Replace 'addOverriddenDescriptor' with 'setOverriddenDescriptors'

It helps to get rid of redundant SmartSets (e.g. for top-level functions)

compiler/backend/src/org/jetbrains/kotlin/codegen/ClosureCodegen.java

@@ -195,7 +195,7 @@ public class ClosureCodegen extends MemberCodegen<KtElement> {
                                 erasedInterfaceFunction.getValueParameters(), erasedInterfaceFunction.getReturnType(),
                                 Modality.OPEN, erasedInterfaceFunction.getVisibility());
 
-            descriptorForBridges.addOverriddenDescriptor(erasedInterfaceFunction);
+            DescriptorUtilsKt.setSingleOverridden(descriptorForBridges, erasedInterfaceFunction);
             functionCodegen.generateBridges(descriptorForBridges);
         }
 

compiler/backend/src/org/jetbrains/kotlin/codegen/SamWrapperCodegen.java

@@ -30,6 +30,7 @@ import org.jetbrains.kotlin.name.FqName;
 import org.jetbrains.kotlin.name.Name;
 import org.jetbrains.kotlin.psi.KtFile;
 import org.jetbrains.kotlin.resolve.DescriptorUtils;
+import org.jetbrains.kotlin.resolve.descriptorUtil.DescriptorUtilsKt;
 import org.jetbrains.kotlin.resolve.jvm.diagnostics.JvmDeclarationOriginKt;
 import org.jetbrains.kotlin.types.KotlinType;
 import org.jetbrains.kotlin.util.OperatorNameConventions;
@@ -165,7 +166,7 @@ public class SamWrapperCodegen {
                             originalInterfaceErased.getValueParameters(), originalInterfaceErased.getReturnType(),
                             Modality.OPEN, originalInterfaceErased.getVisibility());
 
-        descriptorForBridges.addOverriddenDescriptor(originalInterfaceErased);
+        DescriptorUtilsKt.setSingleOverridden(descriptorForBridges, originalInterfaceErased);
         codegen.generateBridges(descriptorForBridges);
     }
 

compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/tasks/synthesizedInvokes.kt

@@ -25,6 +25,7 @@ import org.jetbrains.kotlin.descriptors.FunctionDescriptor
 import org.jetbrains.kotlin.descriptors.impl.SimpleFunctionDescriptorImpl
 import org.jetbrains.kotlin.descriptors.impl.ValueParameterDescriptorImpl
 import org.jetbrains.kotlin.name.Name
+import org.jetbrains.kotlin.resolve.descriptorUtil.setSingleOverridden
 import org.jetbrains.kotlin.types.TypeSubstitutor
 import org.jetbrains.kotlin.util.OperatorNameConventions
 import java.util.*
@@ -48,7 +49,7 @@ fun createSynthesizedInvokes(functions: Collection<FunctionDescriptor>): Collect
                     CallableMemberDescriptor.Kind.FAKE_OVERRIDE,
                     true
             )
-            fakeOverride.addOverriddenDescriptor(synthesizedSuperFun)
+            fakeOverride.setSingleOverridden(synthesizedSuperFun)
             fakeOverride
         }
 

core/descriptor.loader.java/src/org/jetbrains/kotlin/load/java/descriptors/JavaPropertyDescriptor.java

@@ -97,9 +97,7 @@ public class JavaPropertyDescriptor extends PropertyDescriptorImpl implements Ja
             enhanced.setCompileTimeInitializer(compileTimeInitializer);
         }
 
-        for (PropertyDescriptor descriptor : getOverriddenDescriptors()) {
+        enhanced.setOverriddenDescriptors(getOverriddenDescriptors());
-            enhanced.addOverriddenDescriptor(descriptor);
-        }
 
         enhanced.setType(
                 enhancedReturnType,

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

@@ -29,7 +29,7 @@ public interface CallableMemberDescriptor extends CallableDescriptor, MemberDesc
     @Override
     CallableMemberDescriptor getOriginal();
 
-    void addOverriddenDescriptor(@NotNull CallableMemberDescriptor overridden);
+    void setOverriddenDescriptors(@NotNull Collection<? extends CallableMemberDescriptor> overriddenDescriptors);
 
     enum Kind {
         DECLARATION,

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

@@ -123,8 +123,8 @@ public class ConstructorDescriptorImpl extends FunctionDescriptorImpl implements
     }
 
     @Override
-    public void addOverriddenDescriptor(@NotNull CallableMemberDescriptor overriddenFunction) {
+    public void setOverriddenDescriptors(@NotNull Collection<? extends CallableMemberDescriptor> overriddenDescriptors) {
-        throw new UnsupportedOperationException("Constructors cannot override anything");
+        assert overriddenDescriptors.isEmpty() : "Constructors cannot override anything";
     }
 
