Write to trace in case class qualifier is a short reference to default object

This allows to fix some cases when there is a difference between explicit and short reference to default object
Fix shorten reference, optimize imports and import insert helper for default objects
ShortenReferences always transforms default object references to shorter form for now
Fix DescriptorUtils#getFqName() for default objects (affects test data mostly)
Fix DescriptorUtils#getImportableDescriptor()

compiler/frontend/src/org/jetbrains/kotlin/resolve/BindingContext.java

@@ -96,6 +96,9 @@ public interface BindingContext {
 
     WritableSlice<JetReferenceExpression, DeclarationDescriptor> REFERENCE_TARGET =
             new BasicWritableSlice<JetReferenceExpression, DeclarationDescriptor>(DO_NOTHING);
+    // if 'A' really means 'A.Default' then this slice stores class descriptor for A, REFERENCE_TARGET stores descriptor Default in this case
+    WritableSlice<JetReferenceExpression, ClassDescriptor> SHORT_REFERENCE_TO_DEFAULT_OBJECT =
+            new BasicWritableSlice<JetReferenceExpression, ClassDescriptor>(DO_NOTHING);
 
     @KotlinSignature("val RESOLVED_CALL: WritableSlice<Call, ResolvedCall<out CallableDescriptor>>")
     WritableSlice<Call, ResolvedCall<?>> RESOLVED_CALL = new BasicWritableSlice<Call, ResolvedCall<?>>(DO_NOTHING);

compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/tasks/TracingStrategyImpl.java

@@ -58,7 +58,11 @@ public class TracingStrategyImpl extends AbstractTracingStrategy {
             descriptor = ((VariableAsFunctionResolvedCall) resolvedCall).getVariableCall().getCandidateDescriptor();
         }
         if (descriptor instanceof FakeCallableDescriptorForObject) {
-            descriptor = ((FakeCallableDescriptorForObject) descriptor).getReferencedDescriptor();
+            FakeCallableDescriptorForObject fakeCallableDescriptorForObject = (FakeCallableDescriptorForObject) descriptor;
+            descriptor = fakeCallableDescriptorForObject.getReferencedDescriptor();
+            if (fakeCallableDescriptorForObject.getClassDescriptor().getDefaultObjectDescriptor() != null) {
+                trace.record(SHORT_REFERENCE_TO_DEFAULT_OBJECT, reference, fakeCallableDescriptorForObject.getClassDescriptor());
+            }
         }
         DeclarationDescriptor storedReference = trace.get(REFERENCE_TARGET, reference);
         if (storedReference == null || !ErrorUtils.isError(descriptor)) {

compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/util/FakeCallableDescriptorForObject.kt

@@ -30,7 +30,7 @@ import org.jetbrains.kotlin.descriptors.SourceElement
 import org.jetbrains.kotlin.resolve.descriptorUtil.getClassObjectReferenceTarget
 
 public class FakeCallableDescriptorForObject(
-        private val classDescriptor: ClassDescriptor
+        public val classDescriptor: ClassDescriptor
 ) : DeclarationDescriptorWithVisibility by classDescriptor.getClassObjectReferenceTarget(), VariableDescriptor {
 
     {

compiler/frontend/src/org/jetbrains/kotlin/resolve/scopes/receivers/Qualifier.kt

@@ -148,11 +148,14 @@ private fun QualifierReceiver.resolveAsReceiverInQualifiedExpression(context: Ex
 }
 
 private fun QualifierReceiver.resolveAndRecordReferenceTarget(context: ExpressionTypingContext, selector: DeclarationDescriptor?) {
-    resultingDescriptor = resolveReferenceTarget(selector)
+    resultingDescriptor = resolveReferenceTarget(context, selector)
     context.trace.record(REFERENCE_TARGET, referenceExpression, resultingDescriptor)
 }
 
-private fun QualifierReceiver.resolveReferenceTarget(selector: DeclarationDescriptor?): DeclarationDescriptor {
+private fun QualifierReceiver.resolveReferenceTarget(
+        context: ExpressionTypingContext,
+        selector: DeclarationDescriptor?
+): DeclarationDescriptor {
     if (classifier is TypeParameterDescriptor) {
         return classifier
     }
@@ -168,6 +171,9 @@ private fun QualifierReceiver.resolveReferenceTarget(selector: DeclarationDescri
     }
 
     if (classifier is ClassDescriptor && classifier.classObjectDescriptor == selectorContainer) {
+        if (classifier.getDefaultObjectDescriptor() != null) {
+            context.trace.record(SHORT_REFERENCE_TO_DEFAULT_OBJECT, referenceExpression, classifier)
+        }
         return classifier.getClassObjectReferenceTarget()
     }
 

compiler/testData/diagnostics/tests/classObjects/importClassInClassObject.txt

@@ -1,7 +1,7 @@
 package
 
 package f {
-    internal fun test(): f.A.B
+    internal fun test(): f.A.Default.B
 
     internal final class A {
         public constructor A()

compiler/testData/diagnostics/tests/classObjects/nestedClassInPrivateClassObject.txt

