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- package org.aspectj.apache.bcel.verifier.util;
-
- /* ====================================================================
- * The Apache Software License, Version 1.1
- *
- * Copyright (c) 2002 The Apache Software Foundation. All rights
- * reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in
- * the documentation and/or other materials provided with the
- * distribution.
- *
- * 3. The end-user documentation included with the redistribution,
- * if any, must include the following acknowledgment:
- * "This product includes software developed by the
- * Apache Software Foundation (https://www.apache.org/)."
- * Alternately, this acknowledgment may appear in the software itself,
- * if and wherever such third-party acknowledgments normally appear.
- *
- * 4. The names "Apache" and "Apache Software Foundation" and
- * "Apache BCEL" must not be used to endorse or promote products
- * derived from this software without prior written permission. For
- * written permission, please contact apache@apache.org.
- *
- * 5. Products derived from this software may not be called "Apache",
- * "Apache BCEL", nor may "Apache" appear in their name, without
- * prior written permission of the Apache Software Foundation.
- *
- * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
- * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
- * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
- * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
- * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
- * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
- * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
- * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
- * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- * ====================================================================
- *
- * This software consists of voluntary contributions made by many
- * individuals on behalf of the Apache Software Foundation. For more
- * information on the Apache Software Foundation, please see
- * <https://www.apache.org/>.
- */
- import java.io.OutputStream;
- import java.io.PrintWriter;
-
- import org.aspectj.apache.bcel.Constants;
- import org.aspectj.apache.bcel.Repository;
- import org.aspectj.apache.bcel.classfile.ClassParser;
- import org.aspectj.apache.bcel.classfile.ConstantValue;
- import org.aspectj.apache.bcel.classfile.Field;
- import org.aspectj.apache.bcel.classfile.JavaClass;
- import org.aspectj.apache.bcel.classfile.Method;
- import org.aspectj.apache.bcel.classfile.Utility;
- import org.aspectj.apache.bcel.generic.ArrayType;
- import org.aspectj.apache.bcel.classfile.ConstantPool;
- import org.aspectj.apache.bcel.generic.MethodGen;
- import org.aspectj.apache.bcel.generic.Type;
-
- /**
- * This class takes a given JavaClass object and converts it to a
- * Java program that creates that very class using BCEL. This
- * gives new users of BCEL a useful example showing how things
- * are done with BCEL. It does not cover all features of BCEL,
- * but tries to mimic hand-written code as close as possible.
- *
- * @version $Id: BCELifier.java,v 1.2 2008/05/28 23:53:04 aclement Exp $
- * @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
- */
- public class BCELifier extends org.aspectj.apache.bcel.verifier.EmptyClassVisitor {
- private JavaClass _clazz;
- private PrintWriter _out;
- private ConstantPool _cp;
-
- /** @param clazz Java class to "decompile"
- * @param out where to output Java program
- */
- public BCELifier(JavaClass clazz, OutputStream out) {
- _clazz = clazz;
- _out = new PrintWriter(out);
- _cp = new ConstantPool(_clazz.getConstantPool().getConstantPool());
- }
-
- /** Start Java code generation
- */
- public void start() {
- visitJavaClass(_clazz);
- _out.flush();
- }
-
- public void visitJavaClass(JavaClass clazz) {
- String class_name = clazz.getClassName();
- String super_name = clazz.getSuperclassName();
- String package_name = clazz.getPackageName();
- String inter = BCELifier.printArray(clazz.getInterfaceNames(),
- false, true);
- if(!"".equals(package_name)) {
- class_name = class_name.substring(package_name.length() + 1);
- _out.println("package " + package_name + ";\n");
- }
-
- _out.println("import org.aspectj.apache.bcel.generic.*;");
- _out.println("import org.aspectj.apache.bcel.classfile.*;");
- _out.println("import org.aspectj.apache.bcel.*;");
- _out.println("import java.io.*;\n");
-
- _out.println("public class " + class_name + "Creator implements Constants {");
- _out.println(" private InstructionFactory _factory;");
- _out.println(" private ConstantPoolGen _cp;");
- _out.println(" private ClassGen _cg;\n");
-
- _out.println(" public " + class_name + "Creator() {");
- _out.println(" _cg = new ClassGen(\"" +
- (("".equals(package_name))? class_name :
- package_name + "." + class_name) +
- "\", \"" + super_name + "\", " +
- "\"" + clazz.getSourceFileName() + "\", " +
- printFlags(clazz.getModifiers(), true) + ", " +
- "new String[] { " + inter + " });\n");
-
- _out.println(" _cp = _cg.getConstantPool();");
- _out.println(" _factory = new InstructionFactory(_cg, _cp);");
- _out.println(" }\n");
-
- printCreate();
-
- Field[] fields = clazz.getFields();