     @NotNull

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

@@ -29,10 +29,7 @@ import org.jetbrains.kotlin.types.Variance;
 import org.jetbrains.kotlin.utils.CollectionsKt;
 import org.jetbrains.kotlin.utils.SmartSet;
 
-import java.util.ArrayList;
+import java.util.*;
-import java.util.Collection;
-import java.util.List;
-import java.util.Set;
 
 public abstract class FunctionDescriptorImpl extends DeclarationDescriptorNonRootImpl implements FunctionDescriptor {
     private List<TypeParameterDescriptor> typeParameters;
@@ -50,7 +47,7 @@ public abstract class FunctionDescriptorImpl extends DeclarationDescriptorNonRoo
     private boolean isHidden = false;
     private boolean hasStableParameterNames = true;
     private boolean hasSynthesizedParameterNames = false;
-    private final Set<FunctionDescriptor> overriddenFunctions = SmartSet.create();
+    private Collection<? extends FunctionDescriptor> overriddenFunctions = null;
     private final FunctionDescriptor original;
     private final Kind kind;
     @Nullable
@@ -165,7 +162,7 @@ public abstract class FunctionDescriptorImpl extends DeclarationDescriptorNonRoo
     @NotNull
     @Override
     public Collection<? extends FunctionDescriptor> getOverriddenDescriptors() {
-        return overriddenFunctions;
+        return overriddenFunctions != null ? overriddenFunctions : Collections.<FunctionDescriptor>emptyList();
     }
 
     @NotNull
@@ -184,7 +181,7 @@ public abstract class FunctionDescriptorImpl extends DeclarationDescriptorNonRoo
     public boolean isOperator() {
         if (isOperator) return true;
 
-        for (FunctionDescriptor descriptor : overriddenFunctions) {
+        for (FunctionDescriptor descriptor : getOverriddenDescriptors()) {
             if (descriptor.isOperator()) return true;
         }
 
@@ -195,7 +192,7 @@ public abstract class FunctionDescriptorImpl extends DeclarationDescriptorNonRoo
     public boolean isInfix() {
         if (isInfix) return true;
 
-        for (FunctionDescriptor descriptor : overriddenFunctions) {
+        for (FunctionDescriptor descriptor : getOverriddenDescriptors()) {
             if (descriptor.isInfix()) return true;
         }
 
@@ -223,8 +220,9 @@ public abstract class FunctionDescriptorImpl extends DeclarationDescriptorNonRoo
     }
 
     @Override
-    public void addOverriddenDescriptor(@NotNull CallableMemberDescriptor overriddenFunction) {
+    public void setOverriddenDescriptors(@NotNull Collection<? extends CallableMemberDescriptor> overriddenDescriptors) {
-        overriddenFunctions.add((FunctionDescriptor) overriddenFunction);
+        //noinspection unchecked
+        overriddenFunctions = (Collection<? extends FunctionDescriptor>) overriddenDescriptors;
     }
 
     @Override
@@ -522,14 +520,16 @@ public abstract class FunctionDescriptorImpl extends DeclarationDescriptorNonRoo
             substitutedDescriptor.setInitialSignatureDescriptor(initialSignatureSubstituted);
         }
 
-        if (configuration.copyOverrides) {
+        if (configuration.copyOverrides && !getOverriddenDescriptors().isEmpty()) {
-            for (FunctionDescriptor overriddenFunction : overriddenFunctions) {
+            if (configuration.originalSubstitutor.isEmpty()) {
-                if (configuration.originalSubstitutor.isEmpty()) {
+                substitutedDescriptor.setOverriddenDescriptors(getOverriddenDescriptors());
-                    substitutedDescriptor.addOverriddenDescriptor(overriddenFunction);
+            }
-                }
+            else {
-                else {
+                Collection<CallableMemberDescriptor> substitutedOverridden = SmartSet.create();
-                    substitutedDescriptor.addOverriddenDescriptor(overriddenFunction.substitute(substitutor));
+                for (FunctionDescriptor overriddenFunction : getOverriddenDescriptors()) {
+                    substitutedOverridden.add(overriddenFunction.substitute(substitutor));
                 }
+                substitutedDescriptor.setOverriddenDescriptors(substitutedOverridden);
             }
         }
 

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

@@ -184,8 +184,8 @@ public abstract class PropertyAccessorDescriptorImpl extends DeclarationDescript
     }
 
     @Override
-    public void addOverriddenDescriptor(@NotNull CallableMemberDescriptor overridden) {
+    public void setOverriddenDescriptors(@NotNull Collection<? extends CallableMemberDescriptor> overriddenDescriptors) {
-        throw new IllegalStateException();
+        assert overriddenDescriptors.isEmpty() : "Overridden accessors should be empty";
     }
 
