From: Pedro Alves <palves@redhat.com>
To: Tom Tromey <tom@tromey.com>, gdb-patches@sourceware.org
Subject: Re: [RFA 09/23] Remove close cleanup
Date: Fri, 02 Jun 2017 18:08:00 -0000 [thread overview]
Message-ID: <ca2efb7d-21f7-f935-fbe3-86d09916d0f0@redhat.com> (raw)
In-Reply-To: <20170503224626.2818-10-tom@tromey.com>
Patch looks good.
The bit below made me stop for a second:
On 05/03/2017 11:46 PM, Tom Tromey wrote:
> @@ -901,64 +900,59 @@ linux_mntns_access_fs (pid_t pid)
> if (ns == NULL)
> return MNSH_FS_DIRECT;
>
> - old_chain = make_cleanup (null_cleanup, NULL);
> -
> fd = gdb_open_cloexec (linux_ns_filename (ns, pid), O_RDONLY, 0);
> if (fd < 0)
> - goto error;
> -
> - make_cleanup_close (fd);
> + return MNSH_FS_ERROR;
>
> - if (fstat (fd, &sb) != 0)
> - goto error;
> + /* Introduce a new scope here so we can reset errno after
> + closing. */
> + {
> + gdb::fd_closer close_fd (fd);
>
Would the following be too clever?
/* Restore errno on exit to the value saved by the
last save() call. Ctor saves. */
struct scoped_errno_restore
{
scoped_errno_restore () { save (); }
~scoped_errno_restore () { errno = m_value; }
/* Take a snapshot of current errno. */
void save () { m_value = errno; }
private:
int m_value;
};
scoped_errno_restore restore_errno;
gdb::fd_closer close_fd (fd);
/* Save errno and return MNSH_FS_ERROR. */
auto fs_err = [&] ()
{
restore_errno.save ();
return MNSH_FS_ERROR;
};
if (fstat (fd, &sb) != 0)
return fs_err ();
(...)
helper = linux_mntns_get_helper ();
if (helper == NULL)
return fs_err ();
size = mnsh_send_setns (helper, fd, 0);
if (size < 0)
return fs_err ();
[It gets rid of both the scope, and the gotos.]
Thanks,
Pedro Alves
next prev parent reply other threads:[~2017-06-02 18:08 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-03 22:46 [RFA 00/23] More miscellaneous C++-ification Tom Tromey
2017-05-03 22:46 ` [RFA 23/23] Use gdb_argv_up in Python Tom Tromey
2017-06-05 16:29 ` Pedro Alves
2017-07-19 22:52 ` Tom Tromey
2017-07-19 22:51 ` Tom Tromey
2017-05-03 22:46 ` [RFA 09/23] Remove close cleanup Tom Tromey
2017-06-02 18:08 ` Pedro Alves [this message]
2017-07-19 22:52 ` Tom Tromey
2017-07-31 19:08 ` Simon Marchi
2017-08-01 21:52 ` Tom Tromey
2017-05-03 22:46 ` [RFA 02/23] Introduce and use gdb_file_up Tom Tromey
2017-06-02 17:08 ` Pedro Alves
2017-05-03 22:46 ` [RFA 12/23] More uses of scoped_restore Tom Tromey
2017-06-02 18:31 ` Pedro Alves
2017-05-03 22:46 ` [RFA 20/23] Avoid some manual memory management in Python Tom Tromey
2017-06-05 13:55 ` Pedro Alves
2017-05-03 22:46 ` [RFA 01/23] Introduce and use ui_out_emit_table Tom Tromey
2017-06-02 17:04 ` Pedro Alves
2017-05-03 22:46 ` [RFA 10/23] Remove make_cleanup_restore_current_language Tom Tromey
2017-06-02 18:18 ` Pedro Alves
2017-06-05 13:09 ` Tom Tromey
2017-05-03 22:46 ` [RFA 03/23] Use gdb_file_up in find_and_open_script Tom Tromey
2017-06-02 17:24 ` Pedro Alves
2017-07-23 16:08 ` Tom Tromey
2017-05-03 22:46 ` [RFA 04/23] Use gdb_file_up in fbsd-nat.c Tom Tromey
2017-05-03 23:52 ` John Baldwin
2017-05-03 22:46 ` [RFA 17/23] Use a scoped_restore for user_call_depth Tom Tromey
2017-06-05 13:32 ` Pedro Alves
2017-06-05 16:56 ` Tom Tromey
2017-05-03 22:46 ` [RFA 13/23] Replace tui_restore_gdbout with scoped_restore Tom Tromey
2017-06-02 18:34 ` Pedro Alves
2017-05-03 22:46 ` [RFA 06/23] Change open_terminal_stream to return a gdb_file_up Tom Tromey
2017-06-02 17:31 ` Pedro Alves
2017-05-03 22:46 ` [RFA 18/23] Use a scoped_restore for command_nest_depth Tom Tromey
2017-06-05 13:38 ` Pedro Alves
2017-05-03 22:46 ` [RFA 16/23] Remove in_user_command Tom Tromey
2017-06-05 13:27 ` Pedro Alves
2017-05-03 22:46 ` [RFA 19/23] Replace do_restore_instream_cleanup with scoped_restore Tom Tromey
2017-06-05 13:49 ` Pedro Alves
2017-05-03 22:46 ` [RFA 05/23] Use gdb_file_up in source.c Tom Tromey
2017-06-02 17:27 ` Pedro Alves
2017-05-03 22:46 ` [RFA 15/23] Use std::vector to avoid cleanups Tom Tromey
2017-06-02 19:22 ` Pedro Alves
2017-07-23 16:06 ` Tom Tromey
2017-05-03 22:46 ` [RFA 07/23] Remove make_cleanup_fclose Tom Tromey
2017-06-02 17:32 ` Pedro Alves
2017-05-03 22:46 ` [RFA 14/23] Use unique_xmalloc_ptr in jit.c Tom Tromey
2017-06-02 18:42 ` Pedro Alves
2017-06-05 13:09 ` Tom Tromey
2017-05-03 22:46 ` [RFA 21/23] Remove a cleanup in Python Tom Tromey
2017-06-05 13:56 ` Pedro Alves
2017-05-03 22:46 ` [RFA 08/23] Remove an unlink cleanup Tom Tromey
2017-06-02 17:37 ` Pedro Alves
2017-05-03 22:46 ` [RFA 22/23] Make gdb_buildargv return a unique pointer Tom Tromey
2017-06-05 16:21 ` Pedro Alves
2017-07-23 17:26 ` Tom Tromey
2017-05-03 22:46 ` [RFA 11/23] Remove make_cleanup_free_so Tom Tromey
2017-06-02 18:25 ` Pedro Alves
2017-05-29 17:31 ` [RFA 00/23] More miscellaneous C++-ification Tom Tromey
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