FIR: enhance Java super types

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

@@ -195,27 +195,15 @@ class JavaSymbolProvider(
 
         // There's a bit of an ordering restriction here:
         // 1. annotations should be added after the symbol is bound, as annotations can refer to the class itself;
-        // 2. bound/supertype conversion should happen here for the same reason;
+        // 2. type enhancement requires annotations to be already present (and supertypes can refer to type parameters).
-        // 3. type enhancement requires annotations to be already present (and supertypes can refer to type parameters).
         firJavaClass.annotations.addFromJava(session, javaClass, javaTypeParameterStack)
         val enhancement = FirSignatureEnhancement(firJavaClass, session) { emptyList() }
         enhancement.enhanceTypeParameterBounds(firJavaClass.typeParameters)
-        firJavaClass.convertSuperTypes(javaClass, javaTypeParameterStack)
+        firJavaClass.superTypeRefs.replaceAll { enhancement.enhanceSuperType(it) }
         firJavaClass.replaceDeprecation(firJavaClass.getDeprecationInfos(session.languageVersionSettings.apiVersion))
         return firJavaClass
     }
 
-    private fun FirJavaClass.convertSuperTypes(
-        javaClass: JavaClass,
-        javaTypeParameterStack: JavaTypeParameterStack
-    ) {
-        replaceSuperTypeRefs(
-            javaClass.supertypes.map { supertype ->
-                supertype.toFirResolvedTypeRef(session, javaTypeParameterStack, FirJavaTypeConversionMode.SUPERTYPE)
-            }
-        )
-    }
-
     private fun createFirJavaClass(
         javaClass: JavaClass,
         classSymbol: FirRegularClassSymbol,
@@ -255,6 +243,7 @@ class JavaSymbolProvider(
                     buildOuterClassTypeParameterRef { symbol = it.symbol }
                 }
             }
+            javaClass.supertypes.mapTo(superTypeRefs) { it.toFirJavaTypeRef(session, javaTypeParameterStack) }
 
             val dispatchReceiver = classId.defaultType(typeParameters.map { it.symbol })
 

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/enhancement/SignatureEnhancement.kt

@@ -352,6 +352,12 @@ class FirSignatureEnhancement(
             AnnotationQualifierApplicabilityType.TYPE_PARAMETER_BOUNDS, context.defaultTypeQualifiers
         ).enhance(bound, emptyList(), FirJavaTypeConversionMode.TYPE_PARAMETER_BOUND)
 
+    fun enhanceSuperType(type: FirTypeRef): FirTypeRef =
+        EnhancementSignatureParts(
+            session, typeQualifierResolver, null, isCovariant = false, forceOnlyHeadTypeConstructor = false,
+            AnnotationQualifierApplicabilityType.TYPE_USE, context.defaultTypeQualifiers
+        ).enhance(type, emptyList(), FirJavaTypeConversionMode.SUPERTYPE)
+
     // ================================================================================================
 
     private fun enhanceReceiverType(

compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/strictMode/SelfType.fir.kt

@@ -39,15 +39,18 @@ public class CKN extends C<@Nullable CK> {}
 // FILE: main.kt
 fun main(ak: AK, akn: AKN, bk: BK, ck: CK, ckn: CKN): Unit {
     ak.foo(ak)
-    ak.foo(null)
+    // jspecify_nullness_mismatch
+    ak.foo(<!NULL_FOR_NONNULL_TYPE!>null<!>)
 
     akn.foo(null)
 
     bk.foo(bk)
-    bk.foo(null)
+    // jspecify_nullness_mismatch
+    bk.foo(<!NULL_FOR_NONNULL_TYPE!>null<!>)
 
     ck.foo(ck)
-    ck.foo(null)
+    // jspecify_nullness_mismatch
+    ck.foo(<!NULL_FOR_NONNULL_TYPE!>null<!>)
 
     ckn.foo(null)
 }

compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/jspecify/warnMode/SelfType.fir.kt

@@ -40,15 +40,15 @@ public class CKN extends C<@Nullable CK> {}
 // FILE: main.kt
 fun main(ak: AK, akn: AKN, bk: BK, ck: CK, ckn: CKN): Unit {
     ak.foo(ak)
-    ak.foo(null)
+    ak.foo(<!NULL_FOR_NONNULL_TYPE!>null<!>)
 
     akn.foo(null) // the corresponding warning/error is present on the Java side
 
     bk.foo(bk)
-    bk.foo(null)
+    bk.foo(<!NULL_FOR_NONNULL_TYPE!>null<!>)
 
     ck.foo(ck)
-    ck.foo(null)
+    ck.foo(<!NULL_FOR_NONNULL_TYPE!>null<!>)
 
     ckn.foo(null) // the corresponding warning/error is present on the Java side
 }

compiler/testData/diagnostics/foreignAnnotationsTests/java8Tests/misc/warningsBasedOnEnhancedBasedType.fir.kt

@@ -19,5 +19,5 @@ class Test extends Base<@Nullable String> {}
 fun takeBaseOfNotNullStrings(x: Base<String>) {}
 
 fun main() {
-    val x = takeBaseOfNotNullStrings(Test())
+    val x = takeBaseOfNotNullStrings(<!ARGUMENT_TYPE_MISMATCH!>Test()<!>)
 }