1// <system_error> -*- C++ -*-
2
3// Copyright (C) 2007-2016 Free Software Foundation, Inc.
4//
5// This file is part of the GNU ISO C++ Library.  This library is free
6// software; you can redistribute it and/or modify it under the
7// terms of the GNU General Public License as published by the
8// Free Software Foundation; either version 3, or (at your option)
9// any later version.
10
11// This library is distributed in the hope that it will be useful,
12// but WITHOUT ANY WARRANTY; without even the implied warranty of
13// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14// GNU General Public License for more details.
15
16// Under Section 7 of GPL version 3, you are granted additional
17// permissions described in the GCC Runtime Library Exception, version
18// 3.1, as published by the Free Software Foundation.
19
20// You should have received a copy of the GNU General Public License and
21// a copy of the GCC Runtime Library Exception along with this program;
22// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
23// <http://www.gnu.org/licenses/>.
24
25/** @file include/system_error
26 *  This is a Standard C++ Library header.
27 */
28
29#ifndef _GLIBCXX_SYSTEM_ERROR
30#define _GLIBCXX_SYSTEM_ERROR 1
31
32#pragma GCC system_header
33
34#if __cplusplus < 201103L
35# include <bits/c++0x_warning.h>
36#else
37
38#include <bits/c++config.h>
39#include <bits/error_constants.h>
40#include <iosfwd>
41#include <stdexcept>
42
43namespace std _GLIBCXX_VISIBILITY(default)
44{
45_GLIBCXX_BEGIN_NAMESPACE_VERSION
46
47  class error_code;
48  class error_condition;
49  class system_error;
50
51  /// is_error_code_enum
52  template<typename _Tp>
53    struct is_error_code_enum : public false_type { };
54
55  /// is_error_condition_enum
56  template<typename _Tp>
57    struct is_error_condition_enum : public false_type { };
58
59  template<>
60    struct is_error_condition_enum<errc>
61    : public true_type { };
62
63  inline namespace _V2 {
64
65  /// error_category
66  class error_category
67  {
68  public:
69    constexpr error_category() noexcept = default;
70
71    virtual ~error_category();
72
73    error_category(const error_category&) = delete;
74    error_category& operator=(const error_category&) = delete;
75
76    virtual const char*
77    name() const noexcept = 0;
78
79    // We need two different virtual functions here, one returning a
80    // COW string and one returning an SSO string. Their positions in the
81    // vtable must be consistent for dynamic dispatch to work, but which one
82    // the name "message()" finds depends on which ABI the caller is using.
83#if _GLIBCXX_USE_CXX11_ABI
84  private:
85    _GLIBCXX_DEFAULT_ABI_TAG
86    virtual __cow_string
87    _M_message(int) const;
88
89  public:
90    _GLIBCXX_DEFAULT_ABI_TAG
91    virtual string
92    message(int) const = 0;
93#else
94    virtual string
95    message(int) const = 0;
96
97  private:
98    virtual __sso_string
99    _M_message(int) const;
100#endif
101
102  public:
103    virtual error_condition
104    default_error_condition(int __i) const noexcept;
105
106    virtual bool
107    equivalent(int __i, const error_condition& __cond) const noexcept;
108
109    virtual bool
110    equivalent(const error_code& __code, int __i) const noexcept;
111
112    bool
113    operator<(const error_category& __other) const noexcept
114    { return less<const error_category*>()(this, &__other); }
115
116    bool
117    operator==(const error_category& __other) const noexcept
118    { return this == &__other; }
119
120    bool
121    operator!=(const error_category& __other) const noexcept
122    { return this != &__other; }
123  };
124
125  // DR 890.
