xref: /freebsd/contrib/diff/lib/exclude.c (revision cd0d51baaa4509a1db83251a601d34404d20c990)
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 }
264