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
  35 #ifdef HAVE_LIMITS_H
  36 # include <limits.h>
  37 #endif
  38
  39 #ifdef STDC_HEADERS
  40 # include <stddef.h>
  41 # include <stdlib.h>
  42 #else
  43 # ifndef NULL
  44 #  define NULL 0
  45 # endif
  46 #endif
  47
  48 #ifdef USE_NUMBER_GROUPING
  49 # include "../locale/localeinfo.h"
  50 #endif
  51
  52 /* Nonzero if we are defining `strtoul' or `strtouq', operating on
  53    unsigned integers.  */
  54 #ifndef UNSIGNED
  55 # define UNSIGNED 0
  56 # define INT LONG int
  57 #else
  58 # define INT unsigned LONG int
  59 #endif
  60
  61 /* Determine the name.  */
  62 #if UNSIGNED
  63 # ifdef USE_WIDE_CHAR
  64 #  ifdef QUAD
  65 #   define strtol wcstouq
  66 #  else
  67 #   define strtol wcstoul
  68 #  endif
  69 # else
  70 #  ifdef QUAD
  71 #   define strtol strtouq
  72 #  else
  73 #   define strtol strtoul
  74 #  endif
  75 # endif
  76 #else
  77 # ifdef USE_WIDE_CHAR
  78 #  ifdef QUAD
  79 #   define strtol wcstoq
  80 #  else
  81 #   define strtol wcstol
  82 #  endif
  83 # else
  84 #  ifdef QUAD
  85 #   define strtol strtoq
  86 #  endif
  87 # endif
  88 #endif
  89
  90 /* If QUAD is defined, we are defining `strtoq' or `strtouq',
  91    operating on `long long int's.  */
  92 #ifdef QUAD
  93 # define LONG long long
  94 # undef LONG_MIN
  95 # define LONG_MIN LONG_LONG_MIN
  96 # undef LONG_MAX
  97 # define LONG_MAX LONG_LONG_MAX
  98 # undef ULONG_MAX
  99 # define ULONG_MAX ULONG_LONG_MAX
 100 # if __GNUC__ == 2 && __GNUC_MINOR__ < 7
 101    /* Work around gcc bug with using this constant.  */
 102    static const unsigned long long int maxquad = ULONG_LONG_MAX;
 103 #  undef ULONG_MAX
 104 #  define ULONG_MAX maxquad
 105 # endif
 106 #else
 107 # define LONG long
 108 #endif
 109
 110 #ifdef USE_WIDE_CHAR
 111 # include <wchar.h>
 112 # include <wctype.h>
 113 # define L_(ch) L##ch
 114 # define UCHAR_TYPE wint_t
 115 # define STRING_TYPE wchar_t
 116 # define ISSPACE(ch) iswspace (ch)
 117 # define ISALPHA(ch) iswalpha (ch)
 118 # define TOUPPER(ch) towupper (ch)
 119 #else
 120 # define L_(ch) ch
 121 # define UCHAR_TYPE unsigned char
 122 # define STRING_TYPE char
 123 # define ISSPACE(ch) isspace (ch)
 124 # define ISALPHA(ch) isalpha (ch)
 125 # define TOUPPER(ch) toupper (ch)
 126 #endif
 127
 128 #ifdef __STDC__
 129 # define INTERNAL(x) INTERNAL1(x)
 130 # define INTERNAL1(x) __##x##_internal
 131 #else
 132 # define INTERNAL(x) __/**/x/**/_internal
 133 #endif
 134
 135 #ifdef USE_NUMBER_GROUPING
 136 /* This file defines a function to check for correct grouping.  */
 137 # include "grouping.h"
 138 #endif
 139
 140
 141 /* Convert NPTR to an `unsigned long int' or `long int' in base BASE.
 142    If BASE is 0 the base is determined by the presence of a leading
 143    zero, indicating octal or a leading "0x" or "0X", indicating hexadecimal.
