author | joehw |
Wed, 26 Jun 2019 05:49:59 +0000 | |
changeset 55496 | 8e0ae3830fca |
parent 47216 | 71c04702a3d5 |
permissions | -rw-r--r-- |
6 | 1 |
/* |
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* reserved comment block |
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* DO NOT REMOVE OR ALTER! |
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*/ |
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8b3b3b911b8a
8162572: Update License Header for all JAXP sources
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parents:
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/* |
8b3b3b911b8a
8162572: Update License Header for all JAXP sources
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parents:
25868
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* Licensed to the Apache Software Foundation (ASF) under one or more |
8b3b3b911b8a
8162572: Update License Header for all JAXP sources
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parents:
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* contributor license agreements. See the NOTICE file distributed with |
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8162572: Update License Header for all JAXP sources
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parents:
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* this work for additional information regarding copyright ownership. |
8b3b3b911b8a
8162572: Update License Header for all JAXP sources
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* The ASF licenses this file to You under the Apache License, Version 2.0 |
8b3b3b911b8a
8162572: Update License Header for all JAXP sources
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parents:
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* (the "License"); you may not use this file except in compliance with |
8b3b3b911b8a
8162572: Update License Header for all JAXP sources
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parents:
25868
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* the License. You may obtain a copy of the License at |
8b3b3b911b8a
8162572: Update License Header for all JAXP sources
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parents:
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* |
8b3b3b911b8a
8162572: Update License Header for all JAXP sources
joehw
parents:
25868
diff
changeset
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* http://www.apache.org/licenses/LICENSE-2.0 |
8b3b3b911b8a
8162572: Update License Header for all JAXP sources
joehw
parents:
25868
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* |
8b3b3b911b8a
8162572: Update License Header for all JAXP sources
joehw
parents:
25868
diff
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* Unless required by applicable law or agreed to in writing, software |
8b3b3b911b8a
8162572: Update License Header for all JAXP sources
joehw
parents:
25868
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* distributed under the License is distributed on an "AS IS" BASIS, |
8b3b3b911b8a
8162572: Update License Header for all JAXP sources
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parents:
25868
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
8b3b3b911b8a
8162572: Update License Header for all JAXP sources
joehw
parents:
25868
diff
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* See the License for the specific language governing permissions and |
8b3b3b911b8a
8162572: Update License Header for all JAXP sources
joehw
parents:
25868
diff
changeset
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* limitations under the License. |
8b3b3b911b8a
8162572: Update License Header for all JAXP sources
joehw
parents:
25868
diff
changeset
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*/ |
8b3b3b911b8a
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parents:
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package com.sun.org.apache.bcel.internal.util; |
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import java.io.IOException; |
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import java.io.OutputStream; |
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import java.io.PrintWriter; |
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import java.util.Locale; |
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import com.sun.org.apache.bcel.internal.Const; |
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import com.sun.org.apache.bcel.internal.Repository; |
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import com.sun.org.apache.bcel.internal.classfile.ClassParser; |
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import com.sun.org.apache.bcel.internal.classfile.ConstantValue; |
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import com.sun.org.apache.bcel.internal.classfile.Field; |
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import com.sun.org.apache.bcel.internal.classfile.JavaClass; |
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import com.sun.org.apache.bcel.internal.classfile.Method; |
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import com.sun.org.apache.bcel.internal.classfile.Utility; |
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import com.sun.org.apache.bcel.internal.generic.ArrayType; |
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import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen; |
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import com.sun.org.apache.bcel.internal.generic.MethodGen; |
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import com.sun.org.apache.bcel.internal.generic.Type; |
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/** |
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* This class takes a given JavaClass object and converts it to a |
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* Java program that creates that very class using BCEL. This |
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* gives new users of BCEL a useful example showing how things |
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* are done with BCEL. It does not cover all features of BCEL, |
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* but tries to mimic hand-written code as close as possible. |
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* |
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* @version $Id$ |
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*/ |
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public class BCELifier extends com.sun.org.apache.bcel.internal.classfile.EmptyVisitor { |
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/** |
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* Enum corresponding to flag source. |
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*/ |
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public enum FLAGS { |
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UNKNOWN, |
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CLASS, |
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METHOD, |
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} |
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// The base package name for imports; assumes Const is at the top level |
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// N.B we use the class so renames will be detected by the compiler/IDE |
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private static final String BASE_PACKAGE = Const.class.getPackage().getName(); |
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private static final String CONSTANT_PREFIX = Const.class.getSimpleName()+"."; |
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private final JavaClass _clazz; |
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private final PrintWriter _out; |
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private final ConstantPoolGen _cp; |
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/** @param clazz Java class to "decompile" |
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* @param out where to output Java program |
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*/ |
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public BCELifier(final JavaClass clazz, final OutputStream out) { |
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_clazz = clazz; |
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_out = new PrintWriter(out); |
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_cp = new ConstantPoolGen(_clazz.getConstantPool()); |
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} |
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/** Start Java code generation |
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*/ |
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public void start() { |
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visitJavaClass(_clazz); |
