org.iqual.chaplin.trait
Class TraitTransformer

java.lang.Object
  org.objectweb.asm.ClassAdapter
      org.iqual.chaplin.trait.TraitTransformer

All Implemented Interfaces:

org.objectweb.asm.ClassVisitor

public class TraitTransformer
extends org.objectweb.asm.ClassAdapter

This class performs a pre-transformation of classes before they are transformed by FieldRedirector. It uses its own semantics to produce classes adorned by the semantics of the FieldRedirector.

The transformation consists of replacement of all CHECKCAST instructions with trait instantiation and initialization. Only those CHECKCAST instructions are replaces as long as the CHECKCAST's type is a trait, ie. it is annotated by Trait annotation.

The other task of the transformation is transformin trait classes into the semantics of the FieldRedirector. It consists of recognition whether the class is annotated by Trait annotation. If it is so the transformer generates the self field whose type is the type of the trait's target class as is given by the value property of the annotation. The self field is annotated by FromContext annotation where the context id is the trait's class itself. Then the transformation annotates all methods in the trait class by DynaContext as follows:

      before:

      private void someMethod() {
      }

      private static void someStaticMethod() {
      }

      after:

      @DynaContext(id=TheTrait.class, attr=ContextAttribute.This)
      private void someMethod() {
      }

      @DynaContext(id=TheTrait.class, attr=ContextAttribute.Mandatory)
      private static void someStaticMethod() {
      }

 

Since:

Mar 21, 2009 2:37:32 PM

Author:

Zbynek Slajchrt

Field Summary

static String

TRAIT_ANNOT_DESC

Fields inherited from class org.objectweb.asm.ClassAdapter

cv

Constructor Summary

TraitTransformer(org.objectweb.asm.ClassVisitor cv, org.objectweb.asm.tree.ClassNode classNode)

Method Summary

void	visit(int version, int access, String name, String signature, String superName, String[] interfaces)
org.objectweb.asm.AnnotationVisitor	visitAnnotation(String desc, boolean visible)
void	visitEnd()
org.objectweb.asm.FieldVisitor	visitField(int access, String name, String desc, String signature, Object value)
org.objectweb.asm.MethodVisitor	visitMethod(int access, String name, String desc, String signature, String[] exceptions)

Methods inherited from class org.objectweb.asm.ClassAdapter

visitAttribute, visitInnerClass, visitOuterClass, visitSource

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

TRAIT_ANNOT_DESC

public static String TRAIT_ANNOT_DESC

Constructor Detail

TraitTransformer

public TraitTransformer(org.objectweb.asm.ClassVisitor cv,
                        org.objectweb.asm.tree.ClassNode classNode)

Method Detail

visit

public void visit(int version,
                  int access,
                  String name,
                  String signature,
                  String superName,
                  String[] interfaces)

Specified by:

visit in interface org.objectweb.asm.ClassVisitor

Overrides:

visit in class org.objectweb.asm.ClassAdapter

visitAnnotation

public org.objectweb.asm.AnnotationVisitor visitAnnotation(String desc,
                                                           boolean visible)

Specified by:

visitAnnotation in interface org.objectweb.asm.ClassVisitor

Overrides:

visitAnnotation in class org.objectweb.asm.ClassAdapter

visitField

public org.objectweb.asm.FieldVisitor visitField(int access,
                                                 String name,
                                                 String desc,
                                                 String signature,
                                                 Object value)

Specified by:

visitField in interface org.objectweb.asm.ClassVisitor

Overrides:

visitField in class org.objectweb.asm.ClassAdapter

visitEnd

public void visitEnd()

Specified by:

visitEnd in interface org.objectweb.asm.ClassVisitor

Overrides:

visitEnd in class org.objectweb.asm.ClassAdapter

visitMethod

public org.objectweb.asm.MethodVisitor visitMethod(int access,
                                                   String name,
                                                   String desc,
                                                   String signature,
                                                   String[] exceptions)

Specified by:

visitMethod in interface org.objectweb.asm.ClassVisitor

Overrides:

visitMethod in class org.objectweb.asm.ClassAdapter