/*
 * Copyright (c) 2015, 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.replacements;

import com.oracle.graal.api.meta.*;
import com.oracle.graal.api.replacements.*;
import com.oracle.graal.compiler.common.type.*;
import com.oracle.graal.java.*;
import com.oracle.graal.java.GraphBuilderPlugin.ParameterPlugin;
import com.oracle.graal.nodes.*;
import com.oracle.graal.nodes.calc.*;

/**
 * A {@link ParameterPlugin} that binds constant values to some parameters.
 */
public class ConstantBindingParameterPlugin implements ParameterPlugin {
    private final Object[] constantArgs;
    private final ParameterPlugin delegate;
    private final MetaAccessProvider metaAccess;
    private final SnippetReflectionProvider snippetReflection;

    /**
     * Creates a plugin that will create {@link ConstantNode}s for each parameter with an index
     * equal to that of a non-null object in {@code constantArgs} (from which the
     * {@link ConstantNode} is created if it isn't already a {@link ConstantNode}). For all other
     * parameter indexes, {@code delegate} is applied if it is non-null.
     */
    public ConstantBindingParameterPlugin(Object[] constantArgs, ParameterPlugin delegate, MetaAccessProvider metaAccess, SnippetReflectionProvider snippetReflection) {
        this.constantArgs = constantArgs;
        this.delegate = delegate;
        this.metaAccess = metaAccess;
        this.snippetReflection = snippetReflection;
    }

    public FloatingNode interceptParameter(GraphBuilderContext b, int index, Stamp stamp) {
        Object arg = constantArgs[index];
        if (arg != null) {
            ConstantNode constantNode;
            if (arg instanceof ConstantNode) {
                constantNode = (ConstantNode) arg;
            } else if (arg instanceof Constant) {
                constantNode = ConstantNode.forConstant(stamp, (Constant) arg, metaAccess);
            } else {
                constantNode = ConstantNode.forConstant(snippetReflection.forBoxed(stamp.getStackKind(), arg), metaAccess);
            }
            return constantNode;
        }
        if (delegate != null) {
            return delegate.interceptParameter(b, index, stamp);
        }
        return null;
    }
}