Re: failure to build due to ignoring fwrite() result

[Eric Blake]

On 08/30/2010 02:48 PM, Paul Eggert wrote:
> On 08/30/10 12:52, Jim Meyering wrote:
> > However, for the vast majority of the functions marked with this
> > attribute, ignoring the return value really is a bug in all but a
> > very small fraction of the use cases.
>
> That may well be, but that's not the issue.  The issue is whether
> the cost of using -Wunused-result exceeds its benefits.  The cost
> accrues in the cases where it's not a bug to ignore
> the returned value, possibly because it's a function like
> fwrite or strtod that should never have been marked with
> __attribute__ ((__warn_unused_result__)).  The benefit accrues
> in the cases where using -Wunused-result catches significant bugs
> that would not be caught otherwise.

Which takes us back to the argument that if a function is poorly marked, 
it should be easy to override that poor marking, so that the rest of the 
code using that function does not have to mark it with ignore_value, 
while not crippling the remaining functions where it makes sense.

I'm leaning even more heavily towards a patch to gnulib's stdio.in.h 
that undoes the poor glibc marking on fwrite.

--
Eric Blake   address@hidden    +1-801-349-2682
Libvirt virtualization library http://libvirt.org