Simplify code in callable reference resolution

compiler/frontend/src/org/jetbrains/kotlin/resolve/callableReferences/CallableReferencesResolutionUtils.kt

@@ -21,7 +21,6 @@ import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.descriptors.annotations.Annotations
 import org.jetbrains.kotlin.diagnostics.Errors.CALLABLE_REFERENCE_LHS_NOT_A_CLASS
 import org.jetbrains.kotlin.psi.KtCallableReferenceExpression
-import org.jetbrains.kotlin.psi.KtSimpleNameExpression
 import org.jetbrains.kotlin.resolve.BindingContext
 import org.jetbrains.kotlin.resolve.calls.CallResolver
 import org.jetbrains.kotlin.resolve.calls.callResolverUtil.ResolveArgumentsMode
@@ -40,37 +39,6 @@ import org.jetbrains.kotlin.types.TypeUtils
 import org.jetbrains.kotlin.types.expressions.DoubleColonLHS
 import org.jetbrains.kotlin.types.expressions.ExpressionTypingUtils
 
-private fun <D : CallableDescriptor> ResolveArgumentsMode.acceptResolution(results: OverloadResolutionResults<D>, trace: TemporaryTraceAndCache) {
-    when (this) {
-        ResolveArgumentsMode.SHAPE_FUNCTION_ARGUMENTS ->
-            if (results.isSingleResult) trace.commit()
-        ResolveArgumentsMode.RESOLVE_FUNCTION_ARGUMENTS ->
-            if (results.isSomething()) trace.commit()
-    }
-}
-
-private fun resolvePossiblyAmbiguousCallableReference(
-        reference: KtSimpleNameExpression,
-        receiver: Receiver?,
-        context: ResolutionContext<*>,
-        resolutionMode: ResolveArgumentsMode,
-        callResolver: CallResolver
-): OverloadResolutionResults<CallableDescriptor> {
-    val call = CallMaker.makeCall(reference, receiver, null, reference, emptyList())
-    val temporaryTrace = TemporaryTraceAndCache.create(context, "resolve callable reference as function", reference)
-    val newContext = if (resolutionMode == ResolveArgumentsMode.SHAPE_FUNCTION_ARGUMENTS)
-        context.replaceTraceAndCache(temporaryTrace).replaceExpectedType(TypeUtils.NO_EXPECTED_TYPE)
-    else
-        context.replaceTraceAndCache(temporaryTrace)
-    val callResolutionContext = BasicCallResolutionContext.create(
-            newContext, call, CheckArgumentTypesMode.CHECK_CALLABLE_TYPE)
-    val resolutionResults = callResolver.resolveCallForMember(reference, callResolutionContext)
-    resolutionMode.acceptResolution(resolutionResults, temporaryTrace)
-    return resolutionResults
-}
-
-private fun OverloadResolutionResults<*>.isSomething(): Boolean = !isNothing
-
 fun resolvePossiblyAmbiguousCallableReference(
         callableReferenceExpression: KtCallableReferenceExpression,
         lhs: DoubleColonLHS?,
@@ -80,15 +48,28 @@ fun resolvePossiblyAmbiguousCallableReference(
 ): OverloadResolutionResults<CallableDescriptor>? {
     val reference = callableReferenceExpression.callableReference
 
