xref: /freebsd/lib/libc/stdlib/strtoumax.c (revision d0b2dbfa0ecf2bbc9709efc5e20baf8e4b44bbbf)
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 #if defined(LIBC_SCCS) && !defined(lint)
38 static char sccsid[] = "from @(#)strtoul.c	8.1 (Berkeley) 6/4/93";
39 #endif /* LIBC_SCCS and not lint */
40 #include <sys/cdefs.h>
41 #include <ctype.h>
42 #include <errno.h>
43 #include <stdlib.h>
44 #include <inttypes.h>
45 #include "xlocale_private.h"
46 
47 /*
48  * Convert a string to a uintmax_t integer.
49  *
50  * Assumes that the upper and lower case
51  * alphabets and digits are each contiguous.
52  */
53 uintmax_t
54 strtoumax_l(const char * __restrict nptr, char ** __restrict endptr, int base,
55 		locale_t locale)
56 {
57 	const char *s;
58 	uintmax_t acc;
59 	char c;
60 	uintmax_t cutoff;
61 	int neg, any, cutlim;
62 	FIX_LOCALE(locale);
63 
64 	/*
65 	 * See strtoimax for comments as to the logic used.
66 	 */
67 	s = nptr;
68 	do {
69 		c = *s++;
70 	} while (isspace_l((unsigned char)c, locale));
71 	if (c == '-') {
72 		neg = 1;
73 		c = *s++;
74 	} else {
75 		neg = 0;
76 		if (c == '+')
77 			c = *s++;
78 	}
79 	if ((base == 0 || base == 16) &&
80 	    c == '0' && (*s == 'x' || *s == 'X') &&
81 	    ((s[1] >= '0' && s[1] <= '9') ||
82 	    (s[1] >= 'A' && s[1] <= 'F') ||
83 	    (s[1] >= 'a' && s[1] <= 'f'))) {
84 		c = s[1];
85 		s += 2;
86 		base = 16;
87 	}
88 	if (base == 0)
89 		base = c == '0' ? 8 : 10;
90 	acc = any = 0;
91 	if (base < 2 || base > 36)
92 		goto noconv;
93 
94 	cutoff = UINTMAX_MAX / base;
95 	cutlim = UINTMAX_MAX % base;
96 	for ( ; ; c = *s++) {
97 		if (c >= '0' && c <= '9')
98 			c -= '0';
99 		else if (c >= 'A' && c <= 'Z')
100 			c -= 'A' - 10;
101 		else if (c >= 'a' && c <= 'z')
102 			c -= 'a' - 10;
103 		else
104 			break;
105 		if (c >= base)
106 			break;
107 		if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
108 			any = -1;
109 		else {
110 			any = 1;
111 			acc *= base;
112 			acc += c;
113 		}
114 	}
115 	if (any < 0) {
116 		acc = UINTMAX_MAX;
117 		errno = ERANGE;
118 	} else if (!any) {
119 noconv:
120 		errno = EINVAL;
121 	} else if (neg)
122 		acc = -acc;
123 	if (endptr != NULL)
124 		*endptr = (char *)(any ? s - 1 : nptr);
125 	return (acc);
126 }
127 uintmax_t
128 strtoumax(const char * __restrict nptr, char ** __restrict endptr, int base)
129 {
130 	return strtoumax_l(nptr, endptr, base, __get_locale());
131 }
132