compat/strtoll.c

   1 /*-
   2  * Copyright (c) 1990 The Regents of the University of California.
   3  * All rights reserved.
   4  *
   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. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. 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
  34 /* modified for long long <mgd@swarm.org> 1999-08-12 */
  35
  36 #include "squid.h"
  37 #include "compat/strtoll.h"
  38
  39 #if HAVE_CTYPE_H
  40 #include <ctype.h>
  41 #endif
  42 #if HAVE_ERRNO_H
  43 #include <errno.h>
  44 #endif
  45
  46
  47 #ifndef INT64_MIN
  48 /* Native 64 bit system without strtoll() */
  49 #if defined(LONG_MIN) && (SIZEOF_LONG == 8)
  50 #define INT64_MIN LONG_MIN
  51 #else
  52 /* 32 bit system */
  53 #define INT64_MIN       -9223372036854775807L-1L
  54 #endif
  55 #endif
  56
  57 #ifndef INT64_MAX
  58 /* Native 64 bit system without strtoll() */
  59 #if defined(LONG_MAX) && (SIZEOF_LONG == 8)
  60 #define INT64_MAX LONG_MAX
  61 #else
  62 /* 32 bit system */
  63 #define INT64_MAX       9223372036854775807L
  64 #endif
  65 #endif
  66
  67
  68 /*
  69  * Convert a string to a int64 integer.
  70  *
  71  * Ignores `locale' stuff.  Assumes that the upper and lower case
  72  * alphabets and digits are each contiguous.
  73  */
  74 int64_t
  75 strtoll (const char *nptr, char **endptr, int base)
  76 {
  77     register const char *s = nptr;
  78     register uint64_t acc;
  79     register int c;
  80     register uint64_t cutoff;
  81     register int neg = 0, any, cutlim;
  82
  83     /*
  84      * Skip white space and pick up leading +/- sign if any.
  85      * If base is 0, allow 0x for hex and 0 for octal, else
  86      * assume decimal; if base is already 16, allow 0x.
  87      */
  88     do {
  89         c = *s++;
  90     } while (xisspace(c));
  91     if (c == '-') {
  92         neg = 1;
  93         c = *s++;
  94     } else if (c == '+')
  95         c = *s++;
  96     if ((base == 0 || base == 16) && c == '0' && (*s == 'x' || *s == 'X')) {
  97         c = s[1];
  98         s += 2;
  99         base = 16;
 100     }
 101     if (base == 0)
 102         base = c == '0' ? 8 : 10;
 103
 104     /*
 105      * Compute the cutoff value between legal numbers and illegal
 106      * numbers.  That is the largest legal value, divided by the
 107      * base.  An input number that is greater than this value, if
 108      * followed by a legal input character, is too big.  One that
 109      * is equal to this value may be valid or not; the limit
 110      * between valid and invalid numbers is then based on the last
 111      * digit.  For instance, if the range for longs is
 112      * [-2147483648..2147483647] and the input base is 10,
 113      * cutoff will be set to 214748364 and cutlim to either
 114      * 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated
 115      * a value > 214748364, or equal but the next digit is > 7 (or 8),
 116      * the number is too big, and we will return a range error.
 117      *
 118      * Set any if any `digits' consumed; make it negative to indicate
 119      * overflow.
 120      */
 121     cutoff = neg ? -(uint64_t) INT64_MIN : INT64_MAX;
 122     cutlim = cutoff % (uint64_t) base;
 123     cutoff /= (uint64_t) base;
 124     for (acc = 0, any = 0;; c = *s++) {
 125         if (xisdigit(c))
 126             c -= '0';
 127         else if (xisalpha(c))
 128             c -= xisupper(c) ? 'A' - 10 : 'a' - 10;
 129         else
 130             break;
 131         if (c >= base)
 132             break;
 133         if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
 134             any = -1;
 135         else {
 136             any = 1;
 137             acc *= base;
 138             acc += c;
 139         }
 140     }
 141     if (any < 0) {
 142         acc = neg ? INT64_MIN : INT64_MAX;
 143         errno = ERANGE;
 144     } else if (neg)
 145         acc = -acc;
 146     if (endptr != 0)
 147         *endptr = (char *) (any ? s - 1 : nptr);
 148     return acc;
 149 }
 150