Re: order-only prerequisites don't behave as I'd have expected after reading the documentation

[Stefano Lattarini]

On 06/12/2012 02:06 AM, Philip Guenther wrote:
> On Mon, Jun 11, 2012 at 12:53 PM, Stefano Lattarini
> <address@hidden> wrote:
> ...
>> I was hoping to be able to the order-only prerequisites to enforce ordering
>> between .PHONY targets.  At this point, I guess I should state the problem
>> I am trying to solve rather than just the attempts I've made at solving it.
>>
>>   Is there an easy, scalable way to specify in a GNUmakefile that, whenever
>>   two given targets T1 and T2 (either phony or not) are to be updated, T1's
>>   recipe must be executed before T2's, all without declaring any dependency
>>   of T2 on T1?  So that for example, assuming T1 and T2 are both phony:
>>
>>     $ make T1 # Only run T1's recipe
>>     $ make T1 # Only run T2's recipe
> 
> (I think you meant "make T2" there...)
>
Yes, sorry.

> 
>>     $ make T2 T1 # Run T1's recipe, then T2's recipe
>>     $ make -j8 T2 T1 # Again, run T1's recipe, then T2's recipe
> 
> I think I would use a test on $(MAKECMDGOALS) to make T1 a
> prerequisite of T2 if and only if T1 is a goal, say...
> 
>      ifneq ($(filter T1,${MAKECMDGOALS}),)
>      T2: T1
>      endif
>
Not good enough; the "order dependency" I want between T1 and T2 should
have to work also when they are updated as dependencies of other targets:

    $ cat Makefile
    all: T1 T2
    ...
    $ make all # Ought to work executing T1 before T2.

Regards,
  Stefano