| /* |
| * ProGuard -- shrinking, optimization, obfuscation, and preverification |
| * of Java bytecode. |
| * |
| * Copyright (c) 2002-2009 Eric Lafortune (eric@graphics.cornell.edu) |
| * |
| * 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.instruction.*; |
| import proguard.classfile.instruction.visitor.InstructionVisitor; |
| import proguard.classfile.attribute.visitor.AttributeVisitor; |
| import proguard.classfile.attribute.*; |
| import proguard.classfile.util.*; |
| import proguard.classfile.visitor.MemberVisitor; |
| import proguard.optimize.evaluation.PartialEvaluator; |
| import proguard.evaluation.value.*; |
| |
| /** |
| * This MemberVisitor counts the parameters and marks the used parameters |
| * of the methods that it visits. It also marks the 'this' parameters of |
| * methods that have hierarchies. |
| * |
| * @author Eric Lafortune |
| */ |
| public class ParameterUsageMarker |
| extends SimplifiedVisitor |
| implements MemberVisitor, |
| AttributeVisitor, |
| InstructionVisitor |
| { |
| private static final boolean DEBUG = false; |
| |
| |
| private final boolean markThisParameter; |
| private final boolean markAllParameters; |
| private final PartialEvaluator partialEvaluator = new PartialEvaluator(); |
| |
| |
| /** |
| * Creates a new ParameterUsageMarker. |
| */ |
| public ParameterUsageMarker() |
| { |
| this(false, false); |
| } |
| |
| |
| /** |
| * Creates a new ParameterUsageMarker that optionally marks all parameters. |
| * @param markThisParameter specifies whether all 'this' parameters should |
| * be marked as being used. |
| * @param markAllParameters specifies whether all other parameters should |
| * be marked as being used. |
| */ |
| public ParameterUsageMarker(boolean markThisParameter, |
| boolean markAllParameters) |
| { |
| this.markThisParameter = markThisParameter; |
| this.markAllParameters = markAllParameters; |
| } |
| |
| |
| // Implementations for MemberVisitor. |
| |
| public void visitProgramMethod(ProgramClass programClass, ProgramMethod programMethod) |
| { |
| int parameterSize = |
| ClassUtil.internalMethodParameterSize(programMethod.getDescriptor(programClass), |
| programMethod.getAccessFlags()); |
| |
| if (parameterSize > 0) |
| { |
| int accessFlags = programMethod.getAccessFlags(); |
| |
| // Must we mark the 'this' parameter? |
| if (markThisParameter && |
| (accessFlags & ClassConstants.INTERNAL_ACC_STATIC) == 0) |
| { |
| // Mark the 'this' parameter. |
| markParameterUsed(programMethod, 0); |
| } |
| |
| // Must we mark all other parameters? |
| if (markAllParameters) |
| { |
| // Mark all parameters, without the 'this' parameter. |
| markUsedParameters(programMethod, |
| (accessFlags & ClassConstants.INTERNAL_ACC_STATIC) != 0 ? |
| -1L : -2L); |
| } |
| |
| // Is it a native method? |
| if ((accessFlags & ClassConstants.INTERNAL_ACC_NATIVE) != 0) |
| { |
| // Mark all parameters. |
| markUsedParameters(programMethod, -1L); |
| } |
| |
| // Is it an abstract method? |
| else if ((accessFlags & ClassConstants.INTERNAL_ACC_ABSTRACT) != 0) |
| { |
| // Mark the 'this' parameter. |
| markParameterUsed(programMethod, 0); |
| } |
| |
| // Is it a non-native, concrete method? |
| else |
| { |
| // Is the method not static, but synchronized, or can it have |
| // other implementations, or is it a class instance initializer? |
| if ((accessFlags & ClassConstants.INTERNAL_ACC_STATIC) == 0 && |
| ((accessFlags & ClassConstants.INTERNAL_ACC_SYNCHRONIZED) != 0 || |
| programClass.mayHaveImplementations(programMethod) || |
| programMethod.getName(programClass).equals(ClassConstants.INTERNAL_METHOD_NAME_INIT))) |
| { |
| // Mark the 'this' parameter. |
| markParameterUsed(programMethod, 0); |
| } |
| |
| // Mark the parameters that are used by the code. |
| programMethod.attributesAccept(programClass, this); |
| } |
| |
| if (DEBUG) |
| { |
