From cbc9d0862388819a1df2dbbe8c991aaae77869ee Mon Sep 17 00:00:00 2001
From: Tianyu Geng <tgeng@google.com>
Date: Mon, 11 Oct 2021 13:51:22 -0700
Subject: [PATCH] FIR: [code clean up] force custom hashcode/equals for
 FirSourceElement

---
 .../tree/src/org/jetbrains/kotlin/fir/FirSourceElement.kt   | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/compiler/fir/tree/src/org/jetbrains/kotlin/fir/FirSourceElement.kt b/compiler/fir/tree/src/org/jetbrains/kotlin/fir/FirSourceElement.kt
index a9d38bf63f0..d778724cba6 100644
--- a/compiler/fir/tree/src/org/jetbrains/kotlin/fir/FirSourceElement.kt
+++ b/compiler/fir/tree/src/org/jetbrains/kotlin/fir/FirSourceElement.kt
@@ -197,6 +197,12 @@ sealed class FirSourceElement {
     abstract val kind: FirSourceElementKind
     abstract val lighterASTNode: LighterASTNode
     abstract val treeStructure: FlyweightCapableTreeStructure<LighterASTNode>
+
+    /** Implementation must compute the hashcode from the source element. */
+    abstract override fun hashCode(): Int
+
+    /** Elements of the same source should be considered equal. */
+    abstract override fun equals(other: Any?): Boolean
 }
 
 // NB: in certain situations, psi.node could be null