contrib/diffutils-2.8/lib/exclude.c

   1 /* exclude.c -- exclude file names
   2
   3    Copyright (C) 1992, 1993, 1994, 1997, 1999, 2000, 2001, 2002, 2003 Free
   4    Software 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 2, or (at your option)
   9    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; see the file COPYING.
  18    If not, write to the Free Software Foundation,
  19    59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  20
  21 /* Written by Paul Eggert <eggert@twinsun.com>  */
  22
  23 #if HAVE_CONFIG_H
  24 # include <config.h>
  25 #endif
  26
  27 #include <stdbool.h>
  28
  29 #include <ctype.h>
  30 #include <errno.h>
  31 #ifndef errno
  32 extern int errno;
  33 #endif
  34 #include <stddef.h>
  35 #include <stdio.h>
  36 #include <stdlib.h>
  37 #include <string.h>
  38
  39 #include "exclude.h"
  40 #include "fnmatch.h"
  41 #include "unlocked-io.h"
  42 #include "xalloc.h"
  43
  44 #if STDC_HEADERS || (! defined isascii && ! HAVE_ISASCII)
  45 # define IN_CTYPE_DOMAIN(c) true
  46 #else
  47 # define IN_CTYPE_DOMAIN(c) isascii (c)
  48 #endif
  49
  50 static inline bool
  51 is_space (unsigned char c)
  52 {
  53   return IN_CTYPE_DOMAIN (c) && isspace (c);
  54 }
  55
  56 /* Verify a requirement at compile-time (unlike assert, which is runtime).  */
  57 #define verify(name, assertion) struct name { char a[(assertion) ? 1 : -1]; }
  58
  59 /* Non-GNU systems lack these options, so we don't need to check them.  */
  60 #ifndef FNM_CASEFOLD
  61 # define FNM_CASEFOLD 0
  62 #endif
  63 #ifndef FNM_LEADING_DIR
  64 # define FNM_LEADING_DIR 0
  65 #endif
  66
  67 verify (EXCLUDE_macros_do_not_collide_with_FNM_macros,
  68         (((EXCLUDE_ANCHORED | EXCLUDE_INCLUDE | EXCLUDE_WILDCARDS)
  69           & (FNM_PATHNAME | FNM_NOESCAPE | FNM_PERIOD | FNM_LEADING_DIR
  70              | FNM_CASEFOLD))
  71          == 0));
  72
  73 /* An exclude pattern-options pair.  The options are fnmatch options
  74    ORed with EXCLUDE_* options.  */
  75
  76 struct patopts
  77   {
  78     char const *pattern;
  79     int options;
  80   };
  81
  82 /* An exclude list, of pattern-options pairs.  */
  83
  84 struct exclude
  85   {
  86     struct patopts *exclude;
  87     size_t exclude_alloc;
  88     size_t exclude_count;
  89   };
  90
  91 /* Return a newly allocated and empty exclude list.  */
  92
  93 struct exclude *
  94 new_exclude (void)
  95 {
  96   return xzalloc (sizeof *new_exclude ());
  97 }
  98
  99 /* Free the storage associated with an exclude list.  */
 100
 101 void
 102 free_exclude (struct exclude *ex)
 103 {
 104   free (ex->exclude);
 105   free (ex);
 106 }
 107
 108 /* Return zero if PATTERN matches F, obeying OPTIONS, except that
 109    (unlike fnmatch) wildcards are disabled in PATTERN.  */
 110
 111 static int
 112 fnmatch_no_wildcards (char const *pattern, char const *f, int options)
 113 {
 114   if (! (options & FNM_LEADING_DIR))
 115     return ((options & FNM_CASEFOLD)
 116             ? strcasecmp (pattern, f)
 117             : strcmp (pattern, f));
 118   else
 119     {
 120       size_t patlen = strlen (pattern);
 121       int r = ((options & FNM_CASEFOLD)
 122                 ? strncasecmp (pattern, f, patlen)
 123                 : strncmp (pattern, f, patlen));
 124       if (! r)
 125         {
 126           r = f[patlen];
 127           if (r == '/')
 128             r = 0;
 129         }
 130       return r;
 131     }
 132 }
 133
 134 /* Return true if EX excludes F.  */
 135
 136 bool
 137 excluded_filename (struct exclude const *ex, char const *f)
 138 {
 139   size_t exclude_count = ex->exclude_count;
 140
 141   /* If no options are given, the default is to include.  */
 142   if (exclude_count == 0)
 143     return false;
 144   else
