| /* |
| * 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.classfile.editor; |
| |
| import proguard.classfile.*; |
| import proguard.classfile.attribute.*; |
| import proguard.classfile.attribute.visitor.AttributeVisitor; |
| 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.*; |
| |
| /** |
| * This AttributeVisitor fixes all inappropriate special/virtual/static/interface |
| * invocations of the code attributes that it visits. |
| * |
| * @author Eric Lafortune |
| */ |
| public class MethodInvocationFixer |
| extends SimplifiedVisitor |
| implements AttributeVisitor, |
| InstructionVisitor, |
| ConstantVisitor, |
| ClassVisitor, |
| MemberVisitor |
| { |
| private static final boolean DEBUG = false; |
| |
| |
| private final CodeAttributeEditor codeAttributeEditor = new CodeAttributeEditor(); |
| |
| // Return values for the visitor methods. |
| private Clazz referencedClass; |
| private Clazz referencedMethodClass; |
| private Member referencedMethod; |
| |
| |
| // Implementations for AttributeVisitor. |
| |
| public void visitAnyAttribute(Clazz clazz, Attribute attribute) {} |
| |
| |
| public void visitCodeAttribute(Clazz clazz, Method method, CodeAttribute codeAttribute) |
| { |
| // Reset the code attribute editor. |
| codeAttributeEditor.reset(codeAttribute.u4codeLength); |
| |
| // Remap the variables of the instructions. |
| codeAttribute.instructionsAccept(clazz, method, this); |
| |
| // Apply the code atribute editor. |
| codeAttributeEditor.visitCodeAttribute(clazz, method, codeAttribute); |
| } |
| |
| |
| // 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) |
| { |
| int constantIndex = constantInstruction.constantIndex; |
| |
| // Get information on the called class and method, if present. |
| referencedMethod = null; |
| |
| clazz.constantPoolEntryAccept(constantIndex, this); |
| |
| // Did we find the called class and method? |
| if (referencedMethod != null) |
| { |
| // Do we need to update the opcode? |
| byte opcode = constantInstruction.opcode; |
| |
| // Is the method static? |
| if ((referencedMethod.getAccessFlags() & ClassConstants.INTERNAL_ACC_STATIC) != 0) |
| { |
| // But is it not a static invocation? |
| if (opcode != InstructionConstants.OP_INVOKESTATIC) |
| { |
| // Replace the invocation by an invokestatic instruction. |
| Instruction replacementInstruction = |
| new ConstantInstruction(InstructionConstants.OP_INVOKESTATIC, |
| constantIndex).shrink(); |
| |
| codeAttributeEditor.replaceInstruction(offset, replacementInstruction); |
| |
| if (DEBUG) |
| { |
| debug(clazz, method, offset, constantInstruction, replacementInstruction); |
| } |
| } |
| } |
| |
| // Is the method private, or an instance initializer? |
| else if ((referencedMethod.getAccessFlags() & ClassConstants.INTERNAL_ACC_PRIVATE) != 0 || |
| referencedMethod.getName(referencedMethodClass).equals(ClassConstants.INTERNAL_METHOD_NAME_INIT)) |
| { |
| // But is it not a special invocation? |
| if (opcode != InstructionConstants.OP_INVOKESPECIAL) |
| { |
| // Replace the invocation by an invokespecial instruction. |
| Instruction replacementInstruction = |
| new ConstantInstruction(InstructionConstants.OP_INVOKESPECIAL, |
| constantIndex).shrink(); |
| |
| codeAttributeEditor.replaceInstruction(offset, replacementInstruction); |
| |
| if (DEBUG) |
| { |
| debug(clazz, method, offset, constantInstruction, replacementInstruction); |
| } |
| } |
| } |
| |
| // Is the method an interface method? |
| else if ((referencedClass.getAccessFlags() & ClassConstants.INTERNAL_ACC_INTERFACE) != 0) |
| { |
| int invokeinterfaceConstant = |
