[FIR] Introduce FirResolvable

FirResolvable is an interface representates fir node wit calleeReference
It will be useful for infer `try` and `when` expressions as function call

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

@@ -7,9 +7,8 @@ package org.jetbrains.kotlin.fir.resolve
 
 import org.jetbrains.kotlin.descriptors.ClassKind
 import org.jetbrains.kotlin.fir.*
-import org.jetbrains.kotlin.fir.FirSession
-import org.jetbrains.kotlin.fir.componentArrayAccessor
 import org.jetbrains.kotlin.fir.declarations.*
+import org.jetbrains.kotlin.fir.expressions.FirResolvable
 import org.jetbrains.kotlin.fir.expressions.FirQualifiedAccess
 import org.jetbrains.kotlin.fir.expressions.FirResolvedQualifier
 import org.jetbrains.kotlin.fir.references.FirErrorNamedReference
@@ -256,10 +255,12 @@ fun BodyResolveComponents.typeForQualifier(resolvedQualifier: FirResolvedQualifi
     )
 }
 
-
-fun <T : FirQualifiedAccess> BodyResolveComponents.typeFromCallee(access: T): FirResolvedTypeRef {
+fun <T : FirResolvable> BodyResolveComponents.typeFromCallee(access: T): FirResolvedTypeRef {
     val makeNullable: Boolean by lazy {
-        access.safe && access.explicitReceiver!!.resultType.coneTypeUnsafe<ConeKotlinType>().isNullable
+        if (access is FirQualifiedAccess)
+            access.safe && access.explicitReceiver!!.resultType.coneTypeUnsafe<ConeKotlinType>().isNullable
+        else
+            false
     }
 
     return when (val newCallee = access.calleeReference) {

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

@@ -9,7 +9,7 @@ import org.jetbrains.kotlin.fir.FirSession
 import org.jetbrains.kotlin.fir.declarations.FirAnonymousFunction
 import org.jetbrains.kotlin.fir.declarations.FirValueParameter
 import org.jetbrains.kotlin.fir.expressions.*
-import org.jetbrains.kotlin.fir.render
+import org.jetbrains.kotlin.fir.resolve.inference.returnExpressions
 import org.jetbrains.kotlin.fir.resolve.transformers.firUnsafe
 import org.jetbrains.kotlin.fir.resolve.withNullability
 import org.jetbrains.kotlin.fir.types.*
@@ -71,14 +71,14 @@ fun resolveArgumentExpression(
 
 fun resolveSubCallArgument(
     csBuilder: ConstraintSystemBuilder,
-    argument: FirFunctionCall,
+    argument: FirResolvable,
     expectedType: ConeKotlinType,
     sink: CheckerSink,
     isReceiver: Boolean,
     isSafeCall: Boolean,
     typeProvider: (FirExpression) -> FirTypeRef?
 ) {
-    val candidate = argument.candidate() ?: return resolvePlainExpressionArgument(csBuilder, argument, expectedType, sink, isReceiver, isSafeCall, typeProvider)
+    val candidate = argument.candidate() ?: return resolvePlainExpressionArgument(csBuilder, argument as FirExpression, expectedType, sink, isReceiver, isSafeCall, typeProvider)
     val type = sink.components.returnTypeCalculator.tryCalculateReturnType(candidate.symbol.firUnsafe()).coneTypeUnsafe<ConeKotlinType>()
     val argumentType = candidate.substitutor.substituteOrSelf(type)
     resolvePlainArgumentType(csBuilder, argumentType, expectedType, sink, isReceiver, isSafeCall)

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

@@ -7,7 +7,6 @@ package org.jetbrains.kotlin.fir.resolve.calls
 
 import org.jetbrains.kotlin.fir.expressions.*
 import org.jetbrains.kotlin.fir.symbols.AbstractFirBasedSymbol
-import org.jetbrains.kotlin.fir.symbols.FirBasedSymbol
 import org.jetbrains.kotlin.resolve.calls.components.PostponedArgumentsAnalyzer
 import org.jetbrains.kotlin.resolve.calls.inference.model.ConstraintStorage
 import org.jetbrains.kotlin.resolve.calls.tasks.ExplicitReceiverKind
@@ -48,7 +47,7 @@ fun PostponedArgumentsAnalyzer.Context.addSubsystemFromExpression(expression: Fi
     }
 }
 
-internal fun FirQualifiedAccess.candidate(): Candidate? {
+internal fun FirResolvable.candidate(): Candidate? {
     return when (val callee = this.calleeReference) {
         is FirNamedReferenceWithCandidate -> return callee.candidate
         else -> null

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/inference/FirCallCompleter.kt

@@ -8,8 +8,9 @@ package org.jetbrains.kotlin.fir.resolve.inference
 import org.jetbrains.kotlin.fir.copy
 import org.jetbrains.kotlin.fir.declarations.FirAnonymousFunction
 import org.jetbrains.kotlin.fir.declarations.impl.FirValueParameterImpl
+import org.jetbrains.kotlin.fir.expressions.FirBlock
+import org.jetbrains.kotlin.fir.expressions.FirResolvable
 import org.jetbrains.kotlin.fir.expressions.FirExpression
-import org.jetbrains.kotlin.fir.expressions.FirQualifiedAccess
 import org.jetbrains.kotlin.fir.resolve.BodyResolveComponents
 import org.jetbrains.kotlin.fir.resolve.calls.*
 import org.jetbrains.kotlin.fir.resolve.substitution.ConeSubstitutor
@@ -35,7 +36,7 @@ class FirCallCompleter(
     private val transformer: FirBodyResolveTransformer,
     private val inferenceComponents: InferenceComponents
 ) : BodyResolveComponents by transformer {
-    fun <T : FirQualifiedAccess> completeCall(call: T, expectedTypeRef: FirTypeRef?): T {
+    fun <T : FirResolvable> completeCall(call: T, expectedTypeRef: FirTypeRef?): T {
         val typeRef = typeFromCallee(call)
         if (typeRef.type is ConeKotlinErrorType) {
             if (call is FirExpression) {
@@ -48,6 +49,10 @@ class FirCallCompleter(
 
         val initialType = initialSubstitutor.substituteOrSelf(typeRef.type)
 
+        if (call is FirExpression) {
+            call.resultType = typeRef.resolvedTypeFromPrototype(initialType)
+        }
+
         if (expectedTypeRef is FirResolvedTypeRef) {
             candidate.system.addSubtypeConstraint(initialType, expectedTypeRef.type, SimpleConstraintSystemConstraintPosition)
         }

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

@@ -5,13 +5,10 @@
 
 package org.jetbrains.kotlin.fir.expressions
 
-import org.jetbrains.kotlin.fir.FirReference
 import org.jetbrains.kotlin.fir.visitors.FirTransformer
 import org.jetbrains.kotlin.fir.visitors.FirVisitor
 
-interface FirQualifiedAccess : FirStatement {
-    val calleeReference: FirReference
-
+interface FirQualifiedAccess : FirResolvable {
     val safe: Boolean get() = false
 
     val explicitReceiver: FirExpression? get() = null

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

@@ -0,0 +1,12 @@
+/*
+ * Copyright 2010-2019 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.fir.expressions
+
+import org.jetbrains.kotlin.fir.FirReference
+
+interface FirResolvable : FirStatement {
+    val calleeReference: FirReference
+}