLINE
const char* _upb_Decoder_DecodeField(upb_Decoder* d, const char* ptr,
                                     upb_Message* msg, const upb_MiniTable* mt,
                                     uint64_t last_field_index, uint64_t data) {
  if (_upb_Decoder_TryDecodeMessageFast(d, &ptr, msg, mt, last_field_index,
                                        data)) {
    return ptr;
  } else if (upb_EpsCopyInputStream_IsDone(EPS(d), &ptr)) {
    return _upb_Decoder_EndMessage(d, ptr);
  }

  return _upb_Decoder_DecodeFieldNoFast(d, ptr, msg, mt);
}

UPB_NOINLINE
const char* _upb_Decoder_DecodeMessage(upb_Decoder* d, const char* ptr,
                                       upb_Message* msg,
                                       const upb_MiniTable* mt) {
  UPB_ASSERT(mt);
  UPB_ASSERT(d->message_is_done == false);

  do {
    ptr = _upb_Decoder_DecodeField(d, ptr, msg, mt, 0, 0);
  } while (!d->message_is_done);
  d->message_is_done = false;

  return UPB_UNLIKELY(mt && mt->UPB_PRIVATE(required_count))
             ? _upb_Decoder_CheckRequired(d, ptr, msg, mt)
             : ptr;
}

static upb_DecodeStatus _upb_Decoder_DecodeTop(struct upb_Decoder* d,
                                               const char* buf,
                                               upb_Message* msg,
                                               const upb_MiniTable* m) {
  _upb_Decoder_DecodeMessage(d, buf, msg, m);
  if (d->end_group != DECODE_NOGROUP) return kUpb_DecodeStatus_Malformed;
  if (d->missing_required) return kUpb_DecodeStatus_MissingRequired;
  return kUpb_DecodeStatus_Ok;
}

static upb_DecodeStatus upb_Decoder_Decode(upb_Decoder* const decoder,
                                           const char* const buf,
                                           upb_Message* const msg,
                                           const upb_MiniTable* const m,
                                           upb_Arena* const arena) {
  if (UPB_SETJMP(decoder->err.buf) == 0) {
    decoder->err.code = _upb_Decoder_DecodeTop(decoder, buf, msg, m);
  } else {
    UPB_ASSERT(decoder->err.code != kUpb_DecodeStatus_Ok);
  }

  return upb_Decoder_Destroy(decoder, arena);
}

static uint16_t upb_DecodeOptions_GetMaxDepth(uint32_t options) {
  return options >> 16;
}

uint16_t upb_DecodeOptions_GetEffectiveMaxDepth(uint32_t options) {
  uint16_t max_depth = upb_DecodeOptions_GetMaxDepth(options);
  return max_depth ? max_depth : kUpb_WireFormat_DefaultDepthLimit;
}

upb_DecodeStatus upb_Decode(const char* buf, size_t size, upb_Message* msg,
                            const upb_MiniTable* mt,
                            const upb_ExtensionRegistry* extreg, int options,
                            upb_Arena* arena) {
  UPB_ASSERT(!upb_Message_IsFrozen(msg));
  upb_Decoder decoder;
  buf = upb_Decoder_Init(&decoder, buf, size, extreg, options, arena, NULL, 0);

  return upb_Decoder_Decode(&decoder, buf, msg, mt, arena);
}

upb_DecodeStatus upb_DecodeWithTrace(const char* buf, size_t size,
                                     upb_Message* msg, const upb_MiniTable* mt,
                                     const upb_ExtensionRegistry* extreg,
                                     int options, upb_Arena* arena,
                                     char* trace_buf, size_t trace_size) {
  UPB_ASSERT(!upb_Message_IsFrozen(msg));
  upb_Decoder decoder;
  buf = upb_Decoder_Init(&decoder, buf, size, extreg, options, arena, trace_buf,
                         trace_size);

  return upb_Decoder_Decode(&decoder, buf, msg, mt, arena);
}

upb_DecodeStatus upb_DecodeLengthPrefixed(const char* buf, size_t size,
                                          upb_Message* msg,
                                          size_t* num_bytes_read,
                                          const upb_MiniTable* mt,
                                          const upb_ExtensionRegistry* extreg,
                                          int options, upb_Arena* arena) {
  // To avoid needing to make a Decoder just to decode the initial length,
  // hand-decode the leading varint for the message length here.
  uint64_t msg_len = 0;
  for (size_t i = 0;; ++i) {
    if (i >= size || i > 9) {
      return kUpb_DecodeStatus_Malformed;
    }
    uint64_t b = *buf;
    buf++;
    msg_len += (b & 0x7f) << (i * 7);
    if ((b & 0x80) == 0) {
      *num_bytes_read = i + 1 + msg_len;
      break;
    }
  }

  // If the total number of bytes we would read (= the bytes from the varint
  // plus however many bytes that varint says we should read) is larger then the
  // input buffer then error as malformed.
  if (*num_bytes_read > size) {
    return kUpb_DecodeStatus_Malformed;
  }
  if (msg_len > INT32_MAX) {
    return kUpb_DecodeStatus_Malformed;
  }

  return upb_Decode(buf, msg_len, msg, mt, extreg, options, arena);
}

const char* upb_DecodeStatus_String(upb_DecodeStatus status) {
  switch (status) {
    case kUpb_DecodeStatus_Ok:
      return "Ok";
    case kUpb_DecodeStatus_Malformed:
      return "Wire format was corrupt";
    case kUpb_DecodeStatus_OutOfMemory:
      return "Arena alloc failed";
    case kUpb_DecodeStatus_BadUtf8:
      return "String field had bad UTF-8";
    case kUpb_DecodeStatus_MaxDepthExceeded:
      return "Exceeded upb_DecodeOptions_MaxDepth";
    case kUpb_DecodeStatus_MissingRequired:
      return "Missing required field";
    default:
      return "Unknown decode status";
  }
}

#undef OP_FIXPCK_LG2
#undef OP_VARPCK_LG2

// We encode backwards, to avoid pre-computing lengths (one-pass encode).


