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1// -*- C++ -*-
2//===-------------------------- exception ---------------------------------===//
3//
4//                     The LLVM Compiler Infrastructure
5//
6// This file is dual licensed under the MIT and the University of Illinois Open
7// Source Licenses. See LICENSE.TXT for details.
8//
9//===----------------------------------------------------------------------===//
10
11#ifndef _LIBCPP_EXCEPTION
12#define _LIBCPP_EXCEPTION
13
14/*
15    exception synopsis
16
17namespace std
18{
19
20class exception
21{
22public:
23    exception() noexcept;
24    exception(const exception&) noexcept;
25    exception& operator=(const exception&) noexcept;
26    virtual ~exception() noexcept;
27    virtual const char* what() const noexcept;
28};
29
30class bad_exception
31    : public exception
32{
33public:
34    bad_exception() noexcept;
35    bad_exception(const bad_exception&) noexcept;
36    bad_exception& operator=(const bad_exception&) noexcept;
37    virtual ~bad_exception() noexcept;
38    virtual const char* what() const noexcept;
39};
40
41typedef void (*unexpected_handler)();
42unexpected_handler set_unexpected(unexpected_handler  f ) noexcept;
43unexpected_handler get_unexpected() noexcept;
44[[noreturn]] void unexpected();
45
46typedef void (*terminate_handler)();
47terminate_handler set_terminate(terminate_handler  f ) noexcept;
48terminate_handler get_terminate() noexcept;
49[[noreturn]] void terminate() noexcept;
50
51bool uncaught_exception()  noexcept;
52int  uncaught_exceptions() noexcept;  // C++17
53
54typedef unspecified exception_ptr;
55
56exception_ptr current_exception() noexcept;
57void rethrow_exception [[noreturn]] (exception_ptr p);
58template<class E> exception_ptr make_exception_ptr(E e) noexcept;
59
60class nested_exception
61{
62public:
63    nested_exception() noexcept;
64    nested_exception(const nested_exception&) noexcept = default;
65    nested_exception& operator=(const nested_exception&) noexcept = default;
66    virtual ~nested_exception() = default;
67
68    // access functions
69    [[noreturn]] void rethrow_nested() const;
70    exception_ptr nested_ptr() const noexcept;
71};
72
73template <class T> [[noreturn]] void throw_with_nested(T&& t);
74template <class E> void rethrow_if_nested(const E& e);
75
76}  // std
77
78*/
79
80#include <__config>
81#include <cstddef>
82#include <cstdlib>
83#include <type_traits>
84#include <version>
85
86#if defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_NO_VCRUNTIME)
87#include <vcruntime_exception.h>
88#endif
89
90#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
91#pragma GCC system_header
92#endif
93
94namespace std  // purposefully not using versioning namespace
95{
96
97#if !defined(_LIBCPP_ABI_MICROSOFT) || defined(_LIBCPP_NO_VCRUNTIME)
98class _LIBCPP_EXCEPTION_ABI exception
99{
100public:
101    _LIBCPP_INLINE_VISIBILITY exception() _NOEXCEPT {}
102    virtual ~exception() _NOEXCEPT;
103    virtual const char* what() const _NOEXCEPT;
104};
105
106class _LIBCPP_EXCEPTION_ABI bad_exception
107    : public exception
108{
109public:
110    _LIBCPP_INLINE_VISIBILITY bad_exception() _NOEXCEPT {}
111    virtual ~bad_exception() _NOEXCEPT;
112    virtual const char* what() const _NOEXCEPT;
113};
114#endif // !_LIBCPP_ABI_MICROSOFT || _LIBCPP_NO_VCRUNTIME
115
116#if _LIBCPP_STD_VER <= 14 \
117    || defined(_LIBCPP_ENABLE_CXX17_REMOVED_UNEXPECTED_FUNCTIONS) \
118    || defined(_LIBCPP_BUILDING_LIBRARY)
119typedef void (*unexpected_handler)();
120_LIBCPP_FUNC_VIS unexpected_handler set_unexpected(unexpected_handler) _NOEXCEPT;
121_LIBCPP_FUNC_VIS unexpected_handler get_unexpected() _NOEXCEPT;
122_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void unexpected();
123#endif
124
125typedef void (*terminate_handler)();
126_LIBCPP_FUNC_VIS terminate_handler set_terminate(terminate_handler) _NOEXCEPT;
127_LIBCPP_FUNC_VIS terminate_handler get_terminate() _NOEXCEPT;
128_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void terminate() _NOEXCEPT;
129
130_LIBCPP_FUNC_VIS bool uncaught_exception() _NOEXCEPT;
131_LIBCPP_FUNC_VIS _LIBCPP_AVAILABILITY_UNCAUGHT_EXCEPTIONS int uncaught_exceptions() _NOEXCEPT;
132
133class _LIBCPP_TYPE_VIS exception_ptr;
