/***
* ASM: a very small and fast Java bytecode manipulation framework
* Copyright (c) 2000-2007 INRIA, France Telecom
* 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. Neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS 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 COPYRIGHT OWNER OR 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.
*/
package br.com.caelum.vraptor.asm.util;
import java.io.FileInputStream;
import java.io.PrintWriter;
import br.com.caelum.vraptor.asm.AnnotationVisitor;
import br.com.caelum.vraptor.asm.ClassReader;
import br.com.caelum.vraptor.asm.ClassVisitor;
import br.com.caelum.vraptor.asm.FieldVisitor;
import br.com.caelum.vraptor.asm.MethodVisitor;
import br.com.caelum.vraptor.asm.Opcodes;
/**
* A {@link ClassVisitor} that prints the ASM code that generates the classes it
* visits. This class visitor can be used to quickly write ASM code to generate
* some given bytecode:
* <ul>
* <li>write the Java source code equivalent to the bytecode you want to
* generate;</li>
* <li>compile it with <tt>javac</tt>;</li>
* <li>make a {@link ASMifierClassVisitor} visit this compiled class (see the
* {@link #main main} method);</li>
* <li>edit the generated source code, if necessary.</li>
* </ul>
* The source code printed when visiting the <tt>Hello</tt> class is the
* following:
* <p>
* <blockquote>
*
* <pre>
* import br.com.caelum.vraptor.asm.*;
*
* public class HelloDump implements Opcodes {
*
* public static byte[] dump() throws Exception {
*
* ClassWriter cw = new ClassWriter(0);
* FieldVisitor fv;
* MethodVisitor mv;
* AnnotationVisitor av0;
*
* cw.visit(49, ACC_PUBLIC + ACC_SUPER, "Hello", null, "java/lang/Object", null);
*
* cw.visitSource("Hello.java", null);
*
* {
* mv = cw.visitMethod(ACC_PUBLIC, "<init>", "()V", null, null);
* mv.visitVarInsn(ALOAD, 0);
* mv.visitMethodInsn(INVOKESPECIAL, "java/lang/Object", "<init>", "()V");
* mv.visitInsn(RETURN);
* mv.visitMaxs(1, 1);
* mv.visitEnd();
* }
* {
* mv = cw.visitMethod(ACC_PUBLIC + ACC_STATIC, "main", "([Ljava/lang/String;)V", null, null);
* mv.visitFieldInsn(GETSTATIC, "java/lang/System", "out", "Ljava/io/PrintStream;");
* mv.visitLdcInsn("hello");
* mv.visitMethodInsn(INVOKEVIRTUAL, "java/io/PrintStream", "println", "(Ljava/lang/String;)V");
* mv.visitInsn(RETURN);
* mv.visitMaxs(2, 1);
* mv.visitEnd();
* }
* cw.visitEnd();
*
* return cw.toByteArray();
* }
* }
*
* </pre>
*
* </blockquote> where <tt>Hello</tt> is defined by:
* <p>
* <blockquote>
*
* <pre>
* public class Hello {
*
* public static void main(String[] args) {
* System.out.println("hello");
* }
* }
* </pre>
*
* </blockquote>
*
* @author Eric Bruneton
* @author Eugene Kuleshov
*/
@SuppressWarnings("unchecked")
public class ASMifierClassVisitor extends ASMifierAbstractVisitor implements ClassVisitor {
/**
* Pseudo access flag used to distinguish class access flags.
*/
private static final int ACCESS_CLASS = 262144;
/**
* Pseudo access flag used to distinguish field access flags.
*/
private static final int ACCESS_FIELD = 524288;
/**
* Pseudo access flag used to distinguish inner class flags.
*/
private static final int ACCESS_INNER = 1048576;
/**
* The print writer to be used to print the class.
*/
protected final PrintWriter pw;
/**
* Prints the ASM source code to generate the given class to the standard
* output.
* <p>
* Usage: ASMifierClassVisitor [-debug] <fully qualified class name or
* class file name>
*
* @param args
* the command line arguments.
*
* @throws Exception
* if the class cannot be found, or if an IO exception occurs.
*/
public static void main(final String[] args) throws Exception {
int i = 0;
int flags = ClassReader.SKIP_DEBUG;
boolean ok = true;
if ((args.length < 1) || (args.length > 2)) {
ok = false;
}
if (ok && "-debug".equals(args[0])) {
i = 1;
flags = 0;
if (args.length != 2) {
ok = false;
}
}
if (!ok) {
System.err.println("Prints the ASM code to generate the given class.");
System.err.println("Usage: ASMifierClassVisitor [-debug] "
+ "<fully qualified class name or class file name>");
return;
}
ClassReader cr;
if (args[i].endsWith(".class") || (args[i].indexOf('\\') > -1) || (args[i].indexOf('/') > -1)) {
cr = new ClassReader(new FileInputStream(args[i]));
} else {
cr = new ClassReader(args[i]);
}
cr.accept(new ASMifierClassVisitor(new PrintWriter(System.out)), getDefaultAttributes(), flags);
}
/**
* Constructs a new {@link ASMifierClassVisitor} object.
