| /* |
| * 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.preverification.*; |
| import proguard.classfile.attribute.preverification.visitor.*; |
| import proguard.classfile.attribute.visitor.*; |
| import proguard.classfile.instruction.*; |
| import proguard.classfile.instruction.visitor.InstructionVisitor; |
| import proguard.classfile.util.SimplifiedVisitor; |
| import proguard.classfile.visitor.ClassPrinter; |
| |
| /** |
| * This AttributeVisitor accumulates specified changes to code, and then applies |
| * these accumulated changes to the code attributes that it visits. |
| * |
| * @author Eric Lafortune |
| */ |
| public class CodeAttributeEditor |
| extends SimplifiedVisitor |
| implements AttributeVisitor, |
| InstructionVisitor, |
| ExceptionInfoVisitor, |
| StackMapFrameVisitor, |
| VerificationTypeVisitor, |
| LineNumberInfoVisitor, |
| LocalVariableInfoVisitor, |
| LocalVariableTypeInfoVisitor |
| { |
| //* |
| private static final boolean DEBUG = false; |
| /*/ |
| private static boolean DEBUG = true; |
| //*/ |
| |
| private boolean updateFrameSizes; |
| |
| private int codeLength; |
| private boolean modified; |
| private boolean simple; |
| |
| /*private*/public Instruction[] preInsertions = new Instruction[ClassConstants.TYPICAL_CODE_LENGTH]; |
| /*private*/public Instruction[] replacements = new Instruction[ClassConstants.TYPICAL_CODE_LENGTH]; |
| /*private*/public Instruction[] postInsertions = new Instruction[ClassConstants.TYPICAL_CODE_LENGTH]; |
| /*private*/public boolean[] deleted = new boolean[ClassConstants.TYPICAL_CODE_LENGTH]; |
| |
| private int[] instructionOffsetMap = new int[ClassConstants.TYPICAL_CODE_LENGTH]; |
| private int newOffset; |
| private boolean lengthIncreased; |
| |
| private int expectedStackMapFrameOffset; |
| |
| private final StackSizeUpdater stackSizeUpdater = new StackSizeUpdater(); |
| private final VariableSizeUpdater variableSizeUpdater = new VariableSizeUpdater(); |
| private final InstructionWriter instructionWriter = new InstructionWriter(); |
| |
| |
| public CodeAttributeEditor() |
| { |
| this(true); |
| } |
| |
| |
| public CodeAttributeEditor(boolean updateFrameSizes) |
| { |
| this.updateFrameSizes = updateFrameSizes; |
| } |
| |
| |
| /** |
| * Resets the accumulated code changes. |
| * @param codeLength the length of the code that will be edited next. |
| */ |
| public void reset(int codeLength) |
| { |
| this.codeLength = codeLength; |
| |
| // Try to reuse the previous arrays. |
| if (preInsertions.length < codeLength) |
| { |
| preInsertions = new Instruction[codeLength]; |
| replacements = new Instruction[codeLength]; |
| postInsertions = new Instruction[codeLength]; |
| deleted = new boolean[codeLength]; |
| } |
| else |
| { |
| for (int index = 0; index < codeLength; index++) |
| { |
| preInsertions[index] = null; |
| replacements[index] = null; |
| postInsertions[index] = null; |
| deleted[index] = false; |
| } |
| } |
| |
| modified = false; |
| simple = true; |
| |
| } |
| |
| |
| /** |
| * Remembers to place the given instruction right before the instruction |
| * at the given offset. |
| * @param instructionOffset the offset of the instruction. |
| * @param instruction the new instruction. |
| */ |
| public void insertBeforeInstruction(int instructionOffset, Instruction instruction) |
| { |
| if (instructionOffset < 0 || |
| instructionOffset >= codeLength) |
| { |
| throw new IllegalArgumentException("Invalid instruction offset ["+instructionOffset+"] in code with length ["+codeLength+"]"); |
| } |
| |
| preInsertions[instructionOffset] = instruction; |
| |
| modified = true; |
| simple = false; |
| |
| } |
| |
| |
| /** |
| * Remembers to place the given instructions right before the instruction |
| * at the given offset. |
| * @param instructionOffset the offset of the instruction. |
| * @param instructions the new instructions. |
| */ |
| public void insertBeforeInstruction(int instructionOffset, Instruction[] instructions) |
| { |
| if (instructionOffset < 0 || |
| instructionOffset >= codeLength) |
| { |
| throw new IllegalArgumentException("Invalid instruction offset ["+instructionOffset+"] in code with length ["+codeLength+"]"); |
| } |
| |
| preInsertions[instructionOffset] = new CompositeInstruction(instructions); |
| |
| modified = true; |
| simple = false; |
| |
| } |
| |
| |
| /** |
