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

Message ID	1412611022-8278-1-git-send-email-sergio.gonzalez.monroy@intel.com (mailing list archive)
State	Superseded, archived
Headers	From: Sergio Gonzalez Monroy <sergio.gonzalez.monroy@intel.com> To: dev@dpdk.org Date: Mon, 6 Oct 2014 16:57:02 +0100 Message-Id: <1412611022-8278-1-git-send-email-sergio.gonzalez.monroy@intel.com> Subject: [dpdk-dev] [PATCH] Pass CC option when building kernel modules Precedence: list Errors-To: dev-bounces@dpdk.org Sender: "dev" <dev-bounces@dpdk.org>

Message ID

1412611022-8278-1-git-send-email-sergio.gonzalez.monroy@intel.com (mailing list archive)

State

Superseded, archived

Headers

From: Sergio Gonzalez Monroy <sergio.gonzalez.monroy@intel.com>
To: dev@dpdk.org
Date: Mon,  6 Oct 2014 16:57:02 +0100
Message-Id: <1412611022-8278-1-git-send-email-sergio.gonzalez.monroy@intel.com>
Subject: [dpdk-dev] [PATCH] Pass CC option when building kernel modules
Precedence: list
Errors-To: dev-bounces@dpdk.org
Sender: "dev" <dev-bounces@dpdk.org>

Commit Message

Sergio Gonzalez Monroy Oct. 6, 2014, 3:57 p.m. UTC

  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>
---
 mk/rte.module.mk               | 2 +-
 mk/target/generic/rte.vars.mk  | 2 ++
 mk/toolchain/clang/rte.vars.mk | 5 +----
 mk/toolchain/gcc/rte.vars.mk   | 1 +
 mk/toolchain/icc/rte.vars.mk   | 5 +----
 5 files changed, 6 insertions(+), 9 deletions(-)

Comments

Bruce Richardson Oct. 6, 2014, 4:12 p.m. UTC | #1

On Mon, Oct 06, 2014 at 04:57:02PM +0100, Sergio Gonzalez Monroy wrote:
> 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>

I can confirm that this patch fixes the clang compile for me on Fedora 20 
with kernel 3.16.3-200.fc20.x86_64.

Acked-by: Bruce Richardson <bruce.richardson@intel.com>

> ---
>  mk/rte.module.mk               | 2 +-
>  mk/target/generic/rte.vars.mk  | 2 ++
>  mk/toolchain/clang/rte.vars.mk | 5 +----
>  mk/toolchain/gcc/rte.vars.mk   | 1 +
>  mk/toolchain/icc/rte.vars.mk   | 5 +----
>  5 files changed, 6 insertions(+), 9 deletions(-)
> 
> diff --git a/mk/rte.module.mk b/mk/rte.module.mk
> index c4ca3fd..41c0d0f 100644
> --- 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)
>  
>  # install module in $(RTE_OUTPUT)/kmod
>  $(RTE_OUTPUT)/kmod/$(MODULE).ko: $(MODULE).ko
> diff --git a/mk/target/generic/rte.vars.mk b/mk/target/generic/rte.vars.mk
> index 6020f20..74ff771 100644
> --- a/mk/target/generic/rte.vars.mk
> +++ b/mk/target/generic/rte.vars.mk
> @@ -149,4 +149,6 @@ endif
>  export CFLAGS
>  export LDFLAGS
>  
> +else # ! ifeq ($(KERNELRELEASE),)
> +CC = $(KERNELCC)
>  endif
> diff --git a/mk/toolchain/clang/rte.vars.mk b/mk/toolchain/clang/rte.vars.mk
> index ee4f451..40cb389 100644
> --- a/mk/toolchain/clang/rte.vars.mk
> +++ b/mk/toolchain/clang/rte.vars.mk
> @@ -38,11 +38,8 @@
>  #   - define TOOLCHAIN_ASFLAGS variable (overriden by cmdline value)
>  #
>  
> -ifeq ($(KERNELRELEASE),)
>  CC        = $(CROSS)clang
> -else
> -CC        = $(CROSS)gcc
> -endif
> +KERNELCC  = $(CROSS)gcc
>  CPP       = $(CROSS)cpp
>  # for now, we don't use as but nasm.
>  # AS      = $(CROSS)as
> diff --git a/mk/toolchain/gcc/rte.vars.mk b/mk/toolchain/gcc/rte.vars.mk
> index 262ebdf..993eb26 100644
> --- a/mk/toolchain/gcc/rte.vars.mk
> +++ b/mk/toolchain/gcc/rte.vars.mk
> @@ -39,6 +39,7 @@
>  #
>  
>  CC        = $(CROSS)gcc
> +KERNELCC  = $(CROSS)gcc
>  CPP       = $(CROSS)cpp
>  # for now, we don't use as but nasm.
>  # AS      = $(CROSS)as
> diff --git a/mk/toolchain/icc/rte.vars.mk b/mk/toolchain/icc/rte.vars.mk
> index 612370d..f03a2a2 100644
> --- a/mk/toolchain/icc/rte.vars.mk
> +++ b/mk/toolchain/icc/rte.vars.mk
> @@ -41,11 +41,8 @@
>  # Warning: we do not use CROSS environment variable as icc is mainly a
>  # x86->x86 compiler
>  
> -ifeq ($(KERNELRELEASE),)
>  CC        = icc
> -else
> -CC        = gcc
> -endif
> +KERNELCC  = gcc
>  CPP       = cpp
>  AS        = nasm
>  AR        = ar
> -- 
> 1.9.3
>

