diff options
Diffstat (limited to 'src/proguard/optimize/peephole/GotoGotoReplacer.java')
-rw-r--r-- | src/proguard/optimize/peephole/GotoGotoReplacer.java | 115 |
1 files changed, 0 insertions, 115 deletions
diff --git a/src/proguard/optimize/peephole/GotoGotoReplacer.java b/src/proguard/optimize/peephole/GotoGotoReplacer.java deleted file mode 100644 index bf7292b..0000000 --- a/src/proguard/optimize/peephole/GotoGotoReplacer.java +++ /dev/null @@ -1,115 +0,0 @@ -/* - * ProGuard -- shrinking, optimization, obfuscation, and preverification - * of Java bytecode. - * - * Copyright (c) 2002-2014 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.peephole; - -import proguard.classfile.*; -import proguard.classfile.attribute.CodeAttribute; -import proguard.classfile.editor.CodeAttributeEditor; -import proguard.classfile.instruction.*; -import proguard.classfile.instruction.visitor.InstructionVisitor; -import proguard.classfile.util.SimplifiedVisitor; - -/** - * This InstructionVisitor simplifies unconditional branches to other - * unconditional branches. - * - * @author Eric Lafortune - */ -public class GotoGotoReplacer -extends SimplifiedVisitor -implements InstructionVisitor -{ - private final CodeAttributeEditor codeAttributeEditor; - private final InstructionVisitor extraInstructionVisitor; - - - /** - * Creates a new GotoGotoReplacer. - * @param codeAttributeEditor a code editor that can be used for - * accumulating changes to the code. - */ - public GotoGotoReplacer(CodeAttributeEditor codeAttributeEditor) - { - this(codeAttributeEditor, null); - } - - - /** - * Creates a new GotoGotoReplacer. - * @param codeAttributeEditor a code editor that can be used for - * accumulating changes to the code. - * @param extraInstructionVisitor an optional extra visitor for all replaced - * goto instructions. - */ - public GotoGotoReplacer(CodeAttributeEditor codeAttributeEditor, - InstructionVisitor extraInstructionVisitor) - { - this.codeAttributeEditor = codeAttributeEditor; - this.extraInstructionVisitor = extraInstructionVisitor; - } - - - // Implementations for InstructionVisitor. - - public void visitAnyInstruction(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, Instruction instruction) {} - - - public void visitBranchInstruction(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, BranchInstruction branchInstruction) - { - // Check if the instruction is an unconditional goto instruction. - byte opcode = branchInstruction.opcode; - if (opcode == InstructionConstants.OP_GOTO || - opcode == InstructionConstants.OP_GOTO_W) - { - // Check if the goto instruction points to another simple goto - // instruction. - int branchOffset = branchInstruction.branchOffset; - int targetOffset = offset + branchOffset; - - if (branchOffset != 0 && - branchOffset != branchInstruction.length(offset) && - !codeAttributeEditor.isModified(offset) && - !codeAttributeEditor.isModified(targetOffset)) - { - Instruction targetInstruction = - InstructionFactory.create(codeAttribute.code, targetOffset); - - if (targetInstruction.opcode == InstructionConstants.OP_GOTO) - { - // Simplify the goto instruction. - int targetBranchOffset = ((BranchInstruction)targetInstruction).branchOffset; - - Instruction newBranchInstruction = - new BranchInstruction(opcode, - (branchOffset + targetBranchOffset)); - codeAttributeEditor.replaceInstruction(offset, - newBranchInstruction); - - // Visit the instruction, if required. - if (extraInstructionVisitor != null) - { - extraInstructionVisitor.visitBranchInstruction(clazz, method, codeAttribute, offset, branchInstruction); - } - } - } - } - } -} |