| * Remembers to replace the instruction at the given offset by the given |
| * instruction. |
| * @param instructionOffset the offset of the instruction to be replaced. |
| * @param instruction the new instruction. |
| */ |
| public void replaceInstruction(int instructionOffset, Instruction instruction) |
| { |
| if (instructionOffset < 0 || |
| instructionOffset >= codeLength) |
| { |
| throw new IllegalArgumentException("Invalid instruction offset ["+instructionOffset+"] in code with length ["+codeLength+"]"); |
| } |
| |
| replacements[instructionOffset] = instruction; |
| |
| modified = true; |
| } |
| |
| |
| /** |
| * Remembers to replace the instruction at the given offset by the given |
| * instructions. |
| * @param instructionOffset the offset of the instruction to be replaced. |
| * @param instructions the new instructions. |
| */ |
| public void replaceInstruction(int instructionOffset, Instruction[] instructions) |
| { |
| if (instructionOffset < 0 || |
| instructionOffset >= codeLength) |
| { |
| throw new IllegalArgumentException("Invalid instruction offset ["+instructionOffset+"] in code with length ["+codeLength+"]"); |
| } |
| |
| replacements[instructionOffset] = new CompositeInstruction(instructions); |
| |
| modified = true; |
| } |
| |
| |
| /** |
| * Remembers to place the given instruction right after the instruction |
| * at the given offset. |
| * @param instructionOffset the offset of the instruction. |
| * @param instruction the new instruction. |
| */ |
| public void insertAfterInstruction(int instructionOffset, Instruction instruction) |
| { |
| if (instructionOffset < 0 || |
| instructionOffset >= codeLength) |
| { |
| throw new IllegalArgumentException("Invalid instruction offset ["+instructionOffset+"] in code with length ["+codeLength+"]"); |
| } |
| |
| postInsertions[instructionOffset] = instruction; |
| |
| modified = true; |
| simple = false; |
| } |
| |
| |
| /** |
| * Remembers to place the given instructions right after the instruction |
| * at the given offset. |
| * @param instructionOffset the offset of the instruction. |
| * @param instructions the new instructions. |
| */ |
| public void insertAfterInstruction(int instructionOffset, Instruction[] instructions) |
| { |
| if (instructionOffset < 0 || |
| instructionOffset >= codeLength) |
| { |
| throw new IllegalArgumentException("Invalid instruction offset ["+instructionOffset+"] in code with length ["+codeLength+"]"); |
| } |
| |
| postInsertions[instructionOffset] = new CompositeInstruction(instructions); |
| |
| modified = true; |
| simple = false; |
| } |
| |
| |
| /** |
| * Remembers to delete the instruction at the given offset. |
| * @param instructionOffset the offset of the instruction to be deleted. |
| */ |
| public void deleteInstruction(int instructionOffset) |
| { |
| if (instructionOffset < 0 || |
| instructionOffset >= codeLength) |
| { |
| throw new IllegalArgumentException("Invalid instruction offset ["+instructionOffset+"] in code with length ["+codeLength+"]"); |
| } |
| |
| deleted[instructionOffset] = true; |
| |
| modified = true; |
| simple = false; |
| } |
| |
| |
| /** |
| * Remembers not to delete the instruction at the given offset. |
| * @param instructionOffset the offset of the instruction not to be deleted. |
| */ |
| public void undeleteInstruction(int instructionOffset) |
| { |
| if (instructionOffset < 0 || |
| instructionOffset >= codeLength) |
| { |
| throw new IllegalArgumentException("Invalid instruction offset ["+instructionOffset+"] in code with length ["+codeLength+"]"); |
| } |
| |
| deleted[instructionOffset] = false; |
| } |
| |
| |
| /** |
| * Returns whether the instruction at the given offset has been modified |
| * in any way. |
| */ |
| public boolean isModified(int instructionOffset) |
| { |
| return preInsertions[instructionOffset] != null || |
| replacements[instructionOffset] != null || |
| postInsertions[instructionOffset] != null || |
| deleted[instructionOffset]; |
| } |
| |
| |
| // Implementations for AttributeVisitor. |
| |
| public void visitAnyAttribute(Clazz clazz, Attribute attribute) {} |
| |
| |
| public void visitCodeAttribute(Clazz clazz, Method method, CodeAttribute codeAttribute) |
| { |
| // DEBUG = |
| // clazz.getName().equals("abc/Def") && |
| // method.getName(clazz).equals("abc"); |
| |
| // TODO: Remove this when the code has stabilized. |
