libs/libc/wchar: add wcslcat implementation

Signed-off-by: guoshichao <guoshichao@xiaomi.com>

libs/libc/wchar/Make.defs

@@ -27,7 +27,7 @@ CSRCS += lib_wcscoll.c lib_wcstol.c lib_wcstoll.c lib_wcstoul.c
 CSRCS += lib_wcstoull.c lib_wcstold.c lib_wcstof.c lib_wcstod.c
 CSRCS += lib_swprintf.c lib_mbsnrtowcs.c lib_wcsnrtombs.c lib_mbsinit.c
 CSRCS += lib_mbrlen.c lib_mbsrtowcs.c lib_wcsrtombs.c lib_wcscpy.c
-CSRCS += lib_wcscat.c
+CSRCS += lib_wcscat.c lib_wcslcat.c
 
 # Add the wchar directory to the build
 

libs/libc/wchar/lib_wcslcat.c

@@ -0,0 +1,103 @@
+/****************************************************************************
+ * libs/libc/wchar/lib_wcslcat.c
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
+ * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * from OpenBSD: strlcat.c,v 1.3 2000/11/24 11:10:02 itojun Exp
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <wchar.h>
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name:  wcslcat
+ *
+ * Description:
+ *     Appends src to string dst of size siz (unlike wcsncat, siz is the
+ *     full size of dst, not space left).  At most siz-1 characters
+ *     will be copied.  Always NUL terminates (unless siz == 0).
+ *     Returns wcslen(initial dst) + wcslen(src); if retval >= siz,
+ *     truncation occurred.
+ *
+ * Input Parameters:
+ *   dst - the dest wchar string that contains the concatenated string
+ *   src - the source wchar string that we need to concatenate
+ *   siz - the max length that can be written to the end of the dst string
+ *
+ * Returned Value:
+ *   The total length of the wchar string that concatenated
+ *
+ ****************************************************************************/
+
+size_t wcslcat(FAR wchar_t *dst, FAR const wchar_t *src, size_t siz)
+{
+  FAR wchar_t *d = dst;
+  FAR const wchar_t *s = src;
+  size_t n = siz;
+  size_t dlen;
+
+  /* Find the end of dst and adjust bytes left but don't go past end */
+
+  while (n-- != 0 && *d != '\0')
+    {
+      d++;
+    }
+
+  dlen = d - dst;
+  n = siz - dlen;
+
+  if (n == 0)
+    {
+      return(dlen + wcslen(s));
+    }
+
+  while (*s != '\0')
+    {
+      if (n != 1)
+        {
+          *d++ = *s;
+          n--;
+        }
+
+      s++;
+    }
+
+  *d = '\0';
+
+  /* count does not include NUL */
+
+  return(dlen + (s - src));
+}