Re: [Patch] PR55189 enable -Wreturn-type by default

[Sylvestre Ledru <sylvestre@debian.org>]

On 17/06/2014 19:15, Joseph S. Myers wrote:
> On Tue, 17 Jun 2014, Sylvestre Ledru wrote:
>
>> On 05/06/2014 20:01, Joseph S. Myers wrote:
>>>> Initially, I implemented -Wmissing-return to manage this case (
>>>> https://gcc.gnu.org/ml/gcc-patches/2014-01/msg00820.html ) but Jason
>>>> suggested to remove that:
>>>> https://gcc.gnu.org/ml/gcc-patches/2014-01/msg01033.html
>>>> (I don't have a strong opinion on the subject).
>>> I think splitting the option like that makes sense.  Compatibility 
>>> indicates that -Wreturn-type and -Wall should still enable 
>>> -Wmissing-return, but only the other pieces of -Wreturn-type should be 
>>> enabled by default, at least for C.  (Enabling -Wimplicit-int by default 
>>> might be a good starting point.)
>> OK.
>> As attachment, you will find a potential implementation. Is that what
>> you expect?
> It would help a lot if it included testcases for what various options / 
> option combinations do / do not enable.  
OK. I will do that.
We should test the following:
* default => run just -Wreturn-type
* -Wreturn-type => Run both
* -Wreturn-type + -Wmissing-return => Run both
* -Wno-return-type + -Wmissing-return => Run just the second one
* -Wno-return-type + -Wno-missing-return => Run none
Do you see any other?
> I expect that each option 
> continues to enable the warnings it does at present (so if a user 
> explicitly does -Wreturn-type it also enables the -Wmissing-return 
> warnings, for example) - but some warnings would start to be enabled by 
> default.  If someone does e.g. -Wno-implicit that would disable the 
> default -Wimplicit-int; if they do -Wno-implicit -Wimplicit that would 
> have the same effect as just -Wimplicit (so keeping the default warnings 
> enabled, and possibly enabling others).
>
OK. I will try to implement that later (I don't think -Wimplicit-int is
necessary to enable -Wreturn-type by default).
Besides that, are you OK with my changes? (with the tests updated)

Thanks,
Sylvestre