libgcc/config/gthr-lynx.h

   1 /* Threads compatibility routines for libgcc2 and libobjc for
   2    LynxOS.  */
   3 /* Compile this one with gcc.  */
   4 /* Copyright (C) 2004-2017 Free Software Foundation, Inc.
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify it under
   9 the terms of the GNU General Public License as published by the Free
  10 Software Foundation; either version 3, or (at your option) any later
  11 version.
  12
  13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  16 for more details.
  17
  18 Under Section 7 of GPL version 3, you are granted additional
  19 permissions described in the GCC Runtime Library Exception, version
  20 3.1, as published by the Free Software Foundation.
  21
  22 You should have received a copy of the GNU General Public License and
  23 a copy of the GCC Runtime Library Exception along with this program;
  24 see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  25 <http://www.gnu.org/licenses/>.  */
  26
  27 #ifndef GCC_GTHR_LYNX_H
  28 #define GCC_GTHR_LYNX_H
  29
  30 #ifdef _MULTITHREADED
  31
  32 /* Using the macro version of pthread_setspecific leads to a
  33    compilation error.  Instead we have two choices either kill all
  34    macros in pthread.h with defining _POSIX_THREADS_CALLS or undefine
  35    individual macros where we should fall back on the function
  36    implementation.  We choose the second approach.  */
  37
  38 #include <pthread.h>
  39 #undef pthread_setspecific
  40
  41 /* When using static libc on LynxOS, we cannot define pthread_create
  42    weak.  If the multi-threaded application includes iostream.h,
  43    gthr-posix.h is included and pthread_create will be defined weak.
  44    If pthread_create is weak its defining module in libc is not
  45    necessarily included in the link and the symbol is resolved to zero.
  46    Therefore the first call to it will crash.
  47
  48    Since -mthreads is a multilib switch on LynxOS we know that at this
  49    point we are compiling for multi-threaded.  Omitting the weak
  50    definitions at this point should have no effect.  */
  51
  52 #undef  GTHREAD_USE_WEAK
  53 #define GTHREAD_USE_WEAK 0
  54
  55 #include "gthr-posix.h"
  56
  57 #else
  58 #include "gthr-single.h"
  59 #endif
  60
  61 #endif /* GCC_GTHR_LYNX_H */