clang-tidy: modernize-use-trailing-return-type: missing void

[FStefanni]

Hi,

I do not know if this is the intended behavior or a bug, but the warning (and relative auto-fixes) of the modernize-use-trailing-return-type are not triggered for functions returning void.

I suggest to support also these signatures (maybe with an option for backward compatibility?) to allow to have a complete homogeneous code.

Regards.

[llvmbot]

@llvm/issue-subscribers-clang-tidy

[Izaron]

Hi! This is the intended behaviour: there is a filter for void type and a test asserting that the check won't trigger on void.

Code:

llvm-project/clang-tools-extra/clang-tidy/modernize/UseTrailingReturnTypeCheck.cpp

Line 388 in 1ae4051

unless(anyOf(hasTrailingReturn(), returns(voidType()),

Test:

llvm-project/clang-tools-extra/test/clang-tidy/checkers/modernize/use-trailing-return-type.cpp

Lines 582 to 584 in 1ae4051

	void c();
	void c(int arg);
	void c(int arg) { return; }

Unfortunately I'm not a user of this check, so I don't know: do we really need an option to trigger on void return type?..

I'll make this option and send the patch, let's see what other devs say =)

[FStefanni]

Hi @Izaron,

thank you. I'll wait for your updates.

I suggest an options so the patch will be backward compatible, but for me what is important is to be able to warn also for void.

Imho, the code should look consistent for better clarity, so if I decide to put return types at the beginning, I will put all of them at the beginning. vice versa, I will put all of them at the end. So when I am searching for what a function returns, I know immediately where to look for. I truly do not understand why I should want to mix things up...
But I understand that these are just matters of "code style" (i.e. personal tastes), so adding options to let people free to choose should be the best.

Regards

[Izaron]

A possible fix: https://reviews.llvm.org/D135822