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    _LIBCPP_INLINE_VISIBILITY exception(const exception&) _NOEXCEPT = default;
102
103    virtual ~exception() _NOEXCEPT;
104    virtual const char* what() const _NOEXCEPT;
105};
106
107class _LIBCPP_EXCEPTION_ABI bad_exception
108    : public exception
109{
110public:
111    _LIBCPP_INLINE_VISIBILITY bad_exception() _NOEXCEPT {}
112    virtual ~bad_exception() _NOEXCEPT;
113    virtual const char* what() const _NOEXCEPT;
114};
115#endif // !_LIBCPP_ABI_VCRUNTIME
116
117#if _LIBCPP_STD_VER <= 14 \
118    || defined(_LIBCPP_ENABLE_CXX17_REMOVED_UNEXPECTED_FUNCTIONS) \
119    || defined(_LIBCPP_BUILDING_LIBRARY)
120typedef void (*unexpected_handler)();
121_LIBCPP_FUNC_VIS unexpected_handler set_unexpected(unexpected_handler) _NOEXCEPT;
122_LIBCPP_FUNC_VIS unexpected_handler get_unexpected() _NOEXCEPT;
123_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void unexpected();
124#endif
125
126typedef void (*terminate_handler)();
127_LIBCPP_FUNC_VIS terminate_handler set_terminate(terminate_handler) _NOEXCEPT;
128_LIBCPP_FUNC_VIS terminate_handler get_terminate() _NOEXCEPT;
129_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void terminate() _NOEXCEPT;
130
131_LIBCPP_FUNC_VIS bool uncaught_exception() _NOEXCEPT;
132_LIBCPP_FUNC_VIS _LIBCPP_AVAILABILITY_UNCAUGHT_EXCEPTIONS int uncaught_exceptions() _NOEXCEPT;
133
134class _LIBCPP_TYPE_VIS exception_ptr;
135
136_LIBCPP_FUNC_VIS exception_ptr current_exception() _NOEXCEPT;
137_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void rethrow_exception(exception_ptr);
138
139#ifndef _LIBCPP_ABI_MICROSOFT
140
141class _LIBCPP_TYPE_VIS exception_ptr
142{
143    void* __ptr_;
144public:
145    _LIBCPP_INLINE_VISIBILITY exception_ptr() _NOEXCEPT : __ptr_() {}
146    _LIBCPP_INLINE_VISIBILITY exception_ptr(nullptr_t) _NOEXCEPT : __ptr_() {}
147
148    exception_ptr(const exception_ptr&) _NOEXCEPT;
149    exception_ptr& operator=(const exception_ptr&) _NOEXCEPT;
150    ~exception_ptr() _NOEXCEPT;
151
152    _LIBCPP_INLINE_VISIBILITY _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT
153    {return __ptr_ != nullptr;}
154
155    friend _LIBCPP_INLINE_VISIBILITY
156    bool operator==(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT
157        {return __x.__ptr_ == __y.__ptr_;}
158
159    friend _LIBCPP_INLINE_VISIBILITY
160    bool operator!=(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT
161        {return !(__x == __y);}
162
163    friend _LIBCPP_FUNC_VIS exception_ptr current_exception() _NOEXCEPT;
164    friend _LIBCPP_FUNC_VIS void rethrow_exception(exception_ptr);
165};
166
167template<class _Ep>
168_LIBCPP_INLINE_VISIBILITY exception_ptr
169make_exception_ptr(_Ep __e) _NOEXCEPT
170{
171#ifndef _LIBCPP_NO_EXCEPTIONS
172    try
173    {
174        throw __e;
175    }
176    catch (...)
177    {
178        return current_exception();
179    }
180#else
181    ((void)__e);
182    _VSTD::abort();
183#endif
184}
185
186#else // _LIBCPP_ABI_MICROSOFT
187
188class _LIBCPP_TYPE_VIS exception_ptr
189{
190#if defined(__clang__)
191#pragma clang diagnostic push
192#pragma clang diagnostic ignored "-Wunused-private-field"
193#endif
194    void* __ptr1_;
195    void* __ptr2_;
196#if defined(__clang__)
197#pragma clang diagnostic pop
198#endif
199public:
200    exception_ptr() _NOEXCEPT;
201    exception_ptr(nullptr_t) _NOEXCEPT;
202    exception_ptr(const exception_ptr& __other) _NOEXCEPT;
203    exception_ptr& operator=(const exception_ptr& __other) _NOEXCEPT;
204    exception_ptr& operator=(nullptr_t) _NOEXCEPT;
205    ~exception_ptr() _NOEXCEPT;
206    _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT;
207};
208
209_LIBCPP_FUNC_VIS
210bool operator==(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT;
211
212inline _LIBCPP_INLINE_VISIBILITY
213bool operator!=(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT
214    {return !(__x == __y);}
215
216_LIBCPP_FUNC_VIS void swap(exception_ptr&, exception_ptr&) _NOEXCEPT;
217
218_LIBCPP_FUNC_VIS exception_ptr __copy_exception_ptr(void *__except, const void* __ptr);
219_LIBCPP_FUNC_VIS exception_ptr current_exception() _NOEXCEPT;
220_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void rethrow_exception(exception_ptr p);
221
222// This is a built-in template function which automagically extracts the required
223// information.
