Move ExpectActualCompatibility to :compiler:resolution.common

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

@@ -29,7 +29,7 @@ import org.jetbrains.kotlin.resolve.VarianceConflictDiagnosticData;
 import org.jetbrains.kotlin.resolve.calls.inference.InferenceErrorData;
 import org.jetbrains.kotlin.resolve.calls.model.ResolvedCall;
 import org.jetbrains.kotlin.resolve.calls.tower.WrongResolutionToClassifier;
-import org.jetbrains.kotlin.resolve.multiplatform.ExpectedActualResolver.Compatibility.Incompatible;
+import org.jetbrains.kotlin.resolve.multiplatform.ExpectActualCompatibility.Incompatible;
 import org.jetbrains.kotlin.serialization.deserialization.IncompatibleVersionErrorData;
 import org.jetbrains.kotlin.types.KotlinType;
 
@@ -704,10 +704,10 @@ public interface Errors {
     DiagnosticFactory0<PsiElement> EXPECTED_FUNCTION_SOURCE_WITH_DEFAULT_ARGUMENTS_NOT_FOUND = DiagnosticFactory0.create(ERROR);
 
     DiagnosticFactory3<KtNamedDeclaration, MemberDescriptor, ModuleDescriptor,
-            Map<Incompatible, Collection<MemberDescriptor>>> NO_ACTUAL_FOR_EXPECT =
+            Map<Incompatible<MemberDescriptor>, Collection<MemberDescriptor>>> NO_ACTUAL_FOR_EXPECT =
             DiagnosticFactory3.create(ERROR, INCOMPATIBLE_DECLARATION);
     DiagnosticFactory2<KtNamedDeclaration, MemberDescriptor,
-            Map<Incompatible, Collection<MemberDescriptor>>> ACTUAL_WITHOUT_EXPECT =
+            Map<Incompatible<MemberDescriptor>, Collection<MemberDescriptor>>> ACTUAL_WITHOUT_EXPECT =
             DiagnosticFactory2.create(ERROR, INCOMPATIBLE_DECLARATION);
     DiagnosticFactory2<KtNamedDeclaration, DeclarationDescriptor, Collection<ModuleDescriptor>> AMBIGUOUS_ACTUALS =
             DiagnosticFactory2.create(ERROR, INCOMPATIBLE_DECLARATION);
@@ -715,7 +715,7 @@ public interface Errors {
             DiagnosticFactory2.create(ERROR, INCOMPATIBLE_DECLARATION);
 
     DiagnosticFactory2<KtNamedDeclaration, ClassDescriptor,
-            List<Pair<MemberDescriptor, Map<Incompatible, Collection<MemberDescriptor>>>>> NO_ACTUAL_CLASS_MEMBER_FOR_EXPECTED_CLASS =
+            List<Pair<MemberDescriptor, Map<Incompatible<MemberDescriptor>, Collection<MemberDescriptor>>>>> NO_ACTUAL_CLASS_MEMBER_FOR_EXPECTED_CLASS =
             DiagnosticFactory2.create(ERROR, ACTUAL_DECLARATION_NAME);
     DiagnosticFactory0<KtNamedDeclaration> ACTUAL_MISSING = DiagnosticFactory0.create(ERROR, ACTUAL_DECLARATION_NAME);
 

compiler/frontend/src/org/jetbrains/kotlin/diagnostics/PositioningStrategies.kt

@@ -11,6 +11,7 @@ import com.intellij.psi.impl.source.tree.LeafPsiElement
 import com.intellij.psi.tree.TokenSet
 import org.jetbrains.kotlin.KtNodeTypes
 import org.jetbrains.kotlin.cfg.UnreachableCode
+import org.jetbrains.kotlin.descriptors.MemberDescriptor
 import org.jetbrains.kotlin.diagnostics.Errors.ACTUAL_WITHOUT_EXPECT
 import org.jetbrains.kotlin.diagnostics.Errors.NO_ACTUAL_FOR_EXPECT
 import org.jetbrains.kotlin.lexer.KtModifierKeywordToken
@@ -19,8 +20,8 @@ import org.jetbrains.kotlin.lexer.KtTokens.MODALITY_MODIFIERS
 import org.jetbrains.kotlin.lexer.KtTokens.VISIBILITY_MODIFIERS
 import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.psi.psiUtil.*
-import org.jetbrains.kotlin.resolve.multiplatform.ExpectedActualResolver.Compatibility.Incompatible
+import org.jetbrains.kotlin.resolve.multiplatform.ExpectActualCompatibility.Incompatible
-import org.jetbrains.kotlin.resolve.multiplatform.ExpectedActualResolver.Compatibility.Incompatible.*
+import org.jetbrains.kotlin.resolve.multiplatform.ExpectActualCompatibility.Incompatible.*
 import org.jetbrains.kotlin.utils.sure
 
 object PositioningStrategies {
@@ -114,7 +115,7 @@ object PositioningStrategies {
         }
     }
 
