From mboxrd@z Thu Jan  1 00:00:00 1970
From: Christopher Li <sparse@chrisli.org>
Subject: Re: sparse: ARRAY_SIZE and sparse array initialization
Date: Sat, 29 Mar 2014 23:10:43 -0700
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To: Hans Verkuil <hverkuil@xs4all.nl>
Cc: Linux-Sparse <linux-sparse@vger.kernel.org>, Linux Media Mailing List <linux-media@vger.kernel.org>

On Fri, Mar 28, 2014 at 3:50 AM, Hans Verkuil <hverkuil@xs4all.nl> wrote:
> Is there any chance that the three issues I reported will be fixed? If not,
> then I'll work around it in the kernel code.
>

Most likely it is a sparse issue. Can you generate a minimal stand alone
test case that expose this bug? I try to simplify it as following, but
it does not
reproduce the error.


#define ARRAY_SIZE(x) (sizeof(x)/sizeof(x[0]))

static const char *v4l2_type_names[] = {
        [1]    = "mmap",
        [9] = "userptr",
        [2] = "overlay",
        [3] = "dmabuf",
};

#define prt_names(a, arr) (((unsigned)(a)) < ARRAY_SIZE(arr) ? arr[a]
: "unknown")


extern void prt(const char *name);

static void v4l_print_requestbuffers(const void *arg, int write_only)
{
        const struct v4l2_requestbuffers *p = arg;

        prt(prt_names(3, v4l2_type_names));
}


If you have the test case, you are welcome to submit a patch to
add the test case.

Chris