libs: fix API export/import and 'inconsistent linkage' on MSVC

For each lib we build export its own API in headers when we're
building it, otherwise import the API from the headers.

This fixes linker warnings on Windows when building with MSVC.

The problem was that we had defined all GST_*_API decorators
unconditionally to GST_EXPORT. This was intentional and only
supposed to be temporary, but caused linker warnings because
we tell the linker that we want to export all symbols even
those from externall DLLs, and when the linker notices that
they were in external DLLS and not present locally it warns.

What we need to do when building each library is: export
the library's own symbols and import all other symbols. To
this end we define e.g. BUILDING_GST_FOO and then we define
the GST_FOO_API decorator either to export or to import
symbols depending on whether BUILDING_GST_FOO is set or not.
That way external users of each library API automatically
get the import.

While we're at it, add new GST_API_EXPORT in config.h and use
that for GST_*_API decorators instead of GST_EXPORT.

The right export define depends on the toolchain and whether
we're using -fvisibility=hidden or not, so it's better to set it
to the right thing directly than hard-coding a compiler whitelist
in the public header.

We put the export define into config.h instead of passing it via the
command line to the compiler because it might contain spaces and brackets
and in the autotools scenario we'd have to pass that through multiple
layers of plumbing and Makefile/shell escaping and we're just not going
to be *that* lucky.

The export define is only used if we're compiling our lib, not by external
users of the lib headers, so it's not a problem to put it into config.h

Also, this means all .c files of libs need to include config.h
to get the export marker defined, so fix up a few that didn't
include config.h.

This commit depends on a common submodule commit that makes gst-glib-gen.mak
add an #include "config.h" to generated enum/marshal .c files for the
autotools build.

https://bugzilla.gnome.org/show_bug.cgi?id=797185

configure.ac

@@ -841,7 +841,13 @@ fi
 AC_SUBST(DEPRECATED_CFLAGS)
 
 VISIBILITY_CFLAGS=""
-AS_COMPILER_FLAG([-fvisibility=hidden], [VISIBILITY_CFLAGS="-fvisibility=hidden"])
+AS_COMPILER_FLAG([-fvisibility=hidden], [
+  VISIBILITY_CFLAGS="-fvisibility=hidden"
+  AC_DEFINE(GST_API_EXPORT, [extern __attribute__ ((visibility ("default")))], [public symbol export define])
+], [
+  VISIBILITY_CFLAGS=""
+  AC_DEFINE(GST_API_EXPORT, [extern], [public symbol export define])
+])
 AC_SUBST(VISIBILITY_CFLAGS)
 
 VISIBILITY_CXXFLAGS=""

gst-libs/gst/allocators/Makefile.am

@@ -17,7 +17,7 @@ libgstallocators_@GST_API_VERSION@_la_SOURCES = \
 	gstdmabuf.c 
 
 libgstallocators_@GST_API_VERSION@_la_LIBADD = $(GST_LIBS) $(LIBM)
-libgstallocators_@GST_API_VERSION@_la_CFLAGS = $(GST_PLUGINS_BASE_CFLAGS) $(GST_CFLAGS)
+libgstallocators_@GST_API_VERSION@_la_CFLAGS = $(GST_PLUGINS_BASE_CFLAGS) $(GST_CFLAGS) -DBUILDING_GST_ALLOCATORS
 libgstallocators_@GST_API_VERSION@_la_LDFLAGS = $(GST_LIB_LDFLAGS) $(GST_ALL_LDFLAGS) $(GST_LT_LDFLAGS)
 
 if HAVE_INTROSPECTION

gst-libs/gst/allocators/allocators-prelude.h

@@ -24,8 +24,10 @@
 
 #include <gst/gst.h>
 
-#ifndef GST_ALLOCATORS_API
-#define GST_ALLOCATORS_API GST_EXPORT
+#ifdef BUILDING_GST_ALLOCATORS
+#define GST_ALLOCATORS_API GST_API_EXPORT         /* from config.h */
+#else
+#define GST_ALLOCATORS_API GST_API_IMPORT
 #endif
 
