1 /* environ.c -- library for manipulating environments for GNU.
2
3 Copyright (C) 1986-2021 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 #include "common-defs.h"
19 #include "environ.h"
20 #include <algorithm>
21 #include <utility>
22
23 /* See gdbsupport/environ.h. */
24
25 gdb_environ &
operator =(gdb_environ && e)26 gdb_environ::operator= (gdb_environ &&e)
27 {
28 /* Are we self-moving? */
29 if (&e == this)
30 return *this;
31
32 m_environ_vector = std::move (e.m_environ_vector);
33 m_user_set_env = std::move (e.m_user_set_env);
34 m_user_unset_env = std::move (e.m_user_unset_env);
35 e.m_environ_vector.clear ();
36 e.m_environ_vector.push_back (NULL);
37 e.m_user_set_env.clear ();
38 e.m_user_unset_env.clear ();
39 return *this;
40 }
41
42 /* See gdbsupport/environ.h. */
43
from_host_environ()44 gdb_environ gdb_environ::from_host_environ ()
45 {
46 extern char **environ;
47 gdb_environ e;
48
49 if (environ == NULL)
50 return e;
51
52 for (int i = 0; environ[i] != NULL; ++i)
53 {
54 /* Make sure we add the element before the last (NULL). */
55 e.m_environ_vector.insert (e.m_environ_vector.end () - 1,
56 xstrdup (environ[i]));
57 }
58
59 return e;
60 }
61
62 /* See gdbsupport/environ.h. */
63
64 void
clear()65 gdb_environ::clear ()
66 {
67 for (char *v : m_environ_vector)
68 xfree (v);
69 m_environ_vector.clear ();
70 /* Always add the NULL element. */
71 m_environ_vector.push_back (NULL);
72 m_user_set_env.clear ();
73 m_user_unset_env.clear ();
74 }
75
76 /* Helper function to check if STRING contains an environment variable
77 assignment of VAR, i.e., if STRING starts with 'VAR='. Return true
78 if it contains, false otherwise. */
79
80 static bool
match_var_in_string(const char * string,const char * var,size_t var_len)81 match_var_in_string (const char *string, const char *var, size_t var_len)
82 {
83 if (strncmp (string, var, var_len) == 0 && string[var_len] == '=')
84 return true;
85
86 return false;
87 }
88
89 /* See gdbsupport/environ.h. */
90
91 const char *
get(const char * var) const92 gdb_environ::get (const char *var) const
93 {
94 size_t len = strlen (var);
95
96 for (char *el : m_environ_vector)
97 if (el != NULL && match_var_in_string (el, var, len))
98 return &el[len + 1];
99
100 return NULL;
101 }
102
103 /* See gdbsupport/environ.h. */
104
105 void
set(const char * var,const char * value)106 gdb_environ::set (const char *var, const char *value)
107 {
108 char *fullvar = concat (var, "=", value, (char *) NULL);
109
110 /* We have to unset the variable in the vector if it exists. */
111 unset (var, false);
112
113 /* Insert the element before the last one, which is always NULL. */
114 m_environ_vector.insert (m_environ_vector.end () - 1, fullvar);
115
116 /* Mark this environment variable as having been set by the user.
117 This will be useful when we deal with setting environment
118 variables on the remote target. */
119 m_user_set_env.insert (std::string (fullvar));
120
121 /* If this environment variable is marked as unset by the user, then
122 remove it from the list, because now the user wants to set
123 it. */
124 m_user_unset_env.erase (std::string (var));
125 }
126
127 /* See gdbsupport/environ.h. */
128
129 void
unset(const char * var,bool update_unset_list)130 gdb_environ::unset (const char *var, bool update_unset_list)
131 {
132 size_t len = strlen (var);
133 std::vector<char *>::iterator it_env;
134
135 /* We iterate until '.end () - 1' because the last element is
136 always NULL. */
137 for (it_env = m_environ_vector.begin ();
138 it_env != m_environ_vector.end () - 1;
139 ++it_env)
140 if (match_var_in_string (*it_env, var, len))
141 break;
142
143 if (it_env != m_environ_vector.end () - 1)
144 {
145 m_user_set_env.erase (std::string (*it_env));
146 xfree (*it_env);
147
148 m_environ_vector.erase (it_env);
149 }
150
151 if (update_unset_list)
152 m_user_unset_env.insert (std::string (var));
153 }
154
155 /* See gdbsupport/environ.h. */
156
157 void
unset(const char * var)158 gdb_environ::unset (const char *var)
159 {
160 unset (var, true);
161 }
162
163 /* See gdbsupport/environ.h. */
164
165 char **
envp() const166 gdb_environ::envp () const
167 {
168 return const_cast<char **> (&m_environ_vector[0]);
169 }
170
171 /* See gdbsupport/environ.h. */
172
173 const std::set<std::string> &
user_set_env() const174 gdb_environ::user_set_env () const
175 {
176 return m_user_set_env;
177 }
178
179 const std::set<std::string> &
user_unset_env() const180 gdb_environ::user_unset_env () const
181 {
182 return m_user_unset_env;
183 }
184