/*
 * Copyright (c) 2012, 2014, 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.hotspot.nodes;

import com.oracle.graal.api.meta.*;
import com.oracle.graal.graph.*;
import com.oracle.graal.nodeinfo.*;
import com.oracle.graal.nodes.calc.*;
import com.oracle.graal.nodes.spi.*;
import com.oracle.graal.word.*;

/**
 * Converts a compile-time constant Java string into a C string installed with the generated code.
 */
@NodeInfo
public final class CStringNode extends FloatingNode implements LIRLowerable {

    public static final NodeClass<CStringNode> TYPE = NodeClass.create(CStringNode.class);
    protected final String string;

    public CStringNode(String string) {
        super(TYPE, null);
        this.string = string;
    }

    public void generate(NodeLIRBuilderTool gen) {
        gen.setResult(this, emitCString(gen, string));
    }

    public static AllocatableValue emitCString(NodeLIRBuilderTool gen, String value) {
        AllocatableValue dst = gen.getLIRGeneratorTool().newVariable(LIRKind.value(gen.getLIRGeneratorTool().target().wordKind));
        gen.getLIRGeneratorTool().emitData(dst, toCString(value));
        return dst;
    }

    /**
     * Converts a string to a null terminated byte array of ASCII characters.
     *
     * @param s a String that must only contain ASCII characters
     */
    public static byte[] toCString(String s) {
        byte[] bytes = new byte[s.length() + 1];
        for (int i = 0; i < s.length(); i++) {
            assert s.charAt(i) < 128 : "non-ascii string: " + s;
            bytes[i] = (byte) s.charAt(i);
        }
        bytes[s.length()] = 0;
        return bytes;
    }

    @NodeIntrinsic(setStampFromReturnType = true)
    public static native Word cstring(@ConstantNodeParameter String string);
}