-    fun resolveWithReceiver(traceTitle: String, receiver: Receiver?): OverloadResolutionResults<CallableDescriptor> {
-        val temporaryTraceAndCache = TemporaryTraceAndCache.create(context, traceTitle, reference)
-        val newContext = context.replaceTraceAndCache(temporaryTraceAndCache)
-        val results = resolvePossiblyAmbiguousCallableReference(reference, receiver, newContext, resolutionMode, callResolver)
-        resolutionMode.acceptResolution(results, temporaryTraceAndCache)
-        return results
+    fun resolveWithReceiver(traceTitle: String?, receiver: Receiver?): OverloadResolutionResults<CallableDescriptor>? {
+        val call = CallMaker.makeCall(reference, receiver, null, reference, emptyList())
+        val temporaryTrace = TemporaryTraceAndCache.create(context, traceTitle, reference)
+        val newContext =
+                if (resolutionMode == ResolveArgumentsMode.SHAPE_FUNCTION_ARGUMENTS)
+                    context.replaceTraceAndCache(temporaryTrace).replaceExpectedType(TypeUtils.NO_EXPECTED_TYPE)
+                else
+                    context.replaceTraceAndCache(temporaryTrace)
+
+        val resolutionResults = callResolver.resolveCallForMember(
+                reference, BasicCallResolutionContext.create(newContext, call, CheckArgumentTypesMode.CHECK_CALLABLE_TYPE)
+        )
+
+        val shouldCommitTrace =
+                if (resolutionMode == ResolveArgumentsMode.SHAPE_FUNCTION_ARGUMENTS) resolutionResults.isSingleResult
+                else !resolutionResults.isNothing
+        if (shouldCommitTrace) temporaryTrace.commit()
+
+        return if (resolutionResults.isNothing) null else resolutionResults
     }
 
-    val lhsType = lhs?.type ?: return resolvePossiblyAmbiguousCallableReference(reference, null, context, resolutionMode, callResolver)
+    val lhsType = lhs?.type ?: return resolveWithReceiver("resolve callable reference with empty LHS", null)
 
     when (lhs) {
         is DoubleColonLHS.Type -> {
@@ -101,17 +82,17 @@ fun resolvePossiblyAmbiguousCallableReference(
             val qualifier = context.trace.get(BindingContext.QUALIFIER, callableReferenceExpression.receiverExpression!!)
             if (qualifier is ClassQualifier) {
                 val possibleStatic = resolveWithReceiver("resolve unbound callable reference in static scope", qualifier)
-                if (possibleStatic.isSomething()) return possibleStatic
+                if (possibleStatic != null) return possibleStatic
             }
 
             val possibleWithReceiver = resolveWithReceiver("resolve unbound callable reference with receiver", TransientReceiver(lhsType))
-            if (possibleWithReceiver.isSomething()) return possibleWithReceiver
+            if (possibleWithReceiver != null) return possibleWithReceiver
         }
         is DoubleColonLHS.Expression -> {
             val result = resolveWithReceiver("resolve bound callable reference", ExpressionReceiver.create(
                     callableReferenceExpression.receiverExpression!!, lhsType, context.trace.bindingContext
             ))
-            if (result.isSomething()) return result
+            if (result != null) return result
         }
     }
 

idea/testData/quickfix/createFromUsage/createVariable/localVariable/callableRef.kt

@@ -1,10 +1,9 @@
 // "Create local variable 'foo'" "false"
 // ACTION: Rename reference
-// ACTION: Add 'f =' to argument
 // ACTION: Create function 'foo'
 // ERROR: Unresolved reference: foo
 fun test(f: (Int) -> Int) {}
 
 fun refer() {
     val v = test(::<caret>foo)
-}
+}

idea/testData/quickfix/createFromUsage/createVariable/parameter/callableRef.kt

@@ -1,10 +1,9 @@
 // "Create parameter 'foo'" "false"
 // ACTION: Rename reference
-// ACTION: Add 'f =' to argument
 // ACTION: Create function 'foo'
 // ERROR: Unresolved reference: foo
 fun test(f: (Int) -> Int) {}
 
 fun refer() {
     val v = test(::<caret>foo)
-}
+}

idea/testData/quickfix/createFromUsage/createVariable/property/callableRef.kt

@@ -1,10 +1,9 @@
 // "Create property 'foo'" "false"
 // ACTION: Rename reference
-// ACTION: Add 'f =' to argument
 // ACTION: Create function 'foo'
 // ERROR: Unresolved reference: foo
 fun test(f: (Int) -> Int) {}
 
 fun refer() {
     val v = test(::<caret>foo)
-}
+}