1 files changed, 68 insertions, 0 deletions
diff --git a/lib/btoc32.c b/lib/btoc32.c
new file mode 100644
index 0000000..4f22305
--- /dev/null
+++ b/lib/btoc32.c
@@ -0,0 +1,68 @@
+/* Convert unibyte character to 32-bit wide character.
+   Copyright (C) 2020-2024 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>, 2020.  */
+
+#include <config.h>
+
+#define IN_BTOC32
+/* Specification.  */
+#include <uchar.h>
+
+#include <stdio.h>
+#include <string.h>
+#include <wchar.h>
+
+#if GL_CHAR32_T_IS_UNICODE
+# include "lc-charset-unicode.h"
+#endif
+
+#if _GL_WCHAR_T_IS_UCS4
+_GL_EXTERN_INLINE
+#endif
+wint_t
+btoc32 (int c)
+{
+#if HAVE_WORKING_MBRTOC32 && !_GL_WCHAR_T_IS_UCS4
+  /* The char32_t encoding of a multibyte character may be different than its
+     wchar_t encoding.  */
+  if (c != EOF)
+    {
+      mbstate_t state;
+      char s[1];
+      char32_t wc;
+
+      mbszero (&state);
+      s[0] = (unsigned char) c;
+      if (mbrtoc32 (&wc, s, 1, &state) <= 1)
+        return wc;
+    }
+  return WEOF;
+#else
+  /* In all known locale encodings, unibyte characters correspond only to
+     characters in the BMP.  */
+  wint_t wc = btowc (c);
+# if GL_CHAR32_T_IS_UNICODE && GL_CHAR32_T_VS_WCHAR_T_NEEDS_CONVERSION
+  if (wc != WEOF && wc != 0)
+    {
+      wc = locale_encoding_to_unicode (wc);
+      if (wc == 0)
+        return WEOF;
+    }
+# endif
+  return wc;
+#endif
+}