proguard.optimize.info.ParameterEscapedMarker Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of proguard-base Show documentation
Show all versions of proguard-base Show documentation
ProGuard is a free shrinker, optimizer, obfuscator, and preverifier for Java bytecode
/*
* ProGuard -- shrinking, optimization, obfuscation, and preverification
* of Java bytecode.
*
* Copyright (c) 2002-2021 Guardsquare NV
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the Free
* Software Foundation; either version 2 of the License, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package proguard.optimize.info;
import proguard.classfile.*;
import proguard.classfile.attribute.*;
import proguard.classfile.attribute.visitor.*;
import proguard.classfile.constant.*;
import proguard.classfile.constant.visitor.ConstantVisitor;
import proguard.classfile.instruction.*;
import proguard.classfile.instruction.visitor.InstructionVisitor;
import proguard.classfile.util.*;
import proguard.classfile.visitor.*;
import proguard.evaluation.*;
import proguard.evaluation.value.*;
import proguard.optimize.evaluation.*;
/**
* This ClassPoolVisitor marks the reference parameters that have escaped or
* that are escaping, outside or inside their methods.
*
* @see ReferenceEscapeChecker
* @see ParameterEscapeMarker
* @author Eric Lafortune
*/
public class ParameterEscapedMarker
implements ClassPoolVisitor,
MemberVisitor,
AttributeVisitor,
InstructionVisitor,
ConstantVisitor
{
/*
private static final boolean DEBUG = false;
/*/
private static boolean DEBUG = System.getProperty("pem") != null;
//*/
private final ClassVisitor parameterEscapedMarker =
new AllMethodVisitor(
new AllAttributeVisitor(this));
private final ValueFactory valueFactory = new BasicValueFactory();
private final ReferenceTracingValueFactory tracingValueFactory = new ReferenceTracingValueFactory(valueFactory);
private final PartialEvaluator partialEvaluator =
new PartialEvaluator(tracingValueFactory,
new ParameterTracingInvocationUnit(new BasicInvocationUnit(tracingValueFactory)),
true,
tracingValueFactory);
private final ReferenceEscapeChecker referenceEscapeChecker = new ReferenceEscapeChecker(partialEvaluator, false);
// Parameters and values for visitor methods.
private boolean newEscapes;
private Method referencingMethod;
private int referencingOffset;
private int referencingPopCount;
/**
* Creates a new ParameterModificationMarker.
*/
public ParameterEscapedMarker()
{
}
// Implementations for ClassPoolVisitor.
public void visitClassPool(ClassPool classPool)
{
// Go over all classes and their methods, marking if parameters are
// modified, until no new cases can be found.
do
{
newEscapes = false;
if (DEBUG)
{
System.out.println("ParameterEscapedMarker: new iteration");
}
// Go over all classes and their methods once.
classPool.classesAccept(parameterEscapedMarker);
}
while (newEscapes);
if (DEBUG)
{
classPool.classesAccept(new AllMethodVisitor(this));
}
}
// Implementations for MemberVisitor.
public void visitProgramMethod(ProgramClass programClass, ProgramMethod programMethod)
{
if (DEBUG)
{
System.out.println("ParameterEscapedMarker: [" + programClass.getName() + "." + programMethod.getName(programClass) + programMethod.getDescriptor(programClass) + "]");
int parameterSize =
ClassUtil.internalMethodParameterSize(programMethod.getDescriptor(programClass),
programMethod.getAccessFlags());
for (int index = 0; index < parameterSize; index++)
{
System.out.println(" " +
(hasParameterEscaped(programMethod, index) ? 'e' : '.') +
" P" + index);
}
}
}
// Implementations for AttributeVisitor.
public void visitAnyAttribute(Clazz clazz, Attribute attribute) {}
public void visitCodeAttribute(Clazz clazz, Method method, CodeAttribute codeAttribute)
{
// Evaluate the code.
partialEvaluator.visitCodeAttribute(clazz, method, codeAttribute);
referenceEscapeChecker.visitCodeAttribute(clazz, method, codeAttribute);
// Mark the parameters that are modified from the code.
codeAttribute.instructionsAccept(clazz, method, partialEvaluator.tracedInstructionFilter(this));
}
// Implementations for InstructionVisitor.
