FIR: distinguish lazy/non-lazy nested scopes more clear

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/JavaSymbolProvider.kt

@@ -28,9 +28,7 @@ import org.jetbrains.kotlin.fir.java.scopes.JavaClassUseSiteMemberScope
 import org.jetbrains.kotlin.fir.java.scopes.JavaOverrideChecker
 import org.jetbrains.kotlin.fir.resolve.*
 import org.jetbrains.kotlin.fir.scopes.FirScope
-import org.jetbrains.kotlin.fir.scopes.impl.FirSuperTypeScope
-import org.jetbrains.kotlin.fir.scopes.impl.declaredMemberScope
-import org.jetbrains.kotlin.fir.scopes.impl.nestedClassifierScope
+import org.jetbrains.kotlin.fir.scopes.impl.*
 import org.jetbrains.kotlin.fir.symbols.CallableId
 import org.jetbrains.kotlin.fir.symbols.impl.*
 import org.jetbrains.kotlin.fir.toFirSourceElement
@@ -69,9 +67,8 @@ class JavaSymbolProvider(
         val symbol = this.getClassLikeSymbolByFqName(classId) ?: return null
         val regularClass = symbol.fir
         return if (regularClass is FirJavaClass) {
-            nestedClassifierScope(
+            lazyNestedClassifierScope(
                 classId,
-                session,
                 existingNames = regularClass.existingNestedClassifierNames,
                 symbolProvider = this
             )
@@ -110,12 +107,11 @@ class JavaSymbolProvider(
         visitedSymbols: MutableSet<FirClassLikeSymbol<*>>
     ): JavaClassUseSiteMemberScope {
         return scopeSession.getOrBuild(regularClass.symbol, JAVA_USE_SITE) {
-            val declaredScope = declaredMemberScope(
+            val declaredScope = if (regularClass is FirJavaClass) declaredMemberScopeWithLazyNestedScope(
                 regularClass,
-                useLazyNestedClassifierScope = regularClass is FirJavaClass,
-                existingNames = (regularClass as? FirJavaClass)?.existingNestedClassifierNames,
+                existingNames = regularClass.existingNestedClassifierNames,
                 symbolProvider = this
-            )
+            ) else declaredMemberScope(regularClass)
             val wrappedDeclaredScope = wrapScopeWithJvmMapped(regularClass, declaredScope, useSiteSession, scopeSession)
             val superTypeEnhancementScopes =
                 lookupSuperTypes(regularClass, lookupInterfaces = true, deep = false, useSiteSession = useSiteSession)

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

@@ -27,7 +27,7 @@ class FirClassDeclaredMemberScope(
     symbolProvider: FirSymbolProvider? = null
 ) : FirScope() {
     private val nestedClassifierScope = if (useLazyNestedClassifierScope) {
-        nestedClassifierScope(klass.symbol.classId, klass.session, existingNames, symbolProvider)
+        lazyNestedClassifierScope(klass.symbol.classId, existingNames!!, symbolProvider!!)
     } else {
         nestedClassifierScope(klass)
     }

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

@@ -5,9 +5,7 @@
 
 package org.jetbrains.kotlin.fir.scopes.impl
 
-import org.jetbrains.kotlin.fir.FirSession
 import org.jetbrains.kotlin.fir.resolve.FirSymbolProvider
-import org.jetbrains.kotlin.fir.resolve.firSymbolProvider
 import org.jetbrains.kotlin.fir.scopes.FirScope
 import org.jetbrains.kotlin.fir.scopes.ProcessorAction
 import org.jetbrains.kotlin.fir.symbols.impl.FirClassifierSymbol
@@ -19,18 +17,15 @@ import org.jetbrains.kotlin.name.Name
 // (or make possible to calculate nested classifiers on-the-fly)
 class FirLazyNestedClassifierScope(
     val classId: ClassId,
-    session: FirSession,
-    private val existingNames: List<Name>?,
-    symbolProvider: FirSymbolProvider?
+    private val existingNames: List<Name>,
+    private val symbolProvider: FirSymbolProvider
 ) : FirScope() {
 
-    private val symbolProvider = symbolProvider ?: session.firSymbolProvider
-
     override fun processClassifiersByName(
         name: Name,
         processor: (FirClassifierSymbol<*>) -> ProcessorAction
     ): ProcessorAction {
-        if (existingNames != null && name !in existingNames) {
+        if (name !in existingNames) {
             return ProcessorAction.NONE
         }
         val child = classId.createNestedClassId(name)

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

@@ -46,16 +46,22 @@ class FirMemberScopeProvider : FirSessionComponent {
     }
 }
 
-fun declaredMemberScope(
+fun declaredMemberScope(klass: FirClass<*>): FirScope {
+    return klass
+        .session
+        .memberScopeProvider
+        .declaredMemberScope(klass, useLazyNestedClassifierScope = false, existingNames = null, symbolProvider = null)
+}
+
+fun declaredMemberScopeWithLazyNestedScope(
     klass: FirClass<*>,
-    useLazyNestedClassifierScope: Boolean = false,
-    existingNames: List<Name>? = null,
-    symbolProvider: FirSymbolProvider? = null
+    existingNames: List<Name>,
+    symbolProvider: FirSymbolProvider
 ): FirScope {
     return klass
         .session
         .memberScopeProvider
-        .declaredMemberScope(klass, useLazyNestedClassifierScope, existingNames, symbolProvider)
+        .declaredMemberScope(klass, useLazyNestedClassifierScope = true, existingNames = existingNames, symbolProvider = symbolProvider)
 }
 
 fun nestedClassifierScope(klass: FirClass<*>): FirNestedClassifierScope {
@@ -65,13 +71,12 @@ fun nestedClassifierScope(klass: FirClass<*>): FirNestedClassifierScope {
         .nestedClassifierScope(klass)
 }
 
-fun nestedClassifierScope(
+fun lazyNestedClassifierScope(
     classId: ClassId,
-    session: FirSession,
-    existingNames: List<Name>? = null,
-    symbolProvider: FirSymbolProvider? = null
+    existingNames: List<Name>,
+    symbolProvider: FirSymbolProvider
 ): FirLazyNestedClassifierScope {
-    return FirLazyNestedClassifierScope(classId, session, existingNames, symbolProvider)
+    return FirLazyNestedClassifierScope(classId, existingNames, symbolProvider)
 }
 
 fun selfImportingScope(fqName: FqName, session: FirSession): FirSelfImportingScope {