Make hierarchy in KSP API sealed

api/api.base

@@ -141,7 +141,7 @@ package com.google.devtools.ksp.processing {
     property @NonNull public abstract String targetName;
   }
 
-  public interface PlatformInfo {
+  public sealed interface PlatformInfo {
     method @NonNull public String getPlatformName();
     property @NonNull public abstract String platformName;
   }
@@ -262,7 +262,7 @@ package com.google.devtools.ksp.symbol {
     enum_constant public static final com.google.devtools.ksp.symbol.FunctionKind TOP_LEVEL;
   }
 
-  public interface KSAnnotated extends com.google.devtools.ksp.symbol.KSNode {
+  public sealed interface KSAnnotated extends com.google.devtools.ksp.symbol.KSNode {
     method @NonNull public kotlin.sequences.Sequence<com.google.devtools.ksp.symbol.KSAnnotation> getAnnotations();
     property @NonNull public abstract kotlin.sequences.Sequence<com.google.devtools.ksp.symbol.KSAnnotation> annotations;
   }
@@ -313,7 +313,7 @@ package com.google.devtools.ksp.symbol {
     property @Nullable public abstract com.google.devtools.ksp.symbol.KSClassifierReference qualifier;
   }
 
-  public interface KSDeclaration extends com.google.devtools.ksp.symbol.KSModifierListOwner com.google.devtools.ksp.symbol.KSAnnotated com.google.devtools.ksp.symbol.KSExpectActual {
+  public sealed interface KSDeclaration extends com.google.devtools.ksp.symbol.KSModifierListOwner com.google.devtools.ksp.symbol.KSAnnotated com.google.devtools.ksp.symbol.KSExpectActual {
     method @Nullable public com.google.devtools.ksp.symbol.KSFile getContainingFile();
     method @Nullable public String getDocString();
     method @NonNull public com.google.devtools.ksp.symbol.KSName getPackageName();
@@ -330,7 +330,7 @@ package com.google.devtools.ksp.symbol {
     property @NonNull public abstract java.util.List<com.google.devtools.ksp.symbol.KSTypeParameter> typeParameters;
   }
 
-  public interface KSDeclarationContainer extends com.google.devtools.ksp.symbol.KSNode {
+  public sealed interface KSDeclarationContainer extends com.google.devtools.ksp.symbol.KSNode {
     method @NonNull public kotlin.sequences.Sequence<com.google.devtools.ksp.symbol.KSDeclaration> getDeclarations();
     property @NonNull public abstract kotlin.sequences.Sequence<com.google.devtools.ksp.symbol.KSDeclaration> declarations;
   }
@@ -390,7 +390,7 @@ package com.google.devtools.ksp.symbol {
     property @Nullable public abstract com.google.devtools.ksp.symbol.KSTypeReference returnType;
   }
 
-  public interface KSModifierListOwner extends com.google.devtools.ksp.symbol.KSNode {
+  public sealed interface KSModifierListOwner extends com.google.devtools.ksp.symbol.KSNode {
     method @NonNull public java.util.Set<com.google.devtools.ksp.symbol.Modifier> getModifiers();
     property @NonNull public abstract java.util.Set<com.google.devtools.ksp.symbol.Modifier> modifiers;
   }
@@ -401,7 +401,7 @@ package com.google.devtools.ksp.symbol {
     method @NonNull public String getShortName();
   }
 
-  public interface KSNode {
+  public sealed interface KSNode {
     method public <D, R> R accept(@NonNull com.google.devtools.ksp.symbol.KSVisitor<D,R> visitor, D data);
     method @NonNull public com.google.devtools.ksp.symbol.Location getLocation();
     method @NonNull public com.google.devtools.ksp.symbol.Origin getOrigin();
@@ -416,7 +416,7 @@ package com.google.devtools.ksp.symbol {
     property @NonNull public abstract com.google.devtools.ksp.symbol.KSReferenceElement element;
   }
 
-  public interface KSPropertyAccessor extends com.google.devtools.ksp.symbol.KSDeclarationContainer com.google.devtools.ksp.symbol.KSAnnotated com.google.devtools.ksp.symbol.KSModifierListOwner {
+  public sealed interface KSPropertyAccessor extends com.google.devtools.ksp.symbol.KSDeclarationContainer com.google.devtools.ksp.symbol.KSAnnotated com.google.devtools.ksp.symbol.KSModifierListOwner {
     method @NonNull public com.google.devtools.ksp.symbol.KSPropertyDeclaration getReceiver();
     property @NonNull public abstract com.google.devtools.ksp.symbol.KSPropertyDeclaration receiver;
   }
@@ -449,7 +449,7 @@ package com.google.devtools.ksp.symbol {
     property @NonNull public abstract com.google.devtools.ksp.symbol.KSValueParameter parameter;
   }
 
