Compilation errors on Ubuntu 8.10 Intrepid Ibex

Maxim Dounin mdounin at
Tue Nov 11 02:48:14 MSK 2008


On Tue, Nov 11, 2008 at 12:43:54AM +0300, Igor Sysoev wrote:

> On Tue, Nov 11, 2008 at 12:35:40AM +0300, Maxim Dounin wrote:


> > More details here:
> > 
> >
> > 
> > However I don't think it's a good idea to use stub variables.  
> > Probably something like
> > 
> >     if (ngx_write_fd(...) == NGX_FILE_ERROR) {
> >         /* void */
> >     }
> > 
> > would be better.
> > 
> > Maxim Dounin
> > 
> > p.s. Actually I think that it's glibc's bug.  But we probably have 
> > to live with it, at least for some time.
> I believe this is gcc bug because I explictly says that I do not need
> the function result using (void) case.

It can't be gcc bug - warn_unused_result was explicitly coded to 
produce warning unavoidable by (void) cast.  I agree that it's 
a misfeature though.

Anyway, there are many handwaving about this at the url I posted 
(and in other places as well).  I don't think we want to repeat it 
here.  :)

> Dummy result checking as well as stub variable are security/reliabilty
> profanation.

With [dummy] result checking we have some good place where we can 
write reason why we can't do anything with the result,
so it looks better for me than stub variable.  Of course both 
aren't ideal.

> The (void) cast should be compact way to do the same.

It should, but it isn't.  The question now is how to live with it 
with minimal impact on decent systems.  Probably the best solution 
would be just to omit -Werror on such systems.

Maxim Dounin

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