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, 2009-2017 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 <https://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 the arithmetic type T is signed.  */
 125 # define TYPE_SIGNED(t) (! ((t) 0 < (t) -1))
 126
 127 /* Minimum and maximum values for integer types.
 128    These macros have undefined behavior for signed types that either
 129    have padding bits or do not use two's complement.  If this is a
 130    problem for you, please let us know how to fix it for your host.  */
 131
 132 /* The maximum and minimum values for the integer type T.  */
 133 # define TYPE_MINIMUM(t) ((t) ~ TYPE_MAXIMUM (t))
 134 # define TYPE_MAXIMUM(t)                                                 \
 135    ((t) (! TYPE_SIGNED (t)                                               \
 136          ? (t) -1                                                        \
 137          : ((((t) 1 << (sizeof (t) * CHAR_BIT - 2)) - 1) * 2 + 1)))
 138
 139 # ifndef ULLONG_MAX
 140 #  define ULLONG_MAX TYPE_MAXIMUM (unsigned long long)
 141 # endif
 142 # ifndef LLONG_MAX
 143 #  define LLONG_MAX TYPE_MAXIMUM (long long int)
 144 # endif
 145 # ifndef LLONG_MIN
 146 #  define LLONG_MIN TYPE_MINIMUM (long long int)
 147 # endif
 148
 149 # if __GNUC__ == 2 && __GNUC_MINOR__ < 7
 150    /* Work around gcc bug with using this constant.  */
 151    static const unsigned long long int maxquad = ULLONG_MAX;
 152 #  undef STRTOL_ULONG_MAX
 153 #  define STRTOL_ULONG_MAX maxquad
 154 # endif
 155 #else
 156 # define LONG long
 157 # define STRTOL_LONG_MIN LONG_MIN
 158 # define STRTOL_LONG_MAX LONG_MAX
 159 # define STRTOL_ULONG_MAX ULONG_MAX
 160 #endif
 161
 162
 163 /* We use this code also for the extended locale handling where the
 164    function gets as an additional argument the locale which has to be
 165    used.  To access the values we have to redefine the _NL_CURRENT
 166    macro.  */
 167 #ifdef USE_IN_EXTENDED_LOCALE_MODEL
 168 # undef _NL_CURRENT
 169 # define _NL_CURRENT(category, item) \
 170   (current->values[_NL_ITEM_INDEX (item)].string)
 171 # define LOCALE_PARAM , loc
 172 # define LOCALE_PARAM_PROTO , __locale_t loc
 173 #else
 174 # define LOCALE_PARAM
 175 # define LOCALE_PARAM_PROTO
 176 #endif
 177
 178 #ifdef USE_WIDE_CHAR
 179 # include <wchar.h>
 180 # include <wctype.h>
 181 # define L_(Ch) L##Ch
 182 # define UCHAR_TYPE wint_t
 183 # define STRING_TYPE wchar_t
 184 # ifdef USE_IN_EXTENDED_LOCALE_MODEL
 185 #  define ISSPACE(Ch) __iswspace_l ((Ch), loc)
 186 #  define ISALPHA(Ch) __iswalpha_l ((Ch), loc)
 187 #  define TOUPPER(Ch) __towupper_l ((Ch), loc)
 188 # else
 189 #  define ISSPACE(Ch) iswspace (Ch)
 190 #  define ISALPHA(Ch) iswalpha (Ch)
 191 #  define TOUPPER(Ch) towupper (Ch)
 192 # endif
 193 #else
 194 # define L_(Ch) Ch
 195 # define UCHAR_TYPE unsigned char
 196 # define STRING_TYPE char
 197 # ifdef USE_IN_EXTENDED_LOCALE_MODEL
 198 #  define ISSPACE(Ch) __isspace_l ((Ch), loc)
 199 #  define ISALPHA(Ch) __isalpha_l ((Ch), loc)
 200 #  define TOUPPER(Ch) __toupper_l ((Ch), loc)
 201 # else
 202 #  define ISSPACE(Ch) isspace (Ch)
 203 #  define ISALPHA(Ch) isalpha (Ch)
 204 #  define TOUPPER(Ch) toupper (Ch)
 205 # endif
 206 #endif
 207
 208 #define INTERNAL(X) INTERNAL1(X)
 209 #define INTERNAL1(X) __##X##_internal
 210 #define WEAKNAME(X) WEAKNAME1(X)
 211
 212 #ifdef USE_NUMBER_GROUPING
 213 /* This file defines a function to check for correct grouping.  */
 214 # include "grouping.h"
 215 #endif
 216
 217
 218
 219 /* Convert NPTR to an 'unsigned long int' or 'long int' in base BASE.
