[Intel-gfx] [PATCH] drm/i915: fix header test with GCOV

[Masahiro Yamada]

Hi Jani,

On Fri, Feb 21, 2020 at 7:54 PM Jani Nikula <jani.nikula at intel.com> wrote:
>
> $(CC) with $(CFLAGS_GCOV) assumes the output filename with .gcno suffix
> appended is writable. This is not the case when the output filename is
> /dev/null:
>
>   HDRTEST drivers/gpu/drm/i915/display/intel_frontbuffer.h
> /dev/null:1:0: error: cannot open /dev/null.gcno
>   HDRTEST drivers/gpu/drm/i915/display/intel_ddi.h
> /dev/null:1:0: error: cannot open /dev/null.gcno
> make[5]: *** [../drivers/gpu/drm/i915/Makefile:307:
> drivers/gpu/drm/i915/display/intel_ddi.hdrtest] Error 1
> make[5]: *** Waiting for unfinished jobs....
> make[5]: *** [../drivers/gpu/drm/i915/Makefile:307:
> drivers/gpu/drm/i915/display/intel_frontbuffer.hdrtest] Error 1
>
> Filter out $(CFLAGS_GVOC) from the header test $(c_flags) as they don't
> make sense here anyway.



Is GCOV the only case that produces a separate file?

Could you also test CONFIG_DEBUG_INFO_SPLIT, please ?


The GCC manual says this:

-gsplit-dwarf

   Separate as much DWARF debugging information as possible into a
separate output
   file with the extension .dwo. This option allows the build system
to avoid linking
   files with debug information. To be useful, this option requires a debugger
   capable of reading .dwo files.




If this does not work, filtering flags
does not seem to be a maintainable way.




>
> References: http://lore.kernel.org/r/d8112767-4089-4c58-d7d3-2ce03139858a@infradead.org
> Reported-by: Randy Dunlap <rdunlap at infradead.org>
> Fixes: c6d4a099a240 ("drm/i915: reimplement header test feature")
> Cc: Masahiro Yamada <masahiroy at kernel.org>
> Signed-off-by: Jani Nikula <jani.nikula at intel.com>
> ---
>  drivers/gpu/drm/i915/Makefile | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
> index b314d44ded5e..bc28c31c4f78 100644
> --- a/drivers/gpu/drm/i915/Makefile
> +++ b/drivers/gpu/drm/i915/Makefile
> @@ -301,7 +301,7 @@ extra-$(CONFIG_DRM_I915_WERROR) += \
>                 $(shell cd $(srctree)/$(src) && find * -name '*.h')))
>
>  quiet_cmd_hdrtest = HDRTEST $(patsubst %.hdrtest,%.h,$@)
> -      cmd_hdrtest = $(CC) $(c_flags) -S -o /dev/null -x c /dev/null -include $<; touch $@
> +      cmd_hdrtest = $(CC) $(filter-out $(CFLAGS_GCOV), $(c_flags)) -S -o /dev/null -x c /dev/null -include $<; touch $@
>
>  $(obj)/%.hdrtest: $(src)/%.h FORCE
>         $(call if_changed_dep,hdrtest)
> --
> 2.20.1
>


-- 
Best Regards
Masahiro Yamada