| // Catch any unexpected exceptions from the actual visiting method. |
| try |
| { |
| // Process the code. |
| visitCodeAttribute0(clazz, method, codeAttribute); |
| } |
| catch (RuntimeException ex) |
| { |
| System.err.println("Unexpected error while editing code:"); |
| System.err.println(" Class = ["+clazz.getName()+"]"); |
| System.err.println(" Method = ["+method.getName(clazz)+method.getDescriptor(clazz)+"]"); |
| System.err.println(" Exception = ["+ex.getClass().getName()+"] ("+ex.getMessage()+")"); |
| |
| throw ex; |
| } |
| } |
| |
| |
| public void visitCodeAttribute0(Clazz clazz, Method method, CodeAttribute codeAttribute) |
| { |
| if (DEBUG) |
| { |
| System.out.println("CodeAttributeEditor: ["+clazz.getName()+"."+method.getName(clazz)+"]"); |
| } |
| |
| // Avoid doing any work if nothing is changing anyway. |
| if (!modified) |
| { |
| return; |
| } |
| |
| // Check if we can perform a faster simple replacement of instructions. |
| if (canPerformSimpleReplacements(codeAttribute)) |
| { |
| // Simply overwrite the instructions. |
| performSimpleReplacements(codeAttribute); |
| |
| // Update the maximum stack size and local variable frame size. |
| updateFrameSizes(clazz, method, codeAttribute); |
| } |
| else |
| { |
| // Move and remap the instructions. |
| codeAttribute.u4codeLength = |
| updateInstructions(clazz, method, codeAttribute); |
| |
| // Remap the exception table. |
| codeAttribute.exceptionsAccept(clazz, method, this); |
| |
| // Remove exceptions with empty code blocks. |
| codeAttribute.u2exceptionTableLength = |
| removeEmptyExceptions(codeAttribute.exceptionTable, |
| codeAttribute.u2exceptionTableLength); |
| |
| // Update the maximum stack size and local variable frame size. |
| updateFrameSizes(clazz, method, codeAttribute); |
| |
| // Remap the line number table and the local variable table. |
| codeAttribute.attributesAccept(clazz, method, this); |
| |
| // Make sure instructions are widened if necessary. |
| instructionWriter.visitCodeAttribute(clazz, method, codeAttribute); |
| } |
| } |
| |
| |
| private void updateFrameSizes(Clazz clazz, Method method, CodeAttribute codeAttribute) |
| { |
| if (updateFrameSizes) |
| { |
| stackSizeUpdater.visitCodeAttribute(clazz, method, codeAttribute); |
| variableSizeUpdater.visitCodeAttribute(clazz, method, codeAttribute); |
| } |
| } |
| |
| |
| public void visitStackMapAttribute(Clazz clazz, Method method, CodeAttribute codeAttribute, StackMapAttribute stackMapAttribute) |
| { |
| // Remap all stack map entries. |
| expectedStackMapFrameOffset = -1; |
| stackMapAttribute.stackMapFramesAccept(clazz, method, codeAttribute, this); |
| } |
| |
| |
| public void visitStackMapTableAttribute(Clazz clazz, Method method, CodeAttribute codeAttribute, StackMapTableAttribute stackMapTableAttribute) |
| { |
| // Remap all stack map table entries. |
| expectedStackMapFrameOffset = 0; |
| stackMapTableAttribute.stackMapFramesAccept(clazz, method, codeAttribute, this); |
| } |
| |
| |
| public void visitLineNumberTableAttribute(Clazz clazz, Method method, CodeAttribute codeAttribute, LineNumberTableAttribute lineNumberTableAttribute) |
| { |
| // Remap all line number table entries. |
| lineNumberTableAttribute.lineNumbersAccept(clazz, method, codeAttribute, this); |
| |
| // Remove line numbers with empty code blocks. |
| lineNumberTableAttribute.u2lineNumberTableLength = |
| removeEmptyLineNumbers(lineNumberTableAttribute.lineNumberTable, |
| lineNumberTableAttribute.u2lineNumberTableLength, |
| codeAttribute.u4codeLength); |
| } |
| |
| |
| public void visitLocalVariableTableAttribute(Clazz clazz, Method method, CodeAttribute codeAttribute, LocalVariableTableAttribute localVariableTableAttribute) |
| { |
| // Remap all local variable table entries. |
| localVariableTableAttribute.localVariablesAccept(clazz, method, codeAttribute, this); |
| |
| // Remove local variables with empty code blocks. |
| localVariableTableAttribute.u2localVariableTableLength = |
| removeEmptyLocalVariables(localVariableTableAttribute.localVariableTable, |
| localVariableTableAttribute.u2localVariableTableLength, |
| codeAttribute.u2maxLocals); |
| } |
| |
| |
| public void visitLocalVariableTypeTableAttribute(Clazz clazz, Method method, CodeAttribute codeAttribute, LocalVariableTypeTableAttribute localVariableTypeTableAttribute) |
| { |
| // Remap all local variable table entries. |
