[libcxx-commits] [libcxx] [libc++][hardening][NFC] Introduce `_LIBCPP_VERBOSE_TRAP` macro. (PR #148262)

[Konstantin Varlamov via libcxx-commits]

https://github.com/var-const updated https://github.com/llvm/llvm-project/pull/148262

>From 6708ebf6020c59a4832aac95cb9524d533798100 Mon Sep 17 00:00:00 2001
From: Konstantin Varlamov <varconst at apple.com>
Date: Fri, 11 Jul 2025 10:17:36 -0700
Subject: [PATCH] [libc++][hardening][NFC] Introduce `_LIBCPP_VERBOSE_TRAP`
 macro.

Split out the calls to `__builtin_verbose_trap` into a separate header.
This is just a refactoring to make the code a bit more structured.
---
 libcxx/include/CMakeLists.txt                 |  1 +
 libcxx/include/__verbose_trap                 | 36 +++++++++++++++++++
 .../vendor/llvm/default_assertion_handler.in  | 14 ++------
 3 files changed, 39 insertions(+), 12 deletions(-)
 create mode 100644 libcxx/include/__verbose_trap

diff --git a/libcxx/include/CMakeLists.txt b/libcxx/include/CMakeLists.txt
index c8e6d28584623..f79edc9e32599 100644
--- a/libcxx/include/CMakeLists.txt
+++ b/libcxx/include/CMakeLists.txt
@@ -944,6 +944,7 @@ set(files
   __vector/vector_bool.h
   __vector/vector_bool_formatter.h
   __verbose_abort
+  __verbose_trap
   algorithm
   any
   array
diff --git a/libcxx/include/__verbose_trap b/libcxx/include/__verbose_trap
new file mode 100644
index 0000000000000..13ea727738c3b
--- /dev/null
+++ b/libcxx/include/__verbose_trap
@@ -0,0 +1,36 @@
+// -*- C++ -*-
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP___VERBOSE_TRAP
+#define _LIBCPP___VERBOSE_TRAP
+
+#include <__config>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+#if __has_builtin(__builtin_verbose_trap)
+// AppleClang shipped a slightly different version of __builtin_verbose_trap from the upstream
+// version before upstream Clang actually got the builtin.
+// TODO: Remove once AppleClang supports the two-arguments version of the builtin.
+#  if defined(_LIBCPP_APPLE_CLANG_VER) && _LIBCPP_APPLE_CLANG_VER < 1700
+#    define _LIBCPP_VERBOSE_TRAP(message) __builtin_verbose_trap(message)
+#  else
+#    define _LIBCPP_VERBOSE_TRAP(message) __builtin_verbose_trap("libc++", message)
+#  endif
+#else
+#  define _LIBCPP_VERBOSE_TRAP(message) ((void)message, __builtin_trap())
+#endif
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP___VERBOSE_TRAP
diff --git a/libcxx/vendor/llvm/default_assertion_handler.in b/libcxx/vendor/llvm/default_assertion_handler.in
index 1d6b21fc6bb45..90b202a2dae57 100644
--- a/libcxx/vendor/llvm/default_assertion_handler.in
+++ b/libcxx/vendor/llvm/default_assertion_handler.in
@@ -15,6 +15,7 @@
 #  include <__cxx03/__verbose_abort>
 #else
 #  include <__config>
+#  include <__verbose_trap>
 #  include <__verbose_abort>
 #endif
 
@@ -28,18 +29,7 @@
 
 #else
 
-#  if __has_builtin(__builtin_verbose_trap)
-// AppleClang shipped a slightly different version of __builtin_verbose_trap from the upstream
-// version before upstream Clang actually got the builtin.
-// TODO: Remove once AppleClang supports the two-arguments version of the builtin.
-#    if defined(_LIBCPP_APPLE_CLANG_VER) && _LIBCPP_APPLE_CLANG_VER < 1700
-#      define _LIBCPP_ASSERTION_HANDLER(message) __builtin_verbose_trap(message)
-#    else
-#      define _LIBCPP_ASSERTION_HANDLER(message) __builtin_verbose_trap("libc++", message)
-#    endif
-#  else
-#    define _LIBCPP_ASSERTION_HANDLER(message) ((void)message, __builtin_trap())
-#  endif
+#  define _LIBCPP_ASSERTION_HANDLER(message) _LIBCPP_VERBOSE_TRAP(message)
 
 #endif // _LIBCPP_HARDENING_MODE == _LIBCPP_HARDENING_MODE_DEBUG