#include <setjmp.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>


// Must be last.

static uint32_t encode_zz32(int32_t n) {
  return ((uint32_t)n << 1) ^ (n >> 31);
}
static uint64_t encode_zz64(int64_t n) {
  return ((uint64_t)n << 1) ^ (n >> 63);
}

typedef struct {
  upb_EncodeStatus status;
  jmp_buf err;
  upb_Arena* arena;
  // These should only be used for arithmetic and reallocation to allow full
  // aliasing analysis on the ptr argument.
  const char UPB_NODEREF *buf, *limit;
  int options;
  int depth;
  _upb_mapsorter sorter;
} upb_encstate;

UPB_NORETURN static void encode_err(upb_encstate* e, upb_EncodeStatus s) {
  UPB_ASSERT(s != kUpb_EncodeStatus_Ok);
  e->status = s;
  UPB_LONGJMP(e->err, 1);
}

// Subtraction is used for bounds checks, and the C standard says that pointer
// subtraction is UB if the pointers aren't part of the same array or one past
// the end, so we must avoid NULL - NULL. C++ defines it though.
static char initial_buf_sentinel;

UPB_NOINLINE static char* encode_growbuffer(char* ptr, upb_encstate* e,
                                            size_t bytes) {
  size_t old_size = e->limit - e->buf;
  size_t needed_size = bytes + (e->limit - ptr);
  if (needed_size < bytes) encode_err(e, kUpb_EncodeStatus_OutOfMemory);
  size_t new_size = upb_RoundUpToPowerOfTwo(UPB_MAX(128, needed_size));
  if (new_size == old_size) encode_err(e, kUpb_EncodeStatus_OutOfMemory);
  void* old_buf = e->buf == &initial_buf_sentinel ? NULL : (void*)e->buf;
  char* new_buf = upb_Arena_Realloc(e->arena, old_buf, old_size, new_size);

  if (!new_buf) encode_err(e, kUpb_EncodeStatus_OutOfMemory);

  // We want previous data at the end, realloc() put it at the beginning.
  // TODO: This is somewhat inefficient since we are copying twice.
  // Maybe create a realloc() that copies to the end of the new buffer?
  if (old_size > 0) {
    memmove(new_buf + new_size - old_size, new_buf, old_size);
  }

  e->buf = new_buf;
  e->limit = new_buf + new_size;
  return new_buf + new_size - needed_size;
}

/* Call to ensure that at least `bytes` bytes are available for writing at
 * ptr. */
UPB_FORCEINLINE
char* encode_reserve(char* ptr, upb_encstate* e, size_t bytes) {
  if ((size_t)(ptr - e->buf) < bytes) {
    return encode_growbuffer(ptr, e, bytes);
  }

  return ptr - bytes;
}

static char* encode_bytes_unchecked(char* ptr, upb_encstate* e,
                                    const void* data, size_t len) {
  if (len == 0) return ptr; /* memcpy() with zero size is UB */
  ptr -= len;
  memcpy(ptr, data, len);
  return ptr;
}

/* Writes the given bytes to the buffer, handling reserve/advance. */
static char* encode_bytes(char* ptr, upb_encstate* e, const void* data,
                          size_t len) {
  if (len == 0) return ptr; /* memcpy() with zero size is UB */
  ptr = encode_reserve(ptr, e, len);
  memcpy(ptr, data, len);
  return ptr;
}

static char* encode_fixed64_unchecked(char* ptr, upb_encstate* e,
                                      uint64_t val) {
  val = upb_BigEndian64(val);
  return encode_bytes_unchecked(ptr, e, &val, sizeof(uint64_t));
}

static char* encode_fixed32_unchecked(char* ptr, upb_encstate* e,
                                      uint32_t val) {
  val = upb_BigEndian32(val);
  return encode_bytes_unchecked(ptr, e, &val, sizeof(uint32_t));
}

#define UPB_PB_VARINT_MAX_LEN 10
#define UPB_PB_VARINT32_MAX_LEN 5

#if UPB_ARM64_ASM
// Each arm64 instruction encodes to 4 bytes, and it takes two intructions
// to process each byte of output, so we branch ahead by (4 + 4) * skip to
// avoid the remaining bytes. When BTI is on, we need to use specific
// "landing pad" instructions, so we pad those with nop to make it a power
// of 2, skipping 16 bytes at each stage instead of 8. This carries some
// overhead especially on in-order cores so they're not included unless
// building with branch protection.
#if UPB_ARM64_BTI_DEFAULT
// BTI is used with jc targets here because we don't control which register will
// be used for addr; if it's x16 or x17 a `br` is treated like a call.
#define UPB_BTI_JC "bti jc\n"
#define UPB_BTI_NOP "nop\n"
#define UPB_BTI_SHIFT_IMM "4\n"
#else
#define UPB_BTI_JC
#define UPB_BTI_NOP
#define UPB_BTI_SHIFT_IMM "3\n"
#endif
UPB_NOINLINE static char* encode_longvarint(char* ptr, upb_encstate* e,
                                            uint64_t val) {
  ptr = encode_reserve(ptr, e, UPB_PB_VARINT_MAX_LEN);
  uint64_t clz;
  __asm__("clz %[cnt], %[val]\n" : [cnt] "=r"(clz) : [val] "r"(val));

  uint32_t skip =
      UPB_PRIVATE(upb_WireWriter_VarintUnusedSizeFromLeadingZeros64)(clz);

  ptr += skip;
  uint64_t addr, mask;
  __asm__ volatile(
      // Formatter keeps merging short lines
      // clang-format off
      "adr %[addr], 0f\n"
      "add %[addr], %[addr], %[cnt], lsl #" UPB_BTI_SHIFT_IMM
      "mov %w[mask], #0x80\n"
      "br %[addr]\n"
      // Work around llvm/llvm-project#47432, where alignment directives inside
      // functions crash the compiler when generating SEH info on windows.
      #ifndef __SEH__
      ".p2align " UPB_BTI_SHIFT_IMM
      #endif
      "0:\n"
      // We don't need addr any more, but we've got the register for our whole
      // assembly block so we'll use it as scratch to store the shift+masked
      // values before storing them.
      // The following stores are unsigned offset stores:
      // strb Wt, [Xn, #imm]
      UPB_BTI_JC
      "orr %[addr], %[mask], %[val], lsr #56\n"
      "strb %w[addr], [%[ptr], #8]\n"
      UPB_BTI_NOP

      UPB_BTI_JC
      "orr %[addr], %[mask], %[val], lsr #49\n"
      "strb %w[addr], [%[ptr], #7]\n"
      UPB_BTI_NOP

      UPB_BTI_JC
      "orr %[addr], %[mask], %[val], lsr #42\n"
      "strb %w[addr], [%[ptr], #6]\n"
      UPB_BTI_NOP

      UPB_BTI_JC
      "orr %[addr], %[mask], %[val], lsr #35\n"
      "strb %w[addr], [%[ptr], #5]\n"
      UPB_BTI_NOP

      UPB_BTI_JC
      "orr %[addr], %[mask], %[val], lsr #28\n"
      "strb %w[addr], [%[ptr], #4]\n"
      UPB_BTI_NOP

