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Re: [PATCH/RFA] Introduce new $_isvoid() convenience function
- From: Doug Evans <dje at google dot com>
- To: Sergio Durigan Junior <sergiodj at redhat dot com>
- Cc: GDB Patches <gdb-patches at sourceware dot org>
- Date: Thu, 12 Sep 2013 16:59:56 -0700
- Subject: Re: [PATCH/RFA] Introduce new $_isvoid() convenience function
- Authentication-results: sourceware.org; auth=none
- References: <m3a9jh6bs0 dot fsf at redhat dot com>
On Thu, Sep 12, 2013 at 1:11 PM, Sergio Durigan Junior
<sergiodj@redhat.com> wrote:
> gdb/
> 2013-09-12 Sergio Durigan Junior <sergiodj@redhat.com>
>
> * NEWS: Mention new convenience function $_isvoid.
> * value.c (isvoid_internal_fn): New function.
> (_initialize_values): Add new convenience function $_isvoid.
>
> gdb/doc/
> 2013-09-12 Sergio Durigan Junior <sergiodj@redhat.com>
>
> * gdb.texinfo (Convenience Functions): Mention new convenience
> function $_isvoid.
>
> gdb/testsuite/
> 2013-09-12 Sergio Durigan Junior <sergiodj@redhat.com>
>
> * gdb.base/gdbvars.exp (test_convenience_functions): New
> function. Call it.
Hi. Thanks for persevering!
While I often follow "it's easier to relax restrictions than impose
them after the fact",
in this case I wonder if there's any reason to restrict $_isvoid() to
convenience variables.
Thoughts?
For "void foo(){}", is there any real difference to:
(gdb) set $foo = foo()
(gdb) p $_isvoid($foo)
(gdb) p $_isvoid(foo())
[Haven't tried it, but I'm guessing removing the internalva4 check in
your patch would make that work.]
Also, you've put a fair bit of time into this, and I'm happy with
what you've got. And thanks!
The high order bit here for me is being able to script $_exitcode + $exitsignal.
If we're going with checking for a void value, one could just leave it
to be handled in Python.
OTOH, this patch is really simple, and IMO it is *nice* to be able to
do this from just a plain gdb script,
so I'm advocating accepting this patch (modulo maybe handling any void
value, not just conv vars).
btw, I noticed that if I run a program to exit, and then rerun to
main, $_exitcode has the last exit code - I would have expected it to
get reset to void upon rerun. After all, if I stop at main the first
time through, $_exitcode is void.
[I'll file a bug, no need to address this in your patch series.]