Hm, doesn't this need to be on the op array context instead? Otherwise we only warn once per compilation instead of once per file?

I've added tests and it seems to work as I expect it

Yeah okay I see I actually think I wanted to say "once per op_array", but if that's the intention that's fine I guess?

But it seems to be once per op_array 🤔

I'll check this again tomorrow when I'm more awake

I see you reset the variable when a new op context starts, but they can be nested. So the following emits 2 deprecations even though it should only emit 1 (artificial example I know, but a simple one):

<?php
function foo() {
    $http_response_header = "foo";
    function nested() {
        echo $http_response_header;
    }
    echo $http_response_header;
}

You can remove the code from "nested" and it will still emit a deprecation that should not be happening.

I see you reset the variable when a new op context starts, but they can be nested. So the following emits 2 deprecations even though it should only emit 1 (artificial example I know, but a simple one):

<?php
function foo() {
    $http_response_header = "foo";
    function nested() {
        echo $http_response_header;
    }
    echo $http_response_header;
}

You can remove the code from "nested" and it will still emit a deprecation that should not be happening.