diff --git a/analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/symbols/annotations/firAnnotationUtils.kt b/analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/symbols/annotations/firAnnotationUtils.kt
index d18258f0ff9..89882d0de92 100644
--- a/analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/symbols/annotations/firAnnotationUtils.kt
+++ b/analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/symbols/annotations/firAnnotationUtils.kt
@@ -13,7 +13,7 @@ import org.jetbrains.kotlin.fir.resolve.fullyExpandedType
 import org.jetbrains.kotlin.fir.types.classId
 import org.jetbrains.kotlin.fir.declarations.FirRegularClass
 import org.jetbrains.kotlin.fir.declarations.resolved
-import org.jetbrains.kotlin.fir.declarations.utils.primaryConstructor
+import org.jetbrains.kotlin.fir.declarations.primaryConstructorIfAny
 import org.jetbrains.kotlin.fir.expressions.*
 import org.jetbrains.kotlin.fir.resolve.toSymbol
 import org.jetbrains.kotlin.fir.types.ConeClassLikeType
@@ -42,7 +42,7 @@ internal fun mapAnnotationParameters(annotation: FirAnnotation, session: FirSess
     if (annotation !is FirAnnotationCall) return emptyMap()
     val annotationCone = annotation.annotationTypeRef.coneType as? ConeClassLikeType ?: return emptyMap()
 
-    val annotationPrimaryCtor = (annotationCone.lookupTag.toSymbol(session)?.fir as? FirRegularClass)?.primaryConstructor
+    val annotationPrimaryCtor = (annotationCone.lookupTag.toSymbol(session)?.fir as? FirRegularClass)?.primaryConstructorIfAny(session)?.fir
     val annotationCtorParameterNames = annotationPrimaryCtor?.valueParameters?.map { it.name }
 
     val resultMap = mutableMapOf<String, FirExpression>()
diff --git a/compiler/fir/checkers/checkers.jvm/src/org/jetbrains/kotlin/fir/analysis/jvm/checkers/declaration/FirJvmRecordChecker.kt b/compiler/fir/checkers/checkers.jvm/src/org/jetbrains/kotlin/fir/analysis/jvm/checkers/declaration/FirJvmRecordChecker.kt
index f03bdedb546..c4e0835e380 100644
--- a/compiler/fir/checkers/checkers.jvm/src/org/jetbrains/kotlin/fir/analysis/jvm/checkers/declaration/FirJvmRecordChecker.kt
+++ b/compiler/fir/checkers/checkers.jvm/src/org/jetbrains/kotlin/fir/analysis/jvm/checkers/declaration/FirJvmRecordChecker.kt
@@ -75,7 +75,7 @@ object FirJvmRecordChecker : FirRegularClassChecker() {
             return
         }
 
-        declaration.primaryConstructor?.valueParameters?.let { params ->
+        declaration.primaryConstructorIfAny(context.session)?.valueParameterSymbols?.let { params ->
             if (params.isEmpty()) {
                 reporter.reportOn(annotationSource, FirJvmErrors.JVM_RECORD_WITHOUT_PRIMARY_CONSTRUCTOR_PARAMETERS, context)
                 return
@@ -107,4 +107,4 @@ object FirJvmRecordChecker : FirRegularClassChecker() {
             }
         }
     }
-}
\ No newline at end of file
+}
diff --git a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirDataClassPrimaryConstructorChecker.kt b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirDataClassPrimaryConstructorChecker.kt
index abb7252e645..d757b2b6bce 100644
--- a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirDataClassPrimaryConstructorChecker.kt
+++ b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirDataClassPrimaryConstructorChecker.kt
@@ -8,13 +8,13 @@ package org.jetbrains.kotlin.fir.analysis.checkers.declaration
 import org.jetbrains.kotlin.descriptors.ClassKind
 import org.jetbrains.kotlin.fir.FirFakeSourceElementKind
 import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
-import org.jetbrains.kotlin.fir.analysis.checkers.hasValOrVar
 import org.jetbrains.kotlin.fir.analysis.diagnostics.DiagnosticReporter
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors
+import org.jetbrains.kotlin.fir.analysis.diagnostics.hasValOrVar
 import org.jetbrains.kotlin.fir.analysis.diagnostics.reportOn
 import org.jetbrains.kotlin.fir.declarations.FirRegularClass
 import org.jetbrains.kotlin.fir.declarations.utils.isData
-import org.jetbrains.kotlin.fir.declarations.utils.primaryConstructor
+import org.jetbrains.kotlin.fir.declarations.primaryConstructorIfAny
 
 object FirDataClassPrimaryConstructorChecker : FirRegularClassChecker() {
     override fun check(declaration: FirRegularClass, context: CheckerContext, reporter: DiagnosticReporter) {
@@ -22,14 +22,14 @@ object FirDataClassPrimaryConstructorChecker : FirRegularClassChecker() {
             return
         }
 
