binutils-gdb/gdbsupport/scoped_ignore_sigttou.h
Lancelot Six 6b09f1342c gdb: Replace gdb::optional with std::optional
Since GDB now requires C++17, we don't need the internally maintained
gdb::optional implementation.  This patch does the following replacing:
  - gdb::optional -> std::optional
  - gdb::in_place -> std::in_place
  - #include "gdbsupport/gdb_optional.h" -> #include <optional>

This change has mostly been done automatically.  One exception is
gdbsupport/thread-pool.* which did not use the gdb:: prefix as it
already lives in the gdb namespace.

Change-Id: I19a92fa03e89637bab136c72e34fd351524f65e9
Approved-By: Tom Tromey <tom@tromey.com>
Approved-By: Pedro Alves <pedro@palves.net>
2023-11-21 11:52:35 +00:00

88 lines
2.0 KiB
C++

/* Support for ignoring SIGTTOU.
Copyright (C) 2003-2023 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 */