// 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.eclipse.persistence.internal.libraries.asm.commons;

import org.eclipse.persistence.internal.libraries.asm.ClassVisitor;
import org.eclipse.persistence.internal.libraries.asm.MethodVisitor;
import org.eclipse.persistence.internal.libraries.asm.Opcodes;

/**
 * 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.ASM6, 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();
  }
}
