[FE 1.0] Don't fail candidates which were marked with compatibility resolve previously

^KT-52431 Fixed
^KT-52393 Fixed

analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/DiagnosisCompilerTestFE10TestdataTestGenerated.java

@@ -15593,6 +15593,18 @@ public class DiagnosisCompilerTestFE10TestdataTestGenerated extends AbstractDiag
                     runTest("compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt52364.kt");
                 }
 
+                @Test
+                @TestMetadata("kt52393.kt")
+                public void testKt52393() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt52393.kt");
+                }
+
+                @Test
+                @TestMetadata("kt52431.kt")
+                public void testKt52431() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt52431.kt");
+                }
+
                 @Test
                 @TestMetadata("nullableEmptyIntersection.kt")
                 public void testNullableEmptyIntersection() throws Exception {

compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirOldFrontendDiagnosticsTestGenerated.java

@@ -15593,6 +15593,18 @@ public class FirOldFrontendDiagnosticsTestGenerated extends AbstractFirDiagnosti
                     runTest("compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt52364.kt");
                 }
 
+                @Test
+                @TestMetadata("kt52393.kt")
+                public void testKt52393() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt52393.kt");
+                }
+
+                @Test
+                @TestMetadata("kt52431.kt")
+                public void testKt52431() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt52431.kt");
+                }
+
                 @Test
                 @TestMetadata("nullableEmptyIntersection.kt")
                 public void testNullableEmptyIntersection() throws Exception {

compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirOldFrontendDiagnosticsWithLightTreeTestGenerated.java

@@ -15593,6 +15593,18 @@ public class FirOldFrontendDiagnosticsWithLightTreeTestGenerated extends Abstrac
                     runTest("compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt52364.kt");
                 }
 
+                @Test
+                @TestMetadata("kt52393.kt")
+                public void testKt52393() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt52393.kt");
+                }
+
+                @Test
+                @TestMetadata("kt52431.kt")
+                public void testKt52431() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt52431.kt");
+                }
+
                 @Test
                 @TestMetadata("nullableEmptyIntersection.kt")
                 public void testNullableEmptyIntersection() throws Exception {

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/ResolutionStages.kt

@@ -581,10 +581,10 @@ internal object CheckIncompatibleTypeVariableUpperBounds : ResolutionStage() {
                 val upperTypes = variableWithConstraints.constraints.extractUpperTypesToCheckIntersectionEmptiness()
 
                 // TODO: consider reporting errors on bounded type variables by incompatible types but with other lower constraints
-                if (
-                    variableWithConstraints.constraints.none { it.kind.isLower() }
-                    && upperTypes.computeEmptyIntersectionTypeKind().isDefinitelyEmpty()
-                ) {
+                if (upperTypes.size <= 1 || variableWithConstraints.constraints.any { it.kind.isLower() })
+                    continue
+
+                if (upperTypes.computeEmptyIntersectionTypeKind().isDefinitelyEmpty()) {
                     sink.yieldDiagnostic(
                         @Suppress("UNCHECKED_CAST")
                         InferredEmptyIntersectionDiagnostic(

compiler/resolution.common/src/org/jetbrains/kotlin/resolve/calls/inference/model/ConstraintPositionAndErrors.kt

@@ -152,7 +152,8 @@ class InferredEmptyIntersectionError(
 
 class OnlyInputTypesDiagnostic(val typeVariable: TypeVariableMarker) : ConstraintSystemError(INAPPLICABLE)
 
-object LowerPriorityToPreserveCompatibility : ConstraintSystemError(RESOLVED_NEED_PRESERVE_COMPATIBILITY)
+class LowerPriorityToPreserveCompatibility(val needToReportWarning: Boolean) :
+    ConstraintSystemError(RESOLVED_NEED_PRESERVE_COMPATIBILITY)
 
 fun Constraint.isExpectedTypePosition() =
     position.from is ExpectedTypeConstraintPosition<*> || position.from is DelegatedPropertyConstraintPosition<*>

compiler/resolution.common/src/org/jetbrains/kotlin/resolve/calls/inference/model/NewConstraintSystemImpl.kt

