[bindings] Support traits with generic arguments (to support #681)

[rust-lightning] / c-bindings-gen / src / types.rs

diff --git a/c-bindings-gen/src/types.rs b/c-bindings-gen/src/types.rs
index 3fc35e8b2558f8de6f7da2d4d017664a8b3390d1..483c1d9b9d12821b427cf8e0e143a56abb9a2400 100644 (file)
--- a/c-bindings-gen/src/types.rs
+++ b/c-bindings-gen/src/types.rs
@@ -932,19 +932,34 @@ impl<'a, 'c: 'a> TypeResolver<'a, 'c> {
        // *** Original Rust Type Printing ***
        // ***********************************
 
-       fn write_rust_path<W: std::io::Write>(&self, w: &mut W, path: &syn::Path) {
-               if let Some(resolved) = self.maybe_resolve_path(&path, None) {
+       fn in_rust_prelude(resolved_path: &str) -> bool {
+               match resolved_path {
+                       "Vec" => true,
+                       "Result" => true,
+                       "Option" => true,
+                       _ => false,
+               }
+       }
+
+       fn write_rust_path<W: std::io::Write>(&self, w: &mut W, generics_resolver: Option<&GenericTypes>, path: &syn::Path) {
+               if let Some(resolved) = self.maybe_resolve_path(&path, generics_resolver) {
                        if self.is_primitive(&resolved) {
                                write!(w, "{}", path.get_ident().unwrap()).unwrap();
                        } else {
-                               if resolved.starts_with("ln::") || resolved.starts_with("chain::") || resolved.starts_with("util::") {
-                                       write!(w, "lightning::{}", resolved).unwrap();
+                               // TODO: We should have a generic "is from a dependency" check here instead of
+                               // checking for "bitcoin" explicitly.
+                               if resolved.starts_with("bitcoin::") || Self::in_rust_prelude(&resolved) {
+                                       write!(w, "{}", resolved).unwrap();
+                               // If we're printing a generic argument, it needs to reference the crate, otherwise
+                               // the original crate:
+                               } else if self.maybe_resolve_path(&path, None).as_ref() == Some(&resolved) {
+                                       write!(w, "{}::{}", self.orig_crate, resolved).unwrap();
                                } else {
-                                       write!(w, "{}", resolved).unwrap(); // XXX: Probably doens't work, get_ident().unwrap()
+                                       write!(w, "crate::{}", resolved).unwrap();
                                }
                        }
                        if let syn::PathArguments::AngleBracketed(args) = &path.segments.iter().last().unwrap().arguments {
-                               self.write_rust_generic_arg(w, args.args.iter());
+                               self.write_rust_generic_arg(w, generics_resolver, args.args.iter());
                        }
                } else {
                        if path.leading_colon.is_some() {
@@ -954,12 +969,12 @@ impl<'a, 'c: 'a> TypeResolver<'a, 'c> {
                                if idx != 0 { write!(w, "::").unwrap(); }
                                write!(w, "{}", seg.ident).unwrap();
                                if let syn::PathArguments::AngleBracketed(args) = &seg.arguments {
-                                       self.write_rust_generic_arg(w, args.args.iter());
+                                       self.write_rust_generic_arg(w, generics_resolver, args.args.iter());
                                }
                        }
                }
        }
-       pub fn write_rust_generic_param<'b, W: std::io::Write>(&self, w: &mut W, generics: impl Iterator<Item=&'b syn::GenericParam>) {
+       pub fn write_rust_generic_param<'b, W: std::io::Write>(&self, w: &mut W, generics_resolver: Option<&GenericTypes>, generics: impl Iterator<Item=&'b syn::GenericParam>) {
                let mut had_params = false;
                for (idx, arg) in generics.enumerate() {
                        if idx != 0 { write!(w, ", ").unwrap(); } else { write!(w, "<").unwrap(); }
@@ -974,7 +989,7 @@ impl<'a, 'c: 'a> TypeResolver<'a, 'c> {
                                                match bound {
                                                        syn::TypeParamBound::Trait(tb) => {
                                                                if tb.paren_token.is_some() || tb.lifetimes.is_some() { unimplemented!(); }
-                                                               self.write_rust_path(w, &tb.path);
+                                                               self.write_rust_path(w, generics_resolver, &tb.path);
                                                        },
                                                        _ => unimplemented!(),
                                                }
@@ -987,24 +1002,24 @@ impl<'a, 'c: 'a> TypeResolver<'a, 'c> {
                if had_params { write!(w, ">").unwrap(); }
        }
 
