Classes that just reference themselves aren’t used

src/Psalm/Internal/Analyzer/Statements/Expression/Call/StaticCallAnalyzer.php

@@ -210,7 +210,9 @@ class StaticCallAnalyzer extends \Psalm\Internal\Analyzer\Statements\Expression\
                     $fq_class_name,
                     new CodeLocation($source, $stmt->class),
                     $statements_analyzer->getSuppressedIssues(),
-                    false
+                    $stmt->class instanceof PhpParser\Node\Name
+                        && !count($stmt->class->parts) !== 1
+                        && in_array(strtolower($stmt->class->parts[0]), ['self', 'static'], true)
                 )) {
                     return false;
                 }

tests/UnusedCodeTest.php

@@ -929,6 +929,18 @@ class UnusedCodeTest extends TestCase
                     }',
                 'error_message' => 'UnusedMethodCall',
             ],
+            'unusedClassReferencesItself' => [
+                '<?php
+                    class A {}
+
+                    class AChild extends A {
+                        public function __construct() {
+                            self::foo();
+                        }
+                        public static function foo() : void {}
+                    }',
+                'error_message' => 'UnusedClass',
+            ],
         ];
     }
 }