From b5ebeda9496f71b2be4fdbd965f1f1d36abfe86a Mon Sep 17 00:00:00 2001
From: Joe Savona <joesavona@fb.com>
Date: Tue, 3 Jun 2025 17:00:47 -0700
Subject: [PATCH] Update base for Update on "[compiler] Distinguish
 Alias/Assign effects"
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Alias was akward becuase it had a specific data flow / mutability relationship — direct mutations affect both sides - but also populated the output. We need the ability to express the aliasing dataflwo/mutability relationship w/o expressing actual assignment.

An example of this is that for an unknown method call `const z = x.y()`, we want to express the Alias-style mutability relationship btw z and x (Muate(z) => Mutate(x)), but we want to assume that `z !== x`.

This ends up being really clean, the places that should use Assign are very obvious (LoadLocal, StoreLocal) and most places keep using Alias.

[ghstack-poisoned]