Remember class_exists() from constructor

Author: staabm

Diff for: src/Analyser/MutatingScope.php

@@ -303,7 +303,14 @@ private function rememberConstructorExpressions(array $currentExpressionTypes):
 		$expressionTypes = [];
 		foreach ($currentExpressionTypes as $exprString => $expressionTypeHolder) {
 			$expr = $expressionTypeHolder->getExpr();
-			if ($expr instanceof PropertyFetch) {
+			if ($expr instanceof FuncCall) {
+				if (
+					!$expr->name instanceof Name
+					|| !in_array($expr->name->name, ['class_exists'], true)
+				) {
+					continue;
+				}
+			} elseif ($expr instanceof PropertyFetch) {
 				if (
 					!$expr->name instanceof Node\Identifier
 					|| !$expr->var instanceof Variable

Diff for: tests/PHPStan/Rules/Classes/ExistingClassInInstanceOfRuleTest.php

@@ -81,4 +81,9 @@ public function testBug7720(): void
 		]);
 	}
 
+	public function testRememberClassExistsFromConstructor(): void
+	{
+		$this->analyse([__DIR__ . '/data/remember-class-exists-from-constructor.php'], []);
+	}
+
 }

Diff for: tests/PHPStan/Rules/Classes/data/remember-class-exists-from-constructor.php

@@ -0,0 +1,24 @@
+<?php // lint >= 7.4
+
+namespace RememberClassExistsFromConstructor;
+
+use SomeUnknownClass;
+
+class User
+{
+	public function __construct(
+	) {
+		if (!class_exists('SomeUnknownClass')) {
+			throw new \LogicException();
+		}
+	}
+
+	public function doFoo($m): bool
+	{
+		if ($m instanceof SomeUnknownClass) {
+			return false;
+		}
+		return true;
+	}
+
+}