proguard.optimize.info.EscapingClassMarker Maven / Gradle / Ivy
/*
* ProGuard -- shrinking, optimization, obfuscation, and preverification
* of Java bytecode.
*
* Copyright (c) 2002-2018 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.AttributeVisitor;
import proguard.classfile.instruction.Instruction;
import proguard.classfile.instruction.visitor.InstructionVisitor;
import proguard.classfile.util.*;
import proguard.classfile.visitor.ClassVisitor;
import proguard.evaluation.*;
import proguard.evaluation.value.*;
import proguard.optimize.evaluation.*;
/**
* This AttributeVisitor marks the classes that are escaping from the visited
* code attributes.
*
* @see ReferenceEscapeChecker
* @author Eric Lafortune
*/
public class EscapingClassMarker
extends SimplifiedVisitor
implements AttributeVisitor,
InstructionVisitor,
ClassVisitor
{
//*
private static final boolean DEBUG = false;
/*/
private static boolean DEBUG = System.getProperty("ecm") != null;
//*/
private final PartialEvaluator partialEvaluator;
private final boolean runPartialEvaluator;
private final ReferenceEscapeChecker referenceEscapeChecker;
private final boolean runReferenceEscapeChecker;
/**
* Creates a new EscapingClassMarker.
*/
public EscapingClassMarker()
{
// We need typed references.
this(new TypedReferenceValueFactory());
}
/**
* Creates a new EscapingClassMarker.
*/
public EscapingClassMarker(ValueFactory valueFactory)
{
this(valueFactory,
new ReferenceTracingValueFactory(valueFactory));
}
/**
* Creates a new EscapingClassMarker.
*/
public EscapingClassMarker(ValueFactory valueFactory,
ReferenceTracingValueFactory tracingValueFactory)
{
this(new PartialEvaluator(tracingValueFactory,
new ReferenceTracingInvocationUnit(new BasicInvocationUnit(tracingValueFactory)),
true,
tracingValueFactory),
true);
}
/**
* Creates a new EscapingClassMarker.
*/
public EscapingClassMarker(PartialEvaluator partialEvaluator,
boolean runPartialEvaluator)
{
this(partialEvaluator,
runPartialEvaluator,
new ReferenceEscapeChecker(partialEvaluator, false),
true);
}
/**
* Creates a new EscapingClassMarker.
*/
public EscapingClassMarker(PartialEvaluator partialEvaluator,
boolean runPartialEvaluator,
ReferenceEscapeChecker referenceEscapeChecker,
boolean runReferenceEscapeChecker)
{
this.partialEvaluator = partialEvaluator;
this.runPartialEvaluator = runPartialEvaluator;
this.referenceEscapeChecker = referenceEscapeChecker;
this.runReferenceEscapeChecker = runReferenceEscapeChecker;
}
// Implementations for AttributeVisitor.
public void visitAnyAttribute(Clazz clazz, Attribute attribute) {}
public void visitCodeAttribute(Clazz clazz, Method method, CodeAttribute codeAttribute)
{
// Evaluate the code.
if (runPartialEvaluator)
{
partialEvaluator.visitCodeAttribute(clazz, method, codeAttribute);
}
if (runReferenceEscapeChecker)
{
referenceEscapeChecker.visitCodeAttribute(clazz, method, codeAttribute);
}
// Mark all escaping classes.
codeAttribute.instructionsAccept(clazz,
method,
partialEvaluator.tracedInstructionFilter(this));
}
// Implementations for InstructionVisitor.
public void visitAnyInstruction(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, Instruction instruction)
{
// Does the instruction push a value that escapes?
// We'll also count values that are returned, since they may be
// downcast and the downcast type may escape in some calling
// method.
// TODO: Refine check: is a value is downcast to an escaping class, while it is being returned?
if (instruction.stackPushCount(clazz) == 1 &&
(referenceEscapeChecker.isInstanceEscaping(offset) ||
referenceEscapeChecker.isInstanceReturned(offset)))
{
TracedStack stackAfter = partialEvaluator.getStackAfter(offset);
Value stackEntry = stackAfter.getTop(0);
// Is it really a reference type?
if (stackEntry.computationalType() == Value.TYPE_REFERENCE)
{
// Is it a plain class reference type?
ReferenceValue referenceValue = stackEntry.referenceValue();
if (referenceValue.isNull() != Value.ALWAYS &&
!ClassUtil.isInternalArrayType(referenceValue.getType()))
{
// Do we know the class?
Clazz referencedClass = referenceValue.getReferencedClass();
if (referencedClass != null)
{
if (DEBUG)
{
System.out.println("EscapingClassMarker: ["+clazz.getName()+"."+method.getName(clazz)+method.getDescriptor(clazz)+"]: "+instruction.toString(offset)+" pushes escaping ["+referencedClass.getName()+"]");
}
// Mark it, along with its superclasses.
referencedClass.hierarchyAccept(true, true, true, false, this);
}
}
}
}
}
// Implementations for ClassVisitor.
public void visitLibraryClass(LibraryClass libraryClass) {}
public void visitProgramClass(ProgramClass programClass)
{
markClassEscaping(programClass);
}
// Small utility methods.
/**
* Marks the given class as escaping.
*/
private void markClassEscaping(Clazz clazz)
{
ClassOptimizationInfo info = ProgramClassOptimizationInfo.getClassOptimizationInfo(clazz);
if (info instanceof ProgramClassOptimizationInfo)
{
((ProgramClassOptimizationInfo)info).setEscaping();
}
}
/**
* Returns whether the given class is escaping.
*/
public static boolean isClassEscaping(Clazz clazz)
{
return ClassOptimizationInfo.getClassOptimizationInfo(clazz).isEscaping();
}
}
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