Re: Pattern rule executed multiple times with multiple jobs

[Kevin Locke]

Hi Philip,

Thank you very much for the response and explanation, that explains a lot.

On 08/09/2014 04:15 PM, Philip Guenther wrote:
> On Sat, Aug 9, 2014 at 2:24 PM, Kevin Locke <address@hidden 
> <mailto:address@hidden>> wrote:
>
>     [...]
>
>     For example, consider the following Makefile:
>
>     all: foo1 foo2
>
>     foo%:
>             sleep 2
>             touch foo1 foo2
>
> ...
>
>     Demonstrating that the recipe is executed twice, once for each target.
>     Is this the expected behavior?  Am I misinterpreting the sentence from
>     the manual?
>
>
> Yep.  That pattern rule only has a single target "foo%", not multiple 
> targets.  An example of the latter can be found a little further down 
> in the manual:

Ah yes, you are correct, I was misinterpreting what a "target" is. I had 
assumed it was the thing which is matched against the pattern in the 
rule rather than the pattern itself.  My mistake.

>      Is there any way to specify that the rule should be run
>     once to make both files, even when running with multiple jobs, without
>     resorting to one of the hacks in the oft-cited CMCrossroads article on
>     Rules with Multiple Outputs in GNU Make[2]?
>
> An example closer to yours would be
>
> %1 %2:
>         sleep 2
>         touch $*1 $*2
>
> $ make -j3 foo1 foo2
> sleep 1
> touch foo1 foo2
> make: Nothing to be done for 'foo2'.
> $

Thanks, that works for me.  It's not quite so simple in the makefile 
which provoked the question, but I was able to create a pattern for each 
generated file through some function calls and it seems to be working well.

Thanks again,
Kevin