| System.out.print("ParameterUsageMarker: ["+programClass.getName() +"."+programMethod.getName(programClass)+programMethod.getDescriptor(programClass)+"]: "); |
| for (int index = 0; index < parameterSize; index++) |
| { |
| System.out.print(isParameterUsed(programMethod, index) ? '+' : '-'); |
| } |
| System.out.println(); |
| } |
| |
| } |
| |
| // Set the parameter size. |
| setParameterSize(programMethod, parameterSize); |
| } |
| |
| |
| public void visitLibraryMethod(LibraryClass libraryClass, LibraryMethod libraryMethod) |
| { |
| // Can the method have other implementations? |
| if (libraryClass.mayHaveImplementations(libraryMethod)) |
| { |
| // All implementations must keep all parameters of this method, |
| // including the 'this' parameter. |
| markUsedParameters(libraryMethod, -1L); |
| } |
| } |
| |
| |
| // 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); |
| |
| // Mark the parameters that are used by the code. |
| codeAttribute.instructionsAccept(clazz, method, this); |
| } |
| |
| |
| // Implementations for InstructionVisitor. |
| |
| public void visitAnyInstruction(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, Instruction instruction) {} |
| |
| |
| public void visitVariableInstruction(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, VariableInstruction variableInstruction) |
| { |
| if (partialEvaluator.isTraced(offset) && |
| variableInstruction.isLoad()) |
| { |
| int parameterIndex = variableInstruction.variableIndex; |
| if (parameterIndex < codeAttribute.u2maxLocals) |
| { |
| Value producer = |
| partialEvaluator.getVariablesBefore(offset).getProducerValue(parameterIndex); |
| if (producer != null && |
| producer.instructionOffsetValue().contains(PartialEvaluator.AT_METHOD_ENTRY)) |
| { |
| // Mark the variable. |
| markParameterUsed(method, parameterIndex); |
| |
| // Account for Category 2 instructions, which take up two entries. |
| if (variableInstruction.isCategory2()) |
| { |
| markParameterUsed(method, parameterIndex + 1); |
| } |
| } |
| } |
| } |
| } |
| |
| |
| // Small utility methods. |
| |
| /** |
| * Sets the total size of the parameters. |
| */ |
| private static void setParameterSize(Method method, int parameterSize) |
| { |
| MethodOptimizationInfo info = MethodOptimizationInfo.getMethodOptimizationInfo(method); |
| if (info != null) |
| { |
| info.setParameterSize(parameterSize); |
| } |
| } |
| |
| |
| /** |
| * Returns the total size of the parameters. |
| */ |
| public static int getParameterSize(Method method) |
| { |
| MethodOptimizationInfo info = MethodOptimizationInfo.getMethodOptimizationInfo(method); |
| return info != null ? info.getParameterSize() : 0; |
| } |
| |
| |
| /** |
| * Marks the given parameter as being used. |
| */ |
| public static void markParameterUsed(Method method, int variableIndex) |
| { |
| MethodOptimizationInfo info = MethodOptimizationInfo.getMethodOptimizationInfo(method); |
| if (info != null) |
| { |
| info.setParameterUsed(variableIndex); |
| } |
| } |
| |
| |
| /** |
| * Marks the given parameters as being used. |
| */ |
| public static void markUsedParameters(Method method, long usedParameters) |
| { |
| MethodOptimizationInfo info = MethodOptimizationInfo.getMethodOptimizationInfo(method); |
| if (info != null) |
| { |
| info.setUsedParameters(info.getUsedParameters() | usedParameters); |
| } |
| } |
| |
| |
| /** |
| * Returns whether the given parameter is being used. |
| */ |
| public static boolean isParameterUsed(Method method, int variableIndex) |
| { |
| MethodOptimizationInfo info = MethodOptimizationInfo.getMethodOptimizationInfo(method); |
| return info == null || |
| info.isParameterUsed(variableIndex); |
| } |
| |
| |
| /** |
| * Returns which parameters are being used. |
| */ |
| public static long getUsedParameters(Method method) |
| { |
| MethodOptimizationInfo info = MethodOptimizationInfo.getMethodOptimizationInfo(method); |
| return info != null ? info.getUsedParameters() : -1L; |
| } |
| } |