bytecodehelper.java

大名鼎鼎的java动态脚本语言。已经通过了sun的认证

/*
 $Id: BytecodeHelper.java,v 1.30 2006/06/25 18:52:00 blackdrag Exp $

 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 java.math.BigDecimal;
import java.math.BigInteger;

import org.codehaus.groovy.ast.ClassHelper;
import org.codehaus.groovy.ast.ClassNode;
import org.codehaus.groovy.ast.FieldNode;
import org.codehaus.groovy.ast.Parameter;
import org.codehaus.groovy.runtime.ScriptBytecodeAdapter;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.Label;

/**
 * A helper class for bytecode generation with AsmClassGenerator.
 * 
 * @author <a href="mailto:[e-mail]">James Strachan</a>
 * @author <a href="mailto:[e-mail]">Bing Ran</a>
 * @version $Revision: 1.30 $
 */
public class BytecodeHelper implements Opcodes {

    private MethodVisitor cv;

    public MethodVisitor getMethodVisitor() {
        return cv;
    }

    public BytecodeHelper(MethodVisitor cv) {
        this.cv = cv;
    }
    
    /**
     * box the primitive value on the stack
     * @param cls
     */
    public void quickBoxIfNecessary(ClassNode type) {
        String descr = getTypeDescription(type);
        if (type == ClassHelper.boolean_TYPE) {
            boxBoolean();
        }
        else if (ClassHelper.isPrimitiveType(type) && type != ClassHelper.VOID_TYPE) {
            // use a special integer pool in the invokerhelper
            if (type == ClassHelper.int_TYPE) {
                cv.visitMethodInsn(
                        INVOKESTATIC,
                        getClassInternalName(ScriptBytecodeAdapter.class.getName()),
                        "integerValue",
                        "(I)Ljava/lang/Integer;"
                );
                return;
            }

            ClassNode wrapper = ClassHelper.getWrapper(type);
            String internName = getClassInternalName(wrapper);
            cv.visitTypeInsn(NEW, internName);
            cv.visitInsn(DUP);
            if (type==ClassHelper.double_TYPE || type==ClassHelper.long_TYPE) {
                cv.visitInsn(DUP2_X2);
                cv.visitInsn(POP2);
            } else {
                cv.visitInsn(DUP2_X1);
                cv.visitInsn(POP2);
            }
            cv.visitMethodInsn(INVOKESPECIAL, internName, "<init>", "(" + descr + ")V");

//            Operand opr = new Operand(ITEM_Object, wrapperName, "", "");
//            _safePop();
//            push(opr);
        }
    }
    public void quickUnboxIfNecessary(ClassNode type){
        if (ClassHelper.isPrimitiveType(type) && type != ClassHelper.VOID_TYPE) { // todo care when BigDecimal or BigIneteger on stack
            ClassNode wrapper = ClassHelper.getWrapper(type);
            String internName = getClassInternalName(wrapper);
            if (type == ClassHelper.boolean_TYPE) {
                cv.visitTypeInsn(CHECKCAST, internName);
                cv.visitMethodInsn(INVOKEVIRTUAL, internName, type.getName() + "Value", "()" + getTypeDescription(type));
            } else { // numbers
                cv.visitTypeInsn(CHECKCAST, "java/lang/Number");
                cv.visitMethodInsn(INVOKEVIRTUAL, /*internName*/"java/lang/Number", type.getName() + "Value", "()" + getTypeDescription(type));
            }
        }
    }
    
    /**
     * Generates the bytecode to autobox the current value on the stack
     */
    public void box(Class type) {
        if (type.isPrimitive() && type != void.class) {
            String returnString = "(" + getTypeDescription(type) + ")Ljava/lang/Object;";
            cv.visitMethodInsn(INVOKESTATIC, getClassInternalName(ScriptBytecodeAdapter.class.getName()), "box", returnString);
        }
    }

    public void box(ClassNode type) {
        if (type.isPrimaryClassNode()) return;
        box(type.getTypeClass());
    }

    /**
     * Generates the bytecode to unbox the current value on the stack
     */
    public void unbox(Class type) {
        if (type.isPrimitive() && type != Void.TYPE) {
            String returnString = "(Ljava/lang/Object;)" + getTypeDescription(type);
            cv.visitMethodInsn(
                INVOKESTATIC,
                getClassInternalName(ScriptBytecodeAdapter.class.getName()),
                type.getName() + "Unbox",
                returnString);
        }
    }
    
    public void unbox(ClassNode type) {
        if (type.isPrimaryClassNode()) return;
        unbox(type.getTypeClass());
    }

    public static String getClassInternalName(ClassNode t){
    	if (t.isPrimaryClassNode()){
    		return getClassInternalName(t.getName());
    	}
        return getClassInternalName(t.getTypeClass());
    }
    
    public static String getClassInternalName(Class t) {
        return org.objectweb.asm.Type.getInternalName(t);
    }
    