*
* @param pw
* the print writer to be used to print the class.
*/
public ASMifierClassVisitor(final PrintWriter pw) {
super("cw");
this.pw = pw;
}
// ------------------------------------------------------------------------
// Implementation of the ClassVisitor interface
// ------------------------------------------------------------------------
public void visit(final int version, final int access, final String name, final String signature,
final String superName, final String[] interfaces) {
String simpleName;
int n = name.lastIndexOf('/');
if (n == -1) {
simpleName = name;
} else {
text.add("package asm." + name.substring(0, n).replace('/', '.') + ";\n");
simpleName = name.substring(n + 1);
}
text.add("import java.util.*;\n");
text.add("import br.com.caelum.vraptor.asm.*;\n");
text.add("import br.com.caelum.vraptor.asm.attrs.*;\n");
text.add("public class " + simpleName + "Dump implements Opcodes {\n\n");
text.add("public static byte[] dump () throws Exception {\n\n");
text.add("ClassWriter cw = new ClassWriter(0);\n");
text.add("FieldVisitor fv;\n");
text.add("MethodVisitor mv;\n");
text.add("AnnotationVisitor av0;\n\n");
buf.setLength(0);
buf.append("cw.visit(");
switch (version) {
case Opcodes.V1_1:
buf.append("V1_1");
break;
case Opcodes.V1_2:
buf.append("V1_2");
break;
case Opcodes.V1_3:
buf.append("V1_3");
break;
case Opcodes.V1_4:
buf.append("V1_4");
break;
case Opcodes.V1_5:
buf.append("V1_5");
break;
case Opcodes.V1_6:
buf.append("V1_6");
break;
default:
buf.append(version);
break;
}
buf.append(", ");
appendAccess(access | ACCESS_CLASS);
buf.append(", ");
appendConstant(name);
buf.append(", ");
appendConstant(signature);
buf.append(", ");
appendConstant(superName);
buf.append(", ");
if ((interfaces != null) && (interfaces.length > 0)) {
buf.append("new String[] {");
for (int i = 0; i < interfaces.length; ++i) {
buf.append(i == 0 ? " " : ", ");
appendConstant(interfaces[i]);
}
buf.append(" }");
} else {
buf.append("null");
}
buf.append(");\n\n");
text.add(buf.toString());
}
public void visitSource(final String file, final String debug) {
buf.setLength(0);
buf.append("cw.visitSource(");
appendConstant(file);
buf.append(", ");
appendConstant(debug);
buf.append(");\n\n");
text.add(buf.toString());
}
public void visitOuterClass(final String owner, final String name, final String desc) {
buf.setLength(0);
buf.append("cw.visitOuterClass(");
appendConstant(owner);
buf.append(", ");
appendConstant(name);
buf.append(", ");
appendConstant(desc);
buf.append(");\n\n");
text.add(buf.toString());
}
public void visitInnerClass(final String name, final String outerName, final String innerName, final int access) {
buf.setLength(0);
buf.append("cw.visitInnerClass(");
appendConstant(name);
buf.append(", ");
appendConstant(outerName);
buf.append(", ");
appendConstant(innerName);
buf.append(", ");
appendAccess(access | ACCESS_INNER);
buf.append(");\n\n");
text.add(buf.toString());
}
public FieldVisitor visitField(final int access, final String name, final String desc, final String signature,
final Object value) {
buf.setLength(0);
buf.append("{\n");
buf.append("fv = cw.visitField(");
appendAccess(access | ACCESS_FIELD);
buf.append(", ");
appendConstant(name);
buf.append(", ");
appendConstant(desc);
buf.append(", ");
appendConstant(signature);
buf.append(", ");
appendConstant(value);
buf.append(");\n");
text.add(buf.toString());
ASMifierFieldVisitor aav = new ASMifierFieldVisitor();
text.add(aav.getText());
text.add("}\n");
return aav;
}
public MethodVisitor visitMethod(final int access, final String name, final String desc, final String signature,
final String[] exceptions) {
buf.setLength(0);
buf.append("{\n");
buf.append("mv = cw.visitMethod(");
appendAccess(access);
buf.append(", ");
appendConstant(name);
buf.append(", ");
appendConstant(desc);
buf.append(", ");
appendConstant(signature);
buf.append(", ");
if ((exceptions != null) && (exceptions.length > 0)) {
buf.append("new String[] {");
for (int i = 0; i < exceptions.length; ++i) {
buf.append(i == 0 ? " " : ", ");
appendConstant(exceptions[i]);
}
buf.append(" }");
} else {
buf.append("null");
}
buf.append(");\n");
text.add(buf.toString());
ASMifierMethodVisitor acv = createASMifierMethodVisitor();
text.add(acv.getText());
text.add("}\n");
return acv;
}
protected ASMifierMethodVisitor createASMifierMethodVisitor() {
return new ASMifierMethodVisitor();
}
@Override
public AnnotationVisitor visitAnnotation(final String desc, final boolean visible) {
buf.setLength(0);
buf.append("{\n");
buf.append("av0 = cw.visitAnnotation(");
appendConstant(desc);
buf.append(", ");
buf.append(visible);
buf.append(");\n");
text.add(buf.toString());
ASMifierAnnotationVisitor av = new ASMifierAnnotationVisitor(0);
text.add(av.getText());
text.add("}\n");
return av;
}
@Override
public void visitEnd() {
text.add("cw.visitEnd();\n\n");
text.add("return cw.toByteArray();\n");
text.add("}\n");
text.add("}\n");
printList(pw, text);
pw.flush();
}
// ------------------------------------------------------------------------
// Utility methods
// ------------------------------------------------------------------------
/**
* Appends a string representation of the given access modifiers to
* {@link #buf buf}.
