Resolve '%' as 'mod' when LV=1.0

compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/tower/NewResolutionOldInference.kt

@@ -16,6 +16,7 @@
 
 package org.jetbrains.kotlin.resolve.calls.tower
 
+import org.jetbrains.kotlin.config.LanguageFeature
 import org.jetbrains.kotlin.config.LanguageVersionSettings
 import org.jetbrains.kotlin.descriptors.CallableDescriptor
 import org.jetbrains.kotlin.descriptors.FunctionDescriptor
@@ -155,7 +156,14 @@ class NewResolutionOldInference(
         val dynamicScope = dynamicCallableDescriptors.createDynamicDescriptorScope(context.call, context.scope.ownerDescriptor)
         val scopeTower = ImplicitScopeTowerImpl(context, dynamicScope, syntheticScopes, syntheticConstructorsProvider, context.call.createLookupLocation())
 
-        val processor = kind.createTowerProcessor(this, name, tracing, scopeTower, detailedReceiver, context)
+        val shouldUseOperatorRem = languageVersionSettings.supportsFeature(LanguageFeature.OperatorRem)
+        val isBinaryRemOperator = isBinaryRemOperator(context.call)
+        val nameToResolve = if (isBinaryRemOperator && !shouldUseOperatorRem)
+            OperatorConventions.REM_TO_MOD_OPERATION_NAMES[name]!!
+        else
+            name
+
+        val processor = kind.createTowerProcessor(this, nameToResolve, tracing, scopeTower, detailedReceiver, context)
 
         if (context.collectAllCandidates) {
             return allCandidatesResult(towerResolver.collectAllCandidates(scopeTower, processor))
@@ -168,14 +176,14 @@ class NewResolutionOldInference(
                                             candidates.all {
                                                 it.candidateStatus.resultingApplicability == ResolutionCandidateApplicability.INAPPLICABLE
                                             }
-        if (emptyOrInapplicableCandidates && isBinaryRemOperator(context.call)) {
+        if (isBinaryRemOperator && shouldUseOperatorRem && emptyOrInapplicableCandidates) {
             val deprecatedName = OperatorConventions.REM_TO_MOD_OPERATION_NAMES[name]
             val processorForDeprecatedName = kind.createTowerProcessor(this, deprecatedName!!, tracing, scopeTower, detailedReceiver, context)
             candidates = towerResolver.runResolve(scopeTower, processorForDeprecatedName, useOrder = kind != ResolutionKind.CallableReference)
         }
 
         if (candidates.isEmpty()) {
-            if (reportAdditionalDiagnosticIfNoCandidates(context, name, kind, scopeTower, detailedReceiver)) {
+            if (reportAdditionalDiagnosticIfNoCandidates(context, nameToResolve, kind, scopeTower, detailedReceiver)) {
                 return OverloadResolutionResultsImpl.nameNotFound()
             }
         }

compiler/testData/diagnostics/tests/operatorRem/resolveToModWhenNoOperatorRemFeature.kt

@@ -0,0 +1,39 @@
+// !LANGUAGE: -OperatorRem
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
+object ModAndRem {
+    operator fun mod(x: Int) = 0
+    <!UNSUPPORTED_FEATURE!>operator<!> fun rem(x: Int) = ""
+}
+
+object ModAssignAndRemAssign {
+    operator fun modAssign(x: String) {}
+    <!UNSUPPORTED_FEATURE!>operator<!> fun remAssign(x: Int) {}
+}
+
+object RemAndModAssign {
+    operator fun modAssign(x: Int) {}
+    <!UNSUPPORTED_FEATURE!>operator<!> fun rem(x: Int) = RemAndModAssign
+}
+
+object OnlyRem {
+    <!UNSUPPORTED_FEATURE!>operator<!> fun rem(x: Int) {}
+    <!UNSUPPORTED_FEATURE!>operator<!> fun remAssign(x: Int) {}
+}
+
+fun test() {
+    takeInt(ModAndRem % 1)
+
+    val c = ModAssignAndRemAssign
+    c %= ""
+
+    var c1 = RemAndModAssign
+    c1 %= 1
+
+    OnlyRem <!UNRESOLVED_REFERENCE!>%<!> 1
+
+    val c2 = OnlyRem
+    c2 <!UNRESOLVED_REFERENCE!>%=<!> 1
+}
+
+fun takeInt(x: Int) {}

compiler/testData/diagnostics/tests/operatorRem/resolveToModWhenNoOperatorRemFeature.txt

@@ -0,0 +1,40 @@
+package
+
+public fun takeInt(/*0*/ x: kotlin.Int): kotlin.Unit
+public fun test(): kotlin.Unit
+
+public object ModAndRem {
+    private constructor ModAndRem()
+    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 final operator fun mod(/*0*/ x: kotlin.Int): kotlin.Int
+    public final operator fun rem(/*0*/ x: kotlin.Int): kotlin.String
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public object ModAssignAndRemAssign {
+    private constructor ModAssignAndRemAssign()
+    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 final operator fun modAssign(/*0*/ x: kotlin.String): kotlin.Unit
+    public final operator fun remAssign(/*0*/ x: kotlin.Int): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public object OnlyRem {
+    private constructor OnlyRem()
+    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 final operator fun rem(/*0*/ x: kotlin.Int): kotlin.Unit
+    public final operator fun remAssign(/*0*/ x: kotlin.Int): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public object RemAndModAssign {
+    private constructor RemAndModAssign()
+    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 final operator fun modAssign(/*0*/ x: kotlin.Int): kotlin.Unit
+    public final operator fun rem(/*0*/ x: kotlin.Int): RemAndModAssign
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/tests/org/jetbrains/kotlin/checkers/DiagnosticsTestGenerated.java

@@ -13426,6 +13426,12 @@ public class DiagnosticsTestGenerated extends AbstractDiagnosticsTest {
                 doTest(fileName);
             }
 
+            @TestMetadata("resolveToModWhenNoOperatorRemFeature.kt")
+            public void testResolveToModWhenNoOperatorRemFeature() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/operatorRem/resolveToModWhenNoOperatorRemFeature.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("remAndRemAssignAmbiguity.kt")
             public void testRemAndRemAssignAmbiguity() throws Exception {
                 String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/operatorRem/remAndRemAssignAmbiguity.kt");