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Whole document tree                   codecvt.h Go to the documentation of this file. // Locale support (codecvt) -*- C++ -*- // Copyright (C) 2000, 2001 Free Software Foundation, Inc. // // This file is part of the GNU ISO C++ Library. This library is free // software; you can redistribute it and/or modify it under the // terms of the GNU General Public License as published by the // Free Software Foundation; either version 2, or (at your option) // any later version. // This library is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU General Public License for more details. // You should have received a copy of the GNU General Public License along // with this library; see the file COPYING. If not, write to the Free // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, // USA. // As a special exception, you may use this file as part of a free software // library without restriction. Specifically, if other files instantiate // templates or use macros or inline functions from this file, or you compile // this file and link it with other files to produce an executable, this // file does not by itself cause the resulting executable to be covered by // the GNU General Public License. This exception does not however // invalidate any other reasons why the executable file might be covered by // the GNU General Public License. // // ISO C++ 14882: 22.2.1.5 Template class codecvt // // Warning: this file is not meant for user inclusion. Use <locale>. // Written by Benjamin Kosnik <bkoz@cygnus.com> #ifndef _CPP_BITS_CODECVT_H #define _CPP_BITS_CODECVT_H 1 #pragma GCC system_header // XXX // __enc_traits may need to move up the locale header hierarchy, // depending on if ctype ends up using it. #ifdef _GLIBCPP_USE_WCHAR_T // Extensions to use icov for dealing with character encodings, // including conversions and comparisons between various character // sets. This object encapsulates data that may need to be shared between // char_traits, codecvt and ctype. #if _GLIBCPP_USE_SHADOW_HEADERS using _C_legacy::CODESET; #endif class __enc_traits { public: // Types: // NB: A conversion descriptor subsumes and enhances the // functionality of a simple state type such as mbstate_t. typedef iconv_t __desc_type; protected: // Data Members: // Max size of charset encoding name static const int _S_max_size = 32; // Name of internal character set encoding. char _M_int_enc[_S_max_size]; // Name of external character set encoding. char _M_ext_enc[_S_max_size]; // Conversion descriptor between external encoding to internal encoding. __desc_type _M_in_desc; // Conversion descriptor between internal encoding to external encoding. __desc_type _M_out_desc; // Details the byte-order marker for the external encoding, if necessary. int _M_ext_bom; // Details the byte-order marker for the internal encoding, if necessary. int _M_int_bom; public: __enc_traits() : _M_in_desc(0), _M_out_desc(0), _M_ext_bom(0), _M_int_bom(0) { // __intc_end = whatever we are using internally, which is // UCS4 (linux) // UCS2 == UNICODE (microsoft, java, aix, whatever...) // XXX Currently don't know how to get this data from target system... strcpy(_M_int_enc, "UCS4"); // __extc_end = external codeset in current locale strcpy(_M_ext_enc, nl_langinfo(CODESET)); } __enc_traits(const char* __int, const char* __ext, int __ibom = 0, int __ebom = 0) : _M_in_desc(0), _M_out_desc(0), _M_ext_bom(0), _M_int_bom(0) { strncpy(_M_int_enc, __int, _S_max_size); strncpy(_M_ext_enc, __ext, _S_max_size); } // 21.1.2 traits typedefs // p4 // typedef STATE_T state_type // requires: state_type shall meet the requirements of // CopyConstructible types (20.1.3) __enc_traits(const __enc_traits& __obj) { strncpy(_M_int_enc, __obj._M_int_enc, _S_max_size); strncpy(_M_ext_enc, __obj._M_ext_enc, _S_max_size); _M_ext_bom = __obj._M_ext_bom; _M_int_bom = __obj._M_int_bom; } ~__enc_traits() { iconv_close(_M_in_desc); iconv_close(_M_out_desc); } // Initializes void _M_init() { _M_in_desc = iconv_open(_M_int_enc, _M_ext_enc); _M_out_desc = iconv_open(_M_ext_enc, _M_int_enc); if (_M_out_desc == iconv_t(-1) || _M_in_desc == iconv_t(-1)) { // XXX Extended error checking. } } bool _M_good() { return _M_out_desc && _M_in_desc && _M_out_desc != iconv_t(-1) && _M_in_desc != iconv_t(-1); } const __desc_type* _M_get_in_descriptor() { return &_M_in_desc; } const __desc_type* _M_get_out_descriptor() { return &_M_out_desc; } const char* _M_get_internal_enc() { return _M_int_enc; } const char* _M_get_external_enc() { return _M_ext_enc; } int _M_get_external_bom() { return _M_ext_bom; } int _M_get_internal_bom() { return _M_int_bom; } }; #endif //_GLIBCPP_USE_WCHAR_T // 22.2.1.5 Template class codecvt class codecvt_base { public: enum result { ok, partial, error, noconv }; }; // Template class __codecvt_abstract_base // NB: An abstract base class that fills in the public inlines, so // that the specializations don't have to re-copy the public // interface. template<typename _InternT, typename _ExternT, typename _StateT> class __codecvt_abstract_base : public locale::facet, public codecvt_base { public: // Types: typedef codecvt_base::result result; typedef _InternT intern_type; typedef _ExternT extern_type; typedef _StateT state_type; // 22.2.1.5.1 codecvt members result out(state_type& __state, const intern_type* __from, const intern_type* __from_end, const intern_type*& __from_next, extern_type* __to, extern_type* __to_end, extern_type*& __to_next) const { return this->do_out(__state, __from, __from_end, __from_next, __to, __to_end, __to_next); } result unshift(state_type& __state, extern_type* __to, extern_type* __to_end, extern_type*& __to_next) const { return this->do_unshift(__state, __to,__to_end,__to_next); } result in(state_type& __state, const extern_type* __from, const extern_type* __from_end, const extern_type*& __from_next, intern_type* __to, intern_type* __to_end, intern_type*& __to_next) const { return this->do_in(__state, __from, __from_end, __from_next, __to, __to_end, __to_next); } int encoding() const throw() { return this->do_encoding(); } bool always_noconv() const throw() { return this->do_always_noconv(); } int length(const state_type& __state, const extern_type* __from, const extern_type* __end, size_t __max) const { return this->do_length(__state, __from, __end, __max); } int max_length() const throw() { return this->do_max_length(); } protected: explicit __codecvt_abstract_base(size_t __refs = 0) : locale::facet(__refs) { } virtual ~__codecvt_abstract_base() { } virtual result do_out(state_type& __state, const intern_type* __from, const intern_type* __from_end, const intern_type*& __from_next, extern_type* __to, extern_type* __to_end, extern_type*& __to_next) const = 0; virtual result do_unshift(state_type& __state, extern_type* __to, extern_type* __to_end, extern_type*& __to_next) const = 0; virtual result do_in(state_type& __state, const extern_type* __from, const extern_type* __from_end, const extern_type*& __from_next, intern_type* __to, intern_type* __to_end, intern_type*& __to_next) const = 0; virtual int do_encoding() const throw() = 0; virtual bool do_always_noconv() const throw() = 0; virtual int do_length(const state_type&, const extern_type* __from, const extern_type* __end, size_t __max) const = 0; virtual int do_max_length() const throw() = 0; }; // 22.2.1.5 Template class codecvt // NB: Generic, mostly useless implementation. template<typename _InternT, typename _ExternT, typename _StateT> class codecvt : public __codecvt_abstract_base<_InternT, _ExternT, _StateT> { public: // Types: typedef codecvt_base::result result; typedef _InternT intern_type; typedef _ExternT extern_type; typedef _StateT