lib/strtol.c

   1 /* Copyright (C) 1991, 92, 94, 95, 96 Free Software Foundation, Inc.
   2
   3 NOTE: The canonical source of this file is maintained with the GNU C Library.
   4 Bugs can be reported to bug-glibc@prep.ai.mit.edu.
   5
   6 This program is free software; you can redistribute it and/or modify it
   7 under the terms of the GNU General Public License as published by the
   8 Free Software Foundation; either version 2, or (at your option) any
   9 later version.
  10
  11 This program is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with this program; if not, write to the Free Software
  18 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  19 USA.  */
  20
  21 #ifdef HAVE_CONFIG_H
  22 # include <config.h>
  23 #endif
  24
  25 #ifdef _LIBC
  26 # define USE_NUMBER_GROUPING
  27 # define STDC_HEADERS
  28 # define HAVE_LIMITS_H
  29 #endif
  30
  31 #include <ctype.h>
  32 #include <errno.h>
  33 #ifndef errno
  34 extern int errno;
  35 #endif
  36
  37 #ifdef HAVE_LIMITS_H
  38 # include <limits.h>
  39 #endif
  40
  41 #ifdef STDC_HEADERS
  42 # include <stddef.h>
  43 # include <stdlib.h>
  44 #else
  45 # ifndef NULL
  46 #  define NULL 0
  47 # endif
  48 #endif
  49
  50 #ifdef USE_NUMBER_GROUPING
  51 # include "../locale/localeinfo.h"
  52 #endif
  53
  54 /* Nonzero if we are defining `strtoul' or `strtouq', operating on
  55    unsigned integers.  */
  56 #ifndef UNSIGNED
  57 # define UNSIGNED 0
  58 # define INT LONG int
  59 #else
  60 # define INT unsigned LONG int
  61 #endif
  62
  63 /* Determine the name.  */
  64 #if UNSIGNED
  65 # ifdef USE_WIDE_CHAR
  66 #  ifdef QUAD
  67 #   define strtol wcstouq
  68 #  else
  69 #   define strtol wcstoul
  70 #  endif
  71 # else
  72 #  ifdef QUAD
  73 #   define strtol strtouq
  74 #  else
  75 #   define strtol strtoul
  76 #  endif
  77 # endif
  78 #else
  79 # ifdef USE_WIDE_CHAR
  80 #  ifdef QUAD
  81 #   define strtol wcstoq
  82 #  else
  83 #   define strtol wcstol
  84 #  endif
  85 # else
  86 #  ifdef QUAD
  87 #   define strtol strtoq
  88 #  endif
  89 # endif
  90 #endif
  91
  92 /* If QUAD is defined, we are defining `strtoq' or `strtouq',
  93    operating on `long long int's.  */
  94 #ifdef QUAD
  95 # define LONG long long
  96 # undef LONG_MIN
  97 # define LONG_MIN LONG_LONG_MIN
  98 # undef LONG_MAX
  99 # define LONG_MAX LONG_LONG_MAX
 100 # undef ULONG_MAX
 101 # define ULONG_MAX ULONG_LONG_MAX
 102 # if __GNUC__ == 2 && __GNUC_MINOR__ < 7
 103    /* Work around gcc bug with using this constant.  */
 104    static const unsigned long long int maxquad = ULONG_LONG_MAX;
 105 #  undef ULONG_MAX
 106 #  define ULONG_MAX maxquad
 107 # endif
 108 #else
 109 # define LONG long
 110
 111 #ifndef ULONG_MAX
 112 # define ULONG_MAX ((unsigned long) ~(unsigned long) 0)
 113 #endif
 114 #ifndef LONG_MAX
 115 # define LONG_MAX ((long int) (ULONG_MAX >> 1))
 116 #endif
 117 #endif
 118
 119 #ifdef USE_WIDE_CHAR
 120 # include <wchar.h>
 121 # include <wctype.h>
 122 # define L_(ch) L##ch
 123 # define UCHAR_TYPE wint_t
 124 # define STRING_TYPE wchar_t
 125 # define ISSPACE(ch) iswspace (ch)
 126 # define ISALPHA(ch) iswalpha (ch)
 127 # define TOUPPER(ch) towupper (ch)
 128 #else
 129 # define L_(ch) ch
 130 # define UCHAR_TYPE unsigned char
 131 # define STRING_TYPE char
 132 # define ISSPACE(ch) isspace (ch)
 133 # define ISALPHA(ch) isalpha (ch)
 134 # define TOUPPER(ch) toupper (ch)
 135 #endif
