1/* help detect directory cycles efficiently
2
3   Copyright (C) 2003-2004, 2006, 2009-2010 Free Software Foundation, Inc.
4
5   This program is free software: you can redistribute it and/or modify
6   it under the terms of the GNU General Public License as published by
7   the Free Software Foundation; either version 3 of the License, or
8   (at your option) any later version.
9
10   This program is distributed in the hope that it will be useful,
11   but WITHOUT ANY WARRANTY; without even the implied warranty of
12   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13   GNU General Public License for more details.
14
15   You should have received a copy of the GNU General Public License
16   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
17
18/* Written by Jim Meyering */
19
20#ifndef CYCLE_CHECK_H
21# define CYCLE_CHECK_H 1
22
23# include <stdint.h>
24# include <stdbool.h>
25# include "dev-ino.h"
26# include "same-inode.h"
27
28struct cycle_check_state
29{
30  struct dev_ino dev_ino;
31  uintmax_t chdir_counter;
32  int magic;
33};
34
35void cycle_check_init (struct cycle_check_state *state);
36bool cycle_check (struct cycle_check_state *state, struct stat const *sb);
37
38# define CYCLE_CHECK_REFLECT_CHDIR_UP(State, SB_dir, SB_subdir) \
39  do                                                            \
40    {                                                           \
41      /* You must call cycle_check at least once before using this macro.  */ \
42      if ((State)->chdir_counter == 0)                          \
43        abort ();                                               \
44      if (SAME_INODE ((State)->dev_ino, SB_subdir))             \
45        {                                                       \
46          (State)->dev_ino.st_dev = (SB_dir).st_dev;            \
47          (State)->dev_ino.st_ino = (SB_dir).st_ino;            \
48        }                                                       \
49    }                                                           \
50  while (0)
51
52#endif
53