-----Original Message-----
> Date: Fri, 26 Jan 2018 12:10:16 +0530
> From: Pavan Nikhilesh <pbhagavat...@caviumnetworks.com>
> To: jerin.ja...@caviumnetworks.com, santosh.shu...@caviumnetworks.com,
> ferruh.yi...@intel.com
> Cc: dev@dpdk.org, Pavan Nikhilesh <pbhagavat...@caviumnetworks.com>
> Subject: [dpdk-dev] [PATCH v2] net/octeontx: use stub for building in old
> compilers
> X-Mailer: git-send-email 2.14.1
>
> Use stub for building clang < 4.0 as it doesn't support the following
> arm machine directives:
>
> .cpu
>
> Signed-off-by: Pavan Nikhilesh <pbhagavat...@caviumnetworks.com>
> ---
>
> v2 Changes:
> - use stub for older clang compilers instead of disabling PMD
>
> drivers/net/octeontx/Makefile | 8 ++++++++
> drivers/net/octeontx/base/octeontx_io.h | 2 +-
> 2 files changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/octeontx/Makefile b/drivers/net/octeontx/Makefile
> index b47bf7a40..5244eedd3 100644
> --- a/drivers/net/octeontx/Makefile
> +++ b/drivers/net/octeontx/Makefile
> @@ -30,6 +30,14 @@ SRCS-$(CONFIG_RTE_LIBRTE_OCTEONTX_PMD) += octeontx_pkivf.c
> SRCS-$(CONFIG_RTE_LIBRTE_OCTEONTX_PMD) += octeontx_bgx.c
> SRCS-$(CONFIG_RTE_LIBRTE_OCTEONTX_PMD) += octeontx_ethdev.c
>
> +ifeq ($(CONFIG_RTE_TOOLCHAIN_CLANG),y)
> +
> +ifeq ($(shell test $(CLANG_MAJOR_VERSION)$(CLANG_MINOR_VERSION) -lt 40 &&
> echo 1), 1)
> +CFLAGS += -D CLANG_BUILD_BUG
> +endif
> +
> +endif
> +
> ifeq ($(CONFIG_RTE_TOOLCHAIN_GCC),y)
> CFLAGS_octeontx_rxtx.o += -fno-prefetch-loop-arrays
>
> diff --git a/drivers/net/octeontx/base/octeontx_io.h
> b/drivers/net/octeontx/base/octeontx_io.h
> index d51ded236..1c0a941a5 100644
> --- a/drivers/net/octeontx/base/octeontx_io.h
> +++ b/drivers/net/octeontx/base/octeontx_io.h
> @@ -51,7 +51,7 @@ do {
> \
> } while (0)
> #endif
>
> -#if defined(RTE_ARCH_ARM64)
> +#if defined(RTE_ARCH_ARM64) && !defined(CLANG_BUILD_BUG)
It will build silently and break while running the PMD.
I think, We should disable building the PMD if dependencies are not meet.
Instead of building something that known to not work.
> /**
> * Perform an atomic fetch-and-add operation.
> */
> --
> 2.16.0
>
