1// <system_error> -*- C++ -*-
2
3// Copyright (C) 2007, 2008, 2009, 2010 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 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#ifndef __GXX_EXPERIMENTAL_CXX0X__
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
43_GLIBCXX_BEGIN_NAMESPACE(std)
44
45  class error_code;
46  class error_condition;
47  class error_category;
48  class system_error;
49
50  /// is_error_code_enum
51  template<typename _Tp>
52    struct is_error_code_enum : public false_type { };
53
54  /// is_error_condition_enum
55  template<typename _Tp>
56    struct is_error_condition_enum : public false_type { };
57
58  template<> 
59    struct is_error_condition_enum<errc>
60    : public true_type { };
61
62
63  /// error_category
64  class error_category
65  {
66  protected:
67    error_category();
68
69  public:
70    virtual ~error_category() { }
71
72    error_category(const error_category&) = delete;
73    error_category& operator=(const error_category&) = delete;
74
75    virtual const char* 
76    name() const = 0;
77
78    virtual string 
79    message(int) const = 0;
80
81    virtual error_condition
82    default_error_condition(int __i) const;
83
84    virtual bool 
85    equivalent(int __i, const error_condition& __cond) const;
86
87    virtual bool 
88    equivalent(const error_code& __code, int __i) const;
89
90    bool 
91    operator<(const error_category& __other) const
92    { return less<const error_category*>()(this, &__other); }
93
94    bool 
95    operator==(const error_category& __other) const
96    { return this == &__other; }
97
98    bool 
99    operator!=(const error_category& __other) const
100    { return this != &__other; }
101  };
102
103  inline error_category::error_category() = default;
104
105  // DR 890.
106  _GLIBCXX_CONST const error_category& system_category() throw();
107  _GLIBCXX_CONST const error_category& generic_category() throw();
108
109  error_code make_error_code(errc);
110
111  template<typename _Tp>
112    struct hash;
113
114  /// error_code
115  // Implementation-specific error identification
116  struct error_code
117  {
118    error_code()
119    : _M_value(0), _M_cat(&system_category()) { }
120
121    error_code(int __v, const error_category& __cat)
122    : _M_value(__v), _M_cat(&__cat) { }
123
124    template<typename _ErrorCodeEnum>
125      error_code(_ErrorCodeEnum __e,
126      typename enable_if<is_error_code_enum<_ErrorCodeEnum>::value>::type* = 0)
127      { *this = make_error_code(__e); }
128
129    void 
130    assign(int __v, const error_category& __cat)
131    {
132      _M_value = __v;
133      _M_cat = &__cat; 
134    }
135
136    void 
137    clear()
138    { assign(0, system_category()); }
139
140    // DR 804.
141    template<typename _ErrorCodeEnum>
142      typename enable_if<is_error_code_enum<_ErrorCodeEnum>::value,
143			 error_code&>::type
144      operator=(_ErrorCodeEnum __e)
145      { return *this = make_error_code(__e); }
146
147    int
148    value() const { return _M_value; }
149      
150    const error_category&  
151    category() const { return *_M_cat; }
152
153    error_condition 
154    default_error_condition() const;
155
156    string 
157    message() const
158    { return category().message(value()); }
159
160    explicit operator bool() const
161    { return _M_value != 0 ? true : false; }
162
163    // DR 804.
164  private:
165    friend class hash<error_code>;
166
167    int            		_M_value;
168    const error_category* 	_M_cat;
169  };
170
171  // 19.4.2.6 non-member functions
172  inline error_code
173  make_error_code(errc __e)
174  { return error_code(static_cast<int>(__e), generic_category()); }
175
176  inline bool
177  operator<(const error_code& __lhs, const error_code& __rhs)
178  { 
179    return (__lhs.category() < __rhs.category()
180	    || (__lhs.category() == __rhs.category()
181		&& __lhs.value() < __rhs.value()));
182  }
183
184  template<typename _CharT, typename _Traits>
185    basic_ostream<_CharT, _Traits>&
186    operator<<(basic_ostream<_CharT, _Traits>& __os, const error_code& __e)
187    { return (__os << __e.category().name() << ':' << __e.value()); }
188
189  error_condition make_error_condition(errc);
190
191  /// error_condition
192  // Portable error identification
193  struct error_condition 
194  {
195    error_condition()
196    : _M_value(0), _M_cat(&generic_category()) { }
197
198    error_condition(int __v, const error_category& __cat)     
199    : _M_value(__v), _M_cat(&__cat) { }
200
201    template<typename _ErrorConditionEnum>
202      error_condition(_ErrorConditionEnum __e,
203		      typename enable_if<is_error_condition_enum
204		                      <_ErrorConditionEnum>::value>::type* = 0)
205      { *this = make_error_condition(__e); }
206
207    void
208    assign(int __v, const error_category& __cat)
209    {
210      _M_value = __v;
211      _M_cat = &__cat;
212    }
213
214    // DR 804.
