1// <system_error> -*- C++ -*-
2
3// Copyright (C) 2007-2014 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 error_category;
50  class system_error;
51
52  /// is_error_code_enum
53  template<typename _Tp>
54    struct is_error_code_enum : public false_type { };
55
56  /// is_error_condition_enum
57  template<typename _Tp>
58    struct is_error_condition_enum : public false_type { };
59
60  template<>
61    struct is_error_condition_enum<errc>
62    : public true_type { };
63
64
65  /// error_category
66  class error_category
67  {
68  public:
69#ifdef _GLIBCXX_COMPATIBILITY_CXX0X
70    error_category() noexcept;
71#else
72    constexpr error_category() noexcept = default;
73#endif
74
75    virtual ~error_category();
76
77    error_category(const error_category&) = delete;
78    error_category& operator=(const error_category&) = delete;
79
80    virtual const char*
81    name() const noexcept = 0;
82
83    virtual string
84    message(int) const = 0;
85
86    virtual error_condition
87    default_error_condition(int __i) const noexcept;
88
89    virtual bool
90    equivalent(int __i, const error_condition& __cond) const noexcept;
91
92    virtual bool
93    equivalent(const error_code& __code, int __i) const noexcept;
94
95    bool
96    operator<(const error_category& __other) const noexcept
97    { return less<const error_category*>()(this, &__other); }
98
99    bool
100    operator==(const error_category& __other) const noexcept
101    { return this == &__other; }
102
103    bool
104    operator!=(const error_category& __other) const noexcept
105    { return this != &__other; }
106  };
107
108  // DR 890.
109  _GLIBCXX_CONST const error_category& system_category() noexcept;
110  _GLIBCXX_CONST const error_category& generic_category() noexcept;
111
112  error_code make_error_code(errc) noexcept;
113
114  template<typename _Tp>
115    struct hash;
116
117  /// error_code
118  // Implementation-specific error identification
119  struct error_code
120  {
121    error_code() noexcept
122    : _M_value(0), _M_cat(&system_category()) { }
123
124    error_code(int __v, const error_category& __cat) noexcept
125    : _M_value(__v), _M_cat(&__cat) { }
126
127    template<typename _ErrorCodeEnum, typename = typename
128	     enable_if<is_error_code_enum<_ErrorCodeEnum>::value>::type>
129      error_code(_ErrorCodeEnum __e) noexcept
130      { *this = make_error_code(__e); }
131
132    void
133    assign(int __v, const error_category& __cat) noexcept
134    {
135      _M_value = __v;
136      _M_cat = &__cat;
137    }
138
139    void
140    clear() noexcept
141    { assign(0, system_category()); }
142
143    // DR 804.
144    template<typename _ErrorCodeEnum>
145      typename enable_if<is_error_code_enum<_ErrorCodeEnum>::value,
146			 error_code&>::type
147      operator=(_ErrorCodeEnum __e) noexcept
148      { return *this = make_error_code(__e); }
149
150    int
151    value() const noexcept { return _M_value; }
152
153    const error_category&
154    category() const noexcept { return *_M_cat; }
155
156    error_condition
157    default_error_condition() const noexcept;
158
159    string
160    message() const
161    { return category().message(value()); }
162
163    explicit operator bool() const noexcept
164    { return _M_value != 0 ? true : false; }
165
166    // DR 804.
167  private:
168    friend class hash<error_code>;
169
170    int            		_M_value;
171    const error_category* 	_M_cat;
172  };
173
174  // 19.4.2.6 non-member functions
175  inline error_code
176  make_error_code(errc __e) noexcept
177  { return error_code(static_cast<int>(__e), generic_category()); }
178
179  inline bool
180  operator<(const error_code& __lhs, const error_code& __rhs) noexcept
181  {
182    return (__lhs.category() < __rhs.category()
183	    || (__lhs.category() == __rhs.category()
184		&& __lhs.value() < __rhs.value()));
185  }
186
187  template<typename _CharT, typename _Traits>
188    basic_ostream<_CharT, _Traits>&
189    operator<<(basic_ostream<_CharT, _Traits>& __os, const error_code& __e)
190    { return (__os << __e.category().name() << ':' << __e.value()); }
191
192  error_condition make_error_condition(errc) noexcept;
193
194  /// error_condition
195  // Portable error identification
196  struct error_condition
197  {
198    error_condition() noexcept
199    : _M_value(0), _M_cat(&generic_category()) { }
200
201    error_condition(int __v, const error_category& __cat) noexcept
202    : _M_value(__v), _M_cat(&__cat) { }
203
204    template<typename _ErrorConditionEnum, typename = typename
205	 enable_if<is_error_condition_enum<_ErrorConditionEnum>::value>::type>
206      error_condition(_ErrorConditionEnum __e) noexcept
207      { *this = make_error_condition(__e); }
208
209    void
210    assign(int __v, const error_category& __cat) noexcept
211    {
212      _M_value = __v;
213      _M_cat = &__cat;
214    }
215
216    // DR 804.
