Serialize error type to proto when generating stubs

compiler/backend/src/org/jetbrains/kotlin/codegen/serialization/JvmSerializerExtension.java

@@ -19,6 +19,7 @@ package org.jetbrains.kotlin.codegen.serialization;
 import com.intellij.openapi.util.Pair;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
+import org.jetbrains.kotlin.codegen.ClassBuilderMode;
 import org.jetbrains.kotlin.codegen.state.GenerationState;
 import org.jetbrains.kotlin.descriptors.*;
 import org.jetbrains.kotlin.descriptors.annotations.AnnotationDescriptor;
@@ -43,6 +44,7 @@ public class JvmSerializerExtension extends SerializerExtension {
     private final AnnotationSerializer annotationSerializer;
     private final boolean useTypeTable;
     private final String moduleName;
+    private final ClassBuilderMode classBuilderMode;
 
     public JvmSerializerExtension(@NotNull JvmSerializationBindings bindings, @NotNull GenerationState state) {
         this.bindings = bindings;
@@ -50,6 +52,7 @@ public class JvmSerializerExtension extends SerializerExtension {
         this.annotationSerializer = new AnnotationSerializer(stringTable);
         this.useTypeTable = state.getUseTypeTableInSerializer();
         this.moduleName = state.getModuleName();
+        this.classBuilderMode = state.getClassBuilderMode();
     }
 
     @NotNull
@@ -144,6 +147,16 @@ public class JvmSerializerExtension extends SerializerExtension {
         proto.setExtension(JvmProtoBuf.propertySignature, signature);
     }
 
+    @Override
+    public void serializeErrorType(@NotNull KotlinType type, @NotNull ProtoBuf.Type.Builder builder) {
+        if (classBuilderMode == ClassBuilderMode.LIGHT_CLASSES_WITH_METADATA) {
+            builder.setClassName(stringTable.getStringIndex("error.NonExistingClass"));
+            return;
+        }
+
+        super.serializeErrorType(type, builder);
+    }
+
     private class SignatureSerializer {
         @Nullable
         public JvmProtoBuf.JvmMethodSignature methodSignature(@Nullable FunctionDescriptor descriptor, @NotNull Method method) {

compiler/serialization/src/org/jetbrains/kotlin/serialization/DescriptorSerializer.java

@@ -459,7 +459,12 @@ public class DescriptorSerializer {
 
     @NotNull
     private ProtoBuf.Type.Builder type(@NotNull KotlinType type) {
-        assert !type.isError() : "Can't serialize error types: " + type; // TODO
+        ProtoBuf.Type.Builder builder = ProtoBuf.Type.newBuilder();
+
+        if (type.isError()) {
+            extension.serializeErrorType(type, builder);
+            return builder;
+        }
 
         if (FlexibleTypesKt.isFlexible(type)) {
             Flexibility flexibility = FlexibleTypesKt.flexibility(type);
@@ -475,8 +480,6 @@ public class DescriptorSerializer {
             return lowerBound;
         }
 
-        ProtoBuf.Type.Builder builder = ProtoBuf.Type.newBuilder();
-
         ClassifierDescriptor descriptor = type.getConstructor().getDeclarationDescriptor();
         if (descriptor instanceof ClassDescriptor) {
             PossiblyInnerType possiblyInnerType = TypeParameterUtilsKt.buildPossiblyInnerType(type);

compiler/serialization/src/org/jetbrains/kotlin/serialization/SerializerExtension.java

@@ -54,4 +54,8 @@ public abstract class SerializerExtension {
 
     public void serializeTypeParameter(@NotNull TypeParameterDescriptor typeParameter, @NotNull ProtoBuf.TypeParameter.Builder proto) {
     }
+
+    public void serializeErrorType(@NotNull KotlinType type, @NotNull ProtoBuf.Type.Builder builder) {
+         throw new IllegalStateException("Cannot serialize error type: " + type);
+    }
 }