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 <__config>
13 #include <__exception/operations.h>
14 #include <__memory/addressof.h>
15 #include <__memory/construct_at.h>
16 #include <__type_traits/decay.h>
17 #include <cstddef>
18 #include <cstdlib>
19 #include <new>
20 #include <typeinfo>
21
22 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
23 # pragma GCC system_header
24 #endif
25
26 #ifndef _LIBCPP_ABI_MICROSOFT
27
28 # if _LIBCPP_AVAILABILITY_HAS_INIT_PRIMARY_EXCEPTION
29
30 namespace __cxxabiv1 {
31
32 extern "C" {
33 _LIBCPP_OVERRIDABLE_FUNC_VIS void* __cxa_allocate_exception(size_t) throw();
34 _LIBCPP_OVERRIDABLE_FUNC_VIS void __cxa_free_exception(void*) throw();
35
36 struct __cxa_exception;
37 _LIBCPP_OVERRIDABLE_FUNC_VIS __cxa_exception* __cxa_init_primary_exception(
38 void*,
39 std::type_info*,
40 # if defined(_WIN32)
41 void(__thiscall*)(void*)) throw();
42 # elif defined(__wasm__)
43 // In Wasm, a destructor returns its argument
44 void* (*)(void*)) throw();
45 # else
46 void (*)(void*)) throw();
47 # endif
48 }
49
50 } // namespace __cxxabiv1
51
52 # endif
53
54 #endif
55
56 namespace std { // purposefully not using versioning namespace
57
58 #ifndef _LIBCPP_ABI_MICROSOFT
59
60 class _LIBCPP_EXPORTED_FROM_ABI exception_ptr {
61 void* __ptr_;
62
63 static exception_ptr __from_native_exception_pointer(void*) _NOEXCEPT;
64
65 template <class _Ep>
66 friend _LIBCPP_HIDE_FROM_ABI exception_ptr make_exception_ptr(_Ep) _NOEXCEPT;
67
68 public:
69 // exception_ptr is basically a COW string.
70 using __trivially_relocatable = exception_ptr;
71
exception_ptr()72 _LIBCPP_HIDE_FROM_ABI exception_ptr() _NOEXCEPT : __ptr_() {}
exception_ptr(nullptr_t)73 _LIBCPP_HIDE_FROM_ABI exception_ptr(nullptr_t) _NOEXCEPT : __ptr_() {}
74
75 exception_ptr(const exception_ptr&) _NOEXCEPT;
76 exception_ptr& operator=(const exception_ptr&) _NOEXCEPT;
77 ~exception_ptr() _NOEXCEPT;
78
79 _LIBCPP_HIDE_FROM_ABI explicit operator bool() const _NOEXCEPT { return __ptr_ != nullptr; }
80
81 friend _LIBCPP_HIDE_FROM_ABI bool operator==(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT {
82 return __x.__ptr_ == __y.__ptr_;
83 }
84
85 friend _LIBCPP_HIDE_FROM_ABI bool operator!=(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT {
86 return !(__x == __y);
87 }
88
89 friend _LIBCPP_EXPORTED_FROM_ABI exception_ptr current_exception() _NOEXCEPT;
90 friend _LIBCPP_EXPORTED_FROM_ABI void rethrow_exception(exception_ptr);
91 };
92
93 template <class _Ep>
make_exception_ptr(_Ep __e)94 _LIBCPP_HIDE_FROM_ABI exception_ptr make_exception_ptr(_Ep __e) _NOEXCEPT {
95 # ifndef _LIBCPP_HAS_NO_EXCEPTIONS
96 # if _LIBCPP_AVAILABILITY_HAS_INIT_PRIMARY_EXCEPTION && __cplusplus >= 201103L
97 using _Ep2 = __decay_t<_Ep>;
98
99 void* __ex = __cxxabiv1::__cxa_allocate_exception(sizeof(_Ep));
100 # ifdef __wasm__
101 // In Wasm, a destructor returns its argument
102 (void)__cxxabiv1::__cxa_init_primary_exception(
103 __ex, const_cast<std::type_info*>(&typeid(_Ep)), [](void* __p) -> void* {
104 # else
105 (void)__cxxabiv1::__cxa_init_primary_exception(__ex, const_cast<std::type_info*>(&typeid(_Ep)), [](void* __p) {
106 # endif
107 std::__destroy_at(static_cast<_Ep2*>(__p));
108 # ifdef __wasm__
109 return __p;
110 # endif
111 });
112
113 try {
114 ::new (__ex) _Ep2(__e);
115 return exception_ptr::__from_native_exception_pointer(__ex);
116 } catch (...) {
117 __cxxabiv1::__cxa_free_exception(__ex);
118 return current_exception();
119 }
120 # else
121 try {
122 throw __e;
123 } catch (...) {
124 return current_exception();
125 }
126 # endif
127 # else
128 ((void)__e);
129 std::abort();
130 # endif
131 }
132
133 #else // _LIBCPP_ABI_MICROSOFT
134
135 class _LIBCPP_EXPORTED_FROM_ABI exception_ptr {
136 _LIBCPP_DIAGNOSTIC_PUSH
137 _LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wunused-private-field")
138 void* __ptr1_;
139 void* __ptr2_;
140 _LIBCPP_DIAGNOSTIC_POP
141
142 public:
143 exception_ptr() _NOEXCEPT;
144 exception_ptr(nullptr_t) _NOEXCEPT;
145 exception_ptr(const exception_ptr& __other) _NOEXCEPT;
146 exception_ptr& operator=(const exception_ptr& __other) _NOEXCEPT;
147 exception_ptr& operator=(nullptr_t) _NOEXCEPT;
148 ~exception_ptr() _NOEXCEPT;
149 explicit operator bool() const _NOEXCEPT;
150 };
151
152 _LIBCPP_EXPORTED_FROM_ABI bool operator==(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT;
153
154 inline _LIBCPP_HIDE_FROM_ABI bool operator!=(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT {
155 return !(__x == __y);
156 }
157
158 _LIBCPP_EXPORTED_FROM_ABI void swap(exception_ptr&, exception_ptr&) _NOEXCEPT;
159
160 _LIBCPP_EXPORTED_FROM_ABI exception_ptr __copy_exception_ptr(void* __except, const void* __ptr);
161 _LIBCPP_EXPORTED_FROM_ABI exception_ptr current_exception() _NOEXCEPT;
162 _LIBCPP_NORETURN _LIBCPP_EXPORTED_FROM_ABI void rethrow_exception(exception_ptr);
163
164 // This is a built-in template function which automagically extracts the required
165 // information.
166 template <class _E>
167 void* __GetExceptionInfo(_E);
168
169 template <class _Ep>
170 _LIBCPP_HIDE_FROM_ABI exception_ptr make_exception_ptr(_Ep __e) _NOEXCEPT {
171 return __copy_exception_ptr(std::addressof(__e), __GetExceptionInfo(__e));
172 }
173
174 #endif // _LIBCPP_ABI_MICROSOFT
175 } // namespace std
176
177 #endif // _LIBCPP___EXCEPTION_EXCEPTION_PTR_H
178