217    template<typename _ErrorConditionEnum>
218      typename enable_if<is_error_condition_enum
219			 <_ErrorConditionEnum>::value, error_condition&>::type
220      operator=(_ErrorConditionEnum __e) noexcept
221      { return *this = make_error_condition(__e); }
222
223    void
224    clear() noexcept
225    { assign(0, generic_category()); }
226
227    // 19.4.3.4 observers
228    int
229    value() const noexcept { return _M_value; }
230
231    const error_category&
232    category() const noexcept { return *_M_cat; }
233
234    string
235    message() const
236    { return category().message(value()); }
237
238    explicit operator bool() const noexcept
239    { return _M_value != 0 ? true : false; }
240
241    // DR 804.
242  private:
243    int 			_M_value;
244    const error_category* 	_M_cat;
245  };
246
247  // 19.4.3.6 non-member functions
248  inline error_condition
249  make_error_condition(errc __e) noexcept
250  { return error_condition(static_cast<int>(__e), generic_category()); }
251
252  inline bool
253  operator<(const error_condition& __lhs,
254	    const error_condition& __rhs) noexcept
255  {
256    return (__lhs.category() < __rhs.category()
257	    || (__lhs.category() == __rhs.category()
258		&& __lhs.value() < __rhs.value()));
259  }
260
261  // 19.4.4 Comparison operators
262  inline bool
263  operator==(const error_code& __lhs, const error_code& __rhs) noexcept
264  { return (__lhs.category() == __rhs.category()
265	    && __lhs.value() == __rhs.value()); }
266
267  inline bool
268  operator==(const error_code& __lhs, const error_condition& __rhs) noexcept
269  {
270    return (__lhs.category().equivalent(__lhs.value(), __rhs)
271	    || __rhs.category().equivalent(__lhs, __rhs.value()));
272  }
273
274  inline bool
275  operator==(const error_condition& __lhs, const error_code& __rhs) noexcept
276  {
277    return (__rhs.category().equivalent(__rhs.value(), __lhs)
278	    || __lhs.category().equivalent(__rhs, __lhs.value()));
279  }
280
281  inline bool
282  operator==(const error_condition& __lhs,
283	     const error_condition& __rhs) noexcept
284  {
285    return (__lhs.category() == __rhs.category()
286	    && __lhs.value() == __rhs.value());
287  }
288
289  inline bool
290  operator!=(const error_code& __lhs, const error_code& __rhs) noexcept
291  { return !(__lhs == __rhs); }
292
293  inline bool
294  operator!=(const error_code& __lhs, const error_condition& __rhs) noexcept
295  { return !(__lhs == __rhs); }
296
297  inline bool
298  operator!=(const error_condition& __lhs, const error_code& __rhs) noexcept
299  { return !(__lhs == __rhs); }
300
301  inline bool
302  operator!=(const error_condition& __lhs,
303	     const error_condition& __rhs) noexcept
304  { return !(__lhs == __rhs); }
305
306
307  /**
308   *  @brief Thrown to indicate error code of underlying system.
309   *
310   *  @ingroup exceptions
311   */
312  class system_error : public std::runtime_error
313  {
314  private:
315    error_code 	_M_code;
316
317  public:
318    system_error(error_code __ec = error_code())
319    : runtime_error(__ec.message()), _M_code(__ec) { }
320
321    system_error(error_code __ec, const string& __what)
322    : runtime_error(__what + ": " + __ec.message()), _M_code(__ec) { }
323
324    /*
325     * TODO: Add const char* ctors to all exceptions.
326     *
327     * system_error(error_code __ec, const char* __what)
328     * : runtime_error(__what + (": " + __ec.message())), _M_code(__ec) { }
329     *
330     * system_error(int __v, const error_category& __ecat, const char* __what)
331     * : runtime_error(__what + (": " + __ec.message())),
332     *   _M_code(error_code(__v, __ecat)) { }
333     */
334
335    system_error(int __v, const error_category& __ecat)
336    : runtime_error(error_code(__v, __ecat).message()),
337      _M_code(__v, __ecat) { }
338
339    system_error(int __v, const error_category& __ecat, const string& __what)
340    : runtime_error(__what + ": " + error_code(__v, __ecat).message()),
341      _M_code(__v, __ecat) { }
342
343    virtual ~system_error() noexcept;
344
345    const error_code&
346    code() const noexcept { return _M_code; }
347  };
348
349_GLIBCXX_END_NAMESPACE_VERSION
350} // namespace
351
352#ifndef _GLIBCXX_COMPATIBILITY_CXX0X
353
354#include <bits/functional_hash.h>
355
356namespace std _GLIBCXX_VISIBILITY(default)
357{
358_GLIBCXX_BEGIN_NAMESPACE_VERSION
359
360  // DR 1182.
361  /// std::hash specialization for error_code.
362  template<>
363    struct hash<error_code>
364    : public __hash_base<size_t, error_code>
365    {
366      size_t
367      operator()(const error_code& __e) const noexcept
368      {
369	const size_t __tmp = std::_Hash_impl::hash(__e._M_value);
370	return std::_Hash_impl::__hash_combine(__e._M_cat, __tmp);
371      }
372    };
373
374_GLIBCXX_END_NAMESPACE_VERSION
375} // namespace
376
377#endif // _GLIBCXX_COMPATIBILITY_CXX0X
378
379#endif // C++11
380
381#endif // _GLIBCXX_SYSTEM_ERROR
382