-        val primaryConstructor = declaration.primaryConstructor
+        val primaryConstructor = declaration.primaryConstructorIfAny(context.session)
 
         if (primaryConstructor == null || primaryConstructor.source.let { it == null || it.kind is FirFakeSourceElementKind }) {
             reporter.reportOn(declaration.source, FirErrors.PRIMARY_CONSTRUCTOR_REQUIRED_FOR_DATA_CLASS, context)
             return
         }
 
-        val valueParameters = primaryConstructor.valueParameters
+        val valueParameters = primaryConstructor.valueParameterSymbols
         if (valueParameters.isEmpty()) {
             reporter.reportOn(primaryConstructor.source, FirErrors.DATA_CLASS_WITHOUT_PARAMETERS, context)
         }
@@ -37,7 +37,7 @@ object FirDataClassPrimaryConstructorChecker : FirRegularClassChecker() {
             if (parameter.isVararg) {
                 reporter.reportOn(parameter.source, FirErrors.DATA_CLASS_VARARG_PARAMETER, context)
             }
-            if (!parameter.hasValOrVar) {
+            if (parameter.source?.hasValOrVar() != true) {
                 reporter.reportOn(parameter.source, FirErrors.DATA_CLASS_NOT_PROPERTY_PARAMETER, context)
             }
         }
diff --git a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirMemberPropertiesChecker.kt b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirMemberPropertiesChecker.kt
index f94fcc30e96..5b21d928274 100644
--- a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirMemberPropertiesChecker.kt
+++ b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirMemberPropertiesChecker.kt
@@ -10,6 +10,7 @@ import org.jetbrains.kotlin.contracts.description.isDefinitelyVisited
 import org.jetbrains.kotlin.descriptors.Visibilities
 import org.jetbrains.kotlin.fir.FirElement
 import org.jetbrains.kotlin.fir.FirFakeSourceElementKind
+import org.jetbrains.kotlin.fir.FirSession
 import org.jetbrains.kotlin.fir.analysis.cfa.util.PropertyInitializationInfo
 import org.jetbrains.kotlin.fir.analysis.cfa.util.PropertyInitializationInfoCollector
 import org.jetbrains.kotlin.fir.analysis.checkers.contains
@@ -26,6 +27,7 @@ import org.jetbrains.kotlin.fir.resolve.dfa.cfg.BlockExitNode
 import org.jetbrains.kotlin.fir.resolve.dfa.cfg.ControlFlowGraph
 import org.jetbrains.kotlin.fir.resolve.dfa.cfg.NormalPath
 import org.jetbrains.kotlin.fir.resolve.dfa.controlFlowGraph
+import org.jetbrains.kotlin.fir.symbols.impl.FirConstructorSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirPropertySymbol
 import org.jetbrains.kotlin.lexer.KtTokens
 
@@ -40,7 +42,13 @@ object FirMemberPropertiesChecker : FirClassChecker() {
 
         // If all member properties have its own initializer, we don't need to collect property initialization info at all.
         if (memberPropertySymbols.any { !it.hasInitializer }) {
-            collectPropertyInitialization(declaration, memberPropertySymbols, initializedInConstructor, initializedInInitOrOtherProperty)
+            collectPropertyInitialization(
+                declaration,
+                context.session,
+                memberPropertySymbols,
+                initializedInConstructor,
+                initializedInInitOrOtherProperty
+            )
         }
 
         val deadEnds = declaration.collectDeadEndDeclarations()
@@ -60,6 +68,7 @@ object FirMemberPropertiesChecker : FirClassChecker() {
 
     private fun collectPropertyInitialization(
         klass: FirClass,
+        session: FirSession,
         memberPropertySymbols: Set<FirPropertySymbol>,
         initializedInConstructor: MutableMap<FirPropertySymbol, EventOccurrencesRange>,
         initializedInInitOrOtherProperty: MutableMap<FirPropertySymbol, EventOccurrencesRange>
@@ -86,13 +95,13 @@ object FirMemberPropertiesChecker : FirClassChecker() {
 
