[FIR] Replace inheritance with delegation for FirProvider and FirSymbolProvider

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrDeclarationStorage.kt

@@ -748,7 +748,7 @@ class Fir2IrDeclarationStorage(
     }
 
     private fun getFirClassByFqName(classId: ClassId): FirClass<*>? {
-        val declaration = firProvider.getClassLikeSymbolByFqName(classId) ?: firSymbolProvider.getClassLikeSymbolByFqName(classId)
+        val declaration = firSymbolProvider.getClassLikeSymbolByFqName(classId)
         return declaration?.fir as? FirClass<*>
     }
 

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

@@ -43,12 +43,12 @@ class FirJavaElementFinder(
     private val firProvider = session.firProvider
 
     override fun findPackage(qualifiedName: String): PsiPackage? {
-        if (firProvider.getClassNamesInPackage(FqName(qualifiedName)).isEmpty()) return null
+        if (firProvider.symbolProvider.getClassNamesInPackage(FqName(qualifiedName)).isEmpty()) return null
         return PsiPackageImpl(psiManager, qualifiedName)
     }
 
     override fun getClasses(psiPackage: PsiPackage, scope: GlobalSearchScope): Array<PsiClass> {
-        return firProvider
+        return firProvider.symbolProvider
             .getClassNamesInPackage(FqName(psiPackage.qualifiedName))
             .mapNotNull { findClass(psiPackage.qualifiedName + "." + it.identifier, scope) }
             .toTypedArray()

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

@@ -49,7 +49,7 @@ class FirJavaModuleBasedSession private constructor(
                     FirSymbolProvider::class,
                     FirCompositeSymbolProvider(
                         listOf(
-                            firProvider,
+                            firProvider.symbolProvider,
                             JavaSymbolProvider(this, sessionProvider.project, scope),
                             dependenciesProvider ?: FirDependenciesSymbolProviderImpl(this)
                         )

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/providers/FirProvider.kt

@@ -5,31 +5,26 @@
 
 package org.jetbrains.kotlin.fir.resolve.providers
 
+import org.jetbrains.kotlin.fir.FirSessionComponent
 import org.jetbrains.kotlin.fir.declarations.*
 import org.jetbrains.kotlin.fir.symbols.impl.FirCallableSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirClassLikeSymbol
 import org.jetbrains.kotlin.name.ClassId
 import org.jetbrains.kotlin.name.FqName
-import org.jetbrains.kotlin.name.Name
 
 @RequiresOptIn
 annotation class FirProviderInternals
 
-abstract class FirProvider : FirSymbolProvider() {
+abstract class FirProvider : FirSessionComponent {
+    /**
+     * [symbolProvider] for [FirProvider] may provide only symbols from sources of current module
+     */
+    abstract val symbolProvider: FirSymbolProvider
 
     open val isPhasedFirAllowed: Boolean get() = false
 
     abstract fun getFirClassifierByFqName(classId: ClassId): FirClassLikeDeclaration<*>?
 
-    abstract override fun getClassLikeSymbolByFqName(classId: ClassId): FirClassLikeSymbol<*>?
-
-    abstract override fun getTopLevelCallableSymbols(packageFqName: FqName, name: Name): List<FirCallableSymbol<*>>
-
-    override fun getPackage(fqName: FqName): FqName? {
-        if (getFirFilesByPackage(fqName).isNotEmpty()) return fqName
-        return null
-    }
-
     abstract fun getFirClassifierContainerFile(fqName: ClassId): FirFile
 
     abstract fun getFirClassifierContainerFileIfAny(fqName: ClassId): FirFile?

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/providers/impl/FirProviderImpl.kt

@@ -12,6 +12,7 @@ import org.jetbrains.kotlin.fir.declarations.*
 import org.jetbrains.kotlin.fir.declarations.synthetic.FirSyntheticProperty
 import org.jetbrains.kotlin.fir.resolve.providers.FirProvider
 import org.jetbrains.kotlin.fir.resolve.providers.FirProviderInternals
+import org.jetbrains.kotlin.fir.resolve.providers.FirSymbolProvider
 import org.jetbrains.kotlin.fir.scopes.FirScope
 import org.jetbrains.kotlin.fir.scopes.KotlinScopeProvider
 import org.jetbrains.kotlin.fir.scopes.impl.nestedClassifierScope
@@ -23,6 +24,8 @@ import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.name.Name
 
 class FirProviderImpl(val session: FirSession, val kotlinScopeProvider: KotlinScopeProvider) : FirProvider() {
+    override val symbolProvider: FirSymbolProvider = SymbolProvider()
+
     override fun getFirCallableContainerFile(symbol: FirCallableSymbol<*>): FirFile? {
         symbol.overriddenSymbol?.let {
             return getFirCallableContainerFile(it)
@@ -36,6 +39,19 @@ class FirProviderImpl(val session: FirSession, val kotlinScopeProvider: KotlinSc
         return state.callableContainerMap[symbol]
     }
 
+    override fun getFirClassifierContainerFile(fqName: ClassId): FirFile {
+        return state.classifierContainerFileMap[fqName] ?: error("Couldn't find container for $fqName")
+    }
+
+    override fun getFirClassifierContainerFileIfAny(fqName: ClassId): FirFile? {
+        return state.classifierContainerFileMap[fqName]
+    }
+
+    fun recordFile(file: FirFile) {
+        recordFile(file, state)
+    }
+
+    private inner class SymbolProvider : FirSymbolProvider() {
         override fun getClassLikeSymbolByFqName(classId: ClassId): FirClassLikeSymbol<*>? {
             return getFirClassifierByFqName(classId)?.symbol
         }
@@ -50,20 +66,14 @@ class FirProviderImpl(val session: FirSession, val kotlinScopeProvider: KotlinSc
             }
         }
 