state_type; // Data Members: static locale::id id; explicit codecvt(size_t __refs = 0) : __codecvt_abstract_base<_InternT,_ExternT,_StateT> (__refs) { } protected: virtual ~codecvt() { } }; template<typename _InternT, typename _ExternT, typename _StateT> locale::id codecvt<_InternT, _ExternT, _StateT>::id; #ifdef _GLIBCPP_USE_WCHAR_T // partial specialization // This specialization takes advantage of iconv to provide code // conversions between a large number of character encodings. template<typename _InternT, typename _ExternT> class codecvt<_InternT, _ExternT, __enc_traits> : public __codecvt_abstract_base<_InternT, _ExternT, __enc_traits> { public: // Types: typedef codecvt_base::result result; typedef _InternT intern_type; typedef _ExternT extern_type; typedef __enc_traits state_type; typedef __enc_traits::__desc_type __desc_type; typedef __enc_traits __enc_type; // Data Members: static locale::id id; explicit codecvt(size_t __refs = 0) : __codecvt_abstract_base<intern_type, extern_type, state_type>(__refs) { } explicit codecvt(__enc_type* __enc, size_t __refs = 0) : __codecvt_abstract_base<intern_type, extern_type, state_type>(__refs) { } protected: virtual ~codecvt() { } virtual result do_out(state_type& __state, const intern_type* __from, const intern_type* __from_end, const intern_type*& __from_next, extern_type* __to, extern_type* __to_end, extern_type*& __to_next) const; virtual result do_unshift(state_type& __state, extern_type* __to, extern_type* __to_end, extern_type*& __to_next) const; virtual result do_in(state_type& __state, const extern_type* __from, const extern_type* __from_end, const extern_type*& __from_next, intern_type* __to, intern_type* __to_end, intern_type*& __to_next) const; virtual int do_encoding() const throw(); virtual bool do_always_noconv() const throw(); virtual int do_length(const state_type&, const extern_type* __from, const extern_type* __end, size_t __max) const; virtual int do_max_length() const throw(); }; template<typename _InternT, typename _ExternT> locale::id codecvt<_InternT, _ExternT, __enc_traits>::id; // This adaptor works around the signature problems of the second // argument to iconv(): SUSv2 and others use 'const char**', but glibc 2.2 // uses 'char**', which is what the standard is (apparently) due to use // in the future. Using this adaptor, g++ will do the work for us. template<typename _T> inline size_t __iconv_adaptor(size_t(*iconv_func)(iconv_t, _T, size_t*, char**, size_t*), iconv_t cd, char** inbuf, size_t* inbytesleft, char** outbuf, size_t* outbytesleft) { return iconv_func(cd, (_T)inbuf, inbytesleft, outbuf, outbytesleft); } template<typename _InternT, typename _ExternT> codecvt_base::result codecvt<_InternT, _ExternT, __enc_traits>:: do_out(state_type& __state, const intern_type* __from, const intern_type* __from_end, const intern_type*& __from_next, extern_type* __to, extern_type* __to_end, extern_type*& __to_next) const { result __ret = codecvt::error; if (__state._M_good()) { typedef state_type::__desc_type __desc_type; const __desc_type* __desc = __state._M_get_out_descriptor(); const size_t __fmultiple = sizeof(intern_type) / sizeof(char); size_t __flen = __fmultiple * (__from_end - __from); const size_t __tmultiple = sizeof(extern_type) / sizeof(char); size_t __tlen = __tmultiple * (__to_end - __to); // Argument list for iconv specifies a byte sequence. Thus, // all to/from arrays must be brutally casted to char*. char* __cto = reinterpret_cast<char*>(__to); char* __cfrom; size_t __conv; // Some encodings need a byte order marker as the first item // in the byte stream, to designate endian-ness. The default // value for the byte order marker is NULL, so if this is // the case, it's not necessary and we can just go on our // merry way. int __int_bom = __state._M_get_internal_bom(); if (__int_bom) { size_t __size = __from_end - __from; intern_type* __cfixed = static_cast<intern_type*>(__builtin_alloca(sizeof(intern_type) * (__size + 1))); __cfixed[0] = static_cast<intern_type>(__int_bom); char_traits<intern_type>::copy(__cfixed + 1, __from, __size); __cfrom = reinterpret_cast<char*>(__cfixed); __conv = __iconv_adaptor(iconv, *__desc, &__cfrom, &__flen, &__cto, &__tlen); } else { intern_type* __cfixed = const_cast<intern_type*>(__from); __cfrom = reinterpret_cast<char*>(__cfixed); __conv = __iconv_adaptor(iconv, *__desc, &__cfrom, &__flen, &__cto, &__tlen); } if (__conv != size_t(-1)) { __from_next = reinterpret_cast<const intern_type*>(__cfrom); __to_next = reinterpret_cast<extern_type*>(__cto); __ret = codecvt::ok; } else { if (__flen < static_cast<size_t>(__from_end - __from)) { __from_next = reinterpret_cast<const intern_type*>(__cfrom); __to_next = reinterpret_cast<extern_type*>(__cto); __ret = codecvt::partial; } else __ret = codecvt::error; } } return __ret; } template<typename _InternT, typename _ExternT> codecvt_base::result codecvt<_InternT, _ExternT, __enc_traits>:: do_unshift(state_type& __state, extern_type* __to, extern_type* __to_end, extern_type*& __to_next) const { result __ret = codecvt::error; if (__state._M_good()) { typedef state_type::__desc_type __desc_type; const __desc_type* __desc = __state._M_get_in_descriptor(); const size_t __tmultiple = sizeof(intern_type) / sizeof(char); size_t __tlen = __tmultiple * (__to_end - __to); // Argument list for iconv specifies a byte sequence. Thus, // all to/from arrays must be brutally casted to char*. char* __cto = reinterpret_cast<char*>(__to); size_t __conv = __iconv_adaptor(iconv,*__desc, NULL, NULL, &__cto, &__tlen); if (__conv != size_t(-1)) { __to_next = reinterpret_cast<extern_type*>(__cto); if (__tlen == __tmultiple * (__to_end - __to)) __ret = codecvt::noconv; else if (__tlen == 0) __ret = codecvt::ok; else __ret = codecvt::partial; } else __ret = codecvt::error; } return __ret; } template<typename _InternT, typename _ExternT> codecvt_base::result codecvt<_InternT, _ExternT, __enc_traits>:: do_in(state_type& __state, const extern_type* __from, const extern_type* __from_end, const extern_type*& __from_next, intern_type* __to, intern_type* __to_end, intern_type*& __to_next) const { result __ret = codecvt::error; if (__state._M_good()) { typedef state_type::__desc_type __desc_type; const __desc_type* __desc = __state._M_get_in_descriptor(); const size_t __fmultiple = sizeof(extern_type) / sizeof(char); size_t __flen = __fmultiple * (__from_end - __from); const size_t __tmultiple = sizeof(intern_type) / sizeof(char); size_t __tlen = __tmultiple * (__to_end - __to); // Argument list for iconv specifies a byte sequence. Thus, // all to/from arrays must be brutally casted to char*. char* __cto = reinterpret_cast<char*>(__to); char* __cfrom; size_t __conv; // Some encodings need a byte order marker as the first item // in the byte stream, to designate endian-ness. The default // value for the byte order marker is NULL, so if this is // the case, it's not necessary and we can just go on our // merry way. int __ext_bom = __state._M_get_external_bom(); if (__ext_bom) { size_t __size = __from_end - __from; extern_type* __cfixed = static_cast<extern_type*>(__builtin_alloca(sizeof(extern_type) * (__size + 1))); __cfixed[0] = static_cast<extern_type>(__ext_bom); char_traits<extern_type>::copy(__cfixed + 1, __from, __size); __cfrom = reinterpret_cast<char*>(__cfixed); __conv = __iconv_adaptor(iconv, *__desc, &__cfrom, &__flen, &__cto, &__tlen); } else { extern_type* __cfixed = const_cast<extern_type*>(__from); __cfrom = reinterpret_cast<char*>(__cfixed); __conv = __iconv_adaptor(iconv, *__desc, &__cfrom, &__flen, &__cto, &__tlen); } if (__conv != size_t(-1)) { __from_next = reinterpret_cast<const extern_type*>(__cfrom); __to_next = reinterpret_cast<intern_type*>(__cto); __ret = codecvt::ok; } else { if (__flen < static_cast<size_t>(__from_end - __from)) { __from_next = reinterpret_cast<const extern_type*>(__cfrom); __to_next = reinterpret_cast<intern_type*>(__cto); __ret = codecvt::partial; } else __ret = codecvt::error; } } return __ret; } template<typename _InternT, typename _ExternT> int codecvt<_InternT, _ExternT, __enc_traits>:: do_encoding() const throw() { return 0; } template<typename _InternT, typename _ExternT> bool codecvt<_InternT, _ExternT, __enc_traits>:: do_always_noconv() const throw() { return false; } template<typename _InternT, typename _ExternT> int codecvt<_InternT, _ExternT, __enc_traits>:: do_length(const state_type&, const extern_type* __from, const extern_type* __end, size_t __max) const { return min(__max, static_cast<size_t>(__end - __from)); } #ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS // 74. Garbled text for codecvt::do_max_length template<typename _InternT, typename _ExternT> int codecvt<_InternT, _ExternT, __enc_traits>:: do_max_length() const throw() { return 1; } #endif #endif /* _GLIBCPP_USE_WCHAR_T */ // codecvt<char, char, mbstate_t> required specialization template<> class codecvt<char, char, mbstate_t> : public __codecvt_abstract_base<char, char, mbstate_t> { public: // Types: typedef char intern_type; typedef char extern_type; typedef mbstate_t state_type; // Data Members: static locale::id id; explicit codecvt(size_t __refs = 0); protected: virtual ~codecvt(); virtual result do_out(state_type& __state, const intern_type* __from, const intern_type* __from_end, const intern_type*& __from_next, extern_type* __to, extern_type* __to_end, extern_type*& __to_next) const; virtual result do_unshift(state_type& __state, extern_type* __to, extern_type* __to_end, extern_type*& __to_next) const; virtual result do_in(state_type& __state, const extern_type* __from, const extern_type* __from_end, const extern_type*& __from_next, intern_type* __to, intern_type* __to_end, intern_type*& __to_next) const; virtual int do_encoding() const throw(); virtual bool do_always_noconv() const throw(); virtual int do_length(const state_type&, const extern_type* __from, const extern_type* __end, size_t __max) const; virtual int do_max_length() const throw(); }; #ifdef _GLIBCPP_USE_WCHAR_T // codecvt<wchar_t, char, mbstate_t> required specialization template<> class codecvt<wchar_t, char, mbstate_t> : public __codecvt_abstract_base<wchar_t, char, mbstate_t> { public: // Types: typedef wchar_t intern_type; typedef char extern_type; typedef mbstate_t state_type; // Data Members: static locale::id id; explicit codecvt(size_t __refs = 0); protected: virtual ~codecvt(); virtual result do_out(state_type& __state, const intern_type* __from, const intern_type* __from_end, const intern_type*& __from_next, extern_type* __to, extern_type* __to_end, extern_type*& __to_next) const; virtual result do_unshift(state_type& __state, extern_type* __to, extern_type* __to_end, extern_type*& __to_next) const; virtual result do_in(state_type& __state, const extern_type* __from, const extern_type* __from_end, const extern_type*& __from_next, intern_type* __to, intern_type* __to_end, intern_type*& __to_next) const; virtual int do_encoding() const throw(); virtual bool do_always_noconv() const throw(); virtual int do_length(const state_type&, const extern_type* __from, const extern_type* __end, size_t __max) const; virtual int do_max_length() const throw(); }; #endif //_GLIBCPP_USE_WCHAR_T // 22.2.1.6 Template class codecvt_byname template<typename _InternT, typename _ExternT, typename _StateT> class codecvt_byname : public codecvt<_InternT, _ExternT, _StateT> { public: explicit codecvt_byname(const char*, size_t __refs = 0) : codecvt<_InternT, _ExternT, _StateT>(__refs) { } protected: virtual ~codecvt_byname() { } }; #endif // _CPP_BITS_CODECVT_H // Local Variables: // mode:c++ // End: