Package proguard.evaluation

Class PartialEvaluator

java.lang.Object

proguard.evaluation.PartialEvaluator

All Implemented Interfaces:

AttributeVisitor, ExceptionInfoVisitor

public class PartialEvaluator
extends Object
implements AttributeVisitor, ExceptionInfoVisitor

This AttributeVisitor performs partial evaluation on the code attributes that it visits.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	PartialEvaluator.Builder
static class	PartialEvaluator.InstructionBlock	This class represents an instruction block that has to be executed, starting with a given state at a given instruction offset.

Field Summary

Fields

Modifier and Type	Field	Description
static final int	AT_CATCH_ENTRY
static final int	AT_METHOD_ENTRY
static boolean	ENABLE_NEW_EXCEPTIONS	Enables new exceptions to be thrown during evaluation.
static final int	NONE

Constructor Summary

Constructors

Constructor	Description
PartialEvaluator()	Creates a simple PartialEvaluator.
PartialEvaluator(ValueFactory valueFactory)	Creates a new PartialEvaluator.
PartialEvaluator(ValueFactory valueFactory, InvocationUnit invocationUnit, boolean evaluateAllCode)	Creates a new PartialEvaluator.
PartialEvaluator(ValueFactory valueFactory, InvocationUnit invocationUnit, boolean evaluateAllCode, InstructionVisitor extraInstructionVisitor)	Creates a new PartialEvaluator.

Method Summary

Modifier and Type	Method	Description
InstructionOffsetValue	branchOrigins(int instructionOffset)	Returns the instruction offsets that branch to the given instruction offset.
InstructionOffsetValue	branchTargets(int instructionOffset)	Returns the instruction offsets to which the given instruction offset branches.
TracedStack	getStackAfter(int instructionOffset)	Returns the stack after execution of the instruction at the given offset.
TracedStack	getStackBefore(int instructionOffset)	Returns the stack before execution of the instruction at the given offset.
TracedVariables	getVariablesAfter(int instructionOffset)	Returns the variables after execution of the instruction at the given offset.
TracedVariables	getVariablesBefore(int instructionOffset)	Returns the variables before execution of the instruction at the given offset.
boolean	isBranchOrExceptionTarget(int instructionOffset)	Returns whether the instruction at the given offset is the target of a branch instruction or an exception.
boolean	isBranchOrigin(int instructionOffset)	Returns whether the instruction at the given offset is the origin of a branch instruction.
boolean	isBranchTarget(int instructionOffset)	Returns whether the instruction at the given offset is the target of a branch instruction.
boolean	isCreation(int offset)	Returns whether the instruction at the given offset creates a new, uninitialized instance.
boolean	isExceptionHandler(int instructionOffset)	Returns whether the instruction at the given offset is the start of an exception handler.
boolean	isInitializer(int offset)	Returns whether the instruction at the given offset is the special invocation of an instance initializer.
boolean	isInstruction(int instructionOffset)	Returns whether there is an instruction at the given offset.
boolean	isSubroutine(int instructionOffset)	Returns whether the instruction at the given offset is part of a subroutine.
boolean	isSubroutineInvocation(int instructionOffset)	Returns whether the instruction at the given offset is a subroutine invocation.
boolean	isSubroutineReturning(int instructionOffset)	Returns whether the subroutine at the given offset is ever returning by means of a regular 'ret' instruction.
boolean	isSubroutineStart(int instructionOffset)	Returns whether the instruction at the given offset is the start of a subroutine.
boolean	isTarget(int instructionOffset)	Returns whether the instruction at the given offset is the target of any kind.
boolean	isTraced(int instructionOffset)	Returns whether the instruction at the given offset has ever been executed during the partial evaluation.
boolean	isTraced(int startOffset, int endOffset)	Returns whether a block of instructions is ever used.
PartialEvaluator	stopAnalysisAfterNEvaluations(int stopAnalysisAfterNEvaluations)	It the analysis visits an instruction this many times (this can happen e.g.
int	subroutineEnd(int instructionOffset)	Returns the offset after the subroutine that starts at the given offset.
InstructionVisitor	tracedInstructionFilter(boolean traced, InstructionVisitor instructionVisitor)	Returns a filtering version of the given instruction visitor that only visits traced or untraced instructions.
InstructionVisitor	tracedInstructionFilter(InstructionVisitor instructionVisitor)	Returns a filtering version of the given instruction visitor that only visits traced instructions.
void	visitAnyAttribute(Clazz clazz, Attribute attribute)	Visits any Attribute instance.
void	visitCodeAttribute(Clazz clazz, Method method, CodeAttribute codeAttribute)
void	visitCodeAttribute0(Clazz clazz, Method method, CodeAttribute codeAttribute)
void	visitExceptionInfo(Clazz clazz, Method method, CodeAttribute codeAttribute, ExceptionInfo exceptionInfo)