      UPB_BTI_JC
      "orr %w[addr], %w[mask], %w[val], lsr #21\n"
      "strb %w[addr], [%[ptr], #3]\n"
      UPB_BTI_NOP

      UPB_BTI_JC
      "orr %w[addr], %w[mask], %w[val], lsr #14\n"
      "strb %w[addr], [%[ptr], #2]\n"
      UPB_BTI_NOP

      UPB_BTI_JC
      "orr %w[addr], %w[mask], %w[val], lsr #7\n"
      "strb %w[addr], [%[ptr], #1]\n"
      UPB_BTI_NOP

      UPB_BTI_JC
      "orr %w[addr], %w[val], #0x80\n"
      "strb %w[addr], [%[ptr]]\n"
      UPB_BTI_NOP

      UPB_BTI_JC
      // clang-format on
      : [addr] "=&r"(addr), [mask] "=&r"(mask)
      : [val] "r"(val), [ptr] "r"(ptr), [cnt] "r"((uint64_t)skip)
      : "memory");
  uint32_t continuations = UPB_PB_VARINT_MAX_LEN - 1 - skip;
  // msan can't instrument stores in inline assembly
  UPB_PRIVATE(upb_Xsan_MarkInitialized)(ptr, continuations);
  // Encode the final byte after the continuation bytes.
  ptr[continuations] = val >> (7 * continuations);
  return ptr;
}
#undef UPB_BTI_JC
#undef UPB_BTI_NOP
#undef UPB_BTI_SHIFT_IMM
#else
UPB_NOINLINE
static char* encode_longvarint(char* ptr, upb_encstate* e, uint64_t val) {
  ptr = encode_reserve(ptr, e, UPB_PB_VARINT_MAX_LEN);
  size_t len = 0;
  do {
    uint8_t byte = val & 0x7fU;
    val >>= 7;
    if (val) byte |= 0x80U;
    ptr[len++] = byte;
  } while (val);
  char* start = ptr + UPB_PB_VARINT_MAX_LEN - len;
  memmove(start, ptr, len);
  return start;
}
#endif

UPB_FORCEINLINE
char* encode_varint_unchecked(char* ptr, upb_encstate* e, uint64_t val) {
  if (val < 128) {
    --ptr;
    *ptr = val;
    return ptr;
  } else {
    return encode_longvarint(ptr, e, val);
  }
}
UPB_FORCEINLINE
char* encode_varint(char* ptr, upb_encstate* e, uint64_t val) {
  if (val < 128 && ptr != e->buf) {
    --ptr;
    *ptr = val;
    return ptr;
  } else {
    return encode_longvarint(ptr, e, val);
  }
}

UPB_NOINLINE
char* encode_longlength(char* ptr, upb_encstate* e, uint64_t val) {
  if (val > INT32_MAX) {
    encode_err(e, kUpb_EncodeStatus_MaxSizeExceeded);
  }
  return encode_longvarint(ptr, e, val);
}

UPB_FORCEINLINE
char* encode_length(char* ptr, upb_encstate* e, uint64_t val) {
  if (val < 128 && ptr != e->buf) {
    --ptr;
    *ptr = val;
    return ptr;
  } else {
    return encode_longlength(ptr, e, val);
  }
}

UPB_FORCEINLINE
char* encode_length_unchecked(char* ptr, upb_encstate* e, uint64_t val) {
  if (val < 128) {
    --ptr;
    *ptr = val;
    return ptr;
  } else {
    return encode_longlength(ptr, e, val);
  }
}

static char* encode_double_unchecked(char* ptr, upb_encstate* e, double d) {
  uint64_t u64;
  UPB_STATIC_ASSERT(sizeof(double) == sizeof(uint64_t), "bad double size");
  memcpy(&u64, &d, sizeof(uint64_t));
  return encode_fixed64_unchecked(ptr, e, u64);
}

static char* encode_float_unchecked(char* ptr, upb_encstate* e, float d) {
  uint32_t u32;
  UPB_STATIC_ASSERT(sizeof(float) == sizeof(uint32_t), "bad float size");
  memcpy(&u32, &d, sizeof(uint32_t));
  return encode_fixed32_unchecked(ptr, e, u32);
}

static char* encode_tag_unchecked(char* ptr, upb_encstate* e,
                                  uint32_t field_number, uint8_t wire_type) {
  return encode_varint_unchecked(ptr, e, (field_number << 3) | wire_type);
}

static char* encode_tag(char* ptr, upb_encstate* e, uint32_t field_number,
                        uint8_t wire_type) {
  return encode_varint(ptr, e, (field_number << 3) | wire_type);
}

static char* encode_fixedarray(char* ptr, upb_encstate* e, const upb_Array* arr,
                               size_t elem_size, uint32_t tag) {
  size_t bytes = upb_Array_Size(arr) * elem_size;
  const char* data = upb_Array_DataPtr(arr);
  const char* arr_ptr = data + bytes - elem_size;

  if (tag || !upb_IsLittleEndian()) {
    while (true) {
      if (elem_size == 4) {
        uint32_t val;
        memcpy(&val, arr_ptr, sizeof(val));
        val = upb_BigEndian32(val);
        ptr = encode_bytes(ptr, e, &val, elem_size);
      } else {
        UPB_ASSERT(elem_size == 8);
        uint64_t val;
        memcpy(&val, arr_ptr, sizeof(val));
        val = upb_BigEndian64(val);
        ptr = encode_bytes(ptr, e, &val, elem_size);
      }

      if (tag) {
        ptr = encode_varint(ptr, e, tag);
      }
      if (arr_ptr == data) break;
      arr_ptr -= elem_size;
    }
    return ptr;
  } else {
    return encode_bytes(ptr, e, data, bytes);
  }
}

static char* encode_message(char* ptr, upb_encstate* e, const upb_Message* msg,
                            const upb_MiniTable* m, size_t* size);

static char* encode_scalar(char* ptr, upb_encstate* e, const void* field_mem,
                           const upb_MiniTableField* f) {
  // Max size is tag + 10 bytes for max varint or 8 for largest fixed size
#define CASE(ctype, type, wtype, encodeval)                                   \
  {                                                                           \
    const size_t bytes = UPB_PB_VARINT32_MAX_LEN + UPB_PB_VARINT_MAX_LEN;     \
    ptr = encode_reserve(ptr, e, bytes);                                      \
    ptr += bytes;                                                             \
    const ctype val = *(const ctype*)field_mem;                               \
    ptr = encode_##type##_unchecked(ptr, e, encodeval);                       \
    return encode_tag_unchecked(ptr, e, upb_MiniTableField_Number(f), wtype); \
  }