Thomas Monjalon Oct. 8, 2014, 5:15 p.m. UTC | #2

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?

Thanks

Bruce Richardson Oct. 9, 2014, 8:10 a.m. UTC | #3

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

Sergio Gonzalez Monroy Oct. 9, 2014, 10:04 a.m. UTC | #4

On Thu, Oct 09, 2014 at 09:10:04AM +0100, Bruce Richardson wrote:
> 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.
> 

I just did a bit more testing and it seems like it is not necessary to reset
CC, CC set from the command line takes precedence.

I will post a v2 with the fix.

Thanks,
Sergio

> /Bruce
> 
> > Thanks
> > -- 
> > Thomas

diff mbox

Patch

diff --git a/mk/rte.module.mk b/mk/rte.module.mk
index c4ca3fd..41c0d0f 100644
--- 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)
 
 # install module in $(RTE_OUTPUT)/kmod
 $(RTE_OUTPUT)/kmod/$(MODULE).ko: $(MODULE).ko
diff --git a/mk/target/generic/rte.vars.mk b/mk/target/generic/rte.vars.mk
index 6020f20..74ff771 100644
--- 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
diff --git a/mk/toolchain/clang/rte.vars.mk b/mk/toolchain/clang/rte.vars.mk
index ee4f451..40cb389 100644
--- a/mk/toolchain/clang/rte.vars.mk
+++ b/mk/toolchain/clang/rte.vars.mk
@@ -38,11 +38,8 @@ 
 #   - define TOOLCHAIN_ASFLAGS variable (overriden by cmdline value)
 #
 
-ifeq ($(KERNELRELEASE),)
 CC        = $(CROSS)clang
-else
-CC        = $(CROSS)gcc
-endif
+KERNELCC  = $(CROSS)gcc
 CPP       = $(CROSS)cpp
 # for now, we don't use as but nasm.
 # AS      = $(CROSS)as
diff --git a/mk/toolchain/gcc/rte.vars.mk b/mk/toolchain/gcc/rte.vars.mk
index 262ebdf..993eb26 100644
--- a/mk/toolchain/gcc/rte.vars.mk
+++ b/mk/toolchain/gcc/rte.vars.mk
@@ -39,6 +39,7 @@ 
 #
 
 CC        = $(CROSS)gcc
+KERNELCC  = $(CROSS)gcc
 CPP       = $(CROSS)cpp
 # for now, we don't use as but nasm.
 # AS      = $(CROSS)as
diff --git a/mk/toolchain/icc/rte.vars.mk b/mk/toolchain/icc/rte.vars.mk
index 612370d..f03a2a2 100644
--- a/mk/toolchain/icc/rte.vars.mk
+++ b/mk/toolchain/icc/rte.vars.mk
@@ -41,11 +41,8 @@ 
 # Warning: we do not use CROSS environment variable as icc is mainly a
 # x86->x86 compiler
 
-ifeq ($(KERNELRELEASE),)
 CC        = icc
-else
-CC        = gcc
-endif
+KERNELCC  = gcc
 CPP       = cpp
 AS        = nasm
 AR        = ar