/*

 * Copyright (c) 2013, 2018, Oracle and/or its affiliates. All rights reserved.

 * 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.

 */

package jdk.jfr.internal.instrument;

import java.util.ArrayList;

import java.util.List;

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

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

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

import jdk.internal.org.objectweb.asm.commons.LocalVariablesSorter;

import jdk.internal.org.objectweb.asm.commons.Remapper;

import jdk.internal.org.objectweb.asm.commons.SimpleRemapper;

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

import jdk.jfr.internal.LogLevel;

import jdk.jfr.internal.LogTag;

import jdk.jfr.internal.Logger;

/**

 * Class responsible for finding the call to inline and inlining it.

 *

 * This code is heavily influenced by section 3.2.6 "Inline Method" in

 * "Using ASM framework to implement common bytecode transformation patterns",

 * E. Kuleshov, AOSD.07, March 2007, Vancouver, Canada.

 * http://asm.ow2.org/index.html

 */

@Deprecated

final class JIMethodCallInliner extends LocalVariablesSorter {

    private final String oldClass;

    private final String newClass;

    private final MethodNode inlineTarget;

    private final List<CatchBlock> blocks = new ArrayList<>();

    private boolean inlining;

    /**

     * inlineTarget defines the method to inline and also contains the actual

     * code to inline.

     *

     * @param access

     * @param desc

     * @param mv

     * @param inlineTarget

     * @param oldClass

     * @param newClass

     * @param logger

     */

    public JIMethodCallInliner(int access, String desc, MethodVisitor mv,

            MethodNode inlineTarget, String oldClass, String newClass) {

        super(Opcodes.ASM5, access, desc, mv);

        this.oldClass = oldClass;

        this.newClass = newClass;

        this.inlineTarget = inlineTarget;

        Logger.log(LogTag.JFR_SYSTEM_BYTECODE, LogLevel.DEBUG, "MethodCallInliner: targetMethod=" + newClass + "."

                + inlineTarget.name + inlineTarget.desc);

    }

    @Override

    public void visitMethodInsn(int opcode, String owner, String name,

            String desc, boolean itf) {

        // Now we are looking at method call in the source method

        if (!shouldBeInlined(owner, name, desc)) {

            // If this method call should not be inlined, just keep it

            mv.visitMethodInsn(opcode, owner, name, desc, itf);

            return;

        }

        // If the call should be inlined, we create a MethodInliningAdapter

        // The MIA will walk the instructions in the inlineTarget and add them

        // to the current method, doing the necessary name remappings.

        Logger.log(LogTag.JFR_SYSTEM_BYTECODE, LogLevel.DEBUG, "Inlining call to " + name + desc);

        Remapper remapper = new SimpleRemapper(oldClass, newClass);

        Label end = new Label();

        inlining = true;

        inlineTarget.instructions.resetLabels();

        JIMethodInliningAdapter mia = new JIMethodInliningAdapter(this, end,

                opcode == Opcodes.INVOKESTATIC ? Opcodes.ACC_STATIC : 0, desc,

                remapper);

        inlineTarget.accept(mia);

        inlining = false;

        super.visitLabel(end);

    }

    /**

     * Determine if the method should be inlined or not.

     */

    private boolean shouldBeInlined(String owner, String name, String desc) {

        return inlineTarget.desc.equals(desc) && inlineTarget.name.equals(name)

                && owner.equals(newClass.replace('.', '/'));

    }

    @Override

    public void visitTryCatchBlock(Label start, Label end, Label handler,

            String type) {

        if (!inlining) {

            // try-catch blocks are saved here and replayed at the end

            // of the method (in visitMaxs)

            blocks.add(new CatchBlock(start, end, handler, type));

        } else {

            super.visitTryCatchBlock(start, end, handler, type);

        }

    }

    @Override

    public void visitMaxs(int stack, int locals) {

        for (CatchBlock b : blocks) {

            super.visitTryCatchBlock(b.start, b.end, b.handler, b.type);

        }

        super.visitMaxs(stack, locals);

    }

    static final class CatchBlock {

        final Label start;

        final Label end;

        final Label handler;

        final String type;

        CatchBlock(Label start, Label end, Label handler, String type) {

            this.start = start;

            this.end = end;

            this.handler = handler;

            this.type = type;

        }

    }

}