FIR: use default getter in serializer if fir contains none

since we generate the default getter in this case in
Fir2IrDeclarationStorage.createIrProperty, so the serialized metadata
should follow the same behavior.
#KT-57373 fixed

compiler/fir/fir-serialization/src/org/jetbrains/kotlin/fir/serialization/FirElementSerializer.kt

@@ -18,6 +18,8 @@ import org.jetbrains.kotlin.fir.*
 import org.jetbrains.kotlin.fir.declarations.*
 import org.jetbrains.kotlin.fir.declarations.comparators.FirCallableDeclarationComparator
 import org.jetbrains.kotlin.fir.declarations.impl.FirDefaultPropertyAccessor
+import org.jetbrains.kotlin.fir.declarations.impl.FirDefaultPropertyGetter
+import org.jetbrains.kotlin.fir.declarations.impl.FirDefaultPropertySetter
 import org.jetbrains.kotlin.fir.declarations.utils.*
 import org.jetbrains.kotlin.fir.deserialization.projection
 import org.jetbrains.kotlin.fir.expressions.*
@@ -341,7 +343,14 @@ class FirElementSerializer private constructor(
             false, false, false
         )
 
-        val getter = property.getter
+        val getter = property.getter ?: with(property) {
+            if (origin == FirDeclarationOrigin.Delegated) {
+                // since we generate the default accessor on fir2ir anyway (Fir2IrDeclarationStorage.createIrProperty), we have to
+                // serialize it accordingly at least for delegates to fix issues like #KT-57373
+                // TODO: rewrite accordingly after fixing #KT-58233
+                FirDefaultPropertyGetter(source = null, moduleData, origin, returnTypeRef, visibility, symbol)
+            } else null
+        }
         if (getter != null) {
             hasGetter = true
             val accessorFlags = getAccessorFlags(getter, property)
@@ -350,7 +359,14 @@ class FirElementSerializer private constructor(
             }
         }
 
-        val setter = property.setter
+        val setter = property.setter ?: with(property) {
+            if (origin == FirDeclarationOrigin.Delegated && isVar) {
+                // since we generate the default accessor on fir2ir anyway (Fir2IrDeclarationStorage.createIrProperty), we have to
+                // serialize it accordingly at least for delegates to fix issues like #KT-57373
+                // TODO: rewrite accordingly after fixing #KT-58233
+                FirDefaultPropertySetter(source = null, moduleData, origin, returnTypeRef, visibility, symbol)
+            } else null
+        }
         if (setter != null) {
             hasSetter = true
             val accessorFlags = getAccessorFlags(setter, property)

compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirLightTreeBlackBoxCodegenTestGenerated.java

@@ -15709,6 +15709,12 @@ public class FirLightTreeBlackBoxCodegenTestGenerated extends AbstractFirLightTr
             runTest("compiler/testData/codegen/box/delegation/delegationDifferentModule.kt");
         }
 
+        @Test
+        @TestMetadata("delegationDifferentModule2.kt")
+        public void testDelegationDifferentModule2() throws Exception {
+            runTest("compiler/testData/codegen/box/delegation/delegationDifferentModule2.kt");
+        }
+
         @Test
         @TestMetadata("delegationToIntersectionType.kt")
         public void testDelegationToIntersectionType() throws Exception {

compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirPsiBlackBoxCodegenTestGenerated.java

@@ -15709,6 +15709,12 @@ public class FirPsiBlackBoxCodegenTestGenerated extends AbstractFirPsiBlackBoxCo
             runTest("compiler/testData/codegen/box/delegation/delegationDifferentModule.kt");
         }
 
+        @Test
+        @TestMetadata("delegationDifferentModule2.kt")
+        public void testDelegationDifferentModule2() throws Exception {
+            runTest("compiler/testData/codegen/box/delegation/delegationDifferentModule2.kt");
+        }
+
         @Test
         @TestMetadata("delegationToIntersectionType.kt")
         public void testDelegationToIntersectionType() throws Exception {

compiler/testData/codegen/box/delegation/delegationDifferentModule2.kt

@@ -0,0 +1,24 @@
+// MODULE: lib
+// FILE: lib.kt
+
+interface I {
+    val bar: Int
+}
+
+class Impl : I {
+    override val bar: Int = 42
+}
+
+class D1(foo: I) : I by foo
+
+// MODULE: main(lib)
+// FILE: main.kt
+
+class D2(foo: I) : I by foo
+
+fun box() : String {
+    val c = Impl()
+    if (D1(c).bar != 42) return "FAIL 1"
+    if (D2(c).bar != 42) return "FAIL 2"
+    return "OK"
+}

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

@@ -15373,6 +15373,12 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             runTest("compiler/testData/codegen/box/delegation/delegationDifferentModule.kt");
         }
 
+        @Test
+        @TestMetadata("delegationDifferentModule2.kt")
+        public void testDelegationDifferentModule2() throws Exception {
+            runTest("compiler/testData/codegen/box/delegation/delegationDifferentModule2.kt");
+        }
+
         @Test
         @TestMetadata("delegationToIntersectionType.kt")
         public void testDelegationToIntersectionType() throws Exception {

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

@@ -15709,6 +15709,12 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
             runTest("compiler/testData/codegen/box/delegation/delegationDifferentModule.kt");
         }
 
+        @Test
+        @TestMetadata("delegationDifferentModule2.kt")
+        public void testDelegationDifferentModule2() throws Exception {
+            runTest("compiler/testData/codegen/box/delegation/delegationDifferentModule2.kt");
+        }
+
         @Test
         @TestMetadata("delegationToIntersectionType.kt")
         public void testDelegationToIntersectionType() throws Exception {

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

@@ -15709,6 +15709,12 @@ public class IrBlackBoxCodegenWithIrInlinerTestGenerated extends AbstractIrBlack
             runTest("compiler/testData/codegen/box/delegation/delegationDifferentModule.kt");
         }
 
+        @Test
+        @TestMetadata("delegationDifferentModule2.kt")
+        public void testDelegationDifferentModule2() throws Exception {
+            runTest("compiler/testData/codegen/box/delegation/delegationDifferentModule2.kt");
+        }
+
         @Test
         @TestMetadata("delegationToIntersectionType.kt")
         public void testDelegationToIntersectionType() throws Exception {

compiler/tests-gen/org/jetbrains/kotlin/codegen/LightAnalysisModeTestGenerated.java

@@ -12630,6 +12630,11 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
             runTest("compiler/testData/codegen/box/delegation/delegationDifferentModule.kt");
         }
 
+        @TestMetadata("delegationDifferentModule2.kt")
+        public void testDelegationDifferentModule2() throws Exception {
+            runTest("compiler/testData/codegen/box/delegation/delegationDifferentModule2.kt");
+        }
+
         @TestMetadata("delegationToIntersectionType.kt")
         public void testDelegationToIntersectionType() throws Exception {
             runTest("compiler/testData/codegen/box/delegation/delegationToIntersectionType.kt");