-    private val ParametrizedDiagnostic<out KtNamedDeclaration>.firstIncompatibility: Incompatible?
+    private val ParametrizedDiagnostic<out KtNamedDeclaration>.firstIncompatibility: Incompatible<MemberDescriptor>?
         get() {
             val map = when (factory) {
                 NO_ACTUAL_FOR_EXPECT ->

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

@@ -11,20 +11,21 @@ import kotlin.collections.CollectionsKt;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.jetbrains.kotlin.config.LanguageVersion;
+import org.jetbrains.kotlin.descriptors.MemberDescriptor;
 import org.jetbrains.kotlin.diagnostics.DiagnosticFactory;
 import org.jetbrains.kotlin.diagnostics.Errors;
 import org.jetbrains.kotlin.diagnostics.UnboundDiagnostic;
 import org.jetbrains.kotlin.metadata.deserialization.VersionRequirement;
 import org.jetbrains.kotlin.resolve.VarianceConflictDiagnosticData;
+import org.jetbrains.kotlin.resolve.multiplatform.ExpectActualCompatibility;
+import org.jetbrains.kotlin.resolve.multiplatform.ExpectActualCompatibility.Incompatible;
 import org.jetbrains.kotlin.types.KotlinTypeKt;
 import org.jetbrains.kotlin.util.OperatorNameConventions;
 import org.jetbrains.kotlin.utils.addToStdlib.AddToStdlibKt;
 
 import java.lang.reflect.Field;
 import java.lang.reflect.Modifier;
-import java.util.Collections;
+import java.util.*;
-import java.util.List;
-import java.util.ServiceLoader;
 
 import static org.jetbrains.kotlin.diagnostics.Errors.*;
 import static org.jetbrains.kotlin.diagnostics.rendering.Renderers.*;
@@ -307,16 +308,16 @@ public class DefaultErrorMessages {
                 "Please add the corresponding file to compilation sources");
 
         MAP.put(NO_ACTUAL_FOR_EXPECT, "Expected {0} has no actual declaration in module {1}{2}", DECLARATION_NAME_WITH_KIND,
-                MODULE_WITH_PLATFORM, PlatformIncompatibilityDiagnosticRenderer.TEXT);
+                MODULE_WITH_PLATFORM, adaptGenerics1(PlatformIncompatibilityDiagnosticRenderer.TEXT));
         MAP.put(ACTUAL_WITHOUT_EXPECT, "{0} has no corresponding expected declaration{1}", CAPITALIZED_DECLARATION_NAME_WITH_KIND_AND_PLATFORM,
-                PlatformIncompatibilityDiagnosticRenderer.TEXT);
+                adaptGenerics1(PlatformIncompatibilityDiagnosticRenderer.TEXT));
         MAP.put(AMBIGUOUS_ACTUALS, "{0} has several compatible actual declarations in modules {1}", CAPITALIZED_DECLARATION_NAME_WITH_KIND_AND_PLATFORM, commaSeparated(
                 MODULE));
         MAP.put(AMBIGUOUS_EXPECTS, "{0} has several compatible expect declarations in modules {1}", CAPITALIZED_DECLARATION_NAME_WITH_KIND_AND_PLATFORM, commaSeparated(
                 MODULE));
 
         MAP.put(NO_ACTUAL_CLASS_MEMBER_FOR_EXPECTED_CLASS, "Actual class ''{0}'' has no corresponding members for expected class members:{1}",
-                NAME, IncompatibleExpectedActualClassScopesRenderer.TEXT);
+                NAME, adaptGenerics2(IncompatibleExpectedActualClassScopesRenderer.TEXT));
         MAP.put(ACTUAL_MISSING, "Declaration must be marked with 'actual'");
 
         MAP.put(OPTIONAL_EXPECTATION_NOT_ON_EXPECTED, "'@OptionalExpectation' can only be used on an expected annotation class");
@@ -1100,6 +1101,15 @@ public class DefaultErrorMessages {
         }
     }
 
+    // Those methods are needed to fix problems with java type system and kotlin variance
+    public static DiagnosticParameterRenderer<Map<Incompatible<MemberDescriptor>, Collection<MemberDescriptor>>> adaptGenerics1(DiagnosticParameterRenderer<Map<Incompatible<? extends MemberDescriptor>, ? extends Collection<? extends MemberDescriptor>>> renderer) {
+        return (obj, renderingContext) -> renderer.render((Map)obj, renderingContext);
+    }
+
+    public static DiagnosticParameterRenderer<List<Pair<MemberDescriptor, Map<Incompatible<MemberDescriptor>, Collection<MemberDescriptor>>>>> adaptGenerics2(DiagnosticParameterRenderer<List<? extends Pair<? extends MemberDescriptor, ? extends Map<ExpectActualCompatibility.Incompatible<? extends MemberDescriptor>, ? extends Collection<? extends MemberDescriptor>>>>> renderer) {
+        return (obj, renderingContext) -> renderer.render((List)obj, renderingContext);
+    }
+
     private DefaultErrorMessages() {
     }
 }

compiler/frontend/src/org/jetbrains/kotlin/diagnostics/rendering/PlatformIncompatibilityDiagnosticRenderer.kt

@@ -18,13 +18,13 @@ package org.jetbrains.kotlin.diagnostics.rendering
 
 import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
 import org.jetbrains.kotlin.descriptors.MemberDescriptor
-import org.jetbrains.kotlin.resolve.multiplatform.ExpectedActualResolver.Compatibility.Incompatible
+import org.jetbrains.kotlin.resolve.multiplatform.ExpectActualCompatibility.Incompatible
 
 class PlatformIncompatibilityDiagnosticRenderer(
     private val mode: MultiplatformDiagnosticRenderingMode
-) : DiagnosticParameterRenderer<Map<Incompatible, Collection<MemberDescriptor>>> {
+) : DiagnosticParameterRenderer<Map<Incompatible<MemberDescriptor>, Collection<MemberDescriptor>>> {
     override fun render(
-        obj: Map<Incompatible, Collection<MemberDescriptor>>,
+        obj: Map<Incompatible<MemberDescriptor>, Collection<MemberDescriptor>>,
         renderingContext: RenderingContext
     ): String {
         if (obj.isEmpty()) return ""
@@ -43,9 +43,9 @@ class PlatformIncompatibilityDiagnosticRenderer(
 
 class IncompatibleExpectedActualClassScopesRenderer(
     private val mode: MultiplatformDiagnosticRenderingMode
-) : DiagnosticParameterRenderer<List<Pair<MemberDescriptor, Map<Incompatible, Collection<MemberDescriptor>>>>> {
+) : DiagnosticParameterRenderer<List<Pair<MemberDescriptor, Map<Incompatible<MemberDescriptor>, Collection<MemberDescriptor>>>>> {
     override fun render(
-        obj: List<Pair<MemberDescriptor, Map<Incompatible, Collection<MemberDescriptor>>>>,
+        obj: List<Pair<MemberDescriptor, Map<Incompatible<MemberDescriptor>, Collection<MemberDescriptor>>>>,
         renderingContext: RenderingContext
     ): String {
         if (obj.isEmpty()) return ""
@@ -82,7 +82,7 @@ open class MultiplatformDiagnosticRenderingMode {
 }
 
 private fun StringBuilder.renderIncompatibilityInformation(
-    map: Map<Incompatible, Collection<MemberDescriptor>>,
+    map: Map<Incompatible<MemberDescriptor>, Collection<MemberDescriptor>>,
     indent: String,
     context: RenderingContext,
     mode: MultiplatformDiagnosticRenderingMode
@@ -109,7 +109,7 @@ private fun StringBuilder.renderIncompatibilityInformation(
 }
 
 private fun StringBuilder.renderIncompatibleClassScopes(
-    unfulfilled: List<Pair<MemberDescriptor, Map<Incompatible, Collection<MemberDescriptor>>>>,
+    unfulfilled: List<Pair<MemberDescriptor, Map<Incompatible<MemberDescriptor>, Collection<MemberDescriptor>>>>,
     indent: String,
     context: RenderingContext,
     mode: MultiplatformDiagnosticRenderingMode

compiler/frontend/src/org/jetbrains/kotlin/resolve/checkers/ExpectedActualDeclarationChecker.kt

