binutils-gdb/gdbsupport/scoped_restore.h
Andrew Burgess 1d506c26d9 Update copyright year range in header of all files managed by GDB
This commit is the result of the following actions:

  - Running gdb/copyright.py to update all of the copyright headers to
    include 2024,

  - Manually updating a few files the copyright.py script told me to
    update, these files had copyright headers embedded within the
    file,

  - Regenerating gdbsupport/Makefile.in to refresh it's copyright
    date,

  - Using grep to find other files that still mentioned 2023.  If
    these files were updated last year from 2022 to 2023 then I've
    updated them this year to 2024.

I'm sure I've probably missed some dates.  Feel free to fix them up as
you spot them.
2024-01-12 15:49:57 +00:00

119 lines
3.6 KiB
C++

/* scoped_restore, a simple class for saving and restoring a value
Copyright (C) 2016-2024 Free Software Foundation, Inc.
This file is part of GDB.
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/>. */
#ifndef COMMON_SCOPED_RESTORE_H
#define COMMON_SCOPED_RESTORE_H
/* Base class for scoped_restore_tmpl. */
class scoped_restore_base
{
public:
/* This informs the (scoped_restore_tmpl<T>) dtor that you no longer
want the original value restored. */
void release () const
{ m_saved_var = NULL; }
protected:
scoped_restore_base (void *saved_var)
: m_saved_var (saved_var)
{}
/* The type-erased saved variable. This is here so that clients can
call release() on a "scoped_restore" local, which is a typedef to
a scoped_restore_base. See below. */
mutable void *m_saved_var;
};
/* A convenience typedef. Users of make_scoped_restore declare the
local RAII object as having this type. */
typedef const scoped_restore_base &scoped_restore;
/* An RAII-based object that saves a variable's value, and then
restores it again when this object is destroyed. */
template<typename T>
class scoped_restore_tmpl : public scoped_restore_base
{
public:
/* Create a new scoped_restore object that saves the current value
of *VAR. *VAR will be restored when this scoped_restore object
is destroyed. */
scoped_restore_tmpl (T *var)
: scoped_restore_base (var),
m_saved_value (*var)
{
}
/* Create a new scoped_restore object that saves the current value
of *VAR, and sets *VAR to VALUE. *VAR will be restored when this
scoped_restore object is destroyed. This is templated on T2 to
allow passing VALUEs of types convertible to T.
E.g.: T='base'; T2='derived'. */
template <typename T2>
scoped_restore_tmpl (T *var, T2 value)
: scoped_restore_base (var),
m_saved_value (*var)
{
*var = value;
}
scoped_restore_tmpl (const scoped_restore_tmpl<T> &other)
: scoped_restore_base {other.m_saved_var},
m_saved_value (other.m_saved_value)
{
other.m_saved_var = NULL;
}
~scoped_restore_tmpl ()
{
if (saved_var () != NULL)
*saved_var () = m_saved_value;
}
private:
/* Return a pointer to the saved variable with its type
restored. */
T *saved_var ()
{ return static_cast<T *> (m_saved_var); }
/* No need for this. It is intentionally not defined anywhere. */
scoped_restore_tmpl &operator= (const scoped_restore_tmpl &);
/* The saved value. */
const T m_saved_value;
};
/* Make a scoped_restore. This is useful because it lets template
argument deduction work. */
template<typename T>
scoped_restore_tmpl<T> make_scoped_restore (T *var)
{
return scoped_restore_tmpl<T> (var);
}
/* Make a scoped_restore. This is useful because it lets template
argument deduction work. */
template<typename T, typename T2>
scoped_restore_tmpl<T> make_scoped_restore (T *var, T2 value)
{
return scoped_restore_tmpl<T> (var, value);
}
#endif /* COMMON_SCOPED_RESTORE_H */