1 files changed, 70 insertions, 0 deletions
diff --git a/tests/c32tob.c b/tests/c32tob.c
new file mode 100644
index 00000000..901c9249
--- /dev/null
+++ b/tests/c32tob.c
@@ -0,0 +1,70 @@
+/* Convert 32-bit wide character to unibyte 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 3 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_C32TOB
+/* 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
+int
+c32tob (wint_t wc)
+{
+#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 (wc != WEOF)
+    {
+      mbstate_t state;
+      char buf[8];
+
+      mbszero (&state);
+      if (c32rtomb (buf, wc, &state) == 1)
+        return (unsigned char) buf[0];
+    }
+  return EOF;
+#elif _GL_SMALL_WCHAR_T
+  /* In all known encodings, unibyte characters correspond only to
+     characters in the BMP.  */
+  if (wc != WEOF && (wchar_t) wc == wc)
+    return wctob ((wchar_t) wc);
+  else
+    return EOF;
+#else
+# if GL_CHAR32_T_IS_UNICODE && GL_CHAR32_T_VS_WCHAR_T_NEEDS_CONVERSION
+  if (wc != 0)
+    {
+      wc = unicode_to_locale_encoding (wc);
+      if (wc == 0)
+        return EOF;
+    }
+# endif
+  return wctob (wc);
+#endif
+}