1 /* environ.c -- library for manipulating environments for GNU. 2 3 Copyright (C) 1986-2024 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 "environ.h" 19 #include <algorithm> 20 #include <utility> 21 22 /* See gdbsupport/environ.h. */ 23 24 gdb_environ & 25 gdb_environ::operator= (gdb_environ &&e) 26 { 27 /* Are we self-moving? */ 28 if (&e == this) 29 return *this; 30 31 this->clear (); 32 33 m_environ_vector = std::move (e.m_environ_vector); 34 m_user_set_env = std::move (e.m_user_set_env); 35 m_user_unset_env = std::move (e.m_user_unset_env); 36 e.m_environ_vector.clear (); 37 e.m_environ_vector.push_back (NULL); 38 e.m_user_set_env.clear (); 39 e.m_user_unset_env.clear (); 40 return *this; 41 } 42 43 /* See gdbsupport/environ.h. */ 44 45 gdb_environ gdb_environ::from_host_environ () 46 { 47 extern char **environ; 48 gdb_environ e; 49 50 if (environ == NULL) 51 return e; 52 53 for (int i = 0; environ[i] != NULL; ++i) 54 { 55 /* Make sure we add the element before the last (NULL). */ 56 e.m_environ_vector.insert (e.m_environ_vector.end () - 1, 57 xstrdup (environ[i])); 58 } 59 60 return e; 61 } 62 63 /* See gdbsupport/environ.h. */ 64 65 void 66 gdb_environ::clear () 67 { 68 for (char *v : m_environ_vector) 69 xfree (v); 70 m_environ_vector.clear (); 71 /* Always add the NULL element. */ 72 m_environ_vector.push_back (NULL); 73 m_user_set_env.clear (); 74 m_user_unset_env.clear (); 75 } 76 77 /* Helper function to check if STRING contains an environment variable 78 assignment of VAR, i.e., if STRING starts with 'VAR='. Return true 79 if it contains, false otherwise. */ 80 81 static bool 82 match_var_in_string (const char *string, const char *var, size_t var_len) 83 { 84 if (strncmp (string, var, var_len) == 0 && string[var_len] == '=') 85 return true; 86 87 return false; 88 } 89 90 /* See gdbsupport/environ.h. */ 91 92 const char * 93 gdb_environ::get (const char *var) const 94 { 95 size_t len = strlen (var); 96 97 for (char *el : m_environ_vector) 98 if (el != NULL && match_var_in_string (el, var, len)) 99 return &el[len + 1]; 100 101 return NULL; 102 } 103 104 /* See gdbsupport/environ.h. */ 105 106 void 107 gdb_environ::set (const char *var, const char *value) 108 { 109 char *fullvar = concat (var, "=", value, (char *) NULL); 110 111 /* We have to unset the variable in the vector if it exists. */ 112 unset (var, false); 113 114 /* Insert the element before the last one, which is always NULL. */ 115 m_environ_vector.insert (m_environ_vector.end () - 1, fullvar); 116 117 /* Mark this environment variable as having been set by the user. 118 This will be useful when we deal with setting environment 119 variables on the remote target. */ 120 m_user_set_env.insert (std::string (fullvar)); 121 122 /* If this environment variable is marked as unset by the user, then 123 remove it from the list, because now the user wants to set 124 it. */ 125 m_user_unset_env.erase (std::string (var)); 126 } 127 128 /* See gdbsupport/environ.h. */ 129 130 void 131 gdb_environ::unset (const char *var, bool update_unset_list) 132 { 133 size_t len = strlen (var); 134 std::vector<char *>::iterator it_env; 135 136 /* We iterate until '.end () - 1' because the last element is 137 always NULL. */ 138 for (it_env = m_environ_vector.begin (); 139 it_env != m_environ_vector.end () - 1; 140 ++it_env) 141 if (match_var_in_string (*it_env, var, len)) 142 break; 143 144 if (it_env != m_environ_vector.end () - 1) 145 { 146 m_user_set_env.erase (std::string (*it_env)); 147 xfree (*it_env); 148 149 m_environ_vector.erase (it_env); 150 } 151 152 if (update_unset_list) 153 m_user_unset_env.insert (std::string (var)); 154 } 155 156 /* See gdbsupport/environ.h. */ 157 158 void 159 gdb_environ::unset (const char *var) 160 { 161 unset (var, true); 162 } 163 164 /* See gdbsupport/environ.h. */ 165 166 char ** 167 gdb_environ::envp () const 168 { 169 return const_cast<char **> (&m_environ_vector[0]); 170 } 171 172 /* See gdbsupport/environ.h. */ 173 174 const std::set<std::string> & 175 gdb_environ::user_set_env () const 176 { 177 return m_user_set_env; 178 } 179 180 const std::set<std::string> & 181 gdb_environ::user_unset_env () const 182 { 183 return m_user_unset_env; 184 } 185