llvm-6502/runtime/GCCLibraries/libc/atox.c

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//===-- atox.c - Ascii string parsers for LLVM libc Library -------*- C -*-===//
//
// A lot of this code is ripped gratuitously from glibc and libiberty.
//
//===----------------------------------------------------------------------===//
#define isspace(x) ((x) == ' ' || (x) == '\t' || (x) == '\n')
#define isdigit(x) ((x) >= '0' && (x) <= '9')
#define isupper(x) ((x) >= 'A' && (x) <= 'Z')
#define islower(x) ((x) >= 'a' && (x) <= 'z')
#define isalpha(x) (isupper(x) || islower(x))
#ifndef ULONG_MAX
#define ULONG_MAX ((unsigned long)(~0L)) /* 0xFFFFFFFF */
#endif
#ifndef LONG_MAX
#define LONG_MAX ((long)(ULONG_MAX >> 1)) /* 0x7FFFFFFF */
#endif
#ifndef LONG_MIN
#define LONG_MIN ((long)(~LONG_MAX)) /* 0x80000000 */
#endif
#if 0
/*
* Convert a string to a long integer.
*
* Ignores `locale' stuff. Assumes that the upper and lower case
* alphabets and digits are each contiguous.
*/
long strtol(const char *nptr, char **endptr, int base) {
register const char *s = nptr;
register unsigned long acc;
register int c;
register unsigned long cutoff;
register int neg = 0, any, cutlim;
/*
* 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 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 longs is
* [-2147483648..2147483647] and the input base is 10,
* cutoff will be set to 214748364 and cutlim to either
* 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated
* a value > 214748364, 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.
*/
cutoff = neg ? -(unsigned long)LONG_MIN : LONG_MAX;
cutlim = cutoff % (unsigned long)base;
cutoff /= (unsigned long)base;
for (acc = 0, any = 0;; c = *s++) {
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 *= base;
acc += c;
}
}
if (any < 0) {
acc = neg ? LONG_MIN : LONG_MAX;
} else if (neg)
acc = -acc;
if (endptr != 0)
*endptr = (char *) (any ? s - 1 : nptr);
return (acc);
}
/* Convert a string to an int. */
int atoi(const char *nptr) {
return (int)strtol(nptr, 0, 10);
}
/* Convert a string to a long int. */
long int atol(const char *nptr) {
return strtol(nptr, 0, 10);
}
#endif