stdlib/strtol.c

   1 /* Copyright (C) 1991, 92, 94, 95, 96 Free Software Foundation, Inc.
   2 This file is part of the GNU C Library.
   3
   4 The GNU C Library is free software; you can redistribute it and/or
   5 modify it under the terms of the GNU Library General Public License as
   6 published by the Free Software Foundation; either version 2 of the
   7 License, or (at your option) any later version.
   8
   9 The GNU C Library is distributed in the hope that it will be useful,
  10 but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12 Library General Public License for more details.
  13
  14 You should have received a copy of the GNU Library General Public
  15 License along with the GNU C Library; see the file COPYING.LIB.  If
  16 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  17 Cambridge, MA 02139, USA.  */
  18
  19 #ifdef HAVE_CONFIG_H
  20 # include <config.h>
  21 #endif
  22
  23 #ifdef _LIBC
  24 # define USE_NUMBER_GROUPING
  25 # define STDC_HEADERS
  26 # define HAVE_LIMITS_H
  27 #endif
  28
  29 #include <ctype.h>
  30 #include <errno.h>
  31 #ifndef errno
  32 extern int errno;
  33 #endif
  34 #ifndef __set_errno
  35 # define __set_errno(val) errno = (val)
  36 #endif
  37
  38 #ifdef HAVE_LIMITS_H
  39 # include <limits.h>
  40 #endif
  41
  42 #ifdef STDC_HEADERS
  43 # include <stddef.h>
  44 # include <stdlib.h>
  45 # include <string.h>
  46 #else
  47 # ifndef NULL
  48 #  define NULL 0
  49 # endif
  50 #endif
  51
  52 #ifdef USE_NUMBER_GROUPING
  53 # include "../locale/localeinfo.h"
  54 #endif
  55
  56 /* Nonzero if we are defining `strtoul' or `strtouq', operating on
  57    unsigned integers.  */
  58 #ifndef UNSIGNED
  59 # define UNSIGNED 0
  60 # define INT LONG int
  61 #else
  62 # define INT unsigned LONG int
  63 #endif
  64
  65 /* Determine the name.  */
  66 #if UNSIGNED
  67 # ifdef USE_WIDE_CHAR
  68 #  ifdef QUAD
  69 #   define strtol wcstouq
  70 #  else
  71 #   define strtol wcstoul
  72 #  endif
  73 # else
  74 #  ifdef QUAD
  75 #   define strtol strtouq
  76 #  else
  77 #   define strtol strtoul
  78 #  endif
  79 # endif
  80 #else
  81 # ifdef USE_WIDE_CHAR
  82 #  ifdef QUAD
  83 #   define strtol wcstoq
  84 #  else
  85 #   define strtol wcstol
  86 #  endif
  87 # else
  88 #  ifdef QUAD
  89 #   define strtol strtoq
  90 #  endif
  91 # endif
  92 #endif
  93
  94 /* If QUAD is defined, we are defining `strtoq' or `strtouq',
  95    operating on `long long int's.  */
  96 #ifdef QUAD
  97 # define LONG long long
  98 # undef LONG_MIN
  99 # define LONG_MIN LONG_LONG_MIN
 100 # undef LONG_MAX
 101 # define LONG_MAX LONG_LONG_MAX
 102 # undef ULONG_MAX
 103 # define ULONG_MAX ULONG_LONG_MAX
 104 # if __GNUC__ == 2 && __GNUC_MINOR__ < 7
 105    /* Work around gcc bug with using this constant.  */
 106    static const unsigned long long int maxquad = ULONG_LONG_MAX;
 107 #  undef ULONG_MAX
 108 #  define ULONG_MAX maxquad
 109 # endif
 110 #else
 111 # define LONG long
 112
 113 #ifndef ULONG_MAX
 114 # define ULONG_MAX ((unsigned long) ~(unsigned long) 0)
 115 #endif
 116 #ifndef LONG_MAX
 117 # define LONG_MAX ((long int) (ULONG_MAX >> 1))
 118 #endif
 119 #endif
 120
 121 #ifdef USE_WIDE_CHAR
 122 # include <wchar.h>
 123 # include <wctype.h>
 124 # define L_(ch) L##ch
 125 # define UCHAR_TYPE wint_t
 126 # define STRING_TYPE wchar_t
