[FE] Store receiver labels differently

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

@@ -6,6 +6,7 @@
 package org.jetbrains.kotlin.resolve;
 
 import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.Multimap;
 import com.intellij.openapi.util.Ref;
 import com.intellij.psi.PsiElement;
 import kotlin.Pair;
@@ -48,7 +49,6 @@ import org.jetbrains.kotlin.util.slicedMap.*;
 
 import java.util.Collection;
 import java.util.Collections;
-import java.util.Map;
 
 import static org.jetbrains.kotlin.util.slicedMap.RewritePolicy.DO_NOTHING;
 import static org.jetbrains.kotlin.util.slicedMap.Slices.COMPILE_TIME_VALUE_REWRITE_POLICY;
@@ -263,7 +263,7 @@ public interface BindingContext {
                     .setFurtherLookupSlices(DECLARATIONS_TO_DESCRIPTORS)
                     .build();
 
-    WritableSlice<DeclarationDescriptor, Map<ReceiverParameterDescriptor, String>> DESCRIPTOR_TO_NAMED_RECEIVERS = Slices.createSimpleSlice();
+    WritableSlice<DeclarationDescriptor, Multimap<String, ReceiverParameterDescriptor>> DESCRIPTOR_TO_NAMED_RECEIVERS = Slices.createSimpleSlice();
     WritableSlice<KtReferenceExpression, PsiElement> LABEL_TARGET = Slices.createSimpleSlice();
     WritableSlice<KtReferenceExpression, Collection<? extends PsiElement>> AMBIGUOUS_LABEL_TARGET = Slices.createSimpleSlice();
     WritableSlice<ValueParameterDescriptor, PropertyDescriptor> VALUE_PARAMETER_AS_PROPERTY = Slices.createSimpleSlice();

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

@@ -16,7 +16,9 @@
 
 package org.jetbrains.kotlin.resolve;
 
+import com.google.common.collect.HashMultimap;
 import com.google.common.collect.Lists;
+import com.google.common.collect.Multimap;
 import com.intellij.openapi.project.Project;
 import com.intellij.psi.PsiElement;
 import kotlin.Pair;
@@ -957,7 +959,7 @@ public class DescriptorResolver {
             }
         }
 
-        LinkedHashMap<ReceiverParameterDescriptor, String> receiverToLabelMap = new LinkedHashMap<>();
+        Multimap<String, ReceiverParameterDescriptor> nameToReceiverMap = HashMultimap.create();
 
         KtTypeReference receiverTypeRef = variableDeclaration.getReceiverTypeReference();
         ReceiverParameterDescriptor receiverDescriptor = null;
@@ -967,13 +969,16 @@ public class DescriptorResolver {
             receiverDescriptor = DescriptorFactory.createExtensionReceiverParameterForCallable(
                     propertyDescriptor, receiverType, splitter.getAnnotationsForTarget(RECEIVER)
             );
-            receiverToLabelMap.put(receiverDescriptor, receiverTypeRef.nameForReceiverLabel());
+            String receiverName = receiverTypeRef.nameForReceiverLabel();
+            if (receiverName != null) {
+                nameToReceiverMap.put(receiverName, receiverDescriptor);
+            }
         }
 
         List<KtContextReceiver> contextReceivers = variableDeclaration.getContextReceivers();
         List<ReceiverParameterDescriptor> contextReceiverDescriptors =
                 createReceiverDescriptorsForProperty(propertyDescriptor, scopeForDeclarationResolutionWithTypeParameters, trace,
-                                                     contextReceivers, receiverToLabelMap);
+                                                     contextReceivers, nameToReceiverMap);
 
         LexicalScope scopeForInitializer = ScopeUtils.makeScopeForPropertyInitializer(scopeForInitializerResolutionWithTypeParameters, propertyDescriptor);
         KotlinType propertyType = propertyInfo.getVariableType();
@@ -1022,7 +1027,7 @@ public class DescriptorResolver {
                 new FieldDescriptorImpl(annotationSplitter.getAnnotationsForTarget(FIELD), propertyDescriptor),
                 new FieldDescriptorImpl(annotationSplitter.getAnnotationsForTarget(PROPERTY_DELEGATE_FIELD), propertyDescriptor)
         );
-        trace.record(DESCRIPTOR_TO_NAMED_RECEIVERS, propertyDescriptor, receiverToLabelMap);
+        trace.record(DESCRIPTOR_TO_NAMED_RECEIVERS, propertyDescriptor, nameToReceiverMap);
         trace.record(BindingContext.VARIABLE, variableDeclaration, propertyDescriptor);
         return propertyDescriptor;
     }
@@ -1032,7 +1037,7 @@ public class DescriptorResolver {
             @NotNull LexicalScope scopeForResolution,
             @NotNull BindingTrace trace,
             @NotNull List<KtContextReceiver> contextReceivers,
-            @NotNull Map<ReceiverParameterDescriptor, String> receiverToLabelMap
+            @NotNull Multimap<String, ReceiverParameterDescriptor> labelNameToReceiverMap
     ) {
         Map<KtContextReceiver, KotlinType> contextReceiversToTypes = new LinkedHashMap<>();
         for (KtContextReceiver contextReceiver: contextReceivers) {
@@ -1051,7 +1056,7 @@ public class DescriptorResolver {
             );
             String contextReceiverName = contextReceiver.name();
             if (contextReceiverName != null) {
-                receiverToLabelMap.put(receiverDescriptor, contextReceiverName);
+                labelNameToReceiverMap.put(contextReceiverName, receiverDescriptor);
             }
             return receiverDescriptor;
         }).collect(Collectors.toList());

