1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1992, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * Copyright (c) 2011 The FreeBSD Foundation
8 *
9 * Portions of this software were developed by David Chisnall
10 * under sponsorship from the FreeBSD Foundation.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 *    notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 *    notice, this list of conditions and the following disclaimer in the
19 *    documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of the University nor the names of its contributors
21 *    may be used to endorse or promote products derived from this software
22 *    without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37#include <ctype.h>
38#include <errno.h>
39#include <stdlib.h>
40#include <inttypes.h>
41#include "xlocale_private.h"
42
43/*
44 * Convert a string to an intmax_t integer.
45 *
46 * Assumes that the upper and lower case
47 * alphabets and digits are each contiguous.
48 */
49intmax_t
50strtoimax_l(const char * __restrict nptr, char ** __restrict endptr, int base,
51		locale_t locale)
52{
53	const char *s;
54	uintmax_t acc;
55	char c;
56	uintmax_t cutoff;
57	int neg, any, cutlim;
58	FIX_LOCALE(locale);
59
60	/*
61	 * Skip white space and pick up leading +/- sign if any.
62	 * If base is 0, allow 0x for hex and 0 for octal, else
63	 * assume decimal; if base is already 16, allow 0x.
64	 */
65	s = nptr;
66	do {
67		c = *s++;
68	} while (isspace_l((unsigned char)c, locale));
69	if (c == '-') {
70		neg = 1;
71		c = *s++;
72	} else {
73		neg = 0;
74		if (c == '+')
75			c = *s++;
76	}
77	if ((base == 0 || base == 16) &&
78	    c == '0' && (*s == 'x' || *s == 'X') &&
79	    ((s[1] >= '0' && s[1] <= '9') ||
80	    (s[1] >= 'A' && s[1] <= 'F') ||
81	    (s[1] >= 'a' && s[1] <= 'f'))) {
82		c = s[1];
83		s += 2;
84		base = 16;
85	}
86	if ((base == 0 || base == 2) &&
87	    c == '0' && (*s == 'b' || *s == 'B') &&
88	    (s[1] >= '0' && s[1] <= '1')) {
89		c = s[1];
90		s += 2;
91		base = 2;
92	}
93	if (base == 0)
94		base = c == '0' ? 8 : 10;
95	acc = any = 0;
96	if (base < 2 || base > 36)
97		goto noconv;
98
99	/*
100	 * Compute the cutoff value between legal numbers and illegal
101	 * numbers.  That is the largest legal value, divided by the
102	 * base.  An input number that is greater than this value, if
103	 * followed by a legal input character, is too big.  One that
104	 * is equal to this value may be valid or not; the limit
105	 * between valid and invalid numbers is then based on the last
106	 * digit.  For instance, if the range for intmax_t is
107	 * [-9223372036854775808..9223372036854775807] and the input base
108	 * is 10, cutoff will be set to 922337203685477580 and cutlim to
109	 * either 7 (neg==0) or 8 (neg==1), meaning that if we have
110	 * accumulated a value > 922337203685477580, or equal but the
111	 * next digit is > 7 (or 8), the number is too big, and we will
112	 * return a range error.
113	 *
114	 * Set 'any' if any `digits' consumed; make it negative to indicate
115	 * overflow.
116	 */
117	cutoff = neg ? (uintmax_t)-(INTMAX_MIN + INTMAX_MAX) + INTMAX_MAX
118	    : INTMAX_MAX;
119	cutlim = cutoff % base;
120	cutoff /= base;
121	for ( ; ; c = *s++) {
122		if (c >= '0' && c <= '9')
123			c -= '0';
124		else if (c >= 'A' && c <= 'Z')
125			c -= 'A' - 10;
126		else if (c >= 'a' && c <= 'z')
127			c -= 'a' - 10;
128		else
129			break;
130		if (c >= base)
131			break;
132		if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
133			any = -1;
134		else {
135			any = 1;
136			acc *= base;
137			acc += c;
138		}
139	}
140	if (any < 0) {
141		acc = neg ? INTMAX_MIN : INTMAX_MAX;
142		errno = ERANGE;
143	} else if (!any) {
144noconv:
145		errno = EINVAL;
146	} else if (neg)
147		acc = -acc;
148	if (endptr != NULL)
149		*endptr = (char *)(any ? s - 1 : nptr);
150	return (acc);
151}
152intmax_t
153strtoimax(const char * __restrict nptr, char ** __restrict endptr, int base)
154{
155	return strtoimax_l(nptr, endptr, base, __get_locale());
156}
157