From 22054c8507d32e8763ffb48534e84d06675e4948 Mon Sep 17 00:00:00 2001
From: Ilya Kirillov <ilya.kirillov@jetbrains.com>
Date: Tue, 7 Jul 2020 22:16:42 +0300
Subject: [PATCH] FIR IDE: use non-fake override fir elements when finding psi
 for fir

---
 ...irIdeDeserializedDeclarationSourceProvider.kt |  5 +++--
 .../org/jetbrains/kotlin/idea/fir/FirUtils.kt    | 16 +++++++++++++++-
 .../inStandardLibrary/notNull.kt                 |  4 ++--
 3 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/fir/FirIdeDeserializedDeclarationSourceProvider.kt b/idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/fir/FirIdeDeserializedDeclarationSourceProvider.kt
index 625fe127ad1..b15006d32b2 100644
--- a/idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/fir/FirIdeDeserializedDeclarationSourceProvider.kt
+++ b/idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/fir/FirIdeDeserializedDeclarationSourceProvider.kt
@@ -12,6 +12,7 @@ import org.jetbrains.kotlin.fir.FirElement
 import org.jetbrains.kotlin.fir.FirSession
 import org.jetbrains.kotlin.fir.declarations.*
 import org.jetbrains.kotlin.fir.psi
+import org.jetbrains.kotlin.fir.symbols.PossiblyFirFakeOverrideSymbol
 import org.jetbrains.kotlin.idea.stubindex.KotlinFullClassNameIndex
 import org.jetbrains.kotlin.idea.stubindex.KotlinTopLevelFunctionFqnNameIndex
 import org.jetbrains.kotlin.idea.stubindex.KotlinTopLevelTypeAliasFqNameIndex
@@ -51,7 +52,7 @@ object FirIdeDeserializedDeclarationSourceProvider {
                 .orEmpty()
         }
 
-        return function.chooseCorrespondingPsi(candidates)
+        return function.unrollFakeOverrides().chooseCorrespondingPsi(candidates)
     }
 
     private fun provideSourceForProperty(property: FirProperty, project: Project): PsiElement? {
@@ -89,7 +90,7 @@ object FirIdeDeserializedDeclarationSourceProvider {
         val containingKtClass = constructor.containingKtClass(project) ?: return null
         if (constructor.isPrimary) return containingKtClass.primaryConstructor
 
-        return constructor.chooseCorrespondingPsi(containingKtClass.secondaryConstructors)
+        return constructor.unrollFakeOverrides().chooseCorrespondingPsi(containingKtClass.secondaryConstructors)
     }
 
     private fun FirFunction<*>.chooseCorrespondingPsi(
diff --git a/idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/fir/FirUtils.kt b/idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/fir/FirUtils.kt
index 0b4d09e08ad..a83a9a4b10c 100644
--- a/idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/fir/FirUtils.kt
+++ b/idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/fir/FirUtils.kt
@@ -6,12 +6,15 @@
 package org.jetbrains.kotlin.idea.fir
 
 import org.jetbrains.kotlin.fir.FirElement
+import org.jetbrains.kotlin.fir.FirSymbolOwner
+import org.jetbrains.kotlin.fir.declarations.FirDeclaration
 import org.jetbrains.kotlin.fir.declarations.FirResolvePhase
 import org.jetbrains.kotlin.fir.expressions.FirFunctionCall
 import org.jetbrains.kotlin.fir.expressions.FirQualifiedAccessExpression
 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.fir.low.level.api.FirModuleResolveState
 import org.jetbrains.kotlin.idea.fir.low.level.api.LowLevelFirApiFacade
@@ -58,4 +61,15 @@ fun FirFunctionCall.getCalleeSymbol(): FirBasedSymbol<*>? =
     calleeReference.getResolvedSymbolOfNameReference()
 
 fun FirReference.getResolvedSymbolOfNameReference(): FirBasedSymbol<*>? =
-    (this as? FirResolvedNamedReference)?.resolvedSymbol
\ No newline at end of file
+    (this as? FirResolvedNamedReference)?.resolvedSymbol
+
+inline fun <reified D> D.unrollFakeOverrides(): D where D : FirDeclaration, D : FirSymbolOwner<D> {
+    val symbol = symbol
+    if (symbol !is PossiblyFirFakeOverrideSymbol<*, *>) return this
+    if (!symbol.isFakeOverride) return this
+    var current: FirBasedSymbol<*>? = symbol.overriddenSymbol
+    while (current is PossiblyFirFakeOverrideSymbol<*, *> && current.isFakeOverride) {
+        current = current.overriddenSymbol
+    }
+    return current?.fir as D
+}
diff --git a/idea/testData/resolve/references/delegatedPropertyAccessors/inStandardLibrary/notNull.kt b/idea/testData/resolve/references/delegatedPropertyAccessors/inStandardLibrary/notNull.kt
index 324ac6b0e90..263685a487b 100644
--- a/idea/testData/resolve/references/delegatedPropertyAccessors/inStandardLibrary/notNull.kt
+++ b/idea/testData/resolve/references/delegatedPropertyAccessors/inStandardLibrary/notNull.kt
@@ -1,7 +1,7 @@
-// IGNORE_FIR
-
 import kotlin.properties.Delegates
 
 var x: Int <caret>by Delegates.notNull()
 
+// MULTIRESOLVE
+// REF: (in kotlin.properties.ReadWriteProperty).getValue(T, kotlin.reflect.KProperty<*>)
 // REF: (in kotlin.properties.ReadWriteProperty).setValue(T, kotlin.reflect.KProperty<*>, V)