[libcxx-commits] [libcxx] Make __libcpp_verbose_abort() noexcept like std::terminate() (PR #109151)

[Doug Wyatt via libcxx-commits]

https://github.com/dougsonos updated https://github.com/llvm/llvm-project/pull/109151

>From b99a59872adca1a71631c877396151965232b6e6 Mon Sep 17 00:00:00 2001
From: Doug Wyatt <dwyatt at apple.com>
Date: Wed, 18 Sep 2024 07:19:02 -0700
Subject: [PATCH] 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.

---
 libcxx/docs/ReleaseNotes/20.rst                               | 3 +++
 libcxx/include/__verbose_abort                                | 2 +-
 libcxx/src/verbose_abort.cpp                                  | 2 +-
 .../assertions/customize_verbose_abort.link-time.pass.cpp     | 4 +---
 libcxx/test/support/check_assertion.h                         | 2 +-
 5 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/libcxx/docs/ReleaseNotes/20.rst b/libcxx/docs/ReleaseNotes/20.rst
index 82c8286b69e23c..70e1f56df1b627 100644
--- a/libcxx/docs/ReleaseNotes/20.rst
+++ b/libcxx/docs/ReleaseNotes/20.rst
@@ -77,6 +77,9 @@ Deprecations and Removals
   supported as an extension anymore, please migrate any code that uses e.g. ``std::vector<const T>`` to be
   standards conforming.
 
+- The function ``__libcpp_verbose_abort()`` is now ``noexcept``, to match ``std::terminate()``. (The combination of
+  ``noexcept`` and ``[[noreturn]]`` has special significance for function effects analysis.)
+
 Upcoming Deprecations and Removals
 ----------------------------------
 
diff --git a/libcxx/include/__verbose_abort b/libcxx/include/__verbose_abort
index 244278aec652d2..73295cae426102 100644
--- a/libcxx/include/__verbose_abort
+++ b/libcxx/include/__verbose_abort
@@ -21,7 +21,7 @@ _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...)
 //
diff --git a/libcxx/src/verbose_abort.cpp b/libcxx/src/verbose_abort.cpp
index 719134e2ae554d..0019063405a810 100644
--- a/libcxx/src/verbose_abort.cpp
+++ b/libcxx/src/verbose_abort.cpp
@@ -28,7 +28,7 @@ extern "C" void android_set_abort_message(const char* msg);
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-_LIBCPP_WEAK void __libcpp_verbose_abort(char const* format, ...) {
+_LIBCPP_WEAK void __libcpp_verbose_abort(char const* format, ...) noexcept {
   // Write message to stderr. We do this before formatting into a
   // buffer so that we still get some information out if that fails.
   {
diff --git a/libcxx/test/libcxx/assertions/customize_verbose_abort.link-time.pass.cpp b/libcxx/test/libcxx/assertions/customize_verbose_abort.link-time.pass.cpp
index 9298a1e365fca4..2d30a39e37b159 100644
--- a/libcxx/test/libcxx/assertions/customize_verbose_abort.link-time.pass.cpp
+++ b/libcxx/test/libcxx/assertions/customize_verbose_abort.link-time.pass.cpp
@@ -15,9 +15,7 @@
 #include <__verbose_abort>
 #include <cstdlib>
 
-void std::__libcpp_verbose_abort(char const*, ...) {
-  std::exit(EXIT_SUCCESS);
-}
+void std::__libcpp_verbose_abort(char const*, ...) noexcept { std::exit(EXIT_SUCCESS); }
 
 int main(int, char**) {
   std::__libcpp_verbose_abort("%s", "message");
diff --git a/libcxx/test/support/check_assertion.h b/libcxx/test/support/check_assertion.h
index 47ebfeeeefc0f4..a279400d651b48 100644
--- a/libcxx/test/support/check_assertion.h
+++ b/libcxx/test/support/check_assertion.h
@@ -334,7 +334,7 @@ class DeathTest {
 };
 
 #ifdef _LIBCPP_VERSION
-void std::__libcpp_verbose_abort(char const* format, ...) {
+void std::__libcpp_verbose_abort(char const* format, ...) noexcept {
   va_list args;
   va_start(args, format);