Always create descriptors for class object psi element in lazy resolve

KT-4397 Exception: @NotNull method org/jetbrains/jet/lang/resolve/lazy/ResolveSession.getClassDescriptor must not return null

 #KT-4397 Fixed

compiler/frontend/src/org/jetbrains/jet/lang/resolve/lazy/ResolveSession.java

@@ -214,7 +214,8 @@ public class ResolveSession implements KotlinCodeAnalyzer {
         return (ClassDescriptor) declaration;
     }
 
-    /*package*/ LazyClassDescriptor getClassObjectDescriptor(JetClassObject classObject) {
+    @NotNull
+    /*package*/ LazyClassDescriptor getClassObjectDescriptor(@NotNull JetClassObject classObject) {
         JetClass aClass = PsiTreeUtil.getParentOfType(classObject, JetClass.class);
 
         final LazyClassDescriptor parentClassDescriptor;
@@ -237,16 +238,18 @@ public class ResolveSession implements KotlinCodeAnalyzer {
             // It's possible that there are several class objects and another class object is taking part in lazy resolve. We still want to
             // build descriptors for such class objects.
             final JetClassLikeInfo classObjectInfo = parentClassDescriptor.getClassObjectInfo(classObject);
-            if (classObjectInfo != null) {
-                final Name name = SpecialNames.getClassObjectName(parentClassDescriptor.getName());
-                return storageManager.compute(new Function0<LazyClassDescriptor>() {
-                    @Override
-                    public LazyClassDescriptor invoke() {
-                        // Create under lock to avoid premature access to published 'this'
-                        return new LazyClassDescriptor(ResolveSession.this, parentClassDescriptor, name, classObjectInfo);
-                    }
-                });
-            }
+            assert classObjectInfo != null :
+                    String.format("Failed to find class object info for existent class object declaration: %s",
+                                  JetPsiUtil.getElementTextWithContext(classObject));
+
+            final Name name = SpecialNames.getClassObjectName(parentClassDescriptor.getName());
+            return storageManager.compute(new Function0<LazyClassDescriptor>() {
+                @Override
+                public LazyClassDescriptor invoke() {
+                    // Create under lock to avoid premature access to published 'this'
+                    return new LazyClassDescriptor(ResolveSession.this, parentClassDescriptor, name, classObjectInfo);
+                }
+            });
         }
 
         return (LazyClassDescriptor) declaration;

compiler/frontend/src/org/jetbrains/jet/lang/resolve/lazy/descriptors/LazyClassDescriptor.java

@@ -258,9 +258,6 @@ public class LazyClassDescriptor extends ClassDescriptorBase implements LazyDesc
     @Nullable
     public JetClassLikeInfo getClassObjectInfo(JetClassObject classObject) {
         if (classObject != null) {
-            if (!DescriptorUtils.inStaticContext(this)) {
-                return null;
-            }
             JetObjectDeclaration objectDeclaration = classObject.getObjectDeclaration();
             if (objectDeclaration != null) {
                 return JetClassInfoUtil.createClassLikeInfo(objectDeclaration);
@@ -269,6 +266,7 @@ public class LazyClassDescriptor extends ClassDescriptorBase implements LazyDesc
         else if (getKind() == ClassKind.OBJECT || getKind() == ClassKind.ENUM_ENTRY || getKind() == ClassKind.ENUM_CLASS) {
             return new SyntheticClassObjectInfo(originalClassInfo, this);
         }
+
         return null;
     }
 

compiler/testData/loadJava/compiledKotlin/annotations/classes/ClassObjectInStaticNestedClass.kt

@@ -0,0 +1,9 @@
+package test
+
+class A {
+    class B {
+        class object {
+            val TEST = 1
+        }
+    }
+}

compiler/testData/loadJava/compiledKotlin/annotations/classes/ClassObjectInStaticNestedClass.txt

@@ -0,0 +1,15 @@
+package test
+
+internal final class A {
+    /*primary*/ public constructor A()
+    
+    internal final class B {
+        /*primary*/ public constructor B()
+        
+        internal class object <class-object-for-B> {
+            /*primary*/ private constructor <class-object-for-B>()
+            internal final val TEST: jet.Int
+                internal final fun <get-TEST>(): jet.Int
+        }
+    }
+}

compiler/tests/org/jetbrains/jet/jvm/compiler/LoadJavaTestGenerated.java

@@ -1577,6 +1577,11 @@ public class LoadJavaTestGenerated extends AbstractLoadJavaTest {
                     doTestCompiledKotlin("compiler/testData/loadJava/compiledKotlin/annotations/classes/ClassObject.kt");
                 }
                 
