Re: separate the notions of always-build and jobserver

[Ralf Wildenhues]

http://thread.gmane.org/gmane.comp.gnu.make.bugs/5015

* Ralf Wildenhues wrote on Tue, Sep 28, 2010 at 10:55:48PM CEST:
> Currently, 'make -n' only executes recipe commands prefixed with '+' or
> containing one of the strings ${MAKE} or $(MAKE).  Likewise, parallel
> make hands the jobserver file descriptors only to rules annotated in the
> same way.
> 
> It would be nice if these two semantics could be decoupled.

FYI, to follow up to this old message myself, according to the other
message I just sent, I intend to use the following for this:

> 1) The GCC LTO (link-time optimization) engine may exploit
> parallelization during whole-program linking by hooking into the job
> server: http://gcc.gnu.org/ml/gcc-patches/2010-08/msg02149.html

in Automake:

am__if_make_flag = \
$(if $(strip $(foreach flag,$(filter-out --%,$(MAKEFLAGS)),$(if \
  $(findstring =,$(flag)),,$(if \
    $(findstring $(1),$(flag)),:)))),$(2),$(3))
LTOPAR = $(call am__if_make_flag,n,,+)

and prefix link recipe commands with $(LTOPAR) (if GNU make is used).

Cheers,
Ralf