Do not infer false for get_class() without arguments on PHP 8

get_class() without arguments outside of a class returns false on PHP 7,
but PHP 8 throws Error instead. In a function it always throws, so it is
never now. Top-level code might be included from a method and a closure
bound to an object, where it returns the class name, so it is class-string
there.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Dhb4ssXuKVWcVBcNFpsdn7

Author: ondrejmirtes

src/Type/Php/GetClassDynamicReturnTypeExtension.php

@@ -5,11 +5,13 @@
 use PhpParser\Node\Expr\FuncCall;
 use PHPStan\Analyser\Scope;
 use PHPStan\DependencyInjection\AutowiredService;
+use PHPStan\Php\PhpVersion;
 use PHPStan\Reflection\FunctionReflection;
 use PHPStan\Type\ClassStringType;
 use PHPStan\Type\Constant\ConstantBooleanType;
 use PHPStan\Type\Constant\ConstantStringType;
 use PHPStan\Type\DynamicFunctionReturnTypeExtension;
+use PHPStan\Type\NeverType;
 use PHPStan\Type\Type;
 use PHPStan\Type\TypeUtils;
 use function count;
@@ -18,6 +20,10 @@
 final class GetClassDynamicReturnTypeExtension implements DynamicFunctionReturnTypeExtension
 {
 
+	public function __construct(private PhpVersion $phpVersion)
+	{
+	}
+
 	public function isFunctionSupported(FunctionReflection $functionReflection): bool
 	{
 		return $functionReflection->getName() === 'get_class';
@@ -36,6 +42,16 @@ public function getTypeFromFunctionCall(FunctionReflection $functionReflection,
 				return new ConstantStringType($scope->getClassReflection()->getName(), true);
 			}
 
+			// PHP 8 throws Error instead of returning false. Top-level code
+			// might be included from a method and a closure bound to an object.
+			if ($this->phpVersion->throwsValueErrorForInternalFunctions()) {
+				if ($scope->getFunction() !== null && !$scope->isInAnonymousFunction()) {
+					return new NeverType(true);
+				}
+
+				return new ClassStringType();
+			}
+
 			return new ConstantBooleanType(false);
 		}
 

tests/PHPStan/Analyser/nsrt/get-class-without-argument-php7.php

@@ -0,0 +1,26 @@
+<?php // lint < 8.0
+
+namespace GetClassWithoutArgumentPhp7;
+
+use function PHPStan\Testing\assertType;
+
+class Foo
+{
+
+	public function doFoo(): void
+	{
+		assertType('\'GetClassWithoutArgumentPhp7\\\\Foo\'', get_class());
+	}
+
+}
+
+function doBar(): void
+{
+	assertType('false', get_class());
+}
+
+function (): void {
+	assertType('false', get_class());
+};
+
+assertType('false', get_class());

tests/PHPStan/Analyser/nsrt/get-class-without-argument-php8.php

@@ -0,0 +1,26 @@
+<?php // lint >= 8.0
+
+namespace GetClassWithoutArgumentPhp8;
+
+use function PHPStan\Testing\assertType;
+
+class Foo
+{
+
+	public function doFoo(): void
+	{
+		assertType('\'GetClassWithoutArgumentPhp8\\\\Foo\'', get_class());
+	}
+
+}
+
+function doBar(): void
+{
+	assertType('*NEVER*', get_class());
+}
+
+function (): void {
+	assertType('class-string', get_class());
+};
+
+assertType('class-string', get_class());

tests/PHPStan/Analyser/nsrt/get-parent-class.php

@@ -37,7 +37,6 @@ function (string $s) {
 	assertType('class-string|false', get_parent_class(NonexistentClass::class));
 	assertType('class-string|false', get_parent_class(1));
 	assertType('\'ParentClass\\\\Foo\'', get_parent_class(\ParentClass\Bar::class));
-	assertType('false', get_class());
 };
 
 trait FooTrait