-
- if(fields.length > 0) {
- _out.println(" private void createFields() {");
- _out.println(" FieldGen field;");
-
- for(int i=0; i < fields.length; i++) {
- fields[i].accept(this);
- }
-
- _out.println(" }\n");
- }
-
- Method[] methods = clazz.getMethods();
-
- for(int i=0; i < methods.length; i++) {
- _out.println(" private void createMethod_" + i + "() {");
-
- methods[i].accept(this);
- _out.println(" }\n");
- }
-
- printMain();
- _out.println("}");
- }
-
- private void printCreate() {
- _out.println(" public void create(OutputStream out) throws IOException {");
-
- Field[] fields = _clazz.getFields();
- if(fields.length > 0) {
- _out.println(" createFields();");
- }
-
- Method[] methods = _clazz.getMethods();
- for(int i=0; i < methods.length; i++) {
- _out.println(" createMethod_" + i + "();");
- }
-
- _out.println(" _cg.getJavaClass().dump(out);");
-
- _out.println(" }\n");
- }
-
- private void printMain() {
- String class_name = _clazz.getClassName();
-
- _out.println(" public static void main(String[] args) throws Exception {");
- _out.println(" " + class_name + "Creator creator = new " +
- class_name + "Creator();");
- _out.println(" creator.create(new FileOutputStream(\"" + class_name +
- ".class\"));");
- _out.println(" }");
- }
-
- public void visitField(Field field) {
- _out.println("\n field = new FieldGen(" +
- printFlags(field.getModifiers()) +
- ", " + printType(field.getSignature()) + ", \"" +
- field.getName() + "\", _cp);");
-
- ConstantValue cv = field.getConstantValue();
-
- if(cv != null) {
- String value = cv.toString();
- _out.println(" field.setInitValue(" + value + ")");
- }
-
- _out.println(" _cg.addField(field.getField());");
- }
-
- public void visitMethod(Method method) {
- MethodGen mg = new MethodGen(method, _clazz.getClassName(), _cp);
-
- Type result_type = mg.getReturnType();
- Type[] arg_types = mg.getArgumentTypes();
-
- _out.println(" InstructionList il = new InstructionList();");
- _out.println(" MethodGen method = new MethodGen(" +
- printFlags(method.getModifiers()) +
- ", " + printType(result_type) +
- ", " + printArgumentTypes(arg_types) + ", " +
- "new String[] { " +
- BCELifier.printArray(mg.getArgumentNames(), false, true) +
- " }, \"" + method.getName() + "\", \"" +
- _clazz.getClassName() + "\", il, _cp);\n");
-
- BCELFactory factory = new BCELFactory(mg, _out);
- factory.start();
-
- _out.println(" method.setMaxStack();");
- _out.println(" method.setMaxLocals();");
- _out.println(" _cg.addMethod(method.getMethod());");
- _out.println(" il.dispose();");
- }
-
- public static final String printArray(Object[] obj, boolean braces,
- boolean quote) {
- if(obj == null)
- return null;
-
- StringBuffer buf = new StringBuffer();
- if(braces)
- buf.append('{');
-
- for(int i=0; i < obj.length; i++) {
- if(obj[i] != null) {
- buf.append((quote? "\"" : "") + obj[i].toString() + (quote? "\"" : ""));
- } else {
- buf.append("null");
- }
-
- if(i < obj.length - 1) {
- buf.append(", ");
- }
- }
-
- if(braces)
- buf.append('}');
-
- return buf.toString();
- }
-
- static String printFlags(int flags) {
- return printFlags(flags, false);
- }
-
- static String printFlags(int flags, boolean for_class) {
- if(flags == 0)
- return "0";
-
- StringBuffer buf = new StringBuffer();
- for(int i=0, pow=1; i <= Constants.MAX_ACC_FLAG; i++) {
- if((flags & pow) != 0) {
- if((pow == Constants.ACC_SYNCHRONIZED) && for_class)
- buf.append("ACC_SUPER | ");
- else
- buf.append("ACC_" + Constants.ACCESS_NAMES[i].toUpperCase() + " | ");
- }
-
- pow <<= 1;
- }
-
- String str = buf.toString();
- return str.substring(0, str.length() - 3);
- }
-
- static String printArgumentTypes(Type[] arg_types) {
- if(arg_types.length == 0)
- return "Type.NO_ARGS";
-
- StringBuffer args = new StringBuffer();
-
- for(int i=0; i < arg_types.length; i++) {
- args.append(printType(arg_types[i]));
-
- if(i < arg_types.length - 1)
- args.append(", ");
- }
-
- return "new Type[] { " + args.toString() + " }";
- }
-
- static String printType(Type type) {
- return printType(type.getSignature());
- }
-
- static String printType(String signature) {
- Type type = Type.getType(signature);
- byte t = type.getType();
-
- if(t <= Constants.T_VOID) {
- return "Type." + Constants.TYPE_NAMES[t].toUpperCase();
- } else if(type.toString().equals("java.lang.String")) {
- return "Type.STRING";
- } else if(type.toString().equals("java.lang.Object")) {
- return "Type.OBJECT";
- } else if(type.toString().equals("java.lang.StringBuffer")) {
- return "Type.STRINGBUFFER";
- } else if(type instanceof ArrayType) {
- ArrayType at = (ArrayType)type;
-
- return "new ArrayType(" + printType(at.getBasicType()) +
- ", " + at.getDimensions() + ")";
- } else {
- return "new ObjectType(\"" + Utility.signatureToString(signature, false) +
- "\")";
- }
- }
-
- /** Default main method
- */
- public static void main(String[] argv) throws Exception {
- JavaClass java_class;
- String name = argv[0];
-
- if((java_class = Repository.lookupClass(name)) == null)
- java_class = new ClassParser(name).parse(); // May throw IOException
-
- BCELifier bcelifier = new BCELifier(java_class, System.out);
- bcelifier.start();
- }
- }
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