 220    If BASE is 0 the base is determined by the presence of a leading
 221    zero, indicating octal or a leading "0x" or "0X", indicating hexadecimal.
 222    If BASE is < 2 or > 36, it is reset to 10.
 223    If ENDPTR is not NULL, a pointer to the character after the last
 224    one converted is stored in *ENDPTR.  */
 225
 226 INT
 227 INTERNAL (strtol) (const STRING_TYPE *nptr, STRING_TYPE **endptr,
 228                    int base, int group LOCALE_PARAM_PROTO)
 229 {
 230   int negative;
 231   register unsigned LONG int cutoff;
 232   register unsigned int cutlim;
 233   register unsigned LONG int i;
 234   register const STRING_TYPE *s;
 235   register UCHAR_TYPE c;
 236   const STRING_TYPE *save, *end;
 237   int overflow;
 238
 239 #ifdef USE_NUMBER_GROUPING
 240 # ifdef USE_IN_EXTENDED_LOCALE_MODEL
 241   struct locale_data *current = loc->__locales[LC_NUMERIC];
 242 # endif
 243   /* The thousands character of the current locale.  */
 244   wchar_t thousands = L'\0';
 245   /* The numeric grouping specification of the current locale,
 246      in the format described in <locale.h>.  */
 247   const char *grouping;
 248
 249   if (group)
 250     {
 251       grouping = _NL_CURRENT (LC_NUMERIC, GROUPING);
 252       if (*grouping <= 0 || *grouping == CHAR_MAX)
 253         grouping = NULL;
 254       else
 255         {
 256           /* Figure out the thousands separator character.  */
 257 # if defined _LIBC || defined _HAVE_BTOWC
 258           thousands = __btowc (*_NL_CURRENT (LC_NUMERIC, THOUSANDS_SEP));
 259           if (thousands == WEOF)
 260             thousands = L'\0';
 261 # endif
 262           if (thousands == L'\0')
 263             grouping = NULL;
 264         }
 265     }
 266   else
 267     grouping = NULL;
 268 #endif
 269
 270   if (base < 0 || base == 1 || base > 36)
 271     {
 272       __set_errno (EINVAL);
 273       return 0;
 274     }
 275
 276   save = s = nptr;
 277
 278   /* Skip white space.  */
 279   while (ISSPACE (*s))
 280     ++s;
 281   if (*s == L_('\0'))
 282     goto noconv;
 283
 284   /* Check for a sign.  */
 285   if (*s == L_('-'))
 286     {
 287       negative = 1;
 288       ++s;
 289     }
 290   else if (*s == L_('+'))
 291     {
 292       negative = 0;
 293       ++s;
 294     }
 295   else
 296     negative = 0;
 297
 298   /* Recognize number prefix and if BASE is zero, figure it out ourselves.  */
 299   if (*s == L_('0'))
 300     {
 301       if ((base == 0 || base == 16) && TOUPPER (s[1]) == L_('X'))
 302         {
 303           s += 2;
 304           base = 16;
 305         }
 306       else if (base == 0)
 307         base = 8;
 308     }
 309   else if (base == 0)
 310     base = 10;
 311
 312   /* Save the pointer so we can check later if anything happened.  */
 313   save = s;
 314
 315 #ifdef USE_NUMBER_GROUPING
 316   if (group)
 317     {
 318       /* Find the end of the digit string and check its grouping.  */
 319       end = s;
 320       for (c = *end; c != L_('\0'); c = *++end)
