[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))
+            }
         }
     }