[NI] Report warning if candidate was chosen using only @OverloadResolutionByLambdaReturnType

compiler/frontend/src/org/jetbrains/kotlin/diagnostics/Errors.java

@@ -759,6 +759,8 @@ public interface Errors {
     DiagnosticFactory1<PsiElement, TypeParameterDescriptor> TYPE_PARAMETER_AS_REIFIED_ARRAY_WARNING = DiagnosticFactory1.create(WARNING);
     DiagnosticFactory1<PsiElement, KotlinType> REIFIED_TYPE_FORBIDDEN_SUBSTITUTION = DiagnosticFactory1.create(ERROR);
     DiagnosticFactory1<PsiElement, KotlinType> REIFIED_TYPE_UNSAFE_SUBSTITUTION = DiagnosticFactory1.create(WARNING);
+    DiagnosticFactory0<KtElement> CANDIDATE_CHOSEN_USING_OVERLOAD_RESOLUTION_BY_LAMBDA_ANNOTATION = DiagnosticFactory0.create(WARNING);
+
 
     DiagnosticFactory3<KtReferenceExpression, ClassifierDescriptor, WrongResolutionToClassifier, String> RESOLUTION_TO_CLASSIFIER =
             DiagnosticFactory3.create(ERROR);

compiler/frontend/src/org/jetbrains/kotlin/diagnostics/rendering/DefaultErrorMessages.java

@@ -896,6 +896,7 @@ public class DefaultErrorMessages {
         MAP.put(REIFIED_TYPE_FORBIDDEN_SUBSTITUTION, "Cannot use ''{0}'' as reified type parameter", RENDER_TYPE);
         MAP.put(REIFIED_TYPE_UNSAFE_SUBSTITUTION, "It may be not safe to use ''{0}'' as an argument for a reified type parameter. Use a non-generic type or * if possible", RENDER_TYPE);
         MAP.put(TYPE_PARAMETERS_NOT_ALLOWED, "Type parameters are not allowed here");
+        MAP.put(CANDIDATE_CHOSEN_USING_OVERLOAD_RESOLUTION_BY_LAMBDA_ANNOTATION, "Candidate was choosen only by @OverloadResolutionByLambdaReturnType annotation");
 
         MAP.put(TYPE_PARAMETER_OF_PROPERTY_NOT_USED_IN_RECEIVER, "Type parameter of a property must be used in its receiver type");
 

compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/DiagnosticReporterByTrackingStrategy.kt

@@ -77,6 +77,9 @@ class DiagnosticReporterByTrackingStrategy(
                     trace.report(factory.on(it, typeVariable.originalTypeParameter))
                 }
             }
+            CandidateChosenUsingOverloadResolutionByLambdaAnnotation::class.java -> {
+                trace.report(CANDIDATE_CHOSEN_USING_OVERLOAD_RESOLUTION_BY_LAMBDA_ANNOTATION.on(psiKotlinCall.psiCall.callElement))
+            }
         }
     }
 

compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/KotlinCallResolver.kt

@@ -155,6 +155,7 @@ class KotlinCallResolver(
 
                 if (maximallySpecificCandidates.size > 1) {
                     maximallySpecificCandidates = candidates.toMutableSet().apply { removeAll(candidatesWithAnnotation) }
+                    maximallySpecificCandidates.singleOrNull()?.addDiagnostic(CandidateChosenUsingOverloadResolutionByLambdaAnnotation())
                 }
             }
         }

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

@@ -243,3 +243,9 @@ class NotEnoughInformationForLambdaParameter(
         reporter.onCallArgument(lambdaArgument, this)
     }
 }
+
+class CandidateChosenUsingOverloadResolutionByLambdaAnnotation : KotlinCallDiagnostic(RESOLVED) {
+    override fun report(reporter: DiagnosticReporter) {
+        reporter.onCall(this)
+    }
+}

compiler/testData/codegen/box/ranges/unsigned/literal/simpleRange.kt

@@ -1,3 +1,4 @@
+// IGNORE_BACKEND_FIR: JVM_IR
 // KJS_WITH_FULL_RUNTIME
 // Auto-generated by org.jetbrains.kotlin.generators.tests.GenerateRangesCodegenTestData. DO NOT EDIT!
 // WITH_RUNTIME

compiler/testData/diagnostics/testsWithStdLib/factoryPattern/overloadByLambdaReturnType_enabled.fir.kt

@@ -45,4 +45,17 @@ fun test_4() {
 fun test_5() {
     val x = <!AMBIGUITY!>create<!>("") { 1 }
     takeInt(x)
-}
+}
+
+interface A
+interface B
+interface C : A, B
+
+@OverloadResolutionByLambdaReturnType
+fun foo(f: () -> A): Int = 1
+fun foo(f: () -> B): String = ""
+
+fun test_6(c: C) {
+    val x = <!AMBIGUITY!>foo<!> { c }
+    takeString(x)
+}

compiler/testData/diagnostics/testsWithStdLib/factoryPattern/overloadByLambdaReturnType_enabled.kt

@@ -30,7 +30,7 @@ fun test_2() {
 }
 
 fun test_3() {
-    val x = create <!TYPE_MISMATCH!>{ <!CONSTANT_EXPECTED_TYPE_MISMATCH!>1.0<!> }<!>
+    val x = <!CANDIDATE_CHOSEN_USING_OVERLOAD_RESOLUTION_BY_LAMBDA_ANNOTATION!>create <!TYPE_MISMATCH!>{ <!CONSTANT_EXPECTED_TYPE_MISMATCH!>1.0<!> }<!><!>
 }
 
 @OverloadResolutionByLambdaReturnType
@@ -45,4 +45,17 @@ fun test_4() {
 fun test_5() {
     val x = create("") { 1 }
     takeInt(x)
-}
+}
+
+interface A
+interface B
+interface C : A, B
+
+@OverloadResolutionByLambdaReturnType
+fun foo(f: () -> A): Int = 1
+fun foo(f: () -> B): String = ""
+
+fun test_6(c: C) {
+    val x = <!CANDIDATE_CHOSEN_USING_OVERLOAD_RESOLUTION_BY_LAMBDA_ANNOTATION!>foo { c }<!>
+    takeString(x)
+}

compiler/testData/diagnostics/testsWithStdLib/factoryPattern/overloadByLambdaReturnType_enabled.txt

@@ -4,6 +4,8 @@ package
 public fun create(/*0*/ f: (kotlin.Int) -> kotlin.String): kotlin.String
 @kotlin.OverloadResolutionByLambdaReturnType public fun </*0*/ K> create(/*0*/ x: K, /*1*/ f: (K) -> kotlin.Int): kotlin.Int
 public fun </*0*/ T> create(/*0*/ x: T, /*1*/ f: (T) -> kotlin.String): kotlin.String
+@kotlin.OverloadResolutionByLambdaReturnType public fun foo(/*0*/ f: () -> A): kotlin.Int
+public fun foo(/*0*/ f: () -> B): kotlin.String
 public fun takeInt(/*0*/ s: kotlin.Int): kotlin.Unit
 public fun takeString(/*0*/ s: kotlin.String): kotlin.Unit
 public fun test_1(): kotlin.Unit
@@ -11,6 +13,25 @@ public fun test_2(): kotlin.Unit
 public fun test_3(): kotlin.Unit
 public fun test_4(): kotlin.Unit
 public fun test_5(): kotlin.Unit
+public fun test_6(/*0*/ c: C): kotlin.Unit
+
+public interface A {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface B {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface C : A, B {
+    public open override /*2*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*2*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*2*/ /*fake_override*/ fun toString(): kotlin.String
+}
 
 package kotlin {