newlib: wide char support

git-svn-id: svn://kolibrios.org@6607 a494cfbc-eb01-0410-851d-a64ba20cac60

contrib/sdk/sources/newlib/libc/stdlib/wcstombs.c

@@ -0,0 +1,83 @@
+/*
+FUNCTION
+<<wcstombs>>---minimal wide char string to multibyte string converter
+
+INDEX
+	wcstombs
+
+ANSI_SYNOPSIS
+	#include <stdlib.h>
+	size_t wcstombs(char *restrict <[s]>, const wchar_t *restrict <[pwc]>, size_t <[n]>);
+
+TRAD_SYNOPSIS
+	#include <stdlib.h>
+	size_t wcstombs(<[s]>, <[pwc]>, <[n]>)
+	char *<[s]>;
+	const wchar_t *<[pwc]>;
+	size_t <[n]>;
+
+DESCRIPTION
+When _MB_CAPABLE is not defined, this is a minimal ANSI-conforming 
+implementation of <<wcstombs>>.  In this case,
+all wide-characters are expected to represent single bytes and so
+are converted simply by casting to char.
+
+When _MB_CAPABLE is defined, this routine calls <<_wcstombs_r>> to perform
+the conversion, passing a state variable to allow state dependent
+decoding.  The result is based on the locale setting which may
+be restricted to a defined set of locales.
+
+RETURNS
+This implementation of <<wcstombs>> returns <<0>> if
+<[s]> is <<NULL>> or is the empty string; 
+it returns <<-1>> if _MB_CAPABLE and one of the
+wide-char characters does not represent a valid multi-byte character;
+otherwise it returns the minimum of: <<n>> or the
+number of bytes that are transferred to <<s>>, not including the
+nul terminator.
+
+If the return value is -1, the state of the <<pwc>> string is
+indeterminate.  If the input has a length of 0, the output
+string will be modified to contain a wchar_t nul terminator if
+<<n>> > 0.
+
+PORTABILITY
+<<wcstombs>> is required in the ANSI C standard.  However, the precise
+effects vary with the locale.
+
+<<wcstombs>> requires no supporting OS subroutines.
+*/
+
+#ifndef _REENT_ONLY
+
+#include <newlib.h>
+#include <stdlib.h>
+#include <wchar.h>
+
+size_t
+_DEFUN (wcstombs, (s, pwcs, n),
+        char          *__restrict s    _AND
+        const wchar_t *__restrict pwcs _AND
+        size_t         n)
+{
+#ifdef _MB_CAPABLE
+  mbstate_t state;
+  state.__count = 0;
+  
+  return _wcstombs_r (_REENT, s, pwcs, n, &state);
+#else /* not _MB_CAPABLE */
+  int count = 0;
+  
+  if (n != 0) {
+    do {
+      if ((*s++ = (char) *pwcs++) == 0)
+	break;
+      count++;
+    } while (--n != 0);
+  }
+  
+  return count;
+#endif /* not _MB_CAPABLE */
+}
+
+#endif /* !_REENT_ONLY */