126  _GLIBCXX_CONST const error_category& system_category() noexcept;
127  _GLIBCXX_CONST const error_category& generic_category() noexcept;
128
129  } // end inline namespace
130
131  error_code make_error_code(errc) noexcept;
132
133  template<typename _Tp>
134    struct hash;
135
136  /// error_code
137  // Implementation-specific error identification
138  struct error_code
139  {
140    error_code() noexcept
141    : _M_value(0), _M_cat(&system_category()) { }
142
143    error_code(int __v, const error_category& __cat) noexcept
144    : _M_value(__v), _M_cat(&__cat) { }
145
146    template<typename _ErrorCodeEnum, typename = typename
147	     enable_if<is_error_code_enum<_ErrorCodeEnum>::value>::type>
148      error_code(_ErrorCodeEnum __e) noexcept
149      { *this = make_error_code(__e); }
150
151    void
152    assign(int __v, const error_category& __cat) noexcept
153    {
154      _M_value = __v;
155      _M_cat = &__cat;
156    }
157
158    void
159    clear() noexcept
160    { assign(0, system_category()); }
161
162    // DR 804.
163    template<typename _ErrorCodeEnum>
164      typename enable_if<is_error_code_enum<_ErrorCodeEnum>::value,
165			 error_code&>::type
166      operator=(_ErrorCodeEnum __e) noexcept
167      { return *this = make_error_code(__e); }
168
169    int
170    value() const noexcept { return _M_value; }
171
172    const error_category&
173    category() const noexcept { return *_M_cat; }
174
175    error_condition
176    default_error_condition() const noexcept;
177
178    _GLIBCXX_DEFAULT_ABI_TAG
179    string
180    message() const
181    { return category().message(value()); }
182
183    explicit operator bool() const noexcept
184    { return _M_value != 0; }
185
186    // DR 804.
187  private:
188    friend class hash<error_code>;
189
190    int            		_M_value;
191    const error_category* 	_M_cat;
192  };
193
194  // 19.4.2.6 non-member functions
195  inline error_code
196  make_error_code(errc __e) noexcept
197  { return error_code(static_cast<int>(__e), generic_category()); }
198
199  inline bool
200  operator<(const error_code& __lhs, const error_code& __rhs) noexcept
201  {
202    return (__lhs.category() < __rhs.category()
203	    || (__lhs.category() == __rhs.category()
204		&& __lhs.value() < __rhs.value()));
205  }
206
207  template<typename _CharT, typename _Traits>
208    basic_ostream<_CharT, _Traits>&
209    operator<<(basic_ostream<_CharT, _Traits>& __os, const error_code& __e)
210    { return (__os << __e.category().name() << ':' << __e.value()); }
211
212  error_condition make_error_condition(errc) noexcept;
213
214  /// error_condition
215  // Portable error identification
216  struct error_condition
217  {
218    error_condition() noexcept
219    : _M_value(0), _M_cat(&generic_category()) { }
220
221    error_condition(int __v, const error_category& __cat) noexcept
222    : _M_value(__v), _M_cat(&__cat) { }
223
224    template<typename _ErrorConditionEnum, typename = typename
225	 enable_if<is_error_condition_enum<_ErrorConditionEnum>::value>::type>
226      error_condition(_ErrorConditionEnum __e) noexcept
227      { *this = make_error_condition(__e); }
228
229    void
230    assign(int __v, const error_category& __cat) noexcept
231    {
232      _M_value = __v;
233      _M_cat = &__cat;
234    }
235
236    // DR 804.
237    template<typename _ErrorConditionEnum>
238      typename enable_if<is_error_condition_enum
239			 <_ErrorConditionEnum>::value, error_condition&>::type
240      operator=(_ErrorConditionEnum __e) noexcept
241      { return *this = make_error_condition(__e); }
242
243    void
244    clear() noexcept
245    { assign(0, generic_category()); }
246
247    // 19.4.3.4 observers
248    int
249    value() const noexcept { return _M_value; }
250
251    const error_category&
252    category() const noexcept { return *_M_cat; }
253
254    _GLIBCXX_DEFAULT_ABI_TAG
255    string
256    message() const
257    { return category().message(value()); }
258
259    explicit operator bool() const noexcept
260    { return _M_value != 0; }
261
262    // DR 804.
