0fa7617d84
I recently learned that move constructors generally should be marked "noexcept". This ensures that standard containers will move objects when possible, rather than copy them. This patch fixes the cases I could find. Note that implicitly-defined or defaulted move constructors will automatically do what you'd expect; that is, they are noexcept if all the members have noexcept move constructors. While doing this, I noticed a couple of odd cases where the move constructor seemed to assume that the object being constructed could have state requiring destruction. I've fixed these as well. See completion_result and scoped_mmap. gdb/ChangeLog 2020-04-20 Tom Tromey <tromey@adacore.com> * python/python.c (struct gdbpy_event): Mark move constructor as noexcept. * python/py-tui.c (class gdbpy_tui_window_maker): Mark move constructor as noexcept. * completer.h (struct completion_result): Mark move constructor as noexcept. * completer.c (completion_result::completion_result): Use initialization style. Don't call reset_match_list. gdbsupport/ChangeLog 2020-04-20 Tom Tromey <tromey@adacore.com> * scoped_mmap.h (scoped_mmap): Mark move constructor as noexcept. Use initialization style. Don't call destroy. * scoped_fd.h (class scoped_fd): Mark move constructor as noexcept. * gdb_ref_ptr.h (class ref_ptr): Mark move constructor as noexcept.
88 lines
2.0 KiB
C++
88 lines
2.0 KiB
C++
/* scoped_fd, automatically close a file descriptor
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Copyright (C) 2018-2020 Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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#ifndef COMMON_SCOPED_FD_H
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#define COMMON_SCOPED_FD_H
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#include <unistd.h>
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#include "filestuff.h"
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/* A smart-pointer-like class to automatically close a file descriptor. */
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class scoped_fd
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{
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public:
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explicit scoped_fd (int fd = -1) noexcept : m_fd (fd) {}
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scoped_fd (scoped_fd &&other) noexcept
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: m_fd (other.m_fd)
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{
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other.m_fd = -1;
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}
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~scoped_fd ()
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{
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if (m_fd >= 0)
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close (m_fd);
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}
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scoped_fd &operator= (scoped_fd &&other)
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{
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if (m_fd != other.m_fd)
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{
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if (m_fd >= 0)
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close (m_fd);
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m_fd = other.m_fd;
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other.m_fd = -1;
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}
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return *this;
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}
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DISABLE_COPY_AND_ASSIGN (scoped_fd);
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ATTRIBUTE_UNUSED_RESULT int release () noexcept
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{
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int fd = m_fd;
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m_fd = -1;
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return fd;
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}
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/* Like release, but return a gdb_file_up that owns the file
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descriptor. On success, this scoped_fd will be released. On
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failure, return NULL and leave this scoped_fd in possession of
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the fd. */
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gdb_file_up to_file (const char *mode) noexcept
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{
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gdb_file_up result (fdopen (m_fd, mode));
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if (result != nullptr)
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m_fd = -1;
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return result;
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}
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int get () const noexcept
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{
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return m_fd;
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}
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private:
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int m_fd;
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};
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#endif /* COMMON_SCOPED_FD_H */
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