From fcd7f38f46d0aa7d0ec3352f4522c1beb3ed2e7c Mon Sep 17 00:00:00 2001
From: "Tim J. Robbins" <tjr@FreeBSD.org>
Date: Thu, 24 Oct 2002 02:53:45 +0000
Subject: [PATCH] Replace wcsstr() with an implementation based on strstr(),
 which is far more efficient. The problem with the previous implementation was
 that it calculated the length of the first argument ("big") with wcslen()
 when it was not necessary.

---
 lib/libc/string/wcsstr.c | 70 ++++++++++++++++++----------------------
 1 file changed, 32 insertions(+), 38 deletions(-)

diff --git a/lib/libc/string/wcsstr.c b/lib/libc/string/wcsstr.c
index 99e8ac00c0c9..e391e9f57d7b 100644
--- a/lib/libc/string/wcsstr.c
+++ b/lib/libc/string/wcsstr.c
@@ -1,6 +1,9 @@
 /*-
- * Copyright (c)1999 Citrus Project,
- * All rights reserved.
+ * Copyright (c) 1990, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Chris Torek.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -10,11 +13,18 @@
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
  *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
@@ -22,52 +32,36 @@
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
- *
- *	citrus Id: wcsstr.c,v 1.2 2000/12/21 05:07:25 itojun Exp
  */
 
-#include <sys/cdefs.h>
 #if 0
 #if defined(LIBC_SCCS) && !defined(lint)
-__RCSID("$NetBSD: wcsstr.c,v 1.1 2000/12/23 23:14:37 itojun Exp $");
+static char sccsid[] = "@(#)strstr.c	8.1 (Berkeley) 6/4/93";
 #endif /* LIBC_SCCS and not lint */
 #endif
+#include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
 #include <wchar.h>
 
+/*
+ * Find the first occurrence of find in s.
+ */
 wchar_t *
-wcsstr(big, little)
-	const wchar_t * __restrict big;
-	const wchar_t * __restrict little;
+wcsstr(const wchar_t * __restrict s, const wchar_t * __restrict find)
 {
-	const wchar_t *p;
-	const wchar_t *q;
-	const wchar_t *r;
+	wchar_t c, sc;
+	size_t len;
 
-	if (!*little) {
-		/* LINTED interface specification */
-		return (wchar_t *)big;
+	if ((c = *find++) != 0) {
+		len = wcslen(find);
+		do {
+			do {
+				if ((sc = *s++) == L'\0')
+					return (NULL);
+			} while (sc != c);
+		} while (wcsncmp(s, find, len) != 0);
+		s--;
 	}
-	if (wcslen(big) < wcslen(little))
-		return NULL;
-
-	p = big;
-	q = little;
-	while (*p) {
-		q = little;
-		r = p;
-		while (*q) {
-			if (*r != *q)
-				break;
-			q++;
-			r++;
-		}
-		if (!*q) {
-			/* LINTED interface specification */
-			return (wchar_t *)p;
-		}
-		p++;
-	}
-	return NULL;
+	return ((wchar_t *)s);
 }