-  public interface KSReferenceElement extends com.google.devtools.ksp.symbol.KSNode {
+  public sealed interface KSReferenceElement extends com.google.devtools.ksp.symbol.KSNode {
     method @NonNull public java.util.List<com.google.devtools.ksp.symbol.KSTypeArgument> getTypeArguments();
     property @NonNull public abstract java.util.List<com.google.devtools.ksp.symbol.KSTypeArgument> typeArguments;
   }

api/src/main/kotlin/com/google/devtools/ksp/processing/PlatformInfo.kt

@@ -20,7 +20,7 @@ package com.google.devtools.ksp.processing
 /**
  * Platform specific information
  */
-interface PlatformInfo {
+sealed interface PlatformInfo {
     val platformName: String
 }
 

api/src/main/kotlin/com/google/devtools/ksp/symbol/KSAnnotated.kt

@@ -19,7 +19,7 @@ package com.google.devtools.ksp.symbol
 /**
  * A symbol that can be annotated with annotations.
  */
-interface KSAnnotated : KSNode {
+sealed interface KSAnnotated : KSNode {
 
     /**
      * All annotations on this symbol.

api/src/main/kotlin/com/google/devtools/ksp/symbol/KSDeclaration.kt

@@ -19,7 +19,7 @@ package com.google.devtools.ksp.symbol
 /**
  * A declaration, can be function declaration, class declaration and property declaration, or a type alias.
  */
-interface KSDeclaration : KSModifierListOwner, KSAnnotated, KSExpectActual {
+sealed interface KSDeclaration : KSModifierListOwner, KSAnnotated, KSExpectActual {
     /**
      * Simple name of this declaration, usually the name identifier at the declaration site.
      */

api/src/main/kotlin/com/google/devtools/ksp/symbol/KSDeclarationContainer.kt

@@ -19,7 +19,7 @@ package com.google.devtools.ksp.symbol
 /**
  * A declaration container can have a list of declarations declared in it.
  */
-interface KSDeclarationContainer : KSNode {
+sealed interface KSDeclarationContainer : KSNode {
     /**
      * Declarations that are lexically declared inside the current container.
      */

api/src/main/kotlin/com/google/devtools/ksp/symbol/KSModifierListOwner.kt

@@ -19,7 +19,7 @@ package com.google.devtools.ksp.symbol
 /**
  * A [KSModifierListOwner] can have zero or more modifiers.
  */
-interface KSModifierListOwner : KSNode {
+sealed interface KSModifierListOwner : KSNode {
     /**
      * The set of modifiers on this element.
      */

api/src/main/kotlin/com/google/devtools/ksp/symbol/KSNode.kt

@@ -19,7 +19,7 @@ package com.google.devtools.ksp.symbol
 /**
  * Base class of every visitable program elements.
  */
-interface KSNode {
+sealed interface KSNode {
     val origin: Origin
     val location: Location
     val parent: KSNode?

api/src/main/kotlin/com/google/devtools/ksp/symbol/KSPropertyAccessor.kt

@@ -21,7 +21,7 @@ package com.google.devtools.ksp.symbol
  * Note that annotation use-site targets such as @get: @set: is not copied to accessor's annotations attribute.
  * Use KSAnnotated.findAnnotationFromUseSiteTarget() to ensure annotations from parent is obtained.
  */
-interface KSPropertyAccessor : KSDeclarationContainer, KSAnnotated, KSModifierListOwner {
+sealed interface KSPropertyAccessor : KSDeclarationContainer, KSAnnotated, KSModifierListOwner {
     /**
      * The owner of the property accessor.
      */

api/src/main/kotlin/com/google/devtools/ksp/symbol/KSReferenceElement.kt

@@ -21,7 +21,7 @@ package com.google.devtools.ksp.symbol
  *
  * KSReferenceElement can specify, for example, a class, interface, or function, etc.
  */
-interface KSReferenceElement : KSNode {
+sealed interface KSReferenceElement : KSNode {
     /**
      * Type arguments in the type reference.
      */

compiler-plugin/src/main/kotlin/com/google/devtools/ksp/Incremental.kt

@@ -657,6 +657,8 @@ class IncrementalContext(
         when (declaration) {
             is KSPropertyDeclarationJavaImpl -> recordLookupForJavaField(declaration.psi)
             is KSFunctionDeclarationJavaImpl -> recordLookupForJavaMethod(declaration.psi)
+            is KSClassDeclaration, is KSFunctionDeclaration, is KSPropertyDeclaration, is KSTypeAlias,
+            is KSTypeParameter -> Unit
         }
     }
 

compiler-plugin/src/main/kotlin/com/google/devtools/ksp/processing/impl/ResolverImpl.kt

