Replace resolution error for suspend-conversion with call checker error

compiler/frontend/src/org/jetbrains/kotlin/resolve/PlatformConfiguratorBase.kt

@@ -49,7 +49,7 @@ private val DEFAULT_CALL_CHECKERS = listOf(
     PrimitiveNumericComparisonCallChecker, LambdaWithSuspendModifierCallChecker,
     UselessElvisCallChecker(), ResultTypeWithNullableOperatorsChecker(), NullableVarargArgumentCallChecker,
     NamedFunAsExpressionChecker, ContractNotAllowedCallChecker, ReifiedTypeParameterSubstitutionChecker(),
-    MissingDependencySupertypeChecker.ForCalls, AbstractClassInstantiationChecker,
+    MissingDependencySupertypeChecker.ForCalls, AbstractClassInstantiationChecker, SuspendConversionCallChecker
 )
 private val DEFAULT_TYPE_CHECKERS = emptyList<AdditionalTypeChecker>()
 private val DEFAULT_CLASSIFIER_USAGE_CHECKERS = listOf(

compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/checkers/SuspendConversionCallChecker.kt

@@ -0,0 +1,59 @@
+/*
+ * Copyright 2010-2020 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.resolve.calls.checkers
+
+import com.intellij.psi.PsiElement
+import org.jetbrains.kotlin.builtins.isSuspendFunctionType
+import org.jetbrains.kotlin.config.LanguageFeature
+import org.jetbrains.kotlin.descriptors.FunctionDescriptor
+import org.jetbrains.kotlin.diagnostics.Errors
+import org.jetbrains.kotlin.psi.KtCallableReferenceExpression
+import org.jetbrains.kotlin.resolve.calls.callUtil.getResolvedCall
+import org.jetbrains.kotlin.resolve.calls.model.CallableReferenceKotlinCallArgument
+import org.jetbrains.kotlin.resolve.calls.model.ResolvedCall
+import org.jetbrains.kotlin.resolve.calls.model.ResolvedCallArgument
+import org.jetbrains.kotlin.resolve.calls.tower.NewResolvedCallImpl
+import org.jetbrains.kotlin.resolve.calls.tower.psiCallArgument
+import org.jetbrains.kotlin.resolve.calls.tower.psiExpression
+
+object SuspendConversionCallChecker : CallChecker {
+    override fun check(resolvedCall: ResolvedCall<*>, reportOn: PsiElement, context: CallCheckerContext) {
+        if (resolvedCall !is NewResolvedCallImpl<*>) return
+
+        if (context.languageVersionSettings.supportsFeature(LanguageFeature.SuspendConversion)) return
+
+        val argumentsWithSuspendConversion = resolvedCall.resolvedCallAtom.argumentsWithSuspendConversion
+
+        for (argumentWithSuspendConversion in argumentsWithSuspendConversion.keys) {
+            context.trace.report(
+                Errors.UNSUPPORTED_FEATURE.on(
+                    argumentWithSuspendConversion.psiCallArgument.valueArgument.asElement(),
+                    LanguageFeature.SuspendConversion to context.languageVersionSettings
+                )
+            )
+        }
+
+        for ((parameter, argument) in resolvedCall.argumentMappingByOriginal) {
+            if (!parameter.type.isSuspendFunctionType) continue
+            if (argument !is ResolvedCallArgument.SimpleArgument) continue
+
+            val callArgument = argument.callArgument
+            if (callArgument !is CallableReferenceKotlinCallArgument) continue
+
+            val callableReferenceExpression = callArgument.psiExpression as? KtCallableReferenceExpression ?: continue
+            val argumentCall = callableReferenceExpression.callableReference.getResolvedCall(context.trace.bindingContext) ?: continue
+            val target = argumentCall.resultingDescriptor as? FunctionDescriptor ?: continue
+            if (!target.isSuspend) {
+                context.trace.report(
+                    Errors.UNSUPPORTED_FEATURE.on(
+                        callableReferenceExpression,
+                        LanguageFeature.SuspendConversion to context.languageVersionSettings
+                    )
+                )
+            }
+        }
+    }
+}