2000-08-29 Michael Snyder <msnyder@seadog.cygnus.com>
[binutils.git] / libiberty / strtol.c
blobc05d0dd76a2e6428385ffbd7e3c271550efadffd
1 /*-
2 * Copyright (c) 1990 The Regents of the University of California.
3 * All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. [rescinded 22 July 1999]
14 * 4. Neither the name of the University nor the names of its contributors
15 * may be used to endorse or promote products derived from this software
16 * without specific prior written permission.
18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
31 #ifdef HAVE_CONFIG_H
32 #include "config.h"
33 #endif
34 #ifdef HAVE_LIMITS_H
35 #include <limits.h>
36 #endif
37 #ifdef HAVE_SYS_PARAM_H
38 #include <sys/param.h>
39 #endif
40 #include <ctype.h>
41 #include <errno.h>
42 #ifdef NEED_DECLARATION_ERRNO
43 extern int errno;
44 #endif
45 #if 0
46 #include <stdlib.h>
47 #endif
48 #include "ansidecl.h"
50 /* FIXME: It'd be nice to configure around these, but the include files are too
51 painful. These macros should at least be more portable than hardwired hex
52 constants. */
54 #ifndef ULONG_MAX
55 #define ULONG_MAX ((unsigned long)(~0L)) /* 0xFFFFFFFF */
56 #endif
58 #ifndef LONG_MAX
59 #define LONG_MAX ((long)(ULONG_MAX >> 1)) /* 0x7FFFFFFF */
60 #endif
62 #ifndef LONG_MIN
63 #define LONG_MIN ((long)(~LONG_MAX)) /* 0x80000000 */
64 #endif
67 * Convert a string to a long integer.
69 * Ignores `locale' stuff. Assumes that the upper and lower case
70 * alphabets and digits are each contiguous.
72 long
73 strtol(nptr, endptr, base)
74 const char *nptr;
75 char **endptr;
76 register int base;
78 register const char *s = nptr;
79 register unsigned long acc;
80 register int c;
81 register unsigned long cutoff;
82 register int neg = 0, any, cutlim;
85 * Skip white space and pick up leading +/- sign if any.
86 * If base is 0, allow 0x for hex and 0 for octal, else
87 * assume decimal; if base is already 16, allow 0x.
89 do {
90 c = *s++;
91 } while (isspace(c));
92 if (c == '-') {
93 neg = 1;
94 c = *s++;
95 } else if (c == '+')
96 c = *s++;
97 if ((base == 0 || base == 16) &&
98 c == '0' && (*s == 'x' || *s == 'X')) {
99 c = s[1];
100 s += 2;
101 base = 16;
103 if (base == 0)
104 base = c == '0' ? 8 : 10;
107 * Compute the cutoff value between legal numbers and illegal
108 * numbers. That is the largest legal value, divided by the
109 * base. An input number that is greater than this value, if
110 * followed by a legal input character, is too big. One that
111 * is equal to this value may be valid or not; the limit
112 * between valid and invalid numbers is then based on the last
113 * digit. For instance, if the range for longs is
114 * [-2147483648..2147483647] and the input base is 10,
115 * cutoff will be set to 214748364 and cutlim to either
116 * 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated
117 * a value > 214748364, or equal but the next digit is > 7 (or 8),
118 * the number is too big, and we will return a range error.
120 * Set any if any `digits' consumed; make it negative to indicate
121 * overflow.
123 cutoff = neg ? -(unsigned long)LONG_MIN : LONG_MAX;
124 cutlim = cutoff % (unsigned long)base;
125 cutoff /= (unsigned long)base;
126 for (acc = 0, any = 0;; c = *s++) {
127 if (isdigit(c))
128 c -= '0';
129 else if (isalpha(c))
130 c -= isupper(c) ? 'A' - 10 : 'a' - 10;
131 else
132 break;
133 if (c >= base)
134 break;
135 if (any < 0 || acc > cutoff || acc == cutoff && c > cutlim)
136 any = -1;
137 else {
138 any = 1;
139 acc *= base;
140 acc += c;
143 if (any < 0) {
144 acc = neg ? LONG_MIN : LONG_MAX;
145 errno = ERANGE;
146 } else if (neg)
147 acc = -acc;
148 if (endptr != 0)
149 *endptr = (char *) (any ? s - 1 : nptr);
150 return (acc);