Re: 'set but unused' breaks drm-*-kmod

On 4/21/22 6:45 AM, Emmanuel Vadot wrote:
> On Thu, 21 Apr 2022 08:51:26 -0400
> Michael Butler <imb@protected-networks.net> wrote:
> 
>> On 4/21/22 03:42, Emmanuel Vadot wrote:
>>>
>>>    Hello Michael,
>>>
>>> On Wed, 20 Apr 2022 23:39:12 -0400
>>> Michael Butler <imb@protected-networks.net> wrote:
>>>
>>>> Seems this new requirement breaks kmod builds too ..
>>>>
>>>> The first of many errors was (I stopped chasing them all for lack of
>>>> time) ..
>>>>
>>>> --- amdgpu_cs.o ---
>>>> /usr/ports/graphics/drm-devel-kmod/work/drm-kmod-drm_v5.7.19_3/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c:1210:26:
>>>> error: variable 'priority' set but not used
>>>> [-Werror,-Wunused-but-set-variable]
>>>>            enum drm_sched_priority priority;
>>>>                                    ^
>>>> 1 error generated.
>>>> *** [amdgpu_cs.o] Error code 1
>>>>
>>>
>>>    How are you building the port, directly or with PORTS_MODULES ?
>>>    I do make passes on the warning for drm and I did for set-but-not-used
>>> case but unfortunately this option doesn't exists in 13.0 so I couldn't
>>> apply those in every branch.
>>
>> I build this directly on -current. I'm guessing that these are what
>> triggered this behaviour:
>>
>> commit 8b83d7e0ee54416b0ee58bd85f9c0ae7fb3357a1
>> Author: John Baldwin <jhb@FreeBSD.org>
>> Date:   Mon Apr 18 16:06:27 2022 -0700
>>
>>       Make -Wunused-but-set-variable a fatal error for clang 13+ for
>> kernel builds.
>>
>>       Reviewed by:    imp, emaste
>>       Differential Revision:  https://reviews.freebsd.org/D34949
>>
>> commit 615d289ffefe2b175f80caa9b1e113c975576472
>> Author: John Baldwin <jhb@FreeBSD.org>
>> Date:   Mon Apr 18 16:06:14 2022 -0700
>>
>>       Re-enable set but not used warnings for kernel builds.
>>
>>       make tinderbox now passes with this warning enabled as a fatal error,
>>       so revert the change to hide it in preparation for making it fatal.
>>
>>       This reverts commit e8e691983bb75e80153b802f47733f1531615fa2.
>>
>>       Reviewed by:    imp, emaste
>>       Differential Revision:  https://reviews.freebsd.org/D34948
>>
>>
> 
>   Ok I see,
> 
>   I won't have time until monday (maybe tuesday to fix this) but if
> someone wants to beat me to it we should add some new CWARNFLAGS for
> each problematic files in the 5.4-lts and 5.7-table branches of
> drm-kmod (master which is following 5.10 is already good) only
> if $ {COMPILER_VERSION} >= 130000.

There is already a helper you can use that deals with compiler versions:

CWARNFLAGS+= ${NO_WUNUSED_BUT_SET_VARIABLE}

or some such.

-- 
John Baldwin