gnu/dist/diffutils/lib/exclude.c

   1 /*      $NetBSD$        */
   2
   3 /* exclude.c -- exclude file names
   4
   5    Copyright 1992, 1993, 1994, 1997, 1999, 2000, 2001 Free Software
   6    Foundation, Inc.
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 2, or (at your option)
  11    any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program; see the file COPYING.
  20    If not, write to the Free Software Foundation,
  21    59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  22
  23 /* Written by Paul Eggert <eggert@twinsun.com>  */
  24
  25 #if HAVE_CONFIG_H
  26 # include <config.h>
  27 #endif
  28
  29 #if HAVE_STDBOOL_H
  30 # include <stdbool.h>
  31 #else
  32 typedef enum {false = 0, true = 1} bool;
  33 #endif
  34
  35 #include <errno.h>
  36 #ifndef errno
  37 extern int errno;
  38 #endif
  39 #include <stdio.h>
  40 #if HAVE_SYS_TYPES_H
  41 # include <sys/types.h>
  42 #endif
  43 #if HAVE_STDLIB_H
  44 # include <stdlib.h>
  45 #endif
  46 #if HAVE_STRING_H
  47 # include <string.h>
  48 #endif
  49 #if HAVE_STRINGS_H
  50 # include <strings.h>
  51 #endif
  52 #if HAVE_INTTYPES_H
  53 # include <inttypes.h>
  54 #else
  55 # if HAVE_STDINT_H
  56 #  include <stdint.h>
  57 # endif
  58 #endif
  59
  60 #include "exclude.h"
  61 #include "fnmatch.h"
  62 #include "unlocked-io.h"
  63 #include "xalloc.h"
  64
  65 #ifndef SIZE_MAX
  66 # define SIZE_MAX ((size_t) -1)
  67 #endif
  68
  69 /* Verify a requirement at compile-time (unlike assert, which is runtime).  */
  70 #define verify(name, assertion) struct name { char a[(assertion) ? 1 : -1]; }
  71
  72 verify (EXCLUDE_macros_do_not_collide_with_FNM_macros,
  73         (((EXCLUDE_ANCHORED | EXCLUDE_INCLUDE | EXCLUDE_WILDCARDS)
  74           & (FNM_FILE_NAME | FNM_NOESCAPE | FNM_PERIOD | FNM_LEADING_DIR
  75              | FNM_CASEFOLD))
  76          == 0));
  77
  78 /* An exclude pattern-options pair.  The options are fnmatch options
  79    ORed with EXCLUDE_* options.  */
  80
  81 struct patopts
  82   {
  83     char const *pattern;
  84     int options;
  85   };
  86
  87 /* An exclude list, of pattern-options pairs.  */
  88
  89 struct exclude
  90   {
  91     struct patopts *exclude;
  92     size_t exclude_alloc;
  93     size_t exclude_count;
  94   };
  95
  96 /* Return a newly allocated and empty exclude list.  */
  97
  98 struct exclude *
  99 new_exclude (void)
 100 {
 101   struct exclude *ex = (struct exclude *) xmalloc (sizeof *ex);
 102   ex->exclude_count = 0;
 103   ex->exclude_alloc = (1 << 6); /* This must be a power of 2.  */
 104   ex->exclude = (struct patopts *) xmalloc (ex->exclude_alloc
 105                                             * sizeof ex->exclude[0]);
 106   return ex;
 107 }
 108
 109 /* Free the storage associated with an exclude list.  */
 110
 111 void
 112 free_exclude (struct exclude *ex)
 113 {
 114   free (ex->exclude);
 115   free (ex);
 116 }
 117
 118 /* Return zero if PATTERN matches F, obeying OPTIONS, except that
 119    (unlike fnmatch) wildcards are disabled in PATTERN.  */
 120
 121 static int
 122 fnmatch_no_wildcards (char const *pattern, char const *f, int options)
 123 {
 124   if (! (options & FNM_LEADING_DIR))
 125     return ((options & FNM_CASEFOLD)
 126             ? strcasecmp (pattern, f)
 127             : strcmp (pattern, f));
 128   else
 129     {
 130       size_t patlen = strlen (pattern);
 131       int r = ((options & FNM_CASEFOLD)
 132                 ? strncasecmp (pattern, f, patlen)
 133                 : strncmp (pattern, f, patlen));
 134       if (! r)
 135         {
 136           r = f[patlen];
 137           if (r == '/')
 138             r = 0;
 139         }
 140       return r;
 141     }
 142 }
 143
 144 /* Return true if EX excludes F.  */
 145
 146 bool
 147 excluded_filename (struct exclude const *ex, char const *f)
 148 {
 149   size_t exclude_count = ex->exclude_count;
