Compile actual and expected declarations together

#KT-20840 fixed

compiler/frontend/src/org/jetbrains/kotlin/analyzer/common/CommonAnalyzerFacade.kt

@@ -34,6 +34,7 @@ import org.jetbrains.kotlin.descriptors.PackagePartProvider
 import org.jetbrains.kotlin.descriptors.impl.CompositePackageFragmentProvider
 import org.jetbrains.kotlin.descriptors.impl.ModuleDescriptorImpl
 import org.jetbrains.kotlin.frontend.di.configureModule
+import org.jetbrains.kotlin.incremental.components.ExpectActualTracker
 import org.jetbrains.kotlin.incremental.components.LookupTracker
 import org.jetbrains.kotlin.load.kotlin.MetadataFinderFactory
 import org.jetbrains.kotlin.name.Name
@@ -142,6 +143,7 @@ object CommonAnalyzerFacade : AnalyzerFacade() {
 
         useInstance(moduleContentScope)
         useInstance(LookupTracker.DO_NOTHING)
+        useInstance(ExpectActualTracker.DoNothing)
         useImpl<ResolveSession>()
         useImpl<LazyTopDownAnalyzer>()
         useInstance(languageVersionSettings)

compiler/frontend/src/org/jetbrains/kotlin/config/CommonConfigurationKeys.kt

@@ -16,6 +16,7 @@
 
 package org.jetbrains.kotlin.config
 
+import org.jetbrains.kotlin.incremental.components.ExpectActualTracker
 import org.jetbrains.kotlin.incremental.components.LookupTracker
 
 object CommonConfigurationKeys {
@@ -33,6 +34,9 @@ object CommonConfigurationKeys {
 
     @JvmField
     val LOOKUP_TRACKER = CompilerConfigurationKey.create<LookupTracker>("lookup tracker")
+
+    @JvmField
+    val EXPECT_ACTUAL_TRACKER = CompilerConfigurationKey.create<ExpectActualTracker>("expect actual tracker")
 }
 
 var CompilerConfiguration.languageVersionSettings: LanguageVersionSettings

compiler/frontend/src/org/jetbrains/kotlin/frontend/di/injection.kt

@@ -25,6 +25,7 @@ import org.jetbrains.kotlin.container.useImpl
 import org.jetbrains.kotlin.container.useInstance
 import org.jetbrains.kotlin.context.ModuleContext
 import org.jetbrains.kotlin.extensions.StorageComponentContainerContributor
+import org.jetbrains.kotlin.incremental.components.ExpectActualTracker
 import org.jetbrains.kotlin.incremental.components.LookupTracker
 import org.jetbrains.kotlin.psi.KtFile
 import org.jetbrains.kotlin.resolve.*
@@ -127,6 +128,7 @@ fun createContainerForLazyLocalClassifierAnalyzer(
 
     useInstance(localClassDescriptorHolder)
     useInstance(lookupTracker)
+    useInstance(ExpectActualTracker.DoNothing)
 
     useImpl<LazyTopDownAnalyzer>()
 

compiler/frontend/src/org/jetbrains/kotlin/resolve/ModifiersChecker.java

@@ -25,6 +25,7 @@ import org.jetbrains.kotlin.config.LanguageVersionSettings;
 import org.jetbrains.kotlin.descriptors.*;
 import org.jetbrains.kotlin.diagnostics.DiagnosticFactory1;
 import org.jetbrains.kotlin.extensions.DeclarationAttributeAltererExtension;
+import org.jetbrains.kotlin.incremental.components.ExpectActualTracker;
 import org.jetbrains.kotlin.lexer.KtKeywordToken;
 import org.jetbrains.kotlin.lexer.KtModifierKeywordToken;
 import org.jetbrains.kotlin.lexer.KtTokens;
@@ -280,7 +281,7 @@ public class ModifiersChecker {
                 @NotNull DeclarationDescriptor descriptor
         ) {
             for (DeclarationChecker checker : declarationCheckers) {
-                checker.check(declaration, descriptor, trace, trace.getBindingContext(), languageVersionSettings);
+                checker.check(declaration, descriptor, trace, trace.getBindingContext(), languageVersionSettings, expectActualTracker);
             }
             OperatorModifierChecker.INSTANCE.check(declaration, descriptor, trace, languageVersionSettings);
             PublishedApiUsageChecker.INSTANCE.check(declaration, descriptor, trace);
@@ -304,14 +305,19 @@ public class ModifiersChecker {
     @NotNull
     private final LanguageVersionSettings languageVersionSettings;
 
+    @NotNull
+    private final ExpectActualTracker expectActualTracker;
+
     public ModifiersChecker(
             @NotNull AnnotationChecker annotationChecker,
             @NotNull Iterable<DeclarationChecker> declarationCheckers,
-            @NotNull LanguageVersionSettings languageVersionSettings
+            @NotNull LanguageVersionSettings languageVersionSettings,
+            @NotNull ExpectActualTracker expectActualTracker
     ) {
         this.annotationChecker = annotationChecker;
         this.declarationCheckers = declarationCheckers;
         this.languageVersionSettings = languageVersionSettings;
+        this.expectActualTracker = expectActualTracker;
     }
 
