1// -*- C++ -*-
2//===-------------------------- exception ---------------------------------===//
3//
4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5// See https://llvm.org/LICENSE.txt for license information.
6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef _LIBCPP_EXCEPTION
11#define _LIBCPP_EXCEPTION
12
13/*
14 exception synopsis
15
16namespace std
17{
18
19class exception
20{
21public:
22 exception() noexcept;
23 exception(const exception&) noexcept;
24 exception& operator=(const exception&) noexcept;
25 virtual ~exception() noexcept;
26 virtual const char* what() const noexcept;
27};
28
29class bad_exception
30 : public exception
31{
32public:
33 bad_exception() noexcept;
34 bad_exception(const bad_exception&) noexcept;
35 bad_exception& operator=(const bad_exception&) noexcept;
36 virtual ~bad_exception() noexcept;
37 virtual const char* what() const noexcept;
38};
39
40typedef void (*unexpected_handler)();
41unexpected_handler set_unexpected(unexpected_handler f ) noexcept;
42unexpected_handler get_unexpected() noexcept;
43[[noreturn]] void unexpected();
44
45typedef void (*terminate_handler)();
46terminate_handler set_terminate(terminate_handler f ) noexcept;
47terminate_handler get_terminate() noexcept;
48[[noreturn]] void terminate() noexcept;
49
50bool uncaught_exception() noexcept;
51int uncaught_exceptions() noexcept; // C++17
52
53typedef unspecified exception_ptr;
54
55exception_ptr current_exception() noexcept;
56void rethrow_exception [[noreturn]] (exception_ptr p);
57template<class E> exception_ptr make_exception_ptr(E e) noexcept;
58
59class nested_exception
60{
61public:
62 nested_exception() noexcept;
63 nested_exception(const nested_exception&) noexcept = default;
64 nested_exception& operator=(const nested_exception&) noexcept = default;
65 virtual ~nested_exception() = default;
66
67 // access functions
68 [[noreturn]] void rethrow_nested() const;
69 exception_ptr nested_ptr() const noexcept;
70};
71
72template <class T> [[noreturn]] void throw_with_nested(T&& t);
73template <class E> void rethrow_if_nested(const E& e);
74
75} // std
76
77*/
78
79#include <__config>
80#include <cstddef>
81#include <cstdlib>
82#include <type_traits>
83#include <version>
84
85#if defined(_LIBCPP_ABI_VCRUNTIME)
86#include <vcruntime_exception.h>
87#endif
88
89#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
90#pragma GCC system_header
91#endif
92
93namespace std // purposefully not using versioning namespace
94{
95
96#if !defined(_LIBCPP_ABI_VCRUNTIME)
97class _LIBCPP_EXCEPTION_ABI exception
98{
99public:
100 _LIBCPP_INLINE_VISIBILITY exception() _NOEXCEPT {}
101 virtual ~exception() _NOEXCEPT;
102 virtual const char* what() const _NOEXCEPT;
103};
104
105class _LIBCPP_EXCEPTION_ABI bad_exception
106 : public exception
107{
108public:
109 _LIBCPP_INLINE_VISIBILITY bad_exception() _NOEXCEPT {}
110 virtual ~bad_exception() _NOEXCEPT;
111 virtual const char* what() const _NOEXCEPT;
112};
113#endif // !_LIBCPP_ABI_VCRUNTIME
114
115#if _LIBCPP_STD_VER <= 14 \
116 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_UNEXPECTED_FUNCTIONS) \
117 || defined(_LIBCPP_BUILDING_LIBRARY)
118typedef void (*unexpected_handler)();
119_LIBCPP_FUNC_VIS unexpected_handler set_unexpected(unexpected_handler) _NOEXCEPT;
120_LIBCPP_FUNC_VIS unexpected_handler get_unexpected() _NOEXCEPT;
