code.delx.au - gnu-emacs/blob - lib/strtol.c

   1 /* Convert string representation of a number into an integer value.
   2
   3    Copyright (C) 1991-1992, 1994-1999, 2003, 2005-2007, 2009-2011 Free Software
   4    Foundation, Inc.
   5
   6    NOTE: The canonical source of this file is maintained with the GNU C
   7    Library.  Bugs can be reported to bug-glibc@gnu.org.
   8
   9    This program is free software: you can redistribute it and/or modify it
  10    under the terms of the GNU General Public License as published by the
  11    Free Software Foundation; either version 3 of the License, or any
  12    later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  21
  22 #ifdef _LIBC
  23 # define USE_NUMBER_GROUPING
  24 #else
  25 # include <config.h>
  26 #endif
  27
  28 #include <ctype.h>
  29 #include <errno.h>
  30 #ifndef __set_errno
  31 # define __set_errno(Val) errno = (Val)
  32 #endif
  33
  34 #include <limits.h>
  35 #include <stddef.h>
  36 #include <stdlib.h>
  37 #include <string.h>
  38
  39 #ifdef USE_NUMBER_GROUPING
  40 # include "../locale/localeinfo.h"
  41 #endif
  42
  43 /* Nonzero if we are defining `strtoul' or `strtoull', operating on
  44    unsigned integers.  */
  45 #ifndef UNSIGNED
  46 # define UNSIGNED 0
  47 # define INT LONG int
  48 #else
  49 # define INT unsigned LONG int
  50 #endif
  51
  52 /* Determine the name.  */
  53 #ifdef USE_IN_EXTENDED_LOCALE_MODEL
  54 # if UNSIGNED
  55 #  ifdef USE_WIDE_CHAR
  56 #   ifdef QUAD
  57 #    define strtol __wcstoull_l
  58 #   else
  59 #    define strtol __wcstoul_l
  60 #   endif
  61 #  else
  62 #   ifdef QUAD
  63 #    define strtol __strtoull_l
  64 #   else
  65 #    define strtol __strtoul_l
  66 #   endif
  67 #  endif
  68 # else
  69 #  ifdef USE_WIDE_CHAR
  70 #   ifdef QUAD
  71 #    define strtol __wcstoll_l
  72 #   else
  73 #    define strtol __wcstol_l
  74 #   endif
  75 #  else
  76 #   ifdef QUAD
  77 #    define strtol __strtoll_l
  78 #   else
  79 #    define strtol __strtol_l
  80 #   endif
  81 #  endif
  82 # endif
  83 #else
  84 # if UNSIGNED
  85 #  ifdef USE_WIDE_CHAR
  86 #   ifdef QUAD
  87 #    define strtol wcstoull
  88 #   else
  89 #    define strtol wcstoul
  90 #   endif
  91 #  else
  92 #   ifdef QUAD
  93 #    define strtol strtoull
  94 #   else
  95 #    define strtol strtoul
  96 #   endif
  97 #  endif
  98 # else
  99 #  ifdef USE_WIDE_CHAR
 100 #   ifdef QUAD
 101 #    define strtol wcstoll
 102 #   else
 103 #    define strtol wcstol
 104 #   endif
 105 #  else
 106 #   ifdef QUAD
 107 #    define strtol strtoll
 108 #   endif
 109 #  endif
 110 # endif
 111 #endif
 112
 113 /* If QUAD is defined, we are defining `strtoll' or `strtoull',
 114    operating on `long long int's.  */
 115 #ifdef QUAD
 116 # define LONG long long
 117 # define STRTOL_LONG_MIN LLONG_MIN
 118 # define STRTOL_LONG_MAX LLONG_MAX
 119 # define STRTOL_ULONG_MAX ULLONG_MAX
 120
 121 /* The extra casts in the following macros work around compiler bugs,
 122    e.g., in Cray C 5.0.3.0.  */
 123
 124 /* True if negative values of the signed integer type T use two's
 125    complement, ones' complement, or signed magnitude representation,
 126    respectively.  Much GNU code assumes two's complement, but some
 127    people like to be portable to all possible C hosts.  */
 128 # define TYPE_TWOS_COMPLEMENT(t) ((t) ~ (t) 0 == (t) -1)
 129 # define TYPE_ONES_COMPLEMENT(t) ((t) ~ (t) 0 == 0)
 130 # define TYPE_SIGNED_MAGNITUDE(t) ((t) ~ (t) 0 < (t) -1)
 131
 132 /* True if the arithmetic type T is signed.  */
 133 # define TYPE_SIGNED(t) (! ((t) 0 < (t) -1))
 134
 135 /* The maximum and minimum values for the integer type T.  These
 136    macros have undefined behavior if T is signed and has padding bits.
