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

[Randy Dunlap]

On 2/21/20 9:49 PM, Masahiro Yamada wrote:
> On Sat, Feb 22, 2020 at 2:25 PM Randy Dunlap <rdunlap at infradead.org> wrote:
>>
>> On 2/21/20 8:53 PM, Masahiro Yamada wrote:
>>> On Sat, Feb 22, 2020 at 1:43 PM Masahiro Yamada <masahiroy at kernel.org> wrote:
>>>>
>>>> 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.
>>>>
>>>
>>>
>>> I just tested it.
>>>
>>> This is not a problem for header test
>>> because cmd_hdrtest uses '-S' instead of '-c'.
>>>
>>> If '-c' were used, we would see a similar error.
>>>
>>>
>>> So, gsplit-dwarf is OK.
>>
>> Yes, works for me also.
>>
>> (I think you have a faster build machine that I do. I began the build
>> almost immediately after reading your email. :)
> 
> 
> I use a reasonable PC for my development.
> (core-i9 with 4 physical cores)
> 
> 
> I just compiled under i915/ with this command:
> 
> make drivers/gpu/drm/i915/

Good trick.  I did a full build.


-- 
~Randy