1 // Locale support (codecvt) -*- C++ -*-
3 // Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2009
4 // Free Software Foundation, Inc.
6 // This file is part of the GNU ISO C++ Library. This library is free
7 // software; you can redistribute it and/or modify it under the
8 // terms of the GNU General Public License as published by the
9 // Free Software Foundation; either version 3, or (at your option)
12 // This library is distributed in the hope that it will be useful,
13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 // GNU General Public License for more details.
17 // Under Section 7 of GPL version 3, you are granted additional
18 // permissions described in the GCC Runtime Library Exception, version
19 // 3.1, as published by the Free Software Foundation.
21 // You should have received a copy of the GNU General Public License and
22 // a copy of the GCC Runtime Library Exception along with this program;
23 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
24 // <http://www.gnu.org/licenses/>.
27 // ISO C++ 14882: 22.2.1.5 Template class codecvt
30 // Written by Benjamin Kosnik <bkoz@redhat.com>
32 /** @file ext/codecvt_specializations.h
33 * This file is a GNU extension to the Standard C++ Library.
36 #ifndef _EXT_CODECVT_SPECIALIZATIONS_H
37 #define _EXT_CODECVT_SPECIALIZATIONS_H 1
39 #include <bits/c++config.h>
43 _GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)
45 /// Extension to use iconv for dealing with character encodings.
46 // This includes conversions and comparisons between various character
47 // sets. This object encapsulates data that may need to be shared between
48 // char_traits, codecvt and ctype.
53 // NB: A conversion descriptor subsumes and enhances the
54 // functionality of a simple state type such as mbstate_t.
55 typedef iconv_t descriptor_type;
58 // Name of internal character set encoding.
59 std::string _M_int_enc;
61 // Name of external character set encoding.
62 std::string _M_ext_enc;
64 // Conversion descriptor between external encoding to internal encoding.
65 descriptor_type _M_in_desc;
67 // Conversion descriptor between internal encoding to external encoding.
68 descriptor_type _M_out_desc;
70 // The byte-order marker for the external encoding, if necessary.
73 // The byte-order marker for the internal encoding, if necessary.
76 // Number of external bytes needed to construct one complete
77 // character in the internal encoding.
78 // NB: -1 indicates variable, or stateful, encodings.
84 : _M_in_desc(0), _M_out_desc(0), _M_ext_bom(0), _M_int_bom(0), _M_bytes(0)
88 encoding_state(const char* __int, const char* __ext,
89 int __ibom = 0, int __ebom = 0, int __bytes = 1)
90 : _M_int_enc(__int), _M_ext_enc(__ext), _M_in_desc(0), _M_out_desc(0),
91 _M_ext_bom(__ebom), _M_int_bom(__ibom), _M_bytes(__bytes)
94 // 21.1.2 traits typedefs
96 // typedef STATE_T state_type
97 // requires: state_type shall meet the requirements of
98 // CopyConstructible types (20.1.3)
99 // NB: This does not preserve the actual state of the conversion
100 // descriptor member, but it does duplicate the encoding
102 encoding_state(const encoding_state& __obj) : _M_in_desc(0), _M_out_desc(0)
103 { construct(__obj); }
105 // Need assignment operator as well.
107 operator=(const encoding_state& __obj)
119 const descriptor_type __err = (iconv_t)(-1);
120 bool __test = _M_in_desc && _M_in_desc != __err;
121 __test &= _M_out_desc && _M_out_desc != __err;
126 character_ratio() const
130 internal_encoding() const
131 { return _M_int_enc; }
135 { return _M_int_bom; }
138 external_encoding() const
139 { return _M_ext_enc; }
143 { return _M_ext_bom; }
145 const descriptor_type&
146 in_descriptor() const
147 { return _M_in_desc; }
149 const descriptor_type&
150 out_descriptor() const
151 { return _M_out_desc; }
157 const descriptor_type __err = (iconv_t)(-1);
158 const bool __have_encodings = _M_int_enc.size() && _M_ext_enc.size();
159 if (!_M_in_desc && __have_encodings)
161 _M_in_desc = iconv_open(_M_int_enc.c_str(), _M_ext_enc.c_str());
162 if (_M_in_desc == __err)
163 std::__throw_runtime_error(__N("encoding_state::_M_init "
164 "creating iconv input descriptor failed"));
166 if (!_M_out_desc && __have_encodings)
168 _M_out_desc = iconv_open(_M_ext_enc.c_str(), _M_int_enc.c_str());
169 if (_M_out_desc == __err)
170 std::__throw_runtime_error(__N("encoding_state::_M_init "
171 "creating iconv output descriptor failed"));
176 construct(const encoding_state& __obj)
179 _M_int_enc = __obj._M_int_enc;
180 _M_ext_enc = __obj._M_ext_enc;
181 _M_ext_bom = __obj._M_ext_bom;
182 _M_int_bom = __obj._M_int_bom;
183 _M_bytes = __obj._M_bytes;
190 const descriptor_type __err = (iconv_t)(-1);
191 if (_M_in_desc && _M_in_desc != __err)
193 iconv_close(_M_in_desc);
196 if (_M_out_desc && _M_out_desc != __err)
198 iconv_close(_M_out_desc);
204 /// encoding_char_traits
205 // Custom traits type with encoding_state for the state type, and the
206 // associated fpos<encoding_state> for the position type, all other
207 // bits equivalent to the required char_traits instantiations.
