The visibility attribute was actually added in gcc 3.3.x, not 4.0.

Just assume that if -fvisibility=hidden works that the attribute
is usable.

config.h.in

@@ -115,6 +115,9 @@
 /* Define to 1 if you have the `dlopen' function. */
 #undef HAVE_DLOPEN
 
+/* Define to 1 if the compiler supports the __visibility__ attribute. */
+#undef HAVE_DSO_VISIBILITY
+
 /* Define to 1 if your system has the F_CLOSEM fcntl. */
 #undef HAVE_FCNTL_CLOSEM
 

configure

@@ -20110,6 +20110,8 @@ eval ac_res=\$$as_CACHEVAR
 $as_echo "$ac_res" >&6; }
 if test x"`eval 'as_val=${'$as_CACHEVAR'};$as_echo "$as_val"'`" = xyes; then :
 
+    $as_echo "#define HAVE_DSO_VISIBILITY 1" >>confdefs.h
+
     CFLAGS="${CFLAGS} -fvisibility=hidden"
     LTEXP="#"
 
@@ -22740,5 +22742,6 @@ fi
 
 
 
+
 
 

configure.in

@@ -3173,6 +3173,7 @@ dnl into fatal errors (and there is no way to undo that)
 dnl
 AC_LANG_WERROR
 AX_CHECK_COMPILE_FLAG([-fvisibility=hidden], [
+    AC_DEFINE(HAVE_DSO_VISIBILITY)
     CFLAGS="${CFLAGS} -fvisibility=hidden"
     LTEXP="#"
 ])
@@ -3460,6 +3461,7 @@ AH_TEMPLATE(RTLD_PRELOAD_VAR, [The environment variable that controls preloading
 AH_TEMPLATE(RTLD_PRELOAD_ENABLE_VAR, [An extra environment variable that is required to enable preloading (if any).])
 AH_TEMPLATE(RTLD_PRELOAD_DELIM, [The delimiter to use when defining multiple preloaded objects.])
 AH_TEMPLATE(RTLD_PRELOAD_DEFAULT, [The default value of preloaded objects (if any).])
+AH_TEMPLATE(HAVE_DSO_VISIBILITY, [Define to 1 if the compiler supports the __visibility__ attribute.])
 
 dnl
 dnl Bits to copy verbatim into config.h.in

include/missing.h

@@ -53,7 +53,7 @@
 #endif
 
 #ifndef __dso_public
-# if __GNUC_PREREQ__(4, 0)
+# ifdef HAVE_DSO_VISIBILITY
 #  define __dso_public	__attribute__((__visibility__("default")))
 #  define __dso_hidden	__attribute__((__visibility__("hidden")))
 # else