  switch (f->UPB_PRIVATE(descriptortype)) {
    case kUpb_FieldType_Double:
      CASE(double, double, kUpb_WireType_64Bit, val);
    case kUpb_FieldType_Float:
      CASE(float, float, kUpb_WireType_32Bit, val);
    case kUpb_FieldType_Int64:
    case kUpb_FieldType_UInt64:
      CASE(uint64_t, varint, kUpb_WireType_Varint, val);
    case kUpb_FieldType_UInt32:
      CASE(uint32_t, varint, kUpb_WireType_Varint, val);
    case kUpb_FieldType_Int32:
    case kUpb_FieldType_Enum:
      CASE(int32_t, varint, kUpb_WireType_Varint, (int64_t)val);
    case kUpb_FieldType_SFixed64:
    case kUpb_FieldType_Fixed64:
      CASE(uint64_t, fixed64, kUpb_WireType_64Bit, val);
    case kUpb_FieldType_Fixed32:
    case kUpb_FieldType_SFixed32:
      CASE(uint32_t, fixed32, kUpb_WireType_32Bit, val);
    case kUpb_FieldType_Bool:
      CASE(bool, varint, kUpb_WireType_Varint, val);
    case kUpb_FieldType_SInt32:
      CASE(int32_t, varint, kUpb_WireType_Varint, encode_zz32(val));
    case kUpb_FieldType_SInt64:
      CASE(int64_t, varint, kUpb_WireType_Varint, encode_zz64(val));
    case kUpb_FieldType_String:
    case kUpb_FieldType_Bytes: {
      upb_StringView view = *(upb_StringView*)field_mem;
      const size_t max_size =
          UPB_PB_VARINT32_MAX_LEN + UPB_PB_VARINT32_MAX_LEN + view.size;
      ptr = encode_reserve(ptr, e, max_size);
      ptr += max_size;
      ptr = encode_bytes_unchecked(ptr, e, view.data, view.size);
      ptr = encode_length_unchecked(ptr, e, view.size);
      return encode_tag_unchecked(ptr, e, upb_MiniTableField_Number(f),
                                  kUpb_WireType_Delimited);
    }
    case kUpb_FieldType_Group: {
      size_t size;
      upb_Message* submsg = *(upb_Message**)field_mem;
      const upb_MiniTable* subm = upb_MiniTable_GetSubMessageTable(f);
      if (submsg == 0) {
        return ptr;
      }
      if (--e->depth == 0) encode_err(e, kUpb_EncodeStatus_MaxDepthExceeded);
      ptr = encode_tag(ptr, e, upb_MiniTableField_Number(f),
                       kUpb_WireType_EndGroup);
      ptr = encode_message(ptr, e, submsg, subm, &size);
      e->depth++;
      return encode_tag(ptr, e, upb_MiniTableField_Number(f),
                        kUpb_WireType_StartGroup);
    }
    case kUpb_FieldType_Message: {
      size_t size;
      upb_Message* submsg = *(upb_Message**)field_mem;
      const upb_MiniTable* subm = upb_MiniTable_GetSubMessageTable(f);
      if (submsg == 0) {
        return ptr;
      }
      if (--e->depth == 0) encode_err(e, kUpb_EncodeStatus_MaxDepthExceeded);
      ptr = encode_message(ptr, e, submsg, subm, &size);
      e->depth++;
      size_t max_size = UPB_PB_VARINT32_MAX_LEN + UPB_PB_VARINT32_MAX_LEN;
      ptr = encode_reserve(ptr, e, max_size);
      ptr += max_size;
      ptr = encode_length_unchecked(ptr, e, size);
      return encode_tag_unchecked(ptr, e, upb_MiniTableField_Number(f),
                                  kUpb_WireType_Delimited);
    }
    default:
      UPB_UNREACHABLE();
  }
#undef CASE
}

static char* encode_array(char* ptr, upb_encstate* e, const upb_Message* msg,
                          const upb_MiniTableField* f) {
  const upb_Array* arr = *UPB_PTR_AT(msg, f->UPB_PRIVATE(offset), upb_Array*);
  bool packed = upb_MiniTableField_IsPacked(f);
  size_t pre_len = e->limit - ptr;

  if (arr == NULL || upb_Array_Size(arr) == 0) {
    return ptr;
  }

#define VARINT_CASE(ctype, encode)                                         \
  {                                                                        \
    const ctype* start = upb_Array_DataPtr(arr);                           \
    const ctype* arr_ptr = start + upb_Array_Size(arr);                    \
    uint32_t tag =                                                         \
        packed ? 0 : (f->UPB_PRIVATE(number) << 3) | kUpb_WireType_Varint; \
    do {                                                                   \
      arr_ptr--;                                                           \
      ptr = encode_varint(ptr, e, encode);                                 \
      if (tag) {                                                           \
        ptr = encode_varint(ptr, e, tag);                                  \
      }                                                                    \
    } while (arr_ptr != start);                                            \
  }                                                                        \
  break;

#define TAG(wire_type) (packed ? 0 : (f->UPB_PRIVATE(number) << 3 | wire_type))

