[thirdparty/gcc.git] / libiberty / strtol.c

/*-
 * Copyright (c) 1990 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. [rescinded 22 July 1999]
 * 4. 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.
 */

#include <limits.h>
#include <ctype.h>
#include <errno.h>
#if 0
#include <stdlib.h>
#endif
#include "ansidecl.h"

/* FIXME: It'd be nice to configure around these, but the include files are too
   painful.  These macros should at least be more portable than hardwired hex
   constants. */

#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

/*
 * 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(nptr, endptr, base)
	const char *nptr;
	char **endptr;
	register 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;
		errno = ERANGE;
	} else if (neg)
		acc = -acc;
	if (endptr != 0)
		*endptr = (char *) (any ? s - 1 : nptr);
	return (acc);
}
Commit	Line	Data
28e9041c	1	/*-
	2	* Copyright (c) 1990 The Regents of the University of California.
	3	* All rights reserved.
	4	*
	5	* Redistribution and use in source and binary forms, with or without
	6	* modification, are permitted provided that the following conditions
	7	* are met:
	8	* 1. Redistributions of source code must retain the above copyright
	9	* notice, this list of conditions and the following disclaimer.
	10	* 2. Redistributions in binary form must reproduce the above copyright
	11	* notice, this list of conditions and the following disclaimer in the
	12	* documentation and/or other materials provided with the distribution.
7202ac7d	13	* 3. [rescinded 22 July 1999]
28e9041c	14	* 4. Neither the name of the University nor the names of its contributors
	15	* may be used to endorse or promote products derived from this software
	16	* without specific prior written permission.
	17	*
	18	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	19	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	20	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	21	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	22	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	23	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	24	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	25	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	26	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	27	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	28	* SUCH DAMAGE.
	29	*/
	30
	31	#include <limits.h>
	32	#include <ctype.h>
	33	#include <errno.h>
	34	#if 0
	35	#include <stdlib.h>
	36	#endif
	37	#include "ansidecl.h"
	38
	39	/* FIXME: It'd be nice to configure around these, but the include files are too
	40	painful. These macros should at least be more portable than hardwired hex
	41	constants. */
	42
	43	#ifndef ULONG_MAX
	44	#define ULONG_MAX ((unsigned long)(~0L)) /* 0xFFFFFFFF */
	45	#endif
	46
	47	#ifndef LONG_MAX
	48	#define LONG_MAX ((long)(ULONG_MAX >> 1)) /* 0x7FFFFFFF */
	49	#endif
	50
	51	#ifndef LONG_MIN
	52	#define LONG_MIN ((long)(~LONG_MAX)) /* 0x80000000 */
	53	#endif
	54
	55	/*
	56	* Convert a string to a long integer.
	57	*
	58	* Ignores `locale' stuff. Assumes that the upper and lower case
	59	* alphabets and digits are each contiguous.
	60	*/
	61	long
	62	strtol(nptr, endptr, base)
4ed77eec	63	const char *nptr;
28e9041c	64	char **endptr;
	65	register int base;
	66	{
4ed77eec	67	register const char *s = nptr;
28e9041c	68	register unsigned long acc;
	69	register int c;
	70	register unsigned long cutoff;
	71	register int neg = 0, any, cutlim;
	72
	73	/*
	74	* Skip white space and pick up leading +/- sign if any.
	75	* If base is 0, allow 0x for hex and 0 for octal, else
	76	* assume decimal; if base is already 16, allow 0x.
	77	*/
	78	do {
	79	c = *s++;
	80	} while (isspace(c));
	81	if (c == '-') {
	82	neg = 1;
	83	c = *s++;
	84	} else if (c == '+')
	85	c = *s++;
	86	if ((base == 0 \|\| base == 16) &&
	87	c == '0' && (s == 'x' \|\| s == 'X')) {
	88	c = s[1];
	89	s += 2;
	90	base = 16;
	91	}
	92	if (base == 0)
	93	base = c == '0' ? 8 : 10;
	94
	95	/*
	96	* Compute the cutoff value between legal numbers and illegal
	97	* numbers. That is the largest legal value, divided by the
	98	* base. An input number that is greater than this value, if
	99	* followed by a legal input character, is too big. One that
	100	* is equal to this value may be valid or not; the limit
	101	* between valid and invalid numbers is then based on the last
	102	* digit. For instance, if the range for longs is
	103	* [-2147483648..2147483647] and the input base is 10,
	104	* cutoff will be set to 214748364 and cutlim to either
	105	* 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated
	106	* a value > 214748364, or equal but the next digit is > 7 (or 8),
	107	* the number is too big, and we will return a range error.
	108	*
	109	* Set any if any `digits' consumed; make it negative to indicate
	110	* overflow.
	111	*/
	112	cutoff = neg ? -(unsigned long)LONG_MIN : LONG_MAX;
	113	cutlim = cutoff % (unsigned long)base;
	114	cutoff /= (unsigned long)base;
	115	for (acc = 0, any = 0;; c = *s++) {
	116	if (isdigit(c))
	117	c -= '0';
	118	else if (isalpha(c))
	119	c -= isupper(c) ? 'A' - 10 : 'a' - 10;
	120	else
	121	break;
	122	if (c >= base)
	123	break;
	124	if (any < 0 \|\| acc > cutoff \|\| acc == cutoff && c > cutlim)
	125	any = -1;
	126	else {
	127	any = 1;
	128	acc *= base;
	129	acc += c;
	130	}
	131	}
132	if (any < 0) {
133	acc = neg ? LONG_MIN : LONG_MAX;
134	errno = ERANGE;
135	} else if (neg)
136	acc = -acc;
137	if (endptr != 0)
138	endptr = (char ) (any ? s - 1 : nptr);
139	return (acc);
140	}