Re: [RFC] Update minimum make version to 3.81

["Paul E. Murphy" <murphyp at linux dot vnet dot ibm dot com>]

On 06/24/2016 11:31 AM, Florian Weimer wrote:
> On 06/24/2016 06:10 PM, Mike Frysinger wrote:
>> On 24 Jun 2016 13:24, Florian Weimer wrote:
>>> On 06/11/2016 12:27 AM, Roland McGrath wrote:
>>>> eval is a pretty horrible feature and I'd probably object to introducing
>>>> any uses of it into libc's makefiles.  We already have lots of things that
>>>> might have been done that way, but are instead done with generated makefiles.
>>>
>>> I would like to put this into malloc/Makefile:
>>>
>>> $(foreach t,$(tests),$(eval CFLAGS-$t.c += -DTEST_NO_MALLOPT))
>>>
>>> What's the alternative for adding a -D flag to every test compilation in
>>> a subdirectory?
>>
>> maybe something like (untested):
>> CPPFLAGS += $(if $(filter $(@F),$(tests)),-DTEST_NO_MALLOPT)
> 
> Hmm, right.  It's relying on the delayed expansion.  Not sure how this is less evil, though.  It also has at least quadratic run-time behavior.
> 
> Thanks,
> Florian
> 

That seems like an undesirable precedent to set.
What about target specific variable updates on
the object files?

I attempted a similar thing in my current set
of patches to libm.

i.e (also untested):

$(foreach,s,$(all-object-suffixes),$(addsuffix,$(s),$(tests))): CPPFLAGS += -DTEST_NO_MALLOPT

IMO, eval still seems like the least bad option.