-    override fun getFirClassifierContainerFile(fqName: ClassId): FirFile {
+        override fun getPackage(fqName: FqName): FqName? {
-        return state.classifierContainerFileMap[fqName] ?: error("Couldn't find container for $fqName")
+            if (getFirFilesByPackage(fqName).isNotEmpty()) return fqName
-    }
+            return null
-
-    override fun getFirClassifierContainerFileIfAny(fqName: ClassId): FirFile? {
-        return state.classifierContainerFileMap[fqName]
         }
 
         override fun getClassNamesInPackage(fqName: FqName): Set<Name> {
             return state.classesInPackage[fqName] ?: emptySet()
         }
-
-    fun recordFile(file: FirFile) {
-        recordFile(file, state)
     }
 
     @FirProviderInternals

idea/idea-frontend-fir/idea-fir-low-level-api/src/org/jetbrains/kotlin/idea/fir/low/level/api/FirIdeJavaModuleBasedSession.kt

@@ -82,7 +82,7 @@ internal class FirIdeJavaModuleBasedSession private constructor(
                     FirCompositeSymbolProvider(
                         @OptIn(ExperimentalStdlibApi::class)
                         buildList {
-                            add(provider)
+                            add(provider.symbolProvider)
                             add(JavaSymbolProvider(this@apply, sessionProvider.project, searchScope))
                             add(librariesSession.firSymbolProvider)
                         }

idea/idea-frontend-fir/idea-fir-low-level-api/src/org/jetbrains/kotlin/idea/fir/low/level/api/providers/FirIdeProvider.kt

@@ -13,6 +13,7 @@ import org.jetbrains.kotlin.fir.declarations.*
 import org.jetbrains.kotlin.fir.declarations.synthetic.FirSyntheticProperty
 import org.jetbrains.kotlin.fir.resolve.providers.FirProvider
 import org.jetbrains.kotlin.fir.resolve.providers.FirProviderInternals
+import org.jetbrains.kotlin.fir.resolve.providers.FirSymbolProvider
 import org.jetbrains.kotlin.fir.scopes.FirScope
 import org.jetbrains.kotlin.fir.scopes.KotlinScopeProvider
 import org.jetbrains.kotlin.fir.symbols.impl.FirAccessorSymbol
@@ -38,6 +39,8 @@ internal class FirIdeProvider(
     val cache: ModuleFileCache,
     searchScope: GlobalSearchScope,
 ) : FirProvider() {
+    override val symbolProvider: FirSymbolProvider = SymbolProvider()
+
     private val indexHelper = IndexHelper(project, searchScope)
     private val packageExistenceChecker = PackageExistenceCheckerForMultipleModules(
         project,
@@ -56,19 +59,6 @@ internal class FirIdeProvider(
     override fun getFirClassifierByFqName(classId: ClassId): FirClassLikeDeclaration<*>? =
         providerHelper.getFirClassifierByFqName(classId)
 
-    override fun getTopLevelCallableSymbols(packageFqName: FqName, name: Name): List<FirCallableSymbol<*>> =
-        providerHelper.getTopLevelCallableSymbols(packageFqName, name)
-
-    override fun getPackage(fqName: FqName): FqName? =
-        providerHelper.getPackage(fqName)
-
-    override fun getNestedClassifierScope(classId: ClassId): FirScope? =
-        providerHelper.getNestedClassifierScope(classId)
-
-    override fun getClassLikeSymbolByFqName(classId: ClassId): FirClassLikeSymbol<*>? {
-        return getFirClassifierByFqName(classId)?.symbol
-    }
-
     override fun getFirClassifierContainerFile(fqName: ClassId): FirFile {
         return getFirClassifierContainerFileIfAny(fqName)
             ?: error("Couldn't find container for ${fqName}")
@@ -121,6 +111,20 @@ internal class FirIdeProvider(
         TODO()
     }
 
+    private inner class SymbolProvider : FirSymbolProvider() {
+        override fun getTopLevelCallableSymbols(packageFqName: FqName, name: Name): List<FirCallableSymbol<*>> =
+            providerHelper.getTopLevelCallableSymbols(packageFqName, name)
+
+        override fun getPackage(fqName: FqName): FqName? =
+            providerHelper.getPackage(fqName)
+
+        override fun getNestedClassifierScope(classId: ClassId): FirScope? =
+            providerHelper.getNestedClassifierScope(classId)
+
+        override fun getClassLikeSymbolByFqName(classId: ClassId): FirClassLikeSymbol<*>? {
+            return getFirClassifierByFqName(classId)?.symbol
+        }
+
         // TODO this should be reworked because [FirIdeProvider] should not have such method
         // used only in completion
         override fun getAllCallableNamesInPackage(fqName: FqName): Set<Name> {
@@ -129,6 +133,7 @@ internal class FirIdeProvider(
                 indexHelper.getTopLevelFunctionsInPackage(fqName).mapNotNullTo(this) { it.nameAsName }
             }
         }
+    }
 }
 
 internal val FirSession.firIdeProvider: FirIdeProvider by FirSession.sessionComponentAccessor()