Add SerializeField private field support

engine/src/Scripting/Mono/MonoScriptRuntime.cpp

@@ -1665,6 +1665,7 @@ void MonoScriptRuntime::Shutdown() {
     m_behaviourClass = nullptr;
     m_gameObjectClass = nullptr;
     m_monoBehaviourClass = nullptr;
+    m_serializeFieldAttributeClass = nullptr;
     m_gameObjectConstructor = nullptr;
     m_managedGameObjectUUIDField = nullptr;
     m_gameObjectUUIDField = nullptr;
@@ -2219,6 +2220,15 @@ bool MonoScriptRuntime::DiscoverScriptClasses() {
         return false;
     }
 
+    m_serializeFieldAttributeClass = mono_class_from_name(
+        m_coreImage,
+        m_settings.baseNamespace.c_str(),
+        "SerializeField");
+    if (!m_serializeFieldAttributeClass) {
+        SetError("Failed to locate the managed SerializeField attribute type.");
+        return false;
+    }
+
     m_gameObjectUUIDField = mono_class_get_field_from_name(m_componentClass, "m_gameObjectUUID");
     m_scriptComponentUUIDField = mono_class_get_field_from_name(m_behaviourClass, "m_scriptComponentUUID");
     if (!m_gameObjectUUIDField || !m_scriptComponentUUIDField) {
@@ -2264,7 +2274,14 @@ void MonoScriptRuntime::DiscoverScriptClassesInImage(const std::string& assembly
         void* fieldIterator = nullptr;
         while (MonoClassField* field = mono_class_get_fields(monoClass, &fieldIterator)) {
             const uint32_t fieldFlags = mono_field_get_flags(field);
-            if ((fieldFlags & MONO_FIELD_ATTR_PUBLIC) == 0 || (fieldFlags & MONO_FIELD_ATTR_STATIC) != 0) {
+            if ((fieldFlags & MONO_FIELD_ATTR_STATIC) != 0
+                || (fieldFlags & MONO_FIELD_ATTR_LITERAL) != 0
+                || (fieldFlags & MONO_FIELD_ATTR_INIT_ONLY) != 0) {
+                continue;
+            }
+
+            const bool isPublicField = (fieldFlags & MONO_FIELD_ATTR_PUBLIC) != 0;
+            if (!isPublicField && !HasSerializeFieldAttribute(field)) {
                 continue;
             }
 
@@ -2299,6 +2316,26 @@ bool MonoScriptRuntime::IsMonoBehaviourSubclass(MonoClass* monoClass) const {
     return false;
 }
 
+bool MonoScriptRuntime::HasSerializeFieldAttribute(MonoClassField* field) const {
+    if (!field || !m_serializeFieldAttributeClass) {
+        return false;
+    }
+
+    MonoClass* ownerClass = mono_field_get_parent(field);
+    if (!ownerClass) {
+        return false;
+    }
+
+    MonoCustomAttrInfo* attributes = mono_custom_attrs_from_field(ownerClass, field);
+    if (!attributes) {
+        return false;
+    }
+
+    const mono_bool hasAttribute = mono_custom_attrs_has_attr(attributes, m_serializeFieldAttributeClass);
+    mono_custom_attrs_free(attributes);
+    return hasAttribute != 0;
+}
+
 MonoScriptRuntime::FieldMetadata MonoScriptRuntime::BuildFieldMetadata(MonoClassField* field) const {
     FieldMetadata metadata;
     metadata.field = field;