+                @TestMetadata("ClassObjectInStaticNestedClass.kt")
+                public void testClassObjectInStaticNestedClass() throws Exception {
+                    doTestCompiledKotlin("compiler/testData/loadJava/compiledKotlin/annotations/classes/ClassObjectInStaticNestedClass.kt");
+                }
+                
                 @TestMetadata("Deprecated.kt")
                 public void testDeprecated() throws Exception {
                     doTestCompiledKotlin("compiler/testData/loadJava/compiledKotlin/annotations/classes/Deprecated.kt");

compiler/tests/org/jetbrains/jet/lang/resolve/lazy/LazyResolveNamespaceComparingTestGenerated.java

@@ -105,6 +105,11 @@ public class LazyResolveNamespaceComparingTestGenerated extends AbstractLazyReso
                     doTestCheckingPrimaryConstructorsAndAccessors("compiler/testData/loadJava/compiledKotlin/annotations/classes/ClassObject.kt");
                 }
                 
+                @TestMetadata("ClassObjectInStaticNestedClass.kt")
+                public void testClassObjectInStaticNestedClass() throws Exception {
+                    doTestCheckingPrimaryConstructorsAndAccessors("compiler/testData/loadJava/compiledKotlin/annotations/classes/ClassObjectInStaticNestedClass.kt");
+                }
+                
                 @TestMetadata("Deprecated.kt")
                 public void testDeprecated() throws Exception {
                     doTestCheckingPrimaryConstructorsAndAccessors("compiler/testData/loadJava/compiledKotlin/annotations/classes/Deprecated.kt");

core/descriptors/src/org/jetbrains/jet/lang/resolve/DescriptorUtils.java

@@ -310,22 +310,6 @@ public class DescriptorUtils {
         return superClassDescriptor.equals(KotlinBuiltIns.getInstance().getAny());
     }
 
-    public static boolean inStaticContext(@NotNull DeclarationDescriptor descriptor) {
-        DeclarationDescriptor containingDeclaration = descriptor.getContainingDeclaration();
-        if (containingDeclaration instanceof PackageFragmentDescriptor) {
-            return true;
-        }
-        if (containingDeclaration instanceof ClassDescriptor) {
-            ClassDescriptor classDescriptor = (ClassDescriptor) containingDeclaration;
-
-            if (classDescriptor.getKind().isSingleton()) {
-                return inStaticContext(classDescriptor.getContainingDeclaration());
-            }
-
-        }
-        return false;
-    }
-
     public static boolean isEnumClassObject(@NotNull DeclarationDescriptor descriptor) {
         if (descriptor instanceof ClassDescriptor && ((ClassDescriptor) descriptor).getKind() == ClassKind.CLASS_OBJECT) {
             DeclarationDescriptor containing = descriptor.getContainingDeclaration();

idea/testData/codeInsight/lineMarker/ClassObjectInStaticNestedClass.kt

@@ -0,0 +1,12 @@
+trait <lineMarker></lineMarker>TestTrait {
+    fun <lineMarker></lineMarker>test()
+}
+
+class A {
+    class B {
+        class object : TestTrait { // TODO: No line marker
+            override fun <lineMarker descr="<b>internal</b> <b>open</b> <b>fun</b> test(): jet.Unit <i>defined in</i> A.B.&lt;class-object-for-B&gt;<br/>implements<br/><b>internal</b> <b>abstract</b> <b>fun</b> test(): jet.Unit <i>defined in</i> TestTrait"></lineMarker>test() {
+            }
+        }
+    }
+}

idea/tests/org/jetbrains/jet/plugin/codeInsight/OverrideImplementLineMarkerTest.java

@@ -61,6 +61,10 @@ public class OverrideImplementLineMarkerTest extends JetLightCodeInsightFixtureT
         doTest();
     }
 
+    public void testClassObjectInStaticNestedClass() throws Exception {
+        doTest();
+    }
+
     public void testFakeOverrideProperty() throws Exception {
         doTest();
     }