newlib/libc/stdlib/strtoll.c

   1 /*
   2 FUNCTION
   3    <<strtoll>>, <<strtoll_l>>---string to long long
   4
   5 INDEX
   6         strtoll
   7
   8 INDEX
   9         strtoll_l
  10
  11 INDEX
  12         _strtoll_r
  13
  14 SYNOPSIS
  15         #include <stdlib.h>
  16         long long strtoll(const char *restrict <[s]>, char **restrict <[ptr]>,
  17                           int <[base]>);
  18
  19         #include <stdlib.h>
  20         long long strtoll_l(const char *restrict <[s]>,
  21                             char **restrict <[ptr]>, int <[base]>,
  22                             locale_t <[locale]>);
  23
  24         long long _strtoll_r(void *<[reent]>,
  25                              const char *restrict <[s]>,
  26                              char **restrict <[ptr]>, int <[base]>);
  27
  28 DESCRIPTION
  29 The function <<strtoll>> converts the string <<*<[s]>>> to
  30 a <<long long>>. First, it breaks down the string into three parts:
  31 leading whitespace, which is ignored; a subject string consisting
  32 of characters resembling an integer in the radix specified by <[base]>;
  33 and a trailing portion consisting of zero or more unparseable characters,
  34 and always including the terminating null character. Then, it attempts
  35 to convert the subject string into a <<long long>> and returns the
  36 result.
  37
  38 If the value of <[base]> is 0, the subject string is expected to look
  39 like a normal C integer constant: an optional sign, a possible `<<0x>>'
  40 indicating a hexadecimal base, and a number. If <[base]> is between
  41 2 and 36, the expected form of the subject is a sequence of letters
  42 and digits representing an integer in the radix specified by <[base]>,
  43 with an optional plus or minus sign. The letters <<a>>--<<z>> (or,
  44 equivalently, <<A>>--<<Z>>) are used to signify values from 10 to 35;
  45 only letters whose ascribed values are less than <[base]> are
  46 permitted. If <[base]> is 16, a leading <<0x>> is permitted.
  47
  48 The subject sequence is the longest initial sequence of the input
  49 string that has the expected form, starting with the first
  50 non-whitespace character.  If the string is empty or consists entirely
  51 of whitespace, or if the first non-whitespace character is not a
  52 permissible letter or digit, the subject string is empty.
  53
  54 If the subject string is acceptable, and the value of <[base]> is zero,
  55 <<strtoll>> attempts to determine the radix from the input string. A
  56 string with a leading <<0x>> is treated as a hexadecimal value; a string with
  57 a leading 0 and no <<x>> is treated as octal; all other strings are
  58 treated as decimal. If <[base]> is between 2 and 36, it is used as the
  59 conversion radix, as described above. If the subject string begins with
  60 a minus sign, the value is negated. Finally, a pointer to the first
  61 character past the converted subject string is stored in <[ptr]>, if
  62 <[ptr]> is not <<NULL>>.
  63
  64 If the subject string is empty (or not in acceptable form), no conversion
  65 is performed and the value of <[s]> is stored in <[ptr]> (if <[ptr]> is
  66 not <<NULL>>).
  67
  68 <<strtoll_l>> is like <<strtoll>> but performs the conversion based on the
  69 locale specified by the locale object locale.  If <[locale]> is
  70 LC_GLOBAL_LOCALE or not a valid locale object, the behaviour is undefined.
  71
  72 The alternate function <<_strtoll_r>> is a reentrant version.  The
  73 extra argument <[reent]> is a pointer to a reentrancy structure.
  74
  75 RETURNS
  76 <<strtoll>>, <<strtoll_l>> return the converted value, if any. If no
  77 conversion was made, 0 is returned.
  78
  79 <<strtoll>>, <<strtoll_l>> return <<LONG_LONG_MAX>> or <<LONG_LONG_MIN>>
  80 if the magnitude of the converted value is too large, and sets <<errno>>
  81 to <<ERANGE>>.
  82
  83 PORTABILITY
  84 <<strtoll>> is ANSI.
  85 <<strtoll_l>> is a GNU extension.
  86
  87 No supporting OS subroutines are required.
  88 */
  89
  90 /*-
  91  * Copyright (c) 1990 The Regents of the University of California.
  92  * All rights reserved.
  93  *
  94  * Redistribution and use in source and binary forms, with or without
  95  * modification, are permitted provided that the following conditions
  96  * are met:
  97  * 1. Redistributions of source code must retain the above copyright
  98  *    notice, this list of conditions and the following disclaimer.
  99  * 2. Redistributions in binary form must reproduce the above copyright
 100  *    notice, this list of conditions and the following disclaimer in the
 101  *    documentation and/or other materials provided with the distribution.
