Unused: avoid flaky behavior by forcing to make reachable content in case of incomplete reachable status

- Example: the class was made reachable as the base class (without making reachable out references), later that class may hit to visit itself.
 - In this case, the content of the class wouldn't be reachable.
 - It can be the source of flaky behavior because the results of the inspection run would depend on the visiting order.

(cherry picked from commit 62d457f7d85ebcf96d5ce990de40d7b0b0b88cfe)

IJ-CR-100952

GitOrigin-RevId: 4a921ebc61aed504030d00dd7ccbc55601c5ba68

java/java-analysis-impl/src/com/intellij/codeInspection/deadCode/UnusedDeclarationInspectionBase.java

@@ -594,6 +594,7 @@ public class UnusedDeclarationInspectionBase extends GlobalInspectionTool {
     private final Map<RefClass, Set<RefMethod>> myClassIDtoMethods = new HashMap<>();
     private final Set<RefClass> myInstantiatedClasses = new HashSet<>();
     private int myInstantiatedClassesCount;
+    private final Set<RefClass> myProcessedClasses = new HashSet<>();
     private final Set<RefMethod> myProcessedMethods = new HashSet<>();
     private final Set<RefFunctionalExpression> myProcessedFunctionalExpressions = new HashSet<>();
     private final Stack<RefElement> myNextRound = new Stack<>();
@@ -646,15 +647,13 @@ public class UnusedDeclarationInspectionBase extends GlobalInspectionTool {
     }
 
     @Override public void visitClass(@NotNull RefClass refClass) {
-      boolean alreadyActive = refClass.isReachable();
-      ((RefClassImpl)refClass).setReachable(true);
-
-      if (!alreadyActive) {
+      if (myProcessedClasses.add(refClass)) {
+        ((RefClassImpl)refClass).setReachable(true);
         // Process class's static initializers.
         makeReachable(refClass);
-      }
 
-      addInstantiatedClass(refClass);
+        addInstantiatedClass(refClass);
+      }
     }
 
     @Override public void visitField(@NotNull RefField field) {

java/java-tests/testData/inspection/deadCode/annotationInitializedByInheritedClassReference/expected.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<problems>
+</problems>
+

java/java-tests/testData/inspection/deadCode/annotationInitializedByInheritedClassReference/src/AnnotationsUtil.java

@@ -0,0 +1,20 @@
+import java.lang.annotation.*;
+
+public class AnnotationsUtil {
+  @Inherited
+  @Retention(RetentionPolicy.RUNTIME)
+  @Target(ElementType.TYPE)
+  private @interface PerClassLifeCycle {
+  }
+
+  @PerClassLifeCycle
+  private static class BaseMetaAnnotatedTestCase {
+  }
+
+  private static class SpecializedTestCase extends BaseMetaAnnotatedTestCase {
+  }
+
+  public static void main(String[] args) {
+    System.out.println(SpecializedTestCase.class);
+  }
+}

java/java-tests/testSrc/com/intellij/java/codeInspection/UnusedDeclarationInspectionTest.java

@@ -131,6 +131,10 @@ public class UnusedDeclarationInspectionTest extends AbstractUnusedDeclarationTe
     doTest();
   }
 
+  public void testAnnotationInitializedByInheritedClassReference() {
+    doTest();
+  }
+
   public void testUnusedEnum() {
     doTest5();
   }