xref: /netbsd-src/external/gpl3/gdb/dist/gdbsupport/scoped_fd.h (revision 5ba1f45f2a09259cc846f20c7c5501604d633c90)
18dffb485Schristos /* scoped_fd, automatically close a file descriptor
28dffb485Schristos 
3*5ba1f45fSchristos    Copyright (C) 2018-2024 Free Software Foundation, Inc.
48dffb485Schristos 
58dffb485Schristos    This file is part of GDB.
68dffb485Schristos 
78dffb485Schristos    This program is free software; you can redistribute it and/or modify
88dffb485Schristos    it under the terms of the GNU General Public License as published by
98dffb485Schristos    the Free Software Foundation; either version 3 of the License, or
108dffb485Schristos    (at your option) any later version.
118dffb485Schristos 
128dffb485Schristos    This program is distributed in the hope that it will be useful,
138dffb485Schristos    but WITHOUT ANY WARRANTY; without even the implied warranty of
148dffb485Schristos    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
158dffb485Schristos    GNU General Public License for more details.
168dffb485Schristos 
178dffb485Schristos    You should have received a copy of the GNU General Public License
188dffb485Schristos    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
198dffb485Schristos 
208dffb485Schristos #ifndef COMMON_SCOPED_FD_H
218dffb485Schristos #define COMMON_SCOPED_FD_H
228dffb485Schristos 
238dffb485Schristos #include <unistd.h>
244b169a6bSchristos #include "gdb_file.h"
258dffb485Schristos 
268dffb485Schristos /* A smart-pointer-like class to automatically close a file descriptor.  */
278dffb485Schristos 
288dffb485Schristos class scoped_fd
298dffb485Schristos {
308dffb485Schristos public:
318dffb485Schristos   explicit scoped_fd (int fd = -1) noexcept : m_fd (fd) {}
328dffb485Schristos 
338dffb485Schristos   scoped_fd (scoped_fd &&other) noexcept
348dffb485Schristos     : m_fd (other.m_fd)
358dffb485Schristos   {
368dffb485Schristos     other.m_fd = -1;
378dffb485Schristos   }
388dffb485Schristos 
398dffb485Schristos   ~scoped_fd ()
408dffb485Schristos   {
418dffb485Schristos     if (m_fd >= 0)
428dffb485Schristos       close (m_fd);
438dffb485Schristos   }
448dffb485Schristos 
458dffb485Schristos   scoped_fd &operator= (scoped_fd &&other)
468dffb485Schristos   {
478dffb485Schristos     if (m_fd != other.m_fd)
488dffb485Schristos       {
498dffb485Schristos 	if (m_fd >= 0)
508dffb485Schristos 	  close (m_fd);
518dffb485Schristos 	m_fd = other.m_fd;
528dffb485Schristos 	other.m_fd = -1;
538dffb485Schristos       }
548dffb485Schristos     return *this;
558dffb485Schristos   }
568dffb485Schristos 
578dffb485Schristos   DISABLE_COPY_AND_ASSIGN (scoped_fd);
588dffb485Schristos 
598dffb485Schristos   ATTRIBUTE_UNUSED_RESULT int release () noexcept
608dffb485Schristos   {
618dffb485Schristos     int fd = m_fd;
628dffb485Schristos     m_fd = -1;
638dffb485Schristos     return fd;
648dffb485Schristos   }
658dffb485Schristos 
668dffb485Schristos   /* Like release, but return a gdb_file_up that owns the file
678dffb485Schristos      descriptor.  On success, this scoped_fd will be released.  On
688dffb485Schristos      failure, return NULL and leave this scoped_fd in possession of
698dffb485Schristos      the fd.  */
708dffb485Schristos   gdb_file_up to_file (const char *mode) noexcept
718dffb485Schristos   {
728dffb485Schristos     gdb_file_up result (fdopen (m_fd, mode));
738dffb485Schristos     if (result != nullptr)
748dffb485Schristos       m_fd = -1;
758dffb485Schristos     return result;
768dffb485Schristos   }
778dffb485Schristos 
788dffb485Schristos   int get () const noexcept
798dffb485Schristos   {
808dffb485Schristos     return m_fd;
818dffb485Schristos   }
828dffb485Schristos 
838dffb485Schristos private:
848dffb485Schristos   int m_fd;
858dffb485Schristos };
868dffb485Schristos 
878dffb485Schristos #endif /* COMMON_SCOPED_FD_H */
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