Subversion Repositories scarts

// Locale support (codecvt) -*- C++ -*-

// Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005

//  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, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,

// 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

//

// Written by Benjamin Kosnik <bkoz@redhat.com>

/** @file bits/codecvt_specializations.h

 *  This file is a GNU extension to the Standard C++ Library.

 */

  // XXX

  // Define this here so codecvt.cc can have _S_max_size definition.

#define _GLIBCXX_USE_ENCODING_STATE 1

namespace __gnu_cxx

{

  /// @brief  Extension to use icov for dealing with character encodings.

  // This includes conversions and comparisons between various character

  // sets.  This object encapsulates data that may need to be shared between

  // char_traits, codecvt and ctype.

  class encoding_state

  {

  public:

    // Types: 

    // NB: A conversion descriptor subsumes and enhances the

    // functionality of a simple state type such as mbstate_t.

    typedef iconv_t     descriptor_type;

  protected:

    // Name of internal character set encoding.

    std::string         _M_int_enc;

    // Name of external character set encoding.

    std::string         _M_ext_enc;

    // Conversion descriptor between external encoding to internal encoding.

    descriptor_type     _M_in_desc;

    // Conversion descriptor between internal encoding to external encoding.

    descriptor_type     _M_out_desc;

    // The byte-order marker for the external encoding, if necessary.

    int                 _M_ext_bom;

    // The byte-order marker for the internal encoding, if necessary.

    int                 _M_int_bom;

    // Number of external bytes needed to construct one complete

    // character in the internal encoding.

    // NB: -1 indicates variable, or stateful, encodings.

    int                 _M_bytes;

  public:

    explicit

    encoding_state()

    : _M_in_desc(0), _M_out_desc(0), _M_ext_bom(0), _M_int_bom(0), _M_bytes(0)

    { }

    explicit

    encoding_state(const char* __int, const char* __ext,

                   int __ibom = 0, int __ebom = 0, int __bytes = 1)

    : _M_int_enc(__int), _M_ext_enc(__ext), _M_in_desc(0), _M_out_desc(0),

      _M_ext_bom(__ebom), _M_int_bom(__ibom), _M_bytes(__bytes)

    { init(); }

    // 21.1.2 traits typedefs

    // p4

    // typedef STATE_T state_type

    // requires: state_type shall meet the requirements of

    // CopyConstructible types (20.1.3)

    // NB: This does not preseve the actual state of the conversion

    // descriptor member, but it does duplicate the encoding

    // information.

    encoding_state(const encoding_state& __obj) : _M_in_desc(0), _M_out_desc(0)

    { construct(__obj); }

    // Need assignment operator as well.

    encoding_state&

    operator=(const encoding_state& __obj)

    {

      construct(__obj);

      return *this;

    }

    ~encoding_state()

    { destroy(); }

    bool

    good() const throw()

    {

      const descriptor_type __err = reinterpret_cast<iconv_t>(-1);

      bool __test = _M_in_desc && _M_in_desc != __err;

      __test &=  _M_out_desc && _M_out_desc != __err;

      return __test;

    }

    int

    character_ratio() const

    { return _M_bytes; }

    const std::string

    internal_encoding() const

    { return _M_int_enc; }

    int

    internal_bom() const

    { return _M_int_bom; }

    const std::string

    external_encoding() const

    { return _M_ext_enc; }

    int

    external_bom() const

    { return _M_ext_bom; }

    const descriptor_type&

    in_descriptor() const

    { return _M_in_desc; }

    const descriptor_type&

    out_descriptor() const

    { return _M_out_desc; }

  protected:

    void

    init()

    {

      const descriptor_type __err = reinterpret_cast<iconv_t>(-1);

      const bool __have_encodings = _M_int_enc.size() && _M_ext_enc.size();

      if (!_M_in_desc && __have_encodings)

        {

          _M_in_desc = iconv_open(_M_int_enc.c_str(), _M_ext_enc.c_str());

          if (_M_in_desc == __err)

            std::__throw_runtime_error(__N("encoding_state::_M_init "

                                    "creating iconv input descriptor failed"));

        }

      if (!_M_out_desc && __have_encodings)

        {

          _M_out_desc = iconv_open(_M_ext_enc.c_str(), _M_int_enc.c_str());

          if (_M_out_desc == __err)

            std::__throw_runtime_error(__N("encoding_state::_M_init "

                                  "creating iconv output descriptor failed"));

        }

    }

    void

    construct(const encoding_state& __obj)

    {

      destroy();

      _M_int_enc = __obj._M_int_enc;

      _M_ext_enc = __obj._M_ext_enc;

      _M_ext_bom = __obj._M_ext_bom;

      _M_int_bom = __obj._M_int_bom;

      _M_bytes = __obj._M_bytes;

      init();

    }

    void

    destroy() throw()

    {

      const descriptor_type __err = reinterpret_cast<iconv_t>(-1);

      if (_M_in_desc && _M_in_desc != __err)

        {

          iconv_close(_M_in_desc);

          _M_in_desc = 0;

        }

      if (_M_out_desc && _M_out_desc != __err)

        {

          iconv_close(_M_out_desc);

          _M_out_desc = 0;

        }

    }

  };

  /// @brief  encoding_char_traits.