| localVariableTypeTableAttribute.localVariablesAccept(clazz, method, codeAttribute, this); |
| |
| // Remove local variables with empty code blocks. |
| localVariableTypeTableAttribute.u2localVariableTypeTableLength = |
| removeEmptyLocalVariableTypes(localVariableTypeTableAttribute.localVariableTypeTable, |
| localVariableTypeTableAttribute.u2localVariableTypeTableLength, |
| codeAttribute.u2maxLocals); |
| } |
| |
| |
| /** |
| * Checks if it is possible to modifies the given code without having to |
| * update any offsets. |
| * @param codeAttribute the code to be changed. |
| * @return the new code length. |
| */ |
| private boolean canPerformSimpleReplacements(CodeAttribute codeAttribute) |
| { |
| if (!simple) |
| { |
| return false; |
| } |
| |
| byte[] code = codeAttribute.code; |
| int codeLength = codeAttribute.u4codeLength; |
| |
| // Go over all replacement instructions. |
| for (int offset = 0; offset < codeLength; offset++) |
| { |
| // Check if the replacement instruction, if any, has a different |
| // length than the original instruction. |
| Instruction replacementInstruction = replacements[offset]; |
| if (replacementInstruction != null && |
| replacementInstruction.length(offset) != |
| InstructionFactory.create(code, offset).length(offset)) |
| { |
| return false; |
| } |
| } |
| |
| return true; |
| } |
| |
| |
| /** |
| * Modifies the given code without updating any offsets. |
| * @param codeAttribute the code to be changed. |
| */ |
| private void performSimpleReplacements(CodeAttribute codeAttribute) |
| { |
| int codeLength = codeAttribute.u4codeLength; |
| |
| // Go over all replacement instructions. |
| for (int offset = 0; offset < codeLength; offset++) |
| { |
| // Overwrite the original instruction with the replacement |
| // instruction if any. |
| Instruction replacementInstruction = replacements[offset]; |
| if (replacementInstruction != null) |
| { |
| replacementInstruction.write(codeAttribute, offset); |
| |
| if (DEBUG) |
| { |
| System.out.println(" Replaced "+replacementInstruction.toString(newOffset)); |
| } |
| } |
| } |
| } |
| |
| |
| /** |
| * Modifies the given code based on the previously specified changes. |
| * @param clazz the class file of the code to be changed. |
| * @param method the method of the code to be changed. |
| * @param codeAttribute the code to be changed. |
| * @return the new code length. |
| */ |
| private int updateInstructions(Clazz clazz, |
| Method method, |
| CodeAttribute codeAttribute) |
| { |
| byte[] oldCode = codeAttribute.code; |
| int oldLength = codeAttribute.u4codeLength; |
| |
| // Make sure there is a sufficiently large instruction offset map. |
| if (instructionOffsetMap.length < oldLength + 1) |
| { |
| instructionOffsetMap = new int[oldLength + 1]; |
| } |
| |
| // Fill out the instruction offset map. |
| int newLength = mapInstructions(oldCode, |
| oldLength); |
| |
| // Create a new code array if necessary. |
| if (lengthIncreased) |
| { |
| codeAttribute.code = new byte[newLength]; |
| } |
| |
| // Prepare for possible widening of instructions. |
| instructionWriter.reset(newLength); |
| |
| // Move the instructions into the new code array. |
| moveInstructions(clazz, |
| method, |
| codeAttribute, |
| oldCode, |
| oldLength); |
| |
| // We can return the new length. |
| return newLength; |
| } |
| |
| |
| /** |
| * Fills out the instruction offset map for the given code block. |
| * @param oldCode the instructions to be moved. |
| * @param oldLength the code length. |
| * @return the new code length. |
| */ |
| private int mapInstructions(byte[] oldCode, int oldLength) |
| { |
| // Start mapping instructions at the beginning. |
| newOffset = 0; |
| lengthIncreased = false; |
| |
| int oldOffset = 0; |
| do |
| { |
| // Get the next instruction. |
| Instruction instruction = InstructionFactory.create(oldCode, oldOffset); |
| |
| // Compute the mapping of the instruction. |
| mapInstruction(oldOffset, instruction); |
| |
| oldOffset += instruction.length(oldOffset); |
| |
| if (newOffset > oldOffset) |
| { |
| lengthIncreased = true; |
| } |
| } |
| while (oldOffset < oldLength); |
| |
| // Also add an entry for the first offset after the code. |
| instructionOffsetMap[oldOffset] = newOffset; |
| |
| return newOffset; |
| } |
| |
| |
| /** |
| * Fills out the instruction offset map for the given instruction. |