 102  * 3. Neither the name of the University nor the names of its contributors
 103  *    may be used to endorse or promote products derived from this software
 104  *    without specific prior written permission.
 105  *
 106  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 107  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 108  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 109  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 110  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 111  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 112  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 113  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 114  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 115  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 116  * SUCH DAMAGE.
 117  */
 118
 119 #define _GNU_SOURCE
 120 #include <_ansi.h>
 121 #include <limits.h>
 122 #include <ctype.h>
 123 #include <errno.h>
 124 #include <stdlib.h>
 125 #include <reent.h>
 126 #include "../locale/setlocale.h"
 127
 128 /*
 129  * Convert a string to a long long integer.
 130  */
 131 static long long
 132 _strtoll_l (struct _reent *rptr, const char *__restrict nptr,
 133             char **__restrict endptr, int base, locale_t loc)
 134 {
 135         register const unsigned char *s = (const unsigned char *)nptr;
 136         register unsigned long long acc;
 137         register int c;
 138         register unsigned long long cutoff;
 139         register int neg = 0, any, cutlim;
 140
 141         /*
 142          * Skip white space and pick up leading +/- sign if any.
 143          * If base is 0, allow 0x for hex and 0 for octal, else
 144          * assume decimal; if base is already 16, allow 0x.
 145          */
 146         do {
 147                 c = *s++;
 148         } while (isspace_l(c, loc));
 149         if (c == '-') {
 150                 neg = 1;
 151                 c = *s++;
 152         } else if (c == '+')
 153                 c = *s++;
 154         if ((base == 0 || base == 16) &&
 155             c == '0' && (*s == 'x' || *s == 'X')) {
 156                 c = s[1];
 157                 s += 2;
 158                 base = 16;
 159         }
 160         if (base == 0)
 161                 base = c == '0' ? 8 : 10;
 162
 163         /*
 164          * Compute the cutoff value between legal numbers and illegal
 165          * numbers.  That is the largest legal value, divided by the
 166          * base.  An input number that is greater than this value, if
 167          * followed by a legal input character, is too big.  One that
 168          * is equal to this value may be valid or not; the limit
 169          * between valid and invalid numbers is then based on the last
 170          * digit.  For instance, if the range for longs is
 171          * [-2147483648..2147483647] and the input base is 10,
 172          * cutoff will be set to 214748364 and cutlim to either
 173          * 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated
 174          * a value > 214748364, or equal but the next digit is > 7 (or 8),
 175          * the number is too big, and we will return a range error.
 176          *
 177          * Set any if any `digits' consumed; make it negative to indicate
 178          * overflow.
 179          */
 180         cutoff = neg ? -(unsigned long long)LONG_LONG_MIN : LONG_LONG_MAX;
 181         cutlim = cutoff % (unsigned long long)base;
 182         cutoff /= (unsigned long long)base;
 183         for (acc = 0, any = 0;; c = *s++) {
 184                 if (c >= '0' && c <= '9')
 185                         c -= '0';
 186                 else if (c >= 'A' && c <= 'Z')
 187                         c -= 'A' - 10;
 188                 else if (c >= 'a' && c <= 'z')
 189                         c -= 'a' - 10;
 190                 else
 191                         break;
 192                 if (c >= base)
 193                         break;
 194                if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
 195                         any = -1;
 196                 else {
 197                         any = 1;
 198                         acc *= base;
 199                         acc += c;
 200                 }
 201         }
 202         if (any < 0) {
 203                 acc = neg ? LONG_LONG_MIN : LONG_LONG_MAX;
 204                 _REENT_ERRNO(rptr) = ERANGE;
 205         } else if (neg)
 206                 acc = -acc;
 207         if (endptr != 0)
 208                 *endptr = (char *) (any ? (char *)s - 1 : nptr);
 209         return (acc);
 210 }
 211
 212 long long
 213 _strtoll_r (struct _reent *rptr,
 214         const char *__restrict nptr,
 215         char **__restrict endptr,
 216         int base)
 217 {
 218         return _strtoll_l (rptr, nptr, endptr, base, __get_current_locale ());
 219 }
 220
 221 #ifndef _REENT_ONLY
 222
 223 long long
 224 strtoll_l (const char *__restrict s, char **__restrict ptr, int base,
 225            locale_t loc)
 226 {
 227         return _strtoll_l (_REENT, s, ptr, base, loc);
 228 }
 229
 230 long long
 231 strtoll (const char *__restrict s,
 232         char **__restrict ptr,
 233         int base)
 234 {
 235         return _strtoll_l (_REENT, s, ptr, base, __get_current_locale ());
 236 }
 237
 238 #endif