[NI] Support assigning single array elements in named form to varargs

compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/components/AdditionalDiagnosticReporter.kt

@@ -16,6 +16,7 @@
 
 package org.jetbrains.kotlin.resolve.calls.components
 
+import org.jetbrains.kotlin.config.LanguageVersionSettings
 import org.jetbrains.kotlin.descriptors.CallableDescriptor
 import org.jetbrains.kotlin.descriptors.ReceiverParameterDescriptor
 import org.jetbrains.kotlin.resolve.calls.model.*
@@ -25,7 +26,7 @@ import org.jetbrains.kotlin.types.checker.KotlinTypeChecker
 // very initial state of component
 // todo: handle all diagnostic inside DiagnosticReporterByTrackingStrategy
 // move it to frontend module
-class AdditionalDiagnosticReporter {
+class AdditionalDiagnosticReporter(private val languageVersionSettings: LanguageVersionSettings) {
 
     fun reportAdditionalDiagnostics(
             candidate: ResolvedCallAtom,
@@ -79,7 +80,8 @@ class AdditionalDiagnosticReporter {
 
         for (parameter in resultingDescriptor.valueParameters) {
             for (argument in candidate.argumentMappingByOriginal[parameter.original]?.arguments ?: continue) {
-                val smartCastDiagnostic = createSmartCastDiagnostic(candidate, argument, argument.getExpectedType(parameter)) ?: continue
+                val effectiveExpectedType = argument.getExpectedType(parameter, languageVersionSettings)
+                val smartCastDiagnostic = createSmartCastDiagnostic(candidate, argument, effectiveExpectedType) ?: continue
 
                 val thereIsUnstableSmartCastError = candidate.diagnostics.filterIsInstance<UnstableSmartCast>().any {
                     it.argument == argument

compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/components/ArgumentsUtils.kt

@@ -16,9 +16,15 @@
 
 package org.jetbrains.kotlin.resolve.calls.components
 
+import org.jetbrains.kotlin.builtins.KotlinBuiltIns
+import org.jetbrains.kotlin.config.LanguageFeature
+import org.jetbrains.kotlin.config.LanguageVersionSettings
 import org.jetbrains.kotlin.descriptors.ParameterDescriptor
 import org.jetbrains.kotlin.descriptors.ValueParameterDescriptor
+import org.jetbrains.kotlin.resolve.calls.model.CollectionLiteralKotlinCallArgument
 import org.jetbrains.kotlin.resolve.calls.model.KotlinCallArgument
+import org.jetbrains.kotlin.resolve.calls.model.SimpleKotlinCallArgument
+import org.jetbrains.kotlin.resolve.descriptorUtil.isParameterOfAnnotation
 import org.jetbrains.kotlin.resolve.scopes.receivers.ReceiverValueWithSmartCastInfo
 import org.jetbrains.kotlin.types.UnwrappedType
 import org.jetbrains.kotlin.types.checker.intersectWrappedTypes
@@ -42,8 +48,8 @@ internal val ReceiverValueWithSmartCastInfo.stableType: UnwrappedType
         return intersectWrappedTypes(possibleTypes + receiverValue.type)
     }
 
-internal fun KotlinCallArgument.getExpectedType(parameter: ParameterDescriptor) =
-        if (this.isSpread) {
+internal fun KotlinCallArgument.getExpectedType(parameter: ParameterDescriptor, languageVersionSettings: LanguageVersionSettings) =
+        if (this.isSpread || this.isArrayAssignedAsNamedArgumentInAnnotation(parameter, languageVersionSettings)) {
             parameter.type.unwrap()
         }
         else {
@@ -51,3 +57,23 @@ internal fun KotlinCallArgument.getExpectedType(parameter: ParameterDescriptor)
         }
 
 val ValueParameterDescriptor.isVararg: Boolean get() = varargElementType != null
+val ParameterDescriptor.isVararg: Boolean get() = this.safeAs<ValueParameterDescriptor>()?.isVararg ?: false
+
+private fun KotlinCallArgument.isArrayAssignedAsNamedArgumentInAnnotation(
+        parameter: ParameterDescriptor,
+        languageVersionSettings: LanguageVersionSettings
+): Boolean {
+    if (!languageVersionSettings.supportsFeature(LanguageFeature.AssigningArraysToVarargsInNamedFormInAnnotations)) return false
+
+    if (this.argumentName == null || !parameter.isVararg) return false
+
+    return isParameterOfAnnotation(parameter) && this.isArrayOrArrayLiteral()
+}
+
+private fun KotlinCallArgument.isArrayOrArrayLiteral(): Boolean {
+    if (this is CollectionLiteralKotlinCallArgument) return true
+    if (this !is SimpleKotlinCallArgument) return false
+
+    val type = this.receiver.receiverValue.type
+    return KotlinBuiltIns.isArrayOrPrimitiveArray(type)
+}

compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/components/ResolutionParts.kt

@@ -225,7 +225,7 @@ private fun KotlinResolutionCandidate.resolveKotlinArgument(
         isReceiver: Boolean
 ) {
     val expectedType = candidateParameter?.let {
-        resolvedCall.substitutor.substituteKeepAnnotations(argument.getExpectedType(candidateParameter))
+        resolvedCall.substitutor.substituteKeepAnnotations(argument.getExpectedType(candidateParameter, callComponents.languageVersionSettings))
     }
     addResolvedKtPrimitive(resolveKtPrimitive(csBuilder, argument, expectedType, this, isReceiver))
 }

compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/model/KotlinResolverContext.kt

@@ -18,6 +18,7 @@ package org.jetbrains.kotlin.resolve.calls.model
 
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns
 import org.jetbrains.kotlin.builtins.ReflectionTypes
+import org.jetbrains.kotlin.config.LanguageVersionSettings
 import org.jetbrains.kotlin.descriptors.CallableDescriptor
 import org.jetbrains.kotlin.descriptors.FunctionDescriptor
 import org.jetbrains.kotlin.resolve.calls.components.*
@@ -40,7 +41,8 @@ class KotlinCallComponents(
         val typeArgumentsToParametersMapper: TypeArgumentsToParametersMapper,
         val constraintInjector: ConstraintInjector,
         val reflectionTypes: ReflectionTypes,
-        val builtIns: KotlinBuiltIns
+        val builtIns: KotlinBuiltIns,
+        val languageVersionSettings: LanguageVersionSettings
 )
 
 class SimpleCandidateFactory(