FIR: visit/transform dispatch & extension receivers only once

compiler/fir/tree/src/org/jetbrains/kotlin/fir/expressions/FirQualifiedAccess.kt

@@ -30,8 +30,12 @@ interface FirQualifiedAccess : FirResolvable {
     override fun <R, D> acceptChildren(visitor: FirVisitor<R, D>, data: D) {
         calleeReference.accept(visitor, data)
         explicitReceiver?.accept(visitor, data)
-        dispatchReceiver.accept(visitor, data)
-        extensionReceiver.accept(visitor, data)
+        if (dispatchReceiver !== explicitReceiver) {
+            dispatchReceiver.accept(visitor, data)
+        }
+        if (extensionReceiver !== explicitReceiver && extensionReceiver !== dispatchReceiver) {
+            extensionReceiver.accept(visitor, data)
+        }
         super.acceptChildren(visitor, data)
     }
 

compiler/fir/tree/src/org/jetbrains/kotlin/fir/expressions/impl/FirAbstractQualifiedAccess.kt

@@ -24,21 +24,8 @@ abstract class FirAbstractQualifiedAccess(
     override var extensionReceiver: FirExpression = FirNoReceiverExpression
 
     override fun <D> transformChildren(transformer: FirTransformer<D>, data: D): FirElement {
-        calleeReference = calleeReference.transformSingle(transformer, data)
-        explicitReceiver = explicitReceiver?.transformSingle(transformer, data)
-        dispatchReceiver = dispatchReceiver.transformSingle(transformer, data)
-        extensionReceiver = extensionReceiver.transformSingle(transformer, data)
+        super<FirModifiableQualifiedAccess>.transformChildren(transformer, data)
 
         return super<FirAnnotatedStatement>.transformChildren(transformer, data)
     }
-
-    override fun <D> transformCalleeReference(transformer: FirTransformer<D>, data: D): FirQualifiedAccess {
-        calleeReference = calleeReference.transformSingle(transformer, data)
-        return this
-    }
-
-    override fun <D> transformExplicitReceiver(transformer: FirTransformer<D>, data: D): FirQualifiedAccess {
-        explicitReceiver = explicitReceiver?.transformSingle(transformer, data)
-        return this
-    }
 }

compiler/fir/tree/src/org/jetbrains/kotlin/fir/expressions/impl/FirFunctionCallImpl.kt

@@ -29,10 +29,7 @@ class FirFunctionCallImpl(
 
     override fun <D> transformChildren(transformer: FirTransformer<D>, data: D): FirElement {
         typeArguments.transformInplace(transformer, data)
-        calleeReference = calleeReference.transformSingle(transformer, data)
-        explicitReceiver = explicitReceiver?.transformSingle(transformer, data)
-        dispatchReceiver = dispatchReceiver.transformSingle(transformer, data)
-        extensionReceiver = extensionReceiver.transformSingle(transformer, data)
+        super<FirModifiableQualifiedAccess>.transformChildren(transformer, data)
 
         return super<FirFunctionCall>.transformChildren(transformer, data)
     }

compiler/fir/tree/src/org/jetbrains/kotlin/fir/expressions/impl/FirModifiableQualifiedAccess.kt

@@ -5,9 +5,12 @@
 
 package org.jetbrains.kotlin.fir.expressions.impl
 
+import org.jetbrains.kotlin.fir.FirElement
 import org.jetbrains.kotlin.fir.FirReference
 import org.jetbrains.kotlin.fir.expressions.FirExpression
+import org.jetbrains.kotlin.fir.expressions.FirFunctionCall
 import org.jetbrains.kotlin.fir.expressions.FirQualifiedAccess
+import org.jetbrains.kotlin.fir.transformInplace
 import org.jetbrains.kotlin.fir.transformSingle
 import org.jetbrains.kotlin.fir.visitors.FirTransformer
 
@@ -47,4 +50,18 @@ interface FirModifiableQualifiedAccess<C : FirReference> : FirQualifiedAccess {
         extensionReceiver = extensionReceiver.transformSingle(transformer, data)
         return this
     }
+
+    override fun <D> transformChildren(transformer: FirTransformer<D>, data: D): FirElement {
+        calleeReference = calleeReference.transformSingle(transformer, data)
+        explicitReceiver = explicitReceiver?.transformSingle(transformer, data)
+        if (dispatchReceiver !== explicitReceiver) {
+            dispatchReceiver = dispatchReceiver.transformSingle(transformer, data)
+        }
+        if (extensionReceiver !== explicitReceiver && extensionReceiver !== dispatchReceiver) {
+            extensionReceiver = extensionReceiver.transformSingle(transformer, data)
+        }
+
+        return this
+    }
+
 }

compiler/fir/tree/src/org/jetbrains/kotlin/fir/expressions/impl/FirQualifiedAccessExpressionImpl.kt

@@ -26,10 +26,7 @@ class FirQualifiedAccessExpressionImpl(
     override var extensionReceiver: FirExpression = FirNoReceiverExpression
 
     override fun <D> transformChildren(transformer: FirTransformer<D>, data: D): FirElement {
-        calleeReference = calleeReference.transformSingle(transformer, data)
-        explicitReceiver = explicitReceiver?.transformSingle(transformer, data)
-        dispatchReceiver = dispatchReceiver.transformSingle(transformer, data)
-        extensionReceiver = extensionReceiver.transformSingle(transformer, data)
+        super<FirModifiableQualifiedAccess>.transformChildren(transformer, data)
 
         return super<FirQualifiedAccessExpression>.transformChildren(transformer, data)
     }