@@ -450,9 +450,13 @@ class NewConstraintSystemImpl(
             languageVersionSettings.supportsFeature(LanguageFeature.ForbidInferringTypeVariablesIntoEmptyIntersection)
         val upperTypes = intersectionTypeConstructor.supertypes()
 
+        // Diagnostic with these incompatible types has already been reported at the resolution stage
+        if (upperTypes.size <= 1 || storage.errors.any { it is InferredEmptyIntersection && it.incompatibleTypes == upperTypes })
+            return
+
         if (upperTypes.computeEmptyIntersectionTypeKind().isDefinitelyEmpty()) {
             // Remove existing errors from resolution stage because a completion error is more precise
-            storage.errors.removeIf { it is InferredEmptyIntersectionError || it is InferredEmptyIntersectionWarning }
+            storage.errors.removeIf { it is InferredEmptyIntersection }
             val errorFactory =
                 if (isInferredEmptyIntersectionForbidden) ::InferredEmptyIntersectionError else ::InferredEmptyIntersectionWarning
             addError(errorFactory(upperTypes, variable))

compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/components/ResolutionParts.kt

@@ -892,18 +892,23 @@ internal object CheckIncompatibleTypeVariableUpperBounds : ResolutionPart() {
         for (variableWithConstraints in getSystem().getBuilder().currentStorage().notFixedTypeVariables.values) {
             val upperTypes = variableWithConstraints.constraints.extractUpperTypesToCheckIntersectionEmptiness()
 
-            // TODO: consider reporting errors on bounded type variables by incompatible types but with other lower constraints
-            if (
-                variableWithConstraints.constraints.none { it.kind.isLower() }
-                && upperTypes.computeEmptyIntersectionTypeKind().isDefinitelyEmpty()
-            ) {
-                val isInferredEmptyIntersectionForbidden =
-                    callComponents.languageVersionSettings.supportsFeature(LanguageFeature.ForbidInferringTypeVariablesIntoEmptyIntersection)
+            when {
+                // TODO: consider reporting errors on bounded type variables by incompatible types but with other lower constraints
+                upperTypes.size <= 1 || variableWithConstraints.constraints.any { it.kind.isLower() } ->
+                    continue
+                wasPreviouslyDiscriminated(upperTypes) -> {
+                    markCandidateForCompatibilityResolve(needToReportWarning = false)
+                    continue
+                }
+                upperTypes.computeEmptyIntersectionTypeKind().isDefinitelyEmpty() -> {
+                    val isInferredEmptyIntersectionForbidden =
+                        callComponents.languageVersionSettings.supportsFeature(LanguageFeature.ForbidInferringTypeVariablesIntoEmptyIntersection)
 
-                val errorFactory = if (isInferredEmptyIntersectionForbidden || wasPreviouslyDiscriminated(upperTypes))
-                    ::InferredEmptyIntersectionError
-                else ::InferredEmptyIntersectionWarning
-                addError(errorFactory(upperTypes, variableWithConstraints.typeVariable))
+                    val errorFactory = if (isInferredEmptyIntersectionForbidden)
+                        ::InferredEmptyIntersectionError
+                    else ::InferredEmptyIntersectionWarning
+                    addError(errorFactory(upperTypes, variableWithConstraints.typeVariable))
+                }
             }
         }
     }

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

@@ -160,12 +160,15 @@ open class MutableResolvedCallAtom(
     override fun toString(): String = "$atom, candidate = $candidateDescriptor"
 }
 
-fun ResolutionCandidate.markCandidateForCompatibilityResolve() {
+fun ResolutionCandidate.markCandidateForCompatibilityResolve(needToReportWarning: Boolean = true) {
     if (callComponents.languageVersionSettings.supportsFeature(LanguageFeature.DisableCompatibilityModeForNewInference)) return
-    addDiagnostic(LowerPriorityToPreserveCompatibility.asDiagnostic())
+    addDiagnostic(LowerPriorityToPreserveCompatibility(needToReportWarning).asDiagnostic())
 }
 
