Implement btowc() in terms of mbrtowc() instead of sgetrune(), and

wctob() in terms of wcrtomb() instead of sputrune(). There should be
no functional differences, but there may be a small performance hit
because we make an extra function call.

The aim here is to have as few functions as possible calling
s{get,put}rune() to make it easier to remove them in the future.

2 files changed, 27 insertions, 10 deletions

diff --git a/lib/libc/locale/btowc.c b/lib/libc/locale/btowc.c
index 585abf8..b0b24f2 100644
--- a/lib/libc/locale/btowc.c
+++ b/lib/libc/locale/btowc.c
@@ -1,5 +1,5 @@
 /*-
- * Copyright (c) 2002 Tim J. Robbins.
+ * Copyright (c) 2002, 2003 Tim J. Robbins.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -27,19 +27,29 @@
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
-#include <rune.h>
+#include <stdio.h>
+#include <string.h>
 #include <wchar.h>
 
 wint_t
 btowc(int c)
 {
-	rune_t r;
 	char cc;
+	wchar_t wc;
 
 	if (c == EOF)
 		return (WEOF);
 	cc = (char)c;
-	if ((r = sgetrune(&cc, 1, NULL)) == _INVALID_RUNE)
+	/*
+	 * We expect mbrtowc() to return 0 or 1, hence the check for n > 1
+	 * which detects error return values as well as "impossible" byte
+	 * counts.
+	 *
+	 * We pass NULL as the state pointer to mbrtowc() because we don't
+	 * support state-dependent encodings and don't want to waste time
+	 * creating a zeroed mbstate_t that will not be used.
+	 */
+	if (mbrtowc(&wc, &cc, 1, NULL) > 1)
 		return (WEOF);
-	return (r);
+	return (wc);
 }
diff --git a/lib/libc/locale/wctob.c b/lib/libc/locale/wctob.c
index 070ae94..da7afcf 100644
--- a/lib/libc/locale/wctob.c
+++ b/lib/libc/locale/wctob.c
@@ -1,5 +1,5 @@
 /*-
- * Copyright (c) 2002 Tim J. Robbins.
+ * Copyright (c) 2002, 2003 Tim J. Robbins.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -27,15 +27,22 @@
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
-#include <rune.h>
+#include <limits.h>
+#include <stdio.h>
+#include <string.h>
 #include <wchar.h>
 
 int
 wctob(wint_t c)
 {
-	char cc;
+	char buf[MB_LEN_MAX];
 
-	if (c == WEOF || sputrune(c, &cc, 1, NULL) != 1)
+	/*
+	 * We pass NULL as the state pointer to wcrtomb() because we don't
+	 * support state-dependent encodings and don't want to waste time
+	 * creating a zeroed mbstate_t that will not be used.
+	 */
+	if (c == WEOF || wcrtomb(buf, c, NULL) != 1)
 		return (EOF);
-	return ((unsigned char)cc);
+	return ((unsigned char)*buf);
 }