Re: [RFC] Show the selected frame in "bt"

[Simon Marchi <simark@simark.ca>]

On 5/29/26 2:45 PM, Tom Tromey wrote:
> I've occasionally wished that "bt" would indicate the selected frame.
> This patch implements this idea.  In particular it marks the selected
> frame with "*", similar to other "selected" output in gdb.  (See that
> other series where emoji were allowed in the "current" column of a
> table; if that is ever resurrected, I'd expect the same treatment to
> be applied here.)
> 
> Now the output looks like:
> 
> (gdb) bt
>   #0  0x00007ffff6e381fd in poll () from /lib64/libc.so.6
>   #1  0x000000000100b1ee in gdb_wait_for_event (block=1) at ../../binutils-gdb/gdbsupport/event-loop.cc:587
>   #2  0x000000000100a77f in gdb_do_one_event (mstimeout=-1) at ../../binutils-gdb/gdbsupport/event-loop.cc:263
> * #3  0x00000000007d2c6a in interp::do_one_event (this=<optimized out>, mstimeout=-1) at ../../binutils-gdb/gdb/interps.h:90
>   #4  start_event_loop () at ../../binutils-gdb/gdb/main.c:400
>   #5  captured_command_loop () at ../../binutils-gdb/gdb/main.c:465
>   #6  0x00000000007d5715 in captured_main (context=context@entry=0x7fffffffdd10) at ../../binutils-gdb/gdb/main.c:1373
>   #7  gdb_main (args=args@entry=0x7fffffffdd50) at ../../binutils-gdb/gdb/main.c:1392
>   #8  0x0000000000452cd5 in main (argc=1, argv=0x7fffffffdea8) at ../../binutils-gdb/gdb/gdb.c:38
> 
> I think the main downside of this patch is that it uses a little more
> horizontal space for the indicator.

I like it, it fits well in the "show user what is selected" paradigm.

If we're talking about bt formatting and horizontal space, we could
consider not showing addresses by default, I bet that most users don't
care.  I find it ugly that by default the address is shown for some
frames but not all, it makes things unaligned (you can force GDB to show
addresses with `-frame-info location-and-address` though).  I don't know
if there is currently a setting to make GDB show the function name but
not the address.

Simon