[PATCH] Mark linker Makefile rules for job server build

[Paolo Bonzini]

On 10/04/2010 07:42 PM, Ralf Wildenhues wrote:
> Hello,
>
> * Andi Kleen wrote on Mon, Oct 04, 2010 at 03:11:39PM CEST:
>> -fwhopr=jobserver requires telling GNU make that the linker (= lto)
>> rules support job server, so that the necessary jobserver
>> information is passed through.
>>
>> Add + to all the executable targets that run LTO for this purpose.
>
> FWIW, this will break 'make -n'.  I sent a feature request for GNU make:
> <http://thread.gmane.org/gmane.comp.gnu.make.bugs/5015>
>
> With GNU make-specific code, we could probably work around it.  I'm
> thinking of something along these lines:
>
> jobserv := $(shell dry=no; for f in $(MAKEFLAGS); do \
>                  case $$f in \
>                    (*=*|--*);; \

Any reason to check for *=*?  Even -W or -I do not appear there.  I 
always thought this would do:

ifeq (n,$(findstring n, $(filter-out --%, $(MAKEFLAGS))))
$(warning dry-run)
else
$(warning not dry-run)
endif

(BTW, adding --no-print-directory to $(MAKEFLAGS) broke GNU make's own 
example of using findstring to test MAKEFLAGS...).

Paolo