/*

 * Copyright (c) 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.

 *

 * 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

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 */

package org.graalvm.compiler.core.test;

import java.util.Map;

import java.util.concurrent.ConcurrentHashMap;

import java.util.stream.Collectors;

import org.graalvm.compiler.api.replacements.Fold;

import org.graalvm.compiler.nodes.StructuredGraph;

import org.graalvm.compiler.nodes.graphbuilderconf.GeneratedInvocationPlugin;

import org.graalvm.compiler.nodes.java.MethodCallTargetNode;

import org.graalvm.compiler.phases.VerifyPhase;

import org.graalvm.compiler.phases.tiers.PhaseContext;

import jdk.vm.ci.meta.ResolvedJavaMethod;

import jdk.vm.ci.meta.ResolvedJavaType;

/**

 * Verifies that all {@link Fold} annotated methods have at least one caller.

 */

public class VerifyFoldableMethods extends VerifyPhase<PhaseContext> {

    @Override

    public boolean checkContract() {

        return false;

    }

    private final Map<ResolvedJavaMethod, Boolean> foldables = new ConcurrentHashMap<>();

    ResolvedJavaType generatedInvocationPluginType;

    @Override

    protected boolean verify(StructuredGraph graph, PhaseContext context) {

        ResolvedJavaMethod method = graph.method();

        if (method.getAnnotation(Fold.class) != null) {

            foldables.putIfAbsent(method, false);

        } else {

            if (generatedInvocationPluginType == null) {

                generatedInvocationPluginType = context.getMetaAccess().lookupJavaType(GeneratedInvocationPlugin.class);

            }

            if (!generatedInvocationPluginType.isAssignableFrom(method.getDeclaringClass())) {

                for (MethodCallTargetNode t : graph.getNodes(MethodCallTargetNode.TYPE)) {

                    ResolvedJavaMethod callee = t.targetMethod();

                    if (callee.getAnnotation(Fold.class) != null) {

                        foldables.put(callee, true);

                    }

                }

            }

        }

        return true;

    }

    public void finish() {

        String uncalled = foldables.entrySet().stream().filter(e -> e.getValue() == false).map(e -> e.getKey().format("%H.%n(%p)")).collect(Collectors.joining(System.lineSeparator() + "  "));

        if (uncalled.length() != 0) {

            throw new VerificationError(String.format("Methods annotated with @" + Fold.class.getSimpleName() + " appear to have no usages:%n  %s", uncalled));

        }

    }

}