SFML shared libraries now use ELF visibility on Unixes with gcc >= 4

cmake/Macros.cmake

@@ -133,6 +133,14 @@ macro(sfml_add_library target)
         endif()
     endif()
 
+    # on Unix systems with gcc 4.x, we must hide public symbols by default
+    # (exported ones are explicitely marked)
+    if((LINUX OR MACOSX) AND COMPILER_GCC)
+        if(${GCC_VERSION} MATCHES "4\\..*")
+            set_target_properties(${target} PROPERTIES COMPILE_FLAGS -fvisibility=hidden)
+        endif()
+    endif()
+
     # link the target to its SFML dependencies
     if(THIS_DEPENDS)
         target_link_libraries(${target} ${THIS_DEPENDS})

include/SFML/Config.hpp

@@ -97,7 +97,9 @@
 ////////////////////////////////////////////////////////////
 // Define portable import / export macros
 ////////////////////////////////////////////////////////////
-#if defined(SFML_SYSTEM_WINDOWS) && !defined(SFML_STATIC)
+#if !defined(SFML_STATIC)
+
+    #if defined(SFML_SYSTEM_WINDOWS)
 
         #ifdef SFML_EXPORTS
 
@@ -120,9 +122,25 @@
 
         #endif
 
+    #else // Linux, FreeBSD, Mac OS X
+
+        #if __GNUC__ >= 4
+
+            // gcc 4 has special keywords for showing/hidding symbols
+            #define SFML_API __attribute__ ((visibility ("default")))
+
+        #else
+
+            // gcc < 4 has no mechanism to explicitely hide symbols, everything's exported
+            #define SFML_API
+
+        #endif
+
+    #endif
+
 #else
 
-    // Other platforms and static build don't need these export macros
+    // Static build doesn't need these export macros
     #define SFML_API
 
 #endif