[FIR] Support of ACTUAL_TYPE_ALIAS_NOT_TO_CLASS diagnostic

^KT-56514 Fixed

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/CommonDeclarationCheckers.kt

@@ -32,7 +32,6 @@ object CommonDeclarationCheckers : DeclarationCheckers() {
             FirAnnotationChecker,
             FirPublishedApiChecker,
             FirOptInMarkedDeclarationChecker,
-            FirActualDeclarationChecker,
         )
 
     override val callableDeclarationCheckers: Set<FirCallableDeclarationChecker>
@@ -40,6 +39,7 @@ object CommonDeclarationCheckers : DeclarationCheckers() {
             FirKClassWithIncorrectTypeArgumentChecker,
             FirImplicitNothingReturnTypeChecker,
             FirDynamicReceiverChecker,
+            FirActualCallableDeclarationChecker,
         )
 
     override val functionCheckers: Set<FirFunctionChecker>
@@ -152,6 +152,7 @@ object CommonDeclarationCheckers : DeclarationCheckers() {
     override val typeAliasCheckers: Set<FirTypeAliasChecker>
         get() = setOf(
             FirTopLevelTypeAliasChecker,
+            FirActualTypeAliasChecker,
         )
 
     override val anonymousFunctionCheckers: Set<FirAnonymousFunctionChecker>

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirActualCallableDeclarationChecker.kt

@@ -0,0 +1,71 @@
+/*
+ * Copyright 2010-2023 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.fir.analysis.checkers.declaration
+
+import org.jetbrains.kotlin.diagnostics.DiagnosticReporter
+import org.jetbrains.kotlin.diagnostics.reportOn
+import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
+import org.jetbrains.kotlin.fir.analysis.checkers.getContainingClassSymbol
+import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors
+import org.jetbrains.kotlin.fir.declarations.*
+import org.jetbrains.kotlin.fir.declarations.utils.isActual
+import org.jetbrains.kotlin.fir.symbols.FirBasedSymbol
+import org.jetbrains.kotlin.fir.symbols.impl.FirCallableSymbol
+import org.jetbrains.kotlin.fir.types.*
+import org.jetbrains.kotlin.resolve.multiplatform.ExpectActualCompatibility
+
+object FirActualCallableDeclarationChecker : FirCallableDeclarationChecker() {
+    override fun check(declaration: FirCallableDeclaration, context: CheckerContext, reporter: DiagnosticReporter) {
+        if (!declaration.isActual) return
+
+        if (declaration is FirFunction) {
+            checkActualFunctionWithDefaultArguments(declaration, reporter, context)
+        }
+        checkReturnTypes(declaration, context, reporter)
+    }
+
+    private fun checkActualFunctionWithDefaultArguments(function: FirFunction, reporter: DiagnosticReporter, context: CheckerContext) {
+        for (valueParameter in function.valueParameters) {
+            if (valueParameter.defaultValue != null) {
+                reporter.reportOn(valueParameter.source, FirErrors.ACTUAL_FUNCTION_WITH_DEFAULT_ARGUMENTS, context)
+            }
+        }
+    }
+
+    private fun checkReturnTypes(callableDeclaration: FirCallableDeclaration, context: CheckerContext, reporter: DiagnosticReporter) {
+        val actualFunctionSymbol = callableDeclaration.symbol
+        val expectFunctionSymbol = actualFunctionSymbol.getSingleCompatibleExpectForActualOrNull() as? FirCallableSymbol ?: return
+
+        val expectTypeParameters = expectFunctionSymbol.getContainingClassSymbol(expectFunctionSymbol.moduleData.session)
+            ?.typeParameterSymbols.orEmpty()
+        val actualClassTypeParameters = actualFunctionSymbol.getContainingClassSymbol(context.session)?.typeParameterSymbols.orEmpty()
+        val parentSubstitutor =
+            createExpectActualTypeParameterSubstitutor(expectTypeParameters, actualClassTypeParameters, context.session)
+
+        val substitutor = createExpectActualTypeParameterSubstitutor(
+            expectFunctionSymbol.typeParameterSymbols,
+            actualFunctionSymbol.typeParameterSymbols,
+            context.session,
+            parentSubstitutor
+        )
+
+        if (!areCompatibleExpectActualTypes(
+                substitutor.substituteOrSelf(expectFunctionSymbol.resolvedReturnType.type),
+                actualFunctionSymbol.resolvedReturnType.type,
+                context.session
+            )
+        ) {
+            @Suppress("UNCHECKED_CAST")
+            reporter.reportOn(
+                callableDeclaration.source,
+                FirErrors.ACTUAL_WITHOUT_EXPECT,
+                actualFunctionSymbol,
+                actualFunctionSymbol.expectForActual as Map<ExpectActualCompatibility.Incompatible<FirBasedSymbol<*>>, Collection<FirBasedSymbol<*>>>,
+                context
+            )
+        }
+    }
+}

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirActualDeclarationChecker.kt

