add support for the GCC visibility attribute

git-svn-id: https://swig.svn.sourceforge.net/svnroot/swig/trunk/SWIG@8919 626c5289-ae23-0410-ae9c-e8d60b6d4f22

CHANGES.current

@@ -1,5 +1,32 @@
 Version 1.3.29 (In progress)
 ============================
+03/01/2006: mmatus
+	    Use the GCC visibility attribute in SWIGEXPORT.
+
+	    Now you can compile (with gcc 4.0 or later) using
+	    CFLAGS="-fvisibility=hidden".
+	    
+	    Check the difference for the 'std_containers.i' python 
+	    test case:
+ 
+            Sizes:
+
+	      3305432 _std_containers.so
+	      2383992 _std_containers.so.hidden
+
+	    Exported symbols (nm -D <file>.so | wc -l):
+
+              6146 _std_containers.so 
+              174  _std_containers.so.hidden 
+
+	    Excecution times:
+
+	      real 0m0.050s user 0m0.039s sys 0m0.005s   _std_containers.so
+              real 0m0.039s user 0m0.026s sys 0m0.007s   _std_containers.so.hidden
+
+	    Read http://gcc.gnu.org/wiki/Visibility for more details.
+
+
 02/27/2006: mutandiz
 	    [allegrocl]
 	    Add support for INPUT, OUTPUT, and INOUT typemaps.

Lib/swiglabels.swg

@@ -50,11 +50,6 @@
 # endif
 #endif
 
-#if (__GNUC__ >= 4)
-# ifndef GCC_HASCLASSVISIBILITY
-#  define GCC_HASCLASSVISIBILITY
-# endif
-#endif
 
 /* internal SWIG method */
 #ifndef SWIGINTERN
@@ -66,7 +61,13 @@
 # define SWIGINTERNINLINE SWIGINTERN SWIGINLINE
 #endif
 
-/* exporting methods for Windows DLLs */
+/* exporting methods */
+#if (__GNUC__ >= 4)
+#  ifndef GCC_HASCLASSVISIBILITY
+#    define GCC_HASCLASSVISIBILITY
+#  endif
+#endif
+
 #ifndef SWIGEXPORT
 # if defined(_WIN32) || defined(__WIN32__) || defined(__CYGWIN__)
 #   if defined(STATIC_LINKED)