Re: [PATCH] misra: deviate explicit cast for Rule 11.1

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

On 2025-07-29 09:26, Jan Beulich wrote:
> On 28.07.2025 21:17, Nicola Vetrini wrote:
>> On 2025-07-28 20:58, Dmytro Prokopchuk1 wrote:
>>> It works.
>>> The violation "non-compliant cast: implicit cast from 
>>> `void(*)(void*)'
>>> to `void(*)(void*)'" is gone.
>>> 
>> 
>> Great. Now what would be really useful is a way to abstract this more
>> nicely (I was able to write this only by looking at the AST). However
>> noreturn is probably about the only attribute that has a repercussion 
>> on
>> the decl and is safe to cast away, unless I'm mistaken.
> 
> Not sure what you mean by "repercussion" here, and hence my remark may 
> be
> entirely meaningless, but: const and pure are also examples of
> attributes which are safe to cast away, aiui. In fact, given the sheer
> number of attributes, I would be surprised if there weren't more.
> 

Not all attributes influence compatibility of declarations. noreturn is 
a bit special in the sense that gcc and clang don't quite agree on the 
semantics of its various forms, where we follow clang's perspective. See 
https://github.com/llvm/llvm-project/issues/113511 for instance, in 
particular

> So I think the only way in which Clang's behavior is diverging from 
> GCC's here is that we don't support an implicit conversion between 
> pointer-to-function and pointer-to-noreturn function. This should 
> presumably behave somewhat like the implicit conversion between pointer 
> to-function and pointer-to-noexcept-function except that it can 
> apparently be performed implicitly in either direction.

But in any case my remark was more about the future than current plans, 
so there should be no bug here.

-- 
Nicola Vetrini, B.Sc.
Software Engineer
BUGSENG (https://bugseng.com)
LinkedIn: https://www.linkedin.com/in/nicola-vetrini-a42471253