From: Stephen Hemminger <stephen@networkplumber.org>
To: Bruce Richardson <bruce.richardson@intel.com>
Cc: dev@dpdk.org
Subject: Re: [dpdk-dev] [PATCH 01/10] mk: adjust gcc flags for new gcc 7 warnings
Date: Thu, 4 May 2017 09:38:08 -0700 [thread overview]
Message-ID: <20170504093808.12ea9c07@xeon-e3> (raw)
In-Reply-To: <20170504153822.19461-2-bruce.richardson@intel.com>
On Thu, 4 May 2017 16:38:13 +0100
Bruce Richardson <bruce.richardson@intel.com> wrote:
> There are two new warnings in GCC 7 that cause problems in the DPDK
> compile.
>
> 1. GCC now warns if you have a switch fall-through without a suitable
> comment indicating that it was intentional. The compiler supports a number
> of levels of warning which are triggered depending on the type of message
> used, with level 3 being the default. To accept a wider range of possible
> fall-through messages, we adjust this down to level 2.
>
> 2. GCC also warns about an snprintf where there may be truncation and the
> return value is not checked. Given that we often use snprintf in DPDK in
> place of strncpy, and in many cases where truncation is not a problem, we
> can just disable this particular warning.
>
> Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
> ---
> mk/toolchain/gcc/rte.vars.mk | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/mk/toolchain/gcc/rte.vars.mk b/mk/toolchain/gcc/rte.vars.mk
> index 5caa600..3834e00 100644
> --- a/mk/toolchain/gcc/rte.vars.mk
> +++ b/mk/toolchain/gcc/rte.vars.mk
> @@ -99,5 +99,12 @@ ifeq ($(shell test $(GCC_VERSION) -lt 47 && echo 1), 1)
> WERROR_FLAGS += -Wno-uninitialized
> endif
>
> +ifeq ($(shell test $(GCC_VERSION) -gt 70 && echo 1), 1)
> +# Tell GCC only to error for switch fallthroughs without a suitable comment
> +WERROR_FLAGS += -Wimplicit-fallthrough=2
> +# Ignore errors for snprintf truncation
> +WERROR_FLAGS += -Wno-format-truncation
> +endif
> +
> export CC AS AR LD OBJCOPY OBJDUMP STRIP READELF
> export TOOLCHAIN_CFLAGS TOOLCHAIN_LDFLAGS TOOLCHAIN_ASFLAGS
Please fix the code not neuter warnings
next prev parent reply other threads:[~2017-05-04 16:38 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-04 15:38 [dpdk-dev] [PATCH 00/10] Enable DPDK core build with gcc 7 Bruce Richardson
2017-05-04 15:38 ` [dpdk-dev] [PATCH 01/10] mk: adjust gcc flags for new gcc 7 warnings Bruce Richardson
2017-05-04 16:38 ` Stephen Hemminger [this message]
2017-05-05 9:42 ` Bruce Richardson
2017-05-05 10:02 ` Thomas Monjalon
2017-05-05 10:20 ` Bruce Richardson
2017-05-05 12:18 ` Van Haaren, Harry
2017-05-04 15:38 ` [dpdk-dev] [PATCH 02/10] drivers/net: disable new gcc 7 warnings for base code Bruce Richardson
2017-05-04 15:38 ` [dpdk-dev] [PATCH 03/10] net/bnx2x: fix warnings about switch fall-through Bruce Richardson
2017-05-04 15:38 ` [dpdk-dev] [PATCH 04/10] net/ixgbe: fix gcc 7 warning for switch fallthrough Bruce Richardson
2017-05-05 0:46 ` Lu, Wenzhuo
2017-05-04 15:38 ` [dpdk-dev] [PATCH 05/10] net/vmxnet3: fix compile error with gcc 7 Bruce Richardson
2017-05-04 16:39 ` Stephen Hemminger
2017-05-04 15:38 ` [dpdk-dev] [PATCH 06/10] lib: fix gcc 7 warnings for switch fall-through Bruce Richardson
2017-05-04 15:38 ` [dpdk-dev] [PATCH 07/10] net: fix missing break inside conditional compile block Bruce Richardson
2017-05-05 9:28 ` Singh, Jasvinder
2017-05-04 15:38 ` [dpdk-dev] [PATCH 08/10] app/testpmd: document explicit switch fall-through Bruce Richardson
2017-05-04 15:38 ` [dpdk-dev] [PATCH 09/10] test/test: fix missing break in switch Bruce Richardson
2017-05-04 15:38 ` [dpdk-dev] [PATCH 10/10] test/test: fix gcc 7 compiler error Bruce Richardson
2017-05-05 16:38 ` [dpdk-dev] [PATCH 00/10] Enable DPDK core build with gcc 7 Thomas Monjalon
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