Re: [PATCH 1/2] Always show locations for breakpoints & show canonical location spec

[Lancelot SIX <lsix@lancelotsix.com>]

On Fri, May 20, 2022 at 07:45:09AM +0000, Metzger, Markus T via Gdb-patches wrote:
> Hello Pedro,
> 
> > (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
> 
> This change looks very nice to me.  It will be very helpful once GDB starts
> sliding breakpoints per function and we end up with different source lines
> for different instances.
> 
> I wouldn't indent the breakpoint instances, though.  There is already visual
> feedback in the longer breakpoint numbers and the fact that 'type' and 'disp'
> are omitted to separate the groups.

Hi,

I also find it usefull to have some information about the breakpoint
location as entered by the user.  I think the motivating  examples Pedro
gave give good examples that similar breakpoint locations can come from
quite different user intentions.

As for the indentation, I have to admit I do not really have a strong
opinion.  I am used to the way the things currently are, but this is
probably not the greatest justifications.

Just to experiment with other options, I have a prototype usign a
`tree`-like indentation:

    (gdb) info breakpoints 
    Num        Type           Disp Enb Address            What
    1          breakpoint     keep y                      errors.cc:50
    └─ 1.1                         y   0x000000000224fd06 in internal_error(char const*, int, char const*, ...) at ../../gdbsupport/errors.cc:51
    2          breakpoint     keep y                      internal_error
    └─ 2.1                         y   0x000000000224fd06 in internal_error(char const*, int, char const*, ...) at ../../gdbsupport/errors.cc:51
    3          breakpoint     keep y                      -qualified internal_error
    └─ 3.1                         y   0x000000000224fd06 in internal_error(char const*, int, char const*, ...) at ../../gdbsupport/errors.cc:51
    4          breakpoint     keep y                      error
    ├─ 4.1                         y   0x00000000010b30fe in gcc_c_plugin::error(char const*) const at ../../gdb/../include/gcc-c-fe.def:198
    ├─ 4.2                         y   0x00000000010c6290 in gcc_cp_plugin::error(char const*) const at ../../gdb/../include/gcc-cp-fe.def:983
    └─ 4.3                         y   0x000000000224fbe1 in error(char const*, ...) at ../../gdbsupport/errors.cc:39

I am not sure this is a clear improvement, but I can push the patches
somewhere if someone wants to give it a try.

Best,
Lancelot.