xref: /freebsd-src/contrib/llvm-project/libcxx/include/__exception/nested_exception.h (revision 0fca6ea1d4eea4c934cfff25ac9ee8ad6fe95583)
106c3fb27SDimitry Andric //===----------------------------------------------------------------------===//
206c3fb27SDimitry Andric //
306c3fb27SDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
406c3fb27SDimitry Andric // See https://llvm.org/LICENSE.txt for license information.
506c3fb27SDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
606c3fb27SDimitry Andric //
706c3fb27SDimitry Andric //===----------------------------------------------------------------------===//
806c3fb27SDimitry Andric 
906c3fb27SDimitry Andric #ifndef _LIBCPP___EXCEPTION_NESTED_EXCEPTION_H
1006c3fb27SDimitry Andric #define _LIBCPP___EXCEPTION_NESTED_EXCEPTION_H
1106c3fb27SDimitry Andric 
1206c3fb27SDimitry Andric #include <__config>
1306c3fb27SDimitry Andric #include <__exception/exception_ptr.h>
1406c3fb27SDimitry Andric #include <__memory/addressof.h>
1506c3fb27SDimitry Andric #include <__type_traits/decay.h>
1606c3fb27SDimitry Andric #include <__type_traits/is_base_of.h>
1706c3fb27SDimitry Andric #include <__type_traits/is_class.h>
18*0fca6ea1SDimitry Andric #include <__type_traits/is_constructible.h>
1906c3fb27SDimitry Andric #include <__type_traits/is_convertible.h>
2006c3fb27SDimitry Andric #include <__type_traits/is_final.h>
2106c3fb27SDimitry Andric #include <__type_traits/is_polymorphic.h>
2206c3fb27SDimitry Andric #include <__utility/forward.h>
2306c3fb27SDimitry Andric #include <cstddef>
2406c3fb27SDimitry Andric 
2506c3fb27SDimitry Andric #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
2606c3fb27SDimitry Andric #  pragma GCC system_header
2706c3fb27SDimitry Andric #endif
2806c3fb27SDimitry Andric 
2906c3fb27SDimitry Andric namespace std { // purposefully not using versioning namespace
3006c3fb27SDimitry Andric 
3106c3fb27SDimitry Andric class _LIBCPP_EXPORTED_FROM_ABI nested_exception {
3206c3fb27SDimitry Andric   exception_ptr __ptr_;
3306c3fb27SDimitry Andric 
3406c3fb27SDimitry Andric public:
3506c3fb27SDimitry Andric   nested_exception() _NOEXCEPT;
365f757f3fSDimitry Andric   _LIBCPP_HIDE_FROM_ABI nested_exception(const nested_exception&) _NOEXCEPT            = default;
375f757f3fSDimitry Andric   _LIBCPP_HIDE_FROM_ABI nested_exception& operator=(const nested_exception&) _NOEXCEPT = default;
3806c3fb27SDimitry Andric   virtual ~nested_exception() _NOEXCEPT;
3906c3fb27SDimitry Andric 
4006c3fb27SDimitry Andric   // access functions
4106c3fb27SDimitry Andric   _LIBCPP_NORETURN void rethrow_nested() const;
4206c3fb27SDimitry Andric   _LIBCPP_HIDE_FROM_ABI exception_ptr nested_ptr() const _NOEXCEPT { return __ptr_; }
4306c3fb27SDimitry Andric };
4406c3fb27SDimitry Andric 
4506c3fb27SDimitry Andric template <class _Tp>
4606c3fb27SDimitry Andric struct __nested : public _Tp, public nested_exception {
4706c3fb27SDimitry Andric   _LIBCPP_HIDE_FROM_ABI explicit __nested(const _Tp& __t) : _Tp(__t) {}
4806c3fb27SDimitry Andric };
4906c3fb27SDimitry Andric 
5006c3fb27SDimitry Andric #ifndef _LIBCPP_HAS_NO_EXCEPTIONS
