xref: /netbsd-src/common/lib/libc/stdlib/_strtol.h (revision af56d1fe9956bd7c616e18c1b7f025f464618471)
1 /* $NetBSD: _strtol.h,v 1.5 2013/04/16 21:44:06 joerg 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  * Original version ID:
32  * NetBSD: src/lib/libc/locale/_wcstol.h,v 1.2 2003/08/07 16:43:03 agc Exp
33  */
34 
35 /*
36  * function template for strtol, strtoll and strtoimax.
37  *
38  * parameters:
39  *	_FUNCNAME : function name
40  *      __INT     : return type
41  *      __INT_MIN : lower limit of the return type
42  *      __INT_MAX : upper limit of the return type
43  */
44 #if defined(_KERNEL) || defined(_STANDALONE) || defined(HAVE_NBTOOL_CONFIG_H)
45 __INT
46 _FUNCNAME(const char *nptr, char **endptr, int base)
47 #else
48 #include <locale.h>
49 #include "setlocale_local.h"
50 #define INT_FUNCNAME_(pre, name, post)	pre ## name ## post
51 #define INT_FUNCNAME(pre, name, post)	INT_FUNCNAME_(pre, name, post)
52 
53 static __INT
54 INT_FUNCNAME(_int_, _FUNCNAME, _l)(const char *nptr, char **endptr,
55 				   int base, locale_t loc)
56 #endif
57 {
58 	const char *s;
59 	__INT acc, cutoff;
60 	unsigned char c;
61 	int i, neg, any, cutlim;
62 
63 	_DIAGASSERT(nptr != NULL);
64 	/* endptr may be NULL */
65 
66 	/* check base value */
67 	if (base && (base < 2 || base > 36)) {
68 #if !defined(_KERNEL) && !defined(_STANDALONE)
69 		errno = EINVAL;
70 		if (endptr != NULL)
71 			/* LINTED interface specification */
72 			*endptr = __UNCONST(nptr);
73 		return 0;
74 #else
75 		panic("%s: invalid base %d", __func__, base);
76 #endif
77 	}
78 
79 	/*
80 	 * Skip white space and pick up leading +/- sign if any.
81 	 * If base is 0, allow 0x for hex and 0 for octal, else
82 	 * assume decimal; if base is already 16, allow 0x.
83 	 */
84 	s = nptr;
85 #if defined(_KERNEL) || defined(_STANDALONE) || defined(HAVE_NBTOOL_CONFIG_H)
86 	do {
87 		c = *s++;
88 	} while (isspace(c));
89 #else
90 	do {
91 		c = *s++;
92 	} while (isspace_l(c, loc));
93 #endif
94 	if (c == '-') {
95 		neg = 1;
96 		c = *s++;
97 	} else {
98 		neg = 0;
99 		if (c == '+')
100 			c = *s++;
101 	}
102 	if ((base == 0 || base == 16) &&
103 	    c == '0' && (*s == 'x' || *s == 'X')) {
104 		c = s[1];
105 		s += 2;
106 		base = 16;
107 	}
108 	if (base == 0)
109 		base = (c == '0' ? 8 : 10);
110 
111 	/*
112 	 * Compute the cutoff value between legal numbers and illegal
113 	 * numbers.  That is the largest legal value, divided by the
114 	 * base.  An input number that is greater than this value, if
115 	 * followed by a legal input character, is too big.  One that
116 	 * is equal to this value may be valid or not; the limit
117 	 * between valid and invalid numbers is then based on the last
118 	 * digit.  For instance, if the range for longs is
119 	 * [-2147483648..2147483647] and the input base is 10,
120 	 * cutoff will be set to 214748364 and cutlim to either
121 	 * 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated
122 	 * a value > 214748364, or equal but the next digit is > 7 (or 8),
123 	 * the number is too big, and we will return a range error.
124 	 *
125 	 * Set any if any `digits' consumed; make it negative to indicate
126 	 * overflow.
127 	 */
128 	cutoff = (__INT)(neg ? __INT_MIN : __INT_MAX);
129 	cutlim = (int)(cutoff % base);
130 	cutoff /= base;
131 	if (neg) {
132 		if (cutlim > 0) {
133 			cutlim -= base;
134 			cutoff += 1;
135 		}
136 		cutlim = -cutlim;
137 	}
138 	for (acc = 0, any = 0;; c = *s++) {
139 		if (c >= '0' && c <= '9')
140 			i = c - '0';
141 		else if (c >= 'a' && c <= 'z')
142 			i = (c - 'a') + 10;
143 		else if (c >= 'A' && c <= 'Z')
144 			i = (c - 'A') + 10;
145 		else
146 			break;
147 		if (i >= base)
148 			break;
149 		if (any < 0)
150 			continue;
151 		if (neg) {
152 			if (acc < cutoff || (acc == cutoff && i > cutlim)) {
153 				acc = __INT_MIN;
154 #if !defined(_KERNEL) && !defined(_STANDALONE)
155 				any = -1;
156 				errno = ERANGE;
157 #else
158 				any = 0;
159 				break;
160 #endif
161 			} else {
162 				any = 1;
163 				acc *= base;
164 				acc -= i;
165 			}
166 		} else {
167 			if (acc > cutoff || (acc == cutoff && i > cutlim)) {
168 				acc = __INT_MAX;
169 #if !defined(_KERNEL) && !defined(_STANDALONE)
170 				any = -1;
171 				errno = ERANGE;
172 #else
173 				any = 0;
174 				break;
175 #endif
176 			} else {
177 				any = 1;
178 				acc *= base;
179 				acc += i;
180 			}
181 		}
182 	}
183 	if (endptr != NULL)
184 		/* LINTED interface specification */
185 		*endptr = __UNCONST(any ? s - 1 : nptr);
186 	return(acc);
187 }
188 
189 #if !defined(_KERNEL) && !defined(_STANDALONE) && !defined(HAVE_NBTOOL_CONFIG_H)
190 __INT
191 _FUNCNAME(const char *nptr, char **endptr, int base)
192 {
193 	return INT_FUNCNAME(_int_, _FUNCNAME, _l)(nptr, endptr, base, *_current_locale());
194 }
195 
196 __INT
197 INT_FUNCNAME(, _FUNCNAME, _l)(const char *nptr, char **endptr, int base, locale_t loc)
198 {
199 	if (loc == NULL)
200 		loc = _C_locale;
201 	return INT_FUNCNAME(_int_, _FUNCNAME, _l)(nptr, endptr, base, loc);
202 }
203 #endif
204