| * @param oldOffset the instruction's old offset. |
| * @param instruction the instruction to be moved. |
| */ |
| private void mapInstruction(int oldOffset, |
| Instruction instruction) |
| { |
| instructionOffsetMap[oldOffset] = newOffset; |
| |
| // Account for the pre-inserted instruction, if any. |
| Instruction preInstruction = preInsertions[oldOffset]; |
| if (preInstruction != null) |
| { |
| newOffset += preInstruction.length(newOffset); |
| } |
| |
| // Account for the replacement instruction, or for the current |
| // instruction, if it shouldn't be deleted. |
| Instruction replacementInstruction = replacements[oldOffset]; |
| if (replacementInstruction != null) |
| { |
| newOffset += replacementInstruction.length(newOffset); |
| } |
| else if (!deleted[oldOffset]) |
| { |
| // Note that the instruction's length may change at its new offset, |
| // e.g. if it is a switch instruction. |
| newOffset += instruction.length(newOffset); |
| } |
| |
| // Account for the post-inserted instruction, if any. |
| Instruction postInstruction = postInsertions[oldOffset]; |
| if (postInstruction != null) |
| { |
| newOffset += postInstruction.length(newOffset); |
| } |
| } |
| |
| |
| /** |
| * Moves the given code block to the new offsets. |
| * @param clazz the class file of the code to be changed. |
| * @param method the method of the code to be changed. |
| * @param codeAttribute the code to be changed. |
| * @param oldCode the original code to be moved. |
| * @param oldLength the original code length. |
| */ |
| private void moveInstructions(Clazz clazz, |
| Method method, |
| CodeAttribute codeAttribute, |
| byte[] oldCode, |
| int oldLength) |
| { |
| // Start writing instructions at the beginning. |
| newOffset = 0; |
| |
| int oldOffset = 0; |
| do |
| { |
| // Get the next instruction. |
| Instruction instruction = InstructionFactory.create(oldCode, oldOffset); |
| |
| // Move the instruction to its new offset. |
| moveInstruction(clazz, |
| method, |
| codeAttribute, |
| oldOffset, |
| instruction); |
| |
| oldOffset += instruction.length(oldOffset); |
| } |
| while (oldOffset < oldLength); |
| } |
| |
| |
| /** |
| * Moves the given instruction to its new offset. |
| * @param clazz the class file of the code to be changed. |
| * @param method the method of the code to be changed. |
| * @param codeAttribute the code to be changed. |
| * @param oldOffset the original instruction offset. |
| * @param instruction the original instruction. |
| */ |
| private void moveInstruction(Clazz clazz, |
| Method method, |
| CodeAttribute codeAttribute, |
| int oldOffset, |
| Instruction instruction) |
| { |
| // Remap and insert the pre-inserted instruction, if any. |
| Instruction preInstruction = preInsertions[oldOffset]; |
| if (preInstruction != null) |
| { |
| if (DEBUG) |
| { |
| System.out.println(" Pre-inserted "+preInstruction.toString(newOffset)); |
| } |
| |
| // Remap the instruction. |
| preInstruction.accept(clazz, method, codeAttribute, oldOffset, this); |
| } |
| |
| // Remap and insert the replacement instruction, or the current |
| // instruction, if it shouldn't be deleted. |
| Instruction replacementInstruction = replacements[oldOffset]; |
| if (replacementInstruction != null) |
| { |
| if (DEBUG) |
| { |
| System.out.println(" Replaced "+replacementInstruction.toString(newOffset)); |
| } |
| // Remap the instruction. |
| replacementInstruction.accept(clazz, method, codeAttribute, oldOffset, this); |
| } |
| else if (!deleted[oldOffset]) |
| { |
| if (DEBUG) |
| { |
| System.out.println(" Copied "+instruction.toString(newOffset)); |
| } |
| |
| // Remap the instruction. |
| instruction.accept(clazz, method, codeAttribute, oldOffset, this); |
| } |
| |
| // Remap and insert the post-inserted instruction, if any. |
| Instruction postInstruction = postInsertions[oldOffset]; |
| if (postInstruction != null) |
| { |
| if (DEBUG) |
| { |
| System.out.println(" Post-inserted "+postInstruction.toString(newOffset)); |
| } |
| |
| // Remap the instruction. |
| postInstruction.accept(clazz, method, codeAttribute, oldOffset, this); |
| } |
| } |
| |
| |
| // Implementations for InstructionVisitor. |
| |
| public void visitSimpleInstruction(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, SimpleInstruction simpleInstruction) |
| { |
| // Write out the instruction. |
| instructionWriter.visitSimpleInstruction(clazz, |