5106c3fb27SDimitry Andric template <class _Tp, class _Up, bool>
5206c3fb27SDimitry Andric struct __throw_with_nested;
5306c3fb27SDimitry Andric 
5406c3fb27SDimitry Andric template <class _Tp, class _Up>
5506c3fb27SDimitry Andric struct __throw_with_nested<_Tp, _Up, true> {
565f757f3fSDimitry Andric   _LIBCPP_NORETURN static inline _LIBCPP_HIDE_FROM_ABI void __do_throw(_Tp&& __t) {
5706c3fb27SDimitry Andric     throw __nested<_Up>(std::forward<_Tp>(__t));
5806c3fb27SDimitry Andric   }
5906c3fb27SDimitry Andric };
6006c3fb27SDimitry Andric 
6106c3fb27SDimitry Andric template <class _Tp, class _Up>
6206c3fb27SDimitry Andric struct __throw_with_nested<_Tp, _Up, false> {
635f757f3fSDimitry Andric   _LIBCPP_NORETURN static inline _LIBCPP_HIDE_FROM_ABI void __do_throw(_Tp&& __t) { throw std::forward<_Tp>(__t); }
6406c3fb27SDimitry Andric };
6506c3fb27SDimitry Andric #endif
6606c3fb27SDimitry Andric 
6706c3fb27SDimitry Andric template <class _Tp>
6806c3fb27SDimitry Andric _LIBCPP_NORETURN _LIBCPP_HIDE_FROM_ABI void throw_with_nested(_Tp&& __t) {
6906c3fb27SDimitry Andric #ifndef _LIBCPP_HAS_NO_EXCEPTIONS
7006c3fb27SDimitry Andric   using _Up = __decay_t<_Tp>;
7106c3fb27SDimitry Andric   static_assert(is_copy_constructible<_Up>::value, "type thrown must be CopyConstructible");
7206c3fb27SDimitry Andric   __throw_with_nested<_Tp,
7306c3fb27SDimitry Andric                       _Up,
7406c3fb27SDimitry Andric                       is_class<_Up>::value && !is_base_of<nested_exception, _Up>::value &&
7506c3fb27SDimitry Andric                           !__libcpp_is_final<_Up>::value>::__do_throw(std::forward<_Tp>(__t));
7606c3fb27SDimitry Andric #else
7706c3fb27SDimitry Andric   ((void)__t);
7806c3fb27SDimitry Andric   // FIXME: Make this abort
7906c3fb27SDimitry Andric #endif
8006c3fb27SDimitry Andric }
8106c3fb27SDimitry Andric 
8206c3fb27SDimitry Andric template <class _From, class _To>
8306c3fb27SDimitry Andric struct __can_dynamic_cast
8406c3fb27SDimitry Andric     : _BoolConstant< is_polymorphic<_From>::value &&
8506c3fb27SDimitry Andric                      (!is_base_of<_To, _From>::value || is_convertible<const _From*, const _To*>::value)> {};
8606c3fb27SDimitry Andric 
87*0fca6ea1SDimitry Andric template <class _Ep, __enable_if_t< __can_dynamic_cast<_Ep, nested_exception>::value, int> = 0>
88*0fca6ea1SDimitry Andric inline _LIBCPP_HIDE_FROM_ABI void rethrow_if_nested(const _Ep& __e) {
8906c3fb27SDimitry Andric   const nested_exception* __nep = dynamic_cast<const nested_exception*>(std::addressof(__e));
9006c3fb27SDimitry Andric   if (__nep)
9106c3fb27SDimitry Andric     __nep->rethrow_nested();
9206c3fb27SDimitry Andric }
9306c3fb27SDimitry Andric 
94*0fca6ea1SDimitry Andric template <class _Ep, __enable_if_t<!__can_dynamic_cast<_Ep, nested_exception>::value, int> = 0>
95*0fca6ea1SDimitry Andric inline _LIBCPP_HIDE_FROM_ABI void rethrow_if_nested(const _Ep&) {}
9606c3fb27SDimitry Andric 
9706c3fb27SDimitry Andric } // namespace std
9806c3fb27SDimitry Andric 
9906c3fb27SDimitry Andric #endif // _LIBCPP___EXCEPTION_NESTED_EXCEPTION_H
100