From c602ccb33ef3b9febe4dbc4a47f58de4a261cfc3 Mon Sep 17 00:00:00 2001
From: Mikhail Glukhikh <mikhail.glukhikh@jetbrains.com>
Date: Tue, 17 Nov 2020 18:40:33 +0300
Subject: [PATCH] Create FIR fake source element for vararg argument expression

---
 .../fir/resolve/transformers/body/resolve/BodyResolveUtils.kt | 2 +-
 .../fir/tree/src/org/jetbrains/kotlin/fir/FirSourceElement.kt | 4 ++++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/body/resolve/BodyResolveUtils.kt b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/body/resolve/BodyResolveUtils.kt
index 1ea0276fd73..3d1c7d0aff2 100644
--- a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/body/resolve/BodyResolveUtils.kt
+++ b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/body/resolve/BodyResolveUtils.kt
@@ -58,7 +58,7 @@ internal fun remapArgumentsWithVararg(
             ) {
                 arguments += arg
                 if (this.source == null) {
-                    this.source = arg.source
+                    this.source = arg.source?.fakeElement(FirFakeSourceElementKind.VarargArgument)
                 }
             } else if (arguments.isEmpty()) {
                 // `arg` is BEFORE the vararg arguments.
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 64951b8468d..b546acbe5c4 100644
--- a/compiler/fir/tree/src/org/jetbrains/kotlin/fir/FirSourceElement.kt
+++ b/compiler/fir/tree/src/org/jetbrains/kotlin/fir/FirSourceElement.kt
@@ -150,6 +150,10 @@ sealed class FirFakeSourceElementKind : FirSourceElementKind() {
     // super.foo() --> super<Supertype>.foo()
     // where `Supertype` has a fake source
     object SuperCallImplicitType : FirFakeSourceElementKind()
+
+    // fun foo(vararg args: Int) {}
+    // fun bar(1, 2, 3) --> [resolved] fun bar(VarargArgument(1, 2, 3))
+    object VarargArgument : FirFakeSourceElementKind()
 }
 
 sealed class FirSourceElement {