@@ -627,6 +627,11 @@ class ResolverImpl(
                     resolverContext = resolverContext
                         .childForClassOrPackage(resolveJavaDeclaration(e.psi) as ClassDescriptor, JavaClassImpl(e.psi))
                 }
+                is KSClassDeclaration, is KSFunctionDeclaration, is KSPropertyDeclaration, is KSTypeAlias,
+                is KSTypeParameter, is KSFile, is KSPropertyGetter, is KSPropertySetter, is KSTypeArgument,
+                is KSTypeReference, is KSValueArgument, is KSValueParameter, is KSAnnotation, is KSCallableReference,
+                is KSClassifierReference, is KSDefNonNullReference, is KSDynamicReference, is KSParenthesizedReference,
+                -> Unit
             }
         }
         return if (javaType is JavaArrayTypeImpl)
@@ -1192,6 +1197,7 @@ class ResolverImpl(
                         if (declaration.isAbstract)
                             modifiers.add(Modifier.ABSTRACT)
                     }
+                    is KSTypeAlias, is KSTypeParameter -> Unit
                 }
             }
             Origin.KOTLIN_LIB, Origin.JAVA_LIB -> {
@@ -1208,6 +1214,7 @@ class ResolverImpl(
                         if (declaration.jvmAccessFlag and Opcodes.ACC_SYNCHRONIZED != 0)
                             modifiers.add(Modifier.JAVA_SYNCHRONIZED)
                     }
+                    is KSClassDeclaration, is KSTypeAlias, is KSTypeParameter -> Unit
                 }
             }
             else -> Unit

compiler-plugin/src/main/kotlin/com/google/devtools/ksp/symbol/impl/binary/KSDeclarationDescriptorImpl.kt

@@ -30,21 +30,22 @@ import org.jetbrains.kotlin.resolve.descriptorUtil.parents
 import org.jetbrains.kotlin.resolve.descriptorUtil.parentsWithSelf
 import org.jetbrains.kotlin.utils.addToStdlib.firstIsInstanceOrNull
 
-abstract class KSDeclarationDescriptorImpl(private val descriptor: DeclarationDescriptor) : KSDeclaration {
+abstract class KSDeclarationDescriptorImpl(private val descriptor: DeclarationDescriptor) /*: KSDeclaration*/ {
 
-    override val origin by lazy {
+    open /*override*/ val origin by lazy {
         descriptor.origin
     }
 
-    override val containingFile: KSFile? = null
+    open /*override*/ val containingFile: KSFile? = null
 
-    override val location: Location = NonExistLocation
+    open /*override*/ val location: Location = NonExistLocation
 
-    override val annotations: Sequence<KSAnnotation> by lazy {
-        descriptor.annotations.asSequence().map { KSAnnotationDescriptorImpl.getCached(it, this) }.memoized()
+    open /*override*/ val annotations: Sequence<KSAnnotation> by lazy {
+        descriptor.annotations.asSequence().map { KSAnnotationDescriptorImpl.getCached(it, this as KSDeclaration) }
+            .memoized()
     }
 
-    override val parentDeclaration: KSDeclaration? by lazy {
+    open /*override*/ val parentDeclaration: KSDeclaration? by lazy {
         val containingDescriptor = descriptor.parents.first()
         when (containingDescriptor) {
             is ClassDescriptor -> KSClassDeclarationDescriptorImpl.getCached(containingDescriptor)
@@ -53,27 +54,27 @@ abstract class KSDeclarationDescriptorImpl(private val descriptor: DeclarationDe
         } as KSDeclaration?
     }
 
-    override val parent: KSNode? by lazy {
+    open /*override*/ val parent: KSNode? by lazy {
         parentDeclaration
     }
 
-    override val packageName: KSName by lazy {
+    open /*override*/ val packageName: KSName by lazy {
         KSNameImpl.getCached(descriptor.findPackage().fqName.asString())
     }
 
