Re: Status of reported bugs?

[Andreas Zeller]

Hi!

Christoph Koegl <koegl@informatik.uni-kl.de> writes:

> In DDD 3.2 I encounter the following behavior very often: I create
> some displays while debugging some function; I leave the function or
> restart the program and hit some other breakpoint; the displays
> vanish; I reenter the above function.  Every now and then (I have
> not yet been able to see the pattern) the displays do not
> reappear. In the Displays list these displays are labelled
> "deferred", their number has a negative sign. How do I make these
> displays reappear? Why does this happen and when? The shown scope is
> right, so according to the manual the displays should be
> (re-)created.

A display is marked `deferred' if its value cannot be determined at
the current time.  DDD tracks the scope of the displayed variable and
attempts to re-create them as soon as the scope is reached.
This typically happens when restoring a session.

Normally, GDB should redisplay variables as soon as they come into
existence (again).  The `~/.ddd/log' file may contain some diagnostics.


> I have a data display of a struct that contains a char-array of fixed length
> followed by a pointer. Attempting to double-click on the pointer in order to
> pop up a further display results in an error, since the data member labels in
> the box look like this:
> 
> letter                           = 2 '\002'
> inverse                          = "*"
> `\000` <repeats 510 times>, next = 0x2d8878
> 
> but rather should look like this:
> 
> letter  = 2 '\002'
> inverse = "*" '\000' <repeats 510 times>
> next    = 0x2d8878
> 
> Double-clicking on the second line in the original display results in the
> following error message (you know what is coming ;-) ):
> 
> A parse error in expression, near ` <repeats 510 times>, next)'.

If I recall it right, this should be fixed in DDD 3.3 (along with some
other parsing issues).


> I propose the following functionality for DDD:
> 
> Truncation (optional, perhaps with choice of length) of long strings. [...]

This is on the TODO list for future DDD versions.  It may be nice,
though, to have this functionality integrated into GDB, instead - such
that other GDB front-ends may profit as well.  Would you mind
forwarding an appropriate request to the GDB maintainers?


> In the data window I would like to see a popup menu entry "Truncate..." that
> enables the user to truncate the string to the left of some "label = thing"
> display entry.

In DDD 3.3 and later, one could define a special data theme (= a
modifier for data displays) that does this.  See the documentation for
details.


> PS. Another question: One of my applications is 60 MB with debug information.
>     Gdb needs some time to read in the symbols table etc. But with DDD the
>     loading takes three times as long (at least). Why? What kind of initiali-
>     zation takes place within DDD? I just hate waiting 3 Minutes (on a Sparc
>     Ultra 2 with 1G of RAM) for DDD to fire up ... ;-)

No idea on that topic.  Of course, DDD needs some time to do its own
initialization, but there is no reason why this should delay DDD.  Any
ideas (and fixes) are welcome...

Best wishes,

Andreas

-- 
Andreas Zeller     Universitaet Passau
                   http://www.fmi.uni-passau.de/st/staff/zeller/