Implement 'set print frame-info|frame-arguments presence'.

New settings allow to better control what frame information is printed.

'set print frame-info' allows to override the default frame information
printed when a GDB command prints a frame.
The backtrace command has a new option -frame-info to override
this global setting.

It is now possible to have very short frame information by using the
new 'set print frame-arguments presence' and
'set print frame-info short-location'.

Combined with 'set print address off', a backtrace will only show
the essential information to see the function call chain, e.g.:
  (gdb) set print address off
  (gdb) set print frame-arguments presence
  (gdb) set print frame-info short-location
  (gdb) bt
  #0  break_me ()
  #1  call_me (...)
  #2  main ()
  (gdb)

This is handy in particular for big backtraces with functions having
many arguments.

Python frame filter printing logic has been updated to respect the new
setting in non MI mode.

Also, the default frame information printed was inconsistent when
backtrace was printing the frame information itself, or when the python
frame filtering code was printing the frame information.
This patch changes the default of python frame filtering to have a
consistent behaviour regarding printed frame-information, whatever
the presence/activity/matches of python filters.

2019-07-29  Philippe Waroquiers  <philippe.waroquiers@skynet.be>

	* frame.h (enum print_what): New value 'SHORT_LOCATION', update
	comments.
	(print_frame_info_auto, print_frame_info_source_line,
	print_frame_info_location, print_frame_info_source_and_location,
	print_frame_info_location_and_address, print_frame_info_short_location):
	New declarations.
	(struct frame_print_options): New member print_frame_info.
	* extension.h (enum ext_lang_frame_args): New value CLI_PRESENCE.
	* stack.h (get_user_print_what_frame_info): New declaration.
	(frame_show_address): New declaration.
	* stack.c (print_frame_arguments_choices): New value 'presence'.
	(print_frame_info_auto, print_frame_info_source_line,
	print_frame_info_location, print_frame_info_source_and_location,
	print_frame_info_location_and_address, print_frame_info_short_location,
	print_frame_info_choices, print_frame_info_print_what): New definitions.
	(print_frame_args): Only print dots for args if print frame-arguments
	is 'presence'.
	(frame_print_option_defs): New element for "frame-info".
	(get_user_print_what_frame_info): New function.
	(frame_show_address): Make non static.  Move comment to stack.h.
	(print_frame_info_to_print_what): New function.
	(print_frame_info): Update comment.  Use fp_opts.print_frame_info
	to decide what to print.
	(backtrace_command_1): Handle the new print_frame_arguments_presence
	value.
	(_initialize_stack): Call add_setshow_enum_cmd for frame-info.
	* python/py-framefilter.c (py_print_args): Handle CLI_PRESENCE.
	(py_print_frame): In non-mi mode, use LOCATION as default for
	print_what, similarly to frame information printed directly by
	backtrace command. Handle frame-info user option in non MI mode.

1 files changed, 4 insertions, 1 deletions

diff --git a/gdb/extension.h b/gdb/extension.h
index 5e914f5..581afc2 100644
--- a/gdb/extension.h
+++ b/gdb/extension.h
@@ -125,7 +125,10 @@ enum ext_lang_frame_args
     CLI_SCALAR_VALUES,
 
     /* Print all values for arguments when invoked from the CLI. */
-    CLI_ALL_VALUES
+    CLI_ALL_VALUES,
+
+    /* Only indicate the presence of arguments when invoked from the CLI.  */
+    CLI_PRESENCE
   };
 
 /* The possible results of