Do not export internal symbols from a unix shared library.

CMakeLists.txt

@@ -77,6 +77,9 @@ endif()
 #--------------------------------------------------------------------
 if (BUILD_SHARED_LIBS)
     set(_GLFW_BUILD_DLL 1)
+    if (UNIX OR APPLE)
+        add_definitions(-fvisibility=hidden)
+    endif()
 endif()
 
 #--------------------------------------------------------------------

include/GL/glfw3.h

@@ -157,6 +157,10 @@ extern "C" {
   #define GLFWAPI __declspec(dllimport)
  #endif
 
+#elif defined(__GNUC__) && defined(_GLFW_BUILD_DLL)
+
+ #define GLFWAPI __attribute__((visibility("default")))
+
 #else
 
  /* We are either building/calling a static lib or we are non-win32 */