ASM: a very small and fast Java bytecode manipulation framework
Copyright (c) 2000-2011 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
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SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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THE POSSIBILITY OF SUCH DAMAGE.
/***
 * ASM: a very small and fast Java bytecode manipulation framework
 * Copyright (c) 2000-2011 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.objectweb.asm.commons;

import org.objectweb.asm.ClassVisitor;
import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;

A ClassVisitor that merges clinit methods into a single one. 
Author:
Eric Bruneton/**
 * A {@link ClassVisitor} that merges clinit methods into a single one.
 * 
 * @author Eric Bruneton
 */
public class StaticInitMerger extends ClassVisitor {

    private String name;

    private MethodVisitor clinit;

    private final String prefix;

    private int counter;

    public StaticInitMerger(final String prefix, final ClassVisitor cv) {
        this(Opcodes.ASM5, prefix, cv);
    }

    protected StaticInitMerger(final int api, final String prefix,
            final ClassVisitor cv) {
        super(api, cv);
        this.prefix = prefix;
    }

    @Override
    public void visit(final int version, final int access, final String name,
            final String signature, final String superName,
            final String[] interfaces) {
        cv.visit(version, access, name, signature, superName, interfaces);
        this.name = name;
    }

    @Override
    public MethodVisitor visitMethod(final int access, final String name,
            final String desc, final String signature, final String[] exceptions) {
        MethodVisitor mv;
        if ("<clinit>".equals(name)) {
            int a = Opcodes.ACC_PRIVATE + Opcodes.ACC_STATIC;
            String n = prefix + counter++;
            mv = cv.visitMethod(a, n, desc, signature, exceptions);

            if (clinit == null) {
                clinit = cv.visitMethod(a, name, desc, null, null);
            }
            clinit.visitMethodInsn(Opcodes.INVOKESTATIC, this.name, n, desc,
                    false);
        } else {
            mv = cv.visitMethod(access, name, desc, signature, exceptions);
        }
        return mv;
    }

    @Override
    public void visitEnd() {
        if (clinit != null) {
            clinit.visitInsn(Opcodes.RETURN);
            clinit.visitMaxs(0, 0);
        }
        cv.visitEnd();
    }
}