         // To handle the delegated constructor call, we need a cache from constructor to (analyzed) property init info.
         val constructorToData =
-            mutableMapOf<FirConstructor, PropertyInitializationInfo>().withDefault { PropertyInitializationInfo.EMPTY }
+            mutableMapOf<FirConstructorSymbol, PropertyInitializationInfo>().withDefault { PropertyInitializationInfo.EMPTY }
 
         fun collectInfoFromGraph(
             graph: ControlFlowGraph,
             map: MutableMap<FirPropertySymbol, EventOccurrencesRange>,
             acc: (EventOccurrencesRange, EventOccurrencesRange) -> EventOccurrencesRange,
-            delegatedConstructor: FirConstructor? = null,
+            delegatedConstructor: FirConstructorSymbol? = null,
         ) {
             val delegatedInfo = delegatedConstructor?.let { constructorToData.getValue(it) } ?: PropertyInitializationInfo.EMPTY
 
@@ -104,7 +113,7 @@ object FirMemberPropertiesChecker : FirClassChecker() {
             val info = delegatedInfo.plus(infoAtExitNode)
 
             if (graph.declaration is FirConstructor) {
-                constructorToData.putIfAbsent(graph.declaration as FirConstructor, info)
+                constructorToData.putIfAbsent((graph.declaration as FirConstructor).symbol, info)
             }
 
             for (propertySymbol in memberPropertySymbols) {
@@ -122,13 +131,15 @@ object FirMemberPropertiesChecker : FirClassChecker() {
             }
         }
 
-        val constructorGraphs = klass.constructorsSortedByDelegation.mapNotNull { it.controlFlowGraphReference?.controlFlowGraph }
+        val constructorGraphs = klass.constructorsSortedByDelegation(session).mapNotNull {
+            it.resolvedControlFlowGraphReference?.controlFlowGraph
+        }
         for (graph in constructorGraphs) {
             collectInfoFromGraph(
                 graph,
                 initializedInConstructor,
                 EventOccurrencesRange::or,
-                (graph.declaration as? FirConstructor)?.delegatedThisConstructor
+                (graph.declaration as? FirConstructor)?.symbol?.delegatedThisConstructor
             )
         }
 
diff --git a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirPrimaryConstructorSuperTypeChecker.kt b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirPrimaryConstructorSuperTypeChecker.kt
index 99e73d17d1b..fd0d95edc22 100644
--- a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirPrimaryConstructorSuperTypeChecker.kt
+++ b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirPrimaryConstructorSuperTypeChecker.kt
@@ -13,10 +13,10 @@ import org.jetbrains.kotlin.fir.analysis.checkers.toRegularClassSymbol
 import org.jetbrains.kotlin.fir.analysis.diagnostics.DiagnosticReporter
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors
 import org.jetbrains.kotlin.fir.analysis.diagnostics.reportOn
-import org.jetbrains.kotlin.fir.declarations.FirConstructor
 import org.jetbrains.kotlin.fir.declarations.FirRegularClass
 import org.jetbrains.kotlin.fir.declarations.utils.isInterface
-import org.jetbrains.kotlin.fir.declarations.utils.primaryConstructor
+import org.jetbrains.kotlin.fir.declarations.primaryConstructorIfAny
+import org.jetbrains.kotlin.fir.symbols.impl.FirConstructorSymbol
 import org.jetbrains.kotlin.name.StandardClassIds
 import org.jetbrains.kotlin.fir.types.*
 import org.jetbrains.kotlin.fir.types.impl.FirImplicitAnyTypeRef
@@ -36,12 +36,12 @@ object FirPrimaryConstructorSuperTypeChecker : FirRegularClassChecker() {
             return
         }
 
-        val primaryConstructor = declaration.primaryConstructor
+        val primaryConstructorSymbol = declaration.primaryConstructorIfAny(context.session)
 
-        if (primaryConstructor == null) {
+        if (primaryConstructorSymbol == null) {
             checkSupertypeInitializedWithoutPrimaryConstructor(declaration, reporter, context)
         } else {
-            checkSuperTypeNotInitialized(primaryConstructor, declaration, context, reporter)
+            checkSuperTypeNotInitialized(primaryConstructorSymbol, declaration, context, reporter)
         }
     }
 
