PhanPossiblyUndeclaredVariable for variables defined in try blocks without catch

[DannyS712]

Basic reproduction case for phan 4.0.6 via https://phan.github.io/demo/

<?php

function doStuff() {
    try {
        $str = 'abc';
    } finally {
    }

    echo ( $str );
}

doStuff();

Running Analyze includes the warning input:9: PhanPossiblyUndeclaredVariable Variable $str is possibly undeclared
If there was a catch block that could handle any errors and still allow later code to be executed, it would make sense to treat $str as undeclared, because an error in creating $str would not prevent subsequent code that tries to use it from running. But, when there is no catch block, any error in declaring $str would bubble up and later code would not be executed, so if the later code is reached then the variable must be declared.

[DannyS712]

Sorry if this is a duplicate, I searched for PhanPossiblyUndeclaredVariable in open tasks and didn't see any

[TysonAndre]

It's similar to #3403 which may have predated PhanPossiblyUndeclaredVariable or been on a project that didn't enable it

I think the finally would need to be analyzed twice

1. Once without the try block, to analyze what would happen if any variable definitions were missing when the finally ran (approximately)
2. Once with the try block fully executed, to analyze what would happen for success (approximately)

And only the result of the second would be merged into the outer context.

[umherirrender]

A similar case with catch statements, but the scopes of the catches could be merged to the function scope, because the try block returns or the catch statements are running.

function doStuff() {
	try {
		return true;
	} catch ( \LogicException $e ) {
		$t = 'logic';
	} catch ( \Exception $e ) {
		$t = 'exception';
	}
	echo $t;  # PhanPossiblyUndeclaredVariable Variable $t is possibly undeclared
}