 145     {
 146       struct patopts const *exclude = ex->exclude;
 147       size_t i;
 148
 149       /* Otherwise, the default is the opposite of the first option.  */
 150       bool excluded = !! (exclude[0].options & EXCLUDE_INCLUDE);
 151
 152       /* Scan through the options, seeing whether they change F from
 153          excluded to included or vice versa.  */
 154       for (i = 0;  i < exclude_count;  i++)
 155         {
 156           char const *pattern = exclude[i].pattern;
 157           int options = exclude[i].options;
 158           if (excluded == !! (options & EXCLUDE_INCLUDE))
 159             {
 160               int (*matcher) (char const *, char const *, int) =
 161                 (options & EXCLUDE_WILDCARDS
 162                  ? fnmatch
 163                  : fnmatch_no_wildcards);
 164               bool matched = ((*matcher) (pattern, f, options) == 0);
 165               char const *p;
 166
 167               if (! (options & EXCLUDE_ANCHORED))
 168                 for (p = f; *p && ! matched; p++)
 169                   if (*p == '/' && p[1] != '/')
 170                     matched = ((*matcher) (pattern, p + 1, options) == 0);
 171
 172               excluded ^= matched;
 173             }
 174         }
 175
 176       return excluded;
 177     }
 178 }
 179
 180 /* Append to EX the exclusion PATTERN with OPTIONS.  */
 181
 182 void
 183 add_exclude (struct exclude *ex, char const *pattern, int options)
 184 {
 185   struct patopts *patopts;
 186
 187   if (ex->exclude_count == ex->exclude_alloc)
 188     ex->exclude = x2nrealloc (ex->exclude, &ex->exclude_alloc,
 189                               sizeof *ex->exclude);
 190
 191   patopts = &ex->exclude[ex->exclude_count++];
 192   patopts->pattern = pattern;
 193   patopts->options = options;
 194 }
 195
 196 /* Use ADD_FUNC to append to EX the patterns in FILENAME, each with
 197    OPTIONS.  LINE_END terminates each pattern in the file.  If
 198    LINE_END is a space character, ignore trailing spaces and empty
 199    lines in FILE.  Return -1 on failure, 0 on success.  */
 200
 201 int
 202 add_exclude_file (void (*add_func) (struct exclude *, char const *, int),
 203                   struct exclude *ex, char const *filename, int options,
 204                   char line_end)
 205 {
 206   bool use_stdin = filename[0] == '-' && !filename[1];
 207   FILE *in;
 208   char *buf = NULL;
 209   char *p;
 210   char const *pattern;
 211   char const *lim;
 212   size_t buf_alloc = 0;
 213   size_t buf_count = 0;
 214   int c;
 215   int e = 0;
 216
 217   if (use_stdin)
 218     in = stdin;
 219   else if (! (in = fopen (filename, "r")))
 220     return -1;
 221
 222   while ((c = getc (in)) != EOF)
 223     {
 224       if (buf_count == buf_alloc)
 225         buf = x2realloc (buf, &buf_alloc);
 226       buf[buf_count++] = c;
 227     }
 228
 229   if (ferror (in))
 230     e = errno;
 231
 232   if (!use_stdin && fclose (in) != 0)
 233     e = errno;
 234
 235   buf = xrealloc (buf, buf_count + 1);
 236   buf[buf_count] = line_end;
 237   lim = buf + buf_count + ! (buf_count == 0 || buf[buf_count - 1] == line_end);
 238   pattern = buf;
 239
 240   for (p = buf; p < lim; p++)
 241     if (*p == line_end)
 242       {
 243         char *pattern_end = p;
 244
 245         if (is_space (line_end))
 246           {
 247             for (; ; pattern_end--)
 248               if (pattern_end == pattern)
 249                 goto next_pattern;
 250               else if (! is_space (pattern_end[-1]))
 251                 break;
 252           }
 253
 254         *pattern_end = '\0';
 255         (*add_func) (ex, pattern, options);
 256
 257       next_pattern:
 258         pattern = p + 1;
 259       }
 260
 261   errno = e;
 262   return e ? -1 : 0;
 263 }