Re: [RFC/PATCH] Clean up unused variables (and prepare for `-Wunused-variable' flag)

[Sergio Durigan Junior <sergiodj at redhat dot com>]

On Tuesday, April 24 2012, Pedro Alves wrote:

> Hi SÃrgio,
>
> First off, thanks for doing this.

Thanks for reviewing.

> On 04/23/2012 11:51 PM, Sergio Durigan Junior wrote:
>
>> Hi,
>> 
>> This patch is a followup of the discussion in:
>> 
>>     http://sourceware.org/ml/gdb/2012-04/msg00171.html> 
>> First of all, I am sorry for the size of this patch, but I couldn't
>> think of a good way of splitting it, and also I thought it would be
>> useless since these changes are all logically related.
>
>
> It's not useless at all.  This warning points at two classes of problems:
>
>  - variables that are no longer necessary, and can be garbage collected.
>  - variables that actually should be being used, but they're not due to
>    some latent bug.
>
> I skimmed the patch, and noted several places, mostly in tdep code, where
> you end up removing more than the unsuspecting auxiliary and obviously-left-
> -behind-by-accident variable.  Some of those removed bits could well be latent
> bugs.  Some hunks seem to remove used variables and expand what they were
> initialized from at the used sites.  What's up with that?  Please give rationale
> for any change that requires more than idle brain power to understand.
> :-)

We already talked on IRC, but I'm replying this message for the sake of
keep the record.  As I said, initially I thought that those
initialized-but-not-used cases were copy-and-paste mistakes.  But thanks
for pointing that.  Here's what I'm going to do:

- Split these cases by arch, and resubmit it so that the maintainers of
  each arch will get a chance to review and see if the case is a latent
  bug or not

- Split and commit the obvious bits, as approved by Tromey and you in
  the other message in this thread.

>> I'd like to apply it, but I have a couple of questions before:
>> 
>> a) How's the ChangeLog for this patch supposed to be?  Can I make a
>> "generic" ChangeLog, saying something like `Remove unused variables from
>> files'?
>> 
>> b) I'd like someone to take a look at the `observer.sh' change, please.
>
>
> Please sent it as a separate patch, along with a rationale.
> Also, the .c files under features/ are generated files.  We'll need to fix
> the generator instead, again, best done as a separate patch.

Thanks, I totally forgot about this fact!  And I can't believe I didn't
read the header comment on the top of those files :-).  Anyway, this
change will go as a separate patch as well.

-- 
Sergio