1 /* Low-level file-handling.
2 Copyright (C) 2012-2021 Free Software Foundation, Inc.
3
4 This file is part of GDB.
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 3 of the License, or
9 (at your option) 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. If not, see <http://www.gnu.org/licenses/>. */
18
19 #ifndef COMMON_FILESTUFF_H
20 #define COMMON_FILESTUFF_H
21
22 #include <dirent.h>
23 #include <fcntl.h>
24
25 /* Note all the file descriptors which are open when this is called.
26 These file descriptors will not be closed by close_most_fds. */
27
28 extern void notice_open_fds (void);
29
30 /* Mark a file descriptor as inheritable across an exec. */
31
32 extern void mark_fd_no_cloexec (int fd);
33
34 /* Mark a file descriptor as no longer being inheritable across an
35 exec. This is only meaningful when FD was previously passed to
36 mark_fd_no_cloexec. */
37
38 extern void unmark_fd_no_cloexec (int fd);
39
40 /* Close all open file descriptors other than those marked by
41 'notice_open_fds', and stdin, stdout, and stderr. Errors that
42 occur while closing are ignored. */
43
44 extern void close_most_fds (void);
45
46 /* Like 'open', but ensures that the returned file descriptor has the
47 close-on-exec flag set. */
48
49 extern int gdb_open_cloexec (const char *filename, int flags,
50 /* mode_t */ unsigned long mode);
51
52 /* Like mkstemp, but ensures that the file descriptor is
53 close-on-exec. */
54
55 static inline int
56 gdb_mkostemp_cloexec (char *name_template, int flags = 0)
57 {
58 /* gnulib provides a mkostemp replacement if needed. */
59 return mkostemp (name_template, flags | O_CLOEXEC);
60 }
61
62 /* Convenience wrapper for the above, which takes the filename as an
63 std::string. */
64
65 static inline int
gdb_open_cloexec(const std::string & filename,int flags,unsigned long mode)66 gdb_open_cloexec (const std::string &filename, int flags,
67 /* mode_t */ unsigned long mode)
68 {
69 return gdb_open_cloexec (filename.c_str (), flags, mode);
70 }
71
72 struct gdb_file_deleter
73 {
operatorgdb_file_deleter74 void operator() (FILE *file) const
75 {
76 fclose (file);
77 }
78 };
79
80 /* A unique pointer to a FILE. */
81
82 typedef std::unique_ptr<FILE, gdb_file_deleter> gdb_file_up;
83
84 /* Like 'fopen', but ensures that the returned file descriptor has the
85 close-on-exec flag set. */
86
87 extern gdb_file_up gdb_fopen_cloexec (const char *filename,
88 const char *opentype);
89
90 /* Convenience wrapper for the above, which takes the filename as an
91 std::string. */
92
93 static inline gdb_file_up
gdb_fopen_cloexec(const std::string & filename,const char * opentype)94 gdb_fopen_cloexec (const std::string &filename, const char *opentype)
95 {
96 return gdb_fopen_cloexec (filename.c_str (), opentype);
97 }
98
99 /* Like 'socketpair', but ensures that the returned file descriptors
100 have the close-on-exec flag set. */
101
102 extern int gdb_socketpair_cloexec (int domain, int style, int protocol,
103 int filedes[2]);
104
105 /* Like 'socket', but ensures that the returned file descriptor has
106 the close-on-exec flag set. */
107
108 extern int gdb_socket_cloexec (int domain, int style, int protocol);
109
110 /* Like 'pipe', but ensures that the returned file descriptors have
111 the close-on-exec flag set. */
112
113 extern int gdb_pipe_cloexec (int filedes[2]);
114
115 struct gdb_dir_deleter
116 {
operatorgdb_dir_deleter117 void operator() (DIR *dir) const
118 {
119 closedir (dir);
120 }
121 };
122
123 /* A unique pointer to a DIR. */
124
125 typedef std::unique_ptr<DIR, gdb_dir_deleter> gdb_dir_up;
126
127 /* Return true if the file NAME exists and is a regular file.
128 If the result is false then *ERRNO_PTR is set to a useful value assuming
129 we're expecting a regular file. */
130 extern bool is_regular_file (const char *name, int *errno_ptr);
131
132
133 /* A cheap (as in low-quality) recursive mkdir. Try to create all the
134 parents directories up to DIR and DIR itself. Stop if we hit an
135 error along the way. There is no attempt to remove created
136 directories in case of failure.
137
138 Returns false on failure and sets errno. */
139
140 extern bool mkdir_recursive (const char *dir);
141
142 #endif /* COMMON_FILESTUFF_H */
143