  // Custom traits type with encoding_state for the state type, and the

  // associated fpos<encoding_state> for the position type, all other

  // bits equivalent to the required char_traits instantiations.

  template<typename _CharT>

    struct encoding_char_traits : public std::char_traits<_CharT>

    {

      typedef encoding_state                            state_type;

      typedef typename std::fpos<state_type>            pos_type;

    };

} // namespace __gnu_cxx

namespace std

{

  using __gnu_cxx::encoding_state;

  /// @brief  codecvt<InternT, _ExternT, encoding_state> specialization.

  // This partial 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, encoding_state>

    : public __codecvt_abstract_base<_InternT, _ExternT, encoding_state>

    {

    public:

      // Types:

      typedef codecvt_base::result                      result;

      typedef _InternT                                  intern_type;

      typedef _ExternT                                  extern_type;

      typedef __gnu_cxx::encoding_state                 state_type;

      typedef state_type::descriptor_type               descriptor_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(state_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(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, encoding_state>::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 matches the POSIX 1003.1-2001 standard.

  // Using this adaptor, g++ will do the work for us.

  template<typename _T>

    inline size_t

    __iconv_adaptor(size_t(*__func)(iconv_t, _T, size_t*, char**, size_t*),

                    iconv_t __cd, char** __inbuf, size_t* __inbytes,

                    char** __outbuf, size_t* __outbytes)

    { return __func(__cd, (_T)__inbuf, __inbytes, __outbuf, __outbytes); }

  template<typename _InternT, typename _ExternT>

    codecvt_base::result

    codecvt<_InternT, _ExternT, encoding_state>::

    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_base::error;

      if (__state.good())

        {

          const descriptor_type& __desc = __state.out_descriptor();

          const size_t __fmultiple = sizeof(intern_type);

          size_t __fbytes = __fmultiple * (__from_end - __from);

          const size_t __tmultiple = sizeof(extern_type);

          size_t __tbytes = __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.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,

                                        &__fbytes, &__cto, &__tbytes);

            }

          else

            {

              intern_type* __cfixed = const_cast<intern_type*>(__from);

              __cfrom = reinterpret_cast<char*>(__cfixed);

              __conv = __iconv_adaptor(iconv, __desc, &__cfrom, &__fbytes,

                                       &__cto, &__tbytes);

            }

          if (__conv != size_t(-1))

            {

              __from_next = reinterpret_cast<const intern_type*>(__cfrom);

              __to_next = reinterpret_cast<extern_type*>(__cto);

              __ret = codecvt_base::ok;

            }

          else

            {

              if (__fbytes < __fmultiple * (__from_end - __from))

                {

                  __from_next = reinterpret_cast<const intern_type*>(__cfrom);

                  __to_next = reinterpret_cast<extern_type*>(__cto);

                  __ret = codecvt_base::partial;

                }

              else

                __ret = codecvt_base::error;

            }

        }

      return __ret;

    }

  template<typename _InternT, typename _ExternT>

    codecvt_base::result

    codecvt<_InternT, _ExternT, encoding_state>::

    do_unshift(state_type& __state, extern_type* __to,

               extern_type* __to_end, extern_type*& __to_next) const

    {

      result __ret = codecvt_base::error;

      if (__state.good())

        {

          const descriptor_type& __desc = __state.in_descriptor();

          const size_t __tmultiple = sizeof(intern_type);

          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_base::noconv;

              else if (__tlen == 0)

                __ret = codecvt_base::ok;

              else

                __ret = codecvt_base::partial;

            }

          else

            __ret = codecvt_base::error;

        }

      return __ret;

    }

  template<typename _InternT, typename _ExternT>

    codecvt_base::result

    codecvt<_InternT, _ExternT, encoding_state>::

    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_base::error;

      if (__state.good())

        {

          const descriptor_type& __desc = __state.in_descriptor();

          const size_t __fmultiple = sizeof(extern_type);

          size_t __flen = __fmultiple * (__from_end - __from);

          const size_t __tmultiple = sizeof(intern_type);

          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.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_base::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_base::partial;

                }

              else

                __ret = codecvt_base::error;

            }

        }

      return __ret;

    }

  template<typename _InternT, typename _ExternT>

    int

    codecvt<_InternT, _ExternT, encoding_state>::

    do_encoding() const throw()

    {

      int __ret = 0;

      if (sizeof(_ExternT) <= sizeof(_InternT))

        __ret = sizeof(_InternT) / sizeof(_ExternT);

      return __ret;

    }

  template<typename _InternT, typename _ExternT>

    bool

    codecvt<_InternT, _ExternT, encoding_state>::

    do_always_noconv() const throw()

    { return false; }

  template<typename _InternT, typename _ExternT>

    int

    codecvt<_InternT, _ExternT, encoding_state>::

    do_length(state_type&, const extern_type* __from,

              const extern_type* __end, size_t __max) const

    { return std::min(__max, static_cast<size_t>(__end - __from)); }

  // _GLIBCXX_RESOLVE_LIB_DEFECTS

  // 74.  Garbled text for codecvt::do_max_length

  template<typename _InternT, typename _ExternT>

    int

    codecvt<_InternT, _ExternT, encoding_state>::

    do_max_length() const throw()

    { return 1; }

} // namespace std