/*

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

/*

 * This file is available under and governed by the GNU General Public

 * License version 2 only, as published by the Free Software Foundation.

 * However, the following notice accompanied the original version of this

 * file:

 *

 * 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 jdk.internal.org.objectweb.asm.commons;

import java.util.Collections;

import java.util.Comparator;

import jdk.internal.org.objectweb.asm.MethodVisitor;

import jdk.internal.org.objectweb.asm.Opcodes;

import jdk.internal.org.objectweb.asm.tree.MethodNode;

import jdk.internal.org.objectweb.asm.tree.TryCatchBlockNode;

/**

 * A {@link MethodVisitor} adapter to sort the exception handlers. The handlers are sorted in a

 * method innermost-to-outermost. This allows the programmer to add handlers without worrying about

 * ordering them correctly with respect to existing, in-code handlers.

 *

 * <p>Behavior is only defined for properly-nested handlers. If any "try" blocks overlap (something

 * that isn't possible in Java code) then this may not do what you want. In fact, this adapter just

 * sorts by the length of the "try" block, taking advantage of the fact that a given try block must

 * be larger than any block it contains).

 *

 * @author Adrian Sampson

 */

public class TryCatchBlockSorter extends MethodNode {

    /**

      * Constructs a new {@link TryCatchBlockSorter}.

      *

      * @param methodVisitor the method visitor to which this visitor must delegate method calls. May

      *     be {@literal null}.

      * @param access the method's access flags (see {@link Opcodes}). This parameter also indicates if

      *     the method is synthetic and/or deprecated.

      * @param name the method's name.

      * @param descriptor the method's descriptor (see {@link jdk.internal.org.objectweb.asm.Type}).

      * @param signature the method's signature. May be {@literal null} if the method parameters,

      *     return type and exceptions do not use generic types.

      * @param exceptions the internal names of the method's exception classes (see {@link

      *     jdk.internal.org.objectweb.asm.Type#getInternalName()}). May be {@literal null}.

      */

    public TryCatchBlockSorter(

            final MethodVisitor methodVisitor,

            final int access,

            final String name,

            final String descriptor,

            final String signature,

            final String[] exceptions) {

        this(

                /* latest api = */ Opcodes.ASM8,

                methodVisitor,

                access,

                name,

                descriptor,

                signature,

                exceptions);

        if (getClass() != TryCatchBlockSorter.class) {

            throw new IllegalStateException();

        }

    }

    protected TryCatchBlockSorter(

            final int api,

            final MethodVisitor methodVisitor,

            final int access,

            final String name,

            final String descriptor,

            final String signature,

            final String[] exceptions) {

        super(api, access, name, descriptor, signature, exceptions);

        this.mv = methodVisitor;

    }

    @Override

    public void visitEnd() {

        // Sort the TryCatchBlockNode elements by the length of their "try" block.

        Collections.sort(

                tryCatchBlocks,

                new Comparator<TryCatchBlockNode>() {

                    @Override

                    public int compare(

                            final TryCatchBlockNode tryCatchBlockNode1,

                            final TryCatchBlockNode tryCatchBlockNode2) {

                        return blockLength(tryCatchBlockNode1) - blockLength(tryCatchBlockNode2);

                    }

                    private int blockLength(final TryCatchBlockNode tryCatchBlockNode) {

                        int startIndex = instructions.indexOf(tryCatchBlockNode.start);

                        int endIndex = instructions.indexOf(tryCatchBlockNode.end);

                        return endIndex - startIndex;

                    }

                });

        // Update the 'target' of each try catch block annotation.

        for (int i = 0; i < tryCatchBlocks.size(); ++i) {

            tryCatchBlocks.get(i).updateIndex(i);

        }

        if (mv != null) {

            accept(mv);

        }

    }

}