 150
 151   /* If no options are given, the default is to include.  */
 152   if (exclude_count == 0)
 153     return false;
 154   else
 155     {
 156       struct patopts const *exclude = ex->exclude;
 157       size_t i;
 158
 159       /* Otherwise, the default is the opposite of the first option.  */
 160       bool excluded = !! (exclude[0].options & EXCLUDE_INCLUDE);
 161
 162       /* Scan through the options, seeing whether they change F from
 163          excluded to included or vice versa.  */
 164       for (i = 0;  i < exclude_count;  i++)
 165         {
 166           char const *pattern = exclude[i].pattern;
 167           int options = exclude[i].options;
 168           if (excluded == !! (options & EXCLUDE_INCLUDE))
 169             {
 170               int (*matcher) PARAMS ((char const *, char const *, int)) =
 171                 (options & EXCLUDE_WILDCARDS
 172                  ? fnmatch
 173                  : fnmatch_no_wildcards);
 174               bool matched = ((*matcher) (pattern, f, options) == 0);
 175               char const *p;
 176
 177               if (! (options & EXCLUDE_ANCHORED))
 178                 for (p = f; *p && ! matched; p++)
 179                   if (*p == '/' && p[1] != '/')
 180                     matched = ((*matcher) (pattern, p + 1, options) == 0);
 181
 182               excluded ^= matched;
 183             }
 184         }
 185
 186       return excluded;
 187     }
 188 }
 189
 190 /* Append to EX the exclusion PATTERN with OPTIONS.  */
 191
 192 void
 193 add_exclude (struct exclude *ex, char const *pattern, int options)
 194 {
 195   struct patopts *patopts;
 196
 197   if (ex->exclude_alloc <= ex->exclude_count)
 198     {
 199       size_t s = 2 * ex->exclude_alloc;
 200       if (! (0 < s && s <= SIZE_MAX / sizeof ex->exclude[0]))
 201         xalloc_die ();
 202       ex->exclude_alloc = s;
 203       ex->exclude = (struct patopts *) xrealloc (ex->exclude,
 204                                                  s * sizeof ex->exclude[0]);
 205     }
 206
 207   patopts = &ex->exclude[ex->exclude_count++];
 208   patopts->pattern = pattern;
 209   patopts->options = options;
 210 }
 211
 212 /* Use ADD_FUNC to append to EX the patterns in FILENAME, each with
 213    OPTIONS.  LINE_END terminates each pattern in the file.  Return -1
 214    on failure, 0 on success.  */
 215
 216 int
 217 add_exclude_file (void (*add_func) PARAMS ((struct exclude *,
 218                                             char const *, int)),
 219                   struct exclude *ex, char const *filename, int options,
 220                   char line_end)
 221 {
 222   bool use_stdin = filename[0] == '-' && !filename[1];
 223   FILE *in;
 224   char *buf;
 225   char *p;
 226   char const *pattern;
 227   char const *lim;
 228   size_t buf_alloc = (1 << 10);  /* This must be a power of two.  */
 229   size_t buf_count = 0;
 230   int c;
 231   int e = 0;
 232
 233   if (use_stdin)
 234     in = stdin;
 235   else if (! (in = fopen (filename, "r")))
 236     return -1;
 237
 238   buf = xmalloc (buf_alloc);
 239
 240   while ((c = getc (in)) != EOF)
 241     {
 242       buf[buf_count++] = c;
 243       if (buf_count == buf_alloc)
 244         {
 245           buf_alloc *= 2;
 246           if (! buf_alloc)
 247             xalloc_die ();
 248           buf = xrealloc (buf, buf_alloc);
 249         }
 250     }
 251
 252   if (ferror (in))
 253     e = errno;
 254
 255   if (!use_stdin && fclose (in) != 0)
 256     e = errno;
 257
 258   buf = xrealloc (buf, buf_count + 1);
 259
 260   for (pattern = p = buf, lim = buf + buf_count;  p <= lim;  p++)
 261     if (p < lim ? *p == line_end : buf < p && p[-1])
 262       {
 263         *p = '\0';
 264         (*add_func) (ex, pattern, options);
 265         pattern = p + 1;
 266       }
 267
 268   errno = e;
 269   return e ? -1 : 0;
 270 }