 #endif /* __GST_ALLOCATORS_PRELUDE_H__ */

gst-libs/gst/allocators/meson.build

@@ -10,7 +10,7 @@ install_headers(gst_allocators_headers, subdir : 'gstreamer-1.0/gst/allocators/'
 gst_allocators_sources = [ 'gstdmabuf.c', 'gstfdmemory.c', 'gstphysmemory.c']
 gstallocators = library('gstallocators-@0@'.format(api_version),
   gst_allocators_sources,
-  c_args : gst_plugins_base_args,
+  c_args : gst_plugins_base_args + ['-DBUILDING_GST_ALLOCATORS'],
   include_directories: [configinc, libsinc],
   version : libversion,
   soversion : soversion,

gst-libs/gst/app/Makefile.am

@@ -17,7 +17,7 @@ include $(top_srcdir)/common/gst-glib-gen.mak
 libgstapp_@GST_API_VERSION@_la_SOURCES = gstappsrc.c gstappsink.c
 nodist_libgstapp_@GST_API_VERSION@_la_SOURCES = $(BUILT_SOURCES)
 libgstapp_@GST_API_VERSION@_la_CFLAGS = $(GST_PLUGINS_BASE_CFLAGS) \
-	$(GST_BASE_CFLAGS) $(GST_CFLAGS)
+	$(GST_BASE_CFLAGS) $(GST_CFLAGS) -DBUILDING_GST_APP
 libgstapp_@GST_API_VERSION@_la_LIBADD = $(GST_BASE_LIBS)
 libgstapp_@GST_API_VERSION@_la_LDFLAGS = $(GST_LIB_LDFLAGS) $(GST_ALL_LDFLAGS) $(GST_LT_LDFLAGS)
 

gst-libs/gst/app/app-prelude.h

@@ -24,8 +24,10 @@
 
 #include <gst/gst.h>
 
-#ifndef GST_APP_API
-#define GST_APP_API GST_EXPORT
+#ifdef BUILDING_GST_APP
+#define GST_APP_API GST_API_EXPORT         /* from config.h */
+#else
+#define GST_APP_API GST_API_IMPORT
 #endif
 
 #endif /* __GST_APP_PRELUDE_H__ */

gst-libs/gst/app/meson.build

@@ -9,6 +9,7 @@ install_headers(app_headers, subdir : 'gstreamer-1.0/gst/app/')
 
 app_enums = gnome.mkenums_simple('app-enumtypes',
   sources : app_mkenum_headers,
+  body_prefix : '#ifdef HAVE_CONFIG_H\n#include "config.h"\n#endif',
   header_prefix : '#include <gst/app/app-prelude.h>',
   decorator : 'GST_APP_API',
   install_header: true,
@@ -20,7 +21,7 @@ app_gen_sources = [gstapp_h]
 
 gstapp = library('gstapp-@0@'.format(api_version),
   app_sources, gstapp_h, gstapp_c,
-  c_args : gst_plugins_base_args,
+  c_args : gst_plugins_base_args + ['-DBUILDING_GST_APP'],
   include_directories: [configinc, libsinc],
   version : libversion,
   soversion : soversion,

gst-libs/gst/audio/Makefile.am

@@ -104,7 +104,7 @@ noinst_HEADERS = \
 	audio-resampler-neon.h
 
 libgstaudio_@GST_API_VERSION@_la_CFLAGS = $(GST_PLUGINS_BASE_CFLAGS) $(GST_BASE_CFLAGS) $(GST_CFLAGS) \
-		$(ORC_CFLAGS)
+		$(ORC_CFLAGS) -DBUILDING_GST_AUDIO
 libgstaudio_@GST_API_VERSION@_la_LIBADD = \
   $(top_builddir)/gst-libs/gst/tag/libgsttag-@GST_API_VERSION@.la \
   $(GST_BASE_LIBS) $(GST_LIBS) $(LIBM) $(ORC_LIBS)

gst-libs/gst/audio/audio-prelude.h

@@ -24,8 +24,10 @@
 
 #include <gst/gst.h>
 
-#ifndef GST_AUDIO_API
-#define GST_AUDIO_API GST_EXPORT
+#ifdef BUILDING_GST_AUDIO
+#define GST_AUDIO_API GST_API_EXPORT         /* from config.h */
+#else
+#define GST_AUDIO_API GST_API_IMPORT
 #endif
 
