From 7ad4e58a7a2971eb3f379a652ae3449ed41bbcc3 Mon Sep 17 00:00:00 2001
From: Sergej Jaskiewicz <sergej.jaskiewicz@jetbrains.com>
Date: Thu, 14 Mar 2024 18:26:13 +0100
Subject: [PATCH] [FIR tree generator] Add a kDoc for FirUnitExpression

---
 .../kotlin/fir/expressions/impl/FirUnitExpression.kt      | 6 +++++-
 .../fir/tree/generator/ImplementationConfigurator.kt      | 8 +++++++-
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/compiler/fir/tree/gen/org/jetbrains/kotlin/fir/expressions/impl/FirUnitExpression.kt b/compiler/fir/tree/gen/org/jetbrains/kotlin/fir/expressions/impl/FirUnitExpression.kt
index bb7726e176c..5e9fb82e0e1 100644
--- a/compiler/fir/tree/gen/org/jetbrains/kotlin/fir/expressions/impl/FirUnitExpression.kt
+++ b/compiler/fir/tree/gen/org/jetbrains/kotlin/fir/expressions/impl/FirUnitExpression.kt
@@ -16,15 +16,19 @@ import org.jetbrains.kotlin.fir.MutableOrEmptyList
 import org.jetbrains.kotlin.fir.builder.toMutableOrEmpty
 import org.jetbrains.kotlin.fir.expressions.FirAnnotation
 import org.jetbrains.kotlin.fir.expressions.FirExpression
+import org.jetbrains.kotlin.fir.expressions.FirReturnExpression
 import org.jetbrains.kotlin.fir.expressions.UnresolvedExpressionTypeAccess
 import org.jetbrains.kotlin.fir.types.ConeKotlinType
 import org.jetbrains.kotlin.fir.types.constructClassLikeType
-import org.jetbrains.kotlin.fir.types.impl.FirImplicitUnitTypeRef
 import org.jetbrains.kotlin.fir.visitors.FirTransformer
 import org.jetbrains.kotlin.fir.visitors.FirVisitor
 import org.jetbrains.kotlin.fir.visitors.transformInplace
 import org.jetbrains.kotlin.name.StandardClassIds
 
+/**
+ * A special kind of expression that can only appear inside [FirReturnExpression].
+ * It denotes an empty `return` expression, which is different from explicit `return Unit`.
+ */
 class FirUnitExpression @FirImplementationDetail constructor(
     override val source: KtSourceElement?,
     override var annotations: MutableOrEmptyList<FirAnnotation>,
diff --git a/compiler/fir/tree/tree-generator/src/org/jetbrains/kotlin/fir/tree/generator/ImplementationConfigurator.kt b/compiler/fir/tree/tree-generator/src/org/jetbrains/kotlin/fir/tree/generator/ImplementationConfigurator.kt
index 82989efecc2..06e9a4c04d5 100644
--- a/compiler/fir/tree/tree-generator/src/org/jetbrains/kotlin/fir/tree/generator/ImplementationConfigurator.kt
+++ b/compiler/fir/tree/tree-generator/src/org/jetbrains/kotlin/fir/tree/generator/ImplementationConfigurator.kt
@@ -371,8 +371,14 @@ object ImplementationConfigurator : AbstractFirTreeImplementationConfigurator()
         }
 
         impl(expression, "FirUnitExpression") {
+            kDoc(
+                """
+                A special kind of expression that can only appear inside [${returnExpression.typeName}].
+                It denotes an empty `return` expression, which is different from explicit `return Unit`.
+                """.trimIndent()
+            )
             defaultBuiltInType("Unit")
-            additionalImports(implicitUnitTypeRefType)
+            additionalImports(returnExpression)
             publicImplementation()
         }