contrib/diffutils-2.8.1/lib/exclude.c

   1 /* exclude.c -- exclude file names
   2
   3    Copyright 1992, 1993, 1994, 1997, 1999, 2000, 2001 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 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 #if HAVE_STDBOOL_H
  28 # include <stdbool.h>
  29 #else
  30 typedef enum {false = 0, true = 1} bool;
  31 #endif
  32
  33 #include <errno.h>
  34 #ifndef errno
  35 extern int errno;
  36 #endif
  37 #include <stdio.h>
  38 #if HAVE_SYS_TYPES_H
  39 # include <sys/types.h>
  40 #endif
  41 #if HAVE_STDLIB_H
  42 # include <stdlib.h>
  43 #endif
  44 #if HAVE_STRING_H
  45 # include <string.h>
  46 #endif
  47 #if HAVE_STRINGS_H
  48 # include <strings.h>
  49 #endif
  50 #if HAVE_INTTYPES_H
  51 # include <inttypes.h>
  52 #else
  53 # if HAVE_STDINT_H
  54 #  include <stdint.h>
  55 # endif
  56 #endif
  57
  58 #include "exclude.h"
  59 #include "fnmatch.h"
  60 #include "unlocked-io.h"
  61 #include "xalloc.h"
  62
  63 #ifndef SIZE_MAX
  64 # define SIZE_MAX ((size_t) -1)
  65 #endif
  66
  67 /* Verify a requirement at compile-time (unlike assert, which is runtime).  */
  68 #define verify(name, assertion) struct name { char a[(assertion) ? 1 : -1]; }
  69
  70 verify (EXCLUDE_macros_do_not_collide_with_FNM_macros,
  71         (((EXCLUDE_ANCHORED | EXCLUDE_INCLUDE | EXCLUDE_WILDCARDS)
  72           & (FNM_FILE_NAME | FNM_NOESCAPE | FNM_PERIOD | FNM_LEADING_DIR
  73              | FNM_CASEFOLD))
  74          == 0));
  75
  76 /* An exclude pattern-options pair.  The options are fnmatch options
  77    ORed with EXCLUDE_* options.  */
  78
  79 struct patopts
  80   {
  81     char const *pattern;
  82     int options;
  83   };
  84
  85 /* An exclude list, of pattern-options pairs.  */
  86
  87 struct exclude
  88   {
  89     struct patopts *exclude;
  90     size_t exclude_alloc;
  91     size_t exclude_count;
  92   };
  93
  94 /* Return a newly allocated and empty exclude list.  */
  95
  96 struct exclude *
  97 new_exclude (void)
  98 {
  99   struct exclude *ex = (struct exclude *) xmalloc (sizeof *ex);
 100   ex->exclude_count = 0;
 101   ex->exclude_alloc = (1 << 6); /* This must be a power of 2.  */
 102   ex->exclude = (struct patopts *) xmalloc (ex->exclude_alloc
 103                                             * sizeof ex->exclude[0]);
 104   return ex;
 105 }
 106
 107 /* Free the storage associated with an exclude list.  */
 108
 109 void
 110 free_exclude (struct exclude *ex)
 111 {
 112   free (ex->exclude);
 113   free (ex);
 114 }
 115
 116 /* Return zero if PATTERN matches F, obeying OPTIONS, except that
 117    (unlike fnmatch) wildcards are disabled in PATTERN.  */
 118
 119 static int
 120 fnmatch_no_wildcards (char const *pattern, char const *f, int options)
 121 {
 122   if (! (options & FNM_LEADING_DIR))
 123     return ((options & FNM_CASEFOLD)
 124             ? strcasecmp (pattern, f)
 125             : strcmp (pattern, f));
 126   else
 127     {
 128       size_t patlen = strlen (pattern);
 129       int r = ((options & FNM_CASEFOLD)
 130                 ? strncasecmp (pattern, f, patlen)
 131                 : strncmp (pattern, f, patlen));
 132       if (! r)
 133         {
 134           r = f[patlen];
 135           if (r == '/')
 136             r = 0;
 137         }
 138       return r;
 139     }
 140 }
 141
 142 /* Return true if EX excludes F.  */
 143
 144 bool
 145 excluded_filename (struct exclude const *ex, char const *f)
 146 {
 147   size_t exclude_count = ex->exclude_count;
 148
 149   /* If no options are given, the default is to include.  */
 150   if (exclude_count == 0)
 151     return false;
 152   else
 153     {
 154       struct patopts const *exclude = ex->exclude;