 127 # define ISSPACE(ch) iswspace (ch)
 128 # define ISALPHA(ch) iswalpha (ch)
 129 # define TOUPPER(ch) towupper (ch)
 130 #else
 131 # define L_(ch) ch
 132 # define UCHAR_TYPE unsigned char
 133 # define STRING_TYPE char
 134 # define ISSPACE(ch) isspace (ch)
 135 # define ISALPHA(ch) isalpha (ch)
 136 # define TOUPPER(ch) toupper (ch)
 137 #endif
 138
 139 #ifdef __STDC__
 140 # define INTERNAL(x) INTERNAL1(x)
 141 # define INTERNAL1(x) __##x##_internal
 142 # define WEAKNAME(x) WEAKNAME1(x)
 143 #else
 144 # define INTERNAL(x) __/**/x/**/_internal
 145 #endif
 146
 147 #ifdef USE_NUMBER_GROUPING
 148 /* This file defines a function to check for correct grouping.  */
 149 # include "grouping.h"
 150 #endif
 151
 152
 153 /* Convert NPTR to an `unsigned long int' or `long int' in base BASE.
 154    If BASE is 0 the base is determined by the presence of a leading
 155    zero, indicating octal or a leading "0x" or "0X", indicating hexadecimal.
 156    If BASE is < 2 or > 36, it is reset to 10.
 157    If ENDPTR is not NULL, a pointer to the character after the last
 158    one converted is stored in *ENDPTR.  */
 159
 160 INT
 161 INTERNAL (strtol) (nptr, endptr, base, group)
 162      const STRING_TYPE *nptr;
 163      STRING_TYPE **endptr;
 164      int base;
 165      int group;
 166 {
 167   int negative;
 168   register unsigned LONG int cutoff;
 169   register unsigned int cutlim;
 170   register unsigned LONG int i;
 171   register const STRING_TYPE *s;
 172   register UCHAR_TYPE c;
 173   const STRING_TYPE *save, *end;
 174   int overflow;
 175
 176 #ifdef USE_NUMBER_GROUPING
 177   /* The thousands character of the current locale.  */
 178   wchar_t thousands;
 179   /* The numeric grouping specification of the current locale,
 180      in the format described in <locale.h>.  */
 181   const char *grouping;
 182
 183   if (group)
 184     {
 185       grouping = _NL_CURRENT (LC_NUMERIC, GROUPING);
 186       if (*grouping <= 0 || *grouping == CHAR_MAX)
 187         grouping = NULL;
 188       else
 189         {
 190           /* Figure out the thousands separator character.  */
 191           if (mbtowc (&thousands, _NL_CURRENT (LC_NUMERIC, THOUSANDS_SEP),
 192                       strlen (_NL_CURRENT (LC_NUMERIC, THOUSANDS_SEP))) <= 0)
 193             thousands = (wchar_t) *_NL_CURRENT (LC_NUMERIC, THOUSANDS_SEP);
 194           if (thousands == L'\0')
 195             grouping = NULL;
 196         }
 197     }
 198   else
 199     grouping = NULL;
 200 #endif
 201
 202   if (base < 0 || base == 1 || base > 36)
 203     base = 10;
 204
 205   save = s = nptr;
 206
 207   /* Skip white space.  */
 208   while (ISSPACE (*s))
 209     ++s;
 210   if (*s == L_('\0'))
 211     goto noconv;
 212
 213   /* Check for a sign.  */
 214   if (*s == L_('-'))
 215     {
 216       negative = 1;
 217       ++s;
 218     }
 219   else if (*s == L_('+'))
 220     {
 221       negative = 0;
 222       ++s;
 223     }
 224   else
 225     negative = 0;
 226
 227   if (base == 16 && s[0] == L_('0') && TOUPPER (s[1]) == L_('X'))
 228     s += 2;
 229
 230   /* If BASE is zero, figure it out ourselves.  */
 231   if (base == 0)
 232     if (*s == L_('0'))
 233       {
 234         if (TOUPPER (s[1]) == L_('X'))
 235           {
 236             s += 2;
 237             base = 16;
 238           }
