1  /* Case mapping of a 32-bit wide character.
       2     Copyright (C) 2020-2023 Free Software Foundation, Inc.
       3  
       4     This file is free software: you can redistribute it and/or modify
       5     it under the terms of the GNU Lesser General Public License as
       6     published by the Free Software Foundation; either version 2.1 of the
       7     License, or (at your option) any later version.
       8  
       9     This file is distributed in the hope that it will be useful,
      10     but WITHOUT ANY WARRANTY; without even the implied warranty of
      11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      12     GNU Lesser General Public License for more details.
      13  
      14     You should have received a copy of the GNU Lesser General Public License
      15     along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
      16  
      17  /* Written by Bruno Haible <bruno@clisp.org>, 2023.  */
      18  
      19  #include <wchar.h>
      20  #include <wctype.h>
      21  
      22  #if GNULIB_defined_mbstate_t
      23  # include "localcharset.h"
      24  # include "streq.h"
      25  #endif
      26  
      27  #if GL_CHAR32_T_IS_UNICODE
      28  # include "lc-charset-unicode.h"
      29  #endif
      30  
      31  #include "unicase.h"
      32  
      33  #if _GL_WCHAR_T_IS_UCS4 && !GNULIB_defined_mbstate_t
      34  _GL_EXTERN_INLINE
      35  #endif
      36  wint_t
      37  FUNC (wint_t wc)
      38  {
      39    /* The char32_t encoding of a multibyte character is defined by the way
      40       mbrtoc32() is defined.  */
      41  
      42  #if GNULIB_defined_mbstate_t            /* AIX, IRIX */
      43    /* mbrtoc32() is defined on top of mbtowc() for the non-UTF-8 locales
      44       and directly for the UTF-8 locales.  */
      45    if (wc != WEOF)
      46      {
      47        const char *encoding = locale_charset ();
      48        if (STREQ_OPT (encoding, "UTF-8", 'U', 'T', 'F', '-', '8', 0, 0, 0, 0))
      49          return UCS_FUNC (wc);
      50        else
      51          return WCHAR_FUNC (wc);
      52      }
      53    else
      54      return wc;
      55  
      56  #elif HAVE_WORKING_MBRTOC32             /* glibc, Android */
      57    /* mbrtoc32() is essentially defined by the system libc.  */
      58  
      59  # if _GL_WCHAR_T_IS_UCS4
      60    /* The char32_t encoding of a multibyte character is known to be the same as
      61       the wchar_t encoding.  */
      62    return WCHAR_FUNC (wc);
      63  # else
      64    /* The char32_t encoding of a multibyte character is known to be UCS-4,
      65       different from the wchar_t encoding.  */
      66    if (wc != WEOF)
      67      return UCS_FUNC (wc);
      68    else
      69      return wc;
      70  # endif
      71  
      72  #elif _GL_SMALL_WCHAR_T                 /* Cygwin, mingw, MSVC */
      73    /* The wchar_t encoding is UTF-16.
      74       The char32_t encoding is UCS-4.  */
      75  
      76    if (wc == WEOF || wc == (wchar_t) wc)
      77      /* wc is in the range for the tow* functions.  */
      78      return WCHAR_FUNC (wc);
      79    else
      80      return UCS_FUNC (wc);
      81  
      82  #else /* macOS, FreeBSD, NetBSD, OpenBSD, HP-UX, Solaris, Minix, Android */
      83    /* char32_t and wchar_t are equivalent.  */
      84    static_assert (sizeof (char32_t) == sizeof (wchar_t));
      85  
      86  # if GL_CHAR32_T_IS_UNICODE && GL_CHAR32_T_VS_WCHAR_T_NEEDS_CONVERSION
      87    return UCS_FUNC (wc);
      88  # else
      89    return WCHAR_FUNC (wc);
      90  # endif
      91  #endif
      92  }