Handle concrete Deref<Target=X> bounds in generic args

diff --git a/c-bindings-gen/src/types.rs b/c-bindings-gen/src/types.rs
index 26a0885588f4c5e77fc00bc38cf941773c0791f7..bd0c9c5ceecc8cfcb4aaa8ce175cda800d73ddab 100644 (file)
--- a/c-bindings-gen/src/types.rs
+++ b/c-bindings-gen/src/types.rs
@@ -176,7 +176,7 @@ pub struct GenericTypes<'a, 'b> {
        self_ty: Option<(String, &'a syn::Path)>,
        parent: Option<&'b GenericTypes<'b, 'b>>,
        typed_generics: HashMap<&'a syn::Ident, (String, Option<&'a syn::Path>)>,
-       default_generics: HashMap<&'a syn::Ident, (&'a syn::Type, syn::Type)>,
+       default_generics: HashMap<&'a syn::Ident, (syn::Type, syn::Type)>,
 }
 impl<'a, 'p: 'a> GenericTypes<'a, 'p> {
        pub fn new(self_ty: Option<(String, &'a syn::Path)>) -> Self {
@@ -197,7 +197,7 @@ impl<'a, 'p: 'a> GenericTypes<'a, 'p> {
                        match generic {
                                syn::GenericParam::Type(type_param) => {
                                        let mut non_lifetimes_processed = false;
-                                       for bound in type_param.bounds.iter() {
+                                       'bound_loop: for bound in type_param.bounds.iter() {
                                                if let syn::TypeParamBound::Trait(trait_bound) = bound {
                                                        if let Some(ident) = single_ident_generic_path_to_ident(&trait_bound.path) {
                                                                match &format!("{}", ident) as &str { "Send" => continue, "Sync" => continue, _ => {} }
@@ -213,6 +213,26 @@ impl<'a, 'p: 'a> GenericTypes<'a, 'p> {
                                                                let new_ident = if path != "std::ops::Deref" && path != "core::ops::Deref" {
                                                                        path = "crate::".to_string() + &path;
                                                                        Some(&trait_bound.path)
+                                                               } else if trait_bound.path.segments.len() == 1 {
+                                                                       // If we're templated on Deref<Target = ConcreteThing>, store
+                                                                       // the reference type in `default_generics` which handles full
+                                                                       // types and not just paths.
+                                                                       if let syn::PathArguments::AngleBracketed(ref args) =
+                                                                                       trait_bound.path.segments[0].arguments {
+                                                                               for subargument in args.args.iter() {
+                                                                                       match subargument {
+                                                                                               syn::GenericArgument::Lifetime(_) => {},
+                                                                                               syn::GenericArgument::Binding(ref b) => {
+                                                                                                       if &format!("{}", b.ident) != "Target" { return false; }
+                                                                                                       let default = &b.ty;
+                                                                                                       self.default_generics.insert(&type_param.ident, (parse_quote!(&#default), parse_quote!(&#default)));
+                                                                                                       break 'bound_loop;
+                                                                                               },
+                                                                                               _ => unimplemented!(),
+                                                                                       }
+                                                                               }
+                                                                               None
+                                                                       } else { None }
                                                                } else { None };
                                                                self.typed_generics.insert(&type_param.ident, (path, new_ident));
                                                        } else { return false; }
@@ -220,7 +240,7 @@ impl<'a, 'p: 'a> GenericTypes<'a, 'p> {
                                        }
                                        if let Some(default) = type_param.default.as_ref() {
                                                assert!(type_param.bounds.is_empty());
-                                               self.default_generics.insert(&type_param.ident, (default, parse_quote!(&#default)));
+                                               self.default_generics.insert(&type_param.ident, (default.clone(), parse_quote!(&#default)));
                                        }
                                },
                                _ => {},