1 /* Support for signoring SIGTTOU. 2 3 Copyright (C) 2003-2023 Free Software Foundation, Inc. 4 5 This file is part of GDB. 6 7 This program is free software; you can redistribute it and/or modify 8 it under the terms of the GNU General Public License as published by 9 the Free Software Foundation; either version 3 of the License, or 10 (at your option) any later version. 11 12 This program is distributed in the hope that it will be useful, 13 but WITHOUT ANY WARRANTY; without even the implied warranty of 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 GNU General Public License for more details. 16 17 You should have received a copy of the GNU General Public License 18 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 19 20 #ifndef SCOPED_IGNORE_SIGTTOU_H 21 #define SCOPED_IGNORE_SIGTTOU_H 22 23 #include "gdbsupport/scoped_ignore_signal.h" 24 #include "gdbsupport/job-control.h" 25 26 #ifdef SIGTTOU 27 28 /* Simple wrapper that allows lazy initialization / destruction of T. 29 Slightly more efficient than gdb::optional, because it doesn't 30 carry storage to track whether the object has been initialized. */ 31 template<typename T> 32 class lazy_init 33 { 34 public: 35 void emplace () 36 { 37 new (&m_u.obj) T (); 38 } 39 40 void reset () 41 { 42 m_u.obj.~T (); 43 } 44 45 private: 46 union u 47 { 48 /* Must define ctor/dtor if T has non-trivial ctor/dtor. */ 49 u () {} 50 ~u () {} 51 52 T obj; 53 } m_u; 54 }; 55 56 /* RAII class used to ignore SIGTTOU in a scope. This isn't simply 57 scoped_ignore_signal<SIGTTOU> because we want to check the 58 `job_control' global. */ 59 60 class scoped_ignore_sigttou 61 { 62 public: 63 scoped_ignore_sigttou () 64 { 65 if (job_control) 66 m_ignore_signal.emplace (); 67 } 68 69 ~scoped_ignore_sigttou () 70 { 71 if (job_control) 72 m_ignore_signal.reset (); 73 } 74 75 DISABLE_COPY_AND_ASSIGN (scoped_ignore_sigttou); 76 77 private: 78 lazy_init<scoped_ignore_signal<SIGTTOU, false>> m_ignore_signal; 79 }; 80 81 #else 82 83 using scoped_ignore_sigttou = scoped_ignore_signal_nop; 84 85 #endif 86 87 #endif /* SCOPED_IGNORE_SIGTTOU_H */ 88