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Date: Thu, 28 May 2009 21:18:16 +0800
Message-ID: <3877989d0905280618idba1b35x72ecc222c5cf16a2@mail.gmail.com>
Subject: Re: [Patch] kbuild: fix a compile warning
From: Luming Yu <luming.yu@gmail.com>
To: Amerigo Wang <amwang@redhat.com>
Cc: linux-kernel@vger.kernel.org, akpm@linux-foundation.org,
       Sam Ravnborg <sam@ravnborg.org>
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On Fri, May 15, 2009 at 3:51 PM, Amerigo Wang <amwang@redhat.com> wrote:
>
> I got this warning:
>
>  HOSTCC  scripts/basic/fixdep
> scripts/basic/fixdep.c: In function 'traps':
> scripts/basic/fixdep.c:377: warning: dereferencing type-punned pointer will break strict-aliasing rules
> scripts/basic/fixdep.c:379: warning: dereferencing type-punned pointer will break strict-aliasing rules


these warnings can be supressed by adding a compile option -fno-strict-aliasing


>
> Patch below fixes it.
>
> Signed-off-by: WANG Cong <amwang@redhat.com>
> Cc: Sam Ravnborg <sam@ravnborg.org>
>
> ---
> diff --git a/scripts/basic/fixdep.c b/scripts/basic/fixdep.c
> index 8912c0f..72c1520 100644
> --- a/scripts/basic/fixdep.c
> +++ b/scripts/basic/fixdep.c
> @@ -373,10 +373,11 @@ void print_deps(void)
>  void traps(void)
>  {
>        static char test[] __attribute__((aligned(sizeof(int)))) = "CONF";
> +       int *p = (int *)test;
>
> -       if (*(int *)test != INT_CONF) {
> +       if (*p != INT_CONF) {
>                fprintf(stderr, "fixdep: sizeof(int) != 4 or wrong endianess? %#x\n",
> -                       *(int *)test);
> +                       *p);
>                exit(2);
>        }
>  }
> --
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