Add check for sealed interfaces

resources/bytecode/javFiles/SwitchRecordList.jav

@@ -3,7 +3,7 @@ import java.lang.Object;
 import java.lang.Float;
 import java.lang.String;
 
-sealed interface List permits LinkedElem {}
+sealed interface List permits LinkedElem, Elem {}
 
 
 public record LinkedElem(Integer a,List l) implements List{} //Implementiert List und wird auch permittet

src/main/java/de/dhbwstuttgart/bytecode/Codegen.java

@@ -1599,6 +1599,16 @@ public class Codegen {
         if (!(clazz instanceof TargetInterface))
             access |= ACC_SUPER;
 
+        // Check sealed
+        for (var intf : clazz.implementingInterfaces()) {
+            var intfClass = compiler.getClass(new JavaClassName(intf.name()));
+            if (intfClass.isSealed()) {
+                if (intfClass.getPermittedSubtypes().stream().noneMatch(type -> type.getName().equals(new JavaClassName(className)))) {
+                    throw new CodeGenException("Sealed interface " + intfClass.getClassName() + " doesn't permit class " + className);
+                }
+            }
+        }
+
         var signature = generateSignature(clazz, clazz.generics());
         var interfaces = clazz.implementingInterfaces().stream().map(TargetType::getInternalName).toArray(String[]::new);
         var superType = clazz.superType() != null ? clazz.superType().getInternalName() : "java/lang/Object";

src/main/java/de/dhbwstuttgart/parser/SyntaxTreeGenerator/SyntaxTreeGenerator.java

@@ -393,12 +393,12 @@ public class SyntaxTreeGenerator {
     if (!Objects.isNull(ctx.EXTENDS())) {
       extendedInterfaces.addAll(convert(ctx.typeList(0), generics));
     }
-    List<RefType> permittedSubtypes = new ArrayList<>();
+    List<RefType> permittedSubtypes = null;
     // Ist Bit für 'sealed'-Modifier gesetzt
     if ((modifiers & 4096) != 0) {
       if (!Objects.isNull(ctx.PERMITS())) {
         // permitted subtypes sind letzte typeList (siehe Grammatikregel 'classDeclaration')
-        permittedSubtypes.addAll(convert(ctx.typeList(ctx.typeList().size() - 1), generics));
+        permittedSubtypes = new ArrayList<>(convert(ctx.typeList(ctx.typeList().size() - 1), generics));
       } else {
         // falls sealed modifier ohne 'permits'-List oder umgekehrt
         throw new NotImplementedException("Invalid sealed class declaration");

src/main/java/de/dhbwstuttgart/syntaxtree/ClassOrInterface.java

@@ -86,6 +86,9 @@ public class ClassOrInterface extends SyntaxTreeNode implements TypeScope {
     return staticInitializer;
   }
 
+  public boolean isSealed() { return permittedSubtypes != null; }
+  public List<RefType> getPermittedSubtypes() { return permittedSubtypes != null ? permittedSubtypes : List.of(); }
+
   public boolean isInterface() {
       return (Modifier.INTERFACE & this.getModifiers()) != 0;
   }