121_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void unexpected();
122#endif
123
124typedef void (*terminate_handler)();
125_LIBCPP_FUNC_VIS terminate_handler set_terminate(terminate_handler) _NOEXCEPT;
126_LIBCPP_FUNC_VIS terminate_handler get_terminate() _NOEXCEPT;
127_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void terminate() _NOEXCEPT;
128
129_LIBCPP_FUNC_VIS bool uncaught_exception() _NOEXCEPT;
130_LIBCPP_FUNC_VIS _LIBCPP_AVAILABILITY_UNCAUGHT_EXCEPTIONS int uncaught_exceptions() _NOEXCEPT;
131
132class _LIBCPP_TYPE_VIS exception_ptr;
133
134_LIBCPP_FUNC_VIS exception_ptr current_exception() _NOEXCEPT;
135_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void rethrow_exception(exception_ptr);
136
137#ifndef _LIBCPP_ABI_MICROSOFT
138
139class _LIBCPP_TYPE_VIS exception_ptr
140{
141 void* __ptr_;
142public:
143 _LIBCPP_INLINE_VISIBILITY exception_ptr() _NOEXCEPT : __ptr_() {}
144 _LIBCPP_INLINE_VISIBILITY exception_ptr(nullptr_t) _NOEXCEPT : __ptr_() {}
145
146 exception_ptr(const exception_ptr&) _NOEXCEPT;
147 exception_ptr& operator=(const exception_ptr&) _NOEXCEPT;
148 ~exception_ptr() _NOEXCEPT;
149
150 _LIBCPP_INLINE_VISIBILITY _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT
151 {return __ptr_ != nullptr;}
152
153 friend _LIBCPP_INLINE_VISIBILITY
154 bool operator==(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT
155 {return __x.__ptr_ == __y.__ptr_;}
156
157 friend _LIBCPP_INLINE_VISIBILITY
158 bool operator!=(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT
159 {return !(__x == __y);}
160
161 friend _LIBCPP_FUNC_VIS exception_ptr current_exception() _NOEXCEPT;
162 friend _LIBCPP_FUNC_VIS void rethrow_exception(exception_ptr);
163};
164
165template<class _Ep>
166_LIBCPP_INLINE_VISIBILITY exception_ptr
167make_exception_ptr(_Ep __e) _NOEXCEPT
168{
169#ifndef _LIBCPP_NO_EXCEPTIONS
170 try
171 {
172 throw __e;
173 }
174 catch (...)
175 {
176 return current_exception();
177 }
178#else
179 ((void)__e);
180 _VSTD::abort();
181#endif
182}
183
184#else // _LIBCPP_ABI_MICROSOFT
185
186class _LIBCPP_TYPE_VIS exception_ptr
187{
188#if defined(__clang__)
189#pragma clang diagnostic push
190#pragma clang diagnostic ignored "-Wunused-private-field"
191#endif
192 void* __ptr1_;
193 void* __ptr2_;
194#if defined(__clang__)
195#pragma clang diagnostic pop
196#endif
197public:
198 exception_ptr() _NOEXCEPT;
199 exception_ptr(nullptr_t) _NOEXCEPT;
200 exception_ptr(const exception_ptr& __other) _NOEXCEPT;
201 exception_ptr& operator=(const exception_ptr& __other) _NOEXCEPT;
202 exception_ptr& operator=(nullptr_t) _NOEXCEPT;
203 ~exception_ptr() _NOEXCEPT;
204 _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT;
205};
206
207_LIBCPP_FUNC_VIS
208bool operator==(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT;
209
210inline _LIBCPP_INLINE_VISIBILITY
211bool operator!=(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT
212 {return !(__x == __y);}
213
214_LIBCPP_FUNC_VIS void swap(exception_ptr&, exception_ptr&) _NOEXCEPT;
215
216_LIBCPP_FUNC_VIS exception_ptr __copy_exception_ptr(void *__except, const void* __ptr);
217_LIBCPP_FUNC_VIS exception_ptr current_exception() _NOEXCEPT;
218_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void rethrow_exception(exception_ptr p);
219
220// This is a built-in template function which automagically extracts the required
221// information.
