Re: [PATCH 2/2] MdeModulePkg/UdfDxe: suppress incorrect compiler warning in ReadFile()

[Ard Biesheuvel <ard.biesheuvel@linaro.org>]

On 13 September 2017 at 11:49, Laszlo Ersek <lersek@redhat.com> wrote:
> On 09/13/17 08:43, Zeng, Star wrote:
>> Beyond the Rb (I do not want to block this patch series), I am curious about one question.
>>
>> There may be more this kind of workarounds to fix the build failure.
>> Is it possible to disable the warning (like below example for VS) for specific version of GCC for this kind of false alarm?
>>
>>
>> ProcessorBind.h:
>> #if defined(_MSC_EXTENSIONS)
>>
>> ...
>>
>> #if _MSC_VER == 1800 || _MSC_VER == 1900
>>
>> //
>> // Disable these warnings for VS2013.
>> //
>>
>> //
>> // This warning is for potentially uninitialized local variable, and it may cause false
>> // positive issues in VS2013 and VS2015 build
>> //
>> #pragma warning ( disable : 4701 )
>>
>> //
>> // This warning is for potentially uninitialized local pointer variable, and it may cause
>> // false positive issues in VS2013 and VS2015 build
>> //
>> #pragma warning ( disable : 4703 )
>>
>> #endif
>>
>> #endif
>
> I think starting with gcc-4.6, gcc supports the "diagnostics" pragma,
> which can be used to suppress warnings.
>
> Unfortunately, there's no pragma to suppress *only* the incorrect
> warnings :) So if we set the pragma, we could lose even those warnings
> that point out real bugs.
>

That applies to the VS case as well. But I think doing this for older
GCCs is fine, most EDK2 developers use a newer version anyway, so we
will not lose any coverage by doing so.