On 5/4/2022 3:38 AM, Daniel Vetter wrote:
On Mon, May 02, 2022 at 06:41:39PM +0300, Jani Nikula wrote:
On Fri, 29 Apr 2022, Jeffrey Hugo <quic_jhugo@xxxxxxxxxxx> wrote:
DEFINE_DRM_GEM_FOPS() references drm functions from other headers. For
example drm_open() is defined in drm_file.h and drm_ioctl() is defined
in drm_ioctl.h. Since drm_gem.h doesn't include these headers, it
relies on an implicit include from the .c file to have included these
required headers before DEFINE_DRM_GEM_FOPS() gets used. Relying on
these implicit includes can cause build failures for new code that
doesn't know about these requirements, and can lead to future problems
if the headers ever get restructured as there will be a need to update
every downstream file that includes drm_gem.h.
Lets fix this explicitly including the required headers in drm_gem.h so
that code that includes drm_gem.h does not need to worry about these
implicit dependencies.
In the general case, I tend to agree, but in this specific instance I
think I'd err on the side of fewer includes. I think the more likely
outcome here is accumulating implicit dependencies on symbols from
drm_file.h and drm_ioctl.h by including drm_gem.h only!
I do think headers need to be self-contained, and we actually enforce
this in i915 (see HDRTEST in drivers/gpu/drm/i915/Makefile), but not to
the point of macro expansions.
Yeah we abuse macros in a bunch of places to untangle header dependencies,
so then going back and pulling in all the headers back in feels a bit
silly and defeats the point.
Fair enough. I'll consider this NAK'd
I've been pondering alternate solutions, but haven't come up with any.
I guess, for now, the status quo will remain.
iow, I concur.
-Daniel
BR,
Jani.
Signed-off-by: Jeffrey Hugo <quic_jhugo@xxxxxxxxxxx>
---
include/drm/drm_gem.h | 2 ++
1 file changed, 2 insertions(+)
diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h
index 9d7c61a..1cbe3d8 100644
--- a/include/drm/drm_gem.h
+++ b/include/drm/drm_gem.h
@@ -37,6 +37,8 @@
#include <linux/kref.h>
#include <linux/dma-resv.h>
+#include <drm/drm_file.h>
+#include <drm/drm_ioctl.h>
#include <drm/drm_vma_manager.h>
struct iosys_map;
--
Jani Nikula, Intel Open Source Graphics Center