*
* @param access
* some access modifiers.
*/
void appendAccess(final int access) {
boolean first = true;
if ((access & Opcodes.ACC_PUBLIC) != 0) {
buf.append("ACC_PUBLIC");
first = false;
}
if ((access & Opcodes.ACC_PRIVATE) != 0) {
buf.append("ACC_PRIVATE");
first = false;
}
if ((access & Opcodes.ACC_PROTECTED) != 0) {
buf.append("ACC_PROTECTED");
first = false;
}
if ((access & Opcodes.ACC_FINAL) != 0) {
if (!first) {
buf.append(" + ");
}
buf.append("ACC_FINAL");
first = false;
}
if ((access & Opcodes.ACC_STATIC) != 0) {
if (!first) {
buf.append(" + ");
}
buf.append("ACC_STATIC");
first = false;
}
if ((access & Opcodes.ACC_SYNCHRONIZED) != 0) {
if (!first) {
buf.append(" + ");
}
if ((access & ACCESS_CLASS) == 0) {
buf.append("ACC_SYNCHRONIZED");
} else {
buf.append("ACC_SUPER");
}
first = false;
}
if (((access & Opcodes.ACC_VOLATILE) != 0) && ((access & ACCESS_FIELD) != 0)) {
if (!first) {
buf.append(" + ");
}
buf.append("ACC_VOLATILE");
first = false;
}
if (((access & Opcodes.ACC_BRIDGE) != 0) && ((access & ACCESS_CLASS) == 0) && ((access & ACCESS_FIELD) == 0)) {
if (!first) {
buf.append(" + ");
}
buf.append("ACC_BRIDGE");
first = false;
}
if (((access & Opcodes.ACC_VARARGS) != 0) && ((access & ACCESS_CLASS) == 0) && ((access & ACCESS_FIELD) == 0)) {
if (!first) {
buf.append(" + ");
}
buf.append("ACC_VARARGS");
first = false;
}
if (((access & Opcodes.ACC_TRANSIENT) != 0) && ((access & ACCESS_FIELD) != 0)) {
if (!first) {
buf.append(" + ");
}
buf.append("ACC_TRANSIENT");
first = false;
}
if (((access & Opcodes.ACC_NATIVE) != 0) && ((access & ACCESS_CLASS) == 0) && ((access & ACCESS_FIELD) == 0)) {
if (!first) {
buf.append(" + ");
}
buf.append("ACC_NATIVE");
first = false;
}
if (((access & Opcodes.ACC_ENUM) != 0)
&& (((access & ACCESS_CLASS) != 0) || ((access & ACCESS_FIELD) != 0) || ((access & ACCESS_INNER) != 0))) {
if (!first) {
buf.append(" + ");
}
buf.append("ACC_ENUM");
first = false;
}
if (((access & Opcodes.ACC_ANNOTATION) != 0) && ((access & ACCESS_CLASS) != 0)) {
if (!first) {
buf.append(" + ");
}
buf.append("ACC_ANNOTATION");
first = false;
}
if ((access & Opcodes.ACC_ABSTRACT) != 0) {
if (!first) {
buf.append(" + ");
}
buf.append("ACC_ABSTRACT");
first = false;
}
if ((access & Opcodes.ACC_INTERFACE) != 0) {
if (!first) {
buf.append(" + ");
}
buf.append("ACC_INTERFACE");
first = false;
}
if ((access & Opcodes.ACC_STRICT) != 0) {
if (!first) {
buf.append(" + ");
}
buf.append("ACC_STRICT");
first = false;
}
if ((access & Opcodes.ACC_SYNTHETIC) != 0) {
if (!first) {
buf.append(" + ");
}
buf.append("ACC_SYNTHETIC");
first = false;
}
if ((access & Opcodes.ACC_DEPRECATED) != 0) {
if (!first) {
buf.append(" + ");
}
buf.append("ACC_DEPRECATED");
first = false;
}
if (first) {
buf.append('0');
}
}
}