[Intel-gfx] [PATCH i-g-t 8/8] tests/kms_fbc_crc: ensure context is initialized correctly

[Thomas Wood]

On 4 November 2015 at 19:36, Zanoni, Paulo R <paulo.r.zanoni at intel.com> wrote:
> Em Seg, 2015-11-02 às 11:48 +0000, Thomas Wood escreveu:
>> Initialization was included in commit a976d7e (tests/kms_fbc_crc:
>> refactor context
>> handling code), but won't be executed since it is declared before the
>> first
>> label within a switch statement.
>>
>> kms_fbc_crc.c:178:2: warning: ‘context’ may be used uninitialized in
>> this function [-Wmaybe-uninitialized]
>>   rendercopy(batch, context,
>>   ^
>> kms_fbc_crc.c:271:22: note: ‘context’ was declared here
>>    drm_intel_context *context = NULL;
>
> I don't see these warnings here. Which compiler do you use?

The warning requires -Wmaybe-uninitialized and an appropriate
optimisation level to be enabled. -Wmaybe-uninitialized is currently
disabled by the debug cflags in intel-gpu-tools due to previous false
positives, but it looks like the situation with regards to this has
improved and so it may be time to re-enable it.


>
> pzanoni at panetone:~/nfs/intel-gpu-tools/tests$ gcc --version
> gcc (Debian 5.2.1-22) 5.2.1 20151010
>
> The weird part is that it was initialized during the declaration, so
> the declaration is valid yet the initialization is not? Anyway, your
> change removes the ambiguity of the situation and avoid citations of
> the C standard, so:
>
> Reviewed-by: Paulo Zanoni <paulo.r.zanoni at intel.com>
>
>>
>>                       ^
>> Cc: Paulo Zanoni <paulo.r.zanoni at intel.com>
>> Signed-off-by: Thomas Wood <thomas.wood at intel.com>
>> ---
>>  tests/kms_fbc_crc.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/tests/kms_fbc_crc.c b/tests/kms_fbc_crc.c
>> index d580a94..02e95e5 100644
>> --- a/tests/kms_fbc_crc.c
>> +++ b/tests/kms_fbc_crc.c
>> @@ -255,6 +255,7 @@ static void test_crc(data_t *data, enum test_mode
>> mode)
>>  {
>>       uint32_t crtc_id = data->output->config.crtc->crtc_id;
>>       uint32_t handle = data->fb[0].gem_handle;
>> +     drm_intel_context *context = NULL;
>>
>>       igt_assert(fbc_enabled(data));
>>
>> @@ -268,7 +269,6 @@ static void test_crc(data_t *data, enum test_mode
>> mode)
>>       }
>>
>>       switch (mode) {
>> -             drm_intel_context *context = NULL;
>>       case TEST_PAGE_FLIP:
>>               break;
>>       case TEST_MMAP_CPU: