Re: [PATCH v2 07/22] Remove last cleanups from solib-svr4.c

[Pedro Alves <palves at redhat dot com>]

On 02/27/2019 08:18 PM, Tom Tromey wrote:
> This removes the last cleanups from solib-svr4.c, replacing them with
> uses of make_scope_exit.
> 
> gdb/ChangeLog
> 2019-02-27  Tom Tromey  <tom@tromey.com>
> 
> 	* solib-svr4.c (svr4_parse_libraries, svr4_current_sos_direct):
> 	Use make_scope_exit.
> ---
>  gdb/ChangeLog    |  5 +++++
>  gdb/solib-svr4.c | 17 ++++++++++-------
>  2 files changed, 15 insertions(+), 7 deletions(-)
> 
> diff --git a/gdb/solib-svr4.c b/gdb/solib-svr4.c
> index 2b370ef96d0..2301cf94c2f 100644
> --- a/gdb/solib-svr4.c
> +++ b/gdb/solib-svr4.c
> @@ -1198,8 +1198,10 @@ static const struct gdb_xml_element svr4_library_list_elements[] =
>  static int
>  svr4_parse_libraries (const char *document, struct svr4_library_list *list)
>  {
> -  struct cleanup *back_to = make_cleanup (svr4_free_library_list,
> -					  &list->head);
> +  auto cleanup = make_scope_exit ([&] ()
> +				  {
> +				    svr4_free_library_list (&list->head);
> +				  });
>  

When passing lambdas as last argument to a function, I think indenting
like this reads clearer:

  auto cleanup = make_scope_exit ([&] ()
    {
      svr4_free_library_list (&list->head);
    });

Makes it read more like an if/for scope block, and of course,
avoids aligning things too much to the right side.  Examples of
this can be found throughout gdbserver, for example:

	  for_each_thread ([] (thread_info *thread)
	    {
	      thread->status_pending_p = 0;
	    });

and, also, that's how you'd indent if you used SCOPE_EXIT instead:

  SCOPE_EXIT
    {
      svr4_free_library_list (&list->head);
    }

LLVM has a written rule for this:

 https://llvm.org/docs/CodingStandards.html#format-lambdas-like-blocks-of-code

If others agree, I'd vote for having a similar rule of our own.

Otherwise, LGTM.

Thanks,
Pedro Alves