 #endif /* __GST_AUDIO_PRELUDE_H__ */

gst-libs/gst/audio/meson.build

@@ -64,6 +64,7 @@ install_headers(audio_headers, subdir : 'gstreamer-1.0/gst/audio/')
 
 audio_enums = gnome.mkenums_simple('audio-enumtypes',
   sources : audio_mkenum_headers,
+  body_prefix : '#ifdef HAVE_CONFIG_H\n#include "config.h"\n#endif',
   header_prefix : '#include <gst/audio/audio-prelude.h>',
   decorator : 'GST_AUDIO_API',
   install_header: true,
@@ -140,7 +141,7 @@ endif
 
 gstaudio = library('gstaudio-@0@'.format(api_version),
   audio_src, gstaudio_h, gstaudio_c, orc_c, orc_h,
-  c_args : gst_plugins_base_args + simd_cargs,
+  c_args : gst_plugins_base_args + simd_cargs + ['-DBUILDING_GST_AUDIO'],
   include_directories: [configinc, libsinc],
   link_with : simd_dependencies,
   version : libversion,

gst-libs/gst/fft/Makefile.am

@@ -41,7 +41,7 @@ libgstfft_@GST_API_VERSION@_la_SOURCES = \
 	kiss_fftr_f64.c
 
 libgstfft_@GST_API_VERSION@_la_LIBADD = $(GST_LIBS) $(LIBM)
-libgstfft_@GST_API_VERSION@_la_CFLAGS =  $(GST_PLUGINS_BASE_CFLAGS) $(GST_CFLAGS)
+libgstfft_@GST_API_VERSION@_la_CFLAGS =  $(GST_PLUGINS_BASE_CFLAGS) $(GST_CFLAGS) -DBUILDING_GST_FFT
 libgstfft_@GST_API_VERSION@_la_LDFLAGS = $(GST_LIB_LDFLAGS) $(GST_ALL_LDFLAGS) $(GST_LT_LDFLAGS)
 
 EXTRA_DIST = kiss_version

gst-libs/gst/fft/fft-prelude.h

@@ -24,8 +24,10 @@
 
 #include <gst/gst.h>
 
-#ifndef GST_FFT_API
-#define GST_FFT_API GST_EXPORT
+#ifdef BUILDING_GST_FFT
+#define GST_FFT_API GST_API_EXPORT         /* from config.h */
+#else
+#define GST_FFT_API GST_API_IMPORT
 #endif
 
 #endif /* __GST_FFT_PRELUDE_H__ */

gst-libs/gst/fft/meson.build

@@ -27,7 +27,7 @@ install_headers(fft_headers, subdir : 'gstreamer-1.0/gst/fft/')
 
 gstfft = library('gstfft-@0@'.format(api_version),
   fft_sources,
-  c_args : gst_plugins_base_args,
+  c_args : gst_plugins_base_args + ['-DBUILDING_GST_FFT'],
   include_directories: [configinc, libsinc],
   version : libversion,
   soversion : soversion,

gst-libs/gst/gl/Makefile.am

@@ -155,7 +155,7 @@ configexecincludedir = $(libdir)/gstreamer-@GST_API_VERSION@/include/gst/gl
 nodist_configexecinclude_HEADERS = $(built_sys_header_configure)
 
 libgstgl_@GST_API_VERSION@_la_CFLAGS = \
-	-DGST_EXPORTS \
+	-DBUILDING_GST_GL \
 	$(GST_PLUGINS_BASE_CFLAGS) \
 	$(GST_BASE_CFLAGS) \
 	$(GST_CFLAGS) \

gst-libs/gst/gl/android/Makefile.am

@@ -11,6 +11,7 @@ noinst_HEADERS = \
 libgstgl_android_la_CFLAGS = \
 	-I$(top_srcdir)/gst-libs \
 	-I$(top_builddir)/gst-libs \
+	-DBUILDING_GST_GL \
 	$(GL_CFLAGS) \
 	$(GST_PLUGINS_BASE_CFLAGS) \
 	$(GST_BASE_CFLAGS) \

gst-libs/gst/gl/cocoa/Makefile.am

@@ -21,6 +21,7 @@ libgstgl_cocoainclude_HEADERS = \
 libgstgl_cocoa_la_CFLAGS = \
 	-I$(top_srcdir)/gst-libs \
 	-I$(top_builddir)/gst-libs \
+	-DBUILDING_GST_GL \
 	$(GL_CFLAGS) \
 	$(GST_PLUGINS_BASE_CFLAGS) \
 	$(GST_BASE_CFLAGS) \

gst-libs/gst/gl/dispmanx/Makefile.am

@@ -11,6 +11,7 @@ noinst_HEADERS = \
 libgstgl_dispmanx_la_CFLAGS = \
 	-I$(top_srcdir)/gst-libs \
 	-I$(top_builddir)/gst-libs \
+	-DBUILDING_GST_GL \
 	$(GL_CFLAGS) \
 	$(GST_PLUGINS_BASE_CFLAGS) \
 	$(GST_BASE_CFLAGS) \

