/*

 * Copyright (c) 2013, 2019, 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.

 *

 * 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 org.graalvm.compiler.hotspot.phases;

import static org.graalvm.compiler.nodes.ConstantNode.getConstantNodes;

import org.graalvm.compiler.nodes.ConstantNode;

import org.graalvm.compiler.nodes.StructuredGraph;

import org.graalvm.compiler.nodes.spi.CoreProviders;

import org.graalvm.compiler.nodes.type.StampTool;

import org.graalvm.compiler.phases.VerifyPhase;

import jdk.vm.ci.hotspot.HotSpotObjectConstant;

import jdk.vm.ci.meta.JavaKind;

/**

 * Checks for {@link #isIllegalObjectConstant(ConstantNode) illegal} object constants in a graph

 * processed for AOT compilation.

 *

 * @see LoadJavaMirrorWithKlassPhase

 */

public class AheadOfTimeVerificationPhase extends VerifyPhase<CoreProviders> {

    @Override

    protected void verify(StructuredGraph graph, CoreProviders context) {

        for (ConstantNode node : getConstantNodes(graph)) {

            if (isIllegalObjectConstant(node)) {

                throw new VerificationError("illegal object constant: " + node);

            }

        }

    }

    public static boolean isIllegalObjectConstant(ConstantNode node) {

        return isObject(node) &&

                        !isNullReference(node) &&

                        !isInternedString(node) &&

                        !isDirectMethodHandle(node) &&

                        !isBoundMethodHandle(node) &&

                        !isVarHandle(node);

    }

    private static boolean isObject(ConstantNode node) {

        return node.getStackKind() == JavaKind.Object;

    }

    private static boolean isNullReference(ConstantNode node) {

        return isObject(node) && node.isNullConstant();

    }

    private static boolean isDirectMethodHandle(ConstantNode node) {

        if (!isObject(node)) {

            return false;

        }

        return "Ljava/lang/invoke/DirectMethodHandle;".equals(StampTool.typeOrNull(node).getName());

    }

    private static boolean isBoundMethodHandle(ConstantNode node) {

        if (!isObject(node)) {

            return false;

        }

        return StampTool.typeOrNull(node).getName().startsWith("Ljava/lang/invoke/BoundMethodHandle");

    }

    private static boolean isVarHandle(ConstantNode node) {

        if (!isObject(node)) {

            return false;

        }

        String name = StampTool.typeOrNull(node).getName();

        return name.equals("Ljava/lang/invoke/VarHandle$AccessDescriptor;");

    }

    private static boolean isInternedString(ConstantNode node) {

        if (!isObject(node)) {

            return false;

        }

        HotSpotObjectConstant c = (HotSpotObjectConstant) node.asConstant();

        return c.isInternedString();

    }

}