From 19d11f9149b109dd245ee24a352ffb85b76c5ac1 Mon Sep 17 00:00:00 2001
From: Roman Golyshev <roman.golyshev@jetbrains.com>
Date: Mon, 6 Sep 2021 20:03:18 +0300
Subject: [PATCH] [FIR IDE] Do not create `KtPsiBasedSymbolPointer` for
 generated members

For example, if a class has default constructor (`class Foo`),
both KtClassSymbol and KtConstructorSymbol will be pointing to the same
PSI - thus creating effectively the same `KtSymbolPointer`. Later
it will be impossible to deduce which symbol we had in mind

Currently, `Show Parameters Info` works incorrectly for
such generated declarations  because of that - it throws CCE while
trying to cast class symbol to function (constructor) symbol
---
 .../kotlin/idea/frontend/api/symbols/KtSymbol.kt   |  1 +
 .../symbols/pointers/KtPsiBasedSymbolPointer.kt    |  7 +++++++
 .../idea/frontend/api/fir/symbols/KtFirSymbol.kt   | 14 ++++++++------
 3 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/idea/idea-frontend-api/src/org/jetbrains/kotlin/idea/frontend/api/symbols/KtSymbol.kt b/idea/idea-frontend-api/src/org/jetbrains/kotlin/idea/frontend/api/symbols/KtSymbol.kt
index 2f37a13179d..2e1c7cbea00 100644
--- a/idea/idea-frontend-api/src/org/jetbrains/kotlin/idea/frontend/api/symbols/KtSymbol.kt
+++ b/idea/idea-frontend-api/src/org/jetbrains/kotlin/idea/frontend/api/symbols/KtSymbol.kt
@@ -51,6 +51,7 @@ public enum class KtSymbolOrigin {
 
     /**
      * Declaration which do not have it's PSI source and was generated, they are:
+     * For regular classes, implicit default constructor is generated
      * For data classes the `copy`, `component{N}`, `toString`, `equals`, `hashCode` functions are generated
      * For enum classes the `valueOf` & `values` functions are generated
      * For lambda the `it` property is generated
diff --git a/idea/idea-frontend-api/src/org/jetbrains/kotlin/idea/frontend/api/symbols/pointers/KtPsiBasedSymbolPointer.kt b/idea/idea-frontend-api/src/org/jetbrains/kotlin/idea/frontend/api/symbols/pointers/KtPsiBasedSymbolPointer.kt
index 8c7e9cff239..d610a8a38d0 100644
--- a/idea/idea-frontend-api/src/org/jetbrains/kotlin/idea/frontend/api/symbols/pointers/KtPsiBasedSymbolPointer.kt
+++ b/idea/idea-frontend-api/src/org/jetbrains/kotlin/idea/frontend/api/symbols/pointers/KtPsiBasedSymbolPointer.kt
@@ -26,6 +26,13 @@ public class KtPsiBasedSymbolPointer<S : KtSymbol>(private val psiPointer: Smart
     public companion object {
         public fun <S : KtSymbol> createForSymbolFromSource(symbol: S): KtPsiBasedSymbolPointer<S>? {
             if (symbol.origin == KtSymbolOrigin.LIBRARY) return null
+
+            /**
+             * If symbol points to a generated member, we won't be able to recover it later on, because there is no corresponding
+             * psi by which it can be found
+             */
+            if (symbol.origin == KtSymbolOrigin.SOURCE_MEMBER_GENERATED) return null
+
             val psi = when (val psi = symbol.psi) {
                 is KtDeclaration -> psi
                 is KtObjectLiteralExpression -> psi.objectDeclaration
diff --git a/idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/frontend/api/fir/symbols/KtFirSymbol.kt b/idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/frontend/api/fir/symbols/KtFirSymbol.kt
index fb68c001790..974c4ce7468 100644
--- a/idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/frontend/api/fir/symbols/KtFirSymbol.kt
+++ b/idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/frontend/api/fir/symbols/KtFirSymbol.kt
@@ -34,12 +34,14 @@ internal fun KtFirSymbol<*>.symbolHashCode(): Int = firRef.hashCode() * 31 + tok
 
 private tailrec fun FirDeclaration.ktSymbolOrigin(): KtSymbolOrigin = when (origin) {
     FirDeclarationOrigin.Source -> {
-        if (source?.kind == FirFakeSourceElementKind.DataClassGeneratedMembers
-            || source?.kind == FirFakeSourceElementKind.EnumGeneratedDeclaration
-            || source?.kind == FirFakeSourceElementKind.ItLambdaParameter
-        ) {
-            KtSymbolOrigin.SOURCE_MEMBER_GENERATED
-        } else KtSymbolOrigin.SOURCE
+        when (source?.kind) {
+            FirFakeSourceElementKind.ImplicitConstructor,
+            FirFakeSourceElementKind.DataClassGeneratedMembers,
+            FirFakeSourceElementKind.EnumGeneratedDeclaration,
+            FirFakeSourceElementKind.ItLambdaParameter -> KtSymbolOrigin.SOURCE_MEMBER_GENERATED
+
+            else -> KtSymbolOrigin.SOURCE
+        }
     }
     FirDeclarationOrigin.Library, FirDeclarationOrigin.BuiltIns -> KtSymbolOrigin.LIBRARY
     FirDeclarationOrigin.Java -> KtSymbolOrigin.JAVA