[bindings] Don't require trait impl for-structs to have no generics

This (finally) exposes `ChannelManager`/`ChannelMonitor` _write
methods, which were (needlessly) excluded as the structs themselves
have generic parameters. Sadly, we also now need to parse
`(C-not exported)` doc comments on impl blocks as we otherwise try
to expose _write methods for `&Vec<RouteHop>`, which doesn't work
(and isn't particularly interesting for users anyway). We add such
doc comments there.

Author: TheBlueMatt

c-bindings-gen/src/main.rs

@@ -65,7 +65,7 @@ fn maybe_convert_trait_impl<W: std::io::Write>(w: &mut W, trait_path: &syn::Path
 		let full_obj_path;
 		let mut has_inner = false;
 		if let syn::Type::Path(ref p) = for_ty {
-			if let Some(ident) = p.path.get_ident() {
+			if let Some(ident) = single_ident_generic_path_to_ident(&p.path) {
 				for_obj = format!("{}", ident);
 				full_obj_path = for_obj.clone();
 				has_inner = types.c_type_has_inner_from_path(&types.resolve_path(&p.path, Some(generics)));
@@ -706,6 +706,11 @@ fn writeln_struct<'a, 'b, W: std::io::Write>(w: &mut W, s: &'a syn::ItemStruct,
 ///
 /// A few non-crate Traits are hard-coded including Default.
 fn writeln_impl<W: std::io::Write>(w: &mut W, i: &syn::ItemImpl, types: &mut TypeResolver) {
+	match export_status(&i.attrs) {
+		ExportStatus::Export => {},
+		ExportStatus::NoExport|ExportStatus::TestOnly => return,
+	}
+
 	if let syn::Type::Tuple(_) = &*i.self_ty {
 		if types.understood_c_type(&*i.self_ty, None) {
 			let mut gen_types = GenericTypes::new();
@@ -952,10 +957,9 @@ fn writeln_impl<W: std::io::Write>(w: &mut W, i: &syn::ItemImpl, types: &mut Typ
 							},
 							"PartialEq" => {},
 							// If we have no generics, try a manual implementation:
-							_ if p.path.get_ident().is_some() => maybe_convert_trait_impl(w, &trait_path.1, &*i.self_ty, types, &gen_types),
-							_ => {},
+							_ => maybe_convert_trait_impl(w, &trait_path.1, &*i.self_ty, types, &gen_types),
 						}
-					} else if p.path.get_ident().is_some() {
+					} else {
 						// If we have no generics, try a manual implementation:
 						maybe_convert_trait_impl(w, &trait_path.1, &*i.self_ty, types, &gen_types);
 					}

lightning/src/ln/chan_utils.rs

@@ -843,6 +843,7 @@ impl PartialEq for CommitmentTransaction {
 	}
 }
 
+/// (C-not exported) as users never need to call this directly
 impl Writeable for Vec<HTLCOutputInCommitment> {
 	#[inline]
 	fn write<W: Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {
@@ -854,6 +855,7 @@ impl Writeable for Vec<HTLCOutputInCommitment> {
 	}
 