@@ -55,13 +55,13 @@ object FirPrimaryConstructorSuperTypeChecker : FirRegularClassChecker() {
      *  ```
      */
     private fun checkSuperTypeNotInitialized(
-        primaryConstructor: FirConstructor,
+        primaryConstructorSymbol: FirConstructorSymbol,
         regularClass: FirRegularClass,
         context: CheckerContext,
         reporter: DiagnosticReporter
     ) {
         val containingClass = context.containingDeclarations.lastIsInstanceOrNull<FirRegularClass>()
-        val delegatedConstructorCall = primaryConstructor.delegatedConstructor ?: return
+        val delegatedConstructorCall = primaryConstructorSymbol.resolvedDelegatedConstructorCall ?: return
         // No need to check implicit call to the constructor of `kotlin.Any`.
         val constructedTypeRef = delegatedConstructorCall.constructedTypeRef
         if (constructedTypeRef is FirImplicitAnyTypeRef) return
diff --git a/compiler/fir/fir-deserialization/src/org/jetbrains/kotlin/fir/deserialization/AbstractAnnotationDeserializer.kt b/compiler/fir/fir-deserialization/src/org/jetbrains/kotlin/fir/deserialization/AbstractAnnotationDeserializer.kt
index ed80fff8a1f..e66746b9ecd 100644
--- a/compiler/fir/fir-deserialization/src/org/jetbrains/kotlin/fir/deserialization/AbstractAnnotationDeserializer.kt
+++ b/compiler/fir/fir-deserialization/src/org/jetbrains/kotlin/fir/deserialization/AbstractAnnotationDeserializer.kt
@@ -9,7 +9,7 @@ import org.jetbrains.kotlin.descriptors.annotations.AnnotationUseSiteTarget
 import org.jetbrains.kotlin.fir.FirSession
 import org.jetbrains.kotlin.fir.declarations.FirRegularClass
 import org.jetbrains.kotlin.fir.declarations.FirValueParameter
-import org.jetbrains.kotlin.fir.declarations.utils.collectEnumEntries
+import org.jetbrains.kotlin.fir.declarations.collectEnumEntries
 import org.jetbrains.kotlin.fir.diagnostics.ConeSimpleDiagnostic
 import org.jetbrains.kotlin.fir.diagnostics.DiagnosticKind
 import org.jetbrains.kotlin.fir.expressions.*
diff --git a/compiler/fir/fir-serialization/src/org/jetbrains/kotlin/fir/serialization/FirElementSerializer.kt b/compiler/fir/fir-serialization/src/org/jetbrains/kotlin/fir/serialization/FirElementSerializer.kt
index 0f009be68c2..fca24e6ce9c 100644
--- a/compiler/fir/fir-serialization/src/org/jetbrains/kotlin/fir/serialization/FirElementSerializer.kt
+++ b/compiler/fir/fir-serialization/src/org/jetbrains/kotlin/fir/serialization/FirElementSerializer.kt
@@ -186,7 +186,7 @@ class FirElementSerializer private constructor(
             builder.typeTable = typeTableProto
         }
 
-        val representation = (klass as? FirRegularClass)?.getInlineClassUnderlyingParameter()
+        val representation = (klass as? FirRegularClass)?.getInlineClassUnderlyingParameter(session)
         if (representation != null) {
             builder.inlineClassUnderlyingPropertyName = getSimpleNameIndex(representation.name)
 
diff --git a/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/ConversionUtils.kt b/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/ConversionUtils.kt
index 4a1a421b76e..906128f33a8 100644
--- a/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/ConversionUtils.kt
+++ b/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/ConversionUtils.kt
@@ -561,7 +561,7 @@ fun Fir2IrComponents.createTemporaryVariableForSafeCallConstruction(
 // TODO: implement inlineClassRepresentation in FirRegularClass instead.
 fun Fir2IrComponents.computeInlineClassRepresentation(klass: FirRegularClass): InlineClassRepresentation<IrSimpleType>? {
     if (!klass.isInline) return null
-    val parameter = klass.getInlineClassUnderlyingParameter() ?: error("Inline class has no underlying parameter: ${klass.render()}")
+    val parameter = klass.getInlineClassUnderlyingParameter(session) ?: error("Inline class has no underlying parameter: ${klass.render()}")
     val underlyingType = parameter.returnTypeRef.toIrType(typeConverter)
     return InlineClassRepresentation(
         parameter.name,
diff --git a/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrConverter.kt b/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrConverter.kt
index e3db6a03674..a4845526f17 100644
--- a/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrConverter.kt
+++ b/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrConverter.kt
@@ -7,7 +7,6 @@ package org.jetbrains.kotlin.fir.backend
 
