git.meshlink.io Git - catta/blob - m4/gcc_visibility.m4

   1 dnl @synopsis CHECK_VISIBILITY([ACTION-IF-FOUND[, ACTION-IF-NOT-FOUND]])
   2 dnl
   3 dnl @summary check for the gcc -fvisibility flag
   4 dnl
   5
   6 AC_DEFUN([CHECK_VISIBILITY_HIDDEN], [
   7   save_CFLAGS="$CFLAGS"
   8   VISIBILITY_HIDDEN_CFLAGS=""
   9   OPTION=-fvisibility=hidden
  10
  11   AC_MSG_CHECKING(for gcc $OPTION support)
  12
  13   CFLAGS="$CFLAGS $OPTION"
  14
  15   AC_TRY_COMPILE([
  16       int default_vis __attribute__ ((visibility("default")));
  17       int hidden_vis __attribute__ ((visibility("hidden")));
  18     ],
  19     [],
  20     ac_visibility_supported=yes,
  21     ac_visibility_supported=no)
  22   AC_MSG_RESULT($ac_visibility_supported)
  23
  24   if test x"$ac_visibility_supported" = xyes; then
  25     ifelse([$1],,AC_DEFINE(HAVE_GCC_VISIBILITY,1,[Define if you have gcc -fvisibility=hidden support ]),[$1])
  26     VISIBILITY_HIDDEN_CFLAGS="$OPTION -DHAVE_VISIBILITY_HIDDEN"
  27     AC_DEFINE(HAVE_VISIBILITY_HIDDEN,[],[Support for visibility hidden])
  28   else
  29     $2
  30     :
  31   fi
  32
  33   AC_SUBST(VISIBILITY_HIDDEN_CFLAGS)
  34
  35   CFLAGS="$save_CFLAGS"
  36 ])