215    template<typename _ErrorConditionEnum>
216      typename enable_if<is_error_condition_enum
217			 <_ErrorConditionEnum>::value, error_condition&>::type
218      operator=(_ErrorConditionEnum __e)
219      { return *this = make_error_condition(__e); }
220
221    void 
222    clear()
223    { assign(0, generic_category()); }
224
225    // 19.4.3.4 observers
226    int 
227    value() const { return _M_value; }
228
229    const error_category&
230    category() const { return *_M_cat; }
231
232    string 
233    message() const
234    { return category().message(value()); }
235
236    explicit operator bool() const
237    { return _M_value != 0 ? true : false; }
238
239    // DR 804.
240  private:
241    int 			_M_value;
242    const error_category* 	_M_cat;
243  };
244
245  // 19.4.3.6 non-member functions
246  inline error_condition
247  make_error_condition(errc __e)
248  { return error_condition(static_cast<int>(__e), generic_category()); }
249
250  inline bool 
251  operator<(const error_condition& __lhs, const error_condition& __rhs)
252  {
253    return (__lhs.category() < __rhs.category()
254	    || (__lhs.category() == __rhs.category()
255		&& __lhs.value() < __rhs.value()));
256  }
257
258  // 19.4.4 Comparison operators
259  inline bool
260  operator==(const error_code& __lhs, const error_code& __rhs)
261  { return (__lhs.category() == __rhs.category()
262	    && __lhs.value() == __rhs.value()); }
263
264  inline bool
265  operator==(const error_code& __lhs, const error_condition& __rhs)
266  {
267    return (__lhs.category().equivalent(__lhs.value(), __rhs)
268	    || __rhs.category().equivalent(__lhs, __rhs.value()));
269  }
270
271  inline bool
272  operator==(const error_condition& __lhs, const error_code& __rhs)
273  {
274    return (__rhs.category().equivalent(__rhs.value(), __lhs)
275	    || __lhs.category().equivalent(__rhs, __lhs.value()));
276  }
277
278  inline bool
279  operator==(const error_condition& __lhs, const error_condition& __rhs)
280  {
281    return (__lhs.category() == __rhs.category()
282	    && __lhs.value() == __rhs.value());
283  }
284
285  inline bool
286  operator!=(const error_code& __lhs, const error_code& __rhs)
287  { return !(__lhs == __rhs); }
288
289  inline bool
290  operator!=(const error_code& __lhs, const error_condition& __rhs)
291  { return !(__lhs == __rhs); }
292
293  inline bool
294  operator!=(const error_condition& __lhs, const error_code& __rhs)
295  { return !(__lhs == __rhs); }
296
297  inline bool
298  operator!=(const error_condition& __lhs, const error_condition& __rhs)
299  { return !(__lhs == __rhs); }
300
301
302  /** 
303   *  @brief Thrown to indicate error code of underlying system.
304   *
305   *  @ingroup exceptions
306   */
307  class system_error : public std::runtime_error
308  {
309  private:
310    error_code 	_M_code;
311
312  public:
313    system_error(error_code __ec = error_code())
314    : runtime_error(""), _M_code(__ec) { }
315
316    system_error(error_code __ec, const string& __what)
317    : runtime_error(__what), _M_code(__ec) { }
318    
319    /*
320     * TODO: Add const char* ctors to all exceptions.
321     *
322     * system_error(error_code __ec, const char* __what)
323     * : runtime_error(__what), _M_code(__ec) { }
324     *
325     * system_error(int __v, const error_category& __ecat, const char* __what)
326     * : runtime_error(__what), _M_code(error_code(__v, __ecat)) { }
327     */
328
329    system_error(int __v, const error_category& __ecat)
330    : runtime_error(""), _M_code(error_code(__v, __ecat)) { }
331
332    system_error(int __v, const error_category& __ecat, const string& __what)
333    : runtime_error(__what), _M_code(error_code(__v, __ecat)) { }
334
335    virtual ~system_error() throw();
336
337    const error_code& 
338    code() const throw() { return _M_code; }
339  };
340
341_GLIBCXX_END_NAMESPACE
342
343#ifndef _GLIBCXX_COMPATIBILITY_CXX0X
344
345#include <bits/functional_hash.h>
346
347_GLIBCXX_BEGIN_NAMESPACE(std)
348
349  // DR 1182.
350  /// std::hash specialization for error_code.
351  template<>
352    struct hash<error_code>
353    : public std::unary_function<error_code, size_t>
354    {
355      size_t
356      operator()(const error_code& __e) const
357      {
358	const size_t __tmp = std::_Fnv_hash::hash(__e._M_value);
359	return std::_Fnv_hash::__hash_combine(__e._M_cat, __tmp);
360      }
361    };
362
363_GLIBCXX_END_NAMESPACE
364
365#endif // _GLIBCXX_COMPATIBILITY_CXX0X
366
367#endif // __GXX_EXPERIMENTAL_CXX0X__
368
369#endif // _GLIBCXX_SYSTEM_ERROR
370
371