m4/gcc4_visibility.m4

   1
   2 # GCC 4.x -fvisibility=hidden
   3
   4 AC_DEFUN([CHECK_GCC_FVISIBILITY], [
   5         AC_LANG_PUSH([C])
   6         saved_CFLAGS="$CFLAGS"
   7         CFLAGS="$saved_CFLAGS -fvisibility=hidden"
   8         AC_CACHE_CHECK([whether compiler accepts -fvisibility=hidden],
   9           [ac_cv_fvisibility_hidden], AC_COMPILE_IFELSE(
  10                 [AC_LANG_SOURCE()],
  11                 [ac_cv_fvisibility_hidden=yes],
  12                 [ac_cv_fvisibility_hidden=no]
  13         ))
  14         if test "$ac_cv_fvisibility_hidden" = "yes"; then
  15                 AC_DEFINE([HAVE_VISIBILITY_HIDDEN], [1],
  16                         [True if compiler supports -fvisibility=hidden])
  17                 AC_SUBST([GCC_FVISIBILITY_HIDDEN], [-fvisibility=hidden])
  18         fi
  19         CFLAGS="$saved_CFLAGS"
  20         AC_LANG_POP([C])
  21 ])