-fun CallableReferencesCandidateFactory.markCandidateForCompatibilityResolve(diagnostics: SmartList<KotlinCallDiagnostic>) {
+fun CallableReferencesCandidateFactory.markCandidateForCompatibilityResolve(
+    diagnostics: SmartList<KotlinCallDiagnostic>,
+    needToReportWarning: Boolean = true,
+) {
     if (callComponents.languageVersionSettings.supportsFeature(LanguageFeature.DisableCompatibilityModeForNewInference)) return
-    diagnostics.add(LowerPriorityToPreserveCompatibility.asDiagnostic())
+    diagnostics.add(LowerPriorityToPreserveCompatibility(needToReportWarning).asDiagnostic())
 }

compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/tower/TowerResolver.kt

@@ -18,6 +18,9 @@ package org.jetbrains.kotlin.resolve.calls.tower
 
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.progress.ProgressIndicatorAndCompilationCanceledStatus
+import org.jetbrains.kotlin.resolve.calls.components.candidate.ResolutionCandidate
+import org.jetbrains.kotlin.resolve.calls.inference.model.LowerPriorityToPreserveCompatibility
+import org.jetbrains.kotlin.resolve.calls.model.constraintSystemError
 import org.jetbrains.kotlin.resolve.calls.tasks.ExplicitReceiverKind
 import org.jetbrains.kotlin.resolve.descriptorUtil.HIDES_MEMBERS_NAME_LIST
 import org.jetbrains.kotlin.resolve.scopes.HierarchicalScope
@@ -437,13 +440,21 @@ class TowerResolver {
             }
 
             if (firstGroupWithResolved == null) return null
-            if (compatibilityCandidate != null && compatibilityGroup !== firstGroupWithResolved) {
+            if (compatibilityCandidate != null
+                && compatibilityGroup !== firstGroupWithResolved
+                && needToReportCompatibilityWarning(compatibilityCandidate)
+            ) {
                 firstGroupWithResolved.forEach { it.addCompatibilityWarning(compatibilityCandidate) }
             }
 
             return firstGroupWithResolved.filter(::isSuccessfulCandidate)
         }
 
+        private fun needToReportCompatibilityWarning(candidate: C) = candidate is ResolutionCandidate &&
+                candidate.diagnostics.any {
+                    (it.constraintSystemError as? LowerPriorityToPreserveCompatibility)?.needToReportWarning == true
+                }
+
         private fun isSuccessfulCandidate(candidate: C): Boolean {
             return candidate.resultingApplicability == CandidateApplicability.RESOLVED
                     || candidate.resultingApplicability == CandidateApplicability.RESOLVED_WITH_ERROR

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt52393.fir.kt

@@ -0,0 +1,17 @@
+class Wrapper<T>
+
+class WrapperFunctions {
+    infix fun <T : Comparable<T>, S : T?> Wrapper<in S>.greaterEq(t: T): Unit = Unit
+
+    infix fun <T : Comparable<T>, S : T?> Wrapper<in S>.greaterEq(other: Wrapper<in S>): Unit = Unit // if this function is removed, it also works
+}
+
+fun main() {
+    val wrapper = Wrapper<Long>()
+    val number: Int = 5 // doesn't work
+//    val number: Long = 5 // works
+
+    with (WrapperFunctions()) {
+        <!ARGUMENT_TYPE_MISMATCH!>wrapper <!NONE_APPLICABLE!>greaterEq<!> number<!>
+    }
+}

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt52393.kt

@@ -0,0 +1,17 @@
+class Wrapper<T>
+
+class WrapperFunctions {
+    infix fun <T : Comparable<T>, S : T?> Wrapper<in S>.greaterEq(t: T): Unit = Unit
+
+    infix fun <T : Comparable<T>, S : T?> Wrapper<in S>.greaterEq(other: Wrapper<in S>): Unit = Unit // if this function is removed, it also works
+}
+
+fun main() {
+    val wrapper = Wrapper<Long>()
+    val number: Int = 5 // doesn't work
+//    val number: Long = 5 // works
+
+    with (WrapperFunctions()) {
+        wrapper <!INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION_WARNING!>greaterEq<!> number
+    }
+}

