1 files changed, 82 insertions, 0 deletions
diff --git a/lib/lc-charset-dispatch.c b/lib/lc-charset-dispatch.c
new file mode 100644
index 00000000..66d78fd3
--- /dev/null
+++ b/lib/lc-charset-dispatch.c
@@ -0,0 +1,82 @@
+/* Dispatching based on the current locale's character encoding.
+   Copyright (C) 2018-2022 Free Software Foundation, Inc.
+
+   This file is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as
+   published by the Free Software Foundation; either version 2.1 of the
+   License, or (at your option) any later version.
+
+   This file 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 Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+/* Written by Bruno Haible <bruno@clisp.org>, 2018.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include "lc-charset-dispatch.h"
+
+#if GNULIB_defined_mbstate_t
+
+# include "localcharset.h"
+# include "streq.h"
+
+# if GNULIB_WCHAR_SINGLE_LOCALE
+/* When we know that the locale does not change, provide a speedup by
+   caching the value of locale_encoding_classification.  */
+#  define locale_encoding_classification_cached locale_encoding_classification
+# else
+/* By default, don't make assumptions, hence no caching.  */
+#  define locale_encoding_classification_uncached locale_encoding_classification
+# endif
+
+# if GNULIB_WCHAR_SINGLE_LOCALE
+static inline
+# endif
+enc_t
+locale_encoding_classification_uncached (void)
+{
+  const char *encoding = locale_charset ();
+  if (STREQ_OPT (encoding, "UTF-8", 'U', 'T', 'F', '-', '8', 0, 0, 0, 0))
+    return enc_utf8;
+  if (STREQ_OPT (encoding, "EUC-JP", 'E', 'U', 'C', '-', 'J', 'P', 0, 0, 0))
+    return enc_eucjp;
+  if (STREQ_OPT (encoding, "EUC-KR", 'E', 'U', 'C', '-', 'K', 'R', 0, 0, 0)
+      || STREQ_OPT (encoding, "GB2312", 'G', 'B', '2', '3', '1', '2', 0, 0, 0)
+      || STREQ_OPT (encoding, "BIG5", 'B', 'I', 'G', '5', 0, 0, 0, 0, 0))
+    return enc_94;
+  if (STREQ_OPT (encoding, "EUC-TW", 'E', 'U', 'C', '-', 'T', 'W', 0, 0, 0))
+    return enc_euctw;
+  if (STREQ_OPT (encoding, "GB18030", 'G', 'B', '1', '8', '0', '3', '0', 0, 0))
+    return enc_gb18030;
+  if (STREQ_OPT (encoding, "SJIS", 'S', 'J', 'I', 'S', 0, 0, 0, 0, 0))
+    return enc_sjis;
+  return enc_other;
+}
+
+# if GNULIB_WCHAR_SINGLE_LOCALE
+
+static int cached_locale_enc = -1;
+
+enc_t
+locale_encoding_classification_cached (void)
+{
+  if (cached_locale_enc < 0)
+    cached_locale_enc = locale_encoding_classification_uncached ();
+  return cached_locale_enc;
+}
+
+# endif
+
+#else
+
+/* This declaration is solely to ensure that after preprocessing
+   this file is never empty.  */
+typedef int dummy;
+
+#endif