dummyclassgenerator.java

来自「Groovy动态语言 运行在JVM中的动态语言 可以方便的处理业务逻辑变化大的业」· Java 代码 · 共 191 行

/*
 * $Id: DummyClassGenerator.java 3419 2006-01-19 00:07:02Z blackdrag $
 *
 * Copyright 2003 (C) James Strachan and Bob Mcwhirter. All Rights Reserved.
 *
 * Redistribution and use of this software and associated documentation
 * ("Software"), with or without modification, are permitted provided that the
 * following conditions are met: 1. Redistributions of source code must retain
 * copyright statements and notices. Redistributions must also contain a copy
 * of this document. 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 name "groovy" must not be used to endorse or promote products derived
 * from this Software without prior written permission of The Codehaus. For
 * written permission, please contact [e-mail]. 4. Products derived
 * from this Software may not be called "groovy" nor may "groovy" appear in
 * their names without prior written permission of The Codehaus. "groovy" is a
 * registered trademark of The Codehaus. 5. Due credit should be given to The
 * Codehaus - http://groovy.codehaus.org/
 *
 * THIS SOFTWARE IS PROVIDED BY THE CODEHAUS AND CONTRIBUTORS ``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 CODEHAUS 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.
 *
 */
package org.codehaus.groovy.classgen;

import groovy.lang.GroovyRuntimeException;
import org.codehaus.groovy.ast.*;
import org.objectweb.asm.ClassVisitor;
import org.objectweb.asm.MethodVisitor;

import java.util.*;

/**
 * To generate a class that has all the fields and methods, except that fields are not initilized
 * and methods are empty. It's intended for being used as a place holder during code generation
 * of reference to the "this" class itself.
 *
 * @author <a href="mailto:[e-mail]">James Strachan</a>
 * @author <a href="mailto:[e-mail]">Bing Ran</a>
 *
 * @version $Revision: 3419 $
 */
public class DummyClassGenerator extends ClassGenerator {

    private ClassVisitor cw;
    private MethodVisitor cv;
    private GeneratorContext context;

    private String sourceFile;

    // current class details
    private ClassNode classNode;
    private String internalClassName;
    private String internalBaseClassName;


    public DummyClassGenerator(
        GeneratorContext context,
        ClassVisitor classVisitor,
        ClassLoader classLoader,
        String sourceFile) {
        super(classLoader);
        this.context = context;
        this.cw = classVisitor;
        this.sourceFile = sourceFile;
    }

    // GroovyClassVisitor interface
    //-------------------------------------------------------------------------
    public void visitClass(ClassNode classNode) {
        try {
            this.classNode = classNode;
            this.internalClassName = BytecodeHelper.getClassInternalName(classNode);

            //System.out.println("Generating class: " + classNode.getName());

            this.internalBaseClassName = BytecodeHelper.getClassInternalName(classNode.getSuperClass());

            cw.visit(
                asmJDKVersion,
                classNode.getModifiers(),
                internalClassName,
                (String)null,
                internalBaseClassName,
                BytecodeHelper.getClassInternalNames(classNode.getInterfaces())
                );

            classNode.visitContents(this);

            for (Iterator iter = innerClasses.iterator(); iter.hasNext();) {
                ClassNode innerClass = (ClassNode) iter.next();
                ClassNode innerClassType = innerClass;
                String innerClassInternalName = BytecodeHelper.getClassInternalName(innerClassType);
                String outerClassName = internalClassName; // default for inner classes
                MethodNode enclosingMethod = innerClass.getEnclosingMethod();
                if (enclosingMethod != null) {
                    // local inner classes do not specify the outer class name
                    outerClassName = null;
                }
                cw.visitInnerClass(
                    innerClassInternalName,
                    outerClassName,
                    innerClassType.getName(),
                    innerClass.getModifiers());
            }
            cw.visitEnd();
        }
        catch (GroovyRuntimeException e) {
            e.setModule(classNode.getModule());
            throw e;
        }
    }

    public void visitConstructor(ConstructorNode node) {

        visitParameters(node, node.getParameters());

        String methodType = BytecodeHelper.getMethodDescriptor(ClassHelper.VOID_TYPE, node.getParameters());
        cv = cw.visitMethod(node.getModifiers(), "<init>", methodType, null, null);
        cv.visitTypeInsn(NEW, "java/lang/RuntimeException");
        cv.visitInsn(DUP);
        cv.visitLdcInsn("not intended for execution");
        cv.visitMethodInsn(INVOKESPECIAL, "java/lang/RuntimeException", "<init>", "(Ljava/lang/String;)V");
        cv.visitInsn(ATHROW);
        cv.visitMaxs(0, 0);
    }

    public void visitMethod(MethodNode node) {

        visitParameters(node, node.getParameters());

        String methodType = BytecodeHelper.getMethodDescriptor(node.getReturnType(), node.getParameters());
        cv = cw.visitMethod(node.getModifiers(), node.getName(), methodType, null, null);

        cv.visitTypeInsn(NEW, "java/lang/RuntimeException");
        cv.visitInsn(DUP);
        cv.visitLdcInsn("not intended for execution");
        cv.visitMethodInsn(INVOKESPECIAL, "java/lang/RuntimeException", "<init>", "(Ljava/lang/String;)V");
        cv.visitInsn(ATHROW);

        cv.visitMaxs(0, 0);
    }

    public void visitField(FieldNode fieldNode) {

        cw.visitField(
            fieldNode.getModifiers(),
            fieldNode.getName(),
            BytecodeHelper.getTypeDescription(fieldNode.getType()),
            null, //fieldValue,  //br  all the sudden that one cannot init the field here. init is done in static initilizer and instace intializer.
            null);
    }

    /**
     * Creates a getter, setter and field
     */
    public void visitProperty(PropertyNode statement) {
    }
    
    protected CompileUnit getCompileUnit() {
        CompileUnit answer = classNode.getCompileUnit();
        if (answer == null) {
            answer = context.getCompileUnit();
        }
        return answer;
    }

    protected void visitParameters(ASTNode node, Parameter[] parameters) {
        for (int i = 0, size = parameters.length; i < size; i++ ) {
            visitParameter(node, parameters[i]);
        }
    }

    protected void visitParameter(ASTNode node, Parameter parameter) {
    }


    public void visitAnnotations(AnnotatedNode node) {
    }
}