wayland/eglstream: Don't build skeleton when disabled

Instead of calling no-op functions when EGLStream support isn't enabled,
make it clear at the call site that EGLStream support is optional.

src/Makefile.am

@@ -408,8 +408,6 @@ libmutter_@LIBMUTTER_API_VERSION@_la_SOURCES +=	\
 	wayland/meta-wayland-data-device.c      \
 	wayland/meta-wayland-data-device.h      \
 	wayland/meta-wayland-data-device-private.h	\
-	wayland/meta-wayland-egl-stream.c	\
-	wayland/meta-wayland-egl-stream.h	\
 	wayland/meta-wayland-input-device.c	\
 	wayland/meta-wayland-input-device.h	\
 	wayland/meta-wayland-pointer-gestures.c	\
@@ -491,6 +489,13 @@ libmutter_@LIBMUTTER_API_VERSION@_la_SOURCES +=	\
 	wayland/meta-xwayland-grab-keyboard.c  	\
 	wayland/meta-xwayland-grab-keyboard.h  	\
 	$(NULL)
+
+if HAVE_WAYLAND_EGLSTREAM
+libmutter_@LIBMUTTER_API_VERSION@_la_SOURCES +=	\
+	wayland/meta-wayland-egl-stream.c	\
+	wayland/meta-wayland-egl-stream.h	\
+	$(NULL)
+endif
 endif
 
 if HAVE_NATIVE_BACKEND

src/wayland/meta-wayland-buffer.c

@@ -108,7 +108,9 @@ meta_wayland_buffer_realize (MetaWaylandBuffer *buffer)
   ClutterBackend *clutter_backend = meta_backend_get_clutter_backend (backend);
   CoglContext *cogl_context = clutter_backend_get_cogl_context (clutter_backend);
   EGLDisplay egl_display = cogl_egl_context_get_egl_display (cogl_context);
+#ifdef HAVE_WAYLAND_EGLSTREAM
   MetaWaylandEglStream *stream;
+#endif
   MetaWaylandDmaBufBuffer *dma_buf;
 
   if (wl_shm_buffer_get (buffer->resource) != NULL)
@@ -125,6 +127,7 @@ meta_wayland_buffer_realize (MetaWaylandBuffer *buffer)
       return TRUE;
     }
 
+#ifdef HAVE_WAYLAND_EGLSTREAM
   stream = meta_wayland_egl_stream_new (buffer, NULL);
   if (stream)
     {
@@ -141,6 +144,7 @@ meta_wayland_buffer_realize (MetaWaylandBuffer *buffer)
 
       return TRUE;
     }
+#endif /* HAVE_WAYLAND_EGLSTREAM */
 
   dma_buf = meta_wayland_dma_buf_from_buffer (buffer);
   if (dma_buf)
@@ -320,6 +324,7 @@ egl_image_buffer_attach (MetaWaylandBuffer *buffer,
   return TRUE;
 }
 
+#ifdef HAVE_WAYLAND_EGLSTREAM
 static gboolean
 egl_stream_buffer_attach (MetaWaylandBuffer  *buffer,
                           GError            **error)
@@ -333,6 +338,7 @@ egl_stream_buffer_attach (MetaWaylandBuffer  *buffer,
 
   return TRUE;
 }
+#endif /* HAVE_WAYLAND_EGLSTREAM */
 
 gboolean
 meta_wayland_buffer_attach (MetaWaylandBuffer *buffer,
@@ -355,8 +361,10 @@ meta_wayland_buffer_attach (MetaWaylandBuffer *buffer,
       return shm_buffer_attach (buffer, error);
     case META_WAYLAND_BUFFER_TYPE_EGL_IMAGE:
       return egl_image_buffer_attach (buffer, error);
+#ifdef HAVE_WAYLAND_EGLSTREAM
     case META_WAYLAND_BUFFER_TYPE_EGL_STREAM:
       return egl_stream_buffer_attach (buffer, error);
+#endif
     case META_WAYLAND_BUFFER_TYPE_DMA_BUF:
       return meta_wayland_dma_buf_buffer_attach (buffer, error);
     case META_WAYLAND_BUFFER_TYPE_UNKNOWN:
@@ -376,10 +384,14 @@ meta_wayland_buffer_get_texture (MetaWaylandBuffer *buffer)
 CoglSnippet *
 meta_wayland_buffer_create_snippet (MetaWaylandBuffer *buffer)
 {
+#ifdef HAVE_WAYLAND_EGLSTREAM
   if (!buffer->egl_stream.stream)
     return NULL;
 