 239         else
 240           base = 8;
 241       }
 242     else
 243       base = 10;
 244
 245   /* Save the pointer so we can check later if anything happened.  */
 246   save = s;
 247
 248 #ifdef USE_NUMBER_GROUPING
 249   if (group)
 250     {
 251       /* Find the end of the digit string and check its grouping.  */
 252       end = s;
 253       for (c = *end; c != L_('\0'); c = *++end)
 254         if ((wchar_t) c != thousands
 255             && ((wchar_t) c < L_('0') || (wchar_t) c > L_('9'))
 256             && (!ISALPHA (c) || (int) (TOUPPER (c) - L_('A') + 10) >= base))
 257           break;
 258       if (*s == thousands)
 259         end = s;
 260       else
 261         end = correctly_grouped_prefix (s, end, thousands, grouping);
 262     }
 263   else
 264 #endif
 265     end = NULL;
 266
 267   cutoff = ULONG_MAX / (unsigned LONG int) base;
 268   cutlim = ULONG_MAX % (unsigned LONG int) base;
 269
 270   overflow = 0;
 271   i = 0;
 272   for (c = *s; c != L_('\0'); c = *++s)
 273     {
 274       if (s == end)
 275         break;
 276       if (c >= L_('0') && c <= L_('9'))
 277         c -= L_('0');
 278       else if (ISALPHA (c))
 279         c = TOUPPER (c) - L_('A') + 10;
 280       else
 281         break;
 282       if ((int) c >= base)
 283         break;
 284       /* Check for overflow.  */
 285       if (i > cutoff || (i == cutoff && c > cutlim))
 286         overflow = 1;
 287       else
 288         {
 289           i *= (unsigned LONG int) base;
 290           i += c;
 291         }
 292     }
 293
 294   /* Check if anything actually happened.  */
 295   if (s == save)
 296     goto noconv;
 297
 298   /* Store in ENDPTR the address of one character
 299      past the last character we converted.  */
 300   if (endptr != NULL)
 301     *endptr = (STRING_TYPE *) s;
 302
 303 #if !UNSIGNED
 304   /* Check for a value that is within the range of
 305      `unsigned LONG int', but outside the range of `LONG int'.  */
 306   if (overflow == 0
 307       && i > (negative
 308               ? -((unsigned LONG int) (LONG_MIN + 1)) + 1
 309               : (unsigned LONG int) LONG_MAX))
 310     overflow = 1;
 311 #endif
 312
 313   if (overflow)
 314     {
 315       __set_errno (ERANGE);
 316 #if UNSIGNED
 317       return ULONG_MAX;
 318 #else
 319       return negative ? LONG_MIN : LONG_MAX;
 320 #endif
 321     }
 322
 323   /* Return the result of the appropriate sign.  */
 324   return (negative ? -i : i);
 325
 326 noconv:
 327   /* We must handle a special case here: the base is 0 or 16 and the
 328      first two characters are '0' and 'x', but the rest are no
 329      hexadecimal digits.  This is no error case.  We return 0 and
 330      ENDPTR points to the `x`.  */
 331   if (endptr != NULL)
 332     if (save - nptr >= 2 && TOUPPER (save[-1]) == L_('X')
 333         && save[-2] == L_('0'))
 334       *endptr = (STRING_TYPE *) &save[-1];
 335     else
 336       /*  There was no number to convert.  */
 337       *endptr = (STRING_TYPE *) nptr;
 338
 339   return 0L;
 340 }
 341 \f
 342 /* External user entry point.  */
 343 INT
 344 #ifdef weak_function
 345 weak_function
 346 #endif
 347 strtol (nptr, endptr, base)
 348      const STRING_TYPE *nptr;
 349      STRING_TYPE **endptr;
 350      int base;
 351 {
 352   return INTERNAL (strtol) (nptr, endptr, base, 0);
 353 }