 321         if ((wchar_t) c != thousands
 322             && ((wchar_t) c < L_('0') || (wchar_t) c > L_('9'))
 323             && (!ISALPHA (c) || (int) (TOUPPER (c) - L_('A') + 10) >= base))
 324           break;
 325       if (*s == thousands)
 326         end = s;
 327       else
 328         end = correctly_grouped_prefix (s, end, thousands, grouping);
 329     }
 330   else
 331 #endif
 332     end = NULL;
 333
 334   cutoff = STRTOL_ULONG_MAX / (unsigned LONG int) base;
 335   cutlim = STRTOL_ULONG_MAX % (unsigned LONG int) base;
 336
 337   overflow = 0;
 338   i = 0;
 339   for (c = *s; c != L_('\0'); c = *++s)
 340     {
 341       if (s == end)
 342         break;
 343       if (c >= L_('0') && c <= L_('9'))
 344         c -= L_('0');
 345       else if (ISALPHA (c))
 346         c = TOUPPER (c) - L_('A') + 10;
 347       else
 348         break;
 349       if ((int) c >= base)
 350         break;
 351       /* Check for overflow.  */
 352       if (i > cutoff || (i == cutoff && c > cutlim))
 353         overflow = 1;
 354       else
 355         {
 356           i *= (unsigned LONG int) base;
 357           i += c;
 358         }
 359     }
 360
 361   /* Check if anything actually happened.  */
 362   if (s == save)
 363     goto noconv;
 364
 365   /* Store in ENDPTR the address of one character
 366      past the last character we converted.  */
 367   if (endptr != NULL)
 368     *endptr = (STRING_TYPE *) s;
 369
 370 #if !UNSIGNED
 371   /* Check for a value that is within the range of
 372      'unsigned LONG int', but outside the range of 'LONG int'.  */
 373   if (overflow == 0
 374       && i > (negative
 375               ? -((unsigned LONG int) (STRTOL_LONG_MIN + 1)) + 1
 376               : (unsigned LONG int) STRTOL_LONG_MAX))
 377     overflow = 1;
 378 #endif
 379
 380   if (overflow)
 381     {
 382       __set_errno (ERANGE);
 383 #if UNSIGNED
 384       return STRTOL_ULONG_MAX;
 385 #else
 386       return negative ? STRTOL_LONG_MIN : STRTOL_LONG_MAX;
 387 #endif
 388     }
 389
 390   /* Return the result of the appropriate sign.  */
 391   return negative ? -i : i;
 392
 393 noconv:
 394   /* We must handle a special case here: the base is 0 or 16 and the
 395      first two characters are '0' and 'x', but the rest are no
 396      hexadecimal digits.  This is no error case.  We return 0 and
 397      ENDPTR points to the 'x'.  */
 398   if (endptr != NULL)
 399     {
 400       if (save - nptr >= 2 && TOUPPER (save[-1]) == L_('X')
 401           && save[-2] == L_('0'))
 402         *endptr = (STRING_TYPE *) &save[-1];
 403       else
 404         /*  There was no number to convert.  */
 405         *endptr = (STRING_TYPE *) nptr;
 406     }
 407
 408   return 0L;
 409 }
 410 \f
 411 /* External user entry point.  */
 412
 413
 414 INT
 415 #ifdef weak_function
 416 weak_function
 417 #endif
 418 strtol (const STRING_TYPE *nptr, STRING_TYPE **endptr,
 419         int base LOCALE_PARAM_PROTO)
 420 {
 421   return INTERNAL (strtol) (nptr, endptr, base, 0 LOCALE_PARAM);
 422 }