Package org.ow2.asm.optimizer

Source Code of org.ow2.asm.optimizer.MethodOptimizer

/***
* ASM: a very small and fast Java bytecode manipulation framework
* Copyright (c) 2000-2007 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 org.ow2.asm.optimizer;

import org.ow2.asm.AnnotationVisitor;
import org.ow2.asm.Attribute;
import org.ow2.asm.FieldVisitor;
import org.ow2.asm.Label;
import org.ow2.asm.MethodAdapter;
import org.ow2.asm.MethodVisitor;
import org.ow2.asm.Opcodes;
import org.ow2.asm.Type;
import org.ow2.asm.commons.Remapper;
import org.ow2.asm.commons.RemappingMethodAdapter;

/**
* A {@link MethodAdapter} that renames fields and methods, and removes debug
* info.
*
* @author Eugene Kuleshov
*/
public class MethodOptimizer extends RemappingMethodAdapter implements Opcodes {
   
    private final ClassOptimizer classOptimizer;

    public MethodOptimizer(
        ClassOptimizer classOptimizer,
        int access,
        String desc,
        MethodVisitor mv,
        Remapper remapper)
    {
        super(access, desc, mv, remapper);
        this.classOptimizer = classOptimizer;
    }

    // ------------------------------------------------------------------------
    // Overridden methods
    // ------------------------------------------------------------------------

    @Override
    public AnnotationVisitor visitAnnotationDefault() {
        // remove annotations
        return null;
    }

    @Override
    public AnnotationVisitor visitAnnotation(String desc, boolean visible) {
        // remove annotations
        return null;
    }

    @Override
    public AnnotationVisitor visitParameterAnnotation(
        final int parameter,
        final String desc,
        final boolean visible)
    {
        // remove annotations
        return null;
    }

    @Override
    public void visitLocalVariable(
        final String name,
        final String desc,
        final String signature,
        final Label start,
        final Label end,
        final int index)
    {
        // remove debug info
    }

    @Override
    public void visitLineNumber(final int line, final Label start) {
        // remove debug info
    }

    @Override
    public void visitFrame(
        int type,
        int local,
        Object[] local2,
        int stack,
        Object[] stack2)
    {
        // remove frame info
    }

    @Override
    public void visitAttribute(Attribute attr) {
        // remove non standard attributes
    }

    @Override
    public void visitLdcInsn(Object cst) {
        if (!(cst instanceof Type)) {
            super.visitLdcInsn(cst);
            return;
        }

        // transform Foo.class to foo$(class) for 1.2 compatibility
        String ldcName = ((Type) cst).getInternalName();
        String fieldName = "class$" + ldcName.replace('/', '$');

        FieldVisitor fv = classOptimizer.syntheticFieldVisitor(ACC_STATIC | ACC_SYNTHETIC,
                fieldName, "Ljava/lang/Class;");
        fv.visitEnd();

        if (!classOptimizer.class$) {
            MethodVisitor mv = classOptimizer.visitMethod(ACC_STATIC | ACC_SYNTHETIC,
                    "class$", "(Ljava/lang/String;)Ljava/lang/Class;", null, null);
            mv.visitCode();
            Label l0 = new Label();
            Label l1 = new Label();
            Label l2 = new Label();
            mv.visitTryCatchBlock(l0, l1, l2, "java/lang/ClassNotFoundException");
            mv.visitLabel(l0);
            mv.visitVarInsn(ALOAD, 0);
            mv.visitMethodInsn(INVOKESTATIC,
                    "java/lang/Class",
                    "forName",
                    "(Ljava/lang/String;)Ljava/lang/Class;");
            mv.visitLabel(l1);
            mv.visitInsn(ARETURN);
            mv.visitLabel(l2);
            mv.visitMethodInsn(INVOKEVIRTUAL, "java/lang/ClassNotFoundException", "getMessage", "()Ljava/lang/String;");
            mv.visitVarInsn(ASTORE, 1);
            mv.visitTypeInsn(NEW, "java/lang/NoClassDefFoundError");
            mv.visitInsn(DUP);
            mv.visitVarInsn(ALOAD, 1);
            mv.visitMethodInsn(INVOKESPECIAL,
                    "java/lang/NoClassDefFoundError", "<init>", "(Ljava/lang/String;)V");
            mv.visitInsn(ATHROW);
            mv.visitMaxs(3, 2);
            mv.visitEnd();

            classOptimizer.class$ = true;
        }

        String clsName = classOptimizer.clsName;
        mv.visitFieldInsn(GETSTATIC, clsName, fieldName, "Ljava/lang/Class;");
        Label elseLabel = new Label();
        mv.visitJumpInsn(IFNONNULL, elseLabel);
        mv.visitLdcInsn(ldcName.replace('/', '.'));
        mv.visitMethodInsn(INVOKESTATIC,
                clsName,
                "class$",
                "(Ljava/lang/String;)Ljava/lang/Class;");
        mv.visitInsn(DUP);
        mv.visitFieldInsn(PUTSTATIC, clsName, fieldName, "Ljava/lang/Class;");
        Label endLabel = new Label();
        mv.visitJumpInsn(GOTO, endLabel);
        mv.visitLabel(elseLabel);
        mv.visitFieldInsn(GETSTATIC, clsName, fieldName, "Ljava/lang/Class;");
        mv.visitLabel(endLabel);
    }
}
TOP

Related Classes of org.ow2.asm.optimizer.MethodOptimizer

TOP
Copyright © 2018 www.massapi.com. All rights reserved.
All source code are property of their respective owners. Java is a trademark of Sun Microsystems, Inc and owned by ORACLE Inc. Contact coftware#gmail.com.