1 /*
   2  * Copyright (c) 2014, 2015, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 package jdk.vm.ci.hotspot;
  24 
  25 import static jdk.vm.ci.hotspot.HotSpotJVMCIRuntime.runtime;
  26 import static jdk.vm.ci.hotspot.UnsafeAccess.UNSAFE;
  27 import sun.misc.Unsafe;
  28 
  29 /**
  30  * Class to access the C++ {@code vmSymbols} table.
  31  */
  32 final class HotSpotVmSymbols {
  33 
  34     /**
  35      * Returns the symbol in the {@code vmSymbols} table at position {@code index} as {@link String}
  36      * .
  37      *
  38      * @param index position in the symbol table
  39      * @return the symbol at position id
  40      */
  41     static String symbolAt(int index) {
  42         HotSpotJVMCIRuntimeProvider runtime = runtime();
  43         HotSpotVMConfig config = runtime.getConfig();
  44         assert config.vmSymbolsFirstSID <= index && index < config.vmSymbolsSIDLimit : "index " + index + " is out of bounds";
  45         assert config.symbolPointerSize == Unsafe.ADDRESS_SIZE : "the following address read is broken";
  46         return runtime.getCompilerToVM().getSymbol(UNSAFE.getAddress(config.vmSymbolsSymbols + index * config.symbolPointerSize));
  47     }
  48 }