-    override val qualifiedName: KSName by lazy {
+    open /*override*/ val qualifiedName: KSName by lazy {
         KSNameImpl.getCached(descriptor.fqNameSafe.asString())
     }
 
-    override val simpleName: KSName by lazy {
+    open /*override*/ val simpleName: KSName by lazy {
         KSNameImpl.getCached(descriptor.name.asString())
     }
 
     override fun toString(): String {
         return this.simpleName.asString()
     }
 
-    override val docString = null
+    open /*override*/ val docString: String? = null
 }
 
 val DeclarationDescriptor.origin: Origin

compiler-plugin/src/main/kotlin/com/google/devtools/ksp/symbol/impl/binary/KSPropertyAccessorDescriptorImpl.kt

@@ -25,8 +25,8 @@ import com.google.devtools.ksp.symbol.impl.toKSPropertyDeclaration
 import com.google.devtools.ksp.toKSModifiers
 import org.jetbrains.kotlin.descriptors.PropertyAccessorDescriptor
 
-abstract class KSPropertyAccessorDescriptorImpl(val descriptor: PropertyAccessorDescriptor) : KSPropertyAccessor {
-    override val origin: Origin by lazy {
+abstract class KSPropertyAccessorDescriptorImpl(val descriptor: PropertyAccessorDescriptor) /*: KSPropertyAccessor*/ {
+    open /*override*/ val origin: Origin by lazy {
         when (receiver.origin) {
             // if receiver is kotlin source, that means we are a synthetic where developer
             // didn't declare an explicit accessor so we used the descriptor instead
@@ -35,26 +35,27 @@ abstract class KSPropertyAccessorDescriptorImpl(val descriptor: PropertyAccessor
         }
     }
 
-    override val receiver: KSPropertyDeclaration by lazy {
+    open /*override*/ val receiver: KSPropertyDeclaration by lazy {
         descriptor.correspondingProperty.toKSPropertyDeclaration()
     }
 
-    override val parent: KSNode? by lazy {
+    open /*override*/ val parent: KSNode? by lazy {
         receiver
     }
 
-    override val location: Location
+    open /*override*/ val location: Location
         get() {
             // if receiver is kotlin source, that means `this` is synthetic hence we want the property's location
             // Otherwise, receiver is also from a .class file where the location will be NoLocation
             return receiver.location
         }
 
-    override val annotations: Sequence<KSAnnotation> by lazy {
-        descriptor.annotations.asSequence().map { KSAnnotationDescriptorImpl.getCached(it, this) }.memoized()
+    open /*override*/ val annotations: Sequence<KSAnnotation> by lazy {
+        descriptor.annotations.asSequence().map { KSAnnotationDescriptorImpl.getCached(it, this as KSPropertyAccessor) }
+            .memoized()
     }
 
-    override val modifiers: Set<Modifier> by lazy {
+    open /*override*/ val modifiers: Set<Modifier> by lazy {
         val modifiers = mutableSetOf<Modifier>()
         modifiers.addAll(descriptor.toKSModifiers())
         modifiers.addAll(descriptor.toFunctionKSModifiers())

compiler-plugin/src/main/kotlin/com/google/devtools/ksp/symbol/impl/java/KSDeclarationJavaImpl.kt

@@ -25,24 +25,24 @@ import com.google.devtools.ksp.symbol.impl.findParentDeclaration
 import com.google.devtools.ksp.symbol.impl.getDocString
 import com.intellij.psi.PsiElement
 
-abstract class KSDeclarationJavaImpl(private val psi: PsiElement) : KSDeclaration {
-    override val packageName: KSName by lazy {
-        this.containingFile!!.packageName
+abstract class KSDeclarationJavaImpl(private val psi: PsiElement) /*: KSDeclaration*/ {
+    open /*override*/ val packageName: KSName by lazy {
+        (this as KSDeclaration).containingFile!!.packageName
     }
 
     override fun toString(): String {
-        return this.simpleName.asString()
+        return (this as KSDeclaration).simpleName.asString()
     }
 
-    override val docString by lazy {
+    open /*override*/ val docString by lazy {
         psi.getDocString()
     }
 
-    override val parentDeclaration: KSDeclaration? by lazy {
+    open /*override*/ val parentDeclaration: KSDeclaration? by lazy {
         psi.findParentDeclaration()
     }
 
-    override val parent: KSNode? by lazy {
+    open /*override*/ val parent: KSNode? by lazy {
         psi.findParentAnnotated()
     }
 }