From 0c8893513730a1b9d2deefad3d0e3af51f197b84 Mon Sep 17 00:00:00 2001
From: Jan Haller <bromeon@gmail.com>
Date: Mon, 17 Jul 2023 20:43:23 +0200
Subject: [PATCH] Make GodotClass an unsafe trait and document usage

---
 godot-codegen/src/class_generator.rs       |  2 +-
 godot-core/src/obj/traits.rs               | 11 ++++++++---
 godot-macros/src/derive_godot_class/mod.rs |  2 +-
 godot-macros/src/lib.rs                    |  4 ++--
 4 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/godot-codegen/src/class_generator.rs b/godot-codegen/src/class_generator.rs
index 2fcd44ca2..60691ece6 100644
--- a/godot-codegen/src/class_generator.rs
+++ b/godot-codegen/src/class_generator.rs
@@ -562,7 +562,7 @@ fn make_class(class: &Class, class_name: &TyName, ctx: &mut Context) -> Generate
                 #methods
                 #constants
             }
-            impl crate::obj::GodotClass for #class_name {
+            unsafe impl crate::obj::GodotClass for #class_name {
                 type Base = #base_ty;
                 type Declarer = crate::obj::dom::EngineDomain;
                 type Mem = crate::obj::mem::#memory;
diff --git a/godot-core/src/obj/traits.rs b/godot-core/src/obj/traits.rs
index 01e9b1b2b..351774226 100644
--- a/godot-core/src/obj/traits.rs
+++ b/godot-core/src/obj/traits.rs
@@ -14,8 +14,11 @@ use godot_ffi as sys;
 ///
 /// The behavior of types implementing this trait is influenced by the associated types; check their documentation for information.
 ///
-/// You wouldn't usually implement this trait yourself; use the [`GodotClass`](godot_macros::GodotClass) derive macro instead.
-pub trait GodotClass: 'static
+/// # Safety
+///
+/// Internal.
+/// **You must not implement this trait yourself; use the [`GodotClass`](crate::bind::GodotClass) derive macro instead.**
+pub unsafe trait GodotClass: 'static
 where
     Self: Sized,
 {
@@ -51,7 +54,7 @@ where
 }
 
 /// Unit impl only exists to represent "no base", and is used for exactly one class: `Object`.
-impl GodotClass for () {
+unsafe impl GodotClass for () {
     type Base = ();
     type Declarer = dom::EngineDomain;
     type Mem = mem::ManualMemory;
@@ -286,6 +289,8 @@ pub mod mem {
             false
         }
     }
+
+    #[doc(hidden)]
     pub trait PossiblyManual {}
 
     /// Memory managed through Godot reference counter (always present).
diff --git a/godot-macros/src/derive_godot_class/mod.rs b/godot-macros/src/derive_godot_class/mod.rs
index 0e2b439c2..44f33ec58 100644
--- a/godot-macros/src/derive_godot_class/mod.rs
+++ b/godot-macros/src/derive_godot_class/mod.rs
@@ -44,7 +44,7 @@ pub fn transform(decl: Declaration) -> ParseResult<TokenStream> {
     };
 
     Ok(quote! {
-        impl ::godot::obj::GodotClass for #class_name {
+        unsafe impl ::godot::obj::GodotClass for #class_name {
             type Base = ::godot::engine::#base_ty;
             type Declarer = ::godot::obj::dom::UserDomain;
             type Mem = <Self::Base as ::godot::obj::GodotClass>::Mem;
diff --git a/godot-macros/src/lib.rs b/godot-macros/src/lib.rs
index 41627a8e1..2cad132f3 100644
--- a/godot-macros/src/lib.rs
+++ b/godot-macros/src/lib.rs
@@ -96,8 +96,8 @@ mod itest;
 mod method_registration;
 mod util;
 
-/// Derive macro for [`GodotClass`](godot_core::obj::GodotClass) on structs. You should normally use
-/// this macro, rather than implement `GodotClass` manually for your type.
+/// Derive macro for [`GodotClass`](godot_core::obj::GodotClass) on structs. You must use this
+/// macro; manual implementations of the `GodotClass` traits are not supported.
 ///
 /// # Construction
 ///