Fix phpstan/phpstan#14241: Cannot re-assign auto-global variable in parameters

Co-authored-by: Markus Staab <markus.staab@redaxo.de>
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: 3 people

Makefile

@@ -132,6 +132,7 @@ lint:
 		--exclude tests/PHPStan/Rules/Classes/data/bug-14250-promoted-properties.php \
 		--exclude tests/PHPStan/Rules/Operators/data/bug-3585.php \
 		--exclude tests/PHPStan/Rules/EnumCases/data/bug-14252.php \
+		--exclude tests/PHPStan/Rules/Functions/data/bug-14241.php \
 		src tests
 
 install-paratest:

src/Rules/Functions/InvalidParameterNameRule.php

@@ -0,0 +1,59 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Rules\Functions;
+
+use PhpParser\Node;
+use PHPStan\Analyser\Scope;
+use PHPStan\DependencyInjection\RegisteredRule;
+use PHPStan\Rules\Rule;
+use PHPStan\Rules\RuleErrorBuilder;
+use function in_array;
+use function is_string;
+use function sprintf;
+
+/**
+ * @implements Rule<Node\Param>
+ */
+#[RegisteredRule(level: 0)]
+final class InvalidParameterNameRule implements Rule
+{
+
+	public function getNodeType(): string
+	{
+		return Node\Param::class;
+	}
+
+	public function processNode(Node $node, Scope $scope): array
+	{
+		if (!$node->var instanceof Node\Expr\Variable) {
+			return [];
+		}
+
+		if (!is_string($node->var->name)) {
+			return [];
+		}
+
+		$variableName = $node->var->name;
+
+		if (in_array($variableName, Scope::SUPERGLOBAL_VARIABLES, true)) {
+			return [
+				RuleErrorBuilder::message(sprintf('Superglobal variable $%s cannot be used as a parameter.', $variableName))
+					->identifier('parameter.superglobal')
+					->nonIgnorable()
+					->build(),
+			];
+		}
+
+		if ($variableName === 'this') {
+			return [
+				RuleErrorBuilder::message('Cannot use $this as parameter.')
+					->identifier('parameter.this')
+					->nonIgnorable()
+					->build(),
+			];
+		}
+
+		return [];
+	}
+
+}

tests/PHPStan/Rules/Functions/InvalidParameterNameRuleTest.php

@@ -0,0 +1,65 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Rules\Functions;
+
+use PHPStan\Rules\Rule;
+use PHPStan\Testing\RuleTestCase;
+
+/**
+ * @extends RuleTestCase<InvalidParameterNameRule>
+ */
+class InvalidParameterNameRuleTest extends RuleTestCase
+{
+
+	protected function getRule(): Rule
+	{
+		return new InvalidParameterNameRule();
+	}
+
+	public function testRule(): void
+	{
+		$this->analyse([__DIR__ . '/data/bug-14241.php'], [
+			[
+				'Superglobal variable $_FILES cannot be used as a parameter.',
+				5,
+			],
+			[
+				'Superglobal variable $_GET cannot be used as a parameter.',
+				7,
+			],
+			[
+				'Superglobal variable $_POST cannot be used as a parameter.',
+				7,
+			],
+			[
+				'Superglobal variable $_SERVER cannot be used as a parameter.',
+				13,
+			],
+			[
+				'Superglobal variable $_SESSION cannot be used as a parameter.',
+				15,
+			],
+			[
+				'Superglobal variable $_COOKIE cannot be used as a parameter.',
+				18,
+			],
+			[
+				'Superglobal variable $_REQUEST cannot be used as a parameter.',
+				20,
+			],
+			[
+				'Superglobal variable $_ENV cannot be used as a parameter.',
+				22,
+			],
+			[
+				'Superglobal variable $GLOBALS cannot be used as a parameter.',
+				24,
+			],
+			[
+				'Cannot use $this as parameter.',
+				26,
+			],
+		]);
+	}
+
+}

tests/PHPStan/Rules/Functions/data/bug-14241.php

@@ -0,0 +1,26 @@
+<?php declare(strict_types = 1);
+
+namespace Bug14241;
+
+function doFoo($_FILES): void {}
+
+function doBar($_GET, $_POST): void {}
+
+function doBaz($ok): void {}
+
+class Foo
+{
+	public function doFoo($_SERVER): void {}
+
+	public static function doBar($_SESSION): void {}
+}
+
+$f = function ($_COOKIE): void {};
+
+$g = fn ($_REQUEST) => $_REQUEST;
+
+function doQux($_ENV): void {}
+
+function doQuux($GLOBALS): void {}
+
+function doThis($this) {}