compiler/frontend/src/org/jetbrains/kotlin/resolve/FunctionDescriptorResolver.kt

@@ -16,6 +16,7 @@
 
 package org.jetbrains.kotlin.resolve
 
+import com.google.common.collect.HashMultimap
 import com.intellij.openapi.util.ThrowableComputable
 import com.intellij.psi.PsiElement
 import com.intellij.util.AstLoadingFilter
@@ -242,20 +243,20 @@ class FunctionDescriptorResolver(
         }
 
         if (languageVersionSettings.supportsFeature(LanguageFeature.ContextReceivers)) {
-            val receiverToLabelMap = linkedMapOf<ReceiverParameterDescriptor, String>()
+            val labelNameToReceiverMap = HashMultimap.create<String, ReceiverParameterDescriptor>()
             if (receiverTypeRef != null && extensionReceiver != null) {
                 receiverTypeRef.nameForReceiverLabel()?.let {
-                    receiverToLabelMap[extensionReceiver] = it
+                    labelNameToReceiverMap.put(it, extensionReceiver)
                 }
             }
             contextReceiverDescriptors.zip(0 until contextReceivers.size).reversed()
                 .forEach { (contextReceiverDescriptor, i) ->
                     contextReceivers[i].name()?.let {
-                        receiverToLabelMap[contextReceiverDescriptor] = it
+                        labelNameToReceiverMap.put(it, contextReceiverDescriptor)
                     }
                 }
 
-            trace.record(BindingContext.DESCRIPTOR_TO_NAMED_RECEIVERS, functionDescriptor, receiverToLabelMap)
+            trace.record(BindingContext.DESCRIPTOR_TO_NAMED_RECEIVERS, functionDescriptor, labelNameToReceiverMap)
         }
 
         functionDescriptor.initialize(

compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/smartcasts/IdentifierInfo.kt

@@ -316,13 +316,13 @@ private fun findReceiverByLabelOrGetDefault(
     bindingContext: BindingContext,
     labelName: String
 ): ReceiverParameterDescriptor {
-    val receiverToLabelMap = bindingContext.get(
+    val labelNameToReceiverMap = bindingContext.get(
         BindingContext.DESCRIPTOR_TO_NAMED_RECEIVERS,
         if (descriptorOfThisReceiver is PropertyAccessorDescriptor) descriptorOfThisReceiver.correspondingProperty else descriptorOfThisReceiver
     )
-    return receiverToLabelMap?.entries?.find {
-        it.value == labelName
-    }?.key ?: default ?: error("'This' refers to the callable member without a receiver parameter: $descriptorOfThisReceiver")
+    return labelNameToReceiverMap?.get(labelName)?.singleOrNull()
+        ?: default
+        ?: error("'This' refers to the callable member without a receiver parameter: $descriptorOfThisReceiver")
 }
 
 private fun postfix(argumentInfo: IdentifierInfo, op: KtToken): IdentifierInfo =

compiler/frontend/src/org/jetbrains/kotlin/types/expressions/LabelResolver.kt

@@ -183,15 +183,13 @@ object LabelResolver {
                 )
                 val declarationDescriptor = context.trace.bindingContext[DECLARATION_TO_DESCRIPTOR, element]
                 if (declarationDescriptor is FunctionDescriptor) {
-                    val receiverToLabelMap = context.trace.bindingContext[
+                    val labelNameToReceiverMap = context.trace.bindingContext[
                             DESCRIPTOR_TO_NAMED_RECEIVERS,
                             if (declarationDescriptor is PropertyAccessorDescriptor) declarationDescriptor.correspondingProperty else declarationDescriptor
                     ]
-                    val thisReceivers = receiverToLabelMap?.entries?.filter {
-                        it.value == labelName.identifier
-                    }?.map { it.key } ?: emptyList()
+                    val thisReceivers = labelNameToReceiverMap?.get(labelName.identifier)
                     val thisReceiver = when {
-                        thisReceivers.isEmpty() -> declarationDescriptor.extensionReceiverParameter
+                        thisReceivers == null -> declarationDescriptor.extensionReceiverParameter
                         thisReceivers.size == 1 -> thisReceivers.single()
                         else -> {
                             BindingContextUtils.reportAmbiguousLabel(context.trace, targetLabel, declarationsByLabel)