/*
 * Copyright (c) 2014, 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
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 */
package jdk.vm.ci.hotspot;

import static jdk.vm.ci.hotspot.HotSpotJVMCIRuntime.runtime;
import static jdk.vm.ci.hotspot.UnsafeAccess.UNSAFE;
import jdk.internal.misc.Unsafe;

/**
 * Class to access the C++ {@code vmSymbols} table.
 */
final class HotSpotVmSymbols {

    /**
     * Returns the symbol in the {@code vmSymbols} table at position {@code index} as {@link String}
     * .
     *
     * @param index position in the symbol table
     * @return the symbol at position id
     */
    static String symbolAt(int index) {
        HotSpotJVMCIRuntimeProvider runtime = runtime();
        HotSpotVMConfig config = runtime.getConfig();
        assert config.vmSymbolsFirstSID <= index && index < config.vmSymbolsSIDLimit : "index " + index + " is out of bounds";
        assert config.symbolPointerSize == Unsafe.ADDRESS_SIZE : "the following address read is broken";
        return runtime.getCompilerToVM().getSymbol(UNSAFE.getAddress(config.vmSymbolsSymbols + index * config.symbolPointerSize));
    }
}