@@ -33,10 +33,9 @@ import org.jetbrains.kotlin.resolve.constants.ConstantValue
 import org.jetbrains.kotlin.resolve.descriptorUtil.isAnnotationConstructor
 import org.jetbrains.kotlin.resolve.descriptorUtil.isPrimaryConstructorOfInlineClass
 import org.jetbrains.kotlin.resolve.descriptorUtil.module
+import org.jetbrains.kotlin.resolve.multiplatform.ExpectActualCompatibility
+import org.jetbrains.kotlin.resolve.multiplatform.ExpectActualCompatibility.*
 import org.jetbrains.kotlin.resolve.multiplatform.ExpectedActualResolver
-import org.jetbrains.kotlin.resolve.multiplatform.ExpectedActualResolver.Compatibility
-import org.jetbrains.kotlin.resolve.multiplatform.ExpectedActualResolver.Compatibility.Compatible
-import org.jetbrains.kotlin.resolve.multiplatform.ExpectedActualResolver.Compatibility.Incompatible
 import org.jetbrains.kotlin.resolve.multiplatform.ModuleFilter
 import org.jetbrains.kotlin.resolve.multiplatform.OptionalAnnotationUtil
 import org.jetbrains.kotlin.resolve.source.PsiSourceFile
@@ -136,7 +135,7 @@ class ExpectedActualDeclarationChecker(
         val compatibility = path.nodes
             .mapNotNull { ExpectedActualResolver.findActualForExpected(descriptor, it, moduleVisibilityFilter) }
             .ifEmpty { return }
-            .fold(LinkedHashMap<Compatibility, List<MemberDescriptor>>()) { resultMap, partialMap ->
+            .fold(LinkedHashMap<ExpectActualCompatibility<MemberDescriptor>, List<MemberDescriptor>>()) { resultMap, partialMap ->
                 resultMap.apply { putAll(partialMap) }
             }
 
@@ -180,7 +179,7 @@ class ExpectedActualDeclarationChecker(
         ) {
             assert(compatibility.keys.all { it is Incompatible })
             @Suppress("UNCHECKED_CAST")
-            val incompatibility = compatibility as Map<Incompatible, Collection<MemberDescriptor>>
+            val incompatibility = compatibility as Map<Incompatible<MemberDescriptor>, Collection<MemberDescriptor>>
             trace.report(Errors.NO_ACTUAL_FOR_EXPECT.on(reportOn, descriptor, module, incompatibility))
             return
         }
@@ -188,14 +187,14 @@ class ExpectedActualDeclarationChecker(
         // Here we have exactly one compatible actual and/or some weakly incompatible. In either case, we don't report anything on expect
         val actualMembers = compatibility.asSequence()
             .filter { (compatibility, _) ->
-                compatibility is Compatible || (compatibility is Incompatible && compatibility.kind != Compatibility.IncompatibilityKind.STRONG)
+                compatibility is Compatible || (compatibility is Incompatible && compatibility.kind != IncompatibilityKind.STRONG)
             }.flatMap { it.value.asSequence() }
 
         expectActualTracker.reportExpectActual(expected = descriptor, actualMembers = actualMembers)
     }
 
     private fun MemberDescriptor.hasNoActualWithDiagnostic(
-        compatibility: Map<Compatibility, List<MemberDescriptor>>
+        compatibility: Map<ExpectActualCompatibility<MemberDescriptor>, List<MemberDescriptor>>
     ): Boolean {
         return compatibility.values.flatMapTo(hashSetOf()) { it }.all { actual ->
             val expectedOnes = ExpectedActualResolver.findExpectedForActual(actual, module)
@@ -257,7 +256,7 @@ class ExpectedActualDeclarationChecker(
             // This is needed only to reduce the number of errors. Incompatibility errors for those members will be reported
             // later when this checker is called for them
             fun hasSingleActualSuspect(
-                expectedWithIncompatibility: Pair<MemberDescriptor, Map<Incompatible, Collection<MemberDescriptor>>>
+                expectedWithIncompatibility: Pair<MemberDescriptor, Map<Incompatible<MemberDescriptor>, Collection<MemberDescriptor>>>
             ): Boolean {
                 val (expectedMember, incompatibility) = expectedWithIncompatibility
                 val actualMember = incompatibility.values.singleOrNull()?.singleOrNull()
@@ -285,7 +284,7 @@ class ExpectedActualDeclarationChecker(
         } else if (Compatible !in compatibility) {
             assert(compatibility.keys.all { it is Incompatible })
             @Suppress("UNCHECKED_CAST")
-            val incompatibility = compatibility as Map<Incompatible, Collection<MemberDescriptor>>
+            val incompatibility = compatibility as Map<Incompatible<MemberDescriptor>, Collection<MemberDescriptor>>
             trace.report(Errors.ACTUAL_WITHOUT_EXPECT.on(reportOn, descriptor, incompatibility))
         } else {
             val expected = compatibility[Compatible]!!.first()
@@ -302,7 +301,7 @@ class ExpectedActualDeclarationChecker(
     }
 
     private fun checkAmbiguousExpects(
-        compatibility: Map<Compatibility, List<MemberDescriptor>>,
+        compatibility: Map<ExpectActualCompatibility<MemberDescriptor>, List<MemberDescriptor>>,
         trace: BindingTrace,
         reportOn: KtNamedDeclaration,
         descriptor: MemberDescriptor
@@ -322,9 +321,9 @@ class ExpectedActualDeclarationChecker(
         }
     }
 
