Re: MI -break-info command issues

[Vladimir Prus <ghost@cs.msu.su>]

Eli Zaretskii wrote:

>> Date: Tue, 24 Jan 2006 09:44:49 -0500
>> From: Bob Rossi <bob@brasko.net>
>> Cc: gdb@sources.redhat.com
>> 
>> 2. The output of the command looks like this:
>> > ^done,BreakpointTable={nr_rows="1",nr_cols="6",
>> > hdr=[{width="3",alignment="-1",col_name="number",colhdr="Num"}
>> > {width="14",alignment="-1",col_name="type",colhdr="Type"}
>> > {width="4",alignment="-1",col_name="disp",colhdr="Disp"}
>> > {width="3",alignment="-1",col_name="enabled",colhdr="Enb"}
>> > {width="10",alignment="-1",col_name="addr",colhdr="Address"}
>> > {width="40",alignment="2",col_name="what",colhdr="What"}],
>> > body=[bkpt={number="2",type="breakpoint",disp="keep",enabled="y",
>> > addr="0x08048464",func="main",file="main.cpp",line="6",times="1"}]}
>> > 
>> > What is the point of producing spreadsheet-like output with columns and
>> > column heading and column alignment? I'd expect that any GUI frontend
>> > will have some specific representation and just ignore that extra
>> > formatting. Why generate it at all?
>> 
>> I agree, this output has always been useless to me. I would be happy to
>> see it go away.
> 
> I DON'T agree, and I think it would be a grave mistake to have this
> output go away.  About the worst thing a program can do is have some
> information and not reveal it.  Skipping unneeded information is easy;
> restoring missing one is next to impossible.

Well, let's see what would be missing. The number of rows is trivial to
restore. The number of columns -- well, given that the number of columns
given in above output is 6, while the actual number of fields is something
like 8, I'm not sure what "nr_cols" means at all.

Then, the column names. Any GUI can easily decide where to put each field
and how to name the corresponding GUI item given a list of possible field
names. I don't how it could be useful to know that gdb suggests to give
label "Enb" to the "enabled" field. 

Then, what's "alignment"? Does gdb has a command to set preferred alignment
for fields? If not, then alignment is just GDB's opinion about how GUI
behave, which is not likely to be correct. The width field is completely
redundant -- any GUI toolkit out there that can't auto-resize columns in a
table?

The extra information doesn't pertain to breakpoint itself, it's gdb opinion
on formatting and is hardly usefull for machine interface. IMO, of course.

- Volodya