  switch (f->UPB_PRIVATE(descriptortype)) {
    case kUpb_FieldType_Double:
      ptr = encode_fixedarray(ptr, e, arr, sizeof(double),
                              TAG(kUpb_WireType_64Bit));
      break;
    case kUpb_FieldType_Float:
      ptr = encode_fixedarray(ptr, e, arr, sizeof(float),
                              TAG(kUpb_WireType_32Bit));
      break;
    case kUpb_FieldType_SFixed64:
    case kUpb_FieldType_Fixed64:
      ptr = encode_fixedarray(ptr, e, arr, sizeof(uint64_t),
                              TAG(kUpb_WireType_64Bit));
      break;
    case kUpb_FieldType_Fixed32:
    case kUpb_FieldType_SFixed32:
      ptr = encode_fixedarray(ptr, e, arr, sizeof(uint32_t),
                              TAG(kUpb_WireType_32Bit));
      break;
    case kUpb_FieldType_Int64:
    case kUpb_FieldType_UInt64:
      VARINT_CASE(uint64_t, *arr_ptr);
    case kUpb_FieldType_UInt32:
      VARINT_CASE(uint32_t, *arr_ptr);
    case kUpb_FieldType_Int32:
    case kUpb_FieldType_Enum:
      VARINT_CASE(int32_t, (int64_t)*arr_ptr);
    case kUpb_FieldType_Bool:
      VARINT_CASE(bool, *arr_ptr);
    case kUpb_FieldType_SInt32:
      VARINT_CASE(int32_t, encode_zz32(*arr_ptr));
    case kUpb_FieldType_SInt64:
      VARINT_CASE(int64_t, encode_zz64(*arr_ptr));
    case kUpb_FieldType_String:
    case kUpb_FieldType_Bytes: {
      const upb_StringView* start = upb_Array_DataPtr(arr);
      const upb_StringView* str_ptr = start + upb_Array_Size(arr);
      do {
        str_ptr--;
        ptr = encode_bytes(ptr, e, str_ptr->data, str_ptr->size);
        ptr = encode_length(ptr, e, str_ptr->size);
        ptr = encode_tag(ptr, e, upb_MiniTableField_Number(f),
                         kUpb_WireType_Delimited);
      } while (str_ptr != start);
      return ptr;
    }
    case kUpb_FieldType_Group: {
      const upb_Message* const* start = upb_Array_DataPtr(arr);
      const upb_Message* const* arr_ptr = start + upb_Array_Size(arr);
      const upb_MiniTable* subm = upb_MiniTable_GetSubMessageTable(f);
      if (--e->depth == 0) encode_err(e, kUpb_EncodeStatus_MaxDepthExceeded);
      do {
        size_t size;
        arr_ptr--;
        ptr = encode_tag(ptr, e, upb_MiniTableField_Number(f),
                         kUpb_WireType_EndGroup);
        ptr = encode_message(ptr, e, *arr_ptr, subm, &size);
        ptr = encode_tag(ptr, e, upb_MiniTableField_Number(f),
                         kUpb_WireType_StartGroup);
      } while (arr_ptr != start);
      e->depth++;
      return ptr;
    }
    case kUpb_FieldType_Message: {
      const upb_Message* const* start = upb_Array_DataPtr(arr);
      const upb_Message* const* arr_ptr = start + upb_Array_Size(arr);
      const upb_MiniTable* subm = upb_MiniTable_GetSubMessageTable(f);
      if (--e->depth == 0) encode_err(e, kUpb_EncodeStatus_MaxDepthExceeded);
      do {
        size_t size;
        arr_ptr--;
        ptr = encode_message(ptr, e, *arr_ptr, subm, &size);
        ptr = encode_length(ptr, e, size);
        ptr = encode_tag(ptr, e, upb_MiniTableField_Number(f),
                         kUpb_WireType_Delimited);
      } while (arr_ptr != start);
      e->depth++;
      return ptr;
    }
  }
#undef VARINT_CASE

  if (packed) {
    ptr = encode_length(ptr, e, e->limit - ptr - pre_len);
    ptr = encode_tag(ptr, e, upb_MiniTableField_Number(f),
                     kUpb_WireType_Delimited);
  }
  return ptr;
}

static char* encode_mapentry(char* ptr, upb_encstate* e, uint32_t number,
                             const upb_MiniTable* layout,
                             const upb_MapEntry* ent) {
  const upb_MiniTableField* key_field = upb_MiniTable_MapKey(layout);
  const upb_MiniTableField* val_field = upb_MiniTable_MapValue(layout);
  size_t pre_len = e->limit - ptr;
  size_t size;
  ptr = encode_scalar(ptr, e, &ent->v, val_field);
  ptr = encode_scalar(ptr, e, &ent->k, key_field);
  size = (e->limit - ptr) - pre_len;
  ptr = encode_length(ptr, e, size);
  ptr = encode_tag(ptr, e, number, kUpb_WireType_Delimited);
  return ptr;
}

static char* encode_map(char* ptr, upb_encstate* e, const upb_Message* msg,
                        const upb_MiniTableField* f) {
  const upb_Map* map = *UPB_PTR_AT(msg, f->UPB_PRIVATE(offset), const upb_Map*);
  const upb_MiniTable* layout = upb_MiniTable_MapEntrySubMessage(f);
  UPB_ASSERT(upb_MiniTable_FieldCount(layout) == 2);

  if (!map || !upb_Map_Size(map)) return ptr;

  if (e->options & kUpb_EncodeOption_Deterministic) {
    if (!map->UPB_PRIVATE(is_strtable)) {
      // For inttable, first encode the array part, then sort the table entries.
      intptr_t iter = UPB_INTTABLE_BEGIN;
      while ((size_t)++iter < map->t.inttable.array_size) {
        upb_value value = map->t.inttable.array[iter];
        if (upb_inttable_arrhas(&map->t.inttable, iter)) {
          upb_MapEntry ent;
          memcpy(&ent.k, &iter, sizeof(iter));
          _upb_map_fromvalue(value, &ent.v, map->val_size);
          ptr = encode_mapentry(ptr, e, upb_MiniTableField_Number(f), layout,
                                &ent);
        }
      }
    }
    _upb_sortedmap sorted;
    _upb_mapsorter_pushmap(
        &e->sorter, layout->UPB_PRIVATE(fields)[0].UPB_PRIVATE(descriptortype),
        map, &sorted);
    upb_MapEntry ent;
    while (_upb_sortedmap_next(&e->sorter, map, &sorted, &ent)) {
      ptr = encode_mapentry(ptr, e, upb_MiniTableField_Number(f), layout, &ent);
    }
    _upb_mapsorter_popmap(&e->sorter, &sorted);
  } else {
    upb_value val;
    if (map->UPB_PRIVATE(is_strtable)) {
      intptr_t iter = UPB_STRTABLE_BEGIN;
      upb_StringView strkey;
      while (upb_strtable_next2(&map->t.strtable, &strkey, &val, &iter)) {
        upb_MapEntry ent;
        _upb_map_fromkey(strkey, &ent.k, map->key_size);
        _upb_map_fromvalue(val, &ent.v, map->val_size);
        ptr =
            encode_mapentry(ptr, e, upb_MiniTableField_Number(f), layout, &ent);
      }
    } else {
      intptr_t iter = UPB_INTTABLE_BEGIN;
      uintptr_t intkey = 0;
      while (upb_inttable_next(&map->t.inttable, &intkey, &val, &iter)) {
        upb_MapEntry ent;
        memcpy(&ent.k, &intkey, map->key_size);
        _upb_map_fromvalue(val, &ent.v, map->val_size);
        ptr =
            encode_mapentry(ptr, e, upb_MiniTableField_Number(f), layout, &ent);
      }
    }
  }
  return ptr;
}

