gdbsupport/environ.h

   1 /* Header for environment manipulation library.
   2    Copyright (C) 1989-2020 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
  26 class gdb_environ
  27 {
  28 public:
  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
  87 private:
  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 */