 144    If BASE is < 2 or > 36, it is reset to 10.
 145    If ENDPTR is not NULL, a pointer to the character after the last
 146    one converted is stored in *ENDPTR.  */
 147
 148 INT
 149 INTERNAL (strtol) (nptr, endptr, base, group)
 150      const STRING_TYPE *nptr;
 151      STRING_TYPE **endptr;
 152      int base;
 153      int group;
 154 {
 155   int negative;
 156   register unsigned LONG int cutoff;
 157   register unsigned int cutlim;
 158   register unsigned LONG int i;
 159   register const STRING_TYPE *s;
 160   register UCHAR_TYPE c;
 161   const STRING_TYPE *save, *end;
 162   int overflow;
 163
 164 #ifdef USE_NUMBER_GROUPING
 165   /* The thousands character of the current locale.  */
 166   wchar_t thousands;
 167   /* The numeric grouping specification of the current locale,
 168      in the format described in <locale.h>.  */
 169   const char *grouping;
 170
 171   if (group)
 172     {
 173       grouping = _NL_CURRENT (LC_NUMERIC, GROUPING);
 174       if (*grouping <= 0 || *grouping == CHAR_MAX)
 175         grouping = NULL;
 176       else
 177         {
 178           /* Figure out the thousands separator character.  */
 179           if (mbtowc (&thousands, _NL_CURRENT (LC_NUMERIC, THOUSANDS_SEP),
 180                       strlen (_NL_CURRENT (LC_NUMERIC, THOUSANDS_SEP))) <= 0)
 181             thousands = (wchar_t) *_NL_CURRENT (LC_NUMERIC, THOUSANDS_SEP);
 182           if (thousands == L'\0')
 183             grouping = NULL;
 184         }
 185     }
 186   else
 187     grouping = NULL;
 188 #endif
 189
 190   if (base < 0 || base == 1 || base > 36)
 191     base = 10;
 192
 193   save = s = nptr;
 194
 195   /* Skip white space.  */
 196   while (ISSPACE (*s))
 197     ++s;
 198   if (*s == L_('\0'))
 199     goto noconv;
 200
 201   /* Check for a sign.  */
 202   if (*s == L_('-'))
 203     {
 204       negative = 1;
 205       ++s;
 206     }
 207   else if (*s == L_('+'))
 208     {
 209       negative = 0;
 210       ++s;
 211     }
 212   else
 213     negative = 0;
 214
 215   if (base == 16 && s[0] == L_('0') && TOUPPER (s[1]) == L_('X'))
 216     s += 2;
 217
 218   /* If BASE is zero, figure it out ourselves.  */
 219   if (base == 0)
 220     if (*s == L_('0'))
 221       {
 222         if (TOUPPER (s[1]) == L_('X'))
 223           {
 224             s += 2;
 225             base = 16;
 226           }
 227         else
 228           base = 8;
 229       }
 230     else
 231       base = 10;
 232
 233   /* Save the pointer so we can check later if anything happened.  */
 234   save = s;
 235
 236 #ifdef USE_NUMBER_GROUPING
 237   if (group)
 238     {
 239       /* Find the end of the digit string and check its grouping.  */
 240       end = s;
 241       for (c = *end; c != L_('\0'); c = *++end)
 242         if (c != thousands && (c < L_('0') || c > L_('9'))
 243             && (!ISALPHA (c) || TOUPPER (c) - L_('A') + 10 >= base))
 244           break;
 245       if (*s == thousands)
 246         end = s;
 247       else
 248         end = correctly_grouped_prefix (s, end, thousands, grouping);
 249     }
 250   else
 251 #endif
 252     end = NULL;
 253
 254   cutoff = ULONG_MAX / (unsigned LONG int) base;
 255   cutlim = ULONG_MAX % (unsigned LONG int) base;
 256
 257   overflow = 0;
 258   i = 0;
 259   for (c = *s; c != L_('\0'); c = *++s)
 260     {
 261       if (s == end)
 262         break;
 263       if (c >= L_('0') && c <= L_('9'))
 264         c -= L_('0');
 265       else if (ISALPHA (c))
 266         c = TOUPPER (c) - L_('A') + 10;
 267       else
 268         break;
 269       if (c >= base)
 270         break;
 271       /* Check for overflow.  */
 272       if (i > cutoff || (i == cutoff && c > cutlim))
 273         overflow = 1;
 274       else
 275         {
 276           i *= (unsigned LONG int) base;
 277           i += c;
 278         }
 279     }
 280
 281   /* Check if anything actually happened.  */
 282   if (s == save)
 283     goto noconv;
 284
 285   /* Store in ENDPTR the address of one character
 286      past the last character we converted.  */
 287   if (endptr != NULL)
 288     *endptr = (STRING_TYPE *) s;
 289
 290 #if !UNSIGNED
 291   /* Check for a value that is within the range of
 292      `unsigned LONG int', but outside the range of `LONG int'.  */
 293   if (i > (negative ?
 294            -(unsigned LONG int) LONG_MIN : (unsigned LONG int) LONG_MAX))
 295     overflow = 1;
 296 #endif
 297
 298   if (overflow)
 299     {
 300       errno = ERANGE;
 301 #if UNSIGNED
 302       return ULONG_MAX;
 303 #else
 304       return negative ? LONG_MIN : LONG_MAX;
 305 #endif
 306     }
 307
 308   /* Return the result of the appropriate sign.  */
 309   return (negative ? -i : i);
 310
 311 noconv:
 312   /* We must handle a special case here: the base is 0 or 16 and the
 313      first two characters and '0' and 'x', but the rest are no
 314      hexadecimal digits.  This is no error case.  We return 0 and
 315      ENDPTR points to the `x`.  */
 316   if (endptr != NULL)
 317     if (save - nptr >= 2 && TOUPPER (save[-1]) == L_('X')
 318         && save[-2] == L_('0'))
 319       *endptr = (STRING_TYPE *) &save[-1];
 320     else
 321       /*  There was no number to convert.  */
 322       *endptr = (STRING_TYPE *) nptr;
 323
 324   return 0L;
 325 }
 326 \f
 327 /* External user entry point.  */
 328
 329 INT
 330 strtol (nptr, endptr, base)
 331      const STRING_TYPE *nptr;
 332      STRING_TYPE **endptr;
 333      int base;
 334 {
 335   return INTERNAL (strtol) (nptr, endptr, base, 0);
 336 }
 337
 338 #ifdef weak_symbol
 339 /* We need this indirection when `strtol' is defined as a macro
 340    for one of the other names.  */
 341 #define weak1(x) weak_symbol(x)
 342 weak1 (strtol)
 343 #endif