-    private fun Compatibility.isCompatibleOrWeakCompatible() =
+    private fun ExpectActualCompatibility<MemberDescriptor>.isCompatibleOrWeakCompatible() =
         this is Compatible ||
-                this is Incompatible && kind == ExpectedActualResolver.Compatibility.IncompatibilityKind.WEAK
+                this is Incompatible && kind == IncompatibilityKind.WEAK
 
     // we don't require `actual` modifier on
     //  - annotation constructors, because annotation classes can only have one constructor
@@ -390,7 +389,7 @@ class ExpectedActualDeclarationChecker(
     }
 
     companion object {
-        fun Map<out Compatibility, Collection<MemberDescriptor>>.allStrongIncompatibilities(): Boolean =
+        fun Map<out ExpectActualCompatibility<MemberDescriptor>, Collection<MemberDescriptor>>.allStrongIncompatibilities(): Boolean =
-            this.keys.all { it is Incompatible && it.kind == Compatibility.IncompatibilityKind.STRONG }
+            this.keys.all { it is Incompatible && it.kind == IncompatibilityKind.STRONG }
     }
 }

compiler/resolution.common/src/org/jetbrains/kotlin/resolve/multiplatform/ExpectActualCompatibility.kt

@@ -0,0 +1,90 @@
+/*
+ * Copyright 2010-2021 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.multiplatform
+
+sealed class ExpectActualCompatibility<out D> {
+    // For IncompatibilityKind.STRONG `actual` declaration is considered as overload and error reports on expected declaration
+    enum class IncompatibilityKind {
+        WEAK, STRONG
+    }
+
+    // Note that the reason is used in the diagnostic output, see PlatformIncompatibilityDiagnosticRenderer
+    sealed class Incompatible<out D>(
+        val reason: String?,
+        val kind: IncompatibilityKind = IncompatibilityKind.WEAK
+    ) : ExpectActualCompatibility<D>() {
+        // Callables
+
+        object CallableKind : Incompatible<Nothing>(
+            "callable kinds are different (function vs property)",
+            IncompatibilityKind.STRONG
+        )
+
+        object ParameterShape : Incompatible<Nothing>(
+            "parameter shapes are different (extension vs non-extension)",
+            IncompatibilityKind.STRONG
+        )
+
+        object ParameterCount : Incompatible<Nothing>("number of value parameters is different", IncompatibilityKind.STRONG)
+        object TypeParameterCount : Incompatible<Nothing>("number of type parameters is different", IncompatibilityKind.STRONG)
+
+        object ParameterTypes : Incompatible<Nothing>("parameter types are different", IncompatibilityKind.STRONG)
+        object ReturnType : Incompatible<Nothing>("return type is different", IncompatibilityKind.STRONG)
+
+        object ParameterNames : Incompatible<Nothing>("parameter names are different")
+        object TypeParameterNames : Incompatible<Nothing>("names of type parameters are different")
+
+        object ValueParameterVararg : Incompatible<Nothing>("some value parameter is vararg in one declaration and non-vararg in the other")
+        object ValueParameterNoinline : Incompatible<Nothing>(
+            "some value parameter is noinline in one declaration and not noinline in the other"
+        )
+
+        object ValueParameterCrossinline : Incompatible<Nothing>(
+            "some value parameter is crossinline in one declaration and not crossinline in the other"
+        )
+
+        // Functions
+
+        object FunctionModifiersDifferent : Incompatible<Nothing>("modifiers are different (suspend)")
+        object FunctionModifiersNotSubset : Incompatible<Nothing>(
+            "some modifiers on expected declaration are missing on the actual one (external, infix, inline, operator, tailrec)"
+        )
+
+        // Properties
+
+        object PropertyKind : Incompatible<Nothing>("property kinds are different (val vs var)")
+        object PropertyModifiers : Incompatible<Nothing>("modifiers are different (const, lateinit)")
+
+        // Classifiers
+
+        object ClassKind : Incompatible<Nothing>("class kinds are different (class, interface, object, enum, annotation)")
+
+        object ClassModifiers : Incompatible<Nothing>("modifiers are different (companion, inner, inline)")
+
+        object Supertypes : Incompatible<Nothing>("some supertypes are missing in the actual declaration")
+
+        class ClassScopes<D>(
+            val unfulfilled: List<Pair<D, Map<Incompatible<D>, Collection<D>>>>
+        ) : Incompatible<D>("some expected members have no actual ones")
+
+        object EnumEntries : Incompatible<Nothing>("some entries from expected enum are missing in the actual enum")
+
+        // Common
+
+        object Modality : Incompatible<Nothing>("modality is different")
+        object Visibility : Incompatible<Nothing>("visibility is different")
+
+        object TypeParameterUpperBounds : Incompatible<Nothing>("upper bounds of type parameters are different", IncompatibilityKind.STRONG)
+        object TypeParameterVariance : Incompatible<Nothing>("declaration-site variances of type parameters are different")
+        object TypeParameterReified : Incompatible<Nothing>(
+            "some type parameter is reified in one declaration and non-reified in the other"
+        )
+
+        object Unknown : Incompatible<Nothing>(null)
+    }
+
+    object Compatible : ExpectActualCompatibility<Nothing>()
+}