    /**
     * @return the ASM internal name of the type
     */
    public static String getClassInternalName(String name) {
        return name.replace('.', '/');
    }
    
    /**
     * @return the ASM method type descriptor
     */
    public static String getMethodDescriptor(ClassNode returnType, Parameter[] parameters) {
        StringBuffer buffer = new StringBuffer("(");
        for (int i = 0; i < parameters.length; i++) {
            buffer.append(getTypeDescription(parameters[i].getType()));
        }
        buffer.append(")");
        buffer.append(getTypeDescription(returnType));
        return buffer.toString();
    }

    /**
     * @return the ASM method type descriptor
     */
    public static String getMethodDescriptor(Class returnType, Class[] paramTypes) {
        // lets avoid class loading
        StringBuffer buffer = new StringBuffer("(");
        for (int i = 0; i < paramTypes.length; i++) {
            buffer.append(getTypeDescription(paramTypes[i]));
        }
        buffer.append(")");
        buffer.append(getTypeDescription(returnType));
        return buffer.toString();
    }

    public static String getTypeDescription(Class c) {
        return org.objectweb.asm.Type.getDescriptor(c);
    }
    
    /**
     * array types are special:
     * eg.: String[]: classname: [Ljava.lang.String;
     *      Object:   classname: java.lang.Object
     *      int[] :   classname: [I
     * unlike getTypeDescription '.' is not replaces by '/'. 
     * it seems that makes problems for
     * the class loading if '.' is replaced by '/'
     * @return the ASM type description for class loading
     */
    public static String getClassLoadingTypeDescription(ClassNode c) {
        StringBuffer buf = new StringBuffer();
        boolean array = false;
        while (true) {
            if (c.isArray()) {
                buf.append('[');
                c = c.getComponentType();
                array = true;
            } else {
                if (ClassHelper.isPrimitiveType(c)) {
                    buf.append(getTypeDescription(c));
                } else {
                    if (array) buf.append('L');
                    buf.append(c.getName());
                    if(array) buf.append(';');
                }
                return buf.toString();
            }
        }
    }
    
    /**
     * array types are special:
     * eg.: String[]: classname: [Ljava/lang/String;
     *      int[]: [I
     * @return the ASM type description
     */
    public static String getTypeDescription(ClassNode c) {
        StringBuffer buf = new StringBuffer();
        ClassNode d = c;
        while (true) {
            if (ClassHelper.isPrimitiveType(d)) {
                char car;
                if (d == ClassHelper.int_TYPE) {
                    car = 'I';
                } else if (d == ClassHelper.VOID_TYPE) {
                    car = 'V';
                } else if (d == ClassHelper.boolean_TYPE) {
                    car = 'Z';
                } else if (d == ClassHelper.byte_TYPE) {
                    car = 'B';
                } else if (d == ClassHelper.char_TYPE) {
                    car = 'C';
                } else if (d == ClassHelper.short_TYPE) {
                    car = 'S';
                } else if (d == ClassHelper.double_TYPE) {
                    car = 'D';
                } else if (d == ClassHelper.float_TYPE) {
                    car = 'F';
                } else /* long */{
                    car = 'J';
                }
                buf.append(car);
                return buf.toString();
            } else if (d.isArray()) {
                buf.append('[');
                d = d.getComponentType();
            } else {
                buf.append('L');
                String name = d.getName();
                int len = name.length();
                for (int i = 0; i < len; ++i) {
                    char car = name.charAt(i);
                    buf.append(car == '.' ? '/' : car);
                }
                buf.append(';');
                return buf.toString();
            }
        }
    }

    /**
     * @return an array of ASM internal names of the type
     */
    public static String[] getClassInternalNames(ClassNode[] names) {
        int size = names.length;
        String[] answer = new String[size];
        for (int i = 0; i < size; i++) {
            answer[i] = getClassInternalName(names[i]);
        }
        return answer;
    }

    protected void pushConstant(boolean value) {
        if (value) {
            cv.visitInsn(ICONST_1);
        }
        else {
            cv.visitInsn(ICONST_0);
        }
    }

    protected void pushConstant(int value) {
        switch (value) {
            case 0 :
                cv.visitInsn(ICONST_0);
                break;
            case 1 :
                cv.visitInsn(ICONST_1);
                break;
            case 2 :
                cv.visitInsn(ICONST_2);
                break;
            case 3 :
                cv.visitInsn(ICONST_3);
                break;
            case 4 :
                cv.visitInsn(ICONST_4);
                break;
            case 5 :
                cv.visitInsn(ICONST_5);
                break;
            default :
                if (value >= Byte.MIN_VALUE && value <= Byte.MAX_VALUE) {
                    cv.visitIntInsn(BIPUSH, value);
                }