lib/exclude.c

   1 /* exclude.c -- exclude file names
   2
   3    Copyright (C) 1992, 1993, 1994, 1997, 1999, 2000, 2001, 2002 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 #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 /* Non-GNU systems lack these options, so we don't need to check them.  */
  71 #ifndef FNM_CASEFOLD
  72 # define FNM_CASEFOLD 0
  73 #endif
  74 #ifndef FNM_LEADING_DIR
  75 # define FNM_LEADING_DIR 0
  76 #endif
  77
  78 verify (EXCLUDE_macros_do_not_collide_with_FNM_macros,
  79         (((EXCLUDE_ANCHORED | EXCLUDE_INCLUDE | EXCLUDE_WILDCARDS)
  80           & (FNM_PATHNAME | FNM_NOESCAPE | FNM_PERIOD | FNM_LEADING_DIR
  81              | FNM_CASEFOLD))
  82          == 0));
  83
  84 /* An exclude pattern-options pair.  The options are fnmatch options
  85    ORed with EXCLUDE_* options.  */
  86
  87 struct patopts
  88   {
  89     char const *pattern;
  90     int options;
  91   };
  92
  93 /* An exclude list, of pattern-options pairs.  */
  94
  95 struct exclude
  96   {
  97     struct patopts *exclude;
  98     size_t exclude_alloc;
  99     size_t exclude_count;
 100   };
 101
 102 /* Return a newly allocated and empty exclude list.  */
 103
 104 struct exclude *
 105 new_exclude (void)
 106 {
 107   struct exclude *ex = (struct exclude *) xmalloc (sizeof *ex);
 108   ex->exclude_count = 0;
 109   ex->exclude_alloc = (1 << 6); /* This must be a power of 2.  */
 110   ex->exclude = (struct patopts *) xmalloc (ex->exclude_alloc
 111                                             * sizeof ex->exclude[0]);
 112   return ex;
 113 }
 114
 115 /* Free the storage associated with an exclude list.  */
 116
 117 void
 118 free_exclude (struct exclude *ex)
 119 {
 120   free (ex->exclude);
 121   free (ex);
 122 }
 123
 124 /* Return zero if PATTERN matches F, obeying OPTIONS, except that
 125    (unlike fnmatch) wildcards are disabled in PATTERN.  */
 126
 127 static int
 128 fnmatch_no_wildcards (char const *pattern, char const *f, int options)
 129 {
 130   if (! (options & FNM_LEADING_DIR))
 131     return ((options & FNM_CASEFOLD)
 132             ? strcasecmp (pattern, f)
 133             : strcmp (pattern, f));
 134   else
 135     {
 136       size_t patlen = strlen (pattern);
 137       int r = ((options & FNM_CASEFOLD)
 138                 ? strncasecmp (pattern, f, patlen)
 139                 : strncmp (pattern, f, patlen));
 140       if (! r)
 141         {
 142           r = f[patlen];
 143           if (r == '/')
 144             r = 0;
 145         }
 146       return r;
 147     }
 148 }
 149
 150 /* Return true if EX excludes F.  */
 151
 152 bool
 153 excluded_filename (struct exclude const *ex, char const *f)
 154 {
 155   size_t exclude_count = ex->exclude_count;
 156
 157   /* If no options are given, the default is to include.  */
 158   if (exclude_count == 0)
 159     return false;
 160   else
 161     {
 162       struct patopts const *exclude = ex->exclude;
 163       size_t i;
 164
 165       /* Otherwise, the default is the opposite of the first option.  */
 166       bool excluded = !! (exclude[0].options & EXCLUDE_INCLUDE);
 167
 168       /* Scan through the options, seeing whether they change F from
 169          excluded to included or vice versa.  */
 170       for (i = 0;  i < exclude_count;  i++)
 171         {
 172           char const *pattern = exclude[i].pattern;
 173           int options = exclude[i].options;
 174           if (excluded == !! (options & EXCLUDE_INCLUDE))
 175             {
 176               int (*matcher) PARAMS ((char const *, char const *, int)) =
 177                 (options & EXCLUDE_WILDCARDS
 178                  ? fnmatch
 179                  : fnmatch_no_wildcards);
 180               bool matched = ((*matcher) (pattern, f, options) == 0);
 181               char const *p;
 182
 183               if (! (options & EXCLUDE_ANCHORED))
 184                 for (p = f; *p && ! matched; p++)
 185                   if (*p == '/' && p[1] != '/')
 186                     matched = ((*matcher) (pattern, p + 1, options) == 0);
 187
 188               excluded ^= matched;
 189             }
 190         }
 191
 192       return excluded;
 193     }
 194 }
 195
 196 /* Append to EX the exclusion PATTERN with OPTIONS.  */
 197
 198 void
 199 add_exclude (struct exclude *ex, char const *pattern, int options)
 200 {
 201   struct patopts *patopts;
 202
 203   if (ex->exclude_alloc <= ex->exclude_count)
 204     {
 205       size_t s = 2 * ex->exclude_alloc;
 206       if (! (0 < s && s <= SIZE_MAX / sizeof ex->exclude[0]))
 207         xalloc_die ();
 208       ex->exclude_alloc = s;
 209       ex->exclude = (struct patopts *) xrealloc (ex->exclude,
 210                                                  s * sizeof ex->exclude[0]);
 211     }
 212
 213   patopts = &ex->exclude[ex->exclude_count++];
 214   patopts->pattern = pattern;
 215   patopts->options = options;
 216 }
 217
 218 /* Use ADD_FUNC to append to EX the patterns in FILENAME, each with
 219    OPTIONS.  LINE_END terminates each pattern in the file.  Return -1
 220    on failure, 0 on success.  */
 221
 222 int
 223 add_exclude_file (void (*add_func) PARAMS ((struct exclude *,
 224                                             char const *, int)),
 225                   struct exclude *ex, char const *filename, int options,
 226                   char line_end)
 227 {
 228   bool use_stdin = filename[0] == '-' && !filename[1];
 229   FILE *in;
 230   char *buf;
 231   char *p;
 232   char const *pattern;
 233   char const *lim;
 234   size_t buf_alloc = (1 << 10);  /* This must be a power of two.  */
 235   size_t buf_count = 0;
 236   int c;
 237   int e = 0;
 238
 239   if (use_stdin)
 240     in = stdin;
 241   else if (! (in = fopen (filename, "r")))
 242     return -1;
 243
 244   buf = xmalloc (buf_alloc);
 245
 246   while ((c = getc (in)) != EOF)
 247     {
 248       buf[buf_count++] = c;
 249       if (buf_count == buf_alloc)
 250         {
 251           buf_alloc *= 2;
 252           if (! buf_alloc)
 253             xalloc_die ();
 254           buf = xrealloc (buf, buf_alloc);
 255         }
 256     }
 257
 258   if (ferror (in))
 259     e = errno;
 260
 261   if (!use_stdin && fclose (in) != 0)
 262     e = errno;
 263
 264   buf = xrealloc (buf, buf_count + 1);
 265
 266   for (pattern = p = buf, lim = buf + buf_count;  p <= lim;  p++)
 267     if (p < lim ? *p == line_end : buf < p && p[-1])
 268       {
 269         *p = '\0';
 270         (*add_func) (ex, pattern, options);
 271         pattern = p + 1;
 272       }
 273
 274   errno = e;
 275   return e ? -1 : 0;
 276 }