     @NotNull

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

@@ -19,6 +19,7 @@ package org.jetbrains.kotlin.resolve.checkers
 import org.jetbrains.kotlin.config.LanguageVersionSettings
 import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
 import org.jetbrains.kotlin.diagnostics.DiagnosticSink
+import org.jetbrains.kotlin.incremental.components.ExpectActualTracker
 import org.jetbrains.kotlin.psi.KtDeclaration
 import org.jetbrains.kotlin.resolve.BindingContext
 
@@ -29,7 +30,8 @@ interface DeclarationChecker {
             descriptor: DeclarationDescriptor,
             diagnosticHolder: DiagnosticSink,
             bindingContext: BindingContext,
-            languageVersionSettings: LanguageVersionSettings
+            languageVersionSettings: LanguageVersionSettings,
+            expectActualTracker: ExpectActualTracker
     )
 }
 
@@ -38,7 +40,9 @@ interface SimpleDeclarationChecker : DeclarationChecker {
             declaration: KtDeclaration,
             descriptor: DeclarationDescriptor,
             diagnosticHolder: DiagnosticSink,
-            bindingContext: BindingContext, languageVersionSettings: LanguageVersionSettings
+            bindingContext: BindingContext,
+            languageVersionSettings: LanguageVersionSettings,
+            expectActualTracker: ExpectActualTracker
     ) = check(declaration, descriptor, diagnosticHolder, bindingContext)
 
     fun check(

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

@@ -23,6 +23,7 @@ import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
 import org.jetbrains.kotlin.descriptors.Modality
 import org.jetbrains.kotlin.diagnostics.DiagnosticSink
 import org.jetbrains.kotlin.diagnostics.Errors.DELEGATED_MEMBER_HIDES_SUPERTYPE_OVERRIDE
+import org.jetbrains.kotlin.incremental.components.ExpectActualTracker
 import org.jetbrains.kotlin.psi.KtClassOrObject
 import org.jetbrains.kotlin.psi.KtDeclaration
 import org.jetbrains.kotlin.psi.KtDelegatedSuperTypeEntry
@@ -37,7 +38,8 @@ class DelegationChecker : DeclarationChecker {
             descriptor: DeclarationDescriptor,
             diagnosticHolder: DiagnosticSink,
             bindingContext: BindingContext,
-            languageVersionSettings: LanguageVersionSettings
+            languageVersionSettings: LanguageVersionSettings,
+            expectActualTracker: ExpectActualTracker
     ) {
         if (descriptor !is ClassDescriptor) return
         if (declaration !is KtClassOrObject) return

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

@@ -16,6 +16,7 @@
 
 package org.jetbrains.kotlin.resolve.checkers
 
+import com.intellij.openapi.vfs.VfsUtilCore
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns
 import org.jetbrains.kotlin.config.AnalysisFlag
 import org.jetbrains.kotlin.config.LanguageFeature
@@ -23,6 +24,7 @@ import org.jetbrains.kotlin.config.LanguageVersionSettings
 import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.diagnostics.DiagnosticSink
 import org.jetbrains.kotlin.diagnostics.Errors
+import org.jetbrains.kotlin.incremental.components.ExpectActualTracker
 import org.jetbrains.kotlin.incremental.components.NoLookupLocation
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.psi.KtConstructor
@@ -40,6 +42,7 @@ import org.jetbrains.kotlin.resolve.descriptorUtil.module
 import org.jetbrains.kotlin.resolve.scopes.DescriptorKindFilter
 import org.jetbrains.kotlin.resolve.scopes.MemberScope
 import org.jetbrains.kotlin.resolve.scopes.getDescriptorsFiltered
+import org.jetbrains.kotlin.resolve.source.PsiSourceFile
 import org.jetbrains.kotlin.types.KotlinType
 import org.jetbrains.kotlin.types.TypeConstructor
 import org.jetbrains.kotlin.types.TypeConstructorSubstitution
@@ -48,7 +51,9 @@ import org.jetbrains.kotlin.types.checker.NewKotlinTypeChecker
 import org.jetbrains.kotlin.types.checker.TypeCheckerContext
 import org.jetbrains.kotlin.types.typeUtil.asTypeProjection
 import org.jetbrains.kotlin.utils.SmartList
+import org.jetbrains.kotlin.utils.addToStdlib.safeAs
 import org.jetbrains.kotlin.utils.keysToMap
+import java.io.File
 
 object ExpectedActualDeclarationChecker : DeclarationChecker {
     override fun check(
@@ -56,7 +61,8 @@ object ExpectedActualDeclarationChecker : DeclarationChecker {
             descriptor: DeclarationDescriptor,
             diagnosticHolder: DiagnosticSink,
             bindingContext: BindingContext,
-            languageVersionSettings: LanguageVersionSettings
+            languageVersionSettings: LanguageVersionSettings,
+            expectActualTracker: ExpectActualTracker
     ) {
         if (!languageVersionSettings.supportsFeature(LanguageFeature.MultiPlatformProjects)) return
 
