[Minios-devel] [UNIKRAFT PATCH 2/2] lib/nolibc: Add strtol function

[Sharan Santhanam <sharan.santhanam@xxxxxxxxx>]

The patch extends nolibc the strto* family of function with strtol.
The implementation uses the existing strtol function provided within
nolibc.

Signed-off-by: Sharan Santhanam <sharan.santhanam@xxxxxxxxx>
---
 lib/nolibc/exportsyms.uk    |  1 +
 lib/nolibc/include/stdlib.h |  1 +
 lib/nolibc/stdlib.c         | 97 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 99 insertions(+)

diff --git a/lib/nolibc/exportsyms.uk b/lib/nolibc/exportsyms.uk
index b2ebb8d..393c970 100644
--- a/lib/nolibc/exportsyms.uk
+++ b/lib/nolibc/exportsyms.uk
@@ -40,6 +40,7 @@ printf
 fflush
 
 # stdlib
+strtol
 strtoul
 strtoll
 strtoull
diff --git a/lib/nolibc/include/stdlib.h b/lib/nolibc/include/stdlib.h
index 247a3f8..2871815 100644
--- a/lib/nolibc/include/stdlib.h
+++ b/lib/nolibc/include/stdlib.h
@@ -46,6 +46,7 @@ extern "C" {
  * @endptr: A pointer to the end of the parsed string will be placed here
  * @base:   The number base to use
  */
+long strtol(const char *nptr, char **endptr, int base);
 unsigned long strtoul(const char *nptr, char **endptr, int base);
 long long strtoll(const char *nptr, char **endptr, int base);
 unsigned long long strtoull(const char *nptr, char **endptr, int base);
diff --git a/lib/nolibc/stdlib.c b/lib/nolibc/stdlib.c
index 76236af..c83c6de 100644
--- a/lib/nolibc/stdlib.c
+++ b/lib/nolibc/stdlib.c
@@ -51,6 +51,7 @@
  * SUCH DAMAGE.
  */
 
+#include <errno.h>
 #include <stdint.h>
 #include <stdlib.h>
 #include <limits.h>
@@ -129,6 +130,102 @@ exit:
        return acc;
 }
 
+long strtol(const char *nptr, char **endptr, int base)
+{
+       const char *s;
+       unsigned long acc;
+       unsigned char c;
+       unsigned long qbase, cutoff;
+       int neg, any, cutlim;
+
+       s = nptr;
+       if (base < 0 || base == 1 || base > 36) {
+               errno = -EINVAL;
+               any = 0;
+               acc = 0;
+               goto exit;
+       }
+
+       /*
+        * Skip white space and pick up leading +/- sign if any.
+        * If base is 0, allow 0x for hex and 0 for octal, else
+        * assume decimal; if base is already 16, allow 0x.
+        */
+       do {
+               c = *s++;
+       } while (isspace(c));
+       if (c == '-') {
+               neg = 1;
+               c = *s++;
+       } else {
+               neg = 0;
+               if (c == '+')
+                       c = *s++;
+       }
+       if ((base == 0 || base == 16) && c == '0' && (*s == 'x' || *s == 'X')) {
+               c = s[1];
+               s += 2;
+               base = 16;
+       }
+       if (base == 0)
+               base = c == '0' ? 8 : 10;
+
+       /*
+        * Compute the cutoff value between legal numbers and illegal
+        * numbers.  That is the largest legal value, divided by the
+        * base.  An input number that is greater than this value, if
+        * followed by a legal input character, is too big.  One that
+        * is equal to this value may be valid or not; the limit
+        * between valid and invalid numbers is then based on the last
+        * digit.  For instance, if the range for quads is
+        * [-2147483648..2147483647] and the input base
+        * is 10, cutoff will be set to 2147483647 and cutlim to
+        * either 7 (neg==0) or 8 (neg==1), meaning that if we have
+        * accumulated a value > 2147483647, or equal but the
+        * next digit is > 7 (or 8), the number is too big, and we will
+        * return a range error.
+        *
+        * Set any if any `digits' consumed; make it negative to indicate
+        * overflow.
+        */
+       qbase = (unsigned int)base;
+       cutoff = neg
+                    ? (unsigned long)LONG_MAX
+                          - (unsigned long)(LONG_MIN + LONG_MAX)
+                    : LONG_MAX;
+       cutlim = cutoff % qbase;
+       cutoff /= qbase;
+       for (acc = 0, any = 0;; c = *s++) {
+               if (!isascii(c))
+                       break;
+               if (isdigit(c))
+                       c -= '0';
+               else if (isalpha(c))
+                       c -= isupper(c) ? 'A' - 10 : 'a' - 10;
+               else
+                       break;
+               if (c >= base)
+                       break;
+               if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
+                       any = -1;
+               else {
+                       any = 1;
+                       acc *= qbase;
+                       acc += c;
+               }
+       }
+       if (any < 0) {
+               acc = neg ? LONG_MIN : LONG_MAX;
+               errno = ERANGE;
+       } else if (neg)
+               acc = -acc;
+
+exit:
+       if (endptr != 0)
+               *endptr = __DECONST(char *, any ? s - 1 : nptr);
+       return acc;
+}
+
 /*
  * Convert a string to a long long integer.
  *
-- 
2.7.4


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