gst-libs/gst/gl/eagl/Makefile.am

@@ -13,6 +13,7 @@ noinst_HEADERS = \
 libgstgl_eagl_la_CFLAGS = \
 	-I$(top_srcdir)/gst-libs \
 	-I$(top_builddir)/gst-libs \
+	-DBUILDING_GST_GL \
 	$(GL_CFLAGS) \
 	$(GST_PLUGINS_BASE_CFLAGS) \
 	$(GST_BASE_CFLAGS) \

gst-libs/gst/gl/egl/Makefile.am

@@ -22,6 +22,7 @@ libgstgl_eglinclude_HEADERS = \
 libgstgl_egl_la_CFLAGS = \
 	-I$(top_srcdir)/gst-libs \
 	-I$(top_builddir)/gst-libs \
+	-DBUILDING_GST_GL \
 	$(GL_CFLAGS) \
 	$(GST_PLUGINS_BASE_CFLAGS) \
 	$(GST_BASE_CFLAGS) \

gst-libs/gst/gl/gbm/Makefile.am

@@ -15,6 +15,7 @@ noinst_HEADERS = \
 libgstgl_gbm_la_CFLAGS = \
 	-I$(top_srcdir)/gst-libs \
 	-I$(top_builddir)/gst-libs \
+	-DBUILDING_GST_GL \
 	$(GL_CFLAGS) \
 	$(GST_PLUGINS_BASE_CFLAGS) \
 	$(GST_BASE_CFLAGS) \

gst-libs/gst/gl/gl-prelude.h

@@ -24,8 +24,10 @@
 
 #include <gst/gst.h>
 
-#ifndef GST_GL_API
-#define GST_GL_API GST_EXPORT
+#ifdef BUILDING_GST_GL
+#define GST_GL_API GST_API_EXPORT         /* from config.h */
+#else
+#define GST_GL_API GST_API_IMPORT
 #endif
 
 #endif /* __GST_GL_PRELUDE_H__ */

gst-libs/gst/gl/meson.build

@@ -877,8 +877,8 @@ if build_gstgl
 
   gstgl = library('gstgl-' + api_version,
     gl_sources,
-    c_args : gst_plugins_base_args + gl_cpp_args,
-    objc_args : gst_plugins_base_args + gl_cpp_args + gl_objc_args,
+    c_args : gst_plugins_base_args + gl_cpp_args + ['-DBUILDING_GST_GL'],
+    objc_args : gst_plugins_base_args + gl_cpp_args + gl_objc_args + ['-DBUILDING_GST_GL'],
     include_directories : [configinc, libsinc, gl_includes],
     version : libversion,
     soversion : soversion,

gst-libs/gst/gl/viv-fb/Makefile.am

@@ -17,6 +17,7 @@ libgstgl_viv_fbinclude_HEADERS = \
 libgstgl_viv_fb_la_CFLAGS = \
 	-I$(top_srcdir)/gst-libs \
 	-I$(top_builddir)/gst-libs \
+	-DBUILDING_GST_GL \
 	$(GL_CFLAGS) \
 	$(GST_PLUGINS_BASE_CFLAGS) \
 	$(GST_BASE_CFLAGS) \

gst-libs/gst/gl/wayland/Makefile.am

@@ -18,6 +18,7 @@ libgstgl_waylandinclude_HEADERS = \
 libgstgl_wayland_la_CFLAGS = \
 	-I$(top_srcdir)/gst-libs \
 	-I$(top_builddir)/gst-libs \
+	-DBUILDING_GST_GL \
 	$(GL_CFLAGS) \
 	$(GST_PLUGINS_BASE_CFLAGS) \
 	$(GST_BASE_CFLAGS) \

gst-libs/gst/gl/win32/Makefile.am

@@ -14,9 +14,9 @@ noinst_HEADERS += gstglcontext_wgl.h
 endif
 
 libgstgl_win32_la_CFLAGS = \
-	-DGST_EXPORTS \
 	-I$(top_srcdir)/gst-libs \
 	-I$(top_builddir)/gst-libs \
+	-DBUILDING_GST_GL \
 	$(GL_CFLAGS) \
 	$(GST_PLUGINS_BASE_CFLAGS) \
 	$(GST_BASE_CFLAGS) \

