wrapper/compiler.h

   1 #ifndef _LTTNG_WRAPPER_COMPILER_H
   2 #define _LTTNG_WRAPPER_COMPILER_H
   3
   4 /*
   5  * wrapper/compiler.h
   6  *
   7  * Copyright (C) 2013 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   8  *
   9  * This library is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public
  11  * License as published by the Free Software Foundation; only
  12  * version 2.1 of the License.
  13  *
  14  * This library is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  17  * Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public
  20  * License along with this library; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  22  */
  23
  24 #include <linux/compiler.h>
  25
  26 /*
  27  * Don't allow compiling with buggy compiler.
  28  */
  29
  30 #ifdef GCC_VERSION
  31
  32 /*
  33  * http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58854
  34  */
  35 # ifdef __ARMEL__
  36 #  if GCC_VERSION >= 40800 && GCC_VERSION <= 40802
  37 #   error Your gcc version produces clobbered frame accesses
  38 #  endif
  39 # endif
  40 #endif
  41
  42 /*
  43  * READ/WRITE_ONCE were introduced in kernel 3.19 and ACCESS_ONCE
  44  * was removed in 4.15. Prefer READ/WRITE but fallback to ACCESS
  45  * when they are not available.
  46  */
  47 #ifndef READ_ONCE
  48 # define READ_ONCE(x)           ACCESS_ONCE(x)
  49 #endif
  50
  51 #ifndef WRITE_ONCE
  52 # define WRITE_ONCE(x, val)     ({ ACCESS_ONCE(x) = val; })
  53 #endif
  54
  55 #endif /* _LTTNG_WRAPPER_COMPILER_H */