 import org.jetbrains.kotlin.backend.common.extensions.IrGenerationExtension
 import org.jetbrains.kotlin.backend.common.extensions.IrPluginContext
-import org.jetbrains.kotlin.backend.common.extensions.IrPluginContextImpl
 import org.jetbrains.kotlin.backend.common.ir.BuiltinSymbolsBase
 import org.jetbrains.kotlin.config.AnalysisFlags
 import org.jetbrains.kotlin.config.LanguageVersionSettings
@@ -19,7 +18,7 @@ import org.jetbrains.kotlin.fir.backend.generators.DataClassMembersGenerator
 import org.jetbrains.kotlin.fir.declarations.*
 import org.jetbrains.kotlin.fir.declarations.utils.isLocal
 import org.jetbrains.kotlin.fir.declarations.utils.isSynthetic
-import org.jetbrains.kotlin.fir.declarations.utils.primaryConstructor
+import org.jetbrains.kotlin.fir.declarations.primaryConstructorIfAny
 import org.jetbrains.kotlin.fir.descriptors.FirModuleDescriptor
 import org.jetbrains.kotlin.fir.extensions.declarationGenerators
 import org.jetbrains.kotlin.fir.extensions.extensionService
@@ -129,9 +128,9 @@ class Fir2IrConverter(
         anonymousObject: FirAnonymousObject,
         irClass: IrClass = classifierStorage.getCachedIrClass(anonymousObject)!!
     ): IrClass {
-        anonymousObject.primaryConstructor?.let {
+        anonymousObject.primaryConstructorIfAny(session)?.let {
             irClass.declarations += declarationStorage.createIrConstructor(
-                it, irClass, isLocal = true
+                it.fir, irClass, isLocal = true
             )
         }
         val processedCallableNames = mutableSetOf<Name>()
diff --git a/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrVisitor.kt b/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrVisitor.kt
index 8414fcc571b..c3f7eea6f65 100644
--- a/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrVisitor.kt
+++ b/compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrVisitor.kt
@@ -127,7 +127,7 @@ class Fir2IrVisitor(
         } else if (initializer is FirAnonymousObjectExpression) {
             // Otherwise, this is a default-ish enum entry, which doesn't need its own synthetic class.
             // During raw FIR building, we put the delegated constructor call inside an anonymous object.
-            val delegatedConstructor = initializer.anonymousObject.primaryConstructor?.delegatedConstructor
+            val delegatedConstructor = initializer.anonymousObject.primaryConstructorIfAny(session)?.fir?.delegatedConstructor
             if (delegatedConstructor != null) {
                 with(memberGenerator) {
                     irEnumEntry.initializerExpression = irFactory.createExpressionBody(
diff --git a/compiler/fir/java/src/org/jetbrains/kotlin/fir/java/enhancement/javaTypeUtils.kt b/compiler/fir/java/src/org/jetbrains/kotlin/fir/java/enhancement/javaTypeUtils.kt
index 0aa8db23ac8..8ed81bf1174 100644
--- a/compiler/fir/java/src/org/jetbrains/kotlin/fir/java/enhancement/javaTypeUtils.kt
+++ b/compiler/fir/java/src/org/jetbrains/kotlin/fir/java/enhancement/javaTypeUtils.kt
@@ -10,7 +10,7 @@ import org.jetbrains.kotlin.descriptors.ClassKind
 import org.jetbrains.kotlin.descriptors.Modality
 import org.jetbrains.kotlin.fir.FirSession
 import org.jetbrains.kotlin.fir.declarations.FirRegularClass
-import org.jetbrains.kotlin.fir.declarations.utils.collectEnumEntries
+import org.jetbrains.kotlin.fir.declarations.collectEnumEntries
 import org.jetbrains.kotlin.fir.declarations.utils.isStatic
 import org.jetbrains.kotlin.fir.declarations.utils.modality
 import org.jetbrains.kotlin.fir.expressions.FirExpression
diff --git a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/declarations/InlineClassesUtils.kt b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/declarations/InlineClassesUtils.kt
index c727fa80d7e..bee9f65977e 100644
--- a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/declarations/InlineClassesUtils.kt
+++ b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/declarations/InlineClassesUtils.kt
@@ -7,7 +7,6 @@ package org.jetbrains.kotlin.fir.declarations
 