| (ClassUtil.internalMethodParameterSize(referencedMethod.getDescriptor(referencedMethodClass), false)) << 8; |
| |
| // But is it not an interface invocation, or is the parameter |
| // size incorrect? |
| if (opcode != InstructionConstants.OP_INVOKEINTERFACE || |
| constantInstruction.constant != invokeinterfaceConstant) |
| { |
| // Fix the parameter size of the interface invocation. |
| Instruction replacementInstruction = |
| new ConstantInstruction(InstructionConstants.OP_INVOKEINTERFACE, |
| constantIndex, |
| invokeinterfaceConstant).shrink(); |
| |
| codeAttributeEditor.replaceInstruction(offset, replacementInstruction); |
| |
| if (DEBUG) |
| { |
| debug(clazz, method, offset, constantInstruction, replacementInstruction); |
| } |
| } |
| } |
| |
| // The method is not static, private, an instance initializer, or |
| // an interface method. |
| else |
| { |
| // But is it not a virtual invocation (or a special invocation, |
| // but not a super call)? |
| if (opcode != InstructionConstants.OP_INVOKEVIRTUAL && |
| (opcode != InstructionConstants.OP_INVOKESPECIAL || |
| !clazz.extends_(referencedClass))) |
| { |
| // Replace the invocation by an invokevirtual instruction. |
| Instruction replacementInstruction = |
| new ConstantInstruction(InstructionConstants.OP_INVOKEVIRTUAL, |
| constantIndex).shrink(); |
| |
| codeAttributeEditor.replaceInstruction(offset, replacementInstruction); |
| |
| if (DEBUG) |
| { |
| debug(clazz, method, offset, constantInstruction, replacementInstruction); |
| } |
| } |
| } |
| } |
| } |
| |
| |
| // Implementations for ConstantVisitor. |
| |
| public void visitAnyConstant(Clazz clazz, Constant constant) {} |
| |
| |
| public void visitAnyMethodrefConstant(Clazz clazz, RefConstant refConstant) |
| { |
| // Check if this is an interface method. Note that we're interested in |
| // the class of the method reference, not in the class in which the |
| // method was actually found. |
| //refConstant.referencedClassAccept(this); |
| clazz.constantPoolEntryAccept(refConstant.u2classIndex, this); |
| |
| // Get the referenced access flags and names. |
| refConstant.referencedMemberAccept(this); |
| } |
| |
| |
| public void visitClassConstant(Clazz clazz, ClassConstant classConstant) |
| { |
| // Check if this is an interface class. |
| classConstant.referencedClassAccept(this); |
| } |
| |
| |
| // Implementations for ClassVisitor. |
| |
| public void visitAnyClass(Clazz clazz) |
| { |
| // Remember the referenced class. |
| referencedClass = clazz; |
| } |
| |
| |
| // Implementations for MemberVisitor. |
| |
| public void visitAnyMember(Clazz clazz, Member member) |
| { |
| // Remember the referenced method. |
| referencedMethodClass = clazz; |
| referencedMethod = member; |
| } |
| |
| |
| // Small utility methods. |
| |
| private void debug(Clazz clazz, |
| Method method, |
| int offset, |
| ConstantInstruction constantInstruction, |
| Instruction replacementInstruction) |
| { |
| System.out.println("MethodInvocationFixer:"); |
| System.out.println(" Class = "+clazz.getName()); |
| System.out.println(" Method = "+method.getName(clazz)+method.getDescriptor(clazz)); |
| System.out.println(" Instruction = "+constantInstruction.toString(offset)); |
| System.out.println(" -> Class = "+referencedClass); |
| System.out.println(" Method = "+referencedMethod); |
| if ((referencedClass.getAccessFlags() & ClassConstants.INTERNAL_ACC_INTERFACE) != 0) |
| { |
| System.out.println(" Parameter size = "+(ClassUtil.internalMethodParameterSize(referencedMethod.getDescriptor(referencedMethodClass), false))); |
| } |
| System.out.println(" Replacement instruction = "+replacementInstruction.toString(offset)); |
| } |
| } |