@@ -1,6 +1,6 @@
 package
 
-internal fun f1(): A.B.C.Default
+internal fun f1(): A.Default.B.C.Default
 internal fun f2(): kotlin.Unit
 
 internal final class A {

compiler/testData/diagnostics/tests/enum/inner/insideClassObject.txt

@@ -12,10 +12,10 @@ internal final class A {
         public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
         public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
 
-        internal final enum class E : kotlin.Enum<A.E> {
-            public enum entry ENTRY : A.E {
+        internal final enum class E : kotlin.Enum<A.Default.E> {
+            public enum entry ENTRY : A.Default.E {
                 private constructor ENTRY()
-                public final override /*1*/ /*fake_override*/ fun compareTo(/*0*/ other: A.E): kotlin.Int
+                public final override /*1*/ /*fake_override*/ fun compareTo(/*0*/ other: A.Default.E): kotlin.Int
                 public final override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
                 public final override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
                 public final override /*1*/ /*fake_override*/ fun name(): kotlin.String
@@ -24,7 +24,7 @@ internal final class A {
             }
 
             private constructor E()
-            public final override /*1*/ /*fake_override*/ fun compareTo(/*0*/ other: A.E): kotlin.Int
+            public final override /*1*/ /*fake_override*/ fun compareTo(/*0*/ other: A.Default.E): kotlin.Int
             public final override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
             public final override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
             public final override /*1*/ /*fake_override*/ fun name(): kotlin.String
@@ -32,8 +32,8 @@ internal final class A {
             public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
 
             // Static members
-            public final /*synthesized*/ fun valueOf(/*0*/ value: kotlin.String): A.E
-            public final /*synthesized*/ fun values(): kotlin.Array<A.E>
+            public final /*synthesized*/ fun valueOf(/*0*/ value: kotlin.String): A.Default.E
+            public final /*synthesized*/ fun values(): kotlin.Array<A.Default.E>
         }
     }
 }

compiler/testData/diagnostics/tests/enum/inner/redeclarationInClassObject.txt

@@ -12,10 +12,10 @@ internal final class A {
         public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
         public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
 
-        internal final enum class E : kotlin.Enum<A.E> {
-            public enum entry ENTRY2 : A.E {
+        internal final enum class E : kotlin.Enum<A.Default.E> {
+            public enum entry ENTRY2 : A.Default.E {
                 private constructor ENTRY2()
-                public final override /*1*/ /*fake_override*/ fun compareTo(/*0*/ other: A.E): kotlin.Int
+                public final override /*1*/ /*fake_override*/ fun compareTo(/*0*/ other: A.Default.E): kotlin.Int
                 public final override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
                 public final override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
                 public final override /*1*/ /*fake_override*/ fun name(): kotlin.String
@@ -24,7 +24,7 @@ internal final class A {
             }
 
             private constructor E()
-            public final override /*1*/ /*fake_override*/ fun compareTo(/*0*/ other: A.E): kotlin.Int
+            public final override /*1*/ /*fake_override*/ fun compareTo(/*0*/ other: A.Default.E): kotlin.Int
             public final override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
             public final override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
             public final override /*1*/ /*fake_override*/ fun name(): kotlin.String
@@ -32,8 +32,8 @@ internal final class A {
             public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
 
             // Static members
-            public final /*synthesized*/ fun valueOf(/*0*/ value: kotlin.String): A.E
-            public final /*synthesized*/ fun values(): kotlin.Array<A.E>
+            public final /*synthesized*/ fun valueOf(/*0*/ value: kotlin.String): A.Default.E
+            public final /*synthesized*/ fun values(): kotlin.Array<A.Default.E>
         }
     }
 

compiler/testData/diagnostics/tests/enum/inner/twoEnumsInClassObjectAndInnerClass.txt

@@ -43,10 +43,10 @@ internal final class A {
         public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
         public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
 
-        internal final enum class E : kotlin.Enum<A.E> {
-            public enum entry ENTRY : A.E {
+        internal final enum class E : kotlin.Enum<A.Default.E> {
+            public enum entry ENTRY : A.Default.E {
                 private constructor ENTRY()
-                public final override /*1*/ /*fake_override*/ fun compareTo(/*0*/ other: A.E): kotlin.Int
+                public final override /*1*/ /*fake_override*/ fun compareTo(/*0*/ other: A.Default.E): kotlin.Int
                 public final override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
                 public final override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
                 public final override /*1*/ /*fake_override*/ fun name(): kotlin.String
@@ -55,7 +55,7 @@ internal final class A {
             }
 
             private constructor E()
-            public final override /*1*/ /*fake_override*/ fun compareTo(/*0*/ other: A.E): kotlin.Int
+            public final override /*1*/ /*fake_override*/ fun compareTo(/*0*/ other: A.Default.E): kotlin.Int
             public final override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
             public final override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
             public final override /*1*/ /*fake_override*/ fun name(): kotlin.String
@@ -63,8 +63,8 @@ internal final class A {
             public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
 
