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 <type_traits>
83#if defined(_LIBCPP_NO_EXCEPTIONS)
84#include <cstdio>
85#include <cstdlib>
86#endif
87
88#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
89#pragma GCC system_header
90#endif
91
92namespace std  // purposefully not using versioning namespace
93{
94
95class _LIBCPP_EXCEPTION_ABI exception
96{
97public:
98    _LIBCPP_INLINE_VISIBILITY exception() _NOEXCEPT {}
99    virtual ~exception() _NOEXCEPT;
100    virtual const char* what() const _NOEXCEPT;
101};
102
103class _LIBCPP_EXCEPTION_ABI bad_exception
104    : public exception
105{
106public:
107    _LIBCPP_INLINE_VISIBILITY bad_exception() _NOEXCEPT {}
108    virtual ~bad_exception() _NOEXCEPT;
109    virtual const char* what() const _NOEXCEPT;
110};
111
112typedef void (*unexpected_handler)();
113_LIBCPP_FUNC_VIS unexpected_handler set_unexpected(unexpected_handler) _NOEXCEPT;
114_LIBCPP_FUNC_VIS unexpected_handler get_unexpected() _NOEXCEPT;
115_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void unexpected();
116
117typedef void (*terminate_handler)();
118_LIBCPP_FUNC_VIS terminate_handler set_terminate(terminate_handler) _NOEXCEPT;
119_LIBCPP_FUNC_VIS terminate_handler get_terminate() _NOEXCEPT;
120_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void terminate() _NOEXCEPT;
121
122_LIBCPP_FUNC_VIS bool uncaught_exception() _NOEXCEPT;
123_LIBCPP_FUNC_VIS int uncaught_exceptions() _NOEXCEPT;
124
125class _LIBCPP_TYPE_VIS exception_ptr;
126
127_LIBCPP_FUNC_VIS exception_ptr current_exception() _NOEXCEPT;
128_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void rethrow_exception(exception_ptr);
129
130class _LIBCPP_TYPE_VIS exception_ptr
131{
132    void* __ptr_;
133public:
134    _LIBCPP_INLINE_VISIBILITY exception_ptr() _NOEXCEPT : __ptr_() {}
135    _LIBCPP_INLINE_VISIBILITY exception_ptr(nullptr_t) _NOEXCEPT : __ptr_() {}
136    exception_ptr(const exception_ptr&) _NOEXCEPT;
137    exception_ptr& operator=(const exception_ptr&) _NOEXCEPT;
138    ~exception_ptr() _NOEXCEPT;
139
140    _LIBCPP_INLINE_VISIBILITY
141    _LIBCPP_EXPLICIT
142        operator bool() const _NOEXCEPT {return __ptr_ != nullptr;}
143
144    friend _LIBCPP_INLINE_VISIBILITY
145    bool operator==(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT
146        {return __x.__ptr_ == __y.__ptr_;}
147    friend _LIBCPP_INLINE_VISIBILITY
148    bool operator!=(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT
149        {return !(__x == __y);}
150
151    friend _LIBCPP_FUNC_VIS exception_ptr current_exception() _NOEXCEPT;
152    friend _LIBCPP_FUNC_VIS void rethrow_exception(exception_ptr);
153};
154
155template<class _Ep>
156exception_ptr
157make_exception_ptr(_Ep __e) _NOEXCEPT
158{
159#ifndef _LIBCPP_NO_EXCEPTIONS
160    try
161    {
162        throw __e;
163    }
164    catch (...)
165    {
166        return current_exception();
167    }
168#endif  // _LIBCPP_NO_EXCEPTIONS
169}
170
171// nested_exception
172
173class _LIBCPP_EXCEPTION_ABI nested_exception
174{
175    exception_ptr __ptr_;
176public:
177    nested_exception() _NOEXCEPT;
178//     nested_exception(const nested_exception&) noexcept = default;
179//     nested_exception& operator=(const nested_exception&) noexcept = default;
180    virtual ~nested_exception() _NOEXCEPT;
181
182    // access functions
183    _LIBCPP_NORETURN void rethrow_nested() const;
184    _LIBCPP_INLINE_VISIBILITY exception_ptr nested_ptr() const _NOEXCEPT {return __ptr_;}
185};
186
187template <class _Tp>
188struct __nested
189    : public _Tp,
190      public nested_exception
191{
192    _LIBCPP_INLINE_VISIBILITY explicit __nested(const _Tp& __t) : _Tp(__t) {}
193};
194
195template <class _Tp>
196_LIBCPP_NORETURN
197void
198#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
199throw_with_nested(_Tp&& __t, typename enable_if<
200                  is_class<typename remove_reference<_Tp>::type>::value &&
201                  !is_base_of<nested_exception, typename remove_reference<_Tp>::type>::value
202                  && !__libcpp_is_final<typename remove_reference<_Tp>::type>::value
203                                    >::type* = 0)
204#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
205throw_with_nested (_Tp& __t, typename enable_if<
206                  is_class<_Tp>::value && !is_base_of<nested_exception, _Tp>::value
207                                    >::type* = 0)
208#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
209{
210#ifndef _LIBCPP_NO_EXCEPTIONS
211    throw __nested<typename remove_reference<_Tp>::type>(_VSTD::forward<_Tp>(__t));
212#endif
213}
214
215template <class _Tp>
216_LIBCPP_NORETURN
217void
218#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
219throw_with_nested(_Tp&& __t, typename enable_if<
220                  !is_class<typename remove_reference<_Tp>::type>::value ||
221                  is_base_of<nested_exception, typename remove_reference<_Tp>::type>::value
222                  || __libcpp_is_final<typename remove_reference<_Tp>::type>::value
223                                    >::type* = 0)
224#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
225throw_with_nested (_Tp& __t, typename enable_if<
226                  !is_class<_Tp>::value || is_base_of<nested_exception, _Tp>::value
227                                    >::type* = 0)
228#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
229{
230#ifndef _LIBCPP_NO_EXCEPTIONS
231    throw _VSTD::forward<_Tp>(__t);
232#endif
233}
234
235template <class _Ep>
236inline _LIBCPP_INLINE_VISIBILITY
237void
238rethrow_if_nested(const _Ep& __e, typename enable_if<
239                                   is_polymorphic<_Ep>::value
240                                                   >::type* = 0)
241{
242    const nested_exception* __nep = dynamic_cast<const nested_exception*>(_VSTD::addressof(__e));
243    if (__nep)
244        __nep->rethrow_nested();
245}
246
247template <class _Ep>
248inline _LIBCPP_INLINE_VISIBILITY
249void
250rethrow_if_nested(const _Ep&, typename enable_if<
251                                   !is_polymorphic<_Ep>::value
252                                                   >::type* = 0)
253{
254}
255
256}  // std
257
258_LIBCPP_BEGIN_NAMESPACE_STD
259
260template <class _Exception>
261_LIBCPP_INLINE_VISIBILITY
262inline void __libcpp_throw(_Exception const& __e) {
263#ifndef _LIBCPP_NO_EXCEPTIONS
264    throw __e;
265#else
266    _VSTD::fprintf(stderr, "%s\n", __e.what());
267    _VSTD::abort();
268#endif
269}
270
271_LIBCPP_END_NAMESPACE_STD
272
273#endif  // _LIBCPP_EXCEPTION
274