--- /dev/null
+dnl @synopsis CHECK_VISIBILITY([ACTION-IF-FOUND[, ACTION-IF-NOT-FOUND]])
+dnl
+dnl @summary check for the gcc -fvisibility flag
+dnl
+
+AC_DEFUN([CHECK_VISIBILITY_HIDDEN], [
+ save_CFLAGS="$CFLAGS"
+ VISIBILITY_HIDDEN_CFLAGS=""
+ OPTION=-fvisibility=hidden
+
+ AC_MSG_CHECKING(for gcc $OPTION support)
+
+ CFLAGS="$CFLAGS $OPTION"
+
+ AC_TRY_COMPILE([
+ int default_vis __attribute__ ((visibility("default")));
+ int hidden_vis __attribute__ ((visibility("hidden")));
+ ],
+ [],
+ ac_visibility_supported=yes,
+ ac_visibility_supported=no)
+ AC_MSG_RESULT($ac_visibility_supported)
+
+ if test x"$ac_visibility_supported" = xyes; then
+ ifelse([$1],,AC_DEFINE(HAVE_GCC_VISIBILITY,1,[Define if you have gcc -fvisibility=hidden support ]),[$1])
+ VISIBILITY_HIDDEN_CFLAGS="$OPTION -DHAVE_VISIBILITY_HIDDEN"
+ AC_DEFINE(HAVE_VISIBILITY_HIDDEN,[],[Support for visibility hidden])
+ else
+ $2
+ :
+ fi
+
+ AC_SUBST(VISIBILITY_HIDDEN_CFLAGS)
+
+ CFLAGS="$save_CFLAGS"
+])