134
135_LIBCPP_FUNC_VIS exception_ptr current_exception() _NOEXCEPT;
136_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void rethrow_exception(exception_ptr);
137
138#ifndef _LIBCPP_ABI_MICROSOFT
139
140class _LIBCPP_TYPE_VIS exception_ptr
141{
142    void* __ptr_;
143public:
144    _LIBCPP_INLINE_VISIBILITY exception_ptr() _NOEXCEPT : __ptr_() {}
145    _LIBCPP_INLINE_VISIBILITY exception_ptr(nullptr_t) _NOEXCEPT : __ptr_() {}
146
147    exception_ptr(const exception_ptr&) _NOEXCEPT;
148    exception_ptr& operator=(const exception_ptr&) _NOEXCEPT;
149    ~exception_ptr() _NOEXCEPT;
150
151    _LIBCPP_INLINE_VISIBILITY _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT
152    {return __ptr_ != nullptr;}
153
154    friend _LIBCPP_INLINE_VISIBILITY
155    bool operator==(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT
156        {return __x.__ptr_ == __y.__ptr_;}
157
158    friend _LIBCPP_INLINE_VISIBILITY
159    bool operator!=(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT
160        {return !(__x == __y);}
161
162    friend _LIBCPP_FUNC_VIS exception_ptr current_exception() _NOEXCEPT;
163    friend _LIBCPP_FUNC_VIS void rethrow_exception(exception_ptr);
164};
165
166template<class _Ep>
167_LIBCPP_INLINE_VISIBILITY exception_ptr
168make_exception_ptr(_Ep __e) _NOEXCEPT
169{
170#ifndef _LIBCPP_NO_EXCEPTIONS
171    try
172    {
173        throw __e;
174    }
175    catch (...)
176    {
177        return current_exception();
178    }
179#else
180    ((void)__e);
181    _VSTD::abort();
182#endif
183}
184
185#else // _LIBCPP_ABI_MICROSOFT
186
187class _LIBCPP_TYPE_VIS exception_ptr
188{
189#if defined(__clang__)
190#pragma clang diagnostic push
191#pragma clang diagnostic ignored "-Wunused-private-field"
192#endif
193    void* __ptr1_;
194    void* __ptr2_;
195#if defined(__clang__)
196#pragma clang diagnostic pop
197#endif
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    _LIBCPP_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 p);
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#ifndef _LIBCPP_CXX03_LANG
265    __do_throw(_Tp&& __t)
266#else
267    __do_throw (_Tp& __t)
268#endif  // _LIBCPP_CXX03_LANG
269    {
270        throw __nested<_Up>(_VSTD::forward<_Tp>(__t));
271    }
272};
273
274template <class _Tp, class _Up>
275struct __throw_with_nested<_Tp, _Up, false> {
276    _LIBCPP_NORETURN static inline _LIBCPP_INLINE_VISIBILITY void
277#ifndef _LIBCPP_CXX03_LANG
278    __do_throw(_Tp&& __t)
279#else
280    __do_throw (_Tp& __t)
281#endif  // _LIBCPP_CXX03_LANG
282    {
283        throw _VSTD::forward<_Tp>(__t);
284    }
285};
286#endif
287
288template <class _Tp>
289_LIBCPP_NORETURN
290void
291#ifndef _LIBCPP_CXX03_LANG
292throw_with_nested(_Tp&& __t)
293#else
294throw_with_nested (_Tp& __t)
295#endif // _LIBCPP_CXX03_LANG
296{
297#ifndef _LIBCPP_NO_EXCEPTIONS
298    typedef typename decay<_Tp>::type _Up;
299    static_assert( is_copy_constructible<_Up>::value, "type thrown must be CopyConstructible");
300    __throw_with_nested<_Tp, _Up,
301        is_class<_Up>::value &&
302        !is_base_of<nested_exception, _Up>::value &&
303        !__libcpp_is_final<_Up>::value>::
304            __do_throw(_VSTD::forward<_Tp>(__t));
305#else
306    ((void)__t);
307    // FIXME: Make this abort
308#endif
309}
310
311template <class _From, class _To>
312struct __can_dynamic_cast : public _LIBCPP_BOOL_CONSTANT(
313              is_polymorphic<_From>::value &&
314                 (!is_base_of<_To, _From>::value ||
315                   is_convertible<const _From*, const _To*>::value)) {};
316
317template <class _Ep>
318inline _LIBCPP_INLINE_VISIBILITY
319void
320rethrow_if_nested(const _Ep& __e,
321                  typename enable_if< __can_dynamic_cast<_Ep, nested_exception>::value>::type* = 0)
322{
323    const nested_exception* __nep = dynamic_cast<const nested_exception*>(_VSTD::addressof(__e));
324    if (__nep)
325        __nep->rethrow_nested();
326}
327
328template <class _Ep>
329inline _LIBCPP_INLINE_VISIBILITY
330void
331rethrow_if_nested(const _Ep&,
332                  typename enable_if<!__can_dynamic_cast<_Ep, nested_exception>::value>::type* = 0)
333{
334}
335
336}  // std
337
338#endif  // _LIBCPP_EXCEPTION
339