Ping: Re: [PATCH] switch away from using specify_exec_file_hook

Ping!

Thanks,
Andrew

Andrew Burgess <[email protected]> writes:

> I had a go at testing this patch using make check-gdb
> TESTS="gdb.gdbtk/*.exp", but ran into numerous errors, I suspect that
> the gdbtk testing has not been run in a while, and it certainly
> doesn't appear to have kept up with changes to the GDB testsuite.
>
> If there's any particular testing that I should be running then just
> let me know.
>
> Otherwise, if we could merge this patch, then we can remove a couple
> of functions from GDB that are only used to support this one hook.
>
> ---
>
> Stop using specify_exec_file_hook to spot when the executable GDB is
> debugging changes, and instead use gdb::observers::executable_changed.
>
> The specify_exec_file_hook would call a function with the name of the
> executable as specified by the user, so long as the name of the
> executable wasn't empty, e.g.:
>
>   (gdb) file exec_name
>
> would call the hook with 'exec_name', while:
>
>   (gdb) file
>
> would not call the hook at all.
>
> The observer I'm proposing we switch too is slightly different.  The
> observer is called with the program_space in which the executable
> changed, even in the empty filename case.  The observer also receives
> a flag which indicates if GDB is loading a new executable, or is
> loading the same executable because the on-disk file changed.
>
> To reduce the chance of breakage, within insight, if the new observer
> function is called in the empty filename case I don't call into the
> TCL code, this ensures the TCL code is only called in the same cases a
> previously.
>
> The TCL code will be called with the full path to the executable
> rather than the partial string the user specified, however, the TCL
> code would (in some cases at least) look up the full executable path
> anyway, so I don't think the change should have a negative impact.
>
> For now I'm ignoring the reload_p flag, that is, I call into the TCL
> code both when the executable has completely changed, and when it's
> the same executable filename, but the on-disk file changed, I think
> this matches the behaviour before this patch.
>
> And finally, while looking at the TCL code, I spotted that a comment
> in interface.tcl relating to this code was slightly out of date, I've
> updated the comment.
> ---
>  gdbtk/generic/gdbtk-hooks.c | 16 +++++++++++-----
>  gdbtk/library/interface.tcl |  2 +-
>  2 files changed, 12 insertions(+), 6 deletions(-)
>
> diff --git a/gdbtk/generic/gdbtk-hooks.c b/gdbtk/generic/gdbtk-hooks.c
> index 75e89e7..fe42e7d 100644
> --- a/gdbtk/generic/gdbtk-hooks.c
> +++ b/gdbtk/generic/gdbtk-hooks.c
> @@ -83,7 +83,7 @@ static void gdbtk_trace_start_stop (int, int);
>  static void gdbtk_attach (void);
>  static void gdbtk_detach (void);
>  static void gdbtk_file_changed (const char *);
> -static void gdbtk_exec_file_display (const char *);
> +static void gdbtk_executable_changed (program_space *, bool);
>  static void gdbtk_call_command (struct cmd_list_element *, const char *, int);
>  static void gdbtk_target_pre_wait (ptid_t ptid);
>  static void gdbtk_target_post_wait (ptid_t event_ptid);
> @@ -140,6 +140,8 @@ gdbtk_add_hooks (void)
>                                            "gdbtk-hooks");
>    gdb::observers::target_post_wait.attach (gdbtk_target_post_wait,
>                                             "gdbtk-hooks");
> +  gdb::observers::executable_changed.attach (gdbtk_executable_changed,
> +                                             "gdbtk-hooks");
>  
>    /* Hooks */
>    deprecated_call_command_hook = gdbtk_call_command;
> @@ -157,7 +159,6 @@ gdbtk_add_hooks (void)
>    deprecated_pre_add_symbol_hook = gdbtk_pre_add_symbol;
>    deprecated_post_add_symbol_hook = gdbtk_post_add_symbol;
>    deprecated_file_changed_hook = gdbtk_file_changed;
> -  specify_exec_file_hook (gdbtk_exec_file_display);
>  
>    deprecated_attach_hook            = gdbtk_attach;
>    deprecated_detach_hook            = gdbtk_detach;
> @@ -732,11 +733,16 @@ gdbtk_file_changed (const char *filename)
>    gdbtk_two_elem_cmd ("gdbtk_tcl_file_changed", filename);
>  }
>  
> -/* Called from exec_file_command */
> +/* Called from exec_file_attach when the executable changes.  PSPACE is
> +   the program space in which the executable was changed.  RELOAD_P is
> +   true if the executable didn't actually change, but instead GDB detected
> +   that the on-disk file change, so reloaded the current executable.  */
>  static void
> -gdbtk_exec_file_display (const char *filename)
> +gdbtk_executable_changed (program_space *pspace, bool reload_p)
>  {
> -  gdbtk_two_elem_cmd ("gdbtk_tcl_exec_file_display", filename);
> +  if (pspace->exec_filename.get () != nullptr)
> +    gdbtk_two_elem_cmd ("gdbtk_tcl_exec_file_display",
> +                        pspace->exec_filename.get ());
>  }
>  
>  /* Called from error_begin, this hook is used to warn the gui
> diff --git a/gdbtk/library/interface.tcl b/gdbtk/library/interface.tcl
> index c69e2f0..da0bcae 100644
> --- a/gdbtk/library/interface.tcl
> +++ b/gdbtk/library/interface.tcl
> @@ -798,7 +798,7 @@ proc gdbtk_tcl_file_changed {filename} {
>  
>  # ------------------------------------------------------------------
>  #  PROCEDURE: gdbtk_tcl_exec_file_display
> -#         This hook is called from exec_file_command. It's purpose
> +#         This hook is called from exec_file_attach. It's purpose
>  #         is to setup the gui for a new file. Note that we cannot
>  #         look for main, since this hook is called BEFORE we
>  #         read symbols. If the user used the "file" command,
>
> base-commit: 0b35bf269b3625d05764ebaeec45b32a2ac03321
> -- 
> 2.25.4