1 /* $NetBSD: _strtoul.h,v 1.1 2008/08/20 12:42:26 joerg Exp $ */
2
3 /*-
4 * SPDX-License-Identifier: BSD-3-Clause
5 *
6 * Copyright (c) 1990, 1993
7 * The Regents of the University of California. All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 * Original version ID:
34 * NetBSD: src/lib/libc/locale/_wcstoul.h,v 1.2 2003/08/07 16:43:03 agc Exp
35 */
36
37 /*
38 * function template for strtoul, strtoull and strtoumax.
39 *
40 * parameters:
41 * _FUNCNAME : function name
42 * __UINT : return type
43 * __UINT_MAX : upper limit of the return type
44 */
45
46 __UINT
_FUNCNAME(const char * nptr,char ** endptr,int base)47 _FUNCNAME(const char *nptr, char **endptr, int base)
48 {
49 const char *s;
50 __UINT acc, cutoff;
51 unsigned char c;
52 int any, cutlim, i, neg;
53
54 /* check base value */
55 if (base && (base < 2 || base > 36)) {
56 #if !defined(_KERNEL) && !defined(_STANDALONE)
57 errno = EINVAL;
58 return (0);
59 #else
60 panic("%s: invalid base %d", __func__, base);
61 #endif
62 }
63
64 /*
65 * Skip white space and pick up leading +/- sign if any.
66 * If base is 0, allow 0x for hex and 0 for octal, else
67 * assume decimal; if base is already 16, allow 0x.
68 */
69 s = nptr;
70 do {
71 c = *s++;
72 } while (isspace(c));
73 if (c == '-') {
74 neg = 1;
75 c = *s++;
76 } else {
77 neg = 0;
78 if (c == '+')
79 c = *s++;
80 }
81 if ((base == 0 || base == 16) &&
82 c == '0' && (*s == 'x' || *s == 'X') &&
83 ((s[1] >= '0' && s[1] <= '9') ||
84 (s[1] >= 'A' && s[1] <= 'F') ||
85 (s[1] >= 'a' && s[1] <= 'f'))) {
86 c = s[1];
87 s += 2;
88 base = 16;
89 }
90 if ((base == 0 || base == 2) &&
91 c == '0' && (*s == 'b' || *s == 'B') &&
92 (s[1] >= '0' && s[1] <= '1')) {
93 c = s[1];
94 s += 2;
95 base = 2;
96 }
97 if (base == 0)
98 base = (c == '0' ? 8 : 10);
99
100 /*
101 * See strtol for comments as to the logic used.
102 */
103 cutoff = __UINT_MAX / (__UINT)base;
104 cutlim = (int)(__UINT_MAX % (__UINT)base);
105 for (acc = 0, any = 0;; c = *s++) {
106 if (isdigit(c))
107 i = c - '0';
108 else if (isalpha(c))
109 i = c - (isupper(c) ? 'A' - 10 : 'a' - 10);
110 else
111 break;
112 if (i >= base)
113 break;
114 if (any < 0)
115 continue;
116 if (acc > cutoff || (acc == cutoff && i > cutlim)) {
117 acc = __UINT_MAX;
118 #if !defined(_KERNEL) && !defined(_STANDALONE)
119 any = -1;
120 errno = ERANGE;
121 #else
122 any = 0;
123 break;
124 #endif
125 } else {
126 any = 1;
127 acc *= (__UINT)base;
128 acc += i;
129 }
130 }
131 if (neg && any > 0)
132 acc = -acc;
133 if (endptr != NULL)
134 /* LINTED interface specification */
135 *endptr = __DECONST(void *, any ? s - 1 : nptr);
136 return (acc);
137 }
138