libebml: use the visibility attribute with GCC to export lib APIs

configure.ac

@@ -10,5 +10,4 @@ AC_ARG_ENABLE([debug],
 	[enable_debug="$withval"], [enable_debug=no])
 AM_CONDITIONAL([ENABLE_DEBUG], [test "$enable_debug" = yes])
 AC_CONFIG_FILES([Makefile libebml.pc])
-AC_CHECK_HEADERS([winapifamily.h])
 AC_OUTPUT

ebml/EbmlConfig.h

@@ -36,10 +36,6 @@
 #ifndef LIBEBML_CONFIG_H
 #define LIBEBML_CONFIG_H
 
-#ifdef HAVE_CONFIG_H
-#include "config.h"
-#endif
-
 #if defined(__linux__)
 #include <endian.h>
 #if __BYTE_ORDER == __LITTLE_ENDIAN
@@ -82,14 +78,22 @@
 #   define EBML_DLL_API __declspec(dllimport)
 #  endif // EBML_DLL_EXPORT
 # else // EBML_DLL
-#  define EBML_DLL_API
+#  if defined(__GNUC__) && __GNUC__ >= 4
+#   define EBML_DLL_API __attribute__((visibility("default")))
+#  else
+#   define EBML_DLL_API
+#  endif /* __GNUC__ */
 # endif // EBML_DLL
 
 # ifdef _MSC_VER
 #  pragma warning(disable:4786)  // length of internal identifiers
 # endif // _MSC_VER
 #else
-# define EBML_DLL_API
+# if defined(__GNUC__) && __GNUC__ >= 4
+#  define EBML_DLL_API __attribute__((visibility("default")))
+# else
+#  define EBML_DLL_API
+# endif /* __GNUC__ */
 #endif // WIN32 || _WIN32
 
 
@@ -104,13 +108,6 @@
 #define LIBEBML_DEBUG
 #endif
 
-#ifdef HAVE_WINAPIFAMILY_H
-# include <winapifamily.h>
-# if !WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP)
-#  undef LIBEBML_DEBUG
-# endif
-#endif
-
 // For compilers that don't define __TIMESTAMP__ (e.g. gcc 2.95, gcc 3.2)
 #ifndef __TIMESTAMP__
 #define __TIMESTAMP__ __DATE__ " " __TIME__