| Message ID | 1651262112-29664-1-git-send-email-quic_jhugo@quicinc.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm: drm_gem.h: Add explicit includes for DEFINE_DRM_GEM_FOPS | expand |
On Fri, 29 Apr 2022, Jeffrey Hugo <quic_jhugo@quicinc.com> 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. BR, Jani. > > Signed-off-by: Jeffrey Hugo <quic_jhugo@quicinc.com> > --- > 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;
On Mon, May 02, 2022 at 06:41:39PM +0300, Jani Nikula wrote: > On Fri, 29 Apr 2022, Jeffrey Hugo <quic_jhugo@quicinc.com> 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. iow, I concur. -Daniel > > BR, > Jani. > > > > > > > Signed-off-by: Jeffrey Hugo <quic_jhugo@quicinc.com> > > --- > > 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
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@quicinc.com> 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@quicinc.com> >>> --- >>> 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 >
On Wed, May 04, 2022 at 07:58:38AM -0600, Jeffrey Hugo wrote: > 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@quicinc.com> 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. I think a standalone header for gem fops or so might be an option. We also have some macro iirc for standard stuff in drm_driver (or at least had in the past, maybe that's cleaned up now better). That would allow drivers to include this monster header that pulls in a lot of things in the one place they define their file ops, and nowhere else. I think that would cover everything we'd want to achieve? But would be a bit of churn to roll out everywhere. -Daniel > > > > > iow, I concur. > > -Daniel > > > > > > > > BR, > > > Jani. > > > > > > > > > > > > > > > > > Signed-off-by: Jeffrey Hugo <quic_jhugo@quicinc.com> > > > > --- > > > > 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 > > >
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;
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. Signed-off-by: Jeffrey Hugo <quic_jhugo@quicinc.com> --- include/drm/drm_gem.h | 2 ++ 1 file changed, 2 insertions(+)