     @NotNull

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

@@ -36,7 +36,7 @@ import static org.jetbrains.kotlin.resolve.descriptorUtil.DescriptorUtilsKt.getB
 public class PropertyDescriptorImpl extends VariableDescriptorWithInitializerImpl implements PropertyDescriptor {
     private final Modality modality;
     private Visibility visibility;
-    private final Set<PropertyDescriptor> overriddenProperties = SmartSet.create();
+    private Collection<? extends PropertyDescriptor> overriddenProperties = null;
     private final PropertyDescriptor original;
     private final Kind kind;
     private final boolean lateInit;
@@ -295,9 +295,11 @@ public class PropertyDescriptorImpl extends VariableDescriptorWithInitializerImp
         substitutedDescriptor.initialize(newGetter, newSetter);
 
         if (copyOverrides) {
-            for (PropertyDescriptor propertyDescriptor : overriddenProperties) {
+            Collection<CallableMemberDescriptor> overridden = SmartSet.create();
-                substitutedDescriptor.addOverriddenDescriptor(propertyDescriptor.substitute(substitutor));
+            for (PropertyDescriptor propertyDescriptor : getOverriddenDescriptors()) {
+                overridden.add(propertyDescriptor.substitute(substitutor));
             }
+            substitutedDescriptor.setOverriddenDescriptors(overridden);
         }
 
         return substitutedDescriptor;
@@ -353,14 +355,15 @@ public class PropertyDescriptorImpl extends VariableDescriptorWithInitializerImp
     }
 
     @Override
-    public void addOverriddenDescriptor(@NotNull CallableMemberDescriptor overridden) {
+    public void setOverriddenDescriptors(@NotNull Collection<? extends CallableMemberDescriptor> overriddenDescriptors) {
-        overriddenProperties.add((PropertyDescriptorImpl) overridden);
+        //noinspection unchecked
+        this.overriddenProperties = (Collection<? extends PropertyDescriptor>) overriddenDescriptors;
     }
 
     @NotNull
     @Override
     public Collection<? extends PropertyDescriptor> getOverriddenDescriptors() {
-        return overriddenProperties;
+        return overriddenProperties != null ? overriddenProperties : Collections.<PropertyDescriptor>emptyList();
     }
 
     @NotNull

core/descriptors/src/org/jetbrains/kotlin/resolve/DescriptorUtils.kt

@@ -230,3 +230,7 @@ fun CallableMemberDescriptor.firstOverridden(
                    }
     )
 }
+
+fun CallableMemberDescriptor.setSingleOverridden(overridden: CallableMemberDescriptor) {
+    overriddenDescriptors = listOf(overridden)
+}

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

@@ -31,6 +31,7 @@ import org.jetbrains.kotlin.types.FlexibleTypesKt;
 import org.jetbrains.kotlin.types.KotlinType;
 import org.jetbrains.kotlin.types.TypeConstructor;
 import org.jetbrains.kotlin.types.checker.KotlinTypeChecker;
+import org.jetbrains.kotlin.utils.SmartSet;
 
 import java.util.*;
 
@@ -293,6 +294,7 @@ public class OverridingUtil {
             @NotNull DescriptorSink sink
     ) {
         Collection<CallableMemberDescriptor> bound = new ArrayList<CallableMemberDescriptor>(descriptorsFromSuper.size());
+        Collection<CallableMemberDescriptor> overridden = SmartSet.create();
         for (CallableMemberDescriptor fromSupertype : descriptorsFromSuper) {
             OverrideCompatibilityInfo.Result result = DEFAULT.isOverridableBy(fromSupertype, fromCurrent, current).getResult();
 
@@ -300,7 +302,7 @@ public class OverridingUtil {
             switch (result) {
                 case OVERRIDABLE:
                     if (isVisible) {
-                        fromCurrent.addOverriddenDescriptor(fromSupertype);
+                        overridden.add(fromSupertype);
                     }
                     bound.add(fromSupertype);
                     break;
@@ -314,6 +316,9 @@ public class OverridingUtil {
                     break;
             }
         }
+
+        fromCurrent.setOverriddenDescriptors(overridden);
+
         return bound;
     }
 
@@ -496,9 +501,7 @@ public class OverridingUtil {
                                          });
         CallableMemberDescriptor fakeOverride =
                 mostSpecific.copy(current, modality, visibility, CallableMemberDescriptor.Kind.FAKE_OVERRIDE, false);
-        for (CallableMemberDescriptor descriptor : effectiveOverridden) {
+        fakeOverride.setOverriddenDescriptors(effectiveOverridden);
-            fakeOverride.addOverriddenDescriptor(descriptor);
-        }
         sink.addFakeOverride(fakeOverride);
     }
 

core/descriptors/src/org/jetbrains/kotlin/types/error/ErrorSimpleFunctionDescriptorImpl.java