 136
 137 #ifdef __STDC__
 138 # define INTERNAL(x) INTERNAL1(x)
 139 # define INTERNAL1(x) __##x##_internal
 140 # define WEAKNAME(x) WEAKNAME1(x)
 141 # define WEAKNAME1(x) __##x
 142 #else
 143 # define INTERNAL(x) __/**/x/**/_internal
 144 # define WEAKNAME(x) __/**/x
 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 (c != thousands && (c < L_('0') || c > L_('9'))
 255             && (!ISALPHA (c) || TOUPPER (c) - L_('A') + 10 >= base))
 256           break;
 257       if (*s == thousands)
 258         end = s;
 259       else
 260         end = correctly_grouped_prefix (s, end, thousands, grouping);
 261     }
 262   else
 263 #endif
 264     end = NULL;
 265
 266   cutoff = ULONG_MAX / (unsigned LONG int) base;
 267   cutlim = ULONG_MAX % (unsigned LONG int) base;
 268
 269   overflow = 0;
 270   i = 0;
 271   for (c = *s; c != L_('\0'); c = *++s)
 272     {
 273       if (s == end)
 274         break;
 275       if (c >= L_('0') && c <= L_('9'))
 276         c -= L_('0');
 277       else if (ISALPHA (c))
 278         c = TOUPPER (c) - L_('A') + 10;
 279       else
 280         break;
 281       if (c >= base)
 282         break;
 283       /* Check for overflow.  */
 284       if (i > cutoff || (i == cutoff && c > cutlim))
 285         overflow = 1;
 286       else
 287         {
 288           i *= (unsigned LONG int) base;
 289           i += c;
 290         }
 291     }
 292
 293   /* Check if anything actually happened.  */
 294   if (s == save)
 295     goto noconv;
 296
 297   /* Store in ENDPTR the address of one character
 298      past the last character we converted.  */
 299   if (endptr != NULL)
 300     *endptr = (STRING_TYPE *) s;
 301
 302 #if !UNSIGNED
 303   /* Check for a value that is within the range of
 304      `unsigned LONG int', but outside the range of `LONG int'.  */
 305   if (overflow == 0
 306       && i > (negative
 307               ? -((unsigned LONG int) (LONG_MIN + 1)) + 1
 308               : (unsigned LONG int) LONG_MAX))
 309     overflow = 1;
 310 #endif
 311
 312   if (overflow)
 313     {
 314       errno = ERANGE;
 315 #if UNSIGNED
 316       return ULONG_MAX;
 317 #else
 318       return negative ? LONG_MIN : LONG_MAX;
 319 #endif
 320     }
 321
 322   /* Return the result of the appropriate sign.  */
 323   return (negative ? -i : i);
 324
 325 noconv:
 326   /* We must handle a special case here: the base is 0 or 16 and the
 327      first two characters and '0' and 'x', but the rest are no
 328      hexadecimal digits.  This is no error case.  We return 0 and
 329      ENDPTR points to the `x`.  */
 330   if (endptr != NULL)
 331     if (save - nptr >= 2 && TOUPPER (save[-1]) == L_('X')
 332         && save[-2] == L_('0'))
 333       *endptr = (STRING_TYPE *) &save[-1];
 334     else
 335       /*  There was no number to convert.  */
 336       *endptr = (STRING_TYPE *) nptr;
 337
 338   return 0L;
 339 }
 340 \f
 341 /* External user entry point.  */
 342
 343 #undef __P
 344 #if defined (__STDC__) && __STDC__
 345 #define __P(args) args
 346 #else
 347 #define __P(args) ()
 348 #endif
 349
 350 /* Prototype.  */
 351 INT strtol __P ((const STRING_TYPE *nptr, STRING_TYPE **endptr,
 352                             int base));
 353
 354
 355 INT
 356 strtol (nptr, endptr, base)
 357      const STRING_TYPE *nptr;
 358      STRING_TYPE **endptr;
 359      int base;
 360 {
 361   return INTERNAL (strtol) (nptr, endptr, base, 0);
 362 }