static bool encode_shouldencode(const upb_Message* msg,
                                const upb_MiniTableField* f) {
  if (f->presence == 0) {
    // Proto3 presence or map/array.
    const void* mem = UPB_PTR_AT(msg, f->UPB_PRIVATE(offset), void);
    switch (UPB_PRIVATE(_upb_MiniTableField_GetRep)(f)) {
      case kUpb_FieldRep_1Byte: {
        char ch;
        memcpy(&ch, mem, 1);
        return ch != 0;
      }
      case kUpb_FieldRep_4Byte: {
        uint32_t u32;
        memcpy(&u32, mem, 4);
        return u32 != 0;
      }
      case kUpb_FieldRep_8Byte: {
        uint64_t u64;
        memcpy(&u64, mem, 8);
        return u64 != 0;
      }
      case kUpb_FieldRep_StringView: {
        const upb_StringView* str = (const upb_StringView*)mem;
        return str->size != 0;
      }
      default:
        UPB_UNREACHABLE();
    }
  } else if (UPB_PRIVATE(_upb_MiniTableField_HasHasbit)(f)) {
    // Proto2 presence: hasbit.
    return UPB_PRIVATE(_upb_Message_GetHasbit)(msg, f);
  } else {
    // Field is in a oneof.
    return UPB_PRIVATE(_upb_Message_GetOneofCase)(msg, f) ==
           upb_MiniTableField_Number(f);
  }
}

static char* encode_field(char* ptr, upb_encstate* e, const upb_Message* msg,
                          const upb_MiniTableField* field) {
  switch (UPB_PRIVATE(_upb_MiniTableField_Mode)(field)) {
    case kUpb_FieldMode_Array:
      return encode_array(ptr, e, msg, field);
    case kUpb_FieldMode_Map:
      return encode_map(ptr, e, msg, field);
    case kUpb_FieldMode_Scalar:
      return encode_scalar(
          ptr, e, UPB_PTR_AT(msg, field->UPB_PRIVATE(offset), void), field);
    default:
      UPB_UNREACHABLE();
  }
}

static char* encode_msgset_item(char* ptr, upb_encstate* e,
                                const upb_MiniTableExtension* ext,
                                const upb_MessageValue ext_val) {
  size_t size;
  ptr = encode_tag(ptr, e, kUpb_MsgSet_Item, kUpb_WireType_EndGroup);
  ptr = encode_message(ptr, e, ext_val.msg_val,
                       upb_MiniTableExtension_GetSubMessage(ext), &size);
  ptr = encode_varint(ptr, e, size);
  ptr = encode_tag(ptr, e, kUpb_MsgSet_Message, kUpb_WireType_Delimited);
  ptr = encode_varint(ptr, e, upb_MiniTableExtension_Number(ext));
  ptr = encode_tag(ptr, e, kUpb_MsgSet_TypeId, kUpb_WireType_Varint);
  ptr = encode_tag(ptr, e, kUpb_MsgSet_Item, kUpb_WireType_StartGroup);
  return ptr;
}

static char* encode_ext(char* ptr, upb_encstate* e,
                        const upb_MiniTableExtension* ext,
                        upb_MessageValue ext_val, bool is_message_set) {
  if (UPB_UNLIKELY(is_message_set)) {
    ptr = encode_msgset_item(ptr, e, ext, ext_val);
  } else {
    ptr = encode_field(ptr, e, &ext_val.UPB_PRIVATE(ext_msg_val),
                       &ext->UPB_PRIVATE(field));
  }
  return ptr;
}

static char* encode_exts(char* ptr, upb_encstate* e, const upb_MiniTable* m,
                         const upb_Message* msg) {
  if (m->UPB_PRIVATE(ext) == kUpb_ExtMode_NonExtendable) return ptr;

  upb_Message_Internal* in = UPB_PRIVATE(_upb_Message_GetInternal)(msg);
  if (!in) return ptr;

  /* Encode all extensions together. Unlike C++, we do not attempt to keep
   * these in field number order relative to normal fields or even to each
   * other. */
  uintptr_t iter = kUpb_Message_ExtensionBegin;
  const upb_MiniTableExtension* ext;
  upb_MessageValue ext_val;
  if (!UPB_PRIVATE(_upb_Message_NextExtensionReverse)(msg, &ext, &ext_val,
                                                      &iter)) {
    // Message has no extensions.
    return ptr;
  }

  if (e->options & kUpb_EncodeOption_Deterministic) {
    _upb_sortedmap sorted;
    if (!_upb_mapsorter_pushexts(&e->sorter, in, &sorted)) {
      // TODO: b/378744096 - handle alloc failure
    }
    const upb_Extension* ext;
    while (_upb_sortedmap_nextext(&e->sorter, &sorted, &ext)) {
      ptr = encode_ext(ptr, e, ext->ext, ext->data,
                       m->UPB_PRIVATE(ext) == kUpb_ExtMode_IsMessageSet);
    }
    _upb_mapsorter_popmap(&e->sorter, &sorted);
  } else {
    do {
      ptr = encode_ext(ptr, e, ext, ext_val,
                       m->UPB_PRIVATE(ext) == kUpb_ExtMode_IsMessageSet);
    } while (UPB_PRIVATE(_upb_Message_NextExtensionReverse)(msg, &ext, &ext_val,
                                                            &iter));
  }
  return ptr;
}

static char* encode_message(char* ptr, upb_encstate* e, const upb_Message* msg,
                            const upb_MiniTable* m, size_t* size) {
  size_t pre_len = e->limit - ptr;

  if (e->options & kUpb_EncodeOption_CheckRequired) {
    if (m->UPB_PRIVATE(required_count)) {
      if (!UPB_PRIVATE(_upb_Message_IsInitializedShallow)(msg, m)) {
        encode_err(e, kUpb_EncodeStatus_MissingRequired);
      }
    }
  }

  if ((e->options & kUpb_EncodeOption_SkipUnknown) == 0) {
    size_t unknown_size = 0;
    uintptr_t iter = kUpb_Message_UnknownBegin;
    upb_StringView unknown;
    // Need to write in reverse order, but iteration is in-order; scan to
    // reserve capacity up front, then write in-order
    while (upb_Message_NextUnknown(msg, &unknown, &iter)) {
      unknown_size += unknown.size;
    }
    if (unknown_size != 0) {
      ptr = encode_reserve(ptr, e, unknown_size);
      char* tmp_ptr = ptr;
      iter = kUpb_Message_UnknownBegin;
      while (upb_Message_NextUnknown(msg, &unknown, &iter)) {
        memcpy(tmp_ptr, unknown.data, unknown.size);
        tmp_ptr += unknown.size;
      }
    }
  }

  ptr = encode_exts(ptr, e, m, msg);

  if (upb_MiniTable_FieldCount(m)) {
    const upb_MiniTableField* f =
        &m->UPB_PRIVATE(fields)[m->UPB_PRIVATE(field_count)];
    const upb_MiniTableField* first = &m->UPB_PRIVATE(fields)[0];
    while (f != first) {
      f--;
      if (encode_shouldencode(msg, f)) {
        ptr = encode_field(ptr, e, msg, f);
      }
    }
  }