   return meta_wayland_egl_stream_create_snippet ();
+#else
+  return NULL;
+#endif /* HAVE_WAYLAND_EGLSTREAM */
 }
 
 gboolean
@@ -448,7 +460,9 @@ meta_wayland_buffer_process_damage (MetaWaylandBuffer *buffer,
       res = process_shm_buffer_damage (buffer, region, &error);
       break;
     case META_WAYLAND_BUFFER_TYPE_EGL_IMAGE:
+#ifdef HAVE_WAYLAND_EGLSTREAM
     case META_WAYLAND_BUFFER_TYPE_EGL_STREAM:
+#endif
     case META_WAYLAND_BUFFER_TYPE_DMA_BUF:
       res = TRUE;
       break;
@@ -473,7 +487,9 @@ meta_wayland_buffer_finalize (GObject *object)
   MetaWaylandBuffer *buffer = META_WAYLAND_BUFFER (object);
 
   g_clear_pointer (&buffer->texture, cogl_object_unref);
+#ifdef HAVE_WAYLAND_EGLSTREAM
   g_clear_object (&buffer->egl_stream.stream);
+#endif
   g_clear_object (&buffer->dma_buf.dma_buf);
 
   G_OBJECT_CLASS (meta_wayland_buffer_parent_class)->finalize (object);

src/wayland/meta-wayland-buffer.h

@@ -38,7 +38,9 @@ typedef enum _MetaWaylandBufferType
   META_WAYLAND_BUFFER_TYPE_UNKNOWN,
   META_WAYLAND_BUFFER_TYPE_SHM,
   META_WAYLAND_BUFFER_TYPE_EGL_IMAGE,
+#ifdef HAVE_WAYLAND_EGLSTREAM
   META_WAYLAND_BUFFER_TYPE_EGL_STREAM,
+#endif
   META_WAYLAND_BUFFER_TYPE_DMA_BUF,
 } MetaWaylandBufferType;
 
@@ -54,9 +56,11 @@ struct _MetaWaylandBuffer
 
   MetaWaylandBufferType type;
 
+#ifdef HAVE_WAYLAND_EGLSTREAM
   struct {
     MetaWaylandEglStream *stream;
   } egl_stream;
+#endif
 
   struct {
     MetaWaylandDmaBufBuffer *dma_buf;

src/wayland/meta-wayland-egl-stream.c

@@ -26,6 +26,8 @@
 
 #include "wayland/meta-wayland-egl-stream.h"
 
+#include <dlfcn.h>
+
 #include "backends/meta-backend-private.h"
 #include "backends/meta-egl-ext.h"
 #include "backends/meta-egl.h"
@@ -34,10 +36,6 @@
 #include "wayland/meta-wayland-buffer.h"
 #include "wayland/meta-wayland-private.h"
 
-#ifdef HAVE_WAYLAND_EGLSTREAM
-
-#include <dlfcn.h>
-
 #include "wayland-eglstream-controller-server-protocol.h"
 
 static struct wl_interface *wl_eglstream_controller_interface_ptr = NULL;
@@ -86,12 +84,9 @@ bind_eglstream_controller (struct wl_client *client,
                                   NULL);
 }
 
-#endif /* HAVE_WAYLAND_EGLSTREAM */
-
 gboolean
 meta_wayland_eglstream_controller_init (MetaWaylandCompositor *compositor)
 {
-#ifdef HAVE_WAYLAND_EGLSTREAM
   /*
    * wl_eglstream_controller_interface is provided by
    * libnvidia-egl-wayland.so.1
@@ -127,7 +122,6 @@ fail:
     dlclose(lib);
 
   g_debug ("WL: Unable to initialize wl_eglstream_controller.");
-#endif
 
   return FALSE;
 }

src/wayland/meta-wayland.c

@@ -398,7 +398,9 @@ meta_wayland_init (void)
                                   meta_xwayland_global_filter,
                                   compositor);
 
+#ifdef HAVE_WAYLAND_EGLSTREAM
   meta_wayland_eglstream_controller_init (compositor);
+#endif
 
   if (meta_should_autostart_x11_display ())
     {