1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1990, 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 <limits.h>
38 #include <ctype.h>
39 #include <errno.h>
40 #include <stdlib.h>
41 #include "xlocale_private.h"
42
43 /*
44 * Convert a string to a long integer.
45 *
46 * Assumes that the upper and lower case
47 * alphabets and digits are each contiguous.
48 */
49 long
strtol_l(const char * __restrict nptr,char ** __restrict endptr,int base,locale_t locale)50 strtol_l(const char * __restrict nptr, char ** __restrict endptr, int base,
51 locale_t locale)
52 {
53 const char *s;
54 unsigned long acc;
55 char c;
56 unsigned long 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 longs is
107 * [-2147483648..2147483647] and the input base is 10,
108 * cutoff will be set to 214748364 and cutlim to either
109 * 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated
110 * a value > 214748364, or equal but the next digit is > 7 (or 8),
111 * the number is too big, and we will return a range error.
112 *
113 * Set 'any' if any `digits' consumed; make it negative to indicate
114 * overflow.
115 */
116 cutoff = neg ? (unsigned long)-(LONG_MIN + LONG_MAX) + LONG_MAX
117 : LONG_MAX;
118 cutlim = cutoff % base;
119 cutoff /= base;
120 for ( ; ; c = *s++) {
121 if (c >= '0' && c <= '9')
122 c -= '0';
123 else if (c >= 'A' && c <= 'Z')
124 c -= 'A' - 10;
125 else if (c >= 'a' && c <= 'z')
126 c -= 'a' - 10;
127 else
128 break;
129 if (c >= base)
130 break;
131 if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
132 any = -1;
133 else {
134 any = 1;
135 acc *= base;
136 acc += c;
137 }
138 }
139 if (any < 0) {
140 acc = neg ? LONG_MIN : LONG_MAX;
141 errno = ERANGE;
142 } else if (!any) {
143 noconv:
144 errno = EINVAL;
145 } else if (neg)
146 acc = -acc;
147 if (endptr != NULL)
148 *endptr = (char *)(any ? s - 1 : nptr);
149 return (acc);
150 }
151 long
strtol(const char * __restrict nptr,char ** __restrict endptr,int base)152 strtol(const char * __restrict nptr, char ** __restrict endptr, int base)
153 {
154 return strtol_l(nptr, endptr, base, __get_locale());
155 }
156