[FIR] Check classes for EXPECTED_PRIVATE_DECLARATION

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

@@ -8,7 +8,6 @@ package org.jetbrains.kotlin.fir.analysis.checkers
 import org.jetbrains.kotlin.fir.analysis.cfa.AbstractFirPropertyInitializationChecker
 import org.jetbrains.kotlin.fir.analysis.cfa.FirCallsEffectAnalyzer
 import org.jetbrains.kotlin.fir.analysis.cfa.FirPropertyInitializationAnalyzer
-import org.jetbrains.kotlin.fir.analysis.cfa.FirReturnsImpliesAnalyzer
 import org.jetbrains.kotlin.fir.analysis.checkers.cfa.FirControlFlowChecker
 import org.jetbrains.kotlin.fir.analysis.checkers.declaration.*
 import org.jetbrains.kotlin.fir.analysis.checkers.expression.FirAnonymousFunctionParametersChecker
@@ -32,6 +31,7 @@ object CommonDeclarationCheckers : DeclarationCheckers() {
             FirAnnotationChecker,
             FirPublishedApiChecker,
             FirOptInMarkedDeclarationChecker,
+            FirExpectConsistencyChecker,
         )
 
     override val callableDeclarationCheckers: Set<FirCallableDeclarationChecker>

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

@@ -0,0 +1,45 @@
+/*
+ * 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.fir.analysis.checkers.declaration
+
+import org.jetbrains.kotlin.KtFakeSourceElementKind
+import org.jetbrains.kotlin.descriptors.Visibilities
+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.diagnostics.FirErrors
+import org.jetbrains.kotlin.fir.declarations.*
+import org.jetbrains.kotlin.fir.declarations.utils.hasBody
+import org.jetbrains.kotlin.fir.declarations.utils.isExpect
+import org.jetbrains.kotlin.fir.declarations.utils.visibility
+
+// See old FE's [DeclarationsChecker]
+object FirExpectConsistencyChecker : FirBasicDeclarationChecker() {
+    override fun check(declaration: FirDeclaration, context: CheckerContext, reporter: DiagnosticReporter) {
+        val isTopLevel = context.containingDeclarations.size == 1
+        val isInsideClass = context.containingDeclarations.lastOrNull() is FirClass
+
+        if (
+            declaration !is FirMemberDeclaration ||
+            !isTopLevel && !isInsideClass ||
+            !declaration.isExpect ||
+            declaration is FirConstructor
+        ) {
+            return
+        }
+
+        val source = declaration.source ?: return
+        if (source.kind is KtFakeSourceElementKind) return
+
+        if (Visibilities.isPrivate(declaration.visibility)) {
+            reporter.reportOn(source, FirErrors.EXPECTED_PRIVATE_DECLARATION, context)
+        }
+
+        if (declaration is FirSimpleFunction && declaration.hasBody) {
+            reporter.reportOn(source, FirErrors.EXPECTED_DECLARATION_WITH_BODY, context)
+        }
+    }
+}

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

@@ -70,7 +70,5 @@ object FirMemberFunctionsChecker : FirSimpleFunctionChecker() {
                 reporter.reportOn(source, FirErrors.NON_ABSTRACT_FUNCTION_WITH_NO_BODY, functionSymbol, context)
             }
         }
-
-        checkExpectDeclarationVisibilityAndBody(function, source, reporter, context)
     }
 }

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

@@ -79,7 +79,6 @@ object FirMemberPropertiesChecker : FirClassChecker() {
             context,
             reachable
         )
-        checkExpectDeclarationVisibilityAndBody(property, source, reporter, context)
 
         val hasAbstractModifier = KtTokens.ABSTRACT_KEYWORD in modifierList
         val isAbstract = property.isAbstract || hasAbstractModifier

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

@@ -29,8 +29,6 @@ object FirTopLevelFunctionsChecker : FirSimpleFunctionChecker() {
 
         val source = declaration.source ?: return
         if (source.kind is KtFakeSourceElementKind) return
-        // If multiple (potentially conflicting) modality modifiers are specified, not all modifiers are recorded at `status`.
-        // So, our source of truth should be the full modifier list retrieved from the source.
         if (declaration.hasModifier(KtTokens.ABSTRACT_KEYWORD)) return
         if (declaration.isExternal) return
         if (!declaration.hasBody &&
@@ -39,7 +37,5 @@ object FirTopLevelFunctionsChecker : FirSimpleFunctionChecker() {
         ) {
             reporter.reportOn(source, FirErrors.NON_MEMBER_FUNCTION_NO_BODY, declaration.symbol, context)
         }
-
-        checkExpectDeclarationVisibilityAndBody(declaration, source, reporter, context)
     }
 }

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

@@ -46,24 +46,6 @@ object FirTopLevelPropertiesChecker : FirPropertyChecker() {
             reporter,
             context
         )
-        checkExpectDeclarationVisibilityAndBody(declaration, source, reporter, context)
-    }
-}
-
-// TODO: check class too
-internal fun checkExpectDeclarationVisibilityAndBody(
-    declaration: FirMemberDeclaration,
-    source: KtSourceElement,
-    reporter: DiagnosticReporter,
-    context: CheckerContext
-) {
-    if (declaration.isExpect) {
-        if (Visibilities.isPrivate(declaration.visibility)) {
-            reporter.reportOn(source, FirErrors.EXPECTED_PRIVATE_DECLARATION, context)
-        }
-        if (declaration is FirSimpleFunction && declaration.hasBody) {
-            reporter.reportOn(source, FirErrors.EXPECTED_DECLARATION_WITH_BODY, context)
-        }
     }
 }
 

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

@@ -6,7 +6,7 @@ expect class A {
     <!EXPECTED_PRIVATE_DECLARATION!>private<!> val bar: String
     <!EXPECTED_PRIVATE_DECLARATION!>private<!> fun Int.memExt(): Any
 
-    private class Nested
+    <!EXPECTED_PRIVATE_DECLARATION!>private<!> class Nested
 }
 
 // MODULE: m1-jvm()()(m1-common)

compiler/testData/diagnostics/tests/multiplatform/privateTopLevelDeclarations.fir.kt

@@ -5,7 +5,7 @@
 <!EXPECTED_PRIVATE_DECLARATION!>private<!> expect val bar: String
 <!EXPECTED_PRIVATE_DECLARATION!>private<!> expect fun Int.memExt(): Any
 
-private expect class Foo
+<!EXPECTED_PRIVATE_DECLARATION!>private<!> expect class Foo
 
 // MODULE: m2-jvm()()(m1-common)
 // FILE: jvm.kt