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 * 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.phases.verify;

import org.graalvm.compiler.debug.GraalError;

import org.graalvm.compiler.graph.Graph;

import org.graalvm.compiler.graph.Node;

import org.graalvm.compiler.nodes.ConstantNode;

import org.graalvm.compiler.nodes.Invoke;

import org.graalvm.compiler.nodes.ParameterNode;

import org.graalvm.compiler.nodes.PiNode;

import org.graalvm.compiler.nodes.StructuredGraph;

import org.graalvm.compiler.nodes.ValueNode;

import org.graalvm.compiler.nodes.ValuePhiNode;

import org.graalvm.compiler.nodes.ValueProxyNode;

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

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

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

import org.graalvm.compiler.phases.VerifyPhase;

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

public class VerifyGraphAddUsage extends VerifyPhase<PhaseContext> {

    private static final Method ADD_OR_UNIQUE;

    private static final Method CONSTRUCTOR_NEW_INSTANCE;

    private static final EconomicSet<Class<?>> ALLOWED_CLASSES = EconomicSet.create();

    static {

        try {

            ADD_OR_UNIQUE = Graph.class.getDeclaredMethod("addOrUnique", Node.class);

            CONSTRUCTOR_NEW_INSTANCE = Constructor.class.getDeclaredMethod("newInstance", Object[].class);

        } catch (NoSuchMethodException e) {

            throw new GraalError(e);

        }

        ALLOWED_CLASSES.add(Graph.class);

        ALLOWED_CLASSES.add(LoweringProvider.class);

    }

    @Override

    protected boolean verify(StructuredGraph graph, PhaseContext context) {

        boolean allowed = false;

        for (Class<?> cls : ALLOWED_CLASSES) {

            ResolvedJavaType declaringClass = graph.method().getDeclaringClass();

            if (context.getMetaAccess().lookupJavaType(cls).isAssignableFrom(declaringClass)) {

                allowed = true;

            }

        }

        if (!allowed) {

            ResolvedJavaMethod addOrUniqueMethod = context.getMetaAccess().lookupJavaMethod(ADD_OR_UNIQUE);

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

                ResolvedJavaMethod callee = t.targetMethod();

                if (callee.equals(addOrUniqueMethod)) {

                    ValueNode nodeArgument = t.arguments().get(1);

                    EconomicSet<Node> seen = EconomicSet.create();

                    checkNonFactory(graph, seen, context, nodeArgument);

                }

            }

        }

        return true;

    }

    private void checkNonFactory(StructuredGraph graph, EconomicSet<Node> seen, PhaseContext context, ValueNode node) {

        if (seen.contains(node)) {

            return;

        }

        seen.add(node);

        // Check where the value came from recursively, or if it is allowed.

        if (node instanceof ValuePhiNode) {

            for (ValueNode input : ((ValuePhiNode) node).values()) {

                checkNonFactory(graph, seen, context, input);

            }

        } else if (node instanceof PiNode) {

            checkNonFactory(graph, seen, context, ((PiNode) node).object());

        } else if (node instanceof ParameterNode) {

            return;

        } else if (node instanceof ConstantNode) {

            return;

        } else if (node instanceof ValueProxyNode) {

            checkNonFactory(graph, seen, context, ((ValueProxyNode) node).value());

        } else if (node instanceof Invoke && ((Invoke) node).callTarget().targetMethod().equals(context.getMetaAccess().lookupJavaMethod(CONSTRUCTOR_NEW_INSTANCE))) {

            return;

        } else if (!(node instanceof NewInstanceNode)) {

            // In all other cases, the argument must be a new instance.

            throw new VerificationError("Must add node '%s' with inputs in method '%s' of class '%s'.",

                            node, graph.method().getName(), graph.method().getDeclaringClass().getName());

        }

    }

}