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
85#if defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_NO_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_MICROSOFT) || defined(_LIBCPP_NO_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_MICROSOFT || _LIBCPP_NO_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>
166exception_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>
225exception_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_ALWAYS_INLINE void
263#ifndef _LIBCPP_CXX03_LANG
264    __do_throw(_Tp&& __t)
265#else
266    __do_throw (_Tp& __t)
267#endif  // _LIBCPP_CXX03_LANG
268    {
269        throw __nested<_Up>(_VSTD::forward<_Tp>(__t));
270    }
271};
272
273template <class _Tp, class _Up>
274struct __throw_with_nested<_Tp, _Up, false> {
275    _LIBCPP_NORETURN static inline _LIBCPP_ALWAYS_INLINE void
276#ifndef _LIBCPP_CXX03_LANG
277    __do_throw(_Tp&& __t)
278#else
279    __do_throw (_Tp& __t)
280#endif  // _LIBCPP_CXX03_LANG
281    {
282        throw _VSTD::forward<_Tp>(__t);
283    }
284};
285#endif
286
287template <class _Tp>
288_LIBCPP_NORETURN
289void
290#ifndef _LIBCPP_CXX03_LANG
291throw_with_nested(_Tp&& __t)
292#else
293throw_with_nested (_Tp& __t)
294#endif // _LIBCPP_CXX03_LANG
295{
296#ifndef _LIBCPP_NO_EXCEPTIONS
297    typedef typename decay<_Tp>::type _Up;
298    static_assert( is_copy_constructible<_Up>::value, "type thrown must be CopyConstructible");
299    __throw_with_nested<_Tp, _Up,
300        is_class<_Up>::value &&
301        !is_base_of<nested_exception, _Up>::value &&
302        !__libcpp_is_final<_Up>::value>::
303            __do_throw(_VSTD::forward<_Tp>(__t));
304#else
305    ((void)__t);
306    // FIXME: Make this abort
307#endif
308}
309
310template <class _From, class _To>
311struct __can_dynamic_cast : public _LIBCPP_BOOL_CONSTANT(
312              is_polymorphic<_From>::value &&
313                 (!is_base_of<_To, _From>::value ||
314                   is_convertible<const _From*, const _To*>::value)) {};
315
316template <class _Ep>
317inline _LIBCPP_INLINE_VISIBILITY
318void
319rethrow_if_nested(const _Ep& __e,
320                  typename enable_if< __can_dynamic_cast<_Ep, nested_exception>::value>::type* = 0)
321{
322    const nested_exception* __nep = dynamic_cast<const nested_exception*>(_VSTD::addressof(__e));
323    if (__nep)
324        __nep->rethrow_nested();
325}
326
327template <class _Ep>
328inline _LIBCPP_INLINE_VISIBILITY
329void
330rethrow_if_nested(const _Ep&,
331                  typename enable_if<!__can_dynamic_cast<_Ep, nested_exception>::value>::type* = 0)
332{
333}
334
335}  // std
336
337#endif  // _LIBCPP_EXCEPTION
338