[Development] Enabling -Werror developer builds

[Alan Alpert]

On Mon, Aug 19, 2013 at 4:47 PM, Thiago Macieira
<thiago.macieira at intel.com> wrote:
> On segunda-feira, 19 de agosto de 2013 15:40:06, Alan Alpert wrote:
>> > 2) -Werror is enabled only for certain compiler versions. I'll update the
>> > whitelist to have an upper range too. For example, right now it enables -
>> > Werror for GCC 4.6 and above. I'm going to introduce an upper limit
>> > because we don't know what new warnings our code triggers with newer
>> > versions of GCC. That means we'll need to first clean up the warnings
>> > before expanding the whitelist.
>>
>> How is this "clean up" to be managed? The scenario I'm envisioning is
>> that warnings are cleaned up inside qtbase, allowing the change to
>> pass CI, while a new warning appears in another module which is then
>> broken by the qtbase change. We might need to integrate qt5.git
>> merging into the whitelist expansion test somehow, or provide another
>> solution so that all modules are checked before updating the
>> whitelist.
>
> Someone or a group of people fixes all the warnings with a given new compiler
> version in all modules. Once all changes are in, past the CI and possibly past
> a qt5.git integration, we expand the whitelist in qtbase.
>
> Worst case scenario, there's a race condition with new code that introduces a
> new warning.

Given how long CI integrations can take I would not be surprised to
see such a race condition occur. But so long as "all modules" is
explicitly in the process (and we can't think of a good automated test
for it) I can accept that risk.

--
Alan Alpert