[FIR] Extract function for receiver resolution

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/FirCallResolver.kt

@@ -264,7 +264,7 @@ class FirCallResolver(
         val callee = qualifiedAccess.calleeReference as? FirSimpleNamedReference ?: return qualifiedAccess
 
         @Suppress("NAME_SHADOWING")
-        val qualifiedAccess = qualifiedAccess.let(transformer::transformExplicitReceiver)
+        val qualifiedAccess = qualifiedAccess.let(transformer::transformExplicitReceiverOf)
         val nonFatalDiagnosticFromExpression = (qualifiedAccess as? FirPropertyAccessExpression)?.nonFatalDiagnostics
 
         val basicResult by lazy(LazyThreadSafetyMode.NONE) {

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/body/resolve/FirExpressionsResolveTransformer.kt

@@ -199,8 +199,8 @@ open class FirExpressionsResolveTransformer(transformer: FirAbstractBodyResolveT
         return result
     }
 
-    fun <Q : FirQualifiedAccessExpression> transformExplicitReceiver(qualifiedAccessExpression: Q): Q {
+    fun <Q : FirQualifiedAccessExpression> transformExplicitReceiverOf(qualifiedAccessExpression: Q): Q {
-        val explicitReceiver = qualifiedAccessExpression.explicitReceiver as? FirQualifiedAccessExpression
+        val explicitReceiver = qualifiedAccessExpression.explicitReceiver
         if (explicitReceiver is FirQualifiedAccessExpression) {
             val superReference = explicitReceiver.calleeReference as? FirSuperReference
             if (superReference != null) {
@@ -208,16 +208,26 @@ open class FirExpressionsResolveTransformer(transformer: FirAbstractBodyResolveT
                 return qualifiedAccessExpression
             }
         }
-        if (explicitReceiver is FirPropertyAccessExpression) {
+
+        if (explicitReceiver != null) {
             qualifiedAccessExpression.replaceExplicitReceiver(
-                transformQualifiedAccessExpression(
+                explicitReceiver.transformAsExplicitReceiver(ResolutionMode.ReceiverResolution, isUsedAsGetClassReceiver = false)
-                    explicitReceiver, ResolutionMode.ReceiverResolution, isUsedAsReceiver = true, isUsedAsGetClassReceiver = false
-                )
             )
-            return qualifiedAccessExpression
         }
-        @Suppress("UNCHECKED_CAST")
+
-        return qualifiedAccessExpression.transformExplicitReceiver(transformer, ResolutionMode.ReceiverResolution) as Q
+        return qualifiedAccessExpression
+    }
+
+    private fun FirExpression.transformAsExplicitReceiver(
+        resolutionMode: ResolutionMode,
+        isUsedAsGetClassReceiver: Boolean,
+    ): FirExpression {
+        return when (this) {
+            is FirPropertyAccessExpression -> transformQualifiedAccessExpression(
+                this, resolutionMode, isUsedAsReceiver = true, isUsedAsGetClassReceiver = isUsedAsGetClassReceiver
+            )
+            else -> transformSingle(this@FirExpressionsResolveTransformer, resolutionMode)
+        }
     }
 
     override fun transformPropertyAccessExpression(
@@ -456,7 +466,7 @@ open class FirExpressionsResolveTransformer(transformer: FirAbstractBodyResolveT
                 // and 'someDelegate' explicit receiver is resolved at 1st stage
                 // See also FirDeclarationsResolveTransformer.transformWrappedDelegateExpression
                 val withResolvedExplicitReceiver =
-                    if (callResolutionMode == CallResolutionMode.PROVIDE_DELEGATE) functionCall else transformExplicitReceiver(functionCall)
+                    if (callResolutionMode == CallResolutionMode.PROVIDE_DELEGATE) functionCall else transformExplicitReceiverOf(functionCall)
                 withResolvedExplicitReceiver.also {
                     it.replaceArgumentList(it.argumentList.transform(this, ResolutionMode.ContextDependent))
                     dataFlowAnalyzer.exitCallArguments()
@@ -1101,18 +1111,13 @@ open class FirExpressionsResolveTransformer(transformer: FirAbstractBodyResolveT
 
         callableReferenceAccess.transformAnnotations(transformer, data)
         val explicitReceiver = callableReferenceAccess.explicitReceiver
-        val transformedLHS = when (explicitReceiver) {
+        val transformedLHS = explicitReceiver
-            is FirPropertyAccessExpression ->
+            ?.transformAsExplicitReceiver(ResolutionMode.ReceiverResolution.ForCallableReference, false)
-                transformQualifiedAccessExpression(
+            .apply {
-                    explicitReceiver, ResolutionMode.ReceiverResolution.ForCallableReference, isUsedAsReceiver = true, isUsedAsGetClassReceiver = false
+                if (this is FirResolvedQualifier && callableReferenceAccess.hasQuestionMarkAtLHS) {
-                )
+                    replaceIsNullableLHSForCallableReference(true)
-            else ->
+                }
-                explicitReceiver?.transformSingle(this, ResolutionMode.ReceiverResolution.ForCallableReference)
-        }.apply {
-            if (this is FirResolvedQualifier && callableReferenceAccess.hasQuestionMarkAtLHS) {
-                replaceIsNullableLHSForCallableReference(true)
             }
-        }
 
         transformedLHS?.let { callableReferenceAccess.replaceExplicitReceiver(transformedLHS) }
 
@@ -1142,13 +1147,7 @@ open class FirExpressionsResolveTransformer(transformer: FirAbstractBodyResolveT
 
         val transformedGetClassCall = run {
             val argument = getClassCall.argument
-            val replacedArgument: FirExpression =
+            val replacedArgument: FirExpression = argument.transformAsExplicitReceiver(dataForLhs, isUsedAsGetClassReceiver = true)
-                if (argument is FirPropertyAccessExpression)
-                    transformQualifiedAccessExpression(
-                        argument, dataForLhs, isUsedAsReceiver = true, isUsedAsGetClassReceiver = true
-                    )
-                else
-                    argument.transform(this, dataForLhs)
 
             getClassCall.argumentList.transformArguments(object : FirTransformer<Nothing?>() {
                 @Suppress("UNCHECKED_CAST")