bugprone-suspicious-semicolon false positive on `if constexpr ()` with template

[llvmbot]

Bugzilla Link	35824
Resolution	FIXED
Resolved on	Nov 27, 2019 11:13
Version	unspecified
OS	Linux
Depends On	#31551
Attachments	repro file
Reporter	LLVM Bugzilla Contributor
CC	@daphnediane,@JVApen,@pavelkryukov

Extended Description

repro file attached

[llvmbot]

assigned to @Xazax-hun

[pavelkryukov]

I still have this issue on Clang-Tidy 6.0.0

[llvmbot]

BTW, the check is now called bugprone-suspicious-semicolon.

[Xazax-hun]

A fix is proposed in https://reviews.llvm.org/D46027 with some questions.

[daphnediane]

Appears to be related to 32203 as well.

[Xazax-hun]

Sorry for the inactivity. Feel free to commandeer the patch, I have no idea when can I return to solve this problem.

In the meantime https://reviews.llvm.org/D46233 was merged and https://reviews.llvm.org/D46234 was proposed as an alternative fix.

[pavelkryukov]

Still here in LLVM 8 distribution

[JVApen]

Still/Again there in trunk: https://godbolt.org/z/xNtkWX

[llvmbot]

I just ran into this issue with the following code:

template<typename ERROR = fatal_error, typename... ARGS>
[[noreturn]] auto
fatal(ARGS &&... args) -> void
{
    details::debug::print<0>(
        magenta, "FATAL", std::forward<ARGS>(args)...);

    if constexpr (autosar_compliant) { // <------ triggers false positive
        throw ERROR{};
    }

#ifndef BSL_FATAL_EXIT_INSTEAD_OF_ABORT
std::abort(); //NOSONAR
#else
std::exit(1); //NOSONAR
#endif
}

It seems that this bug has been in Clang Tidy for come time. Are there any plans to address this?

[Xazax-hun]

https://reviews.llvm.org/D46027 is still there to work this issue around for more than a year. It comes at the cost of some false negatives. Unfortunately, I do not have time to work on some other solutions. If no one volunteers to pick it up I would suggest to merge https://reviews.llvm.org/D46027.

[Xazax-hun]

Ok, the quick fix should now be committed in 5c5e860 .