newlib/libc/stdlib/strtoull.c

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