From mboxrd@z Thu Jan  1 00:00:00 1970
From: Bruce Richardson <bruce.richardson-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Subject: Re: [PATCH] test-pmd: Fix pointer aliasing error
Date: Wed, 3 Dec 2014 11:42:58 +0000
Message-ID: <20141203114258.GA2396@bricha3-MOBL3>
References: <1417606044-3432-1-git-send-email-michael.qiu@intel.com>
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To: Michael Qiu <qdy220091330-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
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On Wed, Dec 03, 2014 at 07:28:19PM +0800, Michael Qiu wrote:
> app/test-pmd/csumonly.c: In function =E2=80=98get_psd_sum=E2=80=99:
> build/include/rte_ip.h:161: error: dereferencing pointer =E2=80=98u16=E2=
=80=99
> 	does break strict-aliasing rules
> build/include/rte_ip.h:157: note: initialized from here
> 	...
>=20
> The root cause is that, compile enable strict aliasing by default,
> while in function rte_raw_cksum() try to convert 'const char *'
> to 'const uint16_t *'.
>

What compiler version is this with? Is there any other way to fix this
other than disabling the compiler warnings. Turning off strict aliasing m=
ay
affect performance as it reduces the number of optimizations that the com=
piler
can perform.

/Bruce

> Need to add CFLAG '-Wno-strict-aliasing' to avoid this issue.
>=20
> Signed-off-by: Michael Qiu <michael.qiu-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> ---
>  app/test-pmd/Makefile | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>=20
> diff --git a/app/test-pmd/Makefile b/app/test-pmd/Makefile
> index 97dc2e6..995c874 100644
> --- a/app/test-pmd/Makefile
> +++ b/app/test-pmd/Makefile
> @@ -38,7 +38,7 @@ ifeq ($(CONFIG_RTE_TEST_PMD),y)
>  #
>  APP =3D testpmd
> =20
> -CFLAGS +=3D -O3
> +CFLAGS +=3D -O3 -Wno-strict-aliasing
>  CFLAGS +=3D $(WERROR_FLAGS)
> =20
>  ifeq ($(CONFIG_RTE_LIBRTE_PMD_PCAP),y)
> --=20
> 1.9.3
>=20