[libcxx-commits] [libcxx] [libc++] fix std::make_exception_ptr interaction with ObjC (PR #135386)

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llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-libcxx

Author: None (itrofimow)

<details>
<summary>Changes</summary>

Clang treats throwing/catching ObjC types differently from C++ types, and omitting the `throw` in `std::make_exception_ptr` breaks ObjC invariants about how types are thrown/caught

---
Full diff: https://github.com/llvm/llvm-project/pull/135386.diff


1 Files Affected:

- (modified) libcxx/include/__exception/exception_ptr.h (+2-1) 


``````````diff
diff --git a/libcxx/include/__exception/exception_ptr.h b/libcxx/include/__exception/exception_ptr.h
index dac5b00b57fe3..167aa4d9b367a 100644
--- a/libcxx/include/__exception/exception_ptr.h
+++ b/libcxx/include/__exception/exception_ptr.h
@@ -92,7 +92,8 @@ class _LIBCPP_EXPORTED_FROM_ABI exception_ptr {
 template <class _Ep>
 _LIBCPP_HIDE_FROM_ABI exception_ptr make_exception_ptr(_Ep __e) _NOEXCEPT {
 #  if _LIBCPP_HAS_EXCEPTIONS
-#    if _LIBCPP_AVAILABILITY_HAS_INIT_PRIMARY_EXCEPTION && __cplusplus >= 201103L
+  // Clang treats throwing ObjC types differently, and we have to preserve original throw-ing behavior
+#    if !defined(__OBJC__) && _LIBCPP_AVAILABILITY_HAS_INIT_PRIMARY_EXCEPTION && __cplusplus >= 201103L
   using _Ep2 = __decay_t<_Ep>;
 
   void* __ex = __cxxabiv1::__cxa_allocate_exception(sizeof(_Ep));

``````````

</details>


https://github.com/llvm/llvm-project/pull/135386