FIR: Fix exception caused by empty supertypes of java.lang.Object

analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/DiagnosisCompilerFirTestdataTestGenerated.java

@@ -5396,6 +5396,12 @@ public class DiagnosisCompilerFirTestdataTestGenerated extends AbstractDiagnosis
             public void testTypeParameterUse() throws Exception {
                 runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/j+k/typeParameterUse.kt");
             }
+
+            @Test
+            @TestMetadata("UsingObject.kt")
+            public void testUsingObject() throws Exception {
+                runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/j+k/UsingObject.kt");
+            }
         }
 
         @Nested

compiler/fir/analysis-tests/testData/resolveWithStdlib/j+k/UsingObject.fir.txt

@@ -0,0 +1,14 @@
+FILE: UsingObject.kt
+    public final class A : R|kotlin/Any| {
+        public constructor(): R|A| {
+            super<R|kotlin/Any|>()
+        }
+
+    }
+    public final fun foo(): R|A?| {
+        ^foo Null(null)
+    }
+    public final fun main(): R|kotlin/Unit| {
+        lval w: R|kotlin/Any| = R|/foo|() ?: Q|java/lang|.R|java/lang/Object.Object|()
+        R|<local>/w|.R|kotlin/Any.hashCode|()
+    }

compiler/fir/analysis-tests/testData/resolveWithStdlib/j+k/UsingObject.kt

@@ -0,0 +1,8 @@
+class A
+
+fun foo(): A? = null
+
+fun main() {
+    val w = foo() ?: java.lang.Object()
+    w.hashCode()
+}

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

@@ -5396,6 +5396,12 @@ public class FirDiagnosticTestGenerated extends AbstractFirDiagnosticTest {
             public void testTypeParameterUse() throws Exception {
                 runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/j+k/typeParameterUse.kt");
             }
+
+            @Test
+            @TestMetadata("UsingObject.kt")
+            public void testUsingObject() throws Exception {
+                runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/j+k/UsingObject.kt");
+            }
         }
 
         @Nested

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

@@ -5396,6 +5396,12 @@ public class FirDiagnosticsWithLightTreeTestGenerated extends AbstractFirDiagnos
             public void testTypeParameterUse() throws Exception {
                 runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/j+k/typeParameterUse.kt");
             }
+
+            @Test
+            @TestMetadata("UsingObject.kt")
+            public void testUsingObject() throws Exception {
+                runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/j+k/UsingObject.kt");
+            }
         }
 
         @Nested

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/FirJavaFacade.kt

@@ -33,15 +33,13 @@ import org.jetbrains.kotlin.fir.types.ConeClassLikeType
 import org.jetbrains.kotlin.fir.types.ConeFlexibleType
 import org.jetbrains.kotlin.fir.types.ConeKotlinType
 import org.jetbrains.kotlin.fir.types.builder.buildResolvedTypeRef
+import org.jetbrains.kotlin.fir.types.constructClassLikeType
 import org.jetbrains.kotlin.fir.types.impl.ConeTypeParameterTypeImpl
 import org.jetbrains.kotlin.load.java.JavaClassFinder
 import org.jetbrains.kotlin.load.java.JvmAnnotationNames
 import org.jetbrains.kotlin.load.java.structure.*
 import org.jetbrains.kotlin.load.java.structure.impl.JavaElementImpl
-import org.jetbrains.kotlin.name.CallableId
-import org.jetbrains.kotlin.name.ClassId
-import org.jetbrains.kotlin.name.FqName
-import org.jetbrains.kotlin.name.Name
+import org.jetbrains.kotlin.name.*
 import org.jetbrains.kotlin.types.Variance.INVARIANT
 import org.jetbrains.kotlin.util.OperatorNameConventions
 
@@ -195,6 +193,13 @@ class FirJavaFacade(
                 }
             }
             javaClass.supertypes.mapTo(superTypeRefs) { it.toFirJavaTypeRef(session, javaTypeParameterStack) }
+            if (superTypeRefs.isEmpty()) {
+                superTypeRefs.add(
+                    buildResolvedTypeRef {
+                        type = StandardClassIds.Any.constructClassLikeType(emptyArray(), isNullable = false)
+                    }
+                )
+            }
 
             val dispatchReceiver = classId.defaultType(typeParameters.map { it.symbol })