[PATCH util/macros] Drop -fno-strict-aliasing from XORG_CWARNFLAGS

[Michel Dänzer]

On 2017-12-13 08:47 PM, Adam Jackson wrote:
> On Wed, 2017-12-13 at 11:31 -0800, Keith Packard wrote:
>> Adam Jackson <ajax at redhat.com> writes:
>>
>>> This has been "deprecated" since 2011, but because it is still
>>> referenced from XORG_DEFAULT_OPTIONS nothing has ever been updated to
>>> get strict aliasing right. Let's fix that.
>>
>> I don't understand this -- are you getting rid of this option from our
>> compiles or not?
> 
> I mean, the lines in the diff start with "-".  "Let's fix that" here
> means "let's build normally and see what falls out".
> 
>> I can assure you that our code is unlikely to work with
>> out it.
> 
> xserver still passes make check when built without it. Well, the meson
> build does anyway, I haven't gotten around to trying it with the
> autotools build yet, nor adding -Werror=strict-aliasing and rebuilding
> the world, but that would obviously be prerequisite for releasing a
> version of util-macros with this change in it.

I don't think compilers can reliably warn about all strict aliasing
violations yet (ever?).

Is this really worth the risk? Do you have any numbers showing tangible
benefits of this change?


-- 
Earthling Michel Dänzer               |               http://www.amd.com
Libre software enthusiast             |             Mesa and X developer