New module 'mbsnrtowcs'.

1 files changed, 139 insertions, 0 deletions

diff --git a/lib/mbsnrtowcs.c b/lib/mbsnrtowcs.c
new file mode 100644
index 0000000000..57db98d29d
--- /dev/null
+++ b/lib/mbsnrtowcs.c
@@ -0,0 +1,139 @@
+/* Convert string to wide string.
+   Copyright (C) 2008 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2008.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include <wchar.h>
+
+#include <errno.h>
+#include <limits.h>
+#include <stdlib.h>
+
+#include "minmax.h"
+#include "strnlen1.h"
+
+
+extern mbstate_t _gl_mbsrtowcs_state;
+
+size_t
+mbsnrtowcs (wchar_t *dest, const char **srcp, size_t srclen, size_t len, mbstate_t *ps)
+{
+  if (ps == NULL)
+    ps = &_gl_mbsrtowcs_state;
+  {
+    const char *src = *srcp;
+
+    if (dest != NULL)
+      {
+	wchar_t *destptr = dest;
+
+	for (; srclen > 0 && len > 0; destptr++, len--)
+	  {
+	    size_t src_avail;
+	    size_t ret;
+
+	    /* An optimized variant of
+	       src_avail = strnlen1 (src, MIN (srclen, MB_LEN_MAX));  */
+	    if (srclen == 1 || src[0] == '\0')
+	      src_avail = 1;
+	    else if (srclen == 2 || src[1] == '\0')
+	      src_avail = 2;
+	    else if (srclen == 3 || src[2] == '\0')
+	      src_avail = 3;
+	    else if (MB_LEN_MAX <= 4 || srclen == 4 || src[3] == '\0')
+	      src_avail = 4;
+	    else
+	      src_avail = 4 + strnlen1 (src + 4, MIN (srclen, MB_LEN_MAX) - 4);
+
+	    /* Parse the next multibyte character.  */
+	    ret = mbrtowc (destptr, src, src_avail, ps);
+
+	    if (ret == (size_t)(-2))
+	      /* Encountered a multibyte character that extends past a '\0' byte
+		 or that is longer than MB_LEN_MAX bytes.  Cannot happen.  */
+	      abort ();
+
+	    if (ret == (size_t)(-1))
+	      goto bad_input;
+	    if (ret == 0)
+	      {
+		src = NULL;
+		/* Here mbsinit (ps).  */
+		break;
+	      }
+	    src += ret;
+	    srclen -= ret;
+	  }
+
+	*srcp = src;
+	return destptr - dest;
+      }
+    else
+      {
+	/* Ignore dest and len, don't store *srcp at the end, and
+	   don't clobber *ps.  */
+	mbstate_t state = *ps;
+	size_t totalcount = 0;
+
+	for (; srclen > 0; totalcount++)
+	  {
+	    size_t src_avail;
+	    size_t ret;
+
+	    /* An optimized variant of
+	       src_avail = strnlen1 (src, MIN (srclen, MB_LEN_MAX));  */
+	    if (srclen == 1 || src[0] == '\0')
+	      src_avail = 1;
+	    else if (srclen == 2 || src[1] == '\0')
+	      src_avail = 2;
+	    else if (srclen == 3 || src[2] == '\0')
+	      src_avail = 3;
+	    else if (MB_LEN_MAX <= 4 || srclen == 4 || src[3] == '\0')
+	      src_avail = 4;
+	    else
+	      src_avail = 4 + strnlen1 (src + 4, MIN (srclen, MB_LEN_MAX) - 4);
+
+	    /* Parse the next multibyte character.  */
+	    ret = mbrtowc (NULL, src, src_avail, &state);
+
+	    if (ret == (size_t)(-2))
+	      /* Encountered a multibyte character that extends past a '\0' byte
+		 or that is longer than MB_LEN_MAX bytes.  Cannot happen.  */
+	      abort ();
+
+	    if (ret == (size_t)(-1))
+	      goto bad_input2;
+	    if (ret == 0)
+	      {
+		/* Here mbsinit (&state).  */
+		break;
+	      }
+	    src += ret;
+	    srclen -= ret;
+	  }
+
+	return totalcount;
+      }
+
+   bad_input:
+    *srcp = src;
+   bad_input2:
+    errno = EILSEQ;
+    return (size_t)(-1);
+  }
+}