1 /* environ.c -- library for manipulating environments for GNU. 2 3 Copyright (C) 1986-2023 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 & 26 gdb_environ::operator= (gdb_environ &&e) 27 { 28 /* Are we self-moving? */ 29 if (&e == this) 30 return *this; 31 32 this->clear (); 33 34 m_environ_vector = std::move (e.m_environ_vector); 35 m_user_set_env = std::move (e.m_user_set_env); 36 m_user_unset_env = std::move (e.m_user_unset_env); 37 e.m_environ_vector.clear (); 38 e.m_environ_vector.push_back (NULL); 39 e.m_user_set_env.clear (); 40 e.m_user_unset_env.clear (); 41 return *this; 42 } 43 44 /* See gdbsupport/environ.h. */ 45 46 gdb_environ gdb_environ::from_host_environ () 47 { 48 extern char **environ; 49 gdb_environ e; 50 51 if (environ == NULL) 52 return e; 53 54 for (int i = 0; environ[i] != NULL; ++i) 55 { 56 /* Make sure we add the element before the last (NULL). */ 57 e.m_environ_vector.insert (e.m_environ_vector.end () - 1, 58 xstrdup (environ[i])); 59 } 60 61 return e; 62 } 63 64 /* See gdbsupport/environ.h. */ 65 66 void 67 gdb_environ::clear () 68 { 69 for (char *v : m_environ_vector) 70 xfree (v); 71 m_environ_vector.clear (); 72 /* Always add the NULL element. */ 73 m_environ_vector.push_back (NULL); 74 m_user_set_env.clear (); 75 m_user_unset_env.clear (); 76 } 77 78 /* Helper function to check if STRING contains an environment variable 79 assignment of VAR, i.e., if STRING starts with 'VAR='. Return true 80 if it contains, false otherwise. */ 81 82 static bool 83 match_var_in_string (const char *string, const char *var, size_t var_len) 84 { 85 if (strncmp (string, var, var_len) == 0 && string[var_len] == '=') 86 return true; 87 88 return false; 89 } 90 91 /* See gdbsupport/environ.h. */ 92 93 const char * 94 gdb_environ::get (const char *var) const 95 { 96 size_t len = strlen (var); 97 98 for (char *el : m_environ_vector) 99 if (el != NULL && match_var_in_string (el, var, len)) 100 return &el[len + 1]; 101 102 return NULL; 103 } 104 105 /* See gdbsupport/environ.h. */ 106 107 void 108 gdb_environ::set (const char *var, const char *value) 109 { 110 char *fullvar = concat (var, "=", value, (char *) NULL); 111 112 /* We have to unset the variable in the vector if it exists. */ 113 unset (var, false); 114 115 /* Insert the element before the last one, which is always NULL. */ 116 m_environ_vector.insert (m_environ_vector.end () - 1, fullvar); 117 118 /* Mark this environment variable as having been set by the user. 119 This will be useful when we deal with setting environment 120 variables on the remote target. */ 121 m_user_set_env.insert (std::string (fullvar)); 122 123 /* If this environment variable is marked as unset by the user, then 124 remove it from the list, because now the user wants to set 125 it. */ 126 m_user_unset_env.erase (std::string (var)); 127 } 128 129 /* See gdbsupport/environ.h. */ 130 131 void 132 gdb_environ::unset (const char *var, bool update_unset_list) 133 { 134 size_t len = strlen (var); 135 std::vector<char *>::iterator it_env; 136 137 /* We iterate until '.end () - 1' because the last element is 138 always NULL. */ 139 for (it_env = m_environ_vector.begin (); 140 it_env != m_environ_vector.end () - 1; 141 ++it_env) 142 if (match_var_in_string (*it_env, var, len)) 143 break; 144 145 if (it_env != m_environ_vector.end () - 1) 146 { 147 m_user_set_env.erase (std::string (*it_env)); 148 xfree (*it_env); 149 150 m_environ_vector.erase (it_env); 151 } 152 153 if (update_unset_list) 154 m_user_unset_env.insert (std::string (var)); 155 } 156 157 /* See gdbsupport/environ.h. */ 158 159 void 160 gdb_environ::unset (const char *var) 161 { 162 unset (var, true); 163 } 164 165 /* See gdbsupport/environ.h. */ 166 167 char ** 168 gdb_environ::envp () const 169 { 170 return const_cast<char **> (&m_environ_vector[0]); 171 } 172 173 /* See gdbsupport/environ.h. */ 174 175 const std::set<std::string> & 176 gdb_environ::user_set_env () const 177 { 178 return m_user_set_env; 179 } 180 181 const std::set<std::string> & 182 gdb_environ::user_unset_env () const 183 { 184 return m_user_unset_env; 185 } 186