 import org.jetbrains.kotlin.fir.FirSession
 import org.jetbrains.kotlin.fir.declarations.utils.isInline
-import org.jetbrains.kotlin.fir.declarations.utils.primaryConstructor
 import org.jetbrains.kotlin.fir.resolve.fullyExpandedType
 import org.jetbrains.kotlin.fir.resolve.substitution.createTypeSubstitutorByTypeConstructor
 import org.jetbrains.kotlin.fir.resolve.toSymbol
@@ -31,9 +30,9 @@ internal fun ConeKotlinType.unsubstitutedUnderlyingTypeForInlineClass(session: F
         ?.toSymbol(session) as? FirRegularClassSymbol
         ?: return null
     symbol.ensureResolved(FirResolvePhase.STATUS)
-    return symbol.fir.getInlineClassUnderlyingParameter()?.returnTypeRef?.coneType
+    return symbol.fir.getInlineClassUnderlyingParameter(session)?.returnTypeRef?.coneType
 }
 
 // TODO: implement inlineClassRepresentation in FirRegularClass instead.
-fun FirRegularClass.getInlineClassUnderlyingParameter(): FirValueParameter? =
-    if (isInline) primaryConstructor?.valueParameters?.singleOrNull() else null
+fun FirRegularClass.getInlineClassUnderlyingParameter(session: FirSession): FirValueParameter? =
+    if (isInline) primaryConstructorIfAny(session)?.fir?.valueParameters?.singleOrNull() else null
diff --git a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/declarations/declarationUtils.kt b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/declarations/declarationUtils.kt
new file mode 100644
index 00000000000..58400b8c58f
--- /dev/null
+++ b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/declarations/declarationUtils.kt
@@ -0,0 +1,48 @@
+/*
+ * Copyright 2010-2021 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.fir.declarations
+
+import org.jetbrains.kotlin.descriptors.ClassKind
+import org.jetbrains.kotlin.fir.FirSession
+import org.jetbrains.kotlin.fir.scopes.impl.declaredMemberScope
+import org.jetbrains.kotlin.fir.symbols.impl.FirConstructorSymbol
+import org.jetbrains.kotlin.utils.addToStdlib.runIf
+
+fun FirClass.constructors(session: FirSession): List<FirConstructorSymbol> {
+    val result = mutableListOf<FirConstructorSymbol>()
+    session.declaredMemberScope(this).processDeclaredConstructors { result += it }
+    return result
+}
+
+fun FirClass.constructorsSortedByDelegation(session: FirSession): List<FirConstructorSymbol> {
+    return constructors(session).sortedWith(ConstructorDelegationComparator)
+}
+
+fun FirClass.primaryConstructorIfAny(session: FirSession): FirConstructorSymbol? {
+    return constructors(session).find(FirConstructorSymbol::isPrimary)
+}
+
+fun FirRegularClass.collectEnumEntries(): Collection<FirEnumEntry> {
+    assert(classKind == ClassKind.ENUM_CLASS)
+    return declarations.filterIsInstance<FirEnumEntry>()
+}
+
+val FirConstructorSymbol.delegatedThisConstructor: FirConstructorSymbol?
+    get() = runIf(delegatedConstructorCallIsThis) { this.resolvedDelegatedConstructor }
+
+
+private object ConstructorDelegationComparator : Comparator<FirConstructorSymbol> {
+    override fun compare(p0: FirConstructorSymbol?, p1: FirConstructorSymbol?): Int {
+        if (p0 == null && p1 == null) return 0
+        if (p0 == null) return -1
+        if (p1 == null) return 1
+        if (p0.delegatedThisConstructor == p1) return 1
+        if (p1.delegatedThisConstructor == p0) return -1
+        // If neither is a delegation to each other, the order doesn't matter.
+        // Here we return 0 to preserve the original order.
+        return 0
+    }
+}
diff --git a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/FirWhenExhaustivenessTransformer.kt b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/FirWhenExhaustivenessTransformer.kt
index c329bcbe846..6321b6fd531 100644
--- a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/FirWhenExhaustivenessTransformer.kt
+++ b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/FirWhenExhaustivenessTransformer.kt
@@ -13,7 +13,7 @@ import org.jetbrains.kotlin.fir.FirSession
 import org.jetbrains.kotlin.fir.declarations.FirEnumEntry
 import org.jetbrains.kotlin.fir.declarations.FirRegularClass
 import org.jetbrains.kotlin.fir.declarations.getSealedClassInheritors
-import org.jetbrains.kotlin.fir.declarations.utils.collectEnumEntries
+import org.jetbrains.kotlin.fir.declarations.collectEnumEntries
 import org.jetbrains.kotlin.fir.declarations.utils.modality
 import org.jetbrains.kotlin.fir.expressions.*
 import org.jetbrains.kotlin.fir.expressions.LogicOperationKind.OR
diff --git a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/body/resolve/BodyResolveContext.kt b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/body/resolve/BodyResolveContext.kt
index 945361eaaa0..74549cc1cf9 100644
--- a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/body/resolve/BodyResolveContext.kt
+++ b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/body/resolve/BodyResolveContext.kt
@@ -12,7 +12,7 @@ import org.jetbrains.kotlin.fir.declarations.*
 import org.jetbrains.kotlin.fir.declarations.impl.FirDefaultPropertyAccessor
 import org.jetbrains.kotlin.fir.declarations.utils.isCompanion
 import org.jetbrains.kotlin.fir.declarations.utils.isInner
-import org.jetbrains.kotlin.fir.declarations.utils.primaryConstructor
+import org.jetbrains.kotlin.fir.declarations.primaryConstructorIfAny
 import org.jetbrains.kotlin.fir.expressions.FirCallableReferenceAccess
 import org.jetbrains.kotlin.fir.expressions.FirExpression
 import org.jetbrains.kotlin.fir.expressions.FirWhenExpression
@@ -406,7 +406,7 @@ class BodyResolveContext(
     ): T {
         val labelName = (owner as? FirRegularClass)?.name
             ?: if (owner.classKind == ClassKind.ENUM_ENTRY) {
-                owner.primaryConstructor?.symbol?.callableId?.className?.shortName()
+                owner.primaryConstructorIfAny(holder.session)?.callableId?.className?.shortName()
             } else null
         val type = owner.defaultType()
         val towerElementsForClass = holder.collectTowerDataElementsForClass(owner, type)
diff --git a/compiler/fir/tree/src/org/jetbrains/kotlin/fir/declarations/utils/FirDeclarationUtil.kt b/compiler/fir/tree/src/org/jetbrains/kotlin/fir/declarations/utils/FirDeclarationUtil.kt
index 8dd686a4eae..38c91b999af 100644
--- a/compiler/fir/tree/src/org/jetbrains/kotlin/fir/declarations/utils/FirDeclarationUtil.kt
+++ b/compiler/fir/tree/src/org/jetbrains/kotlin/fir/declarations/utils/FirDeclarationUtil.kt
@@ -5,14 +5,10 @@
 