             // Static members
-            public final /*synthesized*/ fun valueOf(/*0*/ value: kotlin.String): A.E
-            public final /*synthesized*/ fun values(): kotlin.Array<A.E>
+            public final /*synthesized*/ fun valueOf(/*0*/ value: kotlin.String): A.Default.E
+            public final /*synthesized*/ fun values(): kotlin.Array<A.Default.E>
         }
     }
 }

compiler/testData/diagnostics/tests/imports/Imports.txt

@@ -81,8 +81,8 @@ package c {
 }
 
 package d {
-    internal val b: d.A.B
-    internal val c: d.A.B
+    internal val b: d.A.Default.B
+    internal val c: d.A.Default.B
 
     internal final class A {
         public constructor A()
@@ -103,7 +103,7 @@ package d {
                 public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
             }
 
-            internal object C : d.A.B {
+            internal object C : d.A.Default.B {
                 private constructor C()
                 public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
                 public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int

compiler/testData/diagnostics/tests/inner/selfAnnotationForClassObject.txt

@@ -6,7 +6,7 @@ internal final class Test {
     public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
     public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
 
-    Test.ClassObjectAnnotation() Test.NestedAnnotation() internal class object Default {
+    Test.Default.ClassObjectAnnotation() Test.NestedAnnotation() internal class object Default {
         private constructor Default()
         public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
         public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int

compiler/testData/diagnostics/tests/multimodule/duplicateClass/duplicateNestedClasses.kt

@@ -64,5 +64,5 @@ fun test(m1: M1) {
     d(m1.d)
     e(m1.e)
     f(m1.f)
-    g(m1.g)
+    g(<!TYPE_MISMATCH!>m1.g<!>)
 }

compiler/testData/diagnostics/tests/multimodule/duplicateClass/duplicateNestedClasses.txt

@@ -64,10 +64,10 @@ package p {
         public final val a: p.A
         public final val b: p.A.B
         public final val c: p.A.C
-        public final val d: p.A.D
-        public final val e: p.A.D.E
+        public final val d: p.A.Default.D
+        public final val e: p.A.Default.D.E
         public final val f: p.A.F
-        public final val g: p.A.G
+        public final val g: p.A.Default.G
         public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
         public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
         public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
@@ -82,8 +82,8 @@ package p {
     public fun a(/*0*/ p: p.A): kotlin.Unit
     public fun b(/*0*/ p: p.A.B): kotlin.Unit
     public fun c(/*0*/ p: p.A.C): kotlin.Unit
-    public fun d(/*0*/ p: p.A.D): kotlin.Unit
-    public fun e(/*0*/ p: p.A.D.E): kotlin.Unit
+    public fun d(/*0*/ p: p.A.Default.D): kotlin.Unit
+    public fun e(/*0*/ p: p.A.Default.D.E): kotlin.Unit
     public fun f(/*0*/ p: p.A.F): kotlin.Unit
     public fun g(/*0*/ p: p.A.G): kotlin.Unit
 
@@ -154,8 +154,8 @@ package p {
     public fun a(/*0*/ p: p.A): kotlin.Unit
     public fun b(/*0*/ p: p.A.B): kotlin.Unit
     public fun c(/*0*/ p: p.A.C): kotlin.Unit
-    public fun d(/*0*/ p: p.A.D): kotlin.Unit
-    public fun e(/*0*/ p: p.A.D.E): kotlin.Unit
+    public fun d(/*0*/ p: p.A.Default.D): kotlin.Unit
+    public fun e(/*0*/ p: p.A.Default.D.E): kotlin.Unit
     public fun f(/*0*/ p: p.A.F): kotlin.Unit
     public fun g(/*0*/ p: p.A.G): kotlin.Unit
 

compiler/testData/diagnostics/tests/regressions/kt394.txt

@@ -2,7 +2,7 @@ package
 
 internal final class X {
     public constructor X()
-    internal final val y: X.Y
+    internal final val y: X.Default.Y
     public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
     public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
     public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String

compiler/testData/diagnostics/tests/scopes/kt587.txt

@@ -20,7 +20,7 @@ internal final class Main {
 
             internal class object Default {
                 private constructor Default()
-                public final val N: Main.States
+                public final val N: Main.Default.States
                 public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
                 public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
                 public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String

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

@@ -20,6 +20,6 @@ internal final class A {
     }
 }
 
-test.A.Anno1() test.A.B.Anno2() internal final class C {
+test.A.Default.Anno1() test.A.Default.B.Anno2() internal final class C {
     /*primary*/ public constructor C()
 }

compiler/testData/loadJava/compiledKotlin/fromLoadJava/classObjectAnnotation.txt

@@ -3,7 +3,7 @@ package test
 internal final class Some {
     /*primary*/ public constructor Some()
 
-    test.Some.TestAnnotation() internal class object Default {
+    test.Some.Default.TestAnnotation() internal class object Default {
         /*primary*/ private constructor Default()
 
         internal final annotation class TestAnnotation : kotlin.Annotation {