FIR: Simplify delegating constructors call resolution

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/tower/FirTowerResolver.kt

@@ -7,7 +7,11 @@ package org.jetbrains.kotlin.fir.resolve.calls.tower
 
 import org.jetbrains.kotlin.fir.resolve.BodyResolveComponents
 import org.jetbrains.kotlin.fir.resolve.calls.*
+import org.jetbrains.kotlin.fir.resolve.scope
+import org.jetbrains.kotlin.fir.typeContext
 import org.jetbrains.kotlin.fir.types.ConeClassLikeType
+import org.jetbrains.kotlin.resolve.calls.tasks.ExplicitReceiverKind
+import org.jetbrains.kotlin.types.AbstractTypeChecker
 
 class FirTowerResolver(
     private val components: BodyResolveComponents,
@@ -32,14 +36,35 @@ class FirTowerResolver(
 
     fun runResolverForDelegatingConstructor(
         info: CallInfo,
-        constructedType: ConeClassLikeType,
+        constructedType: ConeClassLikeType
     ): CandidateCollector {
-        val candidateFactoriesAndCollectors = buildCandidateFactoriesAndCollectors(info, collector)
+        val outerType = components.outerClassManager.outerType(constructedType)
+        val scope = constructedType.scope(components.session, components.scopeSession) ?: return collector
 
-        val towerResolverSession = FirTowerResolverSession(components, manager, candidateFactoriesAndCollectors, info)
-        towerResolverSession.runResolutionForDelegatingConstructor(info, constructedType)
+        val dispatchReceiver =
+            if (outerType != null)
+                components.implicitReceiverStack.receiversAsReversed().drop(1).firstOrNull {
+                    AbstractTypeChecker.isSubtypeOf(components.session.typeContext, it.type, outerType)
+                } ?: return collector // TODO: report diagnostic about not-found receiver
+            else
+                null
+
+        val candidateFactory = CandidateFactory(components, info)
+        val resultCollector = collector
+
+        scope.processDeclaredConstructors {
+            resultCollector.consumeCandidate(
+                TowerGroup.Member,
+                candidateFactory.createCandidate(
+                    it,
+                    ExplicitReceiverKind.NO_EXPLICIT_RECEIVER,
+                    dispatchReceiver,
+                    implicitExtensionReceiverValue = null,
+                    builtInExtensionFunctionReceiverValue = null
+                )
+            )
+        }
 
-        manager.runTasks()
         return collector
     }
 

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/tower/FirTowerResolverSession.kt

@@ -22,12 +22,10 @@ import org.jetbrains.kotlin.fir.scopes.ProcessorAction
 import org.jetbrains.kotlin.fir.symbols.impl.FirCallableSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirRegularClassSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirTypeAliasSymbol
-import org.jetbrains.kotlin.fir.typeContext
 import org.jetbrains.kotlin.fir.types.*
 import org.jetbrains.kotlin.fir.types.impl.FirImplicitBuiltinTypeRef
 import org.jetbrains.kotlin.resolve.calls.tasks.ExplicitReceiverKind
 import org.jetbrains.kotlin.resolve.descriptorUtil.HIDES_MEMBERS_NAME_LIST
-import org.jetbrains.kotlin.types.AbstractTypeChecker
 import org.jetbrains.kotlin.util.OperatorNameConventions
 
 class FirTowerResolverSession internal constructor(
@@ -66,13 +64,6 @@ class FirTowerResolverSession internal constructor(
         }
     }
 
-    fun runResolutionForDelegatingConstructor(
-        info: CallInfo,
-        constructedType: ConeClassLikeType
-    ) {
-        manager.enqueueResolverTask { runResolverForDelegatingConstructorCall(info, constructedType) }
-    }
-
     fun runResolution(info: CallInfo) {
         when (val receiver = info.explicitReceiver) {
             is FirResolvedQualifier -> manager.enqueueResolverTask { runResolverForQualifierReceiver(info, receiver) }
@@ -140,9 +131,6 @@ class FirTowerResolverSession internal constructor(
         extensionReceiver, extensionsOnly, includeInnerConstructors
     )
 