compiler/resolution/src/org/jetbrains/kotlin/resolve/multiplatform/ExpectedActualResolver.kt

@@ -13,8 +13,8 @@ import org.jetbrains.kotlin.resolve.DescriptorUtils
 import org.jetbrains.kotlin.resolve.descriptorUtil.classId
 import org.jetbrains.kotlin.resolve.descriptorUtil.isAnnotationConstructor
 import org.jetbrains.kotlin.resolve.descriptorUtil.module
-import org.jetbrains.kotlin.resolve.multiplatform.ExpectedActualResolver.Compatibility.Compatible
+import org.jetbrains.kotlin.resolve.multiplatform.ExpectActualCompatibility.Compatible
-import org.jetbrains.kotlin.resolve.multiplatform.ExpectedActualResolver.Compatibility.Incompatible
+import org.jetbrains.kotlin.resolve.multiplatform.ExpectActualCompatibility.Incompatible
 import org.jetbrains.kotlin.resolve.scopes.DescriptorKindFilter
 import org.jetbrains.kotlin.resolve.scopes.MemberScope
 import org.jetbrains.kotlin.resolve.scopes.getDescriptorsFiltered
@@ -49,7 +49,7 @@ object ExpectedActualResolver {
         expected: MemberDescriptor,
         platformModule: ModuleDescriptor,
         moduleVisibilityFilter: ModuleFilter = onlyFromThisModule(platformModule)
-    ): Map<Compatibility, List<MemberDescriptor>>? {
+    ): Map<ExpectActualCompatibility<MemberDescriptor>, List<MemberDescriptor>>? {
         return when (expected) {
             is CallableMemberDescriptor -> {
                 expected.findNamesakesFromModule(platformModule, moduleVisibilityFilter).filter { actual ->
@@ -78,7 +78,7 @@ object ExpectedActualResolver {
         actual: MemberDescriptor,
         commonModule: ModuleDescriptor,
         moduleFilter: (ModuleDescriptor) -> Boolean = onlyFromThisModule(commonModule)
-    ): Map<Compatibility, List<MemberDescriptor>>? {
+    ): Map<ExpectActualCompatibility<MemberDescriptor>, List<MemberDescriptor>>? {
         return when (actual) {
             is CallableMemberDescriptor -> {
                 val container = actual.containingDeclaration
@@ -180,79 +180,13 @@ object ExpectedActualResolver {
         return classifiers
     }
 