222template <class _E> void *__GetExceptionInfo(_E);
223
224template<class _Ep>
225_LIBCPP_INLINE_VISIBILITY exception_ptr
226make_exception_ptr(_Ep __e) _NOEXCEPT
227{
228 return __copy_exception_ptr(_VSTD::addressof(__e), __GetExceptionInfo(__e));
229}
230
231#endif // _LIBCPP_ABI_MICROSOFT
232// nested_exception
233
234class _LIBCPP_EXCEPTION_ABI nested_exception
235{
236 exception_ptr __ptr_;
237public:
238 nested_exception() _NOEXCEPT;
239// nested_exception(const nested_exception&) noexcept = default;
240// nested_exception& operator=(const nested_exception&) noexcept = default;
241 virtual ~nested_exception() _NOEXCEPT;
242
243 // access functions
244 _LIBCPP_NORETURN void rethrow_nested() const;
245 _LIBCPP_INLINE_VISIBILITY exception_ptr nested_ptr() const _NOEXCEPT {return __ptr_;}
246};
247
248template <class _Tp>
249struct __nested
250 : public _Tp,
251 public nested_exception
252{
253 _LIBCPP_INLINE_VISIBILITY explicit __nested(const _Tp& __t) : _Tp(__t) {}
254};
255
256#ifndef _LIBCPP_NO_EXCEPTIONS
257template <class _Tp, class _Up, bool>
258struct __throw_with_nested;
259
260template <class _Tp, class _Up>
261struct __throw_with_nested<_Tp, _Up, true> {
262 _LIBCPP_NORETURN static inline _LIBCPP_INLINE_VISIBILITY void
263 __do_throw(_Tp&& __t)
264 {
265 throw __nested<_Up>(_VSTD::forward<_Tp>(__t));
266 }
267};
268
269template <class _Tp, class _Up>
270struct __throw_with_nested<_Tp, _Up, false> {
271 _LIBCPP_NORETURN static inline _LIBCPP_INLINE_VISIBILITY void
272#ifndef _LIBCPP_CXX03_LANG
273 __do_throw(_Tp&& __t)
274#else
275 __do_throw (_Tp& __t)
276#endif // _LIBCPP_CXX03_LANG
277 {
278 throw _VSTD::forward<_Tp>(__t);
279 }
280};
281#endif
282
283template <class _Tp>
284_LIBCPP_NORETURN
285void
286throw_with_nested(_Tp&& __t)
287{
288#ifndef _LIBCPP_NO_EXCEPTIONS
289 typedef typename decay<_Tp>::type _Up;
290 static_assert( is_copy_constructible<_Up>::value, "type thrown must be CopyConstructible");
291 __throw_with_nested<_Tp, _Up,
292 is_class<_Up>::value &&
293 !is_base_of<nested_exception, _Up>::value &&
294 !__libcpp_is_final<_Up>::value>::
295 __do_throw(_VSTD::forward<_Tp>(__t));
296#else
297 ((void)__t);
298 // FIXME: Make this abort
299#endif
300}
301
302template <class _From, class _To>
303struct __can_dynamic_cast : public _LIBCPP_BOOL_CONSTANT(
304 is_polymorphic<_From>::value &&
305 (!is_base_of<_To, _From>::value ||
306 is_convertible<const _From*, const _To*>::value)) {};
307
308template <class _Ep>
309inline _LIBCPP_INLINE_VISIBILITY
310void
311rethrow_if_nested(const _Ep& __e,
312 typename enable_if< __can_dynamic_cast<_Ep, nested_exception>::value>::type* = 0)
313{
314 const nested_exception* __nep = dynamic_cast<const nested_exception*>(_VSTD::addressof(__e));
315 if (__nep)
316 __nep->rethrow_nested();
317}
318
319template <class _Ep>
320inline _LIBCPP_INLINE_VISIBILITY
321void
322rethrow_if_nested(const _Ep&,
323 typename enable_if<!__can_dynamic_cast<_Ep, nested_exception>::value>::type* = 0)
324{
325}
326
327} // std
328
329#endif // _LIBCPP_EXCEPTION
330