2004-11-06 Michael Koch <konqueror@gmx.de>
[official-gcc.git] / libiberty / strtol.c
blobd9f54cc8f7ac23e13cce3dd241dab43860792e31
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 [rescinded 22 July 1999]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.
33 @deftypefn Supplemental {long int} strtol (const char *@var{string}, char **@var{endptr}, int @var{base})
34 @deftypefnx Supplemental {unsigned long int} strtoul (const char *@var{string}, char **@var{endptr}, int @var{base})
36 The @code{strtol} function converts the string in @var{string} to a
37 long integer value according to the given @var{base}, which must be
38 between 2 and 36 inclusive, or be the special value 0. If @var{base}
39 is 0, @code{strtol} will look for the prefixes @code{0} and @code{0x}
40 to indicate bases 8 and 16, respectively, else default to base 10.
41 When the base is 16 (either explicitly or implicitly), a prefix of
42 @code{0x} is allowed. The handling of @var{endptr} is as that of
43 @code{strtod} above. The @code{strtoul} function is the same, except
44 that the converted value is unsigned.
46 @end deftypefn
50 #ifdef HAVE_CONFIG_H
51 #include "config.h"
52 #endif
53 #ifdef HAVE_LIMITS_H
54 #include <limits.h>
55 #endif
56 #ifdef HAVE_SYS_PARAM_H
57 #include <sys/param.h>
58 #endif
59 #include <errno.h>
60 #ifdef NEED_DECLARATION_ERRNO
61 extern int errno;
62 #endif
63 #include "safe-ctype.h"
65 /* FIXME: It'd be nice to configure around these, but the include files are too
66 painful. These macros should at least be more portable than hardwired hex
67 constants. */
69 #ifndef ULONG_MAX
70 #define ULONG_MAX ((unsigned long)(~0L)) /* 0xFFFFFFFF */
71 #endif
73 #ifndef LONG_MAX
74 #define LONG_MAX ((long)(ULONG_MAX >> 1)) /* 0x7FFFFFFF */
75 #endif
77 #ifndef LONG_MIN
78 #define LONG_MIN ((long)(~LONG_MAX)) /* 0x80000000 */
79 #endif
82 * Convert a string to a long integer.
84 * Ignores `locale' stuff. Assumes that the upper and lower case
85 * alphabets and digits are each contiguous.
87 long
88 strtol(nptr, endptr, base)
89 const char *nptr;
90 char **endptr;
91 register int base;
93 register const char *s = nptr;
94 register unsigned long acc;
95 register int c;
96 register unsigned long cutoff;
97 register int neg = 0, any, cutlim;
100 * Skip white space and pick up leading +/- sign if any.
101 * If base is 0, allow 0x for hex and 0 for octal, else
102 * assume decimal; if base is already 16, allow 0x.
104 do {
105 c = *s++;
106 } while (ISSPACE(c));
107 if (c == '-') {
108 neg = 1;
109 c = *s++;
110 } else if (c == '+')
111 c = *s++;
112 if ((base == 0 || base == 16) &&
113 c == '0' && (*s == 'x' || *s == 'X')) {
114 c = s[1];
115 s += 2;
116 base = 16;
118 if (base == 0)
119 base = c == '0' ? 8 : 10;
122 * Compute the cutoff value between legal numbers and illegal
123 * numbers. That is the largest legal value, divided by the
124 * base. An input number that is greater than this value, if
125 * followed by a legal input character, is too big. One that
126 * is equal to this value may be valid or not; the limit
127 * between valid and invalid numbers is then based on the last
128 * digit. For instance, if the range for longs is
129 * [-2147483648..2147483647] and the input base is 10,
130 * cutoff will be set to 214748364 and cutlim to either
131 * 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated
132 * a value > 214748364, or equal but the next digit is > 7 (or 8),
133 * the number is too big, and we will return a range error.
135 * Set any if any `digits' consumed; make it negative to indicate
136 * overflow.
138 cutoff = neg ? -(unsigned long)LONG_MIN : LONG_MAX;
139 cutlim = cutoff % (unsigned long)base;
140 cutoff /= (unsigned long)base;
141 for (acc = 0, any = 0;; c = *s++) {
142 if (ISDIGIT(c))
143 c -= '0';
144 else if (ISALPHA(c))
145 c -= ISUPPER(c) ? 'A' - 10 : 'a' - 10;
146 else
147 break;
148 if (c >= base)
149 break;
150 if (any < 0 || acc > cutoff || acc == cutoff && c > cutlim)
151 any = -1;
152 else {
153 any = 1;
154 acc *= base;
155 acc += c;
158 if (any < 0) {
159 acc = neg ? LONG_MIN : LONG_MAX;
160 errno = ERANGE;
161 } else if (neg)
162 acc = -acc;
163 if (endptr != 0)
164 *endptr = (char *) (any ? s - 1 : nptr);
165 return (acc);