From 7872b2191421bc413b749d722871b37cfdc23a8d Mon Sep 17 00:00:00 2001
From: Jinseong Jeon <jsjeon@google.com>
Date: Tue, 21 Jul 2020 15:36:23 -0700
Subject: [PATCH] FIR: handle object invoke via type alias

---
 .../calls/tower/FirTowerResolverSession.kt    | 24 ++++++++++++-------
 .../box/typealias/typeAliasObjectCallable.kt  |  1 -
 .../typeAliasObjectWithInvoke.fir.kt          |  4 ++--
 3 files changed, 17 insertions(+), 12 deletions(-)

diff --git a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/tower/FirTowerResolverSession.kt b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/tower/FirTowerResolverSession.kt
index 592578c6b17..dae78e01fe9 100644
--- a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/tower/FirTowerResolverSession.kt
+++ b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/tower/FirTowerResolverSession.kt
@@ -7,17 +7,15 @@ package org.jetbrains.kotlin.fir.resolve.calls.tower
 
 import org.jetbrains.kotlin.fir.FirSession
 import org.jetbrains.kotlin.fir.asReversedFrozen
+import org.jetbrains.kotlin.fir.declarations.FirRegularClass
 import org.jetbrains.kotlin.fir.declarations.isInner
 import org.jetbrains.kotlin.fir.expressions.FirExpression
 import org.jetbrains.kotlin.fir.expressions.FirQualifiedAccessExpression
 import org.jetbrains.kotlin.fir.expressions.FirResolvedQualifier
 import org.jetbrains.kotlin.fir.expressions.builder.FirQualifiedAccessExpressionBuilder
 import org.jetbrains.kotlin.fir.references.FirSuperReference
-import org.jetbrains.kotlin.fir.resolve.BodyResolveComponents
-import org.jetbrains.kotlin.fir.resolve.buildResolvedQualifierForClass
+import org.jetbrains.kotlin.fir.resolve.*
 import org.jetbrains.kotlin.fir.resolve.calls.*
-import org.jetbrains.kotlin.fir.resolve.scope
-import org.jetbrains.kotlin.fir.resolve.transformQualifiedAccessUsingSmartcastInfo
 import org.jetbrains.kotlin.fir.resolve.transformers.body.resolve.firUnsafe
 import org.jetbrains.kotlin.fir.scopes.FirCompositeScope
 import org.jetbrains.kotlin.fir.scopes.FirScope
@@ -26,6 +24,7 @@ import org.jetbrains.kotlin.fir.scopes.unsubstitutedScope
 import org.jetbrains.kotlin.fir.symbols.impl.FirCallableSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirClassSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirRegularClassSymbol
+import org.jetbrains.kotlin.fir.symbols.impl.FirTypeAliasSymbol
 import org.jetbrains.kotlin.fir.types.*
 import org.jetbrains.kotlin.fir.types.impl.FirImplicitBuiltinTypeRef
 import org.jetbrains.kotlin.resolve.calls.tasks.ExplicitReceiverKind
@@ -563,11 +562,13 @@ class FirTowerResolverSession internal constructor(
         val invokeBuiltinExtensionMode = invokeResolveMode == InvokeResolveMode.RECEIVER_FOR_INVOKE_BUILTIN_EXTENSION
 
         for (invokeReceiverCandidate in candidateFactoriesAndCollectors.invokeReceiverCollector!!.bestCandidates()) {
-            val symbol = invokeReceiverCandidate.symbol
-            if (symbol !is FirCallableSymbol<*> && symbol !is FirRegularClassSymbol) continue
-
-            val isExtensionFunctionType =
-                (symbol as? FirCallableSymbol<*>)?.fir?.returnTypeRef?.isExtensionFunctionType(components.session) == true
+            val returnTypeRef = when (val symbol = invokeReceiverCandidate.symbol) {
+                is FirTypeAliasSymbol -> symbol.fir.expandedTypeRef
+                is FirCallableSymbol<*> -> symbol.fir.returnTypeRef
+                is FirRegularClassSymbol -> null
+                else -> continue
+            }
+            val isExtensionFunctionType = returnTypeRef?.isExtensionFunctionType(components.session) == true
 
             if (invokeBuiltinExtensionMode && !isExtensionFunctionType) {
                 continue
@@ -653,6 +654,11 @@ private fun BodyResolveComponents.createExplicitReceiverForInvoke(
             candidate, info, invokeBuiltinExtensionMode, extensionReceiverExpression, symbol
         )
         is FirRegularClassSymbol -> buildResolvedQualifierForClass(symbol, sourceElement = null)
+        is FirTypeAliasSymbol -> {
+            val type = symbol.fir.expandedTypeRef.coneTypeUnsafe<ConeClassLikeType>().fullyExpandedType(session)
+            val expansionRegularClass = type.lookupTag.toSymbol(session)?.fir as? FirRegularClass
+            buildResolvedQualifierForClass(expansionRegularClass!!.symbol, sourceElement = symbol.fir.source)
+        }
         else -> throw AssertionError()
     }
 }
diff --git a/compiler/testData/codegen/box/typealias/typeAliasObjectCallable.kt b/compiler/testData/codegen/box/typealias/typeAliasObjectCallable.kt
index 0f3d325b5b5..5a321ecd586 100644
--- a/compiler/testData/codegen/box/typealias/typeAliasObjectCallable.kt
+++ b/compiler/testData/codegen/box/typealias/typeAliasObjectCallable.kt
@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 object O {
     val x = "OK"
 
diff --git a/compiler/testData/diagnostics/tests/typealias/typeAliasObjectWithInvoke.fir.kt b/compiler/testData/diagnostics/tests/typealias/typeAliasObjectWithInvoke.fir.kt
index 958b5f28c16..7f0db227d54 100644
--- a/compiler/testData/diagnostics/tests/typealias/typeAliasObjectWithInvoke.fir.kt
+++ b/compiler/testData/diagnostics/tests/typealias/typeAliasObjectWithInvoke.fir.kt
@@ -15,10 +15,10 @@ typealias WI = ObjectWithInvoke
 
 typealias CWI = ClassWithCompanionObjectWithInvoke
 
-val test1 = <!INAPPLICABLE_CANDIDATE!>WI<!>()
+val test1 = WI()
 val test2 = <!INAPPLICABLE_CANDIDATE!>WI<!>(null)
 
 val test3 = CWI()
-val test4 = <!INAPPLICABLE_CANDIDATE!>CWI<!>("")
+val test4 = CWI("")
 val test5 = <!INAPPLICABLE_CANDIDATE!>CWI<!>(null)
 val test5a = <!INAPPLICABLE_CANDIDATE!>ClassWithCompanionObjectWithInvoke<!>(null)