Cache declared member scope

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/FirModuleBasedSession.kt

@@ -8,6 +8,7 @@ package org.jetbrains.kotlin.fir
 import org.jetbrains.kotlin.analyzer.ModuleInfo
 import org.jetbrains.kotlin.fir.resolve.*
 import org.jetbrains.kotlin.fir.resolve.impl.*
+import org.jetbrains.kotlin.fir.scopes.impl.FirClassDeclaredMemberScopeProvider
 
 abstract class FirModuleBasedSession(override val moduleInfo: ModuleInfo) : FirSessionBase() {
     init {
@@ -15,6 +16,7 @@ abstract class FirModuleBasedSession(override val moduleInfo: ModuleInfo) : FirS
         registerComponent(FirProvider::class, firProvider)
         registerComponent(FirQualifierResolver::class, FirQualifierResolverImpl(this))
         registerComponent(FirTypeResolver::class, FirTypeResolverImpl(this))
+        registerComponent(FirClassDeclaredMemberScopeProvider::class, FirClassDeclaredMemberScopeProvider())
     }
 }
 

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/SupertypeUtils.kt

@@ -66,7 +66,7 @@ fun FirTypeAlias.buildUseSiteScope(useSiteSession: FirSession, builder: ScopeSes
 fun FirRegularClass.buildDefaultUseSiteScope(useSiteSession: FirSession, builder: ScopeSession): FirScope {
     return builder.getOrBuild(symbol, USE_SITE) {
 
-        val declaredScope = builder.getOrBuild(this.symbol, DECLARED) { FirClassDeclaredMemberScope(this) }
+        val declaredScope = builder.getOrBuild(this.symbol, DECLARED) { declaredMemberScope(this) }
         val scopes = lookupSuperTypes(this, lookupInterfaces = true, deep = false, useSiteSession = useSiteSession)
             .mapNotNull { useSiteSuperType ->
                 if (useSiteSuperType is ConeClassErrorType) return@mapNotNull null

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/scopes/impl/FirClassDeclaredMemberScope.kt

@@ -13,13 +13,31 @@ import org.jetbrains.kotlin.fir.scopes.FirScope
 import org.jetbrains.kotlin.fir.scopes.ProcessorAction
 import org.jetbrains.kotlin.fir.scopes.ProcessorAction.NEXT
 import org.jetbrains.kotlin.fir.scopes.ProcessorAction.STOP
+import org.jetbrains.kotlin.fir.service
 import org.jetbrains.kotlin.fir.symbols.*
 import org.jetbrains.kotlin.fir.symbols.impl.FirCallableSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirClassSymbol
 import org.jetbrains.kotlin.name.Name
 
+class FirClassDeclaredMemberScopeProvider {
+
+    val cache = mutableMapOf<FirRegularClass, FirClassDeclaredMemberScope>()
+    fun declaredMemberScope(klass: FirRegularClass): FirClassDeclaredMemberScope {
+        return cache.getOrPut(klass) {
+            FirClassDeclaredMemberScope(klass)
+        }
+    }
+}
+
+fun declaredMemberScope(klass: FirRegularClass): FirClassDeclaredMemberScope {
+    return klass
+        .session
+        .service<FirClassDeclaredMemberScopeProvider>()
+        .declaredMemberScope(klass)
+}
+
 class FirClassDeclaredMemberScope(klass: FirRegularClass) : FirScope {
-    private val callablesIndex: Map<Name, List<FirCallableSymbol>> by lazy {
+    private val callablesIndex: Map<Name, List<FirCallableSymbol>> = run {
         val result = mutableMapOf<Name, MutableList<FirCallableSymbol>>()
         for (declaration in klass.declarations) {
             when (declaration) {
@@ -38,7 +56,7 @@ class FirClassDeclaredMemberScope(klass: FirRegularClass) : FirScope {
         }
         result
     }
-    private val classIndex: Map<Name, FirClassSymbol> by lazy {
+    private val classIndex: Map<Name, FirClassSymbol> = run {
         val result = mutableMapOf<Name, FirClassSymbol>()
         for (declaration in klass.declarations) {
             if (declaration is FirRegularClass) {