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

[Sergio Gonzalez Monroy <sergio.gonzalez.monroy@intel.com>]

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(-)

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