/***
* ASM: a very small and fast Java bytecode manipulation framework
* Copyright (c) 2000-2011 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 scala.tools.asm.util;
import java.io.PrintWriter;
import scala.tools.asm.AnnotationVisitor;
import scala.tools.asm.Attribute;
import scala.tools.asm.ClassVisitor;
import scala.tools.asm.FieldVisitor;
import scala.tools.asm.MethodVisitor;
import scala.tools.asm.Opcodes;
import scala.tools.asm.TypePath;
/**
* A {@link ClassVisitor} that prints the classes it visits with a
* {@link Printer}. This class visitor can be used in the middle of a class
* visitor chain to trace the class that is visited at a given point in this
* chain. This may be useful for debugging purposes.
* <p>
* The trace printed when visiting the <tt>Hello</tt> class is the following:
* <p>
* <blockquote>
*
* <pre>
* // class version 49.0 (49) // access flags 0x21 public class Hello {
*
* // compiled from: Hello.java
*
* // access flags 0x1 public <init> ()V ALOAD 0 INVOKESPECIAL
* java/lang/Object <init> ()V RETURN MAXSTACK = 1 MAXLOCALS = 1
*
* // access flags 0x9 public static main ([Ljava/lang/String;)V GETSTATIC
* java/lang/System out Ljava/io/PrintStream; LDC "hello"
* INVOKEVIRTUAL java/io/PrintStream println (Ljava/lang/String;)V RETURN
* MAXSTACK = 2 MAXLOCALS = 1 }
* </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
*/
public final class TraceClassVisitor extends ClassVisitor {
/**
* The print writer to be used to print the class. May be null.
*/
private final PrintWriter pw;
/**
* The object that actually converts visit events into text.
*/
public final Printer p;
/**
* Constructs a new {@link TraceClassVisitor}.
*
* @param pw
* the print writer to be used to print the class.
*/
public TraceClassVisitor(final PrintWriter pw) {
this(null, pw);
}
/**
* Constructs a new {@link TraceClassVisitor}.
*
* @param cv
* the {@link ClassVisitor} to which this visitor delegates
* calls. May be <tt>null</tt>.
* @param pw
* the print writer to be used to print the class.
*/
public TraceClassVisitor(final ClassVisitor cv, final PrintWriter pw) {
this(cv, new Textifier(), pw);
}
/**
* Constructs a new {@link TraceClassVisitor}.
*
* @param cv
* the {@link ClassVisitor} to which this visitor delegates
* calls. May be <tt>null</tt>.
* @param p
* the object that actually converts visit events into text.
* @param pw
* the print writer to be used to print the class. May be null if
* you simply want to use the result via
* {@link Printer#getText()}, instead of printing it.
*/
public TraceClassVisitor(final ClassVisitor cv, final Printer p,
final PrintWriter pw) {
super(Opcodes.ASM5, cv);
this.pw = pw;
this.p = p;
}
@Override
public void visit(final int version, final int access, final String name,
final String signature, final String superName,
final String[] interfaces) {
p.visit(version, access, name, signature, superName, interfaces);
super.visit(version, access, name, signature, superName, interfaces);
}
@Override
public void visitSource(final String file, final String debug) {
p.visitSource(file, debug);
super.visitSource(file, debug);
}
@Override
public void visitOuterClass(final String owner, final String name,
final String desc) {
p.visitOuterClass(owner, name, desc);
super.visitOuterClass(owner, name, desc);
}
@Override
public AnnotationVisitor visitAnnotation(final String desc,
final boolean visible) {
Printer p = this.p.visitClassAnnotation(desc, visible);
AnnotationVisitor av = cv == null ? null : cv.visitAnnotation(desc,
visible);
return new TraceAnnotationVisitor(av, p);
}
@Override
public AnnotationVisitor visitTypeAnnotation(int typeRef,
TypePath typePath, String desc, boolean visible) {
Printer p = this.p.visitClassTypeAnnotation(typeRef, typePath, desc,
visible);
AnnotationVisitor av = cv == null ? null : cv.visitTypeAnnotation(
typeRef, typePath, desc, visible);
return new TraceAnnotationVisitor(av, p);
}
@Override
public void visitAttribute(final Attribute attr) {
p.visitClassAttribute(attr);
super.visitAttribute(attr);
}
@Override
public void visitInnerClass(final String name, final String outerName,
final String innerName, final int access) {
p.visitInnerClass(name, outerName, innerName, access);
super.visitInnerClass(name, outerName, innerName, access);
}
@Override
public FieldVisitor visitField(final int access, final String name,
final String desc, final String signature, final Object value) {
Printer p = this.p.visitField(access, name, desc, signature, value);
FieldVisitor fv = cv == null ? null : cv.visitField(access, name, desc,
signature, value);
return new TraceFieldVisitor(fv, p);
}
@Override
public MethodVisitor visitMethod(final int access, final String name,
final String desc, final String signature, final String[] exceptions) {
Printer p = this.p.visitMethod(access, name, desc, signature,
exceptions);
MethodVisitor mv = cv == null ? null : cv.visitMethod(access, name,
desc, signature, exceptions);
return new TraceMethodVisitor(mv, p);
}
@Override
public void visitEnd() {
p.visitClassEnd();
if (pw != null) {
p.print(pw);
pw.flush();
}
super.visitEnd();
}
}