FIR tower resolve: add level with implicit extension receiver

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/CallResolver.kt

@@ -245,7 +245,8 @@ private fun ConeCallableSymbol.hasExtensionReceiver(): Boolean = (this as? FirCa
 // (if explicit receiver exists, it always *should* be an extension receiver)
 class ScopeTowerLevel(
     session: FirSession,
-    val scope: FirScope
+    val scope: FirScope,
+    val implicitExtensionReceiver: ReceiverValue? = null
 ) : SessionBasedTowerLevel(session) {
     override fun <T : ConeSymbol> processElementsByName(
         token: TowerScopeLevel.Token<T>,
@@ -253,18 +254,21 @@ class ScopeTowerLevel(
         explicitReceiver: ExpressionReceiverValue?,
         processor: TowerScopeLevel.TowerScopeLevelProcessor<T>
     ): ProcessorAction {
+        if (explicitReceiver != null && implicitExtensionReceiver != null) {
+            return ProcessorAction.NEXT
+        }
+        val extensionReceiver = explicitReceiver ?: implicitExtensionReceiver
         return when (token) {
 
             TowerScopeLevel.Token.Properties -> scope.processPropertiesByName(name) { candidate ->
-                if (candidate.hasConsistentExtensionReceiver(explicitReceiver) && candidate.dispatchReceiverValue() == null) {
+                if (candidate.hasConsistentExtensionReceiver(extensionReceiver) && candidate.dispatchReceiverValue() == null) {
                     processor.consumeCandidate(candidate as T, dispatchReceiverValue = null)
                 } else {
                     ProcessorAction.NEXT
                 }
             }
             TowerScopeLevel.Token.Functions -> scope.processFunctionsByName(name) { candidate ->
-                // TODO: fix implicit receiver
-                if (candidate.hasConsistentExtensionReceiver(explicitReceiver) && candidate.dispatchReceiverValue() == null) {
+                if (candidate.hasConsistentExtensionReceiver(extensionReceiver) && candidate.dispatchReceiverValue() == null) {
                     processor.consumeCandidate(candidate as T, dispatchReceiverValue = null)
                 } else {
                     ProcessorAction.NEXT
@@ -606,6 +610,14 @@ class CallResolver(val typeCalculator: ReturnTypeCalculator, val components: Inf
             collector, group++
         )
 
+        for (scope in scopes!!) {
+            towerDataConsumer.consume(
+                TowerDataKind.TOWER_LEVEL,
+                ScopeTowerLevel(session, scope, implicitReceiverValue),
+                collector, group++
+            )
+        }
+
         return group
     }
 

compiler/fir/resolve/testData/resolve/extension.txt

@@ -2,5 +2,5 @@ FILE: extension.kt
     public final fun R|kotlin/String|.foo(): R|kotlin/Unit| {
     }
     public final fun R|kotlin/String|.bar(): R|kotlin/Unit| {
-        <Unresolved name: foo>#()
+        R|/foo|()
     }

compiler/fir/resolve/testData/resolve/stdlib/arrayFirstOrNull.txt

@@ -9,7 +9,7 @@ FILE: arrayFirstOrNull.kt
     }
     public final fun <T> R|kotlin/Array<out T>|.firstOrNullX(): R|T|? {
         ^firstOrNullX when () {
-            <Unresolved name: isEmpty>#() ->  {
+            <Ambiguity: isEmpty, [kotlin/collections/isEmpty, kotlin/collections/isEmpty, kotlin/collections/isEmpty, kotlin/collections/isEmpty, kotlin/collections/isEmpty, kotlin/collections/isEmpty, kotlin/collections/isEmpty, kotlin/collections/isEmpty, kotlin/collections/isEmpty, kotlin/text/isEmpty]>#() ->  {
                 Null(null)
             }
             else ->  {

compiler/fir/resolve/testData/resolve/stdlib/topLevelResolve.txt

@@ -36,7 +36,7 @@ FILE: topLevelResolve.kt
         }
         )
         lval viaWith: R|kotlin/Nothing| = R|kotlin/with|<R|kotlin/collections/List<kotlin/Int>|, R|kotlin/Nothing|>(R|kotlin/collections/listOf|<R|kotlin/Int|>(Int(42)), <L> = with@fun R|kotlin/collections/List<kotlin/Int>|.<anonymous>(it: R|kotlin/collections/List<kotlin/Int>|): R|kotlin/Function2<kotlin/collections/List<kotlin/Int>, kotlin/collections/List<kotlin/Int>, kotlin/Nothing>| {
-            <Unresolved name: map>#(<L> = map@fun <implicit>.<anonymous>(): <implicit> {
+            <Ambiguity: map, [kotlin/map, kotlin/collections/map, kotlin/collections/map, kotlin/collections/map, kotlin/collections/map, kotlin/collections/map, kotlin/collections/map, kotlin/collections/map, kotlin/collections/map, kotlin/collections/map, kotlin/collections/map, kotlin/collections/map, kotlin/collections/map, kotlin/collections/map, kotlin/collections/map, kotlin/collections/map, kotlin/sequences/map, kotlin/text/map]>#(<L> = map@fun <implicit>.<anonymous>(): <implicit> {
                 it#.times#(it#)
             }
             )
@@ -49,7 +49,7 @@ FILE: topLevelResolve.kt
         }
         )
         lval indices: R|kotlin/Nothing| = R|kotlin/with|<R|kotlin/String|, R|kotlin/Nothing|>(String(), <L> = with@fun R|kotlin/String|.<anonymous>(it: R|kotlin/String|): R|kotlin/Function2<kotlin/String, kotlin/String, kotlin/Nothing>| {
-            <Unresolved name: indices>#
+            <Ambiguity: indices, [kotlin/collections/indices, kotlin/collections/indices, kotlin/collections/indices, kotlin/collections/indices, kotlin/collections/indices, kotlin/collections/indices, kotlin/collections/indices, kotlin/collections/indices, kotlin/collections/indices, kotlin/collections/indices, kotlin/collections/indices, kotlin/collections/indices, kotlin/collections/indices, kotlin/collections/indices, kotlin/text/indices]>#
         }
         )
         lval indicesNoWith: R|kotlin/ranges/IntRange| = String().R|kotlin/text/indices|