contrib/diffutils/lib/xstrtol.c

   1 /* A more useful interface to strtol.
   2
   3    Copyright (C) 1995-1996, 1998-2001, 2003-2007, 2009-2013 Free Software
   4    Foundation, Inc.
   5
   6    This program is free software: you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any 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, see <http://www.gnu.org/licenses/>.  */
  18
  19 /* Written by Jim Meyering. */
  20
  21 #ifndef __strtol
  22 # define __strtol strtol
  23 # define __strtol_t long int
  24 # define __xstrtol xstrtol
  25 # define STRTOL_T_MINIMUM LONG_MIN
  26 # define STRTOL_T_MAXIMUM LONG_MAX
  27 #endif
  28
  29 #include <config.h>
  30
  31 #include "xstrtol.h"
  32
  33 /* Some pre-ANSI implementations (e.g. SunOS 4)
  34    need stderr defined if assertion checking is enabled.  */
  35 #include <stdio.h>
  36
  37 #include <assert.h>
  38 #include <ctype.h>
  39 #include <errno.h>
  40 #include <limits.h>
  41 #include <stdlib.h>
  42 #include <string.h>
  43
  44 #include "intprops.h"
  45
  46 /* xstrtoll.c and xstrtoull.c, which include this file, require that
  47    ULLONG_MAX, LLONG_MAX, LLONG_MIN are defined, but <limits.h> does not
  48    define them on all platforms.  */
  49 #ifndef ULLONG_MAX
  50 # define ULLONG_MAX TYPE_MAXIMUM (unsigned long long)
  51 #endif
  52 #ifndef LLONG_MAX
  53 # define LLONG_MAX TYPE_MAXIMUM (long long int)
  54 #endif
  55 #ifndef LLONG_MIN
  56 # define LLONG_MIN TYPE_MINIMUM (long long int)
  57 #endif
  58
  59 static strtol_error
  60 bkm_scale (__strtol_t *x, int scale_factor)
  61 {
  62   if (TYPE_SIGNED (__strtol_t) && *x < STRTOL_T_MINIMUM / scale_factor)
  63     {
  64       *x = STRTOL_T_MINIMUM;
  65       return LONGINT_OVERFLOW;
  66     }
  67   if (STRTOL_T_MAXIMUM / scale_factor < *x)
  68     {
  69       *x = STRTOL_T_MAXIMUM;
  70       return LONGINT_OVERFLOW;
  71     }
  72   *x *= scale_factor;
  73   return LONGINT_OK;
  74 }
  75
  76 static strtol_error
  77 bkm_scale_by_power (__strtol_t *x, int base, int power)
  78 {
  79   strtol_error err = LONGINT_OK;
  80   while (power--)
  81     err |= bkm_scale (x, base);
  82   return err;
  83 }
  84
  85 /* FIXME: comment.  */
  86
  87 strtol_error
  88 __xstrtol (const char *s, char **ptr, int strtol_base,
  89            __strtol_t *val, const char *valid_suffixes)
  90 {
  91   char *t_ptr;
  92   char **p;
  93   __strtol_t tmp;
  94   strtol_error err = LONGINT_OK;
  95
  96   assert (0 <= strtol_base && strtol_base <= 36);
  97
  98   p = (ptr ? ptr : &t_ptr);
  99
 100   if (! TYPE_SIGNED (__strtol_t))
 101     {
 102       const char *q = s;
 103       unsigned char ch = *q;
 104       while (isspace (ch))
 105         ch = *++q;
 106       if (ch == '-')
 107         return LONGINT_INVALID;
 108     }
 109
 110   errno = 0;
 111   tmp = __strtol (s, p, strtol_base);
 112
 113   if (*p == s)
 114     {
 115       /* If there is no number but there is a valid suffix, assume the
 116          number is 1.  The string is invalid otherwise.  */
 117       if (valid_suffixes && **p && strchr (valid_suffixes, **p))
 118         tmp = 1;
 119       else
 120         return LONGINT_INVALID;
 121     }
 122   else if (errno != 0)
 123     {
 124       if (errno != ERANGE)
 125         return LONGINT_INVALID;
 126       err = LONGINT_OVERFLOW;
 127     }
 128
 129   /* Let valid_suffixes == NULL mean "allow any suffix".  */
