lib/lc-charset-dispatch.c

   1 /* Dispatching based on the current locale's character encoding.
   2    Copyright (C) 2018-2024 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>, 2018.  */
  18
  19 #include <config.h>
  20
  21 /* Specification.  */
  22 #include "lc-charset-dispatch.h"
  23
  24 #if GNULIB_defined_mbstate_t
  25
  26 # include "localcharset.h"
  27 # include "streq.h"
  28
  29 # if GNULIB_WCHAR_SINGLE_LOCALE
  30 /* When we know that the locale does not change, provide a speedup by
  31    caching the value of locale_encoding_classification.  */
  32 #  define locale_encoding_classification_cached locale_encoding_classification
  33 # else
  34 /* By default, don't make assumptions, hence no caching.  */
  35 #  define locale_encoding_classification_uncached locale_encoding_classification
  36 # endif
  37
  38 # if GNULIB_WCHAR_SINGLE_LOCALE
  39 static inline
  40 # endif
  41 enc_t
  42 locale_encoding_classification_uncached (void)
  43 {
  44   const char *encoding = locale_charset ();
  45   if (STREQ_OPT (encoding, "UTF-8", 'U', 'T', 'F', '-', '8', 0, 0, 0, 0))
  46     return enc_utf8;
  47   if (STREQ_OPT (encoding, "EUC-JP", 'E', 'U', 'C', '-', 'J', 'P', 0, 0, 0))
  48     return enc_eucjp;
  49   if (STREQ_OPT (encoding, "EUC-KR", 'E', 'U', 'C', '-', 'K', 'R', 0, 0, 0)
  50       || STREQ_OPT (encoding, "GB2312", 'G', 'B', '2', '3', '1', '2', 0, 0, 0)
  51       || STREQ_OPT (encoding, "BIG5", 'B', 'I', 'G', '5', 0, 0, 0, 0, 0))
  52     return enc_94;
  53   if (STREQ_OPT (encoding, "EUC-TW", 'E', 'U', 'C', '-', 'T', 'W', 0, 0, 0))
  54     return enc_euctw;
  55   if (STREQ_OPT (encoding, "GB18030", 'G', 'B', '1', '8', '0', '3', '0', 0, 0))
  56     return enc_gb18030;
  57   if (STREQ_OPT (encoding, "SJIS", 'S', 'J', 'I', 'S', 0, 0, 0, 0, 0))
  58     return enc_sjis;
  59   return enc_other;
  60 }
  61
  62 # if GNULIB_WCHAR_SINGLE_LOCALE
  63
  64 static int cached_locale_enc = -1;
  65
  66 enc_t
  67 locale_encoding_classification_cached (void)
  68 {
  69   if (cached_locale_enc < 0)
  70     cached_locale_enc = locale_encoding_classification_uncached ();
  71   return cached_locale_enc;
  72 }
  73
  74 # endif
  75
  76 #else
  77
  78 /* This declaration is solely to ensure that after preprocessing
  79    this file is never empty.  */
  80 typedef int dummy;
  81
  82 #endif