xref: /freebsd/contrib/llvm-project/libcxx/include/exception (revision e6bfd18d21b225af6a0ed67ceeaf1293b7b9eba5) 
1// -*- C++ -*-
2//===----------------------------------------------------------------------===//
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 <__assert> // all public C++ headers provide the assertion handler
80#include <__availability>
81#include <__config>
82#include <__memory/addressof.h>
83#include <cstddef>
84#include <cstdlib>
85#include <type_traits>
86#include <version>
87
88#if defined(_LIBCPP_ABI_VCRUNTIME)
89#include <vcruntime_exception.h>
90#endif
91
92#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
93#  pragma GCC system_header
94#endif
95
96namespace std  // purposefully not using versioning namespace
97{
98
99#if !defined(_LIBCPP_ABI_VCRUNTIME)
100class _LIBCPP_EXCEPTION_ABI exception
101{
102public:
103    _LIBCPP_INLINE_VISIBILITY exception() _NOEXCEPT {}
104    _LIBCPP_INLINE_VISIBILITY exception(const exception&) _NOEXCEPT = default;
105
106    virtual ~exception() _NOEXCEPT;
107    virtual const char* what() const _NOEXCEPT;
108};
109
110class _LIBCPP_EXCEPTION_ABI bad_exception
111    : public exception
112{
113public:
114    _LIBCPP_INLINE_VISIBILITY bad_exception() _NOEXCEPT {}
115    virtual ~bad_exception() _NOEXCEPT;
116    virtual const char* what() const _NOEXCEPT;
117};
118#endif // !_LIBCPP_ABI_VCRUNTIME
119
120#if _LIBCPP_STD_VER <= 14 \
121    || defined(_LIBCPP_ENABLE_CXX17_REMOVED_UNEXPECTED_FUNCTIONS) \
122    || defined(_LIBCPP_BUILDING_LIBRARY)
123typedef void (*unexpected_handler)();
124_LIBCPP_FUNC_VIS unexpected_handler set_unexpected(unexpected_handler) _NOEXCEPT;
125_LIBCPP_FUNC_VIS unexpected_handler get_unexpected() _NOEXCEPT;
126_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void unexpected();
127#endif
128
129typedef void (*terminate_handler)();
130_LIBCPP_FUNC_VIS terminate_handler set_terminate(terminate_handler) _NOEXCEPT;
131_LIBCPP_FUNC_VIS terminate_handler get_terminate() _NOEXCEPT;
132_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void terminate() _NOEXCEPT;
133
134_LIBCPP_FUNC_VIS bool uncaught_exception() _NOEXCEPT;
135_LIBCPP_FUNC_VIS _LIBCPP_AVAILABILITY_UNCAUGHT_EXCEPTIONS int uncaught_exceptions() _NOEXCEPT;
136
137class _LIBCPP_TYPE_VIS exception_ptr;
138
139_LIBCPP_FUNC_VIS exception_ptr current_exception() _NOEXCEPT;
140_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void rethrow_exception(exception_ptr);
141
142#ifndef _LIBCPP_ABI_MICROSOFT
143
144class _LIBCPP_TYPE_VIS exception_ptr
145{
146    void* __ptr_;
147public:
148    _LIBCPP_INLINE_VISIBILITY exception_ptr() _NOEXCEPT : __ptr_() {}
149    _LIBCPP_INLINE_VISIBILITY exception_ptr(nullptr_t) _NOEXCEPT : __ptr_() {}
150
151    exception_ptr(const exception_ptr&) _NOEXCEPT;
152    exception_ptr& operator=(const exception_ptr&) _NOEXCEPT;
153    ~exception_ptr() _NOEXCEPT;
154
155    _LIBCPP_INLINE_VISIBILITY explicit operator bool() const _NOEXCEPT
156    {return __ptr_ != nullptr;}
157
158    friend _LIBCPP_INLINE_VISIBILITY
159    bool operator==(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT
160        {return __x.__ptr_ == __y.__ptr_;}
161
162    friend _LIBCPP_INLINE_VISIBILITY
163    bool operator!=(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT
164        {return !(__x == __y);}
165
166    friend _LIBCPP_FUNC_VIS exception_ptr current_exception() _NOEXCEPT;
167    friend _LIBCPP_FUNC_VIS void rethrow_exception(exception_ptr);
168};
169
170template<class _Ep>
171_LIBCPP_INLINE_VISIBILITY exception_ptr
172make_exception_ptr(_Ep __e) _NOEXCEPT
173{
174#ifndef _LIBCPP_NO_EXCEPTIONS
175    try
176    {
177        throw __e;
178    }
179    catch (...)