 130   /* FIXME: update all callers except the ones that allow suffixes
 131      after the number, changing last parameter NULL to "".  */
 132   if (!valid_suffixes)
 133     {
 134       *val = tmp;
 135       return err;
 136     }
 137
 138   if (**p != '\0')
 139     {
 140       int base = 1024;
 141       int suffixes = 1;
 142       strtol_error overflow;
 143
 144       if (!strchr (valid_suffixes, **p))
 145         {
 146           *val = tmp;
 147           return err | LONGINT_INVALID_SUFFIX_CHAR;
 148         }
 149
 150       if (strchr (valid_suffixes, '0'))
 151         {
 152           /* The "valid suffix" '0' is a special flag meaning that
 153              an optional second suffix is allowed, which can change
 154              the base.  A suffix "B" (e.g. "100MB") stands for a power
 155              of 1000, whereas a suffix "iB" (e.g. "100MiB") stands for
 156              a power of 1024.  If no suffix (e.g. "100M"), assume
 157              power-of-1024.  */
 158
 159           switch (p[0][1])
 160             {
 161             case 'i':
 162               if (p[0][2] == 'B')
 163                 suffixes += 2;
 164               break;
 165
 166             case 'B':
 167             case 'D': /* 'D' is obsolescent */
 168               base = 1000;
 169               suffixes++;
 170               break;
 171             }
 172         }
 173
 174       switch (**p)
 175         {
 176         case 'b':
 177           overflow = bkm_scale (&tmp, 512);
 178           break;
 179
 180         case 'B':
 181           overflow = bkm_scale (&tmp, 1024);
 182           break;
 183
 184         case 'c':
 185           overflow = 0;
 186           break;
 187
 188         case 'E': /* exa or exbi */
 189           overflow = bkm_scale_by_power (&tmp, base, 6);
 190           break;
 191
 192         case 'G': /* giga or gibi */
 193         case 'g': /* 'g' is undocumented; for compatibility only */
 194           overflow = bkm_scale_by_power (&tmp, base, 3);
 195           break;
 196
 197         case 'k': /* kilo */
 198         case 'K': /* kibi */
 199           overflow = bkm_scale_by_power (&tmp, base, 1);
 200           break;
 201
 202         case 'M': /* mega or mebi */
 203         case 'm': /* 'm' is undocumented; for compatibility only */
 204           overflow = bkm_scale_by_power (&tmp, base, 2);
 205           break;
 206
 207         case 'P': /* peta or pebi */
 208           overflow = bkm_scale_by_power (&tmp, base, 5);
 209           break;
 210
 211         case 'T': /* tera or tebi */
 212         case 't': /* 't' is undocumented; for compatibility only */
 213           overflow = bkm_scale_by_power (&tmp, base, 4);
 214           break;
 215
 216         case 'w':
 217           overflow = bkm_scale (&tmp, 2);
 218           break;
 219
 220         case 'Y': /* yotta or 2**80 */
 221           overflow = bkm_scale_by_power (&tmp, base, 8);
 222           break;
 223
 224         case 'Z': /* zetta or 2**70 */
 225           overflow = bkm_scale_by_power (&tmp, base, 7);
 226           break;
 227
 228         default:
 229           *val = tmp;
 230           return err | LONGINT_INVALID_SUFFIX_CHAR;
 231         }
 232
 233       err |= overflow;
 234       *p += suffixes;
 235       if (**p)
 236         err |= LONGINT_INVALID_SUFFIX_CHAR;
 237     }
 238
 239   *val = tmp;
 240   return err;
 241 }