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_out.flush(); |
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} |
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@Override |
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public void visitJavaClass( final JavaClass clazz ) { |
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String class_name = clazz.getClassName(); |
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final String super_name = clazz.getSuperclassName(); |
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final String package_name = clazz.getPackageName(); |
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final String inter = Utility.printArray(clazz.getInterfaceNames(), false, true); |
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if (!"".equals(package_name)) { |
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class_name = class_name.substring(package_name.length() + 1); |
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_out.println("package " + package_name + ";"); |
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_out.println(); |
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} |
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_out.println("import " + BASE_PACKAGE + ".generic.*;"); |
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_out.println("import " + BASE_PACKAGE + ".classfile.*;"); |
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_out.println("import " + BASE_PACKAGE + ".*;"); |
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_out.println("import java.io.*;"); |
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_out.println(); |
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_out.println("public class " + class_name + "Creator {"); |
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_out.println(" private InstructionFactory _factory;"); |
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_out.println(" private ConstantPoolGen _cp;"); |
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_out.println(" private ClassGen _cg;"); |
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_out.println(); |
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_out.println(" public " + class_name + "Creator() {"); |
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_out.println(" _cg = new ClassGen(\"" |
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+ (("".equals(package_name)) ? class_name : package_name + "." + class_name) |
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+ "\", \"" + super_name + "\", " + "\"" + clazz.getSourceFileName() + "\", " |
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+ printFlags(clazz.getAccessFlags(), FLAGS.CLASS) + ", " |
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+ "new String[] { " + inter + " });"); |
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_out.println(); |
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_out.println(" _cp = _cg.getConstantPool();"); |
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_out.println(" _factory = new InstructionFactory(_cg, _cp);"); |
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_out.println(" }"); |
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_out.println(); |
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printCreate(); |
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final Field[] fields = clazz.getFields(); |
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if (fields.length > 0) { |
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_out.println(" private void createFields() {"); |
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_out.println(" FieldGen field;"); |
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for (final Field field : fields) { |
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field.accept(this); |
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} |
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_out.println(" }"); |
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_out.println(); |
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} |
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final Method[] methods = clazz.getMethods(); |
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for (int i = 0; i < methods.length; i++) { |
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_out.println(" private void createMethod_" + i + "() {"); |
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methods[i].accept(this); |
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_out.println(" }"); |
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_out.println(); |
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} |
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printMain(); |
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_out.println("}"); |
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} |
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private void printCreate() { |
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_out.println(" public void create(OutputStream out) throws IOException {"); |
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final Field[] fields = _clazz.getFields(); |
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if (fields.length > 0) { |
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_out.println(" createFields();"); |
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} |
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final Method[] methods = _clazz.getMethods(); |
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for (int i = 0; i < methods.length; i++) { |
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_out.println(" createMethod_" + i + "();"); |
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} |
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_out.println(" _cg.getJavaClass().dump(out);"); |
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_out.println(" }"); |
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_out.println(); |
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} |
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private void printMain() { |
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final String class_name = _clazz.getClassName(); |
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_out.println(" public static void main(String[] args) throws Exception {"); |
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_out.println(" " + class_name + "Creator creator = new " + class_name + "Creator();"); |
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_out.println(" creator.create(new FileOutputStream(\"" + class_name + ".class\"));"); |
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_out.println(" }"); |
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} |
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@Override |
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public void visitField( final Field field ) { |
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_out.println(); |
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_out.println(" field = new FieldGen(" + printFlags(field.getAccessFlags()) + ", " |
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+ printType(field.getSignature()) + ", \"" + field.getName() + "\", _cp);"); |
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final ConstantValue cv = field.getConstantValue(); |
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if (cv != null) { |
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final String value = cv.toString(); |
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_out.println(" field.setInitValue(" + value + ")"); |
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} |
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_out.println(" _cg.addField(field.getField());"); |
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} |
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@Override |
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public void visitMethod( final Method method ) { |
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final MethodGen mg = new MethodGen(method, _clazz.getClassName(), _cp); |
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_out.println(" InstructionList il = new InstructionList();"); |
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_out.println(" MethodGen method = new MethodGen(" |
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+ printFlags(method.getAccessFlags(), FLAGS.METHOD) + ", " |
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+ printType(mg.getReturnType()) + ", " |
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+ printArgumentTypes(mg.getArgumentTypes()) + ", " |
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+ "new String[] { " + Utility.printArray(mg.getArgumentNames(), false, true) |
