Re: [dpdk-dev] [PATCH] Pass CC option when building kernel modules

[Bruce Richardson <bruce.richardson@intel.com>]

On Wed, Oct 08, 2014 at 07:15:04PM +0200, Thomas Monjalon wrote:
> 2014-10-06 16:57, Sergio Gonzalez Monroy:
> > At least on kernels 3.15 or newer, DPDK build is broken for CLANG target.
> > The issue is that the kernel build system sets the flags before including
> > DPDK makefile and therefore assumes the incorrect compiler.
> > 
> > Signed-off-by: Sergio Gonzalez Monroy <sergio.gonzalez.monroy@intel.com>
> 
> > --- a/mk/rte.module.mk
> > +++ b/mk/rte.module.mk
> > @@ -78,7 +78,7 @@ build: _postbuild
> >  $(MODULE).ko: $(SRCS_LINKS)
> >  	@if [ ! -f $(notdir Makefile) ]; then ln -nfs $(SRCDIR)/Makefile . ; fi
> >  	@$(MAKE) -C $(RTE_KERNELDIR) M=$(CURDIR) O=$(RTE_KERNELDIR) \
> > -		CROSS_COMPILE=$(CROSS)
> > +		CC=$(KERNELCC) CROSS_COMPILE=$(CROSS)
> 
> > --- a/mk/target/generic/rte.vars.mk
> > +++ b/mk/target/generic/rte.vars.mk
> > @@ -149,4 +149,6 @@ endif
> >  export CFLAGS
> >  export LDFLAGS
> >  
> > +else # ! ifeq ($(KERNELRELEASE),)
> > +CC = $(KERNELCC)
> >  endif
> 
> Why is it needed here? Setting CC in rte.module.mk is not sufficient?
> 
Right now, no it's not, and that's what is causing the error. However, we 
maybe can look and see if we moved the definition in rte.module.mk we might 
get the same effect.

/Bruce

> Thanks
> -- 
> Thomas