xref: /netbsd-src/common/lib/libc/stdlib/strtoumax.c (revision bfb6cb13d599546df69c7e4d20d70e22e15a549d)
1 /*	$NetBSD: strtoumax.c,v 1.1 2006/04/22 15:33:33 thorpej Exp $	*/
2 
3 /*
4  * Copyright (c) 1990, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #if !defined(_KERNEL) && !defined(_STANDALONE)
33 #include <sys/cdefs.h>
34 #if defined(LIBC_SCCS) && !defined(lint)
35 #if 0
36 static char sccsid[] = "from: @(#)strtoul.c	8.1 (Berkeley) 6/4/93";
37 #else
38 __RCSID("$NetBSD: strtoumax.c,v 1.1 2006/04/22 15:33:33 thorpej Exp $");
39 #endif
40 #endif /* LIBC_SCCS and not lint */
41 
42 #include "namespace.h"
43 
44 #include <assert.h>
45 #include <ctype.h>
46 #include <errno.h>
47 #include <inttypes.h>
48 #include <stddef.h>
49 
50 #ifdef __weak_alias
51 __weak_alias(strtoumax, _strtoumax)
52 #endif
53 
54 #else /* !_KERNEL && !_STANDALONE */
55 #include <sys/param.h>
56 #include <lib/libkern/libkern.h>
57 #endif /* !_KERNEL && !_STANDALONE */
58 
59 /*
60  * Convert a string to an uintmax_t.
61  *
62  * Ignores `locale' stuff.  Assumes that the upper and lower case
63  * alphabets and digits are each contiguous.
64  */
65 uintmax_t
66 strtoumax(nptr, endptr, base)
67 	const char *nptr;
68 	char **endptr;
69 	int base;
70 {
71 	const char *s;
72 	uintmax_t acc, cutoff;
73 	int c;
74 	int neg, any, cutlim;
75 
76 	_DIAGASSERT(nptr != NULL);
77 	/* endptr may be NULL */
78 
79 	/*
80 	 * See strtol for comments as to the logic used.
81 	 */
82 	s = nptr;
83 	do {
84 		c = (unsigned char) *s++;
85 	} while (isspace(c));
86 	if (c == '-') {
87 		neg = 1;
88 		c = *s++;
89 	} else {
90 		neg = 0;
91 		if (c == '+')
92 			c = *s++;
93 	}
94 	if ((base == 0 || base == 16) &&
95 	    c == '0' && (*s == 'x' || *s == 'X')) {
96 		c = s[1];
97 		s += 2;
98 		base = 16;
99 	}
100 	if (base == 0)
101 		base = c == '0' ? 8 : 10;
102 
103 	cutoff = UINTMAX_MAX / (uintmax_t)base;
104 	cutlim = (int)(UINTMAX_MAX % (uintmax_t)base);
105 	for (acc = 0, any = 0;; c = (unsigned char) *s++) {
106 		if (isdigit(c))
107 			c -= '0';
108 		else if (isalpha(c)) {
109 #if defined(_KERNEL) || defined(_STANDALONE)
110 			c = toupper(c) - 'A' + 10;
111 #else
112 			c -= isupper(c) ? 'A' - 10 : 'a' - 10;
113 #endif
114 		} else
115 			break;
116 		if (c >= base)
117 			break;
118 		if (any < 0)
119 			continue;
120 		if (acc > cutoff || (acc == cutoff && c > cutlim)) {
121 #if defined(_KERNEL) || defined(_STANDALONE)
122 			if (endptr)
123 				*endptr = __UNCONST(nptr);
124 			return UINTMAX_MAX;
125 #else
126 			any = -1;
127 			acc = UINTMAX_MAX;
128 			errno = ERANGE;
129 #endif
130 		} else {
131 			any = 1;
132 			acc *= (uintmax_t)base;
133 			acc += c;
134 		}
135 	}
136 	if (neg && any > 0)
137 		acc = -acc;
138 	if (endptr != 0)
139 		*endptr = __UNCONST(any ? s - 1 : nptr);
140 	return (acc);
141 }
142