Don't store overridden descriptors in ValueParameterDescriptor

Compute it on each access instead, because it's too costly and not really
needed to store a LinkedHashSet for each parameter. Also inline
'bindFakeOverride'

core/descriptors/src/org/jetbrains/kotlin/descriptors/ValueParameterDescriptor.java

@@ -59,6 +59,4 @@ public interface ValueParameterDescriptor extends VariableDescriptor, ParameterD
     @NotNull
     @Override
     Set<? extends ValueParameterDescriptor> getOverriddenDescriptors();
-
-    void addOverriddenDescriptor(@NotNull ValueParameterDescriptor overridden);
 }

core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/FunctionDescriptorImpl.java

@@ -22,7 +22,6 @@ import org.jetbrains.kotlin.descriptors.*;
 import org.jetbrains.kotlin.descriptors.annotations.Annotations;
 import org.jetbrains.kotlin.name.Name;
 import org.jetbrains.kotlin.resolve.DescriptorFactory;
-import org.jetbrains.kotlin.resolve.OverridingUtil;
 import org.jetbrains.kotlin.types.DescriptorSubstitutor;
 import org.jetbrains.kotlin.types.JetType;
 import org.jetbrains.kotlin.types.TypeSubstitutor;
@@ -278,11 +277,13 @@ public abstract class FunctionDescriptorImpl extends DeclarationDescriptorNonRoo
                 newModality,
                 newVisibility
         );
+
         if (copyOverrides) {
             for (FunctionDescriptor overriddenFunction : overriddenFunctions) {
-                OverridingUtil.bindOverride(substitutedDescriptor, overriddenFunction.substitute(substitutor));
+                substitutedDescriptor.addOverriddenDescriptor(overriddenFunction.substitute(substitutor));
             }
         }
+
         return substitutedDescriptor;
     }
 

core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/PropertyDescriptorImpl.java

@@ -23,7 +23,6 @@ import org.jetbrains.kotlin.descriptors.*;
 import org.jetbrains.kotlin.descriptors.annotations.Annotations;
 import org.jetbrains.kotlin.name.Name;
 import org.jetbrains.kotlin.resolve.DescriptorFactory;
-import org.jetbrains.kotlin.resolve.OverridingUtil;
 import org.jetbrains.kotlin.types.DescriptorSubstitutor;
 import org.jetbrains.kotlin.types.JetType;
 import org.jetbrains.kotlin.types.TypeSubstitutor;
@@ -273,7 +272,7 @@ public class PropertyDescriptorImpl extends VariableDescriptorWithInitializerImp
 
         if (copyOverrides) {
             for (PropertyDescriptor propertyDescriptor : overriddenProperties) {
-                OverridingUtil.bindOverride(substitutedDescriptor, propertyDescriptor.substitute(substitutor));
+                substitutedDescriptor.addOverriddenDescriptor(propertyDescriptor.substitute(substitutor));
             }
         }
 

core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/ValueParameterDescriptorImpl.java

@@ -16,6 +16,8 @@
 
 package org.jetbrains.kotlin.descriptors.impl;
 
+import kotlin.KotlinPackage;
+import kotlin.jvm.functions.Function1;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.jetbrains.kotlin.descriptors.*;
@@ -26,7 +28,6 @@ import org.jetbrains.kotlin.types.JetType;
 import org.jetbrains.kotlin.types.TypeSubstitutor;
 
 import java.util.Collections;
-import java.util.LinkedHashSet;
 import java.util.Set;
 
 public class ValueParameterDescriptorImpl extends VariableDescriptorImpl implements ValueParameterDescriptor {
@@ -34,7 +35,6 @@ public class ValueParameterDescriptorImpl extends VariableDescriptorImpl impleme
     private final JetType varargElementType;
     private final int index;
     private final ValueParameterDescriptor original;
-    private final Set<ValueParameterDescriptor> overriddenDescriptors = new LinkedHashSet<ValueParameterDescriptor>(); // Linked is essential
 
     public ValueParameterDescriptorImpl(
             @NotNull CallableDescriptor containingDeclaration,
@@ -123,11 +123,14 @@ public class ValueParameterDescriptorImpl extends VariableDescriptorImpl impleme
     @NotNull
     @Override
     public Set<? extends ValueParameterDescriptor> getOverriddenDescriptors() {
-        return Collections.unmodifiableSet(overriddenDescriptors);
+        Set<? extends CallableDescriptor> overriddenFunctions = getContainingDeclaration().getOverriddenDescriptors();
-    }
+        if (overriddenFunctions.isEmpty()) return Collections.emptySet();
 
-    @Override
+        return KotlinPackage.toSet(KotlinPackage.map(overriddenFunctions, new Function1<CallableDescriptor, ValueParameterDescriptor>() {
-    public void addOverriddenDescriptor(@NotNull ValueParameterDescriptor overridden) {
+            @Override
-        overriddenDescriptors.add(overridden);
+            public ValueParameterDescriptor invoke(CallableDescriptor descriptor) {
+                return descriptor.getValueParameters().get(getIndex());
+            }
+        }));
     }
 }

core/descriptors/src/org/jetbrains/kotlin/resolve/OverridingUtil.java

@@ -230,17 +230,6 @@ public class OverridingUtil {
         }
     }
 
-    public static void bindOverride(CallableMemberDescriptor fromCurrent, CallableMemberDescriptor fromSupertype) {
-        fromCurrent.addOverriddenDescriptor(fromSupertype);
-
-        for (ValueParameterDescriptor parameterFromCurrent : fromCurrent.getValueParameters()) {
-            assert parameterFromCurrent.getIndex() < fromSupertype.getValueParameters().size()
-                    : "An override relation between functions implies that they have the same number of value parameters";
-            ValueParameterDescriptor parameterFromSupertype = fromSupertype.getValueParameters().get(parameterFromCurrent.getIndex());
-            parameterFromCurrent.addOverriddenDescriptor(parameterFromSupertype);
-        }
-    }
-
     public static void generateOverridesInFunctionGroup(
             @SuppressWarnings("UnusedParameters")
             @NotNull Name name, //DO NOT DELETE THIS PARAMETER: needed to make sure all descriptors have the same name
@@ -274,7 +263,7 @@ public class OverridingUtil {
             switch (result) {
                 case OVERRIDABLE:
                     if (isVisible) {
-                        bindOverride(fromCurrent, fromSupertype);
+                        fromCurrent.addOverriddenDescriptor(fromSupertype);
                     }
                     bound.add(fromSupertype);
                     break;
@@ -354,7 +343,7 @@ public class OverridingUtil {
         CallableMemberDescriptor fakeOverride =
                 mostSpecific.copy(current, modality, visibility, CallableMemberDescriptor.Kind.FAKE_OVERRIDE, false);
         for (CallableMemberDescriptor descriptor : effectiveOverridden) {
-            bindOverride(fakeOverride, descriptor);
+            fakeOverride.addOverriddenDescriptor(descriptor);
         }
         sink.addFakeOverride(fakeOverride);
     }