m4/c11.m4

   1 # Check for the presence of C11 features.
   2
   3 # Check for C11 _Static_assert
   4 #
   5 AC_DEFUN([FC_C11_STATIC_ASSERT],
   6 [
   7   AC_CACHE_CHECK([for C11 static assert], [ac_cv_c11_static_assert],
   8     [AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <assert.h>
   9 ]], [[ _Static_assert(1, "1 is not true"); ]])],
  10 [ac_cv_c11_static_assert=yes], [ac_cv_c11_static_assert=no])])
  11   if test "x${ac_cv_c11_static_assert}" = "xyes" ; then
  12     AC_DEFINE([FREECIV_C11_STATIC_ASSERT], [1], [C11 static assert supported])
  13   fi
  14 ])
  15
  16 AC_DEFUN([FC_C11_AT_QUICK_EXIT],
  17 [
  18   AC_CACHE_CHECK([for C11 at_quick_exit()], [ac_cv_c11_at_quick_exit], [
  19     dnl Add -Werror to detect cases where the header does not declare
  20     dnl at_quick_exit() but linking still work. This situation can happen
  21     dnl when the header is strict about the fact that at_quick_exit() is
  22     dnl a C11 feature and the compiler is not in C11 mode.
  23     dnl $EXTRA_DEBUG_CFLAGS contains -Wmissing-declarations if it's supported.
  24     fc_save_CPPFLAGS="$CPPFLAGS"
  25     CPPFLAGS="$CPPFLAGS -Werror $EXTRA_DEBUG_CFLAGS"
  26     AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <stdlib.h>
  27 static void func(void)
  28 {}
  29 ]], [[ at_quick_exit(func); ]])],
  30 [ac_cv_c11_at_quick_exit=yes], [ac_cv_c11_at_quick_exit=no])
  31     CPPFLAGS="$fc_save_CPPFLAGS"])
  32   if test "x${ac_cv_c11_at_quick_exit}" = "xyes" ; then
  33     AC_DEFINE([HAVE_AT_QUICK_EXIT], [1], [C11 at_quick_exit() available])
  34   fi
  35 ])