Why use a DFA instead of DIP1000?

[Dennis]

On Tuesday, 16 September 2025 at 10:47:03 UTC, Richard (Rikki) 
Andrew Cattermole wrote:
> It does actually.
>
> Godbolt has a control flow graph display for C#.
>
> https://csharp.godbolt.org/z/nMjPqYens
>
> ```
> Program:Main() (FullOpts):
>        xor      edi, edi
>        tail.jmp [System.Console:WriteLine(int)]
> ```
>
> It silently culled the branches. Exactly what DFA should do in 
> this situation.

I was referring to C#'s unused variable warnings that Adam 
brought up, not the code generator.

> And that would be a rewrite and I don't mean just DIP1000.
>
> Doing this stuff as part of the type system isn't the normal 
> way to handle it, and for good reason. Attaching a DFA engine 
> today directly into the type system to resolve this is quite 
> frankly too late. From what I've seen that would be a bad 
> direction to go in and have no desire to watch that being tried.

I don't understand this paragraph at all, you're referring to 5 
different things (rewrite, DIP1000, too late, type system, things 
you've seen) and I don't know the context/relevance of any of 
those.