Re: [dpdk-dev] [PATCH 03/11] mk: fix build dependency of drivers on pmdinfogen

[Thomas Monjalon <thomas.monjalon@6wind.com>]

2016-07-07 11:56, Neil Horman:
> On Thu, Jul 07, 2016 at 05:36:22PM +0200, Thomas Monjalon wrote:
> > When compiling the drivers, some code is generated with pmdinfogen.
> > A fresh parallel build can fail if a driver is compiled before pmdinfogen:
> > 	build/buildtools/dpdk-pmdinfogen: Permission denied
> > 
> > There was a dependency declared in drivers/Makefile but it cannot work
> > because this file is based on mk/rte.subdir.mk which do not handle
> > dependencies.
> > 
> > It is fixed by declaring the whole buildtools as (order only) prerequisite
> > of drivers.
[...]
> > --- a/drivers/Makefile
> > +++ b/drivers/Makefile
> > @@ -34,6 +34,4 @@ include $(RTE_SDK)/mk/rte.vars.mk
> >  DIRS-y += net
> >  DIRS-$(CONFIG_RTE_LIBRTE_CRYPTODEV) += crypto
> >  
> > -DEPDIRS-y += buildtools/pmdinfo
> > -
> >  include $(RTE_SDK)/mk/rte.subdir.mk
> > diff --git a/mk/rte.sdkbuild.mk b/mk/rte.sdkbuild.mk
> > index fb68af2..354f006 100644
> > --- a/mk/rte.sdkbuild.mk
> > +++ b/mk/rte.sdkbuild.mk
> > @@ -49,6 +49,7 @@ $(1): $(sort $(LOCAL_DEPDIRS-$(1)))
> >  endef
> >  
> >  $(foreach d,$(ROOTDIRS-y),$(eval $(call depdirs_rule,$(d))))
> > +drivers: | buildtools
> >  
> I'm not sure i understand the reasoning here, DEPDIRS is meant to declare
> prerequisites to a directory (and its children) getting built, right?  A 
> parallel make should block any drivers getting built prior to pmdinfogen getting
> built.  What am I missing?

DEPDIRS-y is not parsed at all in the context of rte.subdir.mk.
That's why this line was ignored by the build system.