xref: /freebsd/contrib/diff/lib/exclude.c (revision 8f8790cdf48a0190fca8ba4f55180136cd1ccca7)
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