Re: MISRA C Rule 5.3 violation - shadowing in mctelem.c

[Nicola Vetrini <nicola.vetrini@bugseng.com>]

On 2024-06-19 15:42, Jan Beulich wrote:
> On 19.06.2024 15:23, Nicola Vetrini wrote:
>> I was looking at the shadowing due to the struct identifier and the
>> local variables "mctctl" in x86/cpu/mcheck/mctelem.c (see [1], the
>> second report). This kind of shadowing seems very intentional, and the
>> initial naive approach I devised was to simply rename the local
>> variables.
>> This, however, results in build breakages, as sometimes the shadowed
>> name seems to be used for accessing the global struct (unless I'm
>> missing something), and as a result changing the name of the locals is
>> not possible, at least not without further modifications to this file,
>> which aren't obvious to me.
>> 
>> It would be really helpful if you could point me to either:
>> - avoid the shadowing in some way that does not occur to me at the
>> moment;
> 
> Could you please be more specific about the issues you encountered? I
> hope you don't expect everyone reading this request of yours to (try 
> to)
> redo what you did. The only thing I could vaguely guess is that maybe
> you went a little too far with the renaming. Plus, just from looking at
> the grep output, did you try to simply move down the file scope 
> variable?
> It looks like all shadowing instances are ahead of any uses of the
> variable (but I may easily be overlooking an important line 
> contradicting
> that pattern).
> 

I think I found a way to refactor it without breaking the build, though 
I'm not sure whether it preserves the semantics of the code. I will send 
an RFC patch. Sorry for the noise.

>> - deviate this file, as many similar files in x86/cpu are already
>> deviated.
> 
> I question the presence of these in those files. They were apparently 
> all
> added when the files were introduced, and said commit - from Simone, 
> acked
> by Stefano - came with no justification at all.
> 
> Jan

-- 
Nicola Vetrini, BSc
Software Engineer, BUGSENG srl (https://bugseng.com)