[PATCH util-macros 1/2] Don't disable strict aliasing (-fno-strict-aliasing) globally

[Jeremy Huddleston]

On Oct 31, 2010, at 18:39, Gaetan Nadon wrote:

> On Sun, 2010-10-31 at 15:54 -0700, Jeremy Huddleston wrote:
> 
>> Resurrecting this thread as I just realized it was never actually
>> fixed.
>> 
>> I propose we actually follow up on these changes.  We should remove
>> -fno-strict-aliasing from XORG_CWARNFLAGS and only add them to the
>> modules that actually require it.  We can start out consercatively by
>> adding it to the modules listed in the email below (as well as the
>> xf86-* drivers that historically had the flag which I didn't check at
>> the time of the first email... I know intel needs it)
>> 
>> 
> 
> I recall the difficulty of maintain backward compatibility. For example,
> previous versions of libICE would not produce the same object code when
> configured against the latest util-macros which would no longer have
> -fno-strict-aliasing.

Correct.  They would produce what we intend to ship rather that what we accidentally shipped.

> 
> The only way (I think) to resolve the situation is to create two new
> variables, one for the real warning flags and one for the aliasing flag.
> The new warning variable replaces the CWARNFLAGS in the 166 places where
> it is used. The new aliasing variable would be added where it is needed.
> 
> I had pushed a good number of patches to clean-up CWARNFLAGS usage as it
> was abused in several Makefiles. I recall having compiled a list of
> modules that would need the aliasing flag, it might be on xorg-devel.
> 
> The timing, just after a new release, seems to be appropriate to engage
> into such an endeavor.

Ok.