Make __libcpp_verbose_abort() noexcept like std::terminate()

[dougsonos]

Make __libcpp_verbose_abort() noexcept (it is already noreturn), to match std::terminate(). Clang's function effect analysis can use this to ignore such functions as being beyond its scope. (See #99656)

[llvmbot]

@llvm/pr-subscribers-libcxx

Author: Doug Wyatt (dougsonos)

Changes

Make __libcpp_verbose_abort() noexcept (it is already noreturn), to match std::terminate(). Clang's function effect analysis can use this to ignore such functions as being beyond its scope. (See #99656)

---

Full diff: https://github.com/llvm/llvm-project/pull/109151.diff

1 Files Affected:

• (modified) libcxx/include/__verbose_abort (+2-1)

diff --git a/libcxx/include/__verbose_abort b/libcxx/include/__verbose_abort
index 244278aec652d2..45a0add493c17d 100644
--- a/libcxx/include/__verbose_abort
+++ b/libcxx/include/__verbose_abort
@@ -21,7 +21,8 @@ _LIBCPP_BEGIN_NAMESPACE_STD
 // This function should never be called directly from the code -- it should only be called through
 // the _LIBCPP_VERBOSE_ABORT macro.
 [[__noreturn__]] _LIBCPP_AVAILABILITY_VERBOSE_ABORT _LIBCPP_OVERRIDABLE_FUNC_VIS
-_LIBCPP_ATTRIBUTE_FORMAT(__printf__, 1, 2) void __libcpp_verbose_abort(const char* __format, ...);
+_LIBCPP_ATTRIBUTE_FORMAT(__printf__, 1, 2) void __libcpp_verbose_abort(const char* __format, ...)
+_NOEXCEPT;
 
 // _LIBCPP_VERBOSE_ABORT(format, args...)
 //

[github-actions]

✅ With the latest revision this PR passed the C/C++ code formatter.

[dougsonos]

Oops, I forgot to make the implementation noexcept too. This highlights that the question here is whether changing this interface to noexcept is going to break anything...

[ldionne]

This makes sense to me, however this is technically a breaking change because in the past we have advertised __libcpp_verbose_abort as being overridable (that's why it was a weak def).

We'd also want to add a release note for this change in libcxx/docs/ReleaseNotes/20.rst, probably under Deprecations and Removals.

Pinging @llvm/libcxx-vendors for awareness.

[dougsonos]

Any pointers on what's going on with the test builds? I click Details and just see "job failed".

[ldionne]

Any pointers on what's going on with the test builds? I click Details and just see "job failed".

Our CI is currently in a really bad state. Workers are failing to connect. This has been going on for a few days and we're trying to resolve the issue. Sorry for the inconvenience.

[ldionne]

Please rebase onto main to re-trigger CI. The CI instability should be resolved now.