-    sealed class Compatibility {
-        // For IncompatibilityKind.STRONG `actual` declaration is considered as overload and error reports on expected declaration
-        enum class IncompatibilityKind {
-            WEAK, STRONG
-        }
-
-        // Note that the reason is used in the diagnostic output, see PlatformIncompatibilityDiagnosticRenderer
-        sealed class Incompatible(val reason: String?, val kind: IncompatibilityKind = IncompatibilityKind.WEAK) : Compatibility() {
-            // Callables
-
-            object CallableKind : Incompatible("callable kinds are different (function vs property)", IncompatibilityKind.STRONG)
-
-            object ParameterShape : Incompatible("parameter shapes are different (extension vs non-extension)", IncompatibilityKind.STRONG)
-
-            object ParameterCount : Incompatible("number of value parameters is different", IncompatibilityKind.STRONG)
-            object TypeParameterCount : Incompatible("number of type parameters is different", IncompatibilityKind.STRONG)
-
-            object ParameterTypes : Incompatible("parameter types are different", IncompatibilityKind.STRONG)
-            object ReturnType : Incompatible("return type is different", IncompatibilityKind.STRONG)
-
-            object ParameterNames : Incompatible("parameter names are different")
-            object TypeParameterNames : Incompatible("names of type parameters are different")
-
-            object ValueParameterVararg : Incompatible("some value parameter is vararg in one declaration and non-vararg in the other")
-            object ValueParameterNoinline : Incompatible("some value parameter is noinline in one declaration and not noinline in the other")
-            object ValueParameterCrossinline : Incompatible("some value parameter is crossinline in one declaration and not crossinline in the other")
-
-            // Functions
-
-            object FunctionModifiersDifferent : Incompatible("modifiers are different (suspend)")
-            object FunctionModifiersNotSubset : Incompatible("some modifiers on expected declaration are missing on the actual one (external, infix, inline, operator, tailrec)")
-
-            // Properties
-
-            object PropertyKind : Incompatible("property kinds are different (val vs var)")
-            object PropertyModifiers : Incompatible("modifiers are different (const, lateinit)")
-
-            // Classifiers
-
-            object ClassKind : Incompatible("class kinds are different (class, interface, object, enum, annotation)")
-
-            object ClassModifiers : Incompatible("modifiers are different (companion, inner, inline)")
-
-            object Supertypes : Incompatible("some supertypes are missing in the actual declaration")
-
-            class ClassScopes(
-                val unfulfilled: List<Pair<MemberDescriptor, Map<Incompatible, Collection<MemberDescriptor>>>>
-            ) : Incompatible("some expected members have no actual ones")
-
-            object EnumEntries : Incompatible("some entries from expected enum are missing in the actual enum")
-
-            // Common
-
-            object Modality : Incompatible("modality is different")
-            object Visibility : Incompatible("visibility is different")
-
-            object TypeParameterUpperBounds : Incompatible("upper bounds of type parameters are different", IncompatibilityKind.STRONG)
-            object TypeParameterVariance : Incompatible("declaration-site variances of type parameters are different")
-            object TypeParameterReified : Incompatible("some type parameter is reified in one declaration and non-reified in the other")
-
-            object Unknown : Incompatible(null)
-        }
-
-        object Compatible : Compatibility()
-    }
-
     // a is the declaration in common code, b is the definition in the platform-specific code
     private fun areCompatibleCallables(
         a: CallableMemberDescriptor,
         b: CallableMemberDescriptor,
         platformModule: ModuleDescriptor = b.module,
         parentSubstitutor: Substitutor? = null
-    ): Compatibility {
+    ): ExpectActualCompatibility<MemberDescriptor> {
         assert(a.name == b.name) {
             "This function should be invoked only for declarations with the same name: $a, $b"
         }
@@ -376,7 +310,7 @@ object ExpectedActualResolver {
         b: List<TypeParameterDescriptor>,
         platformModule: ModuleDescriptor,
         substitutor: Substitutor
-    ): Compatibility {
+    ): ExpectActualCompatibility<MemberDescriptor> {
         for (i in a.indices) {
             val aBounds = a[i].upperBounds
             val bBounds = b[i].upperBounds
@@ -393,7 +327,7 @@ object ExpectedActualResolver {
         return Compatible
     }
 
-    private fun areCompatibleFunctions(a: FunctionDescriptor, b: FunctionDescriptor): Compatibility {
+    private fun areCompatibleFunctions(a: FunctionDescriptor, b: FunctionDescriptor): ExpectActualCompatibility<MemberDescriptor> {
         if (!equalBy(a, b) { f -> f.isSuspend }) return Incompatible.FunctionModifiersDifferent
 
         if (a.isExternal && !b.isExternal ||
@@ -405,14 +339,14 @@ object ExpectedActualResolver {
         return Compatible
     }
 
-    private fun areCompatibleProperties(a: PropertyDescriptor, b: PropertyDescriptor): Compatibility {
+    private fun areCompatibleProperties(a: PropertyDescriptor, b: PropertyDescriptor): ExpectActualCompatibility<MemberDescriptor> {
         if (!equalBy(a, b) { p -> p.isVar }) return Incompatible.PropertyKind
         if (!equalBy(a, b) { p -> listOf(p.isConst, p.isLateInit) }) return Incompatible.PropertyModifiers
 
         return Compatible
     }
 
-    private fun areCompatibleClassifiers(a: ClassDescriptor, other: ClassifierDescriptor): Compatibility {
+    private fun areCompatibleClassifiers(a: ClassDescriptor, other: ClassifierDescriptor): ExpectActualCompatibility<MemberDescriptor> {
         // Can't check FQ names here because nested expected class may be implemented via actual typealias's expansion with the other FQ name
         assert(a.name == other.name) { "This function should be invoked only for declarations with the same name: $a, $other" }
 
