[libcxx-commits] [libcxxabi] [libc++] [libc++abi] Initialize exception directly in make_exception_ptr if __cxa_init_primary_exception is available in ABI-library (PR #65534)

[via libcxx-commits]

================
@@ -50,15 +67,38 @@ class _LIBCPP_EXPORTED_FROM_ABI exception_ptr {
 
 template <class _Ep>
 _LIBCPP_HIDE_FROM_ABI exception_ptr make_exception_ptr(_Ep __e) _NOEXCEPT {
-#  ifndef _LIBCPP_HAS_NO_EXCEPTIONS
+#  if defined(_LIBCPP_EXCEPTION_PTR_DIRECT_INIT)
+  using _Ep2 = __decay_t<_Ep>;
+  void* __ex = exception_ptr::__init_native_exception(
+      sizeof(_Ep), const_cast<std::type_info*>(&typeid(_Ep)), exception_ptr::__dest_thunk<_Ep2>);
+  // This could happen with older versions of libcxxrt/libcxxabi,
+  // which don't yet support direct exception initialization.
+  if (__ex == nullptr) {
+    try {
+      throw __e;
+    } catch (...) {
+      return current_exception();
+    }
+  }
----------------
EricWF wrote:

We should have an unreachable annotation at the bottom of this block.


https://github.com/llvm/llvm-project/pull/65534