1 files changed, 59 insertions, 0 deletions
diff --git a/lib/libc/string/strchrnul.c b/lib/libc/string/strchrnul.c
new file mode 100644
index 000000000000..3a42c0e7c4c5
--- /dev/null
+++ b/lib/libc/string/strchrnul.c
@@ -0,0 +1,59 @@
+/*-
+ * SPDX-License-Identifier: MIT
+ *
+ * Copyright (c) 2005-2014 Rich Felker, et al.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#include <limits.h>
+#include <stdint.h>
+#include <string.h>
+
+#define ALIGN (sizeof(size_t))
+#define ONES ((size_t)-1 / UCHAR_MAX)
+#define HIGHS (ONES * (UCHAR_MAX / 2 + 1))
+#define HASZERO(x) (((x)-ONES) & ~(x)&HIGHS)
+
+char *__strchrnul(const char *, int);
+
+char *
+__strchrnul(const char *s, int c)
+{
+	c = (unsigned char)c;
+	if (!c)
+		return (char *)s + strlen(s);
+
+#ifdef __GNUC__
+	typedef size_t __attribute__((__may_alias__)) word;
+	const word *w;
+	for (; (uintptr_t)s % ALIGN; s++)
+		if (!*s || *(unsigned char *)s == c)
+			return (char *)s;
+	size_t k = ONES * c;
+	for (w = (void *)s; !HASZERO(*w) && !HASZERO(*w ^ k); w++)
+		;
+	s = (void *)w;
+#endif
+	for (; *s && *(unsigned char *)s != c; s++)
+		;
+	return (char *)s;
+}
+
+__weak_reference(__strchrnul, strchrnul);