| method, |
| codeAttribute, |
| newOffset, |
| simpleInstruction); |
| |
| newOffset += simpleInstruction.length(newOffset); |
| } |
| |
| |
| public void visitConstantInstruction(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, ConstantInstruction constantInstruction) |
| { |
| // Write out the instruction. |
| instructionWriter.visitConstantInstruction(clazz, |
| method, |
| codeAttribute, |
| newOffset, |
| constantInstruction); |
| |
| newOffset += constantInstruction.length(newOffset); |
| } |
| |
| |
| public void visitVariableInstruction(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, VariableInstruction variableInstruction) |
| { |
| // Write out the instruction. |
| instructionWriter.visitVariableInstruction(clazz, |
| method, |
| codeAttribute, |
| newOffset, |
| variableInstruction); |
| |
| newOffset += variableInstruction.length(newOffset); |
| } |
| |
| |
| public void visitBranchInstruction(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, BranchInstruction branchInstruction) |
| { |
| // Adjust the branch offset. |
| branchInstruction.branchOffset = remapBranchOffset(offset, |
| branchInstruction.branchOffset); |
| |
| // Write out the instruction. |
| instructionWriter.visitBranchInstruction(clazz, |
| method, |
| codeAttribute, |
| newOffset, |
| branchInstruction); |
| |
| newOffset += branchInstruction.length(newOffset); |
| } |
| |
| |
| public void visitTableSwitchInstruction(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, TableSwitchInstruction tableSwitchInstruction) |
| { |
| // Adjust the default jump offset. |
| tableSwitchInstruction.defaultOffset = remapBranchOffset(offset, |
| tableSwitchInstruction.defaultOffset); |
| |
| // Adjust the jump offsets. |
| remapJumpOffsets(offset, |
| tableSwitchInstruction.jumpOffsets); |
| |
| // Write out the instruction. |
| instructionWriter.visitTableSwitchInstruction(clazz, |
| method, |
| codeAttribute, |
| newOffset, |
| tableSwitchInstruction); |
| |
| newOffset += tableSwitchInstruction.length(newOffset); |
| } |
| |
| |
| public void visitLookUpSwitchInstruction(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, LookUpSwitchInstruction lookUpSwitchInstruction) |
| { |
| // Adjust the default jump offset. |
| lookUpSwitchInstruction.defaultOffset = remapBranchOffset(offset, |
| lookUpSwitchInstruction.defaultOffset); |
| |
| // Adjust the jump offsets. |
| remapJumpOffsets(offset, |
| lookUpSwitchInstruction.jumpOffsets); |
| |
| // Write out the instruction. |
| instructionWriter.visitLookUpSwitchInstruction(clazz, |
| method, |
| codeAttribute, |
| newOffset, |
| lookUpSwitchInstruction); |
| |
| newOffset += lookUpSwitchInstruction.length(newOffset); |
| } |
| |
| |
| // Implementations for ExceptionInfoVisitor. |
| |
| public void visitExceptionInfo(Clazz clazz, Method method, CodeAttribute codeAttribute, ExceptionInfo exceptionInfo) |
| { |
| // Remap the code offsets. Note that the instruction offset map also has |
| // an entry for the first offset after the code, for u2endPC. |
| exceptionInfo.u2startPC = remapInstructionOffset(exceptionInfo.u2startPC); |
| exceptionInfo.u2endPC = remapInstructionOffset(exceptionInfo.u2endPC); |
| exceptionInfo.u2handlerPC = remapInstructionOffset(exceptionInfo.u2handlerPC); |
| } |
| |
| |
| // Implementations for StackMapFrameVisitor. |
| |
| public void visitAnyStackMapFrame(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, StackMapFrame stackMapFrame) |
| { |
| // Remap the stack map frame offset. |
| int stackMapFrameOffset = remapInstructionOffset(offset); |
| |
| int offsetDelta = stackMapFrameOffset; |
| |
| // Compute the offset delta if the frame is part of a stack map frame |
| // table (for JDK 6.0) instead of a stack map (for Java Micro Edition). |
| if (expectedStackMapFrameOffset >= 0) |
| { |
| offsetDelta -= expectedStackMapFrameOffset; |
| |
| expectedStackMapFrameOffset = stackMapFrameOffset + 1; |
| } |
| |
| stackMapFrame.u2offsetDelta = offsetDelta; |
| } |
| |
| |
| public void visitSameOneFrame(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, SameOneFrame sameOneFrame) |
| { |
| // Remap the stack map frame offset. |
| visitAnyStackMapFrame(clazz, method, codeAttribute, offset, sameOneFrame); |
| |
| // Remap the verification type offset. |
| sameOneFrame.stackItemAccept(clazz, method, codeAttribute, offset, this); |
