minix/common/lib/libc/stdlib/_strtol.h

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/* $NetBSD: _strtol.h,v 1.2 2009/05/20 22:03:29 christos Exp $ */
/*-
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* Original version ID:
* NetBSD: src/lib/libc/locale/_wcstol.h,v 1.2 2003/08/07 16:43:03 agc Exp
*/
/*
* function template for strtol, strtoll and strtoimax.
*
* parameters:
* _FUNCNAME : function name
* __INT : return type
* __INT_MIN : lower limit of the return type
* __INT_MAX : upper limit of the return type
*/
__INT
_FUNCNAME(const char *nptr, char **endptr, int base)
{
const char *s;
__INT acc, cutoff;
unsigned char c;
int i, neg, any, cutlim;
_DIAGASSERT(nptr != NULL);
/* endptr may be NULL */
/* check base value */
if (base && (base < 2 || base > 36)) {
#if !defined(_KERNEL) && !defined(_STANDALONE)
errno = EINVAL;
if (endptr != NULL)
/* LINTED interface specification */
*endptr = __UNCONST(nptr);
return 0;
#else
panic("%s: invalid base %d", __func__, base);
#endif
}
/*
* 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.
*/
s = nptr;
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 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 ? __INT_MIN : __INT_MAX);
cutlim = (int)(cutoff % base);
cutoff /= base;
if (neg) {
if (cutlim > 0) {
cutlim -= base;
cutoff += 1;
}
cutlim = -cutlim;
}
for (acc = 0, any = 0;; c = *s++) {
if (isdigit(c))
i = c - '0';
else if (isalpha(c))
i = c - (isupper(c) ? 'A' - 10 : 'a' - 10);
else
break;
if (i >= base)
break;
if (any < 0)
continue;
if (neg) {
if (acc < cutoff || (acc == cutoff && i > cutlim)) {
acc = __INT_MIN;
#if !defined(_KERNEL) && !defined(_STANDALONE)
any = -1;
errno = ERANGE;
#else
any = 0;
break;
#endif
} else {
any = 1;
acc *= base;
acc -= i;
}
} else {
if (acc > cutoff || (acc == cutoff && i > cutlim)) {
acc = __INT_MAX;
#if !defined(_KERNEL) && !defined(_STANDALONE)
any = -1;
errno = ERANGE;
#else
any = 0;
break;
#endif
} else {
any = 1;
acc *= base;
acc += i;
}
}
}
if (endptr != NULL)
/* LINTED interface specification */
*endptr = __UNCONST(any ? s - 1 : nptr);
return(acc);
}