224template <class _E> void *__GetExceptionInfo(_E);
225
226template<class _Ep>
227_LIBCPP_INLINE_VISIBILITY exception_ptr
228make_exception_ptr(_Ep __e) _NOEXCEPT
229{
230  return __copy_exception_ptr(_VSTD::addressof(__e), __GetExceptionInfo(__e));
231}
232
233#endif // _LIBCPP_ABI_MICROSOFT
234// nested_exception
235
236class _LIBCPP_EXCEPTION_ABI nested_exception
237{
238    exception_ptr __ptr_;
239public:
240    nested_exception() _NOEXCEPT;
241//     nested_exception(const nested_exception&) noexcept = default;
242//     nested_exception& operator=(const nested_exception&) noexcept = default;
243    virtual ~nested_exception() _NOEXCEPT;
244
245    // access functions
246    _LIBCPP_NORETURN void rethrow_nested() const;
247    _LIBCPP_INLINE_VISIBILITY exception_ptr nested_ptr() const _NOEXCEPT {return __ptr_;}
248};
249
250template <class _Tp>
251struct __nested
252    : public _Tp,
253      public nested_exception
254{
255    _LIBCPP_INLINE_VISIBILITY explicit __nested(const _Tp& __t) : _Tp(__t) {}
256};
257
258#ifndef _LIBCPP_NO_EXCEPTIONS
259template <class _Tp, class _Up, bool>
260struct __throw_with_nested;
261
262template <class _Tp, class _Up>
263struct __throw_with_nested<_Tp, _Up, true> {
264    _LIBCPP_NORETURN static inline _LIBCPP_INLINE_VISIBILITY void
265    __do_throw(_Tp&& __t)
266    {
267        throw __nested<_Up>(_VSTD::forward<_Tp>(__t));
268    }
269};
270
271template <class _Tp, class _Up>
272struct __throw_with_nested<_Tp, _Up, false> {
273    _LIBCPP_NORETURN static inline _LIBCPP_INLINE_VISIBILITY void
274#ifndef _LIBCPP_CXX03_LANG
275    __do_throw(_Tp&& __t)
276#else
277    __do_throw (_Tp& __t)
278#endif  // _LIBCPP_CXX03_LANG
279    {
280        throw _VSTD::forward<_Tp>(__t);
281    }
282};
283#endif
284
285template <class _Tp>
286_LIBCPP_NORETURN
287void
288throw_with_nested(_Tp&& __t)
289{
290#ifndef _LIBCPP_NO_EXCEPTIONS
291    typedef typename decay<_Tp>::type _Up;
292    static_assert( is_copy_constructible<_Up>::value, "type thrown must be CopyConstructible");
293    __throw_with_nested<_Tp, _Up,
294        is_class<_Up>::value &&
295        !is_base_of<nested_exception, _Up>::value &&
296        !__libcpp_is_final<_Up>::value>::
297            __do_throw(_VSTD::forward<_Tp>(__t));
298#else
299    ((void)__t);
300    // FIXME: Make this abort
301#endif
302}
303
304template <class _From, class _To>
305struct __can_dynamic_cast : public _LIBCPP_BOOL_CONSTANT(
306              is_polymorphic<_From>::value &&
307                 (!is_base_of<_To, _From>::value ||
308                   is_convertible<const _From*, const _To*>::value)) {};
309
310template <class _Ep>
311inline _LIBCPP_INLINE_VISIBILITY
312void
313rethrow_if_nested(const _Ep& __e,
314                  typename enable_if< __can_dynamic_cast<_Ep, nested_exception>::value>::type* = 0)
315{
316    const nested_exception* __nep = dynamic_cast<const nested_exception*>(_VSTD::addressof(__e));
317    if (__nep)
318        __nep->rethrow_nested();
319}
320
321template <class _Ep>
322inline _LIBCPP_INLINE_VISIBILITY
323void
324rethrow_if_nested(const _Ep&,
325                  typename enable_if<!__can_dynamic_cast<_Ep, nested_exception>::value>::type* = 0)
326{
327}
328
329}  // std
330
331#endif  // _LIBCPP_EXCEPTION
332