From: Matt Corallo <git@bluematt.me>
Date: Sun, 8 Oct 2023 05:53:25 +0000 (+0000)
Subject: Update args on supertraits of supertraits when cloning trait impls
X-Git-Tag: v0.0.117.1^2~1
X-Git-Url: http://git.bitcoin.ninja/index.cgi?p=ldk-c-bindings;a=commitdiff_plain;h=6c7a4f5ecc7b225d480d5b5dc021af0a59430ad4

Update args on supertraits of supertraits when cloning trait impls

When cloning implementations of traits from in-crate structs, we
forgot to update the arguments for supertraits of supertraits,
causing methods on that trait to be called against the previous
struct, not the cloned one.

This was ultimately identified downstream in the Java bindings,
fixes https://github.com/lightningdevkit/ldk-garbagecollected/issues/138
---

diff --git a/c-bindings-gen/src/main.rs b/c-bindings-gen/src/main.rs
index c00b32d..22eabf7 100644
--- a/c-bindings-gen/src/main.rs
+++ b/c-bindings-gen/src/main.rs
@@ -1254,15 +1254,22 @@ fn writeln_impl<W: std::io::Write>(w: &mut W, w_uses: &mut HashSet<String, NonRa
 							writeln!(w, "extern \"C\" fn {}_{}_cloned(new_obj: &mut crate::{}) {{", trait_obj.ident, ident, full_trait_path).unwrap();
 							writeln!(w, "\tnew_obj.this_arg = {}_clone_void(new_obj.this_arg);", ident).unwrap();
 							writeln!(w, "\tnew_obj.free = Some({}_free_void);", ident).unwrap();
-							walk_supertraits!(trait_obj, Some(&types), (
-								(s, t, _) => {
-									if types.crate_types.traits.get(s).is_some() {
-										assert!(!types.is_clonable(s)); // We don't currently support cloning with a clonable supertrait
-										writeln!(w, "\tnew_obj.{}.this_arg = new_obj.this_arg;", t).unwrap();
-										writeln!(w, "\tnew_obj.{}.free = None;", t).unwrap();
+
+							fn seek_supertraits<W: std::io::Write>(w: &mut W, pfx: &str, tr: &syn::ItemTrait, types: &TypeResolver) {
+								walk_supertraits!(tr, Some(types), (
+									(s, t, _) => {
+										if types.crate_types.traits.get(s).is_some() {
+											assert!(!types.is_clonable(s)); // We don't currently support cloning with a clonable supertrait
+											writeln!(w, "\tnew_obj.{}{}.this_arg = new_obj.this_arg;", pfx, t).unwrap();
+											writeln!(w, "\tnew_obj.{}{}.free = None;", pfx, t).unwrap();
+											let tr = types.crate_types.traits.get(s).unwrap();
+											let resolver = get_module_type_resolver!(s, types.crate_types);
+											seek_supertraits(w, &format!("{}.", t), tr, &resolver);
+										}
 									}
-								}
-							) );
+								) );
+							}
+							seek_supertraits(w, "", trait_obj, types);
 							writeln!(w, "}}").unwrap();
 						}
 						write!(w, "\n").unwrap();