180    {
181        return current_exception();
182    }
183#else
184    ((void)__e);
185    _VSTD::abort();
186#endif
187}
188
189#else // _LIBCPP_ABI_MICROSOFT
190
191class _LIBCPP_TYPE_VIS exception_ptr
192{
193_LIBCPP_DIAGNOSTIC_PUSH
194_LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wunused-private-field")
195    void* __ptr1_;
196    void* __ptr2_;
197_LIBCPP_DIAGNOSTIC_POP
198public:
199    exception_ptr() _NOEXCEPT;
200    exception_ptr(nullptr_t) _NOEXCEPT;
201    exception_ptr(const exception_ptr& __other) _NOEXCEPT;
202    exception_ptr& operator=(const exception_ptr& __other) _NOEXCEPT;
203    exception_ptr& operator=(nullptr_t) _NOEXCEPT;
204    ~exception_ptr() _NOEXCEPT;
205    explicit operator bool() const _NOEXCEPT;
206};
207
208_LIBCPP_FUNC_VIS
209bool operator==(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT;
210
211inline _LIBCPP_INLINE_VISIBILITY
212bool operator!=(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT
213    {return !(__x == __y);}
214
215_LIBCPP_FUNC_VIS void swap(exception_ptr&, exception_ptr&) _NOEXCEPT;
216
217_LIBCPP_FUNC_VIS exception_ptr __copy_exception_ptr(void *__except, const void* __ptr);
218_LIBCPP_FUNC_VIS exception_ptr current_exception() _NOEXCEPT;
219_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void rethrow_exception(exception_ptr);
220
221// This is a built-in template function which automagically extracts the required
222// information.
223template <class _E> void *__GetExceptionInfo(_E);
224
225template<class _Ep>
226_LIBCPP_INLINE_VISIBILITY exception_ptr
227make_exception_ptr(_Ep __e) _NOEXCEPT
228{
229  return __copy_exception_ptr(_VSTD::addressof(__e), __GetExceptionInfo(__e));
230}
231
232#endif // _LIBCPP_ABI_MICROSOFT
233// nested_exception
234
235class _LIBCPP_EXCEPTION_ABI nested_exception
236{
237    exception_ptr __ptr_;
238public:
239    nested_exception() _NOEXCEPT;
240//     nested_exception(const nested_exception&) noexcept = default;
241//     nested_exception& operator=(const nested_exception&) noexcept = default;
242    virtual ~nested_exception() _NOEXCEPT;
243
244    // access functions
245    _LIBCPP_NORETURN void rethrow_nested() const;
246    _LIBCPP_INLINE_VISIBILITY exception_ptr nested_ptr() const _NOEXCEPT {return __ptr_;}
247};
248
249template <class _Tp>
250struct __nested
251    : public _Tp,
252      public nested_exception
253{
254    _LIBCPP_INLINE_VISIBILITY explicit __nested(const _Tp& __t) : _Tp(__t) {}
255};
256
257#ifndef _LIBCPP_NO_EXCEPTIONS
258template <class _Tp, class _Up, bool>
259struct __throw_with_nested;
260
261template <class _Tp, class _Up>
262struct __throw_with_nested<_Tp, _Up, true> {
263    _LIBCPP_NORETURN static inline _LIBCPP_INLINE_VISIBILITY void
264    __do_throw(_Tp&& __t)
265    {
266        throw __nested<_Up>(static_cast<_Tp&&>(__t));
267    }
268};
269
270template <class _Tp, class _Up>
271struct __throw_with_nested<_Tp, _Up, false> {
272    _LIBCPP_NORETURN static inline _LIBCPP_INLINE_VISIBILITY void
273#ifndef _LIBCPP_CXX03_LANG
274    __do_throw(_Tp&& __t)
275#else
276    __do_throw (_Tp& __t)
277#endif // _LIBCPP_CXX03_LANG
278    {
279        throw static_cast<_Tp&&>(__t);
280    }
281};
282#endif
283
284template <class _Tp>
285_LIBCPP_NORETURN
286void
287throw_with_nested(_Tp&& __t)
288{
289#ifndef _LIBCPP_NO_EXCEPTIONS
290    typedef typename decay<_Tp>::type _Up;
291    static_assert( is_copy_constructible<_Up>::value, "type thrown must be CopyConstructible");
292    __throw_with_nested<_Tp, _Up,
293        is_class<_Up>::value &&
294        !is_base_of<nested_exception, _Up>::value &&
295        !__libcpp_is_final<_Up>::value>::
296            __do_throw(static_cast<_Tp&&>(__t));
297#else
298    ((void)__t);
299    // FIXME: Make this abort
300#endif
301}
302
303template <class _From, class _To>
304struct __can_dynamic_cast : _BoolConstant<
305              is_polymorphic<_From>::value &&
306                 (!is_base_of<_To, _From>::value ||
307                   is_convertible<const _From*, const _To*>::value)> {};
308
309template <class _Ep>
310inline _LIBCPP_INLINE_VISIBILITY
311void
312rethrow_if_nested(const _Ep& __e,
313                  __enable_if_t< __can_dynamic_cast<_Ep, nested_exception>::value>* = 0)
314{
315    const nested_exception* __nep = dynamic_cast<const nested_exception*>(_VSTD::addressof(__e));
316    if (__nep)
317        __nep->rethrow_nested();
318}
319
320template <class _Ep>
321inline _LIBCPP_INLINE_VISIBILITY
322void
323rethrow_if_nested(const _Ep&,
324                  __enable_if_t<!__can_dynamic_cast<_Ep, nested_exception>::value>* = 0)
325{
326}
327
328} // namespace std
329
330#endif // _LIBCPP_EXCEPTION
331