@@ -1,74 +0,0 @@
-/*
- * Copyright 2010-2023 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.fir.analysis.checkers.declaration
-
-import org.jetbrains.kotlin.diagnostics.DiagnosticReporter
-import org.jetbrains.kotlin.diagnostics.reportOn
-import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
-import org.jetbrains.kotlin.fir.analysis.checkers.getContainingClassSymbol
-import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors
-import org.jetbrains.kotlin.fir.declarations.*
-import org.jetbrains.kotlin.fir.declarations.utils.isActual
-import org.jetbrains.kotlin.fir.symbols.FirBasedSymbol
-import org.jetbrains.kotlin.fir.symbols.impl.FirCallableSymbol
-import org.jetbrains.kotlin.fir.types.*
-import org.jetbrains.kotlin.resolve.multiplatform.ExpectActualCompatibility
-
-object FirActualDeclarationChecker : FirBasicDeclarationChecker() {
-    override fun check(declaration: FirDeclaration, context: CheckerContext, reporter: DiagnosticReporter) {
-        if (declaration !is FirMemberDeclaration || !declaration.isActual) return
-
-        if (declaration is FirCallableDeclaration) {
-            if (declaration is FirFunction) {
-                checkActualFunctionWithDefaultArguments(declaration, reporter, context)
-            }
-            checkReturnTypes(declaration, context, reporter)
-        }
-    }
-
-    private fun checkActualFunctionWithDefaultArguments(function: FirFunction, reporter: DiagnosticReporter, context: CheckerContext) {
-        for (valueParameter in function.valueParameters) {
-            if (valueParameter.defaultValue != null) {
-                reporter.reportOn(valueParameter.source, FirErrors.ACTUAL_FUNCTION_WITH_DEFAULT_ARGUMENTS, context)
-            }
-        }
-    }
-
-    private fun checkReturnTypes(callableDeclaration: FirCallableDeclaration, context: CheckerContext, reporter: DiagnosticReporter) {
-        val actualFunctionSymbol = callableDeclaration.symbol
-        val expectFunctionSymbol = actualFunctionSymbol.getSingleCompatibleExpectForActualOrNull() as? FirCallableSymbol ?: return
-
-        val expectTypeParameters = expectFunctionSymbol.getContainingClassSymbol(expectFunctionSymbol.moduleData.session)
-            ?.typeParameterSymbols.orEmpty()
-        val actualClassTypeParameters = actualFunctionSymbol.getContainingClassSymbol(context.session)?.typeParameterSymbols.orEmpty()
-        val parentSubstitutor =
-            createExpectActualTypeParameterSubstitutor(expectTypeParameters, actualClassTypeParameters, context.session)
-
-        val substitutor = createExpectActualTypeParameterSubstitutor(
-            expectFunctionSymbol.typeParameterSymbols,
-            actualFunctionSymbol.typeParameterSymbols,
-            context.session,
-            parentSubstitutor
-        )
-
-        if (!areCompatibleExpectActualTypes(
-                substitutor.substituteOrSelf(expectFunctionSymbol.resolvedReturnType.type),
-                actualFunctionSymbol.resolvedReturnType.type,
-                expectFunctionSymbol.moduleData.session,
-                context.session
-            )
-        ) {
-            @Suppress("UNCHECKED_CAST")
-            reporter.reportOn(
-                callableDeclaration.source,
-                FirErrors.ACTUAL_WITHOUT_EXPECT,
-                actualFunctionSymbol,
-                actualFunctionSymbol.expectForActual as Map<ExpectActualCompatibility.Incompatible<FirBasedSymbol<*>>, Collection<FirBasedSymbol<*>>>,
-                context
-            )
-        }
-    }
-}

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirActualTypeAliasChecker.kt

@@ -0,0 +1,33 @@
+/*
+ * Copyright 2010-2023 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.fir.analysis.checkers.declaration
+
+import org.jetbrains.kotlin.diagnostics.DiagnosticReporter
+import org.jetbrains.kotlin.diagnostics.reportOn
+import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
+import org.jetbrains.kotlin.fir.analysis.checkers.toClassLikeSymbol
+import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors
+import org.jetbrains.kotlin.fir.declarations.FirTypeAlias
+import org.jetbrains.kotlin.fir.declarations.utils.isActual
+import org.jetbrains.kotlin.fir.symbols.impl.FirTypeAliasSymbol
+
+object FirActualTypeAliasChecker : FirTypeAliasChecker() {
+    override fun check(declaration: FirTypeAlias, context: CheckerContext, reporter: DiagnosticReporter) {
+        if (!declaration.isActual) return
+
+        checkActualTypeAliasNotToClass(declaration, context, reporter)
+    }
+
+    private fun checkActualTypeAliasNotToClass(
+        declaration: FirTypeAlias,
+        context: CheckerContext,
+        reporter: DiagnosticReporter
+    ) {
+        if (declaration.expandedTypeRef.toClassLikeSymbol(context.session) is FirTypeAliasSymbol) {
+            reporter.reportOn(declaration.source, FirErrors.ACTUAL_TYPE_ALIAS_NOT_TO_CLASS, context)
+        }
+    }
+}

compiler/testData/diagnostics/tests/multiplatform/headerClass/genericClassImplTypeAlias.fir.kt

@@ -27,4 +27,4 @@ actual typealias C8<J> = MutableList<*>
 actual typealias C9<K> = MutableList<in K>
 
 typealias Tmp<K> = MutableList<K>
-actual typealias C10<L> = Tmp<L>
+<!ACTUAL_TYPE_ALIAS_NOT_TO_CLASS!>actual typealias C10<L> = Tmp<L><!>