Methods inherited from class java.lang.Object

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

Methods inherited from interface proguard.classfile.attribute.visitor.AttributeVisitor

visitAnnotationDefaultAttribute, visitAnyAnnotationsAttribute, visitAnyParameterAnnotationsAttribute, visitAnyTypeAnnotationsAttribute, visitBootstrapMethodsAttribute, visitConstantValueAttribute, visitDeprecatedAttribute, visitDeprecatedAttribute, visitDeprecatedAttribute, visitDeprecatedAttribute, visitEnclosingMethodAttribute, visitExceptionsAttribute, visitInnerClassesAttribute, visitLineNumberTableAttribute, visitLocalVariableTableAttribute, visitLocalVariableTypeTableAttribute, visitMethodParametersAttribute, visitModuleAttribute, visitModuleMainClassAttribute, visitModulePackagesAttribute, visitNestHostAttribute, visitNestMembersAttribute, visitPermittedSubclassesAttribute, visitRecordAttribute, visitRuntimeInvisibleAnnotationsAttribute, visitRuntimeInvisibleAnnotationsAttribute, visitRuntimeInvisibleAnnotationsAttribute, visitRuntimeInvisibleAnnotationsAttribute, visitRuntimeInvisibleAnnotationsAttribute, visitRuntimeInvisibleParameterAnnotationsAttribute, visitRuntimeInvisibleTypeAnnotationsAttribute, visitRuntimeInvisibleTypeAnnotationsAttribute, visitRuntimeInvisibleTypeAnnotationsAttribute, visitRuntimeInvisibleTypeAnnotationsAttribute, visitRuntimeInvisibleTypeAnnotationsAttribute, visitRuntimeInvisibleTypeAnnotationsAttribute, visitRuntimeVisibleAnnotationsAttribute, visitRuntimeVisibleAnnotationsAttribute, visitRuntimeVisibleAnnotationsAttribute, visitRuntimeVisibleAnnotationsAttribute, visitRuntimeVisibleAnnotationsAttribute, visitRuntimeVisibleParameterAnnotationsAttribute, visitRuntimeVisibleTypeAnnotationsAttribute, visitRuntimeVisibleTypeAnnotationsAttribute, visitRuntimeVisibleTypeAnnotationsAttribute, visitRuntimeVisibleTypeAnnotationsAttribute, visitRuntimeVisibleTypeAnnotationsAttribute, visitRuntimeVisibleTypeAnnotationsAttribute, visitSignatureAttribute, visitSignatureAttribute, visitSignatureAttribute, visitSignatureAttribute, visitSignatureAttribute, visitSourceDebugExtensionAttribute, visitSourceDirAttribute, visitSourceFileAttribute, visitStackMapAttribute, visitStackMapTableAttribute, visitSyntheticAttribute, visitSyntheticAttribute, visitSyntheticAttribute, visitSyntheticAttribute, visitUnknownAttribute

Field Details

ENABLE_NEW_EXCEPTIONS

public static boolean ENABLE_NEW_EXCEPTIONS

Enables new exceptions to be thrown during evaluation. These are exceptions that are not thrown by the original ProGuard code. This is a temporary flag to allow the new exceptions to be tested. TODO: Remove this flag when the new exceptions are stable and will not break any dependent code.

NONE

public static final int NONE

See Also:

• Constant Field Values

AT_METHOD_ENTRY

public static final int AT_METHOD_ENTRY

See Also:

• Constant Field Values

AT_CATCH_ENTRY

public static final int AT_CATCH_ENTRY

See Also:

• Constant Field Values

Constructor Details

PartialEvaluator

public PartialEvaluator()

Creates a simple PartialEvaluator.

PartialEvaluator

public PartialEvaluator(ValueFactory valueFactory)

Creates a new PartialEvaluator.

Parameters:

valueFactory - the value factory that will create all values during evaluation.

PartialEvaluator

public PartialEvaluator(ValueFactory valueFactory,
 InvocationUnit invocationUnit,
 boolean evaluateAllCode)

Creates a new PartialEvaluator.

Parameters:

valueFactory - the value factory that will create all values during the evaluation.

invocationUnit - the invocation unit that will handle all communication with other fields and methods.

evaluateAllCode - a flag that specifies whether all casts, branch targets, and exception handlers should be evaluated, even if they are unnecessary or unreachable.

PartialEvaluator

public PartialEvaluator(ValueFactory valueFactory,
 InvocationUnit invocationUnit,
 boolean evaluateAllCode,
 InstructionVisitor extraInstructionVisitor)

Creates a new PartialEvaluator.