  *size = (e->limit - ptr) - pre_len;
  return ptr;
}

static upb_EncodeStatus upb_Encoder_Encode(char* ptr,
                                           upb_encstate* const encoder,
                                           const upb_Message* const msg,
                                           const upb_MiniTable* const l,
                                           char** const buf, size_t* const size,
                                           bool prepend_len) {
  // Unfortunately we must continue to perform hackery here because there are
  // code paths which blindly copy the returned pointer without bothering to
  // check for errors until much later (b/235839510). So we still set *buf to
  // NULL on error and we still set it to non-NULL on a successful empty result.
  if (UPB_SETJMP(encoder->err) == 0) {
    size_t encoded_msg_size;
    ptr = encode_message(ptr, encoder, msg, l, &encoded_msg_size);
    if (prepend_len) {
      ptr = encode_length(ptr, encoder, encoded_msg_size);
    }
    *size = encoder->limit - ptr;
    if (*size == 0) {
      static char ch;
      *buf = &ch;
    } else {
      UPB_ASSERT(ptr);
      *buf = ptr;
    }
  } else {
    UPB_ASSERT(encoder->status != kUpb_EncodeStatus_Ok);
    *buf = NULL;
    *size = 0;
  }

  _upb_mapsorter_destroy(&encoder->sorter);
  return encoder->status;
}

static uint16_t upb_EncodeOptions_GetMaxDepth(uint32_t options) {
  return options >> 16;
}

uint16_t upb_EncodeOptions_GetEffectiveMaxDepth(uint32_t options) {
  uint16_t max_depth = upb_EncodeOptions_GetMaxDepth(options);
  return max_depth ? max_depth : kUpb_WireFormat_DefaultDepthLimit;
}

static upb_EncodeStatus _upb_Encode(const upb_Message* msg,
                                    const upb_MiniTable* l, int options,
                                    upb_Arena* arena, char** buf, size_t* size,
                                    bool prepend_len) {
  upb_encstate e;

  e.status = kUpb_EncodeStatus_Ok;
  e.arena = arena;
  e.buf = &initial_buf_sentinel;
  e.limit = &initial_buf_sentinel;
  e.depth = upb_EncodeOptions_GetEffectiveMaxDepth(options);
  e.options = options;
  _upb_mapsorter_init(&e.sorter);

  return upb_Encoder_Encode(&initial_buf_sentinel, &e, msg, l, buf, size,
                            prepend_len);
}

upb_EncodeStatus upb_Encode(const upb_Message* msg, const upb_MiniTable* l,
                            int options, upb_Arena* arena, char** buf,
                            size_t* size) {
  return _upb_Encode(msg, l, options, arena, buf, size, false);
}

upb_EncodeStatus upb_EncodeLengthPrefixed(const upb_Message* msg,
                                          const upb_MiniTable* l, int options,
                                          upb_Arena* arena, char** buf,
                                          size_t* size) {
  return _upb_Encode(msg, l, options, arena, buf, size, true);
}

const char* upb_EncodeStatus_String(upb_EncodeStatus status) {
  switch (status) {
    case kUpb_EncodeStatus_Ok:
      return "Ok";
    case kUpb_EncodeStatus_MissingRequired:
      return "Missing required field";
    case kUpb_EncodeStatus_MaxDepthExceeded:
      return "Max depth exceeded";
    case kUpb_EncodeStatus_OutOfMemory:
      return "Arena alloc failed";
    default:
      return "Unknown encode status";
  }
}



// Must be last.

UPB_NOINLINE
const char* _upb_Decoder_CheckRequired(upb_Decoder* d, const char* ptr,
                                       const upb_Message* msg,
                                       const upb_MiniTable* m) {
  UPB_ASSERT(m->UPB_PRIVATE(required_count));
  if (UPB_UNLIKELY(d->options & kUpb_DecodeOption_CheckRequired)) {
    d->missing_required =
        d->missing_required ||
        !UPB_PRIVATE(_upb_Message_IsInitializedShallow)(msg, m);
  }
  return ptr;
}


#include <stdint.h>
#include <string.h>


// Must be last.

const char* UPB_PRIVATE(upb_EpsCopyInputStream_ReturnError)(
    upb_EpsCopyInputStream* e) {
  e->error = true;
  if (e->err) upb_ErrorHandler_ThrowError(e->err, kUpb_ErrorCode_Malformed);
  return NULL;
}

const char* UPB_PRIVATE(upb_EpsCopyInputStream_IsDoneFallback)(
    struct upb_EpsCopyInputStream* e, const char* ptr, int overrun) {
  if (overrun < e->limit) {
    // Need to copy remaining data into patch buffer.
    UPB_ASSERT(overrun < kUpb_EpsCopyInputStream_SlopBytes);
    const char* old_end = ptr;
    const char* new_start = &e->patch[overrun];
    memset(&e->patch[kUpb_EpsCopyInputStream_SlopBytes], 0,
           kUpb_EpsCopyInputStream_SlopBytes);
    memcpy(e->patch, e->end, kUpb_EpsCopyInputStream_SlopBytes);
    ptr = new_start;
    e->end = &e->patch[kUpb_EpsCopyInputStream_SlopBytes];
    e->limit -= kUpb_EpsCopyInputStream_SlopBytes;
    e->limit_ptr = e->end + e->limit;
    UPB_ASSERT(ptr < e->limit_ptr);
    e->input_delta = (uintptr_t)old_end - (uintptr_t)new_start;
    UPB_PRIVATE(upb_EpsCopyInputStream_BoundsChecked)(e);
    return new_start;
  } else {
    UPB_ASSERT(overrun > e->limit);
    return UPB_PRIVATE(upb_EpsCopyInputStream_ReturnError)(e);
  }
}


#include <stddef.h>
#include <stdint.h>


// Must be last.

