FIR: report SMARTCAST_IMPOSSIBLE on inherited alien properties [KT-48101]

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

@@ -28058,6 +28058,12 @@ public class FirOldFrontendDiagnosticsTestGenerated extends AbstractFirDiagnosti
                     runTest("compiler/testData/diagnostics/tests/smartCasts/publicVals/otherModule.kt");
                 }
 
+                @Test
+                @TestMetadata("otherModuleInheritance.kt")
+                public void testOtherModuleInheritance() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/smartCasts/publicVals/otherModuleInheritance.kt");
+                }
+
                 @Test
                 @TestMetadata("protected.kt")
                 public void testProtected() throws Exception {

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

@@ -28058,6 +28058,12 @@ public class FirOldFrontendDiagnosticsWithLightTreeTestGenerated extends Abstrac
                     runTest("compiler/testData/diagnostics/tests/smartCasts/publicVals/otherModule.kt");
                 }
 
+                @Test
+                @TestMetadata("otherModuleInheritance.kt")
+                public void testOtherModuleInheritance() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/smartCasts/publicVals/otherModuleInheritance.kt");
+                }
+
                 @Test
                 @TestMetadata("protected.kt")
                 public void testProtected() throws Exception {

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/dfa/VariableStorage.kt

@@ -15,6 +15,8 @@ import org.jetbrains.kotlin.fir.declarations.impl.FirDefaultPropertyAccessor
 import org.jetbrains.kotlin.fir.declarations.utils.modality
 import org.jetbrains.kotlin.fir.expressions.*
 import org.jetbrains.kotlin.fir.expressions.impl.FirNoReceiverExpression
+import org.jetbrains.kotlin.fir.originalIfFakeOverride
+import org.jetbrains.kotlin.fir.originalOrSelf
 import org.jetbrains.kotlin.fir.references.FirThisReference
 import org.jetbrains.kotlin.fir.resolve.fullyExpandedType
 import org.jetbrains.kotlin.fir.resolve.toSymbol
@@ -184,7 +186,7 @@ class VariableStorage(private val session: FirSession) {
             property.isVar -> PropertyStability.MUTABLE_PROPERTY
             property.receiverTypeRef != null -> PropertyStability.PROPERTY_WITH_GETTER
             property.getter.let { it != null && it !is FirDefaultPropertyAccessor } -> PropertyStability.PROPERTY_WITH_GETTER
-            property.moduleData.session != session -> PropertyStability.ALIEN_PUBLIC_PROPERTY
+            property.originalOrSelf().moduleData.session != session -> PropertyStability.ALIEN_PUBLIC_PROPERTY
             property.modality != Modality.FINAL -> {
                 val dispatchReceiver = (originalFir.unwrapElement() as? FirQualifiedAccess)?.dispatchReceiver ?: return null
                 val receiverType = dispatchReceiver.typeRef.coneTypeSafe<ConeClassLikeType>()?.fullyExpandedType(session) ?: return null

compiler/testData/diagnostics/tests/smartCasts/publicVals/otherModuleInheritance.fir.kt

@@ -0,0 +1,25 @@
+// MODULE: m1
+// FILE: A.kt
+
+open class Base(val x: Any)
+open class Generic<T>(val y: T)
+
+// MODULE: m2(m1)
+// FILE: B.kt
+
+class Derived : Base("123") {
+    fun foo() {
+        if (x is String) {
+            <!SMARTCAST_IMPOSSIBLE!>x<!>.length // impossible since `x` is in another module. FE1.0 allows this due to KT-47225
+        }
+    }
+}
+
+class MyGeneric : Generic<Number>(42) {
+    private fun baz(arg: Int) {}
+    fun bar() {
+        if (y is Int) {
+            baz(<!SMARTCAST_IMPOSSIBLE!>y<!>) // impossible since `y` is in another module. FE1.0 allows this due to KT-47225
+        }
+    }
+}

compiler/testData/diagnostics/tests/smartCasts/publicVals/otherModuleInheritance.kt

