build: Check for drm/drm_fourcc.h too

It's part of the kernel headers package so I did not check for libdrm.

As a side effect I checked the #define to HAVE_DMABUF.

gdk/gdkdisplay.c

@@ -1839,7 +1839,7 @@ gdk_display_get_egl_display (GdkDisplay *self)
 #endif
 }
 
-#ifdef HAVE_LINUX_DMA_BUF_H
+#ifdef HAVE_DMABUF
 static void
 gdk_display_add_dmabuf_downloader (GdkDisplay                *display,
                                    const GdkDmabufDownloader *downloader,
@@ -1877,7 +1877,7 @@ gdk_display_init_dmabuf (GdkDisplay *self)
 
   builder = gdk_dmabuf_formats_builder_new ();
 
-#ifdef HAVE_LINUX_DMA_BUF_H
+#ifdef HAVE_DMABUF
   if (!GDK_DEBUG_CHECK (DMABUF_DISABLE))
     {
       gdk_display_prepare_gl (self, NULL);

gdk/gdkdmabuf.c

@@ -24,7 +24,7 @@
 #include "gdkdmabuftextureprivate.h"
 #include "gdkmemoryformatprivate.h"
 
-#ifdef HAVE_LINUX_DMA_BUF_H
+#ifdef HAVE_DMABUF
 #include <sys/mman.h>
 #include <sys/ioctl.h>
 #include <linux/dma-buf.h>
@@ -550,4 +550,4 @@ gdk_dmabuf_is_disjoint (const GdkDmabuf *dmabuf)
   return FALSE;
 }
 
-#endif  /* HAVE_LINUX_DMA_BUF_H */
+#endif  /* HAVE_DMABUF */

gdk/gdkdmabufformatsbuilder.c

@@ -22,7 +22,7 @@
 
 #include "gdkdmabufformatsprivate.h"
 
-#ifdef HAVE_LINUX_DMA_BUF_H
+#ifdef HAVE_DMABUF
 #include <drm/drm_fourcc.h>
 #endif
 
@@ -121,7 +121,7 @@ gdk_dmabuf_formats_builder_add_format (GdkDmabufFormatsBuilder *self,
                                        guint32                  fourcc,
                                        guint64                  modifier)
 {
-#ifdef HAVE_LINUX_DMA_BUF_H
+#ifdef HAVE_DMABUF
   g_return_if_fail (modifier != DRM_FORMAT_MOD_INVALID);
 #else
   g_return_if_reached ();

gdk/gdkdmabufprivate.h

@@ -39,7 +39,7 @@ struct _GdkDmabufDownloader
                                                                  gsize                           stride);
 };
 
-#ifdef HAVE_LINUX_DMA_BUF_H
+#ifdef HAVE_DMABUF
 const GdkDmabufDownloader *
                         gdk_dmabuf_get_direct_downloader        (void) G_GNUC_CONST;
 

gdk/gdkdmabuftexture.c

@@ -28,7 +28,7 @@
 #include <gdk/gdkgltexturebuilder.h>
 #include <gdk/gdktexturedownloader.h>
 
-#ifdef HAVE_LINUX_DMA_BUF_H
+#ifdef HAVE_DMABUF
 #include <sys/mman.h>
 #include <sys/ioctl.h>
 #include <linux/dma-buf.h>
@@ -129,7 +129,7 @@ gdk_dmabuf_texture_new_from_builder (GdkDmabufTextureBuilder *builder,
                                      gpointer                 data,
                                      GError                 **error)
 {
-#ifdef HAVE_LINUX_DMA_BUF_H
+#ifdef HAVE_DMABUF
   GdkDmabufTexture *self;
   GdkTexture *update_texture;
   GdkDisplay *display;
@@ -210,7 +210,7 @@ gdk_dmabuf_texture_new_from_builder (GdkDmabufTextureBuilder *builder,
 
   return GDK_TEXTURE (self);
 
-#else /* !HAVE_LINUX_DMA_BUF_H */
+#else /* !HAVE_DMABUF */
   g_set_error_literal (error, GDK_DMABUF_ERROR, GDK_DMABUF_ERROR_NOT_AVAILABLE,
                        "dmabuf support disabled at compile-time.");
   return NULL;

gdk/gdkdmabuftexturebuilder.c

@@ -27,7 +27,7 @@
 #include "gdkdmabuftextureprivate.h"
 
 #include <cairo-gobject.h>
-#ifdef HAVE_LINUX_DMA_BUF_H
+#ifdef HAVE_DMABUF
 #include <drm/drm_fourcc.h>
 #else
 #define DRM_FORMAT_MOD_INVALID ((1ULL << 56) - 1)

meson.build

@@ -162,7 +162,6 @@ check_headers = [
   'inttypes.h',
   'linux/input.h',
   'linux/memfd.h',
-  'linux/dma-buf.h',
   'locale.h',
   'memory.h',
   'stdint.h',
@@ -186,8 +185,12 @@ foreach h : check_headers
   endif
 endforeach
 
-if os_linux and not cc.has_header('linux/dma-buf.h')
-  error('OS is Linux, but linux/dma-buf.h not found.')
+if cc.has_header('linux/dma-buf.h') and cc.has_header('drm/drm_fourcc.h')
+  cdata.set('HAVE_DMABUF', 1)
+else
+  if os_linux
+    error('OS is Linux, but linux/dma-buf.h and drm/drm-fourcc.h not found.')
+  endif
 endif
 
 # Maths functions might be implemented in libm