 package org.jetbrains.kotlin.fir.declarations.utils
 
-import org.jetbrains.kotlin.descriptors.ClassKind
 import org.jetbrains.kotlin.fir.declarations.*
 import org.jetbrains.kotlin.fir.expressions.FirQualifiedAccess
 import org.jetbrains.kotlin.fir.references.FirResolvedNamedReference
-import org.jetbrains.kotlin.fir.symbols.impl.FirAnonymousObjectSymbol
-import org.jetbrains.kotlin.fir.symbols.impl.FirClassSymbol
-import org.jetbrains.kotlin.fir.symbols.impl.FirPropertySymbol
-import org.jetbrains.kotlin.fir.symbols.impl.FirRegularClassSymbol
+import org.jetbrains.kotlin.fir.symbols.impl.*
 import org.jetbrains.kotlin.fir.types.ConeClassLikeType
 import org.jetbrains.kotlin.fir.types.coneTypeSafe
 import org.jetbrains.kotlin.name.ClassId
@@ -38,24 +34,6 @@ val FirClass.superConeTypes: List<ConeClassLikeType> get() = superTypeRefs.mapNo
 val FirClass.anonymousInitializers: List<FirAnonymousInitializer>
     get() = declarations.filterIsInstance<FirAnonymousInitializer>()
 
