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;
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 <type_traits>
82
83#pragma GCC system_header
84
85namespace std  // purposefully not using versioning namespace
86{
87
88class _LIBCPP_EXCEPTION_ABI exception
89{
90public:
91    _LIBCPP_INLINE_VISIBILITY exception() _NOEXCEPT {}
92    virtual ~exception() _NOEXCEPT;
93    virtual const char* what() const _NOEXCEPT;
94};
95
96class _LIBCPP_EXCEPTION_ABI bad_exception
97    : public exception
98{
99public:
100    _LIBCPP_INLINE_VISIBILITY bad_exception() _NOEXCEPT {}
101    virtual ~bad_exception() _NOEXCEPT;
102    virtual const char* what() const _NOEXCEPT;
103};
104
105typedef void (*unexpected_handler)();
106_LIBCPP_VISIBLE unexpected_handler set_unexpected(unexpected_handler) _NOEXCEPT;
107_LIBCPP_VISIBLE unexpected_handler get_unexpected() _NOEXCEPT;
108_ATTRIBUTE(noreturn) _LIBCPP_VISIBLE void unexpected();
109
110typedef void (*terminate_handler)();
111_LIBCPP_VISIBLE terminate_handler set_terminate(terminate_handler) _NOEXCEPT;
112_LIBCPP_VISIBLE terminate_handler get_terminate() _NOEXCEPT;
113_ATTRIBUTE(noreturn) _LIBCPP_VISIBLE void terminate() _NOEXCEPT;
114
115_LIBCPP_VISIBLE bool uncaught_exception() _NOEXCEPT;
116
117class exception_ptr;
118
119exception_ptr current_exception() _NOEXCEPT;
120_ATTRIBUTE(noreturn) void rethrow_exception(exception_ptr);
121
122class _LIBCPP_VISIBLE exception_ptr
123{
124    void* __ptr_;
125public:
126    _LIBCPP_INLINE_VISIBILITY exception_ptr() _NOEXCEPT : __ptr_() {}
127    _LIBCPP_INLINE_VISIBILITY exception_ptr(nullptr_t) _NOEXCEPT : __ptr_() {}
128    exception_ptr(const exception_ptr&) _NOEXCEPT;
129    exception_ptr& operator=(const exception_ptr&) _NOEXCEPT;
130    ~exception_ptr() _NOEXCEPT;
131
132    _LIBCPP_INLINE_VISIBILITY
133    // explicit
134        operator bool() const _NOEXCEPT {return __ptr_ != nullptr;}
135
136    friend _LIBCPP_INLINE_VISIBILITY
137    bool operator==(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT
138        {return __x.__ptr_ == __y.__ptr_;}
139    friend _LIBCPP_INLINE_VISIBILITY
140    bool operator!=(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT
141        {return !(__x == __y);}
142
143    friend exception_ptr current_exception() _NOEXCEPT;
144    _ATTRIBUTE(noreturn) friend void rethrow_exception(exception_ptr);
145};
146
147template<class _E>
148exception_ptr
149make_exception_ptr(_E __e) _NOEXCEPT
150{
151#ifndef _LIBCPP_NO_EXCEPTIONS
152    try
153    {
154        throw __e;
155    }
156    catch (...)
157    {
158        return current_exception();
159    }
160#endif  // _LIBCPP_NO_EXCEPTIONS
161}
162
163// nested_exception
164
165class _LIBCPP_EXCEPTION_ABI nested_exception
166{
167    exception_ptr __ptr_;
168public:
169    nested_exception() _NOEXCEPT;
170//     nested_exception(const nested_exception&) noexcept = default;
171//     nested_exception& operator=(const nested_exception&) noexcept = default;
172    virtual ~nested_exception() _NOEXCEPT;
173
174    // access functions
175    _ATTRIBUTE(noreturn) void rethrow_nested() const;
176    _LIBCPP_INLINE_VISIBILITY exception_ptr nested_ptr() const _NOEXCEPT {return __ptr_;}
177};
178
179template <class _Tp>
180struct __nested
181    : public _Tp,
182      public nested_exception
183{
184    _LIBCPP_INLINE_VISIBILITY explicit __nested(const _Tp& __t) : _Tp(__t) {}
185};
186
187template <class _Tp>
188_ATTRIBUTE(noreturn)
189void
190#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
191throw_with_nested(_Tp&& __t, typename enable_if<
192                  is_class<typename remove_reference<_Tp>::type>::value &&
193                  !is_base_of<nested_exception, typename remove_reference<_Tp>::type>::value
194                                    >::type* = 0)
195#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
196throw_with_nested (_Tp& __t, typename enable_if<
197                  is_class<_Tp>::value && !is_base_of<nested_exception, _Tp>::value
198                                    >::type* = 0)
199#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
200{
201#ifndef _LIBCPP_NO_EXCEPTIONS
202    throw __nested<typename remove_reference<_Tp>::type>(_VSTD::forward<_Tp>(__t));
203#endif
204}
205
206template <class _Tp>
207_ATTRIBUTE(noreturn)
208void
209#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
210throw_with_nested(_Tp&& __t, typename enable_if<
211                  !is_class<typename remove_reference<_Tp>::type>::value ||
212                  is_base_of<nested_exception, typename remove_reference<_Tp>::type>::value
213                                    >::type* = 0)
214#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
215throw_with_nested (_Tp& __t, typename enable_if<
216                  !is_class<_Tp>::value || is_base_of<nested_exception, _Tp>::value
217                                    >::type* = 0)
218#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
219{
220#ifndef _LIBCPP_NO_EXCEPTIONS
221    throw _VSTD::forward<_Tp>(__t);
222#endif
223}
224
225template <class _E>
226inline _LIBCPP_INLINE_VISIBILITY
227void
228rethrow_if_nested(const _E& __e, typename enable_if<
229                                   is_polymorphic<_E>::value
230                                                   >::type* = 0)
231{
232    const nested_exception* __nep = dynamic_cast<const nested_exception*>(&__e);
233    if (__nep)
234        __nep->rethrow_nested();
235}
236
237template <class _E>
238inline _LIBCPP_INLINE_VISIBILITY
239void
240rethrow_if_nested(const _E& __e, typename enable_if<
241                                   !is_polymorphic<_E>::value
242                                                   >::type* = 0)
243{
244}
245
246}  // std
247
248#endif  // _LIBCPP_EXCEPTION
249