Re: [PATCH 0/2] info breakpoints improvements

[Pedro Alves <pedro@palves.net>]

On 2022-05-20 06:57, Eli Zaretskii wrote:
>> From: Pedro Alves <pedro@palves.net>
>> Date: Thu, 19 May 2022 22:55:50 +0100
>>
>> we get:
>>
>>  (top-gdb) info breakpoints
>>  Num     Type           Disp Enb Address            What
>>  1       breakpoint     keep y                      internal_error
>>   1.1                        y   0x00000000005755a5 in internal_error(char const*, int, char const*, ...) at src/gdb/common/errors.c:54
>>  2       breakpoint     keep y                      -qualified internal_error
>>   2.1                        y   0x00000000005755a5 in internal_error(char const*, int, char const*, ...) at src/gdb/common/errors.c:54
>>  3       breakpoint     keep y                      errors.c:54
>>   3.1                        y   0x00000000005755a5 in internal_error(char const*, int, char const*, ...) at src/gdb/common/errors.c:54
>>   3.2                        y   0x00007ffff6d50410 in PyErr_SetObject at /usr/src/debug/python2-2.7.15-4.fc27.x86_64/Python/errors.c:54
>>  4       breakpoint     keep y                      gdb.c:27
>>   4.1                        y   0x000055555564107b in main(int, char**) at src/gdb/gdb.c:28
>>  (top-gdb)
> 
> I must confess that the new display is much more cluttered, and
> includes redundant information, so it's harder to read.  It also makes
> the important stuff harder to find.  Why exactly is this deemed as
> improvement, and in particular, why would we want this behavior as the
> default?  (I won't mind to have this as opt-in behavior, if someone
> finds this useful in some situations.)

None of the information is actually redundant.  The "Enb" column shows
a different "y", as you can disable a whole breakpoint, or its locations
independently.  The "What" column is showing different things for the breakpoint
and its locations.  I've explained in a lot of detail why I think we want this
in the commit log of patch #1, and now in the reply to your review of patch #1 too.

> 
>> Patch #2 introduces an "info breakpoints -hide-locations" option.
>> With that, you get just the breakpoint header rows, showing the
>> canonical location spec originally used to set the breakpoint, but not
>> what the spec expanded to:
>>
>>  (top-gdb) i b -h
>>  Num     Type           Disp Enb What
>>  1       breakpoint     keep y   internal_error
>>  2       breakpoint     keep y   -qualified internal_error
>>  3       breakpoint     keep y   errors.c:54
> 
> If we want a concise display that only shows the important parts, I'd
> lose the "Disp" column.

I'm not sure how you're determining "important".  That'd make it impossible to
distinguish a "break" from a "tbreak".  I'm only after hiding the breakpoint locations.
I.e., I want to still see all information about each of the breakpoints, just not
its resolved locations.   I only made -hide-locations skip the "Address" column because it
would always be empty otherwise.  For example, here I set a tbreak, and I have a
silent breakpoint:

 (top-gdb) info breakpoints -h
 Num     Type           Disp Enb What
 1       breakpoint     keep y   internal_error
 2       breakpoint     keep y   info_command
         silent
         return
 3       breakpoint     keep y   main
         breakpoint already hit 1 time
 4       breakpoint     del  y   get_selected_frame
         stop only if debug_infrun > 0

So, a more concise display may be interesting, but I'd like to think of it as
a separate feature.