| } |
| |
| |
| public void visitMoreZeroFrame(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, MoreZeroFrame moreZeroFrame) |
| { |
| // Remap the stack map frame offset. |
| visitAnyStackMapFrame(clazz, method, codeAttribute, offset, moreZeroFrame); |
| |
| // Remap the verification type offsets. |
| moreZeroFrame.additionalVariablesAccept(clazz, method, codeAttribute, offset, this); |
| } |
| |
| |
| public void visitFullFrame(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, FullFrame fullFrame) |
| { |
| // Remap the stack map frame offset. |
| visitAnyStackMapFrame(clazz, method, codeAttribute, offset, fullFrame); |
| |
| // Remap the verification type offsets. |
| fullFrame.variablesAccept(clazz, method, codeAttribute, offset, this); |
| fullFrame.stackAccept(clazz, method, codeAttribute, offset, this); |
| } |
| |
| |
| // Implementations for VerificationTypeVisitor. |
| |
| public void visitAnyVerificationType(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, VerificationType verificationType) {} |
| |
| |
| public void visitUninitializedType(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, UninitializedType uninitializedType) |
| { |
| // Remap the offset of the 'new' instruction. |
| uninitializedType.u2newInstructionOffset = remapInstructionOffset(uninitializedType.u2newInstructionOffset); |
| } |
| |
| |
| // Implementations for LineNumberInfoVisitor. |
| |
| public void visitLineNumberInfo(Clazz clazz, Method method, CodeAttribute codeAttribute, LineNumberInfo lineNumberInfo) |
| { |
| // Remap the code offset. |
| lineNumberInfo.u2startPC = remapInstructionOffset(lineNumberInfo.u2startPC); |
| } |
| |
| |
| // Implementations for LocalVariableInfoVisitor. |
| |
| public void visitLocalVariableInfo(Clazz clazz, Method method, CodeAttribute codeAttribute, LocalVariableInfo localVariableInfo) |
| { |
| // Remap the code offset and length. |
| // TODO: The local variable frame might not be strictly preserved. |
| localVariableInfo.u2length = remapBranchOffset(localVariableInfo.u2startPC, |
| localVariableInfo.u2length); |
| localVariableInfo.u2startPC = remapInstructionOffset(localVariableInfo.u2startPC); |
| } |
| |
| |
| // Implementations for LocalVariableTypeInfoVisitor. |
| |
| public void visitLocalVariableTypeInfo(Clazz clazz, Method method, CodeAttribute codeAttribute, LocalVariableTypeInfo localVariableTypeInfo) |
| { |
| // Remap the code offset and length. |
| // TODO: The local variable frame might not be strictly preserved. |
| localVariableTypeInfo.u2length = remapBranchOffset(localVariableTypeInfo.u2startPC, |
| localVariableTypeInfo.u2length); |
| localVariableTypeInfo.u2startPC = remapInstructionOffset(localVariableTypeInfo.u2startPC); |
| } |
| |
| |
| // Small utility methods. |
| |
| /** |
| * Adjusts the given jump offsets for the instruction at the given offset. |
| */ |
| private void remapJumpOffsets(int offset, int[] jumpOffsets) |
| { |
| for (int index = 0; index < jumpOffsets.length; index++) |
| { |
| jumpOffsets[index] = remapBranchOffset(offset, jumpOffsets[index]); |
| } |
| } |
| |
| |
| /** |
| * Computes the new branch offset for the instruction at the given offset |
| * with the given branch offset. |
| */ |
| private int remapBranchOffset(int offset, int branchOffset) |
| { |
| return remapInstructionOffset(offset + branchOffset) - newOffset; |
| } |
| |
| |
| /** |
| * Computes the new instruction offset for the instruction at the given offset. |
| */ |
| private int remapInstructionOffset(int offset) |
| { |
| if (offset < 0 || |
| offset > codeLength) |
| { |
| throw new IllegalArgumentException("Invalid instruction offset ["+offset+"] in code with length ["+codeLength+"]"); |
| } |
| |
| return instructionOffsetMap[offset]; |
| } |
| |
| |
| /** |
| * Returns the given list of exceptions, without the ones that have empty |
| * code blocks. |
| */ |
| private int removeEmptyExceptions(ExceptionInfo[] exceptionInfos, |
| int exceptionInfoCount) |
| { |
| // Overwrite all empty exceptions. |
| int newIndex = 0; |
| for (int index = 0; index < exceptionInfoCount; index++) |
| { |
| ExceptionInfo exceptionInfo = exceptionInfos[index]; |
| if (exceptionInfo.u2startPC < exceptionInfo.u2endPC) |
| { |
| exceptionInfos[newIndex++] = exceptionInfo; |
| } |
| } |
| |
| return newIndex; |
| } |
| |
| |
| /** |