@@ -0,0 +1,25 @@
+// MODULE: m1
+// FILE: A.kt
+
+open class Base(val x: Any)
+open class Generic<T>(val y: T)
+
+// MODULE: m2(m1)
+// FILE: B.kt
+
+class Derived : Base("123") {
+    fun foo() {
+        if (x is String) {
+            <!DEBUG_INFO_SMARTCAST!>x<!>.length // impossible since `x` is in another module. FE1.0 allows this due to KT-47225
+        }
+    }
+}
+
+class MyGeneric : Generic<Number>(42) {
+    private fun baz(arg: Int) {}
+    fun bar() {
+        if (y is Int) {
+            baz(<!DEBUG_INFO_SMARTCAST!>y<!>) // impossible since `y` is in another module. FE1.0 allows this due to KT-47225
+        }
+    }
+}

compiler/testData/diagnostics/tests/smartCasts/publicVals/otherModuleInheritance.txt

@@ -0,0 +1,40 @@
+// -- Module: <m1> --
+package
+
+public open class Base {
+    public constructor Base(/*0*/ x: kotlin.Any)
+    public final val x: kotlin.Any
+    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 open class Generic</*0*/ T> {
+    public constructor Generic</*0*/ T>(/*0*/ y: T)
+    public final val y: 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
+}
+
+// -- Module: <m2> --
+package
+
+public final class Derived : Base {
+    public constructor Derived()
+    public final override /*1*/ /*fake_override*/ val x: kotlin.Any
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public final fun foo(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final class MyGeneric : Generic<kotlin.Number> {
+    public constructor MyGeneric()
+    public final override /*1*/ /*fake_override*/ val y: kotlin.Number
+    public final fun bar(): kotlin.Unit
+    private final fun baz(/*0*/ arg: kotlin.Int): kotlin.Unit
+    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/regression/kt10001.fir.kt

@@ -1,9 +0,0 @@
-fun foo1(p: Pair<Int?, Int>): Int {
-    if (p.first != null) return p.first<!UNNECESSARY_NOT_NULL_ASSERTION!>!!<!>
-    return p.second
-}
-
-fun foo2(p: Pair<Int?, Int>): Int {
-    if (p.first != null) return p.first
-    return p.second
-}

compiler/testData/diagnostics/testsWithStdLib/regression/kt10001.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 fun foo1(p: Pair<Int?, Int>): Int {
     if (p.first != null) return p.first!!
     return p.second

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

@@ -28148,6 +28148,12 @@ public class DiagnosticTestGenerated extends AbstractDiagnosticTest {
                     runTest("compiler/testData/diagnostics/tests/smartCasts/publicVals/otherModule.kt");
                 }
 
+                @Test
+                @TestMetadata("otherModuleInheritance.kt")
+                public void testOtherModuleInheritance() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/smartCasts/publicVals/otherModuleInheritance.kt");
+                }
+
                 @Test
                 @TestMetadata("protected.kt")
                 public void testProtected() throws Exception {

compiler/tests-spec/testData/diagnostics/notLinked/dfa/neg/40.fir.kt

@@ -9,7 +9,7 @@
 fun case_1(x: Pair<*, *>) {
     if (x.first !is String) return
     x.first
-    x.first.length
+    <!SMARTCAST_IMPOSSIBLE!>x.first<!>.length
 }
 
 /*
@@ -19,5 +19,5 @@ fun case_1(x: Pair<*, *>) {
 fun case_2(x: Pair<*, *>) {
     if (x.first !is String?) throw Exception()
     x.first
-    x.first?.length
+    x.first?.<!UNRESOLVED_REFERENCE!>length<!>
 }

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

@@ -28058,6 +28058,12 @@ public class DiagnosisCompilerTestFE10TestdataTestGenerated extends AbstractDiag
                     runTest("compiler/testData/diagnostics/tests/smartCasts/publicVals/otherModule.kt");
                 }
 
+                @Test
+                @TestMetadata("otherModuleInheritance.kt")
+                public void testOtherModuleInheritance() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/smartCasts/publicVals/otherModuleInheritance.kt");
+                }
+
                 @Test
                 @TestMetadata("protected.kt")
                 public void testProtected() throws Exception {