/*
 * Copyright (c) 2009, 2011, 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 com.oracle.graal.nodes.java;

import com.oracle.graal.api.meta.*;
import com.oracle.graal.graph.*;
import com.oracle.graal.nodes.*;
import com.oracle.graal.nodes.spi.*;
import com.oracle.graal.nodes.type.*;

/**
 * Implements a type check where the type being checked is loaded at runtime. This is used, for
 * instance, to implement an object array store check.
 */
public final class CheckCastDynamicNode extends FixedWithNextNode implements Canonicalizable, Lowerable, Node.IterableNodeType {

    @Input private ValueNode object;
    @Input private ValueNode type;

    /**
     * Determines the exception thrown by this node if the check fails: {@link ClassCastException}
     * if false; {@link ArrayStoreException} if true.
     */
    private final boolean forStoreCheck;

    /**
     * @param type the type being cast to
     * @param object the instruction producing the object
     */
    public CheckCastDynamicNode(ValueNode type, ValueNode object, boolean forStoreCheck) {
        super(object.stamp());
        this.type = type;
        this.object = object;
        this.forStoreCheck = forStoreCheck;
        assert type.kind() == Kind.Object;
        assert type.objectStamp().isExactType();
        assert type.objectStamp().type().getName().equals("Ljava/lang/Class;");
    }

    public boolean isForStoreCheck() {
        return forStoreCheck;
    }

    @Override
    public void lower(LoweringTool tool, LoweringType loweringType) {
        tool.getRuntime().lower(this, tool);
    }

    @Override
    public boolean inferStamp() {
        if (object().stamp().nonNull() && !stamp().nonNull()) {
            setStamp(StampFactory.objectNonNull());
            return true;
        }
        return super.inferStamp();
    }

    @Override
    public ValueNode canonical(CanonicalizerTool tool) {
        assert object() != null : this;

        if (object().objectStamp().alwaysNull()) {
            return object();
        }
        if (type().isConstant()) {
            Class clazz = (Class) type().asConstant().asObject();
            ResolvedJavaType t = tool.runtime().lookupJavaType(clazz);
            return graph().add(new CheckCastNode(t, object(), null, forStoreCheck));
        }
        return this;
    }

    public ValueNode object() {
        return object;
    }

    /**
     * Gets the runtime-loaded type being cast to.
     */
    public ValueNode type() {
        return type;
    }

    @NodeIntrinsic
    public static native <T> T checkCastDynamic(Class<T> type, Object object, @ConstantNodeParameter boolean forStoreCheck);
}