Discover class objects for light class generation in the compiler

#KT-3337 In Progress
LightClasses: class object's property getter unresolved in Java, but compiles OK

compiler/cli/src/org/jetbrains/jet/cli/jvm/compiler/CliLightClassGenerationSupport.java

@@ -33,10 +33,9 @@ import org.jetbrains.jet.asJava.LightClassGenerationSupport;
 import org.jetbrains.jet.lang.descriptors.ClassDescriptor;
 import org.jetbrains.jet.lang.descriptors.DeclarationDescriptor;
 import org.jetbrains.jet.lang.descriptors.NamespaceDescriptor;
-import org.jetbrains.jet.lang.psi.JetClassOrObject;
+import org.jetbrains.jet.lang.psi.*;
-import org.jetbrains.jet.lang.psi.JetDeclaration;
-import org.jetbrains.jet.lang.psi.JetFile;
 import org.jetbrains.jet.lang.resolve.*;
+import org.jetbrains.jet.lang.resolve.java.JvmAbi;
 import org.jetbrains.jet.lang.resolve.name.FqName;
 
 import java.util.Collection;
@@ -95,6 +94,25 @@ public class CliLightClassGenerationSupport extends LightClassGenerationSupport
                 return Collections.singletonList((JetClassOrObject) element);
             }
         }
+
+        if (JvmAbi.isClassObjectFqName(fqName)) {
+            Collection<JetClassOrObject> parentClasses = findClassOrObjectDeclarations(fqName.parent(), searchScope);
+            return ContainerUtil.mapNotNull(parentClasses,
+                                            new Function<JetClassOrObject, JetClassOrObject>() {
+                                                @Override
+                                                public JetClassOrObject fun(JetClassOrObject classOrObject) {
+                                                    if (classOrObject instanceof JetClass) {
+                                                        JetClass jetClass = (JetClass) classOrObject;
+                                                        JetClassObject classObject = jetClass.getClassObject();
+                                                        if (classObject != null) {
+                                                            return classObject.getObjectDeclaration();
+                                                        }
+                                                    }
+                                                    return null;
+                                                }
+                                            });
+        }
+
         return Collections.emptyList();
     }
 

compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/JvmAbi.java

@@ -16,6 +16,10 @@
 
 package org.jetbrains.jet.lang.resolve.java;
 
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.jet.lang.resolve.name.FqName;
+import org.jetbrains.jet.lang.resolve.name.Name;
+
 public class JvmAbi {
     /**
      * This constant is used to identify binary format (class file) versions
@@ -39,6 +43,10 @@ public class JvmAbi {
     public static final JvmClassName JETBRAINS_NOT_NULL_ANNOTATION =
             JvmClassName.byFqNameWithoutInnerClasses("org.jetbrains.annotations.NotNull");
 
+    public static boolean isClassObjectFqName(@NotNull FqName fqName) {
+        return fqName.lastSegmentIs(Name.identifier(CLASS_OBJECT_CLASS_NAME));
+    }
+
     private JvmAbi() {
     }
 }

compiler/testData/asJava/lightClasses/ClassObject.kt

@@ -0,0 +1,6 @@
+package test
+
+class WithClassObject {
+  class object {
+  }
+}

compiler/tests/org/jetbrains/jet/asJava/KotlinLightClassCoherenceTest.java

@@ -36,7 +36,8 @@ public class KotlinLightClassCoherenceTest extends KotlinAsJavaTestBase {
     protected List<File> getKotlinSourceRoots() {
         return Lists.newArrayList(
                 new File("compiler/testData/asJava/lightClasses/Declared.kt"),
-                new File("compiler/testData/asJava/lightClasses/Package.kt")
+                new File("compiler/testData/asJava/lightClasses/Package.kt"),
+                new File("compiler/testData/asJava/lightClasses/ClassObject.kt")
         );
     }
 
@@ -48,7 +49,7 @@ public class KotlinLightClassCoherenceTest extends KotlinAsJavaTestBase {
     @NotNull
     protected PsiClass doTest(String qualifiedName) {
         KotlinLightClass psiClass = (KotlinLightClass) finder.findClass(qualifiedName, GlobalSearchScope.allScope(getProject()));
-        assertNotNull(psiClass);
+        assertNotNull("Class not found: " + qualifiedName, psiClass);
 
         Asserter asserter = new Asserter();
 
@@ -203,4 +204,8 @@ public class KotlinLightClassCoherenceTest extends KotlinAsJavaTestBase {
     public void testDeprecatedWithBracketsFQNSpaces() throws Exception {
         doTest();
     }
+
+    public void testClassObject() throws Exception {
+        doTest("test.WithClassObject.object");
+    }
 }