binutils-gdb/gdb/common/environ.c
Sergio Durigan Junior d4c6ce5b01 Update comment on gdb_environ::unset
gdb_environ::unset iterates using '.end () - 1' now, instead of '.cend
() - 1'.  This obvious patch updates the comment.

gdb/ChangeLog:
2017-06-22  Sergio Durigan Junior  <sergiodj@redhat.com>

	* common/environ.c (gdb_environ::unset): Update comment.
2017-06-22 14:50:24 -04:00

137 lines
3.2 KiB
C

/* environ.c -- library for manipulating environments for GNU.
Copyright (C) 1986-2017 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include "common-defs.h"
#include "environ.h"
#include <algorithm>
#include <utility>
/* See common/environ.h. */
gdb_environ &
gdb_environ::operator= (gdb_environ &&e)
{
/* Are we self-moving? */
if (&e == this)
return *this;
m_environ_vector = std::move (e.m_environ_vector);
e.m_environ_vector.clear ();
e.m_environ_vector.push_back (NULL);
return *this;
}
/* See common/environ.h. */
gdb_environ gdb_environ::from_host_environ ()
{
extern char **environ;
gdb_environ e;
if (environ == NULL)
return e;
for (int i = 0; environ[i] != NULL; ++i)
{
/* Make sure we add the element before the last (NULL). */
e.m_environ_vector.insert (e.m_environ_vector.end () - 1,
xstrdup (environ[i]));
}
return e;
}
/* See common/environ.h. */
void
gdb_environ::clear ()
{
for (char *v : m_environ_vector)
xfree (v);
m_environ_vector.clear ();
/* Always add the NULL element. */
m_environ_vector.push_back (NULL);
}
/* Helper function to check if STRING contains an environment variable
assignment of VAR, i.e., if STRING starts with 'VAR='. Return true
if it contains, false otherwise. */
static bool
match_var_in_string (char *string, const char *var, size_t var_len)
{
if (strncmp (string, var, var_len) == 0 && string[var_len] == '=')
return true;
return false;
}
/* See common/environ.h. */
const char *
gdb_environ::get (const char *var) const
{
size_t len = strlen (var);
for (char *el : m_environ_vector)
if (el != NULL && match_var_in_string (el, var, len))
return &el[len + 1];
return NULL;
}
/* See common/environ.h. */
void
gdb_environ::set (const char *var, const char *value)
{
/* We have to unset the variable in the vector if it exists. */
unset (var);
/* Insert the element before the last one, which is always NULL. */
m_environ_vector.insert (m_environ_vector.end () - 1,
concat (var, "=", value, NULL));
}
/* See common/environ.h. */
void
gdb_environ::unset (const char *var)
{
size_t len = strlen (var);
/* We iterate until '.end () - 1' because the last element is
always NULL. */
for (std::vector<char *>::iterator el = m_environ_vector.begin ();
el != m_environ_vector.end () - 1;
++el)
if (match_var_in_string (*el, var, len))
{
xfree (*el);
m_environ_vector.erase (el);
break;
}
}
/* See common/environ.h. */
char **
gdb_environ::envp () const
{
return const_cast<char **> (&m_environ_vector[0]);
}