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, 28 insertions, 9 deletions

diff --git a/gdb/frame.h b/gdb/frame.h
index a79eeee..ccc2850 100644
--- a/gdb/frame.h
+++ b/gdb/frame.h
@@ -677,18 +677,28 @@ extern struct gdbarch *frame_unwind_arch (frame_info *next_frame);
 extern struct gdbarch *frame_unwind_caller_arch (struct frame_info *frame);
 
 
-/* Values for the source flag to be used in print_frame_info_base().  */
+/* Values for the source flag to be used in print_frame_info ().
+   For all the cases below, the address is never printed if
+   'set print address' is off.  When 'set print address' is on,
+   the address is printed if the program counter is not at the
+   beginning of the source line of the frame
+   and PRINT_WHAT is != LOC_AND_ADDRESS.  */
 enum print_what
-  { 
-    /* Print only the source line, like in stepi.  */
-    SRC_LINE = -1, 
-    /* Print only the location, i.e. level, address (sometimes)
-       function, args, file, line, line num.  */
+  {
+    /* Print only the address, source line, like in stepi.  */
+    SRC_LINE = -1,
+    /* Print only the location, i.e. level, address,
+       function, args (as controlled by 'set print frame-arguments'),
+       file, line, line num.  */
     LOCATION,
     /* Print both of the above.  */
-    SRC_AND_LOC, 
-    /* Print location only, but always include the address.  */
-    LOC_AND_ADDRESS 
+    SRC_AND_LOC,
+    /* Print location only, print the address even if the program counter
+       is at the beginning of the source line.  */
+    LOC_AND_ADDRESS,
+    /* Print only level and function,
+       i.e. location only, without address, file, line, line num.  */
+    SHORT_LOCATION
   };
 
 /* Allocate zero initialized memory from the frame cache obstack.
@@ -772,6 +782,14 @@ extern const char print_frame_arguments_all[];
 extern const char print_frame_arguments_scalars[];
 extern const char print_frame_arguments_none[];
 
+/* The possible choices of "set print frame-info".  */
+extern const char print_frame_info_auto[];
+extern const char print_frame_info_source_line[];
+extern const char print_frame_info_location[];
+extern const char print_frame_info_source_and_location[];
+extern const char print_frame_info_location_and_address[];
+extern const char print_frame_info_short_location[];
+
 /* The possible choices of "set print entry-values".  */
 extern const char print_entry_values_no[];
 extern const char print_entry_values_only[];
@@ -787,6 +805,7 @@ extern const char print_entry_values_default[];
 struct frame_print_options
 {
   const char *print_frame_arguments = print_frame_arguments_scalars;
+  const char *print_frame_info = print_frame_info_auto;
   const char *print_entry_values = print_entry_values_default;
 
   /* If non-zero, don't invoke pretty-printers for frame