208 template<typename _CharT>
209 struct encoding_char_traits : public std::char_traits<_CharT>
211 typedef encoding_state state_type;
212 typedef typename std::fpos<state_type> pos_type;
215 _GLIBCXX_END_NAMESPACE
218 _GLIBCXX_BEGIN_NAMESPACE(std)
220 using __gnu_cxx::encoding_state;
222 /// codecvt<InternT, _ExternT, encoding_state> specialization.
223 // This partial specialization takes advantage of iconv to provide
224 // code conversions between a large number of character encodings.
225 template<typename _InternT, typename _ExternT>
226 class codecvt<_InternT, _ExternT, encoding_state>
227 : public __codecvt_abstract_base<_InternT, _ExternT, encoding_state>
231 typedef codecvt_base::result result;
232 typedef _InternT intern_type;
233 typedef _ExternT extern_type;
234 typedef __gnu_cxx::encoding_state state_type;
235 typedef state_type::descriptor_type descriptor_type;
238 static locale::id id;
241 codecvt(size_t __refs = 0)
242 : __codecvt_abstract_base<intern_type, extern_type, state_type>(__refs)
246 codecvt(state_type& __enc, size_t __refs = 0)
247 : __codecvt_abstract_base<intern_type, extern_type, state_type>(__refs)
255 do_out(state_type& __state, const intern_type* __from,
256 const intern_type* __from_end, const intern_type*& __from_next,
257 extern_type* __to, extern_type* __to_end,
258 extern_type*& __to_next) const;
261 do_unshift(state_type& __state, extern_type* __to,
262 extern_type* __to_end, extern_type*& __to_next) const;
265 do_in(state_type& __state, const extern_type* __from,
266 const extern_type* __from_end, const extern_type*& __from_next,
267 intern_type* __to, intern_type* __to_end,
268 intern_type*& __to_next) const;
271 do_encoding() const throw();
274 do_always_noconv() const throw();
277 do_length(state_type&, const extern_type* __from,
278 const extern_type* __end, size_t __max) const;
281 do_max_length() const throw();
284 template<typename _InternT, typename _ExternT>
286 codecvt<_InternT, _ExternT, encoding_state>::id;
288 // This adaptor works around the signature problems of the second
289 // argument to iconv(): SUSv2 and others use 'const char**', but glibc 2.2
290 // uses 'char**', which matches the POSIX 1003.1-2001 standard.
291 // Using this adaptor, g++ will do the work for us.
292 template<typename _Tp>
294 __iconv_adaptor(size_t(*__func)(iconv_t, _Tp, size_t*, char**, size_t*),
295 iconv_t __cd, char** __inbuf, size_t* __inbytes,
296 char** __outbuf, size_t* __outbytes)
297 { return __func(__cd, (_Tp)__inbuf, __inbytes, __outbuf, __outbytes); }
299 template<typename _InternT, typename _ExternT>
301 codecvt<_InternT, _ExternT, encoding_state>::
302 do_out(state_type& __state, const intern_type* __from,
303 const intern_type* __from_end, const intern_type*& __from_next,
304 extern_type* __to, extern_type* __to_end,
305 extern_type*& __to_next) const
307 result __ret = codecvt_base::error;
310 const descriptor_type& __desc = __state.out_descriptor();
311 const size_t __fmultiple = sizeof(intern_type);
312 size_t __fbytes = __fmultiple * (__from_end - __from);
313 const size_t __tmultiple = sizeof(extern_type);
314 size_t __tbytes = __tmultiple * (__to_end - __to);
316 // Argument list for iconv specifies a byte sequence. Thus,
317 // all to/from arrays must be brutally casted to char*.
318 char* __cto = reinterpret_cast<char*>(__to);
322 // Some encodings need a byte order marker as the first item
323 // in the byte stream, to designate endian-ness. The default
324 // value for the byte order marker is NULL, so if this is
325 // the case, it's not necessary and we can just go on our
327 int __int_bom = __state.internal_bom();
330 size_t __size = __from_end - __from;
331 intern_type* __cfixed = static_cast<intern_type*>
332 (__builtin_alloca(sizeof(intern_type) * (__size + 1)));
333 __cfixed[0] = static_cast<intern_type>(__int_bom);
334 char_traits<intern_type>::copy(__cfixed + 1, __from, __size);
335 __cfrom = reinterpret_cast<char*>(__cfixed);
336 __conv = __iconv_adaptor(iconv, __desc, &__cfrom,
337 &__fbytes, &__cto, &__tbytes);
341 intern_type* __cfixed = const_cast<intern_type*>(__from);
342 __cfrom = reinterpret_cast<char*>(__cfixed);
343 __conv = __iconv_adaptor(iconv, __desc, &__cfrom, &__fbytes,
347 if (__conv != size_t(-1))
349 __from_next = reinterpret_cast<const intern_type*>(__cfrom);
350 __to_next = reinterpret_cast<extern_type*>(__cto);
351 __ret = codecvt_base::ok;
355 if (__fbytes < __fmultiple * (__from_end - __from))
357 __from_next = reinterpret_cast<const intern_type*>(__cfrom);
358 __to_next = reinterpret_cast<extern_type*>(__cto);
359 __ret = codecvt_base::partial;
362 __ret = codecvt_base::error;
368 template<typename _InternT, typename _ExternT>
370 codecvt<_InternT, _ExternT, encoding_state>::
371 do_unshift(state_type& __state, extern_type* __to,
372 extern_type* __to_end, extern_type*& __to_next) const
374 result __ret = codecvt_base::error;
377 const descriptor_type& __desc = __state.in_descriptor();
378 const size_t __tmultiple = sizeof(intern_type);
379 size_t __tlen = __tmultiple * (__to_end - __to);
381 // Argument list for iconv specifies a byte sequence. Thus,
382 // all to/from arrays must be brutally casted to char*.
