On Jun 19 2021, Paul Smith wrote:
> But, as human programmers we can examine this code and understand that
> actually, it's never possible for p to point to the first character of
> the array: we know that eval_strings->idx is never 0, so we know that p
> will always be incremented past the beginning of the memory buffer:
>
> p = value = alloca (len);
> for (i = 0; i < eval_strings->idx; ++i)
> {
> ...
> *(p++) = ' ';
> }
> p[-1] = '\0';
The crux is of course to tell the compiler that eval_strings->idx is
always > 0, which is pretty hard for the compiler to deduce.
Andreas.
--
Andreas Schwab, SUSE Labs, [email protected]
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"And now for something completely different."
