1 /* Perform tilde expansion on paths for GDB and gdbserver.
2
3 Copyright (C) 2017-2021 Free Software Foundation, Inc.
4
5 This file is part of GDB.
6
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
11
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
19
20 #include "common-defs.h"
21 #include <algorithm>
22 #include "filenames.h"
23 #include "gdb_tilde_expand.h"
24 #include <glob.h>
25
26 /* RAII-style class wrapping "glob". */
27
28 class gdb_glob
29 {
30 public:
31 /* Construct a "gdb_glob" object by calling "glob" with the provided
32 parameters. This function can throw if "glob" fails. */
gdb_glob(const char * pattern,int flags,int (* errfunc)(const char * epath,int eerrno))33 gdb_glob (const char *pattern, int flags,
34 int (*errfunc) (const char *epath, int eerrno))
35 {
36 int ret = glob (pattern, flags, errfunc, &m_glob);
37
38 if (ret != 0)
39 {
40 if (ret == GLOB_NOMATCH)
41 error (_("Could not find a match for '%s'."), pattern);
42 else
43 error (_("glob could not process pattern '%s'."),
44 pattern);
45 }
46 }
47
48 /* Destroy the object and free M_GLOB. */
~gdb_glob()49 ~gdb_glob ()
50 {
51 globfree (&m_glob);
52 }
53
54 /* Return the GL_PATHC component of M_GLOB. */
pathc() const55 int pathc () const
56 {
57 return m_glob.gl_pathc;
58 }
59
60 /* Return the GL_PATHV component of M_GLOB. */
pathv() const61 char **pathv () const
62 {
63 return m_glob.gl_pathv;
64 }
65
66 private:
67 /* The actual glob object we're dealing with. */
68 glob_t m_glob;
69 };
70
71 /* See gdbsupport/gdb_tilde_expand.h. */
72
73 std::string
gdb_tilde_expand(const char * dir)74 gdb_tilde_expand (const char *dir)
75 {
76 if (dir[0] != '~')
77 return std::string (dir);
78
79 /* This function uses glob in order to expand the ~. However, this function
80 will fail to expand if the actual dir we are looking for does not exist.
81 Given "~/does/not/exist", glob will fail.
82
83 In order to avoid such limitation, we only use glob to expand "~" and keep
84 "/does/not/exist" unchanged.
85
86 Similarly, to expand ~gdb/might/not/exist, we only expand "~gdb" using
87 glob and leave "/might/not/exist" unchanged. */
88 const std::string d (dir);
89
90 /* Look for the first dir separator (if any) and split d around it. */
91 const auto first_sep
92 = std::find_if (d.cbegin (), d.cend(),
93 [] (const char c) -> bool
94 {
95 return IS_DIR_SEPARATOR (c);
96 });
97 const std::string to_expand (d.cbegin (), first_sep);
98 const std::string remainder (first_sep, d.cend ());
99
100 const gdb_glob glob (to_expand.c_str (), GLOB_TILDE_CHECK, nullptr);
101
102 gdb_assert (glob.pathc () == 1);
103 return std::string (glob.pathv ()[0]) + remainder;
104 }
105
106 /* See gdbsupport/gdb_tilde_expand.h. */
107
108 gdb::unique_xmalloc_ptr<char>
gdb_tilde_expand_up(const char * dir)109 gdb_tilde_expand_up (const char *dir)
110 {
111 const std::string expanded = gdb_tilde_expand (dir);
112 return make_unique_xstrdup (expanded.c_str ());
113 }
114