xref: /freebsd/contrib/llvm-project/libcxx/include/__exception/exception_ptr.h (revision 96190b4fef3b4a0cc3ca0606b0c4e3e69a5e6717)
1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #ifndef _LIBCPP___EXCEPTION_EXCEPTION_PTR_H
10 #define _LIBCPP___EXCEPTION_EXCEPTION_PTR_H
11 
12 #include <__availability>
13 #include <__config>
14 #include <__exception/operations.h>
15 #include <__memory/addressof.h>
16 #include <__memory/construct_at.h>
17 #include <__type_traits/decay.h>
18 #include <cstddef>
19 #include <cstdlib>
20 #include <new>
21 #include <typeinfo>
22 
23 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
24 #  pragma GCC system_header
25 #endif
26 
27 #ifndef _LIBCPP_ABI_MICROSOFT
28 
29 namespace __cxxabiv1 {
30 
31 extern "C" {
32 _LIBCPP_OVERRIDABLE_FUNC_VIS void* __cxa_allocate_exception(size_t) throw();
33 _LIBCPP_OVERRIDABLE_FUNC_VIS void __cxa_free_exception(void*) throw();
34 
35 struct __cxa_exception;
36 _LIBCPP_OVERRIDABLE_FUNC_VIS __cxa_exception* __cxa_init_primary_exception(
37     void*,
38     std::type_info*,
39     void(
40 #  if defined(_WIN32)
41         __thiscall
42 #  endif
43             *)(void*)) throw();
44 }
45 
46 } // namespace __cxxabiv1
47 
48 #endif
49 
50 namespace std { // purposefully not using versioning namespace
51 
52 #ifndef _LIBCPP_ABI_MICROSOFT
53 
54 class _LIBCPP_EXPORTED_FROM_ABI exception_ptr {
55   void* __ptr_;
56 
57   static exception_ptr __from_native_exception_pointer(void*) _NOEXCEPT;
58 
59   template <class _Ep>
60   friend _LIBCPP_HIDE_FROM_ABI exception_ptr make_exception_ptr(_Ep) _NOEXCEPT;
61 
62 public:
63   _LIBCPP_HIDE_FROM_ABI exception_ptr() _NOEXCEPT : __ptr_() {}
64   _LIBCPP_HIDE_FROM_ABI exception_ptr(nullptr_t) _NOEXCEPT : __ptr_() {}
65 
66   exception_ptr(const exception_ptr&) _NOEXCEPT;
67   exception_ptr& operator=(const exception_ptr&) _NOEXCEPT;
68   ~exception_ptr() _NOEXCEPT;
69 
70   _LIBCPP_HIDE_FROM_ABI explicit operator bool() const _NOEXCEPT { return __ptr_ != nullptr; }
71 
72   friend _LIBCPP_HIDE_FROM_ABI bool operator==(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT {
73     return __x.__ptr_ == __y.__ptr_;
74   }
75 
76   friend _LIBCPP_HIDE_FROM_ABI bool operator!=(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT {
77     return !(__x == __y);
78   }
79 
80   friend _LIBCPP_EXPORTED_FROM_ABI exception_ptr current_exception() _NOEXCEPT;
81   friend _LIBCPP_EXPORTED_FROM_ABI void rethrow_exception(exception_ptr);
82 };
83 
84 template <class _Ep>
85 _LIBCPP_HIDE_FROM_ABI exception_ptr make_exception_ptr(_Ep __e) _NOEXCEPT {
86 #  ifndef _LIBCPP_HAS_NO_EXCEPTIONS
87 #    if _LIBCPP_AVAILABILITY_HAS_INIT_PRIMARY_EXCEPTION && __cplusplus >= 201103L
88   using _Ep2 = __decay_t<_Ep>;
89 
90   void* __ex = __cxxabiv1::__cxa_allocate_exception(sizeof(_Ep));
91   (void)__cxxabiv1::__cxa_init_primary_exception(__ex, const_cast<std::type_info*>(&typeid(_Ep)), [](void* __p) {
92     std::__destroy_at(static_cast<_Ep2*>(__p));
93   });
94 
95   try {
96     ::new (__ex) _Ep2(__e);
97     return exception_ptr::__from_native_exception_pointer(__ex);
98   } catch (...) {
99     __cxxabiv1::__cxa_free_exception(__ex);
100     return current_exception();
101   }
102 #    else
103   try {
104     throw __e;
105   } catch (...) {
106     return current_exception();
107   }
108 #    endif
109 #  else
110   ((void)__e);
111   std::abort();
112 #  endif
113 }
114 
115 #else // _LIBCPP_ABI_MICROSOFT
116 
117 class _LIBCPP_EXPORTED_FROM_ABI exception_ptr {
118   _LIBCPP_DIAGNOSTIC_PUSH
119   _LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wunused-private-field")
120   void* __ptr1_;
121   void* __ptr2_;
122   _LIBCPP_DIAGNOSTIC_POP
123 
124 public:
125   exception_ptr() _NOEXCEPT;
126   exception_ptr(nullptr_t) _NOEXCEPT;
127   exception_ptr(const exception_ptr& __other) _NOEXCEPT;
128   exception_ptr& operator=(const exception_ptr& __other) _NOEXCEPT;
129   exception_ptr& operator=(nullptr_t) _NOEXCEPT;
130   ~exception_ptr() _NOEXCEPT;
131   explicit operator bool() const _NOEXCEPT;
132 };
133 
134 _LIBCPP_EXPORTED_FROM_ABI bool operator==(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT;
135 
136 inline _LIBCPP_HIDE_FROM_ABI bool operator!=(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT {
137   return !(__x == __y);
138 }
139 
140 _LIBCPP_EXPORTED_FROM_ABI void swap(exception_ptr&, exception_ptr&) _NOEXCEPT;
141 
142 _LIBCPP_EXPORTED_FROM_ABI exception_ptr __copy_exception_ptr(void* __except, const void* __ptr);
143 _LIBCPP_EXPORTED_FROM_ABI exception_ptr current_exception() _NOEXCEPT;
144 _LIBCPP_NORETURN _LIBCPP_EXPORTED_FROM_ABI void rethrow_exception(exception_ptr);
145 
146 // This is a built-in template function which automagically extracts the required
147 // information.
148 template <class _E>
149 void* __GetExceptionInfo(_E);
150 
151 template <class _Ep>
152 _LIBCPP_HIDE_FROM_ABI exception_ptr make_exception_ptr(_Ep __e) _NOEXCEPT {
153   return __copy_exception_ptr(std::addressof(__e), __GetExceptionInfo(__e));
154 }
155 
156 #endif // _LIBCPP_ABI_MICROSOFT
157 } // namespace std
158 
159 #endif // _LIBCPP___EXCEPTION_EXCEPTION_PTR_H
160