-val FirClass.constructors: List<FirConstructor>
-    get() = declarations.filterIsInstance<FirConstructor>()
-
-val FirConstructor.delegatedThisConstructor: FirConstructor?
-    get() = delegatedConstructor?.takeIf { it.isThis }
-        ?.let { (it.calleeReference as? FirResolvedNamedReference)?.resolvedSymbol?.fir as? FirConstructor }
-
-val FirClass.constructorsSortedByDelegation: List<FirConstructor>
-    get() = constructors.sortedWith(ConstructorDelegationComparator)
-
-val FirClass.primaryConstructor: FirConstructor?
-    get() = constructors.find(FirConstructor::isPrimary)
-
-fun FirRegularClass.collectEnumEntries(): Collection<FirEnumEntry> {
-    assert(classKind == ClassKind.ENUM_CLASS)
-    return declarations.filterIsInstance<FirEnumEntry>()
-}
-
 val FirQualifiedAccess.referredPropertySymbol: FirPropertySymbol?
     get() {
         val reference = calleeReference as? FirResolvedNamedReference ?: return null
@@ -69,16 +47,4 @@ inline val FirDeclaration.isFromLibrary: Boolean
 inline val FirDeclaration.isSynthetic: Boolean
     get() = origin == FirDeclarationOrigin.Synthetic
 
-private object ConstructorDelegationComparator : Comparator<FirConstructor> {
-    override fun compare(p0: FirConstructor?, p1: FirConstructor?): Int {
-        if (p0 == null && p1 == null) return 0
-        if (p0 == null) return -1
-        if (p1 == null) return 1
-        if (p0.delegatedThisConstructor == p1) return 1
-        if (p1.delegatedThisConstructor == p0) return -1
-        // If neither is a delegation to each other, the order doesn't matter.
-        // Here we return 0 to preserve the original order.
-        return 0
-    }
-}
 
diff --git a/compiler/fir/tree/src/org/jetbrains/kotlin/fir/symbols/impl/FirFunctionSymbol.kt b/compiler/fir/tree/src/org/jetbrains/kotlin/fir/symbols/impl/FirFunctionSymbol.kt
index 3e6e6d0a498..a3f861a094d 100644
--- a/compiler/fir/tree/src/org/jetbrains/kotlin/fir/symbols/impl/FirFunctionSymbol.kt
+++ b/compiler/fir/tree/src/org/jetbrains/kotlin/fir/symbols/impl/FirFunctionSymbol.kt
@@ -8,6 +8,9 @@ package org.jetbrains.kotlin.fir.symbols.impl
 import org.jetbrains.kotlin.fir.FirLabel
 import org.jetbrains.kotlin.fir.contracts.FirResolvedContractDescription
 import org.jetbrains.kotlin.fir.declarations.*
+import org.jetbrains.kotlin.fir.expressions.FirDelegatedConstructorCall
+import org.jetbrains.kotlin.fir.references.FirControlFlowGraphReference
+import org.jetbrains.kotlin.fir.references.FirResolvedNamedReference
 import org.jetbrains.kotlin.fir.symbols.AccessorSymbol
 import org.jetbrains.kotlin.fir.symbols.FirBasedSymbol
 import org.jetbrains.kotlin.fir.symbols.ensureResolved
@@ -30,6 +33,12 @@ sealed class FirFunctionSymbol<D : FirFunction>(
                 else -> null
             } as? FirResolvedContractDescription
         }
+
+    val resolvedControlFlowGraphReference: FirControlFlowGraphReference?
+        get() {
+            ensureResolved(FirResolvePhase.BODY_RESOLVE)
+            return fir.controlFlowGraphReference
+        }
 }
 
 // ------------------------ named ------------------------
@@ -52,6 +61,25 @@ class FirConstructorSymbol(
 ) : FirFunctionSymbol<FirConstructor>(callableId) {
     val isPrimary: Boolean
         get() = fir.isPrimary
+
+    val resolvedDelegatedConstructor: FirConstructorSymbol?
+        get() {
+            val delegatedConstructorCall = resolvedDelegatedConstructorCall ?: return null
+            return (delegatedConstructorCall.calleeReference as? FirResolvedNamedReference)?.resolvedSymbol as? FirConstructorSymbol
+        }
+
+    val resolvedDelegatedConstructorCall: FirDelegatedConstructorCall?
+        get() {
+            if (fir.delegatedConstructor == null) return null
+            ensureResolved(FirResolvePhase.BODY_RESOLVE)
+            return fir.delegatedConstructor
+        }
+
+    val delegatedConstructorCallIsThis: Boolean
+        get() = fir.delegatedConstructor?.isThis ?: false
+
+    val delegatedConstructorCallIsSuper: Boolean
+        get() = fir.delegatedConstructor?.isSuper ?: false
 }
 
 open class FirAccessorSymbol(