383 char* __cto = reinterpret_cast<char*>(__to);
384 size_t __conv = __iconv_adaptor(iconv,__desc, NULL, NULL,
387 if (__conv != size_t(-1))
389 __to_next = reinterpret_cast<extern_type*>(__cto);
390 if (__tlen == __tmultiple * (__to_end - __to))
391 __ret = codecvt_base::noconv;
392 else if (__tlen == 0)
393 __ret = codecvt_base::ok;
395 __ret = codecvt_base::partial;
398 __ret = codecvt_base::error;
403 template<typename _InternT, typename _ExternT>
405 codecvt<_InternT, _ExternT, encoding_state>::
406 do_in(state_type& __state, const extern_type* __from,
407 const extern_type* __from_end, const extern_type*& __from_next,
408 intern_type* __to, intern_type* __to_end,
409 intern_type*& __to_next) const
411 result __ret = codecvt_base::error;
414 const descriptor_type& __desc = __state.in_descriptor();
415 const size_t __fmultiple = sizeof(extern_type);
416 size_t __flen = __fmultiple * (__from_end - __from);
417 const size_t __tmultiple = sizeof(intern_type);
418 size_t __tlen = __tmultiple * (__to_end - __to);
420 // Argument list for iconv specifies a byte sequence. Thus,
421 // all to/from arrays must be brutally casted to char*.
422 char* __cto = reinterpret_cast<char*>(__to);
426 // Some encodings need a byte order marker as the first item
427 // in the byte stream, to designate endian-ness. The default
428 // value for the byte order marker is NULL, so if this is
429 // the case, it's not necessary and we can just go on our
431 int __ext_bom = __state.external_bom();
434 size_t __size = __from_end - __from;
435 extern_type* __cfixed = static_cast<extern_type*>
436 (__builtin_alloca(sizeof(extern_type) * (__size + 1)));
437 __cfixed[0] = static_cast<extern_type>(__ext_bom);
438 char_traits<extern_type>::copy(__cfixed + 1, __from, __size);
439 __cfrom = reinterpret_cast<char*>(__cfixed);
440 __conv = __iconv_adaptor(iconv, __desc, &__cfrom,
441 &__flen, &__cto, &__tlen);
445 extern_type* __cfixed = const_cast<extern_type*>(__from);
446 __cfrom = reinterpret_cast<char*>(__cfixed);
447 __conv = __iconv_adaptor(iconv, __desc, &__cfrom,
448 &__flen, &__cto, &__tlen);
452 if (__conv != size_t(-1))
454 __from_next = reinterpret_cast<const extern_type*>(__cfrom);
455 __to_next = reinterpret_cast<intern_type*>(__cto);
456 __ret = codecvt_base::ok;
460 if (__flen < static_cast<size_t>(__from_end - __from))
462 __from_next = reinterpret_cast<const extern_type*>(__cfrom);
463 __to_next = reinterpret_cast<intern_type*>(__cto);
464 __ret = codecvt_base::partial;
467 __ret = codecvt_base::error;
473 template<typename _InternT, typename _ExternT>
475 codecvt<_InternT, _ExternT, encoding_state>::
476 do_encoding() const throw()
479 if (sizeof(_ExternT) <= sizeof(_InternT))
480 __ret = sizeof(_InternT) / sizeof(_ExternT);
484 template<typename _InternT, typename _ExternT>
486 codecvt<_InternT, _ExternT, encoding_state>::
487 do_always_noconv() const throw()
490 template<typename _InternT, typename _ExternT>
492 codecvt<_InternT, _ExternT, encoding_state>::
493 do_length(state_type&, const extern_type* __from,
494 const extern_type* __end, size_t __max) const
495 { return std::min(__max, static_cast<size_t>(__end - __from)); }
497 // _GLIBCXX_RESOLVE_LIB_DEFECTS
498 // 74. Garbled text for codecvt::do_max_length
499 template<typename _InternT, typename _ExternT>
501 codecvt<_InternT, _ExternT, encoding_state>::
502 do_max_length() const throw()
505 _GLIBCXX_END_NAMESPACE