grub-core/gnulib/mbswidth.c

   1 /* Determine the number of screen columns needed for a string.
   2    Copyright (C) 2000-2013 Free Software Foundation, Inc.
   3
   4    This program is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation; either version 3 of the License, or
   7    (at your option) any later version.
   8
   9    This program 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
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  16
  17 /* Written by Bruno Haible <haible@clisp.cons.org>.  */
  18
  19 #include <config.h>
  20
  21 /* Specification.  */
  22 #include "mbswidth.h"
  23
  24 /* Get MB_CUR_MAX.  */
  25 #include <stdlib.h>
  26
  27 #include <string.h>
  28
  29 /* Get isprint().  */
  30 #include <ctype.h>
  31
  32 /* Get mbstate_t, mbrtowc(), mbsinit(), wcwidth().  */
  33 #include <wchar.h>
  34
  35 /* Get iswcntrl().  */
  36 #include <wctype.h>
  37
  38 /* Get INT_MAX.  */
  39 #include <limits.h>
  40
  41 /* Returns the number of columns needed to represent the multibyte
  42    character string pointed to by STRING.  If a non-printable character
  43    occurs, and MBSW_REJECT_UNPRINTABLE is specified, -1 is returned.
  44    With flags = MBSW_REJECT_INVALID | MBSW_REJECT_UNPRINTABLE, this is
  45    the multibyte analogue of the wcswidth function.  */
  46 int
  47 mbswidth (const char *string, int flags)
  48 {
  49   return mbsnwidth (string, strlen (string), flags);
  50 }
  51
  52 /* Returns the number of columns needed to represent the multibyte
  53    character string pointed to by STRING of length NBYTES.  If a
  54    non-printable character occurs, and MBSW_REJECT_UNPRINTABLE is
  55    specified, -1 is returned.  */
  56 int
  57 mbsnwidth (const char *string, size_t nbytes, int flags)
  58 {
  59   const char *p = string;
  60   const char *plimit = p + nbytes;
  61   int width;
  62
  63   width = 0;
  64   if (MB_CUR_MAX > 1)
  65     {
  66       while (p < plimit)
  67         switch (*p)
  68           {
  69             case ' ': case '!': case '"': case '#': case '%':
  70             case '&': case '\'': case '(': case ')': case '*':
  71             case '+': case ',': case '-': case '.': case '/':
  72             case '0': case '1': case '2': case '3': case '4':
  73             case '5': case '6': case '7': case '8': case '9':
  74             case ':': case ';': case '<': case '=': case '>':
  75             case '?':
  76             case 'A': case 'B': case 'C': case 'D': case 'E':
  77             case 'F': case 'G': case 'H': case 'I': case 'J':
  78             case 'K': case 'L': case 'M': case 'N': case 'O':
  79             case 'P': case 'Q': case 'R': case 'S': case 'T':
  80             case 'U': case 'V': case 'W': case 'X': case 'Y':
  81             case 'Z':
  82             case '[': case '\\': case ']': case '^': case '_':
  83             case 'a': case 'b': case 'c': case 'd': case 'e':
  84             case 'f': case 'g': case 'h': case 'i': case 'j':
  85             case 'k': case 'l': case 'm': case 'n': case 'o':
  86             case 'p': case 'q': case 'r': case 's': case 't':
  87             case 'u': case 'v': case 'w': case 'x': case 'y':
  88             case 'z': case '{': case '|': case '}': case '~':
  89               /* These characters are printable ASCII characters.  */
  90               p++;
  91               width++;
  92               break;
  93             case '\0':
  94               if (flags & MBSW_STOP_AT_NUL)
  95                 return width;
  96             default:
  97               /* If we have a multibyte sequence, scan it up to its end.  */
  98               {
  99                 mbstate_t mbstate;
 100                 memset (&mbstate, 0, sizeof mbstate);
 101                 do
 102                   {
 103                     wchar_t wc;
 104                     size_t bytes;
 105                     int w;
 106
 107                     bytes = mbrtowc (&wc, p, plimit - p, &mbstate);
 108
 109                     if (bytes == (size_t) -1)
 110                       /* An invalid multibyte sequence was encountered.  */
 111                       {
 112                         if (!(flags & MBSW_REJECT_INVALID))
 113                           {
 114                             p++;
 115                             width++;
 116                             break;
 117                           }
 118                         else
 119                           return -1;
 120                       }
 121
 122                     if (bytes == (size_t) -2)
 123                       /* An incomplete multibyte character at the end.  */
 124                       {
 125                         if (!(flags & MBSW_REJECT_INVALID))
 126                           {
 127                             p = plimit;
 128                             width++;
 129                             break;
 130                           }
 131                         else
 132                           return -1;
 133                       }
 134
 135                     if (bytes == 0)
 136                       /* A null wide character was encountered.  */
 137                       bytes = 1;
 138
 139                     w = wcwidth (wc);
 140                     if (w >= 0)
 141                       /* A printable multibyte character.  */
 142                       {
 143                         if (w > INT_MAX - width)
 144                           goto overflow;
 145                         width += w;
 146                       }
 147                     else
 148                       /* An unprintable multibyte character.  */
 149                       if (!(flags & MBSW_REJECT_UNPRINTABLE))
 150                         {
 151                           if (!iswcntrl (wc))
 152                             {
 153                               if (width == INT_MAX)
 154                                 goto overflow;
 155                               width++;
 156                             }
 157                         }
 158                       else
 159                         return -1;
 160
 161                     p += bytes;
 162                   }
 163                 while (! mbsinit (&mbstate));
 164               }
 165               break;
 166           }
 167       return width;
 168     }
 169
 170   while (p < plimit)
 171     {
 172       unsigned char c = (unsigned char) *p++;
 173
 174       if (c == 0 && (flags & MBSW_STOP_AT_NUL))
 175         return width;
 176
 177       if (isprint (c))
 178         {
 179           if (width == INT_MAX)
 180             goto overflow;
 181           width++;
 182         }
 183       else if (!(flags & MBSW_REJECT_UNPRINTABLE))
 184         {
 185           if (!iscntrl (c))
 186             {
 187               if (width == INT_MAX)
 188                 goto overflow;
 189               width++;
 190             }
 191         }
 192       else
 193         return -1;
 194     }
 195   return width;
 196
 197  overflow:
 198   return INT_MAX;
 199 }