[FIR] Don't create generated nested classifier scope for non-source classes

^KT-57626 Fixed

compiler/fir/providers/src/org/jetbrains/kotlin/fir/scopes/impl/FirDeclaredMemberScopeProvider.kt

@@ -91,11 +91,14 @@ class FirDeclaredMemberScopeProvider(val useSiteSession: FirSession) : FirSessio
     }
 
     private fun createNestedClassifierScope(klass: FirClass): FirNestedClassifierScope? {
-        return if (klass.origin.generated) {
+        val origin = klass.origin
+        return if (origin.generated) {
             FirGeneratedClassNestedClassifierScope.create(useSiteSession, klass, baseScope = null)
         } else {
             val baseScope = FirNestedClassifierScopeImpl(klass, useSiteSession)
-            val generatedScope = FirGeneratedClassNestedClassifierScope.create(useSiteSession, klass, baseScope)
+            val generatedScope = runIf(origin.fromSource) {
+                FirGeneratedClassNestedClassifierScope.create(useSiteSession, klass, baseScope)
+            }
             if (generatedScope != null) {
                 FirCompositeNestedClassifierScope(
                     listOf(baseScope, generatedScope),

plugins/kotlinx-serialization/testData/boxIr/serializableFromAnotherModule.kt

@@ -0,0 +1,25 @@
+// TARGET_BACKEND: JVM_IR
+// WITH_STDLIB
+// ISSUE: KT-57626
+
+// MODULE: lib
+import kotlinx.serialization.*
+
+@Serializable
+data class A(val s: String = "")
+
+// MODULE: main(lib)
+import kotlinx.serialization.*
+import kotlinx.serialization.json.*
+
+@Serializable
+data class B(val a: A? = null)
+
+fun box(): String {
+    val expectedB = B(A("OK"))
+    val json = Json.encodeToString(B.serializer(), expectedB)
+    if (json != """{"a":{"s":"OK"}}""") return "Fail: $json"
+    val actualB = Json.decodeFromString(B.serializer(), json)
+    if (expectedB != actualB) return "Fail: $actualB"
+    return "OK"
+}

plugins/kotlinx-serialization/tests-gen/org/jetbrains/kotlinx/serialization/runners/SerializationFirLightTreeBlackBoxTestGenerated.java

@@ -177,6 +177,12 @@ public class SerializationFirLightTreeBlackBoxTestGenerated extends AbstractSeri
             runTest("plugins/kotlinx-serialization/testData/boxIr/serialInfo.kt");
         }
 
+        @Test
+        @TestMetadata("serializableFromAnotherModule.kt")
+        public void testSerializableFromAnotherModule() throws Exception {
+            runTest("plugins/kotlinx-serialization/testData/boxIr/serializableFromAnotherModule.kt");
+        }
+
         @Test
         @TestMetadata("serializableOnPropertyType.kt")
         public void testSerializableOnPropertyType() throws Exception {

plugins/kotlinx-serialization/tests-gen/org/jetbrains/kotlinx/serialization/runners/SerializationIrBoxTestGenerated.java

@@ -175,6 +175,12 @@ public class SerializationIrBoxTestGenerated extends AbstractSerializationIrBoxT
         runTest("plugins/kotlinx-serialization/testData/boxIr/serialInfo.kt");
     }
 
+    @Test
+    @TestMetadata("serializableFromAnotherModule.kt")
+    public void testSerializableFromAnotherModule() throws Exception {
+        runTest("plugins/kotlinx-serialization/testData/boxIr/serializableFromAnotherModule.kt");
+    }
+
     @Test
     @TestMetadata("serializableOnPropertyType.kt")
     public void testSerializableOnPropertyType() throws Exception {