@@ -25,6 +25,7 @@ import org.jetbrains.kotlin.descriptors.impl.SimpleFunctionDescriptorImpl;
 import org.jetbrains.kotlin.name.Name;
 import org.jetbrains.kotlin.types.ErrorUtils;
 
+import java.util.Collection;
 import java.util.List;
 
 public class ErrorSimpleFunctionDescriptorImpl extends SimpleFunctionDescriptorImpl {
@@ -80,7 +81,7 @@ public class ErrorSimpleFunctionDescriptorImpl extends SimpleFunctionDescriptorI
     }
 
     @Override
-    public void addOverriddenDescriptor(@NotNull CallableMemberDescriptor overriddenFunction) {
+    public void setOverriddenDescriptors(@NotNull Collection<? extends CallableMemberDescriptor> overriddenDescriptors) {
         // nop
     }
 }

idea/idea-core/src/org/jetbrains/kotlin/idea/core/overrideImplement/OverrideMemberChooserObject.kt

@@ -28,6 +28,7 @@ import org.jetbrains.kotlin.idea.core.util.DescriptorMemberChooserObject
 import org.jetbrains.kotlin.idea.util.IdeDescriptorRenderers
 import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.renderer.*
+import org.jetbrains.kotlin.resolve.descriptorUtil.setSingleOverridden
 
 interface OverrideMemberChooserObject : ClassMember {
     enum class BodyType {
@@ -108,7 +109,7 @@ private val OVERRIDE_RENDERER = DescriptorRenderer.withOptions {
 private fun generateProperty(project: Project, descriptor: PropertyDescriptor, bodyType: OverrideMemberChooserObject.BodyType): KtProperty {
     val newDescriptor = descriptor.copy(descriptor.containingDeclaration, Modality.OPEN, descriptor.visibility,
                                         descriptor.kind, /* copyOverrides = */ true) as PropertyDescriptor
-    newDescriptor.addOverriddenDescriptor(descriptor)
+    newDescriptor.setSingleOverridden(descriptor)
 
     val body = buildString {
         append("\nget()")
@@ -124,14 +125,14 @@ private fun generateProperty(project: Project, descriptor: PropertyDescriptor, b
 private fun generateConstructorParameter(project: Project, descriptor: PropertyDescriptor): KtParameter {
     val newDescriptor = descriptor.copy(descriptor.containingDeclaration, Modality.OPEN, descriptor.visibility,
                                         descriptor.kind, /* copyOverrides = */ true) as PropertyDescriptor
-    newDescriptor.addOverriddenDescriptor(descriptor)
+    newDescriptor.setSingleOverridden(descriptor)
     return KtPsiFactory(project).createParameter(OVERRIDE_RENDERER.render(newDescriptor))
 }
 
 private fun generateFunction(project: Project, descriptor: FunctionDescriptor, bodyType: OverrideMemberChooserObject.BodyType): KtNamedFunction {
     val newDescriptor = descriptor.copy(descriptor.containingDeclaration, Modality.OPEN, descriptor.visibility,
                                         descriptor.kind, /* copyOverrides = */ true)
-    newDescriptor.addOverriddenDescriptor(descriptor)
+    newDescriptor.setSingleOverridden(descriptor)
 
     val returnType = descriptor.returnType
     val returnsNotUnit = returnType != null && !KotlinBuiltIns.isUnit(returnType)

idea/src/org/jetbrains/kotlin/idea/quickfix/ChangeMemberFunctionSignatureFix.kt

@@ -40,6 +40,7 @@ import org.jetbrains.kotlin.psi.KtPsiFactory
 import org.jetbrains.kotlin.renderer.DescriptorRenderer
 import org.jetbrains.kotlin.renderer.NameShortness
 import org.jetbrains.kotlin.resolve.FunctionDescriptorUtil
+import org.jetbrains.kotlin.resolve.descriptorUtil.setSingleOverridden
 import org.jetbrains.kotlin.resolve.findMemberWithMaxVisibility
 import org.jetbrains.kotlin.types.checker.KotlinTypeChecker
 import org.jetbrains.kotlin.types.typeUtil.supertypes
@@ -129,7 +130,7 @@ class ChangeMemberFunctionSignatureFix private constructor(
                             CallableMemberDescriptor.Kind.DELEGATION,
                             /* copyOverrides = */ true),
                     newParameters)
-            newFunction.addOverriddenDescriptor(superFunction)
+            newFunction.setSingleOverridden(superFunction)
 
             return Signature(newFunction)
         }