FIR: Get rid of usages of FirCallableSymbol::overriddenSymbol

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.ThreadSafeMutableState
 import org.jetbrains.kotlin.fir.builder.RawFirBuilder
 import org.jetbrains.kotlin.fir.declarations.*
 import org.jetbrains.kotlin.fir.declarations.synthetic.FirSyntheticProperty
+import org.jetbrains.kotlin.fir.originalForSubstitutionOverride
 import org.jetbrains.kotlin.fir.resolve.providers.FirProvider
 import org.jetbrains.kotlin.fir.resolve.providers.FirProviderInternals
 import org.jetbrains.kotlin.fir.resolve.providers.FirSymbolProvider
@@ -79,7 +80,7 @@ internal class FirIdeProvider(
 
 
     override fun getFirCallableContainerFile(symbol: FirCallableSymbol<*>): FirFile? {
-        symbol.overriddenSymbol?.let {
+        symbol.fir.originalForSubstitutionOverride?.symbol?.let {
             return getFirCallableContainerFile(it)
         }
         if (symbol is FirAccessorSymbol) {

idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/fir/FirIdeDeserializedDeclarationSourceProvider.kt

@@ -8,11 +8,8 @@ package org.jetbrains.kotlin.idea.fir
 import com.intellij.openapi.project.Project
 import com.intellij.psi.PsiElement
 import com.intellij.psi.search.GlobalSearchScope
-import org.jetbrains.kotlin.fir.FirElement
-import org.jetbrains.kotlin.fir.FirSession
-import org.jetbrains.kotlin.fir.containingClass
+import org.jetbrains.kotlin.fir.*
 import org.jetbrains.kotlin.fir.declarations.*
-import org.jetbrains.kotlin.fir.psi
 import org.jetbrains.kotlin.idea.fir.low.level.api.sessions.FirIdeSession
 import org.jetbrains.kotlin.idea.stubindex.KotlinFullClassNameIndex
 import org.jetbrains.kotlin.idea.stubindex.KotlinTopLevelFunctionFqnNameIndex
@@ -53,7 +50,7 @@ object FirIdeDeserializedDeclarationSourceProvider {
                 .orEmpty()
         }
 
-        return function.unrollFakeOverrides().chooseCorrespondingPsi(candidates)
+        return function.unwrapFakeOverrides().chooseCorrespondingPsi(candidates)
     }
 
     private fun provideSourceForProperty(property: FirProperty, project: Project): PsiElement? {
@@ -91,7 +88,7 @@ object FirIdeDeserializedDeclarationSourceProvider {
         val containingKtClass = constructor.containingKtClass(project) ?: return null
         if (constructor.isPrimary) return containingKtClass.primaryConstructor
 
-        return constructor.unrollFakeOverrides().chooseCorrespondingPsi(containingKtClass.secondaryConstructors)
+        return constructor.unwrapFakeOverrides().chooseCorrespondingPsi(containingKtClass.secondaryConstructors)
     }
 
     private fun FirFunction<*>.chooseCorrespondingPsi(
@@ -117,7 +114,7 @@ object FirIdeDeserializedDeclarationSourceProvider {
     }
 
     private fun FirCallableDeclaration<*>.containingKtClass(project: Project): KtClassOrObject? =
-        unrollFakeOverrides().containingClass()?.classId?.let { classByClassId(it, scope(project), project) }
+        unwrapFakeOverrides().containingClass()?.classId?.let { classByClassId(it, scope(project), project) }
 
     private fun classByClassId(classId: ClassId, scope: GlobalSearchScope, project: Project): KtClassOrObject? {
         val fqName = classId.asStringForUsingInIndexes().let { classIdMapping[it] ?: it }

idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/fir/FirUtils.kt

@@ -5,17 +5,12 @@
 
 package org.jetbrains.kotlin.idea.fir
 
-import org.jetbrains.kotlin.fir.FirSymbolOwner
-import org.jetbrains.kotlin.fir.declarations.FirCallableDeclaration
 import org.jetbrains.kotlin.fir.declarations.FirDeclaration
 import org.jetbrains.kotlin.fir.expressions.FirFunctionCall
 import org.jetbrains.kotlin.fir.expressions.FirQualifiedAccessExpression
-import org.jetbrains.kotlin.fir.isIntersectionOverride
-import org.jetbrains.kotlin.fir.isSubstitutionOverride
 import org.jetbrains.kotlin.fir.references.FirReference
 import org.jetbrains.kotlin.fir.references.FirResolvedNamedReference
 import org.jetbrains.kotlin.fir.symbols.FirBasedSymbol
-import org.jetbrains.kotlin.fir.symbols.PossiblyFirFakeOverrideSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirNamedFunctionSymbol
 import org.jetbrains.kotlin.idea.frontend.api.fir.KtSymbolByFirBuilder
 import org.jetbrains.kotlin.idea.frontend.api.symbols.KtSymbol
@@ -38,20 +33,3 @@ internal fun FirReference.getResolvedKtSymbolOfNameReference(builder: KtSymbolBy
     (getResolvedSymbolOfNameReference()?.fir as? FirDeclaration)?.let { firDeclaration ->
         builder.buildSymbol(firDeclaration)
     }
-
-internal inline fun <reified D> D.unrollFakeOverrides(): D where D : FirDeclaration, D : FirSymbolOwner<*> {
-    val symbol = symbol
-    if (symbol !is PossiblyFirFakeOverrideSymbol<*, *>) return this
-    if (!symbol.isFakeOrIntersectionOverride) return this
-    var current: FirBasedSymbol<*>? = symbol.overriddenSymbol
-    while (current is PossiblyFirFakeOverrideSymbol<*, *> && current.isFakeOrIntersectionOverride) {
-        current = current.overriddenSymbol
-    }
-    return current?.fir as D
-}
-
-private inline val FirBasedSymbol<*>.isFakeOrIntersectionOverride: Boolean
-    get() {
-        val declaration = fir as? FirCallableDeclaration<*> ?: return false
-        return declaration.isSubstitutionOverride || declaration.isIntersectionOverride
-    }

idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/frontend/api/fir/symbols/KtFirSymbol.kt

@@ -5,11 +5,12 @@
 
 package org.jetbrains.kotlin.idea.frontend.api.fir.symbols
 
+import org.jetbrains.kotlin.fir.declarations.FirCallableDeclaration
 import org.jetbrains.kotlin.fir.declarations.FirDeclaration
 import org.jetbrains.kotlin.fir.declarations.FirDeclarationOrigin
+import org.jetbrains.kotlin.fir.originalIfFakeOverride
 import org.jetbrains.kotlin.idea.frontend.api.ValidityTokenOwner
 import org.jetbrains.kotlin.idea.frontend.api.fir.utils.FirRefWithValidityCheck
-import org.jetbrains.kotlin.idea.frontend.api.fir.utils.overriddenDeclaration
 import org.jetbrains.kotlin.idea.frontend.api.symbols.KtSymbol
 import org.jetbrains.kotlin.idea.frontend.api.symbols.KtSymbolOrigin
 
@@ -27,10 +28,11 @@ private tailrec fun FirDeclaration.ktSymbolOrigin(): KtSymbolOrigin = when (orig
     FirDeclarationOrigin.SamConstructor -> KtSymbolOrigin.SAM_CONSTRUCTOR
     FirDeclarationOrigin.Enhancement -> KtSymbolOrigin.JAVA
     else -> {
-        val overridden = overriddenDeclaration ?: throw InvalidFirDeclarationOriginForSymbol(origin)
+        val overridden =
+            (this as? FirCallableDeclaration<*>)?.originalIfFakeOverride() ?: throw InvalidFirDeclarationOriginForSymbol(origin)
         overridden.ktSymbolOrigin()
     }
 }
 
 class InvalidFirDeclarationOriginForSymbol(origin: FirDeclarationOrigin) :
-    IllegalStateException("Invalid FirDeclarationOrigin  $origin")
+    IllegalStateException("Invalid FirDeclarationOrigin  $origin")

idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/frontend/api/fir/utils/firUtils.kt

@@ -1,15 +0,0 @@
-/*
- * Copyright 2010-2020 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.idea.frontend.api.fir.utils
-
-import org.jetbrains.kotlin.fir.FirSymbolOwner
-import org.jetbrains.kotlin.fir.declarations.FirDeclaration
-import org.jetbrains.kotlin.fir.symbols.impl.FirCallableSymbol
-
-internal inline val FirDeclaration.overriddenDeclaration: FirDeclaration?
-    get() {
-        val symbol = (this as? FirSymbolOwner<*>)?.symbol ?: return null
-        return (symbol as? FirCallableSymbol)?.overriddenSymbol?.fir as? FirDeclaration
-    }