Parameters:

valueFactory - the value factory that will create all values during the evaluation.

invocationUnit - the invocation unit that will handle all communication with other fields and methods.

evaluateAllCode - a flag that specifies whether all branch targets and exception handlers should be evaluated, even if they are unreachable.

extraInstructionVisitor - an optional extra visitor for all instructions right before they are executed.

Method Details

visitAnyAttribute

public void visitAnyAttribute(Clazz clazz,
 Attribute attribute)

Description copied from interface: AttributeVisitor

Visits any Attribute instance. The more specific default implementations of this interface delegate to this method.

Specified by:

visitAnyAttribute in interface AttributeVisitor

visitCodeAttribute

public void visitCodeAttribute(Clazz clazz,
 Method method,
 CodeAttribute codeAttribute)

Specified by:

visitCodeAttribute in interface AttributeVisitor

visitCodeAttribute0

public void visitCodeAttribute0(Clazz clazz,
 Method method,
 CodeAttribute codeAttribute)

isTraced

public boolean isTraced(int startOffset,
 int endOffset)

Returns whether a block of instructions is ever used.

isTraced

public boolean isTraced(int instructionOffset)

Returns whether the instruction at the given offset has ever been executed during the partial evaluation.

isInstruction

public boolean isInstruction(int instructionOffset)

Returns whether there is an instruction at the given offset.

isTarget

public boolean isTarget(int instructionOffset)

Returns whether the instruction at the given offset is the target of any kind.

isBranchOrigin

public boolean isBranchOrigin(int instructionOffset)

Returns whether the instruction at the given offset is the origin of a branch instruction.

isBranchTarget

public boolean isBranchTarget(int instructionOffset)

Returns whether the instruction at the given offset is the target of a branch instruction.

isBranchOrExceptionTarget

public boolean isBranchOrExceptionTarget(int instructionOffset)

Returns whether the instruction at the given offset is the target of a branch instruction or an exception.

isExceptionHandler

public boolean isExceptionHandler(int instructionOffset)

Returns whether the instruction at the given offset is the start of an exception handler.

isSubroutineStart

public boolean isSubroutineStart(int instructionOffset)

Returns whether the instruction at the given offset is the start of a subroutine.

isSubroutineInvocation

public boolean isSubroutineInvocation(int instructionOffset)

Returns whether the instruction at the given offset is a subroutine invocation.

isSubroutine

public boolean isSubroutine(int instructionOffset)

Returns whether the instruction at the given offset is part of a subroutine.

isSubroutineReturning

public boolean isSubroutineReturning(int instructionOffset)

Returns whether the subroutine at the given offset is ever returning by means of a regular 'ret' instruction.

subroutineEnd

public int subroutineEnd(int instructionOffset)

Returns the offset after the subroutine that starts at the given offset.

isCreation

public boolean isCreation(int offset)

Returns whether the instruction at the given offset creates a new, uninitialized instance.

isInitializer

public boolean isInitializer(int offset)

Returns whether the instruction at the given offset is the special invocation of an instance initializer.

getVariablesBefore

public TracedVariables getVariablesBefore(int instructionOffset)

Returns the variables before execution of the instruction at the given offset.

getVariablesAfter

public TracedVariables getVariablesAfter(int instructionOffset)

Returns the variables after execution of the instruction at the given offset.

getStackBefore

public TracedStack getStackBefore(int instructionOffset)

Returns the stack before execution of the instruction at the given offset.

getStackAfter

public TracedStack getStackAfter(int instructionOffset)

Returns the stack after execution of the instruction at the given offset.

branchOrigins

public InstructionOffsetValue branchOrigins(int instructionOffset)

Returns the instruction offsets that branch to the given instruction offset.

branchTargets

public InstructionOffsetValue branchTargets(int instructionOffset)

Returns the instruction offsets to which the given instruction offset branches.

tracedInstructionFilter

public InstructionVisitor tracedInstructionFilter(InstructionVisitor instructionVisitor)

Returns a filtering version of the given instruction visitor that only visits traced instructions.

tracedInstructionFilter

public InstructionVisitor tracedInstructionFilter(boolean traced,
 InstructionVisitor instructionVisitor)

Returns a filtering version of the given instruction visitor that only visits traced or untraced instructions.

visitExceptionInfo

public void visitExceptionInfo(Clazz clazz,
 Method method,
 CodeAttribute codeAttribute,
 ExceptionInfo exceptionInfo)

Specified by:

visitExceptionInfo in interface ExceptionInfoVisitor

stopAnalysisAfterNEvaluations

public PartialEvaluator stopAnalysisAfterNEvaluations(int stopAnalysisAfterNEvaluations)

It the analysis visits an instruction this many times (this can happen e.g. for big switches), the analysis of this method is forcibly stopped and a ExcessiveComplexityException is thrown.