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() throw();
24    exception(const exception&) throw();
25    exception& operator=(const exception&) throw();
26    virtual ~exception() throw();
27    virtual const char* what() const throw();
28};
29
30class bad_exception
31    : public exception
32{
33public:
34    bad_exception() throw();
35    bad_exception(const bad_exception&) throw();
36    bad_exception& operator=(const bad_exception&) throw();
37    virtual ~bad_exception() throw();
38    virtual const char* what() const throw();
39};
40
41typedef void (*unexpected_handler)();
42unexpected_handler set_unexpected(unexpected_handler  f ) throw();
43unexpected_handler get_unexpected() throw();
44void unexpected [[noreturn]] ();
45
46typedef void (*terminate_handler)();
47terminate_handler set_terminate(terminate_handler  f ) throw();
48terminate_handler get_terminate() throw();
49void terminate [[noreturn]] ();
50
51bool uncaught_exception() throw();
52
53typedef unspecified exception_ptr;
54
55exception_ptr current_exception();
56void rethrow_exception [[noreturn]] (exception_ptr p);
57template<class E> exception_ptr make_exception_ptr(E e);
58
59class nested_exception
60{
61public:
62    nested_exception() throw();
63    nested_exception(const nested_exception&) throw() = default;
64    nested_exception& operator=(const nested_exception&) throw() = default;
65    virtual ~nested_exception() = default;
66
67    // access functions
68    void rethrow_nested [[noreturn]] () const;
69    exception_ptr nested_ptr() const;
70};
71
72template <class T> void throw_with_nested [[noreturn]] (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() throw() {}
92    virtual ~exception() throw();
93    virtual const char* what() const throw();
94};
95
96class _LIBCPP_EXCEPTION_ABI bad_exception
97    : public exception
98{
99public:
100    _LIBCPP_INLINE_VISIBILITY bad_exception() throw() {}
101    virtual ~bad_exception() throw();
102    virtual const char* what() const throw();
103};
104
105typedef void (*unexpected_handler)();
106_LIBCPP_VISIBLE unexpected_handler set_unexpected(unexpected_handler) throw();
107_LIBCPP_VISIBLE unexpected_handler get_unexpected() throw();
108_LIBCPP_VISIBLE void unexpected();
109
110typedef void (*terminate_handler)();
111_LIBCPP_VISIBLE terminate_handler set_terminate(terminate_handler) throw();
112_LIBCPP_VISIBLE terminate_handler get_terminate() throw();
113_LIBCPP_VISIBLE void terminate() __attribute__((__noreturn__));
114
115_LIBCPP_VISIBLE bool uncaught_exception() throw();
116
117class exception_ptr;
118
119exception_ptr current_exception();
120void rethrow_exception(exception_ptr);  // noreturn
121
122class _LIBCPP_VISIBLE exception_ptr
123{
124    void* __ptr_;
125public:
126    _LIBCPP_INLINE_VISIBILITY exception_ptr()  : __ptr_() {}
127    _LIBCPP_INLINE_VISIBILITY exception_ptr(nullptr_t) : __ptr_() {}
128    exception_ptr(const exception_ptr&);
129    exception_ptr& operator=(const exception_ptr&);
130    ~exception_ptr();
131
132    _LIBCPP_INLINE_VISIBILITY
133    // explicit
134        operator bool() const {return __ptr_ != nullptr;}
135
136    friend _LIBCPP_INLINE_VISIBILITY
137    bool operator==(const exception_ptr& __x, const exception_ptr& __y)
138        {return __x.__ptr_ == __y.__ptr_;}
139    friend _LIBCPP_INLINE_VISIBILITY
140    bool operator!=(const exception_ptr& __x, const exception_ptr& __y)
141        {return !(__x == __y);}
142
143    friend exception_ptr current_exception();
144    friend void rethrow_exception(exception_ptr);  // noreturn
145};
146
147template<class _E>
148exception_ptr
149make_exception_ptr(_E __e)
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();
170//     nested_exception(const nested_exception&) throw() = default;
171//     nested_exception& operator=(const nested_exception&) throw() = default;
172    virtual ~nested_exception();
173
174    // access functions
175    void rethrow_nested /*[[noreturn]]*/ () const;
176    _LIBCPP_INLINE_VISIBILITY exception_ptr nested_ptr() const {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>
188void
189#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
190throw_with_nested /*[[noreturn]]*/ (_Tp&& __t, typename enable_if<
191                  is_class<typename remove_reference<_Tp>::type>::value &&
192                  !is_base_of<nested_exception, typename remove_reference<_Tp>::type>::value
193                                    >::type* = 0)
194#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
195throw_with_nested (_Tp& __t, typename enable_if<
196                  is_class<_Tp>::value && !is_base_of<nested_exception, _Tp>::value
197                                    >::type* = 0)
198#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
199{
200#ifndef _LIBCPP_NO_EXCEPTIONS
201    throw __nested<typename remove_reference<_Tp>::type>(_STD::forward<_Tp>(__t));
202#endif
203}
204
205template <class _Tp>
206void
207#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
208throw_with_nested /*[[noreturn]]*/ (_Tp&& __t, typename enable_if<
209                  !is_class<typename remove_reference<_Tp>::type>::value ||
210                  is_base_of<nested_exception, typename remove_reference<_Tp>::type>::value
211                                    >::type* = 0)
212#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
213throw_with_nested (_Tp& __t, typename enable_if<
214                  !is_class<_Tp>::value || is_base_of<nested_exception, _Tp>::value
215                                    >::type* = 0)
216#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
217{
218#ifndef _LIBCPP_NO_EXCEPTIONS
219    throw _STD::forward<_Tp>(__t);
220#endif
221}
222
223template <class _E>
224inline _LIBCPP_INLINE_VISIBILITY
225void
226rethrow_if_nested(const _E& __e, typename enable_if<
227                                   is_polymorphic<_E>::value
228                                                   >::type* = 0)
229{
230    const nested_exception* __nep = dynamic_cast<const nested_exception*>(&__e);
231    if (__nep)
232        __nep->rethrow_nested();
233}
234
235template <class _E>
236inline _LIBCPP_INLINE_VISIBILITY
237void
238rethrow_if_nested(const _E& __e, typename enable_if<
239                                   !is_polymorphic<_E>::value
240                                                   >::type* = 0)
241{
242}
243
244}  // std
245
246#endif  // _LIBCPP_EXCEPTION
247