[Minios-devel] [UNIKRAFT PATCH v2 1/1] lib/nolibc: Add strtok to string.h

[Florian Schmidt <florian.schmidt@xxxxxxxxx>]

From: Razvan Cojocaru <razvan.cojocaru93@xxxxxxxxx>

Added strtok and dependent functions to string.h
These are required for the Xen network netfront driver.

Functions are copied with only slight style modifications
Taken from musl v1.1.19
Commit <55df09bfccbfe21fc9dd7d8f94550c0ff25ace04>

Signed-off-by: Razvan Cojocaru <razvan.cojocaru93@xxxxxxxxx>
Signed-off-by: Florian Schmidt <florian.schmidt@xxxxxxxxx>
---
 lib/nolibc/include/string.h |   7 ++-
 lib/nolibc/string.c         | 100 +++++++++++++++++++++++++++++++-----
 2 files changed, 93 insertions(+), 14 deletions(-)

diff --git a/lib/nolibc/include/string.h b/lib/nolibc/include/string.h
index 677f528..7a09e41 100644
--- a/lib/nolibc/include/string.h
+++ b/lib/nolibc/include/string.h
@@ -54,10 +54,15 @@ char *strncpy(char *dst, const char *src, size_t len);
 char *strcpy(char *dst, const char *src);
 size_t strnlen(const char *str, size_t maxlen);
 size_t strlen(const char *str);
-const char *strchr(const char *str, int c);
+char *strchrnul(const char *s, int c);
+char *strchr(const char *str, int c);
 int strncmp(const char *str1, const char *str2, size_t len);
 int strcmp(const char *str1, const char *str2);
 
+size_t strcspn(const char *s, const char *c);
+size_t strspn(const char *s, const char *c);
+char *strtok(char *restrict s, const char *restrict sep);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/lib/nolibc/string.c b/lib/nolibc/string.c
index bf89106..0ff587f 100644
--- a/lib/nolibc/string.c
+++ b/lib/nolibc/string.c
@@ -130,19 +130,6 @@ char *strcpy(char *dst, const char *src)
        return strncpy(dst, src, SIZE_MAX);
 }
 
-const char *strchr(const char *str, int c)
-{
-       const char *pos = str;
-
-       for (; *pos != '\0'; ++pos)
-               if (*pos == (char) c)
-                       return pos;
-       if (c == 0)
-               return pos;
-
-       return NULL;
-}
-
 int strncmp(const char *str1, const char *str2, size_t len)
 {
        const char *c1 = (const char *)str1;
@@ -166,3 +153,90 @@ int strcmp(const char *str1, const char *str2)
 
        return __res;
 }
+
+/* Taken from musl libc */
+#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)
+#define BITOP(a, b, op) \
+               ((a)[(size_t)(b) / (8*sizeof *(a))] op \
+               (size_t)1 << ((size_t)(b) % (8 * sizeof *(a))))
+
+char *strchrnul(const char *s, int c)
+{
+       size_t *w, k;
+
+       c = (unsigned char)c;
+       if (!c)
+               return (char *)s + strlen(s);
+
+       for (; (uintptr_t)s % ALIGN; s++)
+               if (!*s || *(unsigned char *)s == c)
+                       return (char *)s;
+       k = ONES * c;
+       for (w = (void *)s; !HASZERO(*w) && !HASZERO(*w ^ k); w++)
+               ;
+       for (s = (void *)w; *s && *(unsigned char *)s != c; s++)
+               ;
+       return (char *)s;
+}
+
+char *strchr(const char *str, int c)
+{
+       char *r = strchrnul(str, c);
+       return *(unsigned char *)r == (unsigned char)c ? r : 0;
+}
+
+size_t strcspn(const char *s, const char *c)
+{
+       const char *a = s;
+       size_t byteset[32 / sizeof(size_t)];
+
+       if (!c[0] || !c[1])
+               return strchrnul(s, *c)-a;
+
+       memset(byteset, 0, sizeof(byteset));
+       for (; *c && BITOP(byteset, *(unsigned char *)c, |=); c++)
+               ;
+       for (; *s && !BITOP(byteset, *(unsigned char *)s, &); s++)
+               ;
+       return s-a;
+}
+
+size_t strspn(const char *s, const char *c)
+{
+       const char *a = s;
+       size_t byteset[32 / sizeof(size_t)] = { 0 };
+
+       if (!c[0])
+               return 0;
+       if (!c[1]) {
+               for (; *s == *c; s++)
+                       ;
+               return s-a;
+       }
+
+       for (; *c && BITOP(byteset, *(unsigned char *)c, |=); c++)
+               ;
+       for (; *s && BITOP(byteset, *(unsigned char *)s, &); s++)
+               ;
+       return s-a;
+}
+
+char *strtok(char *restrict s, const char *restrict sep)
+{
+       static char *p;
+
+       if (!s && !(s = p))
+               return NULL;
+       s += strspn(s, sep);
+       if (!*s)
+               return p = 0;
+       p = s + strcspn(s, sep);
+       if (*p)
+               *p++ = 0;
+       else
+               p = 0;
+       return s;
+}
-- 
2.18.0


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