 137    If this is a problem for you, please let us know how to fix it for
 138    your host.  */
 139 # define TYPE_MINIMUM(t) \
 140    ((t) (! TYPE_SIGNED (t) \
 141          ? (t) 0 \
 142          : TYPE_SIGNED_MAGNITUDE (t) \
 143          ? ~ (t) 0 \
 144          : ~ TYPE_MAXIMUM (t)))
 145 # define TYPE_MAXIMUM(t) \
 146    ((t) (! TYPE_SIGNED (t) \
 147          ? (t) -1 \
 148          : ((((t) 1 << (sizeof (t) * CHAR_BIT - 2)) - 1) * 2 + 1)))
 149
 150 # ifndef ULLONG_MAX
 151 #  define ULLONG_MAX TYPE_MAXIMUM (unsigned long long)
 152 # endif
 153 # ifndef LLONG_MAX
 154 #  define LLONG_MAX TYPE_MAXIMUM (long long int)
 155 # endif
 156 # ifndef LLONG_MIN
 157 #  define LLONG_MIN TYPE_MINIMUM (long long int)
 158 # endif
 159
 160 # if __GNUC__ == 2 && __GNUC_MINOR__ < 7
 161    /* Work around gcc bug with using this constant.  */
 162    static const unsigned long long int maxquad = ULLONG_MAX;
 163 #  undef STRTOL_ULONG_MAX
 164 #  define STRTOL_ULONG_MAX maxquad
 165 # endif
 166 #else
 167 # define LONG long
 168 # define STRTOL_LONG_MIN LONG_MIN
 169 # define STRTOL_LONG_MAX LONG_MAX
 170 # define STRTOL_ULONG_MAX ULONG_MAX
 171 #endif
 172
 173
 174 /* We use this code also for the extended locale handling where the
 175    function gets as an additional argument the locale which has to be
 176    used.  To access the values we have to redefine the _NL_CURRENT
 177    macro.  */
 178 #ifdef USE_IN_EXTENDED_LOCALE_MODEL
 179 # undef _NL_CURRENT
 180 # define _NL_CURRENT(category, item) \
 181   (current->values[_NL_ITEM_INDEX (item)].string)
 182 # define LOCALE_PARAM , loc
 183 # define LOCALE_PARAM_PROTO , __locale_t loc
 184 #else
 185 # define LOCALE_PARAM
 186 # define LOCALE_PARAM_PROTO
 187 #endif
 188
 189 #include <wchar.h>
 190
 191 #ifdef USE_WIDE_CHAR
 192 # include <wctype.h>
 193 # define L_(Ch) L##Ch
 194 # define UCHAR_TYPE wint_t
 195 # define STRING_TYPE wchar_t
 196 # ifdef USE_IN_EXTENDED_LOCALE_MODEL
 197 #  define ISSPACE(Ch) __iswspace_l ((Ch), loc)
 198 #  define ISALPHA(Ch) __iswalpha_l ((Ch), loc)
 199 #  define TOUPPER(Ch) __towupper_l ((Ch), loc)
 200 # else
 201 #  define ISSPACE(Ch) iswspace (Ch)
 202 #  define ISALPHA(Ch) iswalpha (Ch)
 203 #  define TOUPPER(Ch) towupper (Ch)
 204 # endif
 205 #else
 206 # define L_(Ch) Ch
 207 # define UCHAR_TYPE unsigned char
 208 # define STRING_TYPE char
 209 # ifdef USE_IN_EXTENDED_LOCALE_MODEL
 210 #  define ISSPACE(Ch) __isspace_l ((Ch), loc)
 211 #  define ISALPHA(Ch) __isalpha_l ((Ch), loc)
 212 #  define TOUPPER(Ch) __toupper_l ((Ch), loc)
 213 # else
 214 #  define ISSPACE(Ch) isspace (Ch)
 215 #  define ISALPHA(Ch) isalpha (Ch)
 216 #  define TOUPPER(Ch) toupper (Ch)
 217 # endif
 218 #endif
 219
 220 #define INTERNAL(X) INTERNAL1(X)
 221 #define INTERNAL1(X) __##X##_internal
 222 #define WEAKNAME(X) WEAKNAME1(X)
 223
 224 #ifdef USE_NUMBER_GROUPING
 225 /* This file defines a function to check for correct grouping.  */
 226 # include "grouping.h"
 227 #endif
 228
 229
 230
 231 /* Convert NPTR to an `unsigned long int' or `long int' in base BASE.