-    private fun FirScope.toConstructorScopeTowerLevel(dispatchReceiver: ImplicitReceiver?): ConstructorScopeTowerLevel =
-        ConstructorScopeTowerLevel(session, this, dispatchReceiver?.receiver)
-
     private fun ReceiverValue.toMemberScopeTowerLevel(
         extensionReceiver: ReceiverValue? = null,
         implicitExtensionInvokeMode: Boolean = false
@@ -213,27 +201,6 @@ class FirTowerResolverSession internal constructor(
         }
     }
 
-    private suspend fun runResolverForDelegatingConstructorCall(
-        info: CallInfo,
-        constructedType: ConeClassLikeType
-    ) {
-        val outerType = components.outerClassManager.outerType(constructedType)
-        val scope = constructedType.scope(session, components.scopeSession) ?: return
-
-        val dispatchReceiver =
-            if (outerType != null)
-                implicitReceivers.drop(1).firstOrNull {
-                    AbstractTypeChecker.isSubtypeOf(components.session.typeContext, it.receiver.type, outerType)
-                } ?: return // TODO: report diagnostic about not-found receiver
-            else
-                null
-
-        processLevel(
-            scope.toConstructorScopeTowerLevel(dispatchReceiver),
-            info, TowerGroup.Member
-        )
-    }
-
     private suspend fun runResolverForNoReceiver(
         info: CallInfo
     ) {

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/tower/TowerLevelHandler.kt

@@ -122,9 +122,6 @@ internal class TowerLevelHandler {
                     towerLevel.processFunctionsAndProperties(info.name, processor)
                 }
             }
-            CallKind.DelegatingConstructorCall -> {
-                towerLevel.processElementsByNameAndStoreResult(TowerScopeLevel.Token.ConstructorsForDelegationCall, info.name, processor)
-            }
             else -> {
                 throw AssertionError("Unsupported call kind in tower resolver: ${info.callKind}")
             }

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/tower/TowerLevels.kt

@@ -35,7 +35,6 @@ interface TowerScopeLevel {
     sealed class Token<out T : AbstractFirBasedSymbol<*>> {
         object Properties : Token<FirVariableSymbol<*>>()
         object Functions : Token<FirFunctionSymbol<*>>()
-        object ConstructorsForDelegationCall : Token<FirConstructorSymbol>()
         object Objects : Token<AbstractFirBasedSymbol<*>>()
     }
 
@@ -156,7 +155,6 @@ class MemberScopeTowerLevel(
                     consumer(it as T)
                 }
             }
-            TowerScopeLevel.Token.ConstructorsForDelegationCall -> error("ConstructorsForDelegationCall should be handled via ConstructorScopeTowerLevel")
         }
     }
 
@@ -263,38 +261,6 @@ class ScopeTowerLevel(
                     implicitExtensionReceiverValue = null
                 )
             }
-            TowerScopeLevel.Token.ConstructorsForDelegationCall -> {
-                throw AssertionError("Should not be here")
-            }
-        }
-        return if (empty) ProcessorAction.NONE else ProcessorAction.NEXT
-    }
-}
-
-class ConstructorScopeTowerLevel(
-    session: FirSession,
-    private val scope: FirScope,
-    private val dispatchReceiver: ImplicitReceiverValue<*>?,
-) : SessionBasedTowerLevel(session) {
-    override fun <T : AbstractFirBasedSymbol<*>> processElementsByName(
-        token: TowerScopeLevel.Token<T>,
-        name: Name,
-        processor: TowerScopeLevel.TowerScopeLevelProcessor<T>
-    ): ProcessorAction {
-        var empty = true
-        when (token) {
-            TowerScopeLevel.Token.ConstructorsForDelegationCall -> scope.processDeclaredConstructors { candidate ->
-                empty = false
-                @Suppress("UNCHECKED_CAST")
-                processor.consumeCandidate(
-                    candidate as T,
-                    dispatchReceiverValue = dispatchReceiver,
-                    implicitExtensionReceiverValue = null
-                )
-            }
-            else -> {
-                throw AssertionError("Should not be here: token = $token")
-            }
         }
         return if (empty) ProcessorAction.NONE else ProcessorAction.NEXT
     }