New module 'mbtowc'.

* lib/stdlib.in.h (mbtowc): New declaration.
* lib/mbtowc.c: New file.
* lib/mbtowc-impl.h: New file, from libutf8 with modifications
* m4/mbtowc.m4: New file.
* m4/stdlib_h.m4 (gl_STDLIB_H_DEFAULTS): Initialize GNULIB_MBTOWC,
REPLACE_MBTOWC.
* modules/stdlib (Makefile.am): Substitute GNULIB_MBTOWC,
REPLACE_MBTOWC.
* modules/mbtowc: New file.
* tests/test-stdlib-c++.cc: Test signature of mbtowc.
* doc/posix-functions/mbtowc.texi: Mention the new module.
* modules/btowc (Depends-on): Add mbtowc.

3 files changed, 85 insertions, 0 deletions

diff --git a/lib/mbtowc-impl.h b/lib/mbtowc-impl.h
new file mode 100644
index 0000000000..1645eb5dcd
--- /dev/null
+++ b/lib/mbtowc-impl.h
@@ -0,0 +1,44 @@
+/* Convert multibyte character to wide character.
+   Copyright (C) 2011 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2011.
+
+   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/>.  */
+
+/* We don't need a static internal state, because the encoding is not state
+   dependent, and when mbrtowc returns (size_t)(-2). we throw the result
+   away. */
+
+int
+mbtowc (wchar_t *pwc, const char *s, size_t n)
+{
+  if (s == NULL)
+    return 0;
+  else
+    {
+      mbstate_t state;
+      wchar_t wc;
+      size_t result;
+
+      memset (&state, 0, sizeof (mbstate_t));
+      result = mbrtowc (&wc, s, n, &state);
+      if (result == (size_t)-1 || result == (size_t)-2)
+        {
+          errno = EILSEQ;
+          return -1;
+        }
+      if (pwc != NULL)
+        *pwc = wc;
+      return (wc == 0 ? 0 : result);
+    }
+}
diff --git a/lib/mbtowc.c b/lib/mbtowc.c
new file mode 100644
index 0000000000..b3848a1249
--- /dev/null
+++ b/lib/mbtowc.c
@@ -0,0 +1,26 @@
+/* Convert multibyte character to wide character.
+   Copyright (C) 2011 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2011.
+
+   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>
+
+#include <stdlib.h>
+
+#include <errno.h>
+#include <string.h>
+#include <wchar.h>
+
+#include "mbtowc-impl.h"
diff --git a/lib/stdlib.in.h b/lib/stdlib.in.h
index 62d18c6281..91eb4d68c1 100644
--- a/lib/stdlib.in.h
+++ b/lib/stdlib.in.h
@@ -274,6 +274,21 @@ _GL_WARN_ON_USE (malloc, "malloc is not POSIX compliant everywhere - "
                  "use gnulib module malloc-posix for portability");
 #endif
 
+/* Convert a multibyte character to a wide character.  */
+#if @GNULIB_MBTOWC@
+# if @REPLACE_MBTOWC@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef mbtowc
+#   define mbtowc rpl_mbtowc
+#  endif
+_GL_FUNCDECL_RPL (mbtowc, int, (wchar_t *pwc, const char *s, size_t n));
+_GL_CXXALIAS_RPL (mbtowc, int, (wchar_t *pwc, const char *s, size_t n));
+# else
+_GL_CXXALIAS_SYS (mbtowc, int, (wchar_t *pwc, const char *s, size_t n));
+# endif
+_GL_CXXALIASWARN (mbtowc);
+#endif
+
 #if @GNULIB_MKDTEMP@
 /* Create a unique temporary directory from TEMPLATE.
    The last six characters of TEMPLATE must be "XXXXXX";