| * Returns the given list of line numbers, without the ones that have empty |
| * code blocks or that exceed the code size. |
| */ |
| private int removeEmptyLineNumbers(LineNumberInfo[] lineNumberInfos, |
| int lineNumberInfoCount, |
| int codeLength) |
| { |
| // Overwrite all empty line number entries. |
| int newIndex = 0; |
| for (int index = 0; index < lineNumberInfoCount; index++) |
| { |
| LineNumberInfo lineNumberInfo = lineNumberInfos[index]; |
| int startPC = lineNumberInfo.u2startPC; |
| if (startPC < codeLength && |
| (index == 0 || startPC > lineNumberInfos[index-1].u2startPC)) |
| { |
| lineNumberInfos[newIndex++] = lineNumberInfo; |
| } |
| } |
| |
| return newIndex; |
| } |
| |
| |
| /** |
| * Returns the given list of local variables, without the ones that have empty |
| * code blocks or that exceed the actual number of local variables. |
| */ |
| private int removeEmptyLocalVariables(LocalVariableInfo[] localVariableInfos, |
| int localVariableInfoCount, |
| int maxLocals) |
| { |
| // Overwrite all empty local variable entries. |
| int newIndex = 0; |
| for (int index = 0; index < localVariableInfoCount; index++) |
| { |
| LocalVariableInfo localVariableInfo = localVariableInfos[index]; |
| if (localVariableInfo.u2length > 0 && |
| localVariableInfo.u2index < maxLocals) |
| { |
| localVariableInfos[newIndex++] = localVariableInfo; |
| } |
| } |
| |
| return newIndex; |
| } |
| |
| |
| /** |
| * Returns the given list of local variable types, without the ones that |
| * have empty code blocks or that exceed the actual number of local variables. |
| */ |
| private int removeEmptyLocalVariableTypes(LocalVariableTypeInfo[] localVariableTypeInfos, |
| int localVariableTypeInfoCount, |
| int maxLocals) |
| { |
| // Overwrite all empty local variable type entries. |
| int newIndex = 0; |
| for (int index = 0; index < localVariableTypeInfoCount; index++) |
| { |
| LocalVariableTypeInfo localVariableTypeInfo = localVariableTypeInfos[index]; |
| if (localVariableTypeInfo.u2length > 0 && |
| localVariableTypeInfo.u2index < maxLocals) |
| { |
| localVariableTypeInfos[newIndex++] = localVariableTypeInfo; |
| } |
| } |
| |
| return newIndex; |
| } |
| |
| |
| private class CompositeInstruction |
| extends Instruction |
| { |
| private Instruction[] instructions; |
| |
| |
| private CompositeInstruction(Instruction[] instructions) |
| { |
| this.instructions = instructions; |
| } |
| |
| |
| // Implementations for Instruction. |
| |
| public Instruction shrink() |
| { |
| for (int index = 0; index < instructions.length; index++) |
| { |
| instructions[index] = instructions[index].shrink(); |
| } |
| |
| return this; |
| } |
| |
| |
| public void write(byte[] code, int offset) |
| { |
| for (int index = 0; index < instructions.length; index++) |
| { |
| Instruction instruction = instructions[index]; |
| |
| instruction.write(code, offset); |
| |
| offset += instruction.length(offset); |
| } |
| } |
| |
| |
| protected void readInfo(byte[] code, int offset) |
| { |
| throw new UnsupportedOperationException("Can't read composite instruction"); |
| } |
| |
| |
| protected void writeInfo(byte[] code, int offset) |
| { |
| throw new UnsupportedOperationException("Can't write composite instruction"); |
| } |
| |
| |
| public int length(int offset) |
| { |
| int newOffset = offset; |
| |
| for (int index = 0; index < instructions.length; index++) |
| { |
| newOffset += instructions[index].length(newOffset); |
| } |
| |
| return newOffset - offset; |
| } |
| |
| |
| public void accept(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, InstructionVisitor instructionVisitor) |
| { |
| if (instructionVisitor != CodeAttributeEditor.this) |
| { |
| throw new UnsupportedOperationException("Unexpected visitor ["+instructionVisitor+"]"); |
| } |
| |
| for (int index = 0; index < instructions.length; index++) |
| { |
| Instruction instruction = instructions[index]; |
| |
| instruction.accept(clazz, method, codeAttribute, offset, CodeAttributeEditor.this); |
| |
| offset += instruction.length(offset); |
| } |
| } |
| |
| |
| // Implementations for Object. |
| |
| public String toString() |
| { |
| StringBuffer stringBuffer = new StringBuffer(); |
| |
| for (int index = 0; index < instructions.length; index++) |
| { |
| stringBuffer.append(instructions[index].toString()).append("; "); |
| } |
| |
| return stringBuffer.toString(); |
| } |
| } |
| } |