gst-libs/gst/gl/x11/Makefile.am

@@ -23,6 +23,7 @@ endif
 libgstgl_x11_la_CFLAGS = \
 	-I$(top_srcdir)/gst-libs \
 	-I$(top_builddir)/gst-libs \
+	-DBUILDING_GST_GL \
 	$(GL_CFLAGS) \
 	$(GST_PLUGINS_BASE_CFLAGS) \
 	$(GST_BASE_CFLAGS) \

gst-libs/gst/pbutils/Makefile.am

@@ -54,7 +54,7 @@ libgstpbutils_@GST_API_VERSION@_la_LIBADD = \
   $(top_builddir)/gst-libs/gst/tag/libgsttag-@GST_API_VERSION@.la \
   $(GST_BASE_LIBS) \
   $(GST_LIBS)
-libgstpbutils_@GST_API_VERSION@_la_CFLAGS = $(GST_PLUGINS_BASE_CFLAGS) $(GST_BASE_CFLAGS) $(GST_CFLAGS)
+libgstpbutils_@GST_API_VERSION@_la_CFLAGS = $(GST_PLUGINS_BASE_CFLAGS) $(GST_BASE_CFLAGS) $(GST_CFLAGS) -DBUILDING_GST_PBUTILS
 libgstpbutils_@GST_API_VERSION@_la_LDFLAGS = $(GST_LIB_LDFLAGS) $(GST_ALL_LDFLAGS) $(GST_LT_LDFLAGS)
 
 BUILT_SOURCES = \

gst-libs/gst/pbutils/meson.build

@@ -40,6 +40,7 @@ pbutils_mkenum_headers = pbutils_headers
 
 pbutils_enums = gnome.mkenums_simple('pbutils-enumtypes',
   sources : pbutils_mkenum_headers,
+  body_prefix : '#ifdef HAVE_CONFIG_H\n#include "config.h"\n#endif',
   header_prefix : '#include <gst/pbutils/pbutils-prelude.h>',
   decorator : 'GST_PBUTILS_API',
   install_header: true,
@@ -50,7 +51,7 @@ gstpbutils_h = pbutils_enums[1]
 gstpbutils_deps = [video_dep, audio_dep, tag_dep]
 pbutils = library('gstpbutils-@0@'.format(api_version),
   pbutils_sources, gstpbutils_c, gstpbutils_h,
-  c_args : gst_plugins_base_args,
+  c_args : gst_plugins_base_args + ['-DBUILDING_GST_PBUTILS'],
   include_directories: [configinc, libsinc],
   version : libversion,
   soversion : soversion,

gst-libs/gst/pbutils/pbutils-prelude.h

@@ -24,8 +24,10 @@
 
 #include <gst/gst.h>
 
-#ifndef GST_PBUTILS_API
-#define GST_PBUTILS_API GST_EXPORT
+#ifdef BUILDING_GST_PBUTILS
+#define GST_PBUTILS_API GST_API_EXPORT         /* from config.h */
+#else
+#define GST_PBUTILS_API GST_API_IMPORT
 #endif
 
 #ifndef GST_DISABLE_DEPRECATED

gst-libs/gst/riff/Makefile.am

@@ -18,7 +18,7 @@ libgstriff_@GST_API_VERSION@_la_LIBADD = \
   $(top_builddir)/gst-libs/gst/tag/libgsttag-@GST_API_VERSION@.la \
   $(GST_BASE_LIBS) $(GST_LIBS)
 
-libgstriff_@GST_API_VERSION@_la_CFLAGS = $(GST_PLUGINS_BASE_CFLAGS) $(GST_BASE_CFLAGS) $(GST_CFLAGS)
+libgstriff_@GST_API_VERSION@_la_CFLAGS = $(GST_PLUGINS_BASE_CFLAGS) $(GST_BASE_CFLAGS) $(GST_CFLAGS) -DBUILDING_GST_RIFF
 libgstriff_@GST_API_VERSION@_la_LDFLAGS = $(GST_LIB_LDFLAGS) $(GST_ALL_LDFLAGS) $(GST_LT_LDFLAGS)
 
