Package org.apache.groovy.contracts.generation

Class OldVariableGenerationUtility

java.lang.Object

org.apache.groovy.contracts.generation.OldVariableGenerationUtility

public class OldVariableGenerationUtility
extends Object

Central place where code generation for the old closure variable takes place.

Field Summary

Fields

Modifier and Type	Field	Description
static final String	OLD_VARIABLES_METHOD	Synthetic helper method name used to compute the old variable map for postconditions.

Constructor Summary

Constructors

Constructor	Description
OldVariableGenerationUtility()

Method Summary

Modifier and Type	Method	Description
static void	addOldVariableMethodNode(ClassNode classNode)	Creates a synthetic method handling generation of the old variable map.
static Expression	snapshotExpression(ClassNode type, Expression value)	Returns an expression that snapshots value (of declared type type) for storage in the old map.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

OLD_VARIABLES_METHOD

public static final String OLD_VARIABLES_METHOD

Synthetic helper method name used to compute the old variable map for postconditions.

See Also:

• Constant Field Values

Constructor Details

OldVariableGenerationUtility

public OldVariableGenerationUtility()

Method Details

addOldVariableMethodNode

public static void addOldVariableMethodNode(ClassNode classNode)

Creates a synthetic method handling generation of the old variable map. If a super class declares the same synthetic method it will be called and the results will be merged.

Parameters:

classNode - which contains postconditions, so an old variable generating method makes sense here.

snapshotExpression

public static Expression snapshotExpression(ClassNode type,
 Expression value)

Returns an expression that snapshots value (of declared type type) for storage in the old map. The snapshot is only a defensive copy when one is needed and possible:

• a value of a known-immutable type (per ImmutablePropertyUtils: primitives/wrappers, String, BigInteger/BigDecimal, the java.time.* types, enums, @Immutable/@KnownImmutable types, ...) is stored by reference, since it cannot change;
• a mutable Cloneable value is defensively copied with a null-safe clone(), so an in-place change in the method body is not also seen through old;
• any other value (e.g. a non-cloneable collection or a user type) cannot be generically copied, so its reference is stored as a best effort.

Reuses the same immutability/clone detection as @Immutable rather than an ad-hoc list.

Parameters:

type - the declared type of the value being snapshotted

value - the expression producing the value to snapshot

Returns:

the snapshot expression