[DTrace-devel] [PATCH] alloca: fix subtraction of two alloca pointers

[Eugene Loh]

Reviewed-by: Eugene Loh <eugene.loh at oracle.com>
though...

On 8/30/25 01:55, Kris Van Hees wrote:
> diff --git a/test/unittest/funcs/alloca/tst.alloca-arith.d b/test/unittest/funcs/alloca/tst.alloca-arith.d
> @@ -0,0 +1,29 @@
> +BEGIN
> +{
> +	x = (char *)alloca(1);

This is okay, but is it dead, vestigial code?

> +	x = (char *)alloca(10);
> +	y = (char *)alloca(1);
> +	z = y - x;
> +	z /= 8;

This is okay, but how about skipping the /8 and just testing for 16?  If 
you're worried about padding changes in the future(?), then the x 
alloca() could become alloca(16).

> +	exit(z == 2 ? 0 : 1);
> +}