aaron.ballman added a comment.

In D122895#3510165 <https://reviews.llvm.org/D122895#3510165>, @dexonsmith 
wrote:

> For additional context to my questions above, even though open source clang 
> hasn't been using `-Wstrict-prototypes`, Xcode has had it on-by-default in 
> new projects since sometime in 2017, with project modernizations to turn it 
> on for old projects.

Thanks, that's very good to know! And also, thank you for raising the questions 
here, I appreciate the discussion.

> Warning on block and function definitions such as `^(){}` and `void f1() {}`, 
> which are pedantically lacking a prototype but the compiler knows there are 
> exactly zero parameters, would be super noisy for users.
>
> Unless I read the RFC too quickly, it doesn't look like it's adding any 
> value, since these aren't going to change meaning. Is it possible to revert 
> this part of the change?

`-Wstrict-prototypes` is now a pedantic deprecation warning that fires any time 
you form a function type which has no prototype, which was discussed in the RFC 
(https://discourse.llvm.org/t/rfc-enabling-wstrict-prototypes-by-default-in-c/60521/38?u=aaronballman):

  Change -Wstrict-prototypes to diagnose functions without a prototype that 
don’t change behavior in C2x, it remains off-by-default but is automatically 
enabled by -pedantic as it’s still warning the user about a deprecation.

However, I think the blocks behavior is a bug based on this: 
https://github.com/llvm/llvm-project/blob/main/clang/lib/Sema/SemaType.cpp#L728 
and I'd be more than happy to fix that, as I'm not checking that condition 
here: 
https://github.com/llvm/llvm-project/blob/main/clang/lib/Sema/SemaType.cpp#L5579
 which seems like a pretty obvious thing to be checking for before warning 
about not having a strict prototype.

But I'm pretty insistent on warning about the other case as it does use 
functions without a prototype and we need *some* blanket warning for use of a 
deprecated feature for folks who want to be strictly conforming. It sounds like 
Apple may want to no longer enable `-Wstrict-prototypes` by default as it's 
shifted to be a more pedantic warning than it was before -- would that be a 
viable option for you (can you use project modernizations to turn it back off 
for old projects)?


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D122895/new/

https://reviews.llvm.org/D122895

_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

Reply via email to