* mingwex/mbrtowc.c: New file.

* mingwex/wcrtomb.c: New file.
	* mingwex/btowc.c: New file.
	* mingwex/wctob.c: New file.
	* mingwex/mb_wc_common.h: New file.
	* mingwex/Makefile.in (DISTFILES): Add new files.
	(Q8_OBJS): Add new objects.
	* include/wchar.h: Adjust comment about mbrtowc() and related
	funcions. Add __restrict__ to pointer params in prototypes.
	(wmemset. wmemchr, wmemcpy, wmemmove, wcstoll, wcstoull): Remove
	arg names from protototypes.

winsup/mingw/mingwex/mbrtowc.c

@@ -0,0 +1,164 @@
+#include "mb_wc_common.h"
+#include <wchar.h>
+#include <stdlib.h>
+#include <errno.h>
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+
+#define MBTOWC_FLAGS (MB_PRECOMPOSED | MB_ERR_INVALID_CHARS)
+/* Attribute `nonnull' was valid as of gcc 3.3.  */
+#ifndef ATTRIBUTE_NONNULL
+# if (__GNUC__ > 3 ||( __GNUC__ == 3 &&  __GNUC_MINOR__ >= 3))
+#  define ATTRIBUTE_NONNULL(m...) __attribute__ ((__nonnull__ (m)))
+# else
+#  define ATTRIBUTE_NONNULL(m...)
+# endif /* GNUC >= 3.3 */
+#endif /* ATTRIBUTE_NONNULL */
+
+static int ATTRIBUTE_NONNULL(1, 4)
+__mbrtowc_cp (wchar_t * __restrict__ pwc, const char * __restrict__ s,
+	      size_t n, mbstate_t* __restrict__ ps,
+	      const unsigned int cp, const unsigned int mb_max) 
+{
+  union {
+    mbstate_t val;
+    char mbcs[4];
+  }  shift_state;
+
+
+  /* Do the prelim checks */
+  if (s == NULL)
+    return 0;
+
+  if (n == 0)
+    /* The standard doesn't mention this case explicitly. Tell
+       caller that the conversion from a non-null s is incomplete. */
+    return -2;
+
+  /* Save the current shift state, in case we need it in DBCS case.  */
+  shift_state.val = *ps;
+  *ps = 0;
+
+  if (!*s)
+    {
+      *pwc = 0;
+      return 0;
+    }
+ 
+  if (mb_max > 1)
+    {
+      if (shift_state.mbcs[0] != 0)
+	{
+	  /* Complete the mb char with the trailing byte.  */
+          shift_state.mbcs[1] = *s;  /* the second byte */
+          if (MultiByteToWideChar(cp, MB_ERR_INVALID_CHARS,
+				  shift_state.mbcs, 2, pwc, 1)
+		 == 0)
+	    {
+	      /* An invalid trailing byte */	 
+	      errno = EILSEQ;
+	      return -1;
+	    }
+          return 2;
+        }
+      else if (IsDBCSLeadByteEx (cp, *s))
+        {
+          /* If told to translate one byte, just save the leadbyte
+             in *ps.  */
+	  if (n < 2)
+	    {
+	      ((char*) ps)[0] = *s; 
+	      return -2;
+	    }
+          /* Else translate the first two bytes  */  
+          else if (MultiByteToWideChar (cp, MB_ERR_INVALID_CHARS,
+					s, 2, pwc, 1)
+		    == 0)
+	    {
+	      errno = EILSEQ;
+	      return -1;
+	    }
+          return 2;
+        }
+    }
+
+  /* Fall through to single byte char  */ 
+  if (cp == 0)
+      *pwc = (wchar_t)(unsigned char)*s;
+ 
+  else if (MultiByteToWideChar (cp, MB_ERR_INVALID_CHARS, s, 1, pwc, 1)
+	    == 0)
+    {
+      errno = EILSEQ;
+      return  -1;
+    }
+  return 1;
+}
+
+size_t
+mbrtowc (wchar_t * __restrict__ pwc, const char * __restrict__ s,
+	 size_t n, mbstate_t* __restrict__ ps)
+{
+  static mbstate_t internal_mbstate = 0;
+  wchar_t  byte_bucket = 0;
+  wchar_t* dst = pwc ? pwc : &byte_bucket;
+
+  return (size_t) __mbrtowc_cp (dst, s, n, ps ? ps : &internal_mbstate,
+				get_cp_from_locale(), MB_CUR_MAX);
+}
+
+
+size_t
+mbsrtowcs (wchar_t* __restrict__ dst,  const char ** __restrict__ src,
+	   size_t len, mbstate_t* __restrict__ ps)
+{
+  int ret =0 ;
+  size_t n = 0;
+  static mbstate_t internal_mbstate = 0;
+  mbstate_t* internal_ps = ps ? ps : &internal_mbstate;
+  const unsigned int cp = get_cp_from_locale();;
+  const unsigned int mb_max = MB_CUR_MAX;
+
+  if ( src == NULL || *src == NULL )	/* undefined behavior */
+    return 0;
+
+  if (dst != NULL)
+    {
+      while (n < len
+	     && (ret = __mbrtowc_cp(dst, *src, len - n,
+				    internal_ps, cp, mb_max))
+		  > 0)
+	{
+	  ++dst;
+   	  *src += ret;
+          n += ret;
+        }
+
+      if (n < len && ret == 0)
+        *src = (char *)NULL;
+    }
+  
+  else
+    {
+      wchar_t byte_bucket = 0;
+      while (n < len
+	     && (ret = __mbrtowc_cp (&byte_bucket, *src, mb_max,
+				     internal_ps, cp, mb_max))
+		  > 0)
+	{
+          *src += ret;
+          n += ret;
+        }
+    }
+  return n;
+}
+
+size_t
+mbrlen (const char * __restrict__ s, size_t n,
+	mbstate_t * __restrict__ ps)
+{
+  static mbstate_t s_mbstate = 0;
+  wchar_t byte_bucket = 0;
+  return __mbrtowc_cp (&byte_bucket, s, n, (ps) ? ps : &s_mbstate,
+		       get_cp_from_locale(), MB_CUR_MAX);
+}