1/* Header for environment manipulation library.
2   Copyright (C) 1989-2023 Free Software Foundation, Inc.
3
4   This program is free software; you can redistribute it and/or modify
5   it under the terms of the GNU General Public License as published by
6   the Free Software Foundation; either version 3 of the License, or
7   (at your option) any later version.
8
9   This program is distributed in the hope that it will be useful,
10   but WITHOUT ANY WARRANTY; without even the implied warranty of
11   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12   GNU General Public License for more details.
13
14   You should have received a copy of the GNU General Public License
15   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
16
17#ifndef COMMON_ENVIRON_H
18#define COMMON_ENVIRON_H
19
20#include <vector>
21#include <set>
22
23/* Class that represents the environment variables as seen by the
24   inferior.  */
25
26class gdb_environ
27{
28public:
29  /* Regular constructor and destructor.  */
30  gdb_environ ()
31  {
32    /* Make sure that the vector contains at least a NULL element.
33       If/when we add more variables to it, NULL will always be the
34       last element.  */
35    m_environ_vector.push_back (NULL);
36  }
37
38  ~gdb_environ ()
39  {
40    clear ();
41  }
42
43  /* Move constructor.  */
44  gdb_environ (gdb_environ &&e)
45    : m_environ_vector (std::move (e.m_environ_vector)),
46      m_user_set_env (std::move (e.m_user_set_env)),
47      m_user_unset_env (std::move (e.m_user_unset_env))
48  {
49    /* Make sure that the moved-from vector is left at a valid
50       state (only one NULL element).  */
51    e.m_environ_vector.clear ();
52    e.m_environ_vector.push_back (NULL);
53    e.m_user_set_env.clear ();
54    e.m_user_unset_env.clear ();
55  }
56
57  /* Move assignment.  */
58  gdb_environ &operator= (gdb_environ &&e);
59
60  /* Create a gdb_environ object using the host's environment
61     variables.  */
62  static gdb_environ from_host_environ ();
63
64  /* Clear the environment variables stored in the object.  */
65  void clear ();
66
67  /* Return the value in the environment for the variable VAR.  The
68     returned pointer is only valid as long as the gdb_environ object
69     is not modified.  */
70  const char *get (const char *var) const;
71
72  /* Store VAR=VALUE in the environment.  */
73  void set (const char *var, const char *value);
74
75  /* Unset VAR in environment.  */
76  void unset (const char *var);
77
78  /* Return the environment vector represented as a 'char **'.  */
79  char **envp () const;
80
81  /* Return the user-set environment vector.  */
82  const std::set<std::string> &user_set_env () const;
83
84  /* Return the user-unset environment vector.  */
85  const std::set<std::string> &user_unset_env () const;
86
87private:
88  /* Unset VAR in environment.  If UPDATE_UNSET_LIST is true, then
89     also update M_USER_UNSET_ENV to reflect the unsetting of the
90     environment variable.  */
91  void unset (const char *var, bool update_unset_list);
92
93  /* A vector containing the environment variables.  */
94  std::vector<char *> m_environ_vector;
95
96  /* The environment variables explicitly set by the user.  */
97  std::set<std::string> m_user_set_env;
98
99  /* The environment variables explicitly unset by the user.  */
100  std::set<std::string> m_user_unset_env;
101};
102
103#endif /* COMMON_ENVIRON_H */
104