 155       size_t i;
 156
 157       /* Otherwise, the default is the opposite of the first option.  */
 158       bool excluded = !! (exclude[0].options & EXCLUDE_INCLUDE);
 159
 160       /* Scan through the options, seeing whether they change F from
 161          excluded to included or vice versa.  */
 162       for (i = 0;  i < exclude_count;  i++)
 163         {
 164           char const *pattern = exclude[i].pattern;
 165           int options = exclude[i].options;
 166           if (excluded == !! (options & EXCLUDE_INCLUDE))
 167             {
 168               int (*matcher) PARAMS ((char const *, char const *, int)) =
 169                 (options & EXCLUDE_WILDCARDS
 170                  ? fnmatch
 171                  : fnmatch_no_wildcards);
 172               bool matched = ((*matcher) (pattern, f, options) == 0);
 173               char const *p;
 174
 175               if (! (options & EXCLUDE_ANCHORED))
 176                 for (p = f; *p && ! matched; p++)
 177                   if (*p == '/' && p[1] != '/')
 178                     matched = ((*matcher) (pattern, p + 1, options) == 0);
 179
 180               excluded ^= matched;
 181             }
 182         }
 183
 184       return excluded;
 185     }
 186 }
 187
 188 /* Append to EX the exclusion PATTERN with OPTIONS.  */
 189
 190 void
 191 add_exclude (struct exclude *ex, char const *pattern, int options)
 192 {
 193   struct patopts *patopts;
 194
 195   if (ex->exclude_alloc <= ex->exclude_count)
 196     {
 197       size_t s = 2 * ex->exclude_alloc;
 198       if (! (0 < s && s <= SIZE_MAX / sizeof ex->exclude[0]))
 199         xalloc_die ();
 200       ex->exclude_alloc = s;
 201       ex->exclude = (struct patopts *) xrealloc (ex->exclude,
 202                                                  s * sizeof ex->exclude[0]);
 203     }
 204
 205   patopts = &ex->exclude[ex->exclude_count++];
 206   patopts->pattern = pattern;
 207   patopts->options = options;
 208 }
 209
 210 /* Use ADD_FUNC to append to EX the patterns in FILENAME, each with
 211    OPTIONS.  LINE_END terminates each pattern in the file.  Return -1
 212    on failure, 0 on success.  */
 213
 214 int
 215 add_exclude_file (void (*add_func) PARAMS ((struct exclude *,
 216                                             char const *, int)),
 217                   struct exclude *ex, char const *filename, int options,
 218                   char line_end)
 219 {
 220   bool use_stdin = filename[0] == '-' && !filename[1];
 221   FILE *in;
 222   char *buf;
 223   char *p;
 224   char const *pattern;
 225   char const *lim;
 226   size_t buf_alloc = (1 << 10);  /* This must be a power of two.  */
 227   size_t buf_count = 0;
 228   int c;
 229   int e = 0;
 230
 231   if (use_stdin)
 232     in = stdin;
 233   else if (! (in = fopen (filename, "r")))
 234     return -1;
 235
 236   buf = xmalloc (buf_alloc);
 237
 238   while ((c = getc (in)) != EOF)
 239     {
 240       buf[buf_count++] = c;
 241       if (buf_count == buf_alloc)
 242         {
 243           buf_alloc *= 2;
 244           if (! buf_alloc)
 245             xalloc_die ();
 246           buf = xrealloc (buf, buf_alloc);
 247         }
 248     }
 249
 250   if (ferror (in))
 251     e = errno;
 252
 253   if (!use_stdin && fclose (in) != 0)
 254     e = errno;
 255
 256   buf = xrealloc (buf, buf_count + 1);
 257
 258   for (pattern = p = buf, lim = buf + buf_count;  p <= lim;  p++)
 259     if (p < lim ? *p == line_end : buf < p && p[-1])
 260       {
 261         *p = '\0';
 262         (*add_func) (ex, pattern, options);
 263         pattern = p + 1;
 264       }
 265
 266   errno = e;
 267   return e ? -1 : 0;
 268 }