UPB_NOINLINE UPB_PRIVATE(_upb_WireReader_LongVarint)
    UPB_PRIVATE(_upb_WireReader_ReadLongVarint)(
        const char* ptr, uint64_t val, upb_EpsCopyInputStream* stream) {
  for (int i = 1; i < 10; i++) {
    uint64_t byte = (uint8_t)ptr[i];
    val += (byte - 1) << (i * 7);
    if (!(byte & 0x80)) {
      return (UPB_PRIVATE(_upb_WireReader_LongVarint)){ptr + i + 1, val};
    }
  }
  return (UPB_PRIVATE(_upb_WireReader_LongVarint)){
      UPB_PRIVATE(upb_EpsCopyInputStream_ReturnError)(stream), 0};
}

UPB_NOINLINE UPB_PRIVATE(_upb_WireReader_LongVarint)
    UPB_PRIVATE(_upb_WireReader_ReadLongTag)(const char* ptr, uint64_t val,
                                             upb_EpsCopyInputStream* stream) {
  for (int i = 1; i < 5; i++) {
    uint64_t byte = (uint8_t)ptr[i];
    val += (byte - 1) << (i * 7);
    if (!(byte & 0x80)) {
      if (val > UINT32_MAX) break;
      return (UPB_PRIVATE(_upb_WireReader_LongVarint)){ptr + i + 1, val};
    }
  }
  return (UPB_PRIVATE(_upb_WireReader_LongVarint)){
      UPB_PRIVATE(upb_EpsCopyInputStream_ReturnError)(stream), 0};
}

UPB_NOINLINE UPB_PRIVATE(_upb_WireReader_LongVarint)
    UPB_PRIVATE(_upb_WireReader_ReadLongSize)(const char* ptr, uint64_t val,
                                              upb_EpsCopyInputStream* stream) {
  for (int i = 1; i < 5; i++) {
    uint64_t byte = (uint8_t)ptr[i];
    val += (byte - 1) << (i * 7);
    if (!(byte & 0x80)) {
      if (val > INT32_MAX) break;
      return (UPB_PRIVATE(_upb_WireReader_LongVarint)){ptr + i + 1, val};
    }
  }
  return (UPB_PRIVATE(_upb_WireReader_LongVarint)){
      UPB_PRIVATE(upb_EpsCopyInputStream_ReturnError)(stream), 0};
}

const char* UPB_PRIVATE(_upb_WireReader_SkipGroup)(
    const char* ptr, uint32_t tag, int depth_limit,
    upb_EpsCopyInputStream* stream) {
  if (--depth_limit < 0) {
    return UPB_PRIVATE(upb_EpsCopyInputStream_ReturnError)(stream);
  }
  uint32_t end_group_tag = (tag & ~7ULL) | kUpb_WireType_EndGroup;
  while (!upb_EpsCopyInputStream_IsDone(stream, &ptr)) {
    uint32_t tag;
    ptr = upb_WireReader_ReadTag(ptr, &tag, stream);
    if (!ptr) break;
    if (tag == end_group_tag) return ptr;
    ptr = _upb_WireReader_SkipValue(ptr, tag, depth_limit, stream);
    if (!ptr) break;
  }
  // Encountered limit end before end group tag.
  return UPB_PRIVATE(upb_EpsCopyInputStream_ReturnError)(stream);
}

// This should #undef all macros #defined in def.inc

#undef UPB_SIZE
#undef UPB_PTR_AT
#undef UPB_SIZEOF_FLEX
#undef UPB_SIZEOF_FLEX_WOULD_OVERFLOW
#undef UPB_MAPTYPE_STRING
#undef UPB_EXPORT
#undef UPB_INLINE
#undef UPB_API
#undef UPBC_API
#undef UPB_API_INLINE
#undef UPB_API_INLINE_IF_NOT_GCC
#undef UPB_ALIGN_UP
#undef UPB_ALIGN_DOWN
#undef UPB_ALIGN_MALLOC
#undef UPB_ALIGN_OF
#undef UPB_ALIGN_AS
#undef UPB_STATIC_ASSERT
#undef UPB_STATIC_ASSERT_CONCAT
#undef UPB_STATIC_ASSERT_CONCAT_IMPL
#undef UPB_LIKELY
#undef UPB_UNLIKELY
#undef UPB_UNPREDICTABLE
#undef UPB_FORCEINLINE
#undef UPB_NOINLINE
#undef UPB_NORETURN
#undef UPB_PRINTF
#undef UPB_NODEREF
#undef UPB_MAX
#undef UPB_MIN
#undef UPB_UNUSED
#undef UPB_ASSUME
#undef UPB_ASSERT
#undef UPB_UNREACHABLE
#undef UPB_DEFAULT_MAX_BLOCK_SIZE
#undef UPB_SETJMP
#undef UPB_LONGJMP
#undef UPB_PTRADD
#undef UPB_MUSTTAIL
#undef UPB_PRESERVE_MOST
#undef UPB_PRESERVE_NONE
#undef UPB_FASTTABLE_SUPPORTED
#undef UPB_FASTTABLE_MASK
#undef UPB_FASTTABLE
#undef UPB_FASTTABLE_INIT
#undef UPB_POISON_MEMORY_REGION
#undef UPB_UNPOISON_MEMORY_REGION
#undef UPB_ASAN
#undef UPB_HWASAN
#undef UPB_HWASAN_POISON_TAG
#undef UPB_MSAN
#undef UPB_MALLOC_ALIGN
#undef UPB_TSAN
#undef UPB_DEPRECATED
#undef UPB_GNUC_MIN
#undef UPB_DESCRIPTOR_UPB_H_FILENAME
#undef UPB_DESC_MINITABLE
#undef UPB_IS_GOOGLE3
#undef UPB_ATOMIC
#undef UPB_USE_C11_ATOMICS
#undef UPB_USE_MSC_ATOMICS
#undef UPB_PRIVATE
#undef UPB_ONLYBITS
#undef UPB_LINKARR_DECLARE
#undef UPB_LINKARR_APPEND
#undef UPB_LINKARR_START
#undef UPB_LINKARR_STOP
#undef UPB_FUTURE_BREAKING_CHANGES
#undef UPB_HAS_ATTRIBUTE
#undef UPB_HAS_CPP_ATTRIBUTE
#undef UPB_HAS_BUILTIN
#undef UPB_HAS_EXTENSION
#undef UPB_HAS_FEATURE
#undef UPB_XSAN_MEMBER
#undef UPB_XSAN
#undef UPB_XSAN_STRUCT_SIZE
#undef UPB_ENABLE_REF_CYCLE_CHECKS
#undef UPB_ARM64_ASM
#undef UPB_ARM64_BTI_DEFAULT
#undef UPB_DEPRECATE_AND_INLINE
#undef UPB_MAYBE_ASSUME
#undef UPB_ATTR_CONST
