Add support for get_parent_class() with no args

src/Psalm/Internal/Analyzer/FunctionAnalyzer.php

@@ -82,6 +82,24 @@ class FunctionAnalyzer extends FunctionLikeAnalyzer
 
                 case 'microtime':
                     return Type::getString();
+
+                case 'get_called_class':
+                    return new Type\Union([new Type\Atomic\TClassString($context->self ?: 'object')]);
+
+                case 'get_parent_class':
+                    $codebase = $statements_analyzer->getCodebase();
+
+                    if ($context->self && $codebase->classExists($context->self)) {
+                        $classlike_storage = $codebase->classlike_storage_provider->get($context->self);
+
+                        if ($classlike_storage->parent_classes) {
+                            return new Type\Union([
+                                new Type\Atomic\TClassString(
+                                    array_values($classlike_storage->parent_classes)[0]
+                                )
+                            ]);
+                        }
+                    }
             }
         } else {
             switch ($call_map_key) {

tests/ClassStringTest.php

@@ -322,6 +322,17 @@ class ClassStringTest extends TestCase
                         return $a::class;
                     }',
             ],
+            'returnGetCalledClassClassStringParameterized' => [
+                '<?php
+                    class A {
+                        /**
+                         * @return class-string<A> $s
+                         */
+                        function foo() : string {
+                            return get_called_class();
+                        }
+                    }',
+            ],
             'returnGetClassClassStringParameterized' => [
                 '<?php
                     class A {}
@@ -333,6 +344,19 @@ class ClassStringTest extends TestCase
                         return get_class($a);
                     }',
             ],
+            'returnGetParentClassClassStringParameterized' => [
+                '<?php
+                    class A {}
+
+                    class B extends A {
+                        /**
+                         * @return class-string<A> $s
+                         */
+                        function foo() : string {
+                            return get_parent_class();
+                        }
+                    }',
+            ],
             'createClassOfTypeFromString' => [
                 '<?php
                     class A {}