libstdc++-v3/libsupc++/guard.cc

   1 // Copyright (C) 2002 Free Software Foundation, Inc.
   2 //
   3 // This file is part of GCC.
   4 //
   5 // GCC is free software; you can redistribute it and/or modify
   6 // it under the terms of the GNU General Public License as published by
   7 // the Free Software Foundation; either version 2, or (at your option)
   8 // any later version.
   9
  10 // GCC is distributed in the hope that it will be useful,
  11 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 // GNU General Public License for more details.
  14
  15 // You should have received a copy of the GNU General Public License
  16 // along with GCC; see the file COPYING.  If not, write to
  17 // the Free Software Foundation, 59 Temple Place - Suite 330,
  18 // Boston, MA 02111-1307, USA.
  19
  20 // As a special exception, you may use this file as part of a free software
  21 // library without restriction.  Specifically, if other files instantiate
  22 // templates or use macros or inline functions from this file, or you compile
  23 // this file and link it with other files to produce an executable, this
  24 // file does not by itself cause the resulting executable to be covered by
  25 // the GNU General Public License.  This exception does not however
  26 // invalidate any other reasons why the executable file might be covered by
  27 // the GNU General Public License.
  28
  29 // Written by Mark Mitchell, CodeSourcery LLC, <mark@codesourcery.com>
  30
  31 #include <cxxabi.h>
  32
  33 // The IA64/generic ABI uses the fist byte of the guard variable.
  34 // The ARM EABI uses the least significant bit.
  35
  36 namespace __cxxabiv1
  37 {
  38   extern "C"
  39   int __cxa_guard_acquire (__guard *g)
  40   {
  41 #ifdef __ARM_EABI__
  42     return !(*g & 1);
  43 #else
  44     return !*(char *)(g);
  45 #endif
  46   }
  47
  48   extern "C"
  49   void __cxa_guard_release (__guard *g)
  50   {
  51 #ifdef __ARM_EABI__
  52     *g = 1;
  53 #else
  54     *(char *)g = 1;
  55 #endif
  56   }
  57
  58   extern "C"
  59   void __cxa_guard_abort (__guard *)
  60   {
  61   }
  62 }