Treat all in-scope variables as used when an unused-parameter body accesses a variable variable ($$name)

src/Rules/UnusedFunctionParametersCheck.php

@@ -82,8 +82,21 @@ private function getUsedVariables(Scope $scope, $node): array
 			if ($node instanceof Node\Expr\Include_ || $node instanceof Node\Expr\Eval_) {
 				return $scope->getDefinedVariables();
 			}
-			if ($node instanceof Variable && is_string($node->name) && $node->name !== 'this') {
-				return [$node->name];
+			if ($node instanceof Variable) {
+				if (is_string($node->name)) {
+					if ($node->name !== 'this') {
+						return [$node->name];
+					}
+				} else {
+					$nameType = $scope->getType($node->name);
+					if ($nameType->getConstantStrings() === []) {
+						return $scope->getDefinedVariables();
+					}
+
+					foreach ($nameType->getConstantStrings() as $constantString) {
+						$variableNames[] = $constantString->getValue();
+					}
+				}
 			}
 			if ($node instanceof Node\ClosureUse && is_string($node->var->name)) {
 				return [$node->var->name];

tests/PHPStan/Rules/Classes/data/unused-constructor-parameters-include.php

@@ -13,3 +13,16 @@ public function __construct(
 	}
 
 }
+
+class Bar
+{
+
+	public function __construct(
+		$usedViaVariableVariable,
+		$name
+	)
+	{
+		echo $$name;
+	}
+
+}

tests/PHPStan/Rules/Functions/UnusedClosureUsesRuleTest.php

@@ -32,6 +32,10 @@ public function testUnusedClosureUses(): void
 				'Anonymous function has an unused use $usedInClosureUse.',
 				10,
 			],
+			[
+				'Anonymous function has an unused use $container.',
+				43,
+			],
 		]);
 	}
 

tests/PHPStan/Rules/Functions/data/unused-closure-uses.php

@@ -25,3 +25,21 @@ function () use ($container) {
 function () use ($container) {
 	eval('echo $container;');
 };
+
+$aap = 684;
+
+$a = function () use ($aap) {
+	require __DIR__ . '/echo_the_value_of_aap.php';
+};
+
+$name = 'container';
+
+function () use ($container, $name) {
+	echo $$name;
+};
+
+$otherName = 'notContainer';
+
+function () use ($container, $otherName) {
+	echo $$otherName;
+};