-       pub fn write_rust_generic_arg<'b, W: std::io::Write>(&self, w: &mut W, generics: impl Iterator<Item=&'b syn::GenericArgument>) {
+       pub fn write_rust_generic_arg<'b, W: std::io::Write>(&self, w: &mut W, generics_resolver: Option<&GenericTypes>, generics: impl Iterator<Item=&'b syn::GenericArgument>) {
                write!(w, "<").unwrap();
                for (idx, arg) in generics.enumerate() {
                        if idx != 0 { write!(w, ", ").unwrap(); }
                        match arg {
-                               syn::GenericArgument::Type(t) => self.write_rust_type(w, t),
+                               syn::GenericArgument::Type(t) => self.write_rust_type(w, generics_resolver, t),
                                _ => unimplemented!(),
                        }
                }
                write!(w, ">").unwrap();
        }
-       pub fn write_rust_type<W: std::io::Write>(&self, w: &mut W, t: &syn::Type) {
+       pub fn write_rust_type<W: std::io::Write>(&self, w: &mut W, generics: Option<&GenericTypes>, t: &syn::Type) {
                match t {
                        syn::Type::Path(p) => {
                                if p.qself.is_some() || p.path.leading_colon.is_some() {
                                        unimplemented!();
                                }
-                               self.write_rust_path(w, &p.path);
+                               self.write_rust_path(w, generics, &p.path);
                        },
                        syn::Type::Reference(r) => {
                                write!(w, "&").unwrap();
@@ -1014,11 +1029,11 @@ impl<'a, 'c: 'a> TypeResolver<'a, 'c> {
                                if r.mutability.is_some() {
                                        write!(w, "mut ").unwrap();
                                }
-                               self.write_rust_type(w, &*r.elem);
+                               self.write_rust_type(w, generics, &*r.elem);
                        },
                        syn::Type::Array(a) => {
                                write!(w, "[").unwrap();
-                               self.write_rust_type(w, &a.elem);
+                               self.write_rust_type(w, generics, &a.elem);
                                if let syn::Expr::Lit(l) = &a.len {
                                        if let syn::Lit::Int(i) = &l.lit {
                                                write!(w, "; {}]", i).unwrap();
@@ -1027,14 +1042,14 @@ impl<'a, 'c: 'a> TypeResolver<'a, 'c> {
                        }
                        syn::Type::Slice(s) => {
                                write!(w, "[").unwrap();
-                               self.write_rust_type(w, &s.elem);
+                               self.write_rust_type(w, generics, &s.elem);
                                write!(w, "]").unwrap();
                        },
                        syn::Type::Tuple(s) => {
                                write!(w, "(").unwrap();
                                for (idx, t) in s.elems.iter().enumerate() {
                                        if idx != 0 { write!(w, ", ").unwrap(); }
-                                       self.write_rust_type(w, &t);
+                                       self.write_rust_type(w, generics, &t);
                                }
                                write!(w, ")").unwrap();
                        },
@@ -1743,7 +1758,7 @@ impl<'a, 'c: 'a> TypeResolver<'a, 'c> {
                                        } else if in_crate {
                                                write!(w, "{}", c_type).unwrap();
                                        } else {
-                                               self.write_rust_type(w, &t);
+                                               self.write_rust_type(w, None, &t);
                                        }
                                } else {
                                        // If we just write out resolved_generic, it may mostly work, however for