[PATCH] Notify observers that directories have changed when using "directory" CLI command

[Andrew Burgess]

Hi,

Thanks for working on this.  This does look like a good change,
however, I have a couple of questions...

* Jan Vrany via Gdb-patches <gdb-patches@sourceware.org> [2020-10-01 13:52:47 +0100]:

> gdb/ChangeLog
> 
> 	* source.c (directory_command): Notify observers that "directories"
> 	parameter has changed.
> 
> gdb/testsuite/ChangeLog
> 
> 	* gdb.mi/mi-cmd-param-changed.exp: Check that notification is
> 	is emmited for both 'set directories' and 'directory' commands.
> ---
>  gdb/ChangeLog                                 | 5 +++++
>  gdb/source.c                                  | 1 +
>  gdb/testsuite/ChangeLog                       | 5 +++++
>  gdb/testsuite/gdb.mi/mi-cmd-param-changed.exp | 8 ++++++++
>  4 files changed, 19 insertions(+)
> 
> diff --git a/gdb/ChangeLog b/gdb/ChangeLog
> index 9c802c57ef..259cdd1981 100644
> --- a/gdb/ChangeLog
> +++ b/gdb/ChangeLog
> @@ -1,3 +1,8 @@
> +2020-10-01  Jan Vrany  <jan.vrany@labware.com>
> +
> +	* source.c (directory_command): Notify observers that "directories"
> +	parameter has changed.
> +
>  2020-09-29  Tom Tromey  <tom@tromey.com>
>  
>  	* dwarf2/read.c (lookup_dwo_id, get_type_unit_group)
> diff --git a/gdb/source.c b/gdb/source.c
> index 0c2b5a4f83..131aebb09b 100644
> --- a/gdb/source.c
> +++ b/gdb/source.c
> @@ -460,6 +460,7 @@ directory_command (const char *dirname, int from_tty)
>      {
>        mod_path (dirname, &source_path);
>        forget_cached_source_info ();
> +      gdb::observers::command_param_changed.notify ("directories", source_path);

I wonder why you only notify in this one case, I've copied the whole
of directory_command below and added an annotation for where I think a
second notification could/should go:

  static void
  directory_command (const char *dirname, int from_tty)
  {
    dont_repeat ();
    /* FIXME, this goes to "delete dir"...  */
    if (dirname == 0)
      {
        if (!from_tty || query (_("Reinitialize source path to empty? ")))
  	{
  	  xfree (source_path);
  	  init_source_path ();
          /* Why not notify here too?  */
  	}
      }
    else
      {
        mod_path (dirname, &source_path);
        forget_cached_source_info ();
        gdb::observers::command_param_changed.notify ("directories", source_path);
      }
    if (from_tty)
      show_directories_1 ((char *) 0, from_tty);
  }

I'd be tempted to only have a single call to notify myself, something
like:

  static void
  directory_command (const char *dirname, int from_tty)
  {
    bool value_changed = false;
    dont_repeat ();
    /* FIXME, this goes to "delete dir"...  */
    if (dirname == 0)
      {
        if (!from_tty || query (_("Reinitialize source path to empty? ")))
  	{
  	  xfree (source_path);
  	  init_source_path ();
          value_changed = true;
  	}
      }
    else
      {
        mod_path (dirname, &source_path);
        forget_cached_source_info ();
        value_changed = true;
      }
    if (value_changed)				/* I added this.  */
      gdb::observers::command_param_changed.notify ("directories", source_path);
    if (from_tty && value_changed)		/* I changed this too.  */
      show_directories_1 ((char *) 0, from_tty);
  }

>      }
>    if (from_tty)
>      show_directories_1 ((char *) 0, from_tty);
> diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
> index 2046c9b8e6..f39c8eb7c7 100644
> --- a/gdb/testsuite/ChangeLog
> +++ b/gdb/testsuite/ChangeLog
> @@ -1,3 +1,8 @@
> +2020-10-01  Jan Vrany  <jan.vrany@labware.com>
> +
> +	* gdb.mi/mi-cmd-param-changed.exp: Check that notification is
> +	is emmited for both 'set directories' and 'directory' commands.
> +
>  2020-09-30  Gary Benson <gbenson@redhat.com>
>  
>  	* gdb.dwarf2/dw2-double-set-die-type.S (.Ldie_3e0):
> diff --git a/gdb/testsuite/gdb.mi/mi-cmd-param-changed.exp b/gdb/testsuite/gdb.mi/mi-cmd-param-changed.exp
> index 031d396dba..78795dc293 100644
> --- a/gdb/testsuite/gdb.mi/mi-cmd-param-changed.exp
> +++ b/gdb/testsuite/gdb.mi/mi-cmd-param-changed.exp
> @@ -102,6 +102,14 @@ proc test_command_param_changed { } {
>  	    ".*=cmd-param-changed,param=\"check type\",value=\"on\".*\\^done" \
>  	    "\"set ch type on\""
>  
> +	# Notification is emitted for both 'set directories' and 'directory'.
> +	mi_gdb_test "set directories \$cdir:\$cwd:/tmp" \
> +	    ".*=cmd-param-changed,param=\"directories\",value=\".*\".*\\^done" \
> +	    "\"set directories\""
> +	mi_gdb_test "directory /usr/src/gdb" \
> +	    ".*=cmd-param-changed,param=\"directories\",value=\".*\".*\\^done" \
> +	    "\"directory\""
> +

I'd like to see a test for using `directories` with no arguments too.

Thanks,
Andrew


>  	mi_gdb_exit
>      }
>  }
> -- 
> 2.28.0
>