@@ -476,8 +410,8 @@ object ExpectedActualResolver {
         b: ClassDescriptor,
         platformModule: ModuleDescriptor,
         substitutor: Substitutor
-    ): Compatibility {
+    ): ExpectActualCompatibility<MemberDescriptor> {
-        val unfulfilled = arrayListOf<Pair<MemberDescriptor, Map<Incompatible, MutableCollection<MemberDescriptor>>>>()
+        val unfulfilled = arrayListOf<Pair<MemberDescriptor, Map<Incompatible<MemberDescriptor>, MutableCollection<MemberDescriptor>>>>()
 
         val bMembersByName = b.getMembers().groupBy { it.name }
 
@@ -500,7 +434,7 @@ object ExpectedActualResolver {
             }
             if (mapping.values.any { it == Compatible }) continue
 
-            val incompatibilityMap = mutableMapOf<Incompatible, MutableCollection<MemberDescriptor>>()
+            val incompatibilityMap = mutableMapOf<Incompatible<MemberDescriptor>, MutableCollection<MemberDescriptor>>()
             for ((descriptor, compatibility) in mapping) {
                 when (compatibility) {
                     Compatible -> continue@outer

idea/idea-analysis/src/org/jetbrains/kotlin/idea/util/expectActualUtil.kt

@@ -26,6 +26,7 @@ import org.jetbrains.kotlin.resolve.DescriptorToSourceUtils
 import org.jetbrains.kotlin.resolve.DescriptorUtils
 import org.jetbrains.kotlin.resolve.descriptorUtil.module
 import org.jetbrains.kotlin.resolve.lazy.BodyResolveMode
+import org.jetbrains.kotlin.resolve.multiplatform.ExpectActualCompatibility
 import org.jetbrains.kotlin.resolve.multiplatform.ExpectedActualResolver
 
 internal fun MemberDescriptor.expectedDescriptors() =
@@ -74,7 +75,7 @@ fun ModuleDescriptor.hasDeclarationOf(descriptor: MemberDescriptor) = declaratio
 private fun ModuleDescriptor.declarationOf(descriptor: MemberDescriptor): DeclarationDescriptor? =
     with(ExpectedActualResolver) {
         val expectedCompatibilityMap = findExpectedForActual(descriptor, this@declarationOf)
-        expectedCompatibilityMap?.get(ExpectedActualResolver.Compatibility.Compatible)?.firstOrNull()
+        expectedCompatibilityMap?.get(ExpectActualCompatibility.Compatible)?.firstOrNull()
             ?: expectedCompatibilityMap?.values?.flatten()?.firstOrNull()
     }
 
@@ -181,4 +182,4 @@ fun KtDeclaration.runCommandOnAllExpectAndActualDeclaration(
     } else {
         project.executeCommand(command, command = ::process)
     }
-}
+}

idea/src/org/jetbrains/kotlin/idea/inspections/OptionalExpectationInspection.kt

@@ -26,6 +26,7 @@ import org.jetbrains.kotlin.resolve.checkers.ExpectedActualDeclarationChecker.Co
 import org.jetbrains.kotlin.resolve.descriptorUtil.module
 import org.jetbrains.kotlin.resolve.multiplatform.ExpectedActualResolver
 import org.jetbrains.kotlin.resolve.multiplatform.OptionalAnnotationUtil
+import org.jetbrains.kotlin.resolve.multiplatform.ExpectActualCompatibility
 
 class OptionalExpectationInspection : AbstractKotlinInspection() {
     override fun buildVisitor(holder: ProblemsHolder, isOnTheFly: Boolean, session: LocalInspectionToolSession) =
@@ -43,12 +44,12 @@ class OptionalExpectationInspection : AbstractKotlinInspection() {
             for (actualModuleDescriptor in implementingModules) {
                 val compatibility = ExpectedActualResolver.findActualForExpected(descriptor, actualModuleDescriptor) ?: continue
                 if (!compatibility.allStrongIncompatibilities() &&
-                    (ExpectedActualResolver.Compatibility.Compatible in compatibility ||
+                    (ExpectActualCompatibility.Compatible in compatibility ||
                             !compatibility.values.flatMapTo(
                                 hashSetOf()
                             ) { it }.all { actual ->
                                 val expectedOnes = ExpectedActualResolver.findExpectedForActual(actual, descriptor.module)
-                                expectedOnes != null && ExpectedActualResolver.Compatibility.Compatible in expectedOnes.keys
+                                expectedOnes != null && ExpectActualCompatibility.Compatible in expectedOnes.keys
                             })
                 ) continue
                 val platform = actualModuleDescriptor.platform ?: continue
@@ -69,4 +70,4 @@ class OptionalExpectationInspection : AbstractKotlinInspection() {
                 )
             }
         })
-}
+}