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt52393.txt

@@ -0,0 +1,19 @@
+package
+
+public fun main(): kotlin.Unit
+
+public final class Wrapper</*0*/ T> {
+    public constructor Wrapper</*0*/ T>()
+    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 final class WrapperFunctions {
+    public constructor WrapperFunctions()
+    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 final infix fun </*0*/ T : kotlin.Comparable<T>, /*1*/ S : T?> Wrapper<in S>.greaterEq(/*0*/ t: T): kotlin.Unit
+    public final infix fun </*0*/ T : kotlin.Comparable<T>, /*1*/ S : T?> Wrapper<in S>.greaterEq(/*0*/ other: Wrapper<in S>): kotlin.Unit
+}

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt52431.fir.kt

@@ -0,0 +1,13 @@
+interface Expression<K>
+
+interface ExpressionWithColumnType<K> : Expression<K>
+
+class Column<T>: ExpressionWithColumnType<T>
+
+infix fun <T : Comparable<T>, S : T?> ExpressionWithColumnType<in S>.less(t: T) {}
+
+infix fun <T : Comparable<T>, S : T?> Expression<in S>.less(other: Expression<in S>) {}
+
+fun main(x: Column<Long?>, y: Double) {
+    x <!NONE_APPLICABLE!>less<!> y // error in 1.7.20, no error in 1.7.0
+}

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt52431.kt

@@ -0,0 +1,13 @@
+interface Expression<K>
+
+interface ExpressionWithColumnType<K> : Expression<K>
+
+class Column<T>: ExpressionWithColumnType<T>
+
+infix fun <T : Comparable<T>, S : T?> ExpressionWithColumnType<in S>.less(t: T) {}
+
+infix fun <T : Comparable<T>, S : T?> Expression<in S>.less(other: Expression<in S>) {}
+
+fun main(x: Column<Long?>, y: Double) {
+    x <!INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION_WARNING!>less<!> y // error in 1.7.20, no error in 1.7.0
+}

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt52431.txt

@@ -0,0 +1,24 @@
+package
+
+public fun main(/*0*/ x: Column<kotlin.Long?>, /*1*/ y: kotlin.Double): kotlin.Unit
+public infix fun </*0*/ T : kotlin.Comparable<T>, /*1*/ S : T?> Expression<in S>.less(/*0*/ other: Expression<in S>): kotlin.Unit
+public infix fun </*0*/ T : kotlin.Comparable<T>, /*1*/ S : T?> ExpressionWithColumnType<in S>.less(/*0*/ t: T): kotlin.Unit
+
+public final class Column</*0*/ T> : ExpressionWithColumnType<T> {
+    public constructor Column</*0*/ T>()
+    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 Expression</*0*/ K> {
+    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 ExpressionWithColumnType</*0*/ K> : Expression<K> {
+    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
+}

compiler/testData/diagnostics/testsWithStdLib/greater.kt

@@ -8,5 +8,5 @@ fun <T : Comparable<T>, S : T?> Expression<in S>.greater(other: T): GreaterOp =
 fun foo(countExpr: Expression<Long>) {
     countExpr.greater(0)
     countExpr.<!INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION_WARNING!>greater<!>("0")
-    countExpr.<!INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION_WARNING!>greater<!><String, Nothing>("0")
+    countExpr.greater<String, Nothing>("0")
 }

compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/DiagnosticTestGenerated.java

@@ -15599,6 +15599,18 @@ public class DiagnosticTestGenerated extends AbstractDiagnosticTest {
                     runTest("compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt52364.kt");
                 }
 
+                @Test
+                @TestMetadata("kt52393.kt")
+                public void testKt52393() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt52393.kt");
+                }
+
+                @Test
+                @TestMetadata("kt52431.kt")
+                public void testKt52431() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt52431.kt");
+                }
+
                 @Test
                 @TestMetadata("nullableEmptyIntersection.kt")
                 public void testNullableEmptyIntersection() throws Exception {