@@ -64,7 +70,7 @@ object ExpectedActualDeclarationChecker : DeclarationChecker {
         if (descriptor !is MemberDescriptor || DescriptorUtils.isEnumEntry(descriptor)) return
 
         if (descriptor.isExpect) {
-            checkExpectedDeclarationHasActual(declaration, descriptor, diagnosticHolder, descriptor.module)
+            checkExpectedDeclarationHasActual(declaration, descriptor, diagnosticHolder, descriptor.module, expectActualTracker)
         }
         else {
             val checkActual = !languageVersionSettings.getFlag(AnalysisFlag.multiPlatformDoNotCheckActual)
@@ -76,7 +82,8 @@ object ExpectedActualDeclarationChecker : DeclarationChecker {
             reportOn: KtNamedDeclaration,
             descriptor: MemberDescriptor,
             diagnosticHolder: DiagnosticSink,
-            platformModule: ModuleDescriptor
+            platformModule: ModuleDescriptor,
+            expectActualTracker: ExpectActualTracker
     ) {
         // Only look for top level actual members; class members will be handled as a part of that expected class
         if (descriptor.containingDeclaration !is PackageFragmentDescriptor) return
@@ -96,8 +103,32 @@ object ExpectedActualDeclarationChecker : DeclarationChecker {
             val incompatibility = compatibility as Map<Incompatible, Collection<MemberDescriptor>>
             diagnosticHolder.report(Errors.NO_ACTUAL_FOR_EXPECT.on(reportOn, descriptor, platformModule, incompatibility))
         }
+        else {
+            val actualMembers = compatibility.asSequence()
+                    .filter { (compatibility, _) ->
+                        compatibility is Compatible || (compatibility is Incompatible && compatibility.kind != Compatibility.IncompatibilityKind.STRONG)
+                    }.flatMap { it.value.asSequence() }
+
+            expectActualTracker?.reportExpectActual(expected = descriptor, actualMembers = actualMembers)
+        }
     }
 
+    private fun ExpectActualTracker.reportExpectActual(expected: MemberDescriptor, actualMembers: Sequence<MemberDescriptor>) {
+        if (this is ExpectActualTracker.DoNothing) return
+
+        val expectedFile = sourceFile(expected) ?: return
+        for (actual in actualMembers) {
+            val actualFile = sourceFile(actual) ?: continue
+            report(expectedFile = expectedFile, actualFile = actualFile)
+        }
+    }
+
+    private fun sourceFile(descriptor: MemberDescriptor): File? =
+            descriptor.source
+                    .containingFile
+                    .safeAs<PsiSourceFile>()
+                    ?.run { VfsUtilCore.virtualToIoFile(psiFile.virtualFile) }
+
     fun Map<out Compatibility, Collection<MemberDescriptor>>.allStrongIncompatibilities(): Boolean =
             this.keys.all { it is Incompatible && it.kind == Compatibility.IncompatibilityKind.STRONG }
 

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

@@ -22,6 +22,7 @@ import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
 import org.jetbrains.kotlin.descriptors.annotations.AnnotationDescriptor
 import org.jetbrains.kotlin.diagnostics.DiagnosticSink
 import org.jetbrains.kotlin.diagnostics.Errors
+import org.jetbrains.kotlin.incremental.components.ExpectActualTracker
 import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.psi.KtDeclaration
 import org.jetbrains.kotlin.resolve.BindingContext
@@ -37,7 +38,8 @@ abstract class KotlinVersionStringAnnotationValueChecker(
             descriptor: DeclarationDescriptor,
             diagnosticHolder: DiagnosticSink,
             bindingContext: BindingContext,
-            languageVersionSettings: LanguageVersionSettings
+            languageVersionSettings: LanguageVersionSettings,
+            expectActualTracker: ExpectActualTracker
     ) {
         val annotation = descriptor.annotations.findAnnotation(annotationFqName) ?: return
         val version = annotation.allValueArguments.values.singleOrNull()?.value as? String ?: return

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

@@ -24,6 +24,7 @@ import org.jetbrains.kotlin.descriptors.VariableDescriptor
 import org.jetbrains.kotlin.descriptors.impl.FunctionExpressionDescriptor
 import org.jetbrains.kotlin.diagnostics.DiagnosticSink
 import org.jetbrains.kotlin.diagnostics.Errors
+import org.jetbrains.kotlin.incremental.components.ExpectActualTracker
 import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.resolve.BindingContext
 
@@ -61,7 +62,8 @@ object UnderscoreChecker : DeclarationChecker {
             descriptor: DeclarationDescriptor,
             diagnosticHolder: DiagnosticSink,
             bindingContext: BindingContext,
-            languageVersionSettings: LanguageVersionSettings
+            languageVersionSettings: LanguageVersionSettings,
+            expectActualTracker: ExpectActualTracker
     ) {
         if (declaration is KtProperty && descriptor !is VariableDescriptor) return
         if (declaration is KtCallableDeclaration) {