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/* Support for ignoring SIGTTOU.
Copyright (C) 2003-2024 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 SCOPED_IGNORE_SIGTTOU_H
#define SCOPED_IGNORE_SIGTTOU_H
#include "gdbsupport/scoped_ignore_signal.h"
#include "gdbsupport/job-control.h"
#ifdef SIGTTOU
/* Simple wrapper that allows lazy initialization / destruction of T.
Slightly more efficient than std::optional, because it doesn't
carry storage to track whether the object has been initialized. */
template<typename T>
class lazy_init
{
public:
void emplace ()
{
new (&m_u.obj) T ();
}
void reset ()
{
m_u.obj.~T ();
}
private:
union u
{
/* Must define ctor/dtor if T has non-trivial ctor/dtor. */
u () {}
~u () {}
T obj;
} m_u;
};
/* RAII class used to ignore SIGTTOU in a scope. This isn't simply
scoped_ignore_signal<SIGTTOU> because we want to check the
`job_control' global. */
class scoped_ignore_sigttou
{
public:
scoped_ignore_sigttou ()
{
if (job_control)
m_ignore_signal.emplace ();
}
~scoped_ignore_sigttou ()
{
if (job_control)
m_ignore_signal.reset ();
}
DISABLE_COPY_AND_ASSIGN (scoped_ignore_sigttou);
private:
lazy_init<scoped_ignore_signal<SIGTTOU, false>> m_ignore_signal;
};
#else
using scoped_ignore_sigttou = scoped_ignore_signal_nop;
#endif
#endif /* SCOPED_IGNORE_SIGTTOU_H */