Remember resolved types after pushInFunctionCall

[staabm]

prevents duplicate work, as MethodCalls will re-calculated one less time.

analysing

<?php

class Foo
{

	public function doFoo(DateTimeImmutable $d): void
	{
		$a = $d->format('j. n. Y');
	}

}

before this PR reaches “if ($node instanceof MethodCall) {“ in MutatingScope.php:2161 4 times.
after the PR only 3 times.

with PHPSTAN_FNSR=1 php bin/phpstan analyze foo.php --debug after PR its only 2 times.

---

➜  phpstan-src git:(push-resolve) ✗ hyperfine -i 'php bin/phpstan analyze foo.php --debug'
Benchmark 1: php bin/phpstan analyze foo.php --debug
  Time (mean ± σ):     743.8 ms ±   1.8 ms    [User: 578.3 ms, System: 161.6 ms]
  Range (min … max):   741.5 ms … 747.1 ms    10 runs
 
  Warning: Ignoring non-zero exit code.
 
➜  phpstan-src git:(push-resolve) ✗ hyperfine -i 'php bin/phpstan analyze foo.php'        
Benchmark 1: php bin/phpstan analyze foo.php
  Time (mean ± σ):      1.047 s ±  0.005 s    [User: 0.777 s, System: 0.255 s]
  Range (min … max):    1.039 s …  1.054 s    10 runs
 
  Warning: Ignoring non-zero exit code.
  
➜  phpstan-src git:(2.1.x) ✗ hyperfine -i 'php bin/phpstan analyze foo.php --debug'
Benchmark 1: php bin/phpstan analyze foo.php --debug
  Time (mean ± σ):     754.9 ms ±   3.3 ms    [User: 587.2 ms, System: 164.1 ms]
  Range (min … max):   752.6 ms … 761.7 ms    10 runs
 
  Warning: Ignoring non-zero exit code.
 
➜  phpstan-src git:(2.1.x) ✗ hyperfine -i 'php bin/phpstan analyze foo.php'        
Benchmark 1: php bin/phpstan analyze foo.php
  Time (mean ± σ):      1.119 s ±  0.054 s    [User: 0.792 s, System: 0.260 s]
  Range (min … max):    1.055 s …  1.166 s    10 runs
 
  Warning: Ignoring non-zero exit code.

[ondrejmirtes]

1. Could be in popInFunctionCall too
2. BUT: $this->inFunctionCallsStack is used in resolveType() in } elseif ($node instanceof Expr\Closure || $node instanceof Expr\ArrowFunction) { so that could be a problem (the problem should be reproduced in a test first).

[ondrejmirtes]

Issue bot points out an example where this breaks https://phpstan.org/r/dfc26675-234f-47b3-8d0f-dc64b66ef5aa

[staabm]

2. BUT: $this->inFunctionCallsStack is used in resolveType() in } elseif ($node instanceof Expr\Closure || $node instanceof Expr\ArrowFunction) { so that could be a problem (the problem should be reproduced in a test first).

I think this problem was caught by existing tests, as the suite failed with the change until I got it right.

[phpstan-bot]

This pull request has been marked as ready for review.

[ondrejmirtes]

Perfect! Thank you. My idea for preserving resolvedTypes in often-called methods like assignVariable, mergeWith, specifyExpressionType is to have something like $scope->resolvedTypes = $this->preserveResolvedTypes($newExpressionTypes) before return $scope;.

This logic doesn't have to be called in methods like enterDeclareStrictTypes, enterClass, enterNamespace because there are unlikely to be any expressions.

And the implementation of preserveResolvedTypes would look at changes between $this->expressionTypes and $newExpressionTypes. For example - if the new scope doesn't change anything about $a, we can preserve resolved types about $a.

This logic is very similar to what invalidateExpression does. But of course the risk is that the logic to figure out what cached types to preserve would be more expensive than to just empty the whole cache every time. So even if we have a proper implementation of the idea and all tests pass, we have to measure whether it's any faster.

Do you think you want to look into this?

[staabm]

I can have a look

[staabm]

My idea for preserving resolvedTypes in often-called methods like assignVariable, mergeWith, specifyExpressionType is to have something like $scope->resolvedTypes = $this->preserveResolvedTypes($newExpressionTypes) before return $scope;.

I am not sure the memory/perf tradeoff will be good in this direction. a different direction to explore could be trying to implement TypeTraverser natively.

it seems bootleneck enough and way less complex than a TypeCombinator re-implementation in e.g. rust

see blackfire run php vendor/bin/phpunit tests/PHPStan/Analyser/NodeScopeResolverTest.php