263  private:
264    int 			_M_value;
265    const error_category* 	_M_cat;
266  };
267
268  // 19.4.3.6 non-member functions
269  inline error_condition
270  make_error_condition(errc __e) noexcept
271  { return error_condition(static_cast<int>(__e), generic_category()); }
272
273  inline bool
274  operator<(const error_condition& __lhs,
275	    const error_condition& __rhs) noexcept
276  {
277    return (__lhs.category() < __rhs.category()
278	    || (__lhs.category() == __rhs.category()
279		&& __lhs.value() < __rhs.value()));
280  }
281
282  // 19.4.4 Comparison operators
283  inline bool
284  operator==(const error_code& __lhs, const error_code& __rhs) noexcept
285  { return (__lhs.category() == __rhs.category()
286	    && __lhs.value() == __rhs.value()); }
287
288  inline bool
289  operator==(const error_code& __lhs, const error_condition& __rhs) noexcept
290  {
291    return (__lhs.category().equivalent(__lhs.value(), __rhs)
292	    || __rhs.category().equivalent(__lhs, __rhs.value()));
293  }
294
295  inline bool
296  operator==(const error_condition& __lhs, const error_code& __rhs) noexcept
297  {
298    return (__rhs.category().equivalent(__rhs.value(), __lhs)
299	    || __lhs.category().equivalent(__rhs, __lhs.value()));
300  }
301
302  inline bool
303  operator==(const error_condition& __lhs,
304	     const error_condition& __rhs) noexcept
305  {
306    return (__lhs.category() == __rhs.category()
307	    && __lhs.value() == __rhs.value());
308  }
309
310  inline bool
311  operator!=(const error_code& __lhs, const error_code& __rhs) noexcept
312  { return !(__lhs == __rhs); }
313
314  inline bool
315  operator!=(const error_code& __lhs, const error_condition& __rhs) noexcept
316  { return !(__lhs == __rhs); }
317
318  inline bool
319  operator!=(const error_condition& __lhs, const error_code& __rhs) noexcept
320  { return !(__lhs == __rhs); }
321
322  inline bool
323  operator!=(const error_condition& __lhs,
324	     const error_condition& __rhs) noexcept
325  { return !(__lhs == __rhs); }
326
327
328  /**
329   *  @brief Thrown to indicate error code of underlying system.
330   *
331   *  @ingroup exceptions
332   */
333  class system_error : public std::runtime_error
334  {
335  private:
336    error_code 	_M_code;
337
338  public:
339    system_error(error_code __ec = error_code())
340    : runtime_error(__ec.message()), _M_code(__ec) { }
341
342    system_error(error_code __ec, const string& __what)
343    : runtime_error(__what + ": " + __ec.message()), _M_code(__ec) { }
344
345    system_error(error_code __ec, const char* __what)
346    : runtime_error(__what + (": " + __ec.message())), _M_code(__ec) { }
347
348    system_error(int __v, const error_category& __ecat, const char* __what)
349    : system_error(error_code(__v, __ecat), __what) { }
350
351    system_error(int __v, const error_category& __ecat)
352    : runtime_error(error_code(__v, __ecat).message()),
353      _M_code(__v, __ecat) { }
354
355    system_error(int __v, const error_category& __ecat, const string& __what)
356    : runtime_error(__what + ": " + error_code(__v, __ecat).message()),
357      _M_code(__v, __ecat) { }
358
359    virtual ~system_error() noexcept;
360
361    const error_code&
362    code() const noexcept { return _M_code; }
363  };
364
365_GLIBCXX_END_NAMESPACE_VERSION
366} // namespace
367
368#ifndef _GLIBCXX_COMPATIBILITY_CXX0X
369
370#include <bits/functional_hash.h>
371
372namespace std _GLIBCXX_VISIBILITY(default)
373{
374_GLIBCXX_BEGIN_NAMESPACE_VERSION
375
376  // DR 1182.
377  /// std::hash specialization for error_code.
378  template<>
379    struct hash<error_code>
380    : public __hash_base<size_t, error_code>
381    {
382      size_t
383      operator()(const error_code& __e) const noexcept
384      {
385	const size_t __tmp = std::_Hash_impl::hash(__e._M_value);
386	return std::_Hash_impl::__hash_combine(__e._M_cat, __tmp);
387      }
388    };
389
390_GLIBCXX_END_NAMESPACE_VERSION
391} // namespace
392
393#endif // _GLIBCXX_COMPATIBILITY_CXX0X
394
395#endif // C++11
396
397#endif // _GLIBCXX_SYSTEM_ERROR
398