[kvm-unit-tests PATCH v2 1/3] lib/string: Add stroull and strtoll

ahmeddan
2021-09-27T15:30:47Z

From: Daniele Ahmed <ahmeddan@amazon.com>

Add the two functions strtoull and strtoll.
This is in preparation for an update
in x86/msr.c to write 64b values
that are given as inputs as strings by
a user.

Signed-off-by: Daniele Ahmed <ahmeddan@amazon.com>
---
lib/stdlib.h | 2 ++
lib/string.c | 74 ++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 76 insertions(+)

diff --git a/lib/stdlib.h b/lib/stdlib.h
index 33c00e8..48e10f0 100644
--- a/lib/stdlib.h
+++ b/lib/stdlib.h
@@ -9,5 +9,7 @@

long int strtol(const char *nptr, char **endptr, int base);
unsigned long int strtoul(const char *nptr, char **endptr, int base);
+long long int strtoll(const char *nptr, char **endptr, int base);
+unsigned long long strtoull(const char *nptr, char **endptr, int base);

#endif /* _STDLIB_H_ */
diff --git a/lib/string.c b/lib/string.c
index ffc7c7e..dacd927 100644
--- a/lib/string.c
+++ b/lib/string.c
@@ -242,6 +242,80 @@ unsigned long int strtoul(const char *nptr, char **endptr, int base)
return __strtol(nptr, endptr, base, false);
}

+static unsigned long long __strtoll(const char *nptr, char **endptr,
+ int base, bool is_signed) {
+ unsigned long long acc = 0;
+ const char *s = nptr;
+ int neg, c;
+
+ assert(base == 0 || (base >= 2 && base <= 36));
+
+ while (isspace(*s))
+ s++;
+
+ if (*s == '-') {
+ neg = 1;
+ s++;
+ } else {
+ neg = 0;
+ if (*s == '+')
+ s++;
+ }
+
+ if (base == 0 || base == 16) {
+ if (*s == '0') {
+ s++;
+ if (*s == 'x' || *s == 'X') {
+ s++;
+ base = 16;
+ } else if (base == 0)
+ base = 8;
+ } else if (base == 0)
+ base = 10;
+ }
+
+ while (*s) {
+ if (*s >= '0' && *s < '0' + base && *s <= '9')
+ c = *s - '0';
+ else if (*s >= 'a' && *s < 'a' + base - 10)
+ c = *s - 'a' + 10;
+ else if (*s >= 'A' && *s < 'A' + base - 10)
+ c = *s - 'A' + 10;
+ else
+ break;
+
+ if (is_signed) {
+ long long sacc = (long long)acc;
+ assert(!check_mul_overflow(sacc, base));
+ assert(!check_add_overflow(sacc * base, c));
+ } else {
+ assert(!check_mul_overflow(acc, base));
+ assert(!check_add_overflow(acc * base, c));
+ }
+
+ acc = acc * base + c;
+ s++;
+ }
+
+ if (neg)
+ acc = -acc;
+
+ if (endptr)
+ *endptr = (char *)s;
+
+ return acc;
+}
+
+long long int strtoll(const char *nptr, char **endptr, int base)
+{
+ return __strtoll(nptr, endptr, base, true);
+}
+
+unsigned long long int strtoull(const char *nptr, char **endptr, int base)
+{
+ return __strtoll(nptr, endptr, base, false);
+}
+
long atol(const char *ptr)
{
return strtol(ptr, NULL, 10);
--
2.32.0