xref: /freebsd/lib/libc/stdlib/strtoumax.c (revision dc36d6f9bb1753f3808552f3afd30eda9a7b206a)
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 a uintmax_t integer.
45  *
46  * Assumes that the upper and lower case
47  * alphabets and digits are each contiguous.
48  */
49 uintmax_t
strtoumax_l(const char * __restrict nptr,char ** __restrict endptr,int base,locale_t locale)50 strtoumax_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 	 * See strtoimax for comments as to the logic used.
62 	 */
63 	s = nptr;
64 	do {
65 		c = *s++;
66 	} while (isspace_l((unsigned char)c, locale));
67 	if (c == '-') {
68 		neg = 1;
69 		c = *s++;
70 	} else {
71 		neg = 0;
72 		if (c == '+')
73 			c = *s++;
74 	}
75 	if ((base == 0 || base == 16) &&
76 	    c == '0' && (*s == 'x' || *s == 'X') &&
77 	    ((s[1] >= '0' && s[1] <= '9') ||
78 	    (s[1] >= 'A' && s[1] <= 'F') ||
79 	    (s[1] >= 'a' && s[1] <= 'f'))) {
80 		c = s[1];
81 		s += 2;
82 		base = 16;
83 	}
84 	if ((base == 0 || base == 2) &&
85 	    c == '0' && (*s == 'b' || *s == 'B') &&
86 	    (s[1] >= '0' && s[1] <= '1')) {
87 		c = s[1];
88 		s += 2;
89 		base = 2;
90 	}
91 	if (base == 0)
92 		base = c == '0' ? 8 : 10;
93 	acc = any = 0;
94 	if (base < 2 || base > 36)
95 		goto noconv;
96 
97 	cutoff = UINTMAX_MAX / base;
98 	cutlim = UINTMAX_MAX % base;
99 	for ( ; ; c = *s++) {
100 		if (c >= '0' && c <= '9')
101 			c -= '0';
102 		else if (c >= 'A' && c <= 'Z')
103 			c -= 'A' - 10;
104 		else if (c >= 'a' && c <= 'z')
105 			c -= 'a' - 10;
106 		else
107 			break;
108 		if (c >= base)
109 			break;
110 		if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
111 			any = -1;
112 		else {
113 			any = 1;
114 			acc *= base;
115 			acc += c;
116 		}
117 	}
118 	if (any < 0) {
119 		acc = UINTMAX_MAX;
120 		errno = ERANGE;
121 	} else if (!any) {
122 noconv:
123 		errno = EINVAL;
124 	} else if (neg)
125 		acc = -acc;
126 	if (endptr != NULL)
127 		*endptr = (char *)(any ? s - 1 : nptr);
128 	return (acc);
129 }
130 uintmax_t
strtoumax(const char * __restrict nptr,char ** __restrict endptr,int base)131 strtoumax(const char * __restrict nptr, char ** __restrict endptr, int base)
132 {
133 	return strtoumax_l(nptr, endptr, base, __get_locale());
134 }
135