summaryrefslogtreecommitdiff
path: root/src/proguard/optimize/peephole/GotoGotoReplacer.java
diff options
context:
space:
mode:
Diffstat (limited to 'src/proguard/optimize/peephole/GotoGotoReplacer.java')
-rw-r--r--src/proguard/optimize/peephole/GotoGotoReplacer.java115
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);
- }
- }
- }
- }
- }
-}