 # *** GIR DISABLED for this library ***

gst-libs/gst/riff/meson.build

@@ -16,7 +16,7 @@ install_headers(riff_headers, subdir : 'gstreamer-1.0/gst/riff/')
 riff_deps = [audio_dep, tag_dep]
 gstriff = library('gstriff-@0@'.format(api_version),
   riff_sources,
-  c_args : gst_plugins_base_args,
+  c_args : gst_plugins_base_args + ['-DBUILDING_GST_RIFF'],
   include_directories: [configinc, libsinc],
   version : libversion,
   soversion : soversion,

gst-libs/gst/riff/riff-prelude.h

@@ -24,8 +24,10 @@
 
 #include <gst/gst.h>
 
-#ifndef GST_RIFF_API
-#define GST_RIFF_API GST_EXPORT
+#ifdef BUILDING_GST_RIFF
+#define GST_RIFF_API GST_API_EXPORT         /* from config.h */
+#else
+#define GST_RIFF_API GST_API_IMPORT
 #endif
 
 #endif /* __GST_RIFF_PRELUDE_H__ */

gst-libs/gst/rtp/Makefile.am

@@ -25,7 +25,7 @@ libgstrtp_@GST_API_VERSION@_la_SOURCES = gstrtpbuffer.c \
 built_sources = gstrtp-enumtypes.c
 built_headers = gstrtp-enumtypes.h
 
-libgstrtp_@GST_API_VERSION@_la_CFLAGS = $(GST_PLUGINS_BASE_CFLAGS) $(GST_BASE_CFLAGS) $(GST_CFLAGS)
+libgstrtp_@GST_API_VERSION@_la_CFLAGS = $(GST_PLUGINS_BASE_CFLAGS) $(GST_BASE_CFLAGS) $(GST_CFLAGS) -DBUILDING_GST_RTP
 libgstrtp_@GST_API_VERSION@_la_LIBADD = $(GST_BASE_LIBS) $(GST_LIBS)
 libgstrtp_@GST_API_VERSION@_la_LDFLAGS = $(GST_LIB_LDFLAGS) $(GST_ALL_LDFLAGS) $(GST_LT_LDFLAGS)
 

gst-libs/gst/rtp/meson.build

@@ -24,6 +24,7 @@ install_headers(rtp_headers, subdir : 'gstreamer-1.0/gst/rtp/')
 
 rtp_enums = gnome.mkenums_simple('gstrtp-enumtypes',
   sources : rtp_headers,
+  body_prefix : '#ifdef HAVE_CONFIG_H\n#include "config.h"\n#endif',
   header_prefix : '#include <gst/rtp/rtp-prelude.h>',
   decorator : 'GST_RTP_API',
   install_header: true,
@@ -34,7 +35,7 @@ gstrtp_enum_h = rtp_enums[1]
 gstrtp_deps = [audio_dep, gst_base_dep]
 gst_rtp = library('gstrtp-@0@'.format(api_version),
   rtp_sources, gstrtp_enum_c, gstrtp_enum_h,
-  c_args : gst_plugins_base_args,
+  c_args : gst_plugins_base_args + ['-DBUILDING_GST_RTP'],
   include_directories: [configinc, libsinc],
   version : libversion,
   soversion : soversion,

gst-libs/gst/rtp/rtp-prelude.h

@@ -24,8 +24,10 @@
 
 #include <gst/gst.h>
 
-#ifndef GST_RTP_API
-#define GST_RTP_API GST_EXPORT
+#ifdef BUILDING_GST_RTP
+#define GST_RTP_API GST_API_EXPORT         /* from config.h */
+#else
+#define GST_RTP_API GST_API_IMPORT
 #endif
 
 #endif /* __GST_RTP_PRELUDE_H__ */

gst-libs/gst/rtsp/Makefile.am

@@ -34,7 +34,7 @@ nodist_libgstrtspinclude_HEADERS = gstrtsp-enumtypes.h
 #gstrtspextwms.c  
 #rtspextreal.c    
 
-libgstrtsp_@GST_API_VERSION@_la_CFLAGS = $(GST_PLUGINS_BASE_CFLAGS) $(GST_BASE_CFLAGS) $(GST_CFLAGS) $(GIO_CFLAGS)
+libgstrtsp_@GST_API_VERSION@_la_CFLAGS = $(GST_PLUGINS_BASE_CFLAGS) $(GST_BASE_CFLAGS) $(GST_CFLAGS) $(GIO_CFLAGS) -DBUILDING_GST_RTSP
 libgstrtsp_@GST_API_VERSION@_la_LIBADD = $(GST_BASE_LIBS) $(GST_LIBS) $(GIO_LIBS) $(LIBM)
 libgstrtsp_@GST_API_VERSION@_la_LDFLAGS = $(GST_LIB_LDFLAGS) $(GST_ALL_LDFLAGS) $(GST_LT_LDFLAGS) $(WIN32_LIBS)