net-snmp/snmplib/strtoull.c

163 lines
3.6 KiB
C

/*
* An implementation of strtoull() for compilers that do not have this
* function, e.g. MSVC.
* See also http://www.opengroup.org/onlinepubs/000095399/functions/strtoul.html
* for more information about strtoull().
*/
/*
* For MSVC, disable the warning "unary minus operator applied to unsigned
* type, result still unsigned"
*/
#ifdef _MSC_VER
#pragma warning (disable: 4146)
#endif
#define __STDC_CONSTANT_MACROS /* Enable UINT64_C in <stdint.h> */
#define __STDC_FORMAT_MACROS /* Enable PRIu64 in <inttypes.h> */
#include <net-snmp/net-snmp-config.h>
#ifndef HAVE_STRTOULL
#include <errno.h>
#include <ctype.h>
#include <limits.h>
#ifdef HAVE_INTTYPES_H
#include <inttypes.h>
#endif
#include <net-snmp/types.h>
#include <net-snmp/library/system.h>
/*
* UINT64_C: C99 macro for the suffix for uint64_t constants.
*/
#ifndef UINT64_C
#ifdef _MSC_VER
#define UINT64_C(c) c##ui64
#else
#define UINT64_C(c) c##ULL
#endif
#endif
/*
* According to the C99 standard, the constant ULLONG_MAX must be defined in
* <limits.h>. Define it here for pre-C99 compilers.
*/
#ifndef ULLONG_MAX
#define ULLONG_MAX UINT64_C(0xffffffffffffffff)
#endif
uint64_t
strtoull(const char *nptr, char **endptr, int base)
{
uint64_t result = 0;
const char *p;
const char *first_nonspace;
const char *digits_start;
int sign = 1;
int out_of_range = 0;
if (base != 0 && (base < 2 || base > 36))
goto invalid_input;
p = nptr;
/*
* Process the initial, possibly empty, sequence of white-space characters.
*/
while (isspace((unsigned char) (*p)))
p++;
first_nonspace = p;
/*
* Determine sign.
*/
if (*p == '+')
p++;
else if (*p == '-') {
p++;
sign = -1;
}
if (base == 0) {
/*
* Determine base.
*/
if (*p == '0') {
if ((p[1] == 'x' || p[1] == 'X')) {
if (isxdigit((unsigned char)(p[2]))) {
base = 16;
p += 2;
} else {
/*
* Special case: treat the string "0x" without any further
* hex digits as a decimal number.
*/
base = 10;
}
} else {
base = 8;
p++;
}
} else {
base = 10;
}
} else if (base == 16) {
/*
* For base 16, skip the optional "0x" / "0X" prefix.
*/
if (*p == '0' && (p[1] == 'x' || p[1] == 'X')
&& isxdigit((unsigned char)(p[2]))) {
p += 2;
}
}
digits_start = p;
for (; *p; p++) {
int digit;
digit = ('0' <= *p && *p <= '9') ? *p - '0'
: ('a' <= *p && *p <= 'z') ? (*p - 'a' + 10)
: ('A' <= *p && *p <= 'Z') ? (*p - 'A' + 10) : 36;
if (digit < base) {
if (! out_of_range) {
if (result > ULLONG_MAX / base
|| result * base > ULLONG_MAX - digit) {
out_of_range = 1;
}
result = result * base + digit;
}
} else
break;
}
if (p > first_nonspace && p == digits_start)
goto invalid_input;
if (p == first_nonspace)
p = nptr;
if (endptr)
*endptr = (char *) p;
if (out_of_range) {
errno = ERANGE;
return ULLONG_MAX;
}
return sign > 0 ? result : -result;
invalid_input:
errno = EINVAL;
if (endptr)
*endptr = (char *) nptr;
return 0;
}
#endif /* HAVE_STRTOULL */