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+ " }, \"" + method.getName() + "\", \"" + _clazz.getClassName() + "\", il, _cp);"); |
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_out.println(); |
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final BCELFactory factory = new BCELFactory(mg, _out); |
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factory.start(); |
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_out.println(" method.setMaxStack();"); |
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_out.println(" method.setMaxLocals();"); |
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_out.println(" _cg.addMethod(method.getMethod());"); |
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_out.println(" il.dispose();"); |
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} |
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static String printFlags( final int flags ) { |
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return printFlags(flags, FLAGS.UNKNOWN); |
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} |
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/** |
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* Return a string with the flag settings |
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* @param flags the flags field to interpret |
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* @param location the item type |
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* @return the formatted string |
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* @since 6.0 made public |
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*/ |
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public static String printFlags( final int flags, final FLAGS location ) { |
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if (flags == 0) { |
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return "0"; |
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} |
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final StringBuilder buf = new StringBuilder(); |
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for (int i = 0, pow = 1; pow <= Const.MAX_ACC_FLAG; i++) { |
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if ((flags & pow) != 0) { |
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if ((pow == Const.ACC_SYNCHRONIZED) && (location == FLAGS.CLASS)) { |
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buf.append(CONSTANT_PREFIX+"ACC_SUPER | "); |
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} else if ((pow == Const.ACC_VOLATILE) && (location == FLAGS.METHOD)) { |
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buf.append(CONSTANT_PREFIX+"ACC_BRIDGE | "); |
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} else if ((pow == Const.ACC_TRANSIENT) && (location == FLAGS.METHOD)) { |
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buf.append(CONSTANT_PREFIX+"ACC_VARARGS | "); |
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} else { |
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if (i < Const.ACCESS_NAMES_LENGTH) { |
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buf.append(CONSTANT_PREFIX+"ACC_") |
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.append(Const.getAccessName(i).toUpperCase(Locale.ENGLISH)) |
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.append( " | "); |
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} else { |
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buf.append(String.format (CONSTANT_PREFIX+"ACC_BIT %x | ", pow)); |
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} |
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} |
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} |
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pow <<= 1; |
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} |
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final String str = buf.toString(); |
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return str.substring(0, str.length() - 3); |
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} |
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static String printArgumentTypes( final Type[] arg_types ) { |
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if (arg_types.length == 0) { |
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return "Type.NO_ARGS"; |
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} |
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final StringBuilder args = new StringBuilder(); |
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for (int i = 0; i < arg_types.length; i++) { |
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args.append(printType(arg_types[i])); |
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if (i < arg_types.length - 1) { |
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args.append(", "); |
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} |
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} |
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return "new Type[] { " + args.toString() + " }"; |
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} |
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static String printType( final Type type ) { |
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return printType(type.getSignature()); |
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} |
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static String printType( final String signature ) { |
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final Type type = Type.getType(signature); |
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final byte t = type.getType(); |
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if (t <= Const.T_VOID) { |
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return "Type." + Const.getTypeName(t).toUpperCase(Locale.ENGLISH); |
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} else if (type.toString().equals("java.lang.String")) { |
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return "Type.STRING"; |
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} else if (type.toString().equals("java.lang.Object")) { |
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return "Type.OBJECT"; |
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} else if (type.toString().equals("java.lang.StringBuffer")) { |
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return "Type.STRINGBUFFER"; |
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} else if (type instanceof ArrayType) { |
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final ArrayType at = (ArrayType) type; |
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return "new ArrayType(" + printType(at.getBasicType()) + ", " + at.getDimensions() |
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+ ")"; |
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} else { |
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return "new ObjectType(\"" + Utility.signatureToString(signature, false) + "\")"; |
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} |
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} |
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/** Default main method |
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*/ |
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public static void main( final String[] argv ) throws Exception { |
46174 | 288 |
if (argv.length != 1) { |
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System.out.println("Usage: BCELifier classname"); |
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System.out.println("\tThe class must exist on the classpath"); |
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return; |
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} |
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final JavaClass java_class = getJavaClass(argv[0]); |
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final BCELifier bcelifier = new BCELifier(java_class, System.out); |
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bcelifier.start(); |
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} |
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// Needs to be accessible from unit test code |
300 |
static JavaClass getJavaClass(final String name) throws ClassNotFoundException, IOException { |
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JavaClass java_class; |
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if ((java_class = Repository.lookupClass(name)) == null) { |
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java_class = new ClassParser(name).parse(); // May throw IOException |
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} |
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return java_class; |
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} |
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} |