Re: [dpdk-dev] [PATCH v3 1/2] mk: fix build with gcc 4.4 and clang

[Vlad Zolotarov <vladz@cloudius-systems.com>]

On 04/17/15 01:10, Thomas Monjalon wrote:
> With GCC 4.4.7 from CentOS 6.5, the following errors arise:
>
> lib/librte_pmd_ixgbe/ixgbe_rxtx.c: In function 'ixgbe_dev_rx_queue_setup':
> lib/librte_pmd_ixgbe/ixgbe_rxtx.c:2509: error: missing initializer
> lib/librte_pmd_ixgbe/ixgbe_rxtx.c:2509: error: (near initialization for 'dev_info.driver_name')
>
> lib/librte_pmd_ixgbe/ixgbe_rxtx.c: In function 'ixgbe_set_rsc':
> lib/librte_pmd_ixgbe/ixgbe_rxtx.c:4072: error: missing initializer
> lib/librte_pmd_ixgbe/ixgbe_rxtx.c:4072: error: (near initialization for 'dev_info.driver_name')
>
> lib/librte_pmd_ixgbe/ixgbe_rxtx.c: In function 'ixgbe_recv_pkts_lro_single_alloc':
> lib/librte_pmd_ixgbe/ixgbe_rxtx.c:1479: error: 'next_rsc_entry' may be used uninitialized in this function
> lib/librte_pmd_ixgbe/ixgbe_rxtx.c:1480: error: 'next_rxe' may be used uninitialized in this function
>
> The "missing initializer" warning is a GCC bug which seems fixed in 4.7.
> The same warning is thrown by clang.
> The "may be used uninitialized" warning is another GCC bug which seems fixed in 4.7.
>
> Fixes: 8eecb3295aed ("ixgbe: add LRO support")
>
> Signed-off-by: Thomas Monjalon <thomas.monjalon@6wind.com>

Acked-by: Vlad Zolotarov <vladz@cloudius-systems.com>

> ---
> changes in v2:
> - option -Wno-missing-field-initializers for old GCC instead of code workaround
> changes in v3:
> - option -Wno-missing-field-initializers for clang
> - option -Wno-uninitialized for old GCC instead of code workaround (=NULL)
> - remove redundants -Wno-uninitialized from ixgbe Makefile
>
>   lib/librte_pmd_ixgbe/Makefile  | 4 ----
>   mk/toolchain/clang/rte.vars.mk | 3 +++
>   mk/toolchain/gcc/rte.vars.mk   | 9 +++++++++
>   3 files changed, 12 insertions(+), 4 deletions(-)
>
> diff --git a/lib/librte_pmd_ixgbe/Makefile b/lib/librte_pmd_ixgbe/Makefile
> index ae36202..fbf6966 100644
> --- a/lib/librte_pmd_ixgbe/Makefile
> +++ b/lib/librte_pmd_ixgbe/Makefile
> @@ -76,10 +76,6 @@ ifeq ($(shell test $(GCC_VERSION) -ge 50 && echo 1), 1)
>   CFLAGS_ixgbe_common.o += -Wno-logical-not-parentheses
>   endif
>   
> -ifeq ($(shell test $(GCC_VERSION) -le 46 && echo 1), 1)
> -CFLAGS_ixgbe_x550.o += -Wno-uninitialized
> -CFLAGS_ixgbe_phy.o += -Wno-uninitialized
> -endif
>   endif
>   
>   #
> diff --git a/mk/toolchain/clang/rte.vars.mk b/mk/toolchain/clang/rte.vars.mk
> index 40cb389..245ea7e 100644
> --- a/mk/toolchain/clang/rte.vars.mk
> +++ b/mk/toolchain/clang/rte.vars.mk
> @@ -72,5 +72,8 @@ WERROR_FLAGS += -Wundef -Wwrite-strings
>   # process cpu flags
>   include $(RTE_SDK)/mk/toolchain/$(RTE_TOOLCHAIN)/rte.toolchain-compat.mk
>   
> +# workaround clang bug with warning "missing field initializer" for "= {0}"
> +WERROR_FLAGS += -Wno-missing-field-initializers
> +
>   export CC AS AR LD OBJCOPY OBJDUMP STRIP READELF
>   export TOOLCHAIN_CFLAGS TOOLCHAIN_LDFLAGS TOOLCHAIN_ASFLAGS
> diff --git a/mk/toolchain/gcc/rte.vars.mk b/mk/toolchain/gcc/rte.vars.mk
> index 88f235c..0f51c66 100644
> --- a/mk/toolchain/gcc/rte.vars.mk
> +++ b/mk/toolchain/gcc/rte.vars.mk
> @@ -80,5 +80,14 @@ WERROR_FLAGS += -Wundef -Wwrite-strings
>   # process cpu flags
>   include $(RTE_SDK)/mk/toolchain/$(RTE_TOOLCHAIN)/rte.toolchain-compat.mk
>   
> +# workaround GCC bug with warning "missing initializer" for "= {0}"
> +ifeq ($(shell test $(GCC_VERSION) -lt 47 && echo 1), 1)
> +WERROR_FLAGS += -Wno-missing-field-initializers
> +endif
> +# workaround GCC bug with warning "may be used uninitialized"
> +ifeq ($(shell test $(GCC_VERSION) -lt 47 && echo 1), 1)
> +WERROR_FLAGS += -Wno-uninitialized
> +endif
> +
>   export CC AS AR LD OBJCOPY OBJDUMP STRIP READELF
>   export TOOLCHAIN_CFLAGS TOOLCHAIN_LDFLAGS TOOLCHAIN_ASFLAGS