xref: /illumos-gate/usr/src/lib/libc/port/i18n/wcstoul.c (revision c77843b01543b72a167a9899efe84a9743d98ab8)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1986 AT&T	*/
28 /*	  All Rights Reserved  	*/
29 
30 #ifndef	_WCS_LONGLONG
31 #pragma weak _wcstoul = wcstoul
32 #endif
33 
34 #include "lint.h"
35 #include <limits.h>
36 #include <errno.h>
37 #include <wchar.h>
38 #define	DIGIT(x)	(iswdigit(x) ? (x) - L'0' : \
39 			iswlower(x) ? (x) + 10 - L'a' : (x) + 10 - L'A')
40 #define	MBASE	(L'z' - L'a' + 1 + 10)
41 
42 #ifdef	_WCS_LONGLONG
43 #define	_WULONG_T	unsigned long long
44 #define	_WULONG_MAX	ULLONG_MAX
45 #else  /* _WCS_LONGLONG */
46 #define	_WULONG_T	unsigned long
47 #define	_WULONG_MAX	ULONG_MAX
48 #endif /* _WCS_LONGLONG */
49 
50 #ifdef	_WCS_LONGLONG
51 unsigned long long
52 wcstoull(const wchar_t *_RESTRICT_KYWD str, wchar_t **_RESTRICT_KYWD ptr,
53     int base)
54 #else /* _WCS_LONGLONG */
55 unsigned long
56 wcstoul(const wchar_t *str, wchar_t **ptr, int base)
57 #endif /* _WCS_LONGLONG */
58 {
59 	_WULONG_T	val;
60 	wchar_t	c;
61 	int	xx, neg = 0;
62 	_WULONG_T	multmax;
63 
64 	if (ptr != NULL)
65 		*ptr = (wchar_t *)str; /* in case no number is formed */
66 	if (base < 0 || base > MBASE) {
67 		errno = EINVAL;
68 		return (0); /* base is invalid -- should be a fatal error */
69 	}
70 
71 	if (!iswalnum(c = *str)) {
72 		while (iswspace(c)) {
73 			c = *++str;
74 		}
75 		switch (c) {
76 		case L'-':
77 			neg++;
78 			/*FALLTHRU*/
79 		case L'+':
80 			c = *++str;
81 		}
82 	}
83 	if (base == 0) {
84 		if (c != L'0')
85 			base = 10;
86 		else if (str[1] == L'x' || str[1] == L'X')
87 			base = 16;
88 		else
89 			base = 8;
90 	}
91 	/*
92 	 * for any base > 10, the digits incrementally following
93 	 *	9 are assumed to be "abc...z" or "ABC...Z"
94 	 */
95 	if (!iswalnum(c) || (xx = DIGIT(c)) >= base) {
96 		errno = EINVAL;
97 		return (0); /* no number formed */
98 	}
99 	if (base == 16 && c == L'0' && iswxdigit(str[2]) &&
100 	    (str[1] == L'x' || str[1] == L'X')) {
101 		c = *(str += 2); /* skip over leading "0x" or "0X" */
102 	}
103 
104 	multmax = _WULONG_MAX / (_WULONG_T)base;
105 	val = DIGIT(c);
106 	for (; iswalnum(c = *++str) && (xx = DIGIT(c)) < base; ) {
107 		/* accumulate neg avoids surprises near MAXLONG */
108 		if (val > multmax)
109 			goto overflow;
110 		val *= base;
111 		if (_WULONG_MAX - val < xx)
112 			goto overflow;
113 		val += xx;
114 	}
115 	if (ptr != NULL)
116 		*ptr = (wchar_t *)str;
117 	return (neg ? -val : val);
118 
119 overflow:
120 	while (iswalnum(c = *++str) && (xx = DIGIT(c)) < base)
121 		;
122 
123 	if (ptr != NULL)
124 		*ptr = (wchar_t *)str;
125 	errno = ERANGE;
126 	return (_WULONG_MAX);
127 }
128