[libc++abi] Fix test failures with GCC 14

Author: philnik777

libcxxabi/include/cxxabi.h

@@ -77,6 +77,11 @@ extern _LIBCXXABI_FUNC_VIS void __cxa_end_cleanup();
 #endif
 extern _LIBCXXABI_FUNC_VIS std::type_info *__cxa_current_exception_type();
 
+// GNU extension
+// Calls `terminate` with the current exception being caught. This function is used by GCC when a `noexcept` function
+// throws an exception inside a try/catch block and doesn't catch it.
+extern _LIBCXXABI_FUNC_VIS _LIBCXXABI_NORETURN void __cxa_call_terminate(void*) throw();
+
 // 2.5.4 Rethrowing Exceptions
 extern _LIBCXXABI_FUNC_VIS _LIBCXXABI_NORETURN void __cxa_rethrow();
 

libcxxabi/lib/itanium-exceptions.exp

@@ -5,6 +5,7 @@ ___cxa_begin_catch
 ___cxa_call_unexpected
 ___cxa_current_exception_type
 ___cxa_end_catch
+___cxa_call_terminate
 ___cxa_free_dependent_exception
 ___cxa_free_exception
 ___cxa_get_exception_ptr

libcxxabi/src/cxa_exception.cpp

@@ -589,6 +589,11 @@ void __cxa_end_catch() {
     }
 }
 
+void __cxa_call_terminate(void* unwind_arg) throw() {
+  __cxa_begin_catch(unwind_arg);
+  std::terminate();
+}
+
 // Note:  exception_header may be masquerading as a __cxa_dependent_exception
 //        and that's ok.  exceptionType is there too.
 //        However watch out for foreign exceptions.  Return null for them.

libcxxabi/test/catch_const_pointer_nullptr.pass.cpp

@@ -8,16 +8,11 @@
 
 // UNSUPPORTED: no-exceptions
 
-#include <cassert>
-
-// Clang emits  warnings about exceptions of type 'Child' being caught by
-// an earlier handler of type 'Base'. Congrats clang, you've just
-// diagnosed the behavior under test.
-#if defined(__clang__)
-#pragma clang diagnostic ignored "-Wexceptions"
-#endif
+// Clang and GCC emit warnings about exceptions of type 'Child' being caught by
+// an earlier handler of type 'Base'.
+// ADDITIONAL_COMPILE_FLAGS: -Wno-exceptions
 
-#if __has_feature(cxx_nullptr)
+#include <cassert>
 
 struct A {};
 
@@ -124,18 +119,6 @@ void test6()
     }
 }
 
-
-#else
-
-void test1() {}
-void test2() {}
-void test3() {}
-void test4() {}
-void test5() {}
-void test6() {}
-
-#endif
-
 int main(int, char**) {
     test1();
     test2();

libcxxabi/test/cxa_call_terminate.pass.cpp

@@ -0,0 +1,34 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+// We're testing the diagnosed behaviour here.
+// ADDITIONAL_COMPILE_FLAGS: -Wno-exceptions
+
+#include <cassert>
+#include <cstdlib>
+#include <exception>
+
+#include "test_macros.h"
+
+void func() TEST_NOEXCEPT {
+  try {
+    throw 1;
+  } catch (float) {
+  }
+}
+
+[[noreturn]] void terminate_handler() {
+  assert(std::current_exception() != nullptr);
+  std::exit(0);
+}
+
+int main(int, char**) {
+  std::set_terminate(terminate_handler);
+  func();
+  assert(false);
+}