public void visitAnyInstruction(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, Instruction instruction) {}
public void visitConstantInstruction(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, ConstantInstruction constantInstruction)
{
switch (constantInstruction.opcode)
{
case Instruction.OP_INVOKEVIRTUAL:
case Instruction.OP_INVOKESPECIAL:
case Instruction.OP_INVOKESTATIC:
case Instruction.OP_INVOKEINTERFACE:
// Mark escaped reference parameters in the invoked method.
referencingMethod = method;
referencingOffset = offset;
referencingPopCount = constantInstruction.stackPopCount(clazz);
clazz.constantPoolEntryAccept(constantInstruction.constantIndex, this);
break;
}
}
// Implementations for ConstantVisitor.
public void visitAnyConstant(Clazz clazz, Constant constant) {}
public void visitAnyMethodrefConstant(Clazz clazz, AnyMethodrefConstant anyMethodrefConstant)
{
Method referencedMethod = (Method)anyMethodrefConstant.referencedMethod;
if (referencedMethod != null &&
MethodOptimizationInfo.getMethodOptimizationInfo(referencedMethod) instanceof ProgramMethodOptimizationInfo)
{
// Mark reference parameters that are passed to the method.
for (int parameterIndex = 0; parameterIndex < referencingPopCount; parameterIndex++)
{
int stackEntryIndex = referencingPopCount - parameterIndex - 1;
TracedStack stackBefore = partialEvaluator.getStackBefore(referencingOffset);
Value stackEntry = stackBefore.getTop(stackEntryIndex);
if (stackEntry.computationalType() == Value.TYPE_REFERENCE)
{
// Has the parameter escaped outside or inside the referencing
// method?
if (hasEscapedBefore(referencingOffset, stackEntryIndex))
{
markParameterEscaped(referencedMethod, parameterIndex);
}
}
}
}
}
// Small utility methods.
/**
* Returns whether any of the producing reference values of the specified
* stack entry before the given instruction offset are escaping or have
* escaped.
*/
private boolean hasEscapedBefore(int instructionOffset,
int stackEntryIndex)
{
TracedStack stackBefore = partialEvaluator.getStackBefore(instructionOffset);
Value stackEntry = stackBefore.getTop(stackEntryIndex);
if (stackEntry.computationalType() == Value.TYPE_REFERENCE)
{
ReferenceValue referenceValue = stackEntry.referenceValue();
// The null reference value may not have a trace value.
if (referenceValue.isNull() != Value.ALWAYS &&
hasEscaped(referenceValue))
{
return true;
}
}
return false;
}
/**
* Returns whether the producing reference value is escaping or has escaped.
*/
private boolean hasEscaped(ReferenceValue referenceValue)
{
TracedReferenceValue tracedReferenceValue = (TracedReferenceValue)referenceValue;
InstructionOffsetValue instructionOffsetValue = tracedReferenceValue.getTraceValue().instructionOffsetValue();
int count = instructionOffsetValue.instructionOffsetCount();
for (int index = 0; index < count; index++)
{
if (instructionOffsetValue.isMethodParameter(index) ?
hasParameterEscaped(referencingMethod, instructionOffsetValue.methodParameter(index)) :
referenceEscapeChecker.isInstanceEscaping(instructionOffsetValue.instructionOffset(index)))
{
return true;
}
}
return false;
}
/**
* Marks the given parameter as escaped from the given method.
*/
private void markParameterEscaped(Method method, int parameterIndex)
{
ProgramMethodOptimizationInfo info = ProgramMethodOptimizationInfo.getProgramMethodOptimizationInfo(method);
if (!info.hasParameterEscaped(parameterIndex))
{
info.setParameterEscaped(parameterIndex);
newEscapes = true;
}
}
/**
* Marks the given parameters as escaped from the given method.
*/
private void markEscapedParameters(Method method, long escapedParameters)
{
ProgramMethodOptimizationInfo info = ProgramMethodOptimizationInfo.getProgramMethodOptimizationInfo(method);
if ((~info.getEscapedParameters() & escapedParameters) != 0)
{
info.updateEscapedParameters(escapedParameters);
newEscapes = true;
}
}
/**
* Returns whether the given parameter is escaped from the given method.
*/
public static boolean hasParameterEscaped(Method method, int parameterIndex)
{
return MethodOptimizationInfo.getMethodOptimizationInfo(method).hasParameterEscaped(parameterIndex);
}
/**
* Returns which parameters are escaped from the given method.
*/
public static long getEscapedParameters(Method method)
{
return MethodOptimizationInfo.getMethodOptimizationInfo(method).getEscapedParameters();
}
}© 2015 - 2024 Weber Informatics LLC | Privacy Policy