[PATCH] D139195: [-Wmissing-noreturn] Detect non-void noreturn function candidates

Fri Dec 2 07:56:47 PST 2022

steakhal planned changes to this revision.
steakhal added a comment.

In D139195#3966675 <https://reviews.llvm.org/D139195#3966675>, @aaron.ballman wrote:

>> Previously, only void returning functions were considered for noreturn attribute candidates. This patch removes this artificial restriction.
>
> C2x 6.7.12.6p6: The implementation should produce a diagnostic message for a function declared with a noreturn attribute that appears to be capable of returning to its caller.
>
> p7 has an example showing `[[noreturn]] int h(void);` with the comment "Implementations are similarly encouraged to diagnose the declaration of h() because it appears capable of returning to its caller due to the non-void return type."
>
> So is this really an artificial restriction? To me, putting the `noreturn` attribute on a function with a return type makes no sense whatsoever. The interface is saying "I promise that calling me will not return" and "when I return, this is the type of the value I will give you."

Hmm, I implicitly took the `__attribute__((noreturn))` suggestion and the non-void return type as a code-smell for the exact same reason.
You are right, we should have a clean diagnostic message for these cases instead of this implied suggestion.
IDK why I haven't thought about this 😅

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https://reviews.llvm.org/D139195