org.objectweb.asm.util

Class TraceClassVisitor

Implemented Interfaces:
ClassVisitor

public class TraceClassVisitor
extends TraceAbstractVisitor
implements ClassVisitor

A ClassVisitor that prints a disassembled view of the classes it visits. This class visitor can be used alone (see the main method) to disassemble a class. It can also be used in the middle of class visitor chain to trace the class that is visited at a given point in this chain. This may be uselful for debugging purposes.

The trace printed when visiting the Hello class is the following:

 // class version 49.0 (49)
 // access flags 33
 public class Hello {

  // compiled from: Hello.java

   // access flags 1
   public <init> ()V
     ALOAD 0
     INVOKESPECIAL java/lang/Object <init> ()V
     RETURN
     MAXSTACK = 1
     MAXLOCALS = 1

   // access flags 9
   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
 }
 
where Hello is defined by:

 public class Hello {

     public static void main(String[] args) {
         System.out.println("hello");
     }
 }
 
Authors:
Eric Bruneton
Eugene Kuleshov

Field Summary

protected ClassVisitor
cv
The ClassVisitor to which this visitor delegates calls.
protected PrintWriter
pw
The print writer to be used to print the class.

Fields inherited from class org.objectweb.asm.util.TraceAbstractVisitor

CLASS_DECLARATION, CLASS_SIGNATURE, FIELD_DESCRIPTOR, FIELD_SIGNATURE, INTERNAL_NAME, METHOD_DESCRIPTOR, METHOD_SIGNATURE, PARAMETERS_DECLARATION, TYPE_DECLARATION, tab

Fields inherited from class org.objectweb.asm.util.AbstractVisitor

OPCODES, TYPES, buf, text

Constructor Summary

TraceClassVisitor(PrintWriter pw)
Constructs a new TraceClassVisitor.
TraceClassVisitor(ClassVisitor cv, PrintWriter pw)
Constructs a new TraceClassVisitor.

Method Summary

protected TraceFieldVisitor
createTraceFieldVisitor()
protected TraceMethodVisitor
createTraceMethodVisitor()
static void
main(String[] args)
Prints a disassembled view of the given class to the standard output.
void
visit(int version, int access, String name, String signature, String superName, String[] interfaces)
AnnotationVisitor
visitAnnotation(String desc, boolean visible)
void
visitAttribute(Attribute attr)
void
visitEnd()
FieldVisitor
visitField(int access, String name, String desc, String signature, Object value)
void
visitInnerClass(String name, String outerName, String innerName, int access)
MethodVisitor
visitMethod(int access, String name, String desc, String signature, String[] exceptions)
void
visitOuterClass(String owner, String name, String desc)
void
visitSource(String file, String debug)

Methods inherited from class org.objectweb.asm.util.TraceAbstractVisitor

appendDescriptor, createTraceAnnotationVisitor, visitAnnotation, visitAttribute, visitEnd

Methods inherited from class org.objectweb.asm.util.AbstractVisitor

appendString, getDefaultAttributes, getText

Field Details

cv

protected final ClassVisitor cv
The ClassVisitor to which this visitor delegates calls. May be null.

pw

protected final PrintWriter pw
The print writer to be used to print the class.

Constructor Details

TraceClassVisitor

public TraceClassVisitor(PrintWriter pw)
Parameters:
pw - the print writer to be used to print the class.

TraceClassVisitor

public TraceClassVisitor(ClassVisitor cv,
                         PrintWriter pw)
Constructs a new TraceClassVisitor.
Parameters:
cv - the ClassVisitor to which this visitor delegates calls. May be null.
pw - the print writer to be used to print the class.

Method Details

createTraceFieldVisitor

protected TraceFieldVisitor createTraceFieldVisitor()

createTraceMethodVisitor

protected TraceMethodVisitor createTraceMethodVisitor()

main

public static void main(String[] args)
            throws Exception
Prints a disassembled view of the given class to the standard output.

Usage: TraceClassVisitor [-debug] <fully qualified class name or class file name >

Parameters:
args - the command line arguments.

visit

public void visit(int version,
                  int access,
                  String name,
                  String signature,
                  String superName,
                  String[] interfaces)
Specified by:
visit in interface ClassVisitor

visitAnnotation

public AnnotationVisitor visitAnnotation(String desc,
                                         boolean visible)
Specified by:
visitAnnotation in interface ClassVisitor
Overrides:
visitAnnotation in interface TraceAbstractVisitor

visitAttribute

public void visitAttribute(Attribute attr)
Specified by:
visitAttribute in interface ClassVisitor
Overrides:
visitAttribute in interface TraceAbstractVisitor

visitEnd

public void visitEnd()
Specified by:
visitEnd in interface ClassVisitor
Overrides:
visitEnd in interface TraceAbstractVisitor

visitField

public FieldVisitor visitField(int access,
                               String name,
                               String desc,
                               String signature,
                               Object value)
Specified by:
visitField in interface ClassVisitor

visitInnerClass

public void visitInnerClass(String name,
                            String outerName,
                            String innerName,
                            int access)
Specified by:
visitInnerClass in interface ClassVisitor

visitMethod

public MethodVisitor visitMethod(int access,
                                 String name,
                                 String desc,
                                 String signature,
                                 String[] exceptions)
Specified by:
visitMethod in interface ClassVisitor

visitOuterClass

public void visitOuterClass(String owner,
                            String name,
                            String desc)
Specified by:
visitOuterClass in interface ClassVisitor

visitSource

public void visitSource(String file,
                        String debug)
Specified by:
visitSource in interface ClassVisitor