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From: Keith Thompson <kst-u@mib.org>
Newsgroups: comp.lang.c
Subject: Re: Future of C
Date: Mon, 12 Mar 2018 18:29:02 -0700
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supercat@casperkitty.com writes:
[...]
> Is there any way in which the following program would not be Strictly
> Conforming:
>
>     void test(size_t n)
>     {
>       int arr[n];
>       arr[0] = 4;
>       arr[n-1] = 6;
>     }
>     int main(void)
>     {
>       test(-2);
>     }
>
> Conversion of the value -2 to a size_t has defined behavior, as would the
> declaration of the array.  On the other hand, one of the writes to arr[]
> might very well clobber the stack even on a platform where guard pages
> would normally ensure a shutdown in case of stack overflow.

I suppose it's strictly conforming, but it's very likely to exceed a
capacity limit at run time.

void test(void) {
    #define N ((size_t)-2)
    int arr[N];
    arr[0] = 4;
    arr[N-1] = 6;
}
int main(void) {
    test();
}

I fail to see what fundamentally new problems were introduced by VLAs
(when they were added to the language 19 years ago) that don't already
exist for fixed-length arrays.

-- 
Keith Thompson (The_Other_Keith) kst-u@mib.org  <http://www.ghoti.net/~kst>
Working, but not speaking, for JetHead Development, Inc.
"We must do something.  This is something.  Therefore, we must do this."
    -- Antony Jay and Jonathan Lynn, "Yes Minister"