 232    If BASE is 0 the base is determined by the presence of a leading
 233    zero, indicating octal or a leading "0x" or "0X", indicating hexadecimal.
 234    If BASE is < 2 or > 36, it is reset to 10.
 235    If ENDPTR is not NULL, a pointer to the character after the last
 236    one converted is stored in *ENDPTR.  */
 237
 238 INT
 239 INTERNAL (strtol) (const STRING_TYPE *nptr, STRING_TYPE **endptr,
 240                    int base, int group LOCALE_PARAM_PROTO)
 241 {
 242   int negative;
 243   register unsigned LONG int cutoff;
 244   register unsigned int cutlim;
 245   register unsigned LONG int i;
 246   register const STRING_TYPE *s;
 247   register UCHAR_TYPE c;
 248   const STRING_TYPE *save, *end;
 249   int overflow;
 250
 251 #ifdef USE_NUMBER_GROUPING
 252 # ifdef USE_IN_EXTENDED_LOCALE_MODEL
 253   struct locale_data *current = loc->__locales[LC_NUMERIC];
 254 # endif
 255   /* The thousands character of the current locale.  */
 256   wchar_t thousands = L'\0';
 257   /* The numeric grouping specification of the current locale,
 258      in the format described in <locale.h>.  */
 259   const char *grouping;
 260
 261   if (group)
 262     {
 263       grouping = _NL_CURRENT (LC_NUMERIC, GROUPING);
 264       if (*grouping <= 0 || *grouping == CHAR_MAX)
 265         grouping = NULL;
 266       else
 267         {
 268           /* Figure out the thousands separator character.  */
 269 # if defined _LIBC || defined _HAVE_BTOWC
 270           thousands = __btowc (*_NL_CURRENT (LC_NUMERIC, THOUSANDS_SEP));
 271           if (thousands == WEOF)
 272             thousands = L'\0';
 273 # endif
 274           if (thousands == L'\0')
 275             grouping = NULL;
 276         }
 277     }
 278   else
 279     grouping = NULL;
 280 #endif
 281
 282   if (base < 0 || base == 1 || base > 36)
 283     {
 284       __set_errno (EINVAL);
 285       return 0;
 286     }
 287
 288   save = s = nptr;
 289
 290   /* Skip white space.  */
 291   while (ISSPACE (*s))
 292     ++s;
 293   if (*s == L_('\0'))
 294     goto noconv;
 295
 296   /* Check for a sign.  */
 297   if (*s == L_('-'))
 298     {
 299       negative = 1;
 300       ++s;
 301     }
 302   else if (*s == L_('+'))
 303     {
 304       negative = 0;
 305       ++s;
 306     }
 307   else
 308     negative = 0;
 309
 310   /* Recognize number prefix and if BASE is zero, figure it out ourselves.  */
 311   if (*s == L_('0'))
 312     {
 313       if ((base == 0 || base == 16) && TOUPPER (s[1]) == L_('X'))
 314         {
 315           s += 2;
 316           base = 16;
 317         }
 318       else if (base == 0)
 319         base = 8;
 320     }
 321   else if (base == 0)
 322     base = 10;
 323
 324   /* Save the pointer so we can check later if anything happened.  */
 325   save = s;
 326
 327 #ifdef USE_NUMBER_GROUPING
 328   if (group)
 329     {
 330       /* Find the end of the digit string and check its grouping.  */
 331       end = s;
 332       for (c = *end; c != L_('\0'); c = *++end)
 333         if ((wchar_t) c != thousands
 334             && ((wchar_t) c < L_('0') || (wchar_t) c > L_('9'))
 335             && (!ISALPHA (c) || (int) (TOUPPER (c) - L_('A') + 10) >= base))
 336           break;
 337       if (*s == thousands)
 338         end = s;
 339       else
 340         end = correctly_grouped_prefix (s, end, thousands, grouping);
 341     }
 342   else
 343 #endif
 344     end = NULL;
 345
 346   cutoff = STRTOL_ULONG_MAX / (unsigned LONG int) base;
 347   cutlim = STRTOL_ULONG_MAX % (unsigned LONG int) base;
 348
 349   overflow = 0;
 350   i = 0;
 351   for (c = *s; c != L_('\0'); c = *++s)
 352     {
 353       if (s == end)
 354         break;
 355       if (c >= L_('0') && c <= L_('9'))
 356         c -= L_('0');
 357       else if (ISALPHA (c))
 358         c = TOUPPER (c) - L_('A') + 10;
 359       else
 360         break;
 361       if ((int) c >= base)
 362         break;
 363       /* Check for overflow.  */
 364       if (i > cutoff || (i == cutoff && c > cutlim))
 365         overflow = 1;
 366       else
 367         {
 368           i *= (unsigned LONG int) base;
 369           i += c;
 370         }
 371     }
 372
 373   /* Check if anything actually happened.  */
 374   if (s == save)
 375     goto noconv;
 376
 377   /* Store in ENDPTR the address of one character
 378      past the last character we converted.  */
 379   if (endptr != NULL)
 380     *endptr = (STRING_TYPE *) s;
 381
 382 #if !UNSIGNED
 383   /* Check for a value that is within the range of
 384      `unsigned LONG int', but outside the range of `LONG int'.  */
 385   if (overflow == 0
 386       && i > (negative
 387               ? -((unsigned LONG int) (STRTOL_LONG_MIN + 1)) + 1
 388               : (unsigned LONG int) STRTOL_LONG_MAX))
 389     overflow = 1;
 390 #endif
 391
 392   if (overflow)
 393     {
 394       __set_errno (ERANGE);
 395 #if UNSIGNED
 396       return STRTOL_ULONG_MAX;
 397 #else
 398       return negative ? STRTOL_LONG_MIN : STRTOL_LONG_MAX;
 399 #endif
 400     }
 401
 402   /* Return the result of the appropriate sign.  */
 403   return negative ? -i : i;
 404
 405 noconv:
 406   /* We must handle a special case here: the base is 0 or 16 and the
 407      first two characters are '0' and 'x', but the rest are no
 408      hexadecimal digits.  This is no error case.  We return 0 and
 409      ENDPTR points to the `x`.  */
 410   if (endptr != NULL)
 411     {
 412       if (save - nptr >= 2 && TOUPPER (save[-1]) == L_('X')
 413           && save[-2] == L_('0'))
 414         *endptr = (STRING_TYPE *) &save[-1];
 415       else
 416         /*  There was no number to convert.  */
 417         *endptr = (STRING_TYPE *) nptr;
 418     }
 419
 420   return 0L;
 421 }
 422 \f
 423 /* External user entry point.  */
 424
 425
 426 INT
 427 #ifdef weak_function
 428 weak_function
 429 #endif
 430 strtol (const STRING_TYPE *nptr, STRING_TYPE **endptr,
 431         int base LOCALE_PARAM_PROTO)
 432 {
 433   return INTERNAL (strtol) (nptr, endptr, base, 0 LOCALE_PARAM);
 434 }