freebsd-dev/sys/libkern/strtol.c
Pedro F. Giffuni 51369649b0 sys: further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 3-Clause license.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.
2017-11-20 19:43:44 +00:00

129 lines
4.1 KiB
C

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Chris Torek.
*
* 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.
*
* From: @(#)strtol.c 8.1 (Berkeley) 6/4/93
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/ctype.h>
#include <sys/limits.h>
/*
* 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)
{
const char *s = nptr;
unsigned long acc;
unsigned char c;
unsigned long cutoff;
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 (!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 *= base;
acc += c;
}
}
if (any < 0) {
acc = neg ? LONG_MIN : LONG_MAX;
} else if (neg)
acc = -acc;
if (endptr != NULL)
*endptr = __DECONST(char *, any ? s - 1 : nptr);
return (acc);
}