clutter: Assume compiler supports visibility flag and attributes

Unconditionally pass -fvisibility=hidden to compiler and define
_CLUTTER_EXTERN to __attribute__((visibility("default"))) extern.

clutter/clutter/Makefile.am

@@ -14,6 +14,7 @@ AM_CPPFLAGS = \
 	-DCLUTTER_COMPILATION=1			\
 	-DCOGL_DISABLE_DEPRECATION_WARNINGS	\
 	-DG_LOG_DOMAIN=\"Clutter\" 		\
+	-fvisibility=hidden			\
 	-I$(top_srcdir) 			\
 	-I$(top_srcdir)/clutter			\
 	-I$(top_builddir)			\
@@ -23,7 +24,6 @@ AM_CPPFLAGS = \
 	-I$(top_builddir)/../cogl/cogl		\
 	$(CLUTTER_DEPRECATED_CFLAGS)		\
 	$(CLUTTER_DEBUG_CFLAGS)			\
-	$(CLUTTER_HIDDEN_VISIBILITY_CFLAGS)	\
 	$(NULL)
 
 AM_CFLAGS = $(CLUTTER_CFLAGS) $(MAINTAINER_CFLAGS)

clutter/clutter/clutter-macros.h

@@ -90,9 +90,7 @@
 #define CLUTTER_PRIVATE_FIELD(x)        clutter_private_ ## x
 #endif
 
-#ifndef _CLUTTER_EXTERN
-#define _CLUTTER_EXTERN extern
-#endif
+#define _CLUTTER_EXTERN __attribute__((visibility("default"))) extern
 
 #if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6) || \
   __clang_major__ > 3 || (__clang_major__ == 3 && __clang_minor__ >= 4)

clutter/configure.ac

@@ -101,26 +101,6 @@ AC_ARG_ENABLE([Bsymbolic],
 AS_IF([test "x$enable_Bsymbolic" = "xyes"], [CLUTTER_LINK_FLAGS=-Wl[,]-Bsymbolic-functions])
 AC_SUBST(CLUTTER_LINK_FLAGS)
 
-# Check for the visibility flags
-CLUTTER_HIDDEN_VISIBILITY_CFLAGS=""
-dnl on other compilers, check if we can do -fvisibility=hidden
-SAVED_CFLAGS="${CFLAGS}"
-CFLAGS="-fvisibility=hidden"
-AC_MSG_CHECKING([for -fvisibility=hidden compiler flag])
-AC_TRY_COMPILE([], [return 0],
-	       AC_MSG_RESULT(yes)
-	       enable_fvisibility_hidden=yes,
-	       AC_MSG_RESULT(no)
-	       enable_fvisibility_hidden=no)
-CFLAGS="${SAVED_CFLAGS}"
-
-AS_IF([test "${enable_fvisibility_hidden}" = "yes"], [
-  AC_DEFINE([_CLUTTER_EXTERN], [__attribute__((visibility("default"))) extern],
-	    [defines how to decorate public symbols while building])
-  CLUTTER_HIDDEN_VISIBILITY_CFLAGS="-fvisibility=hidden"
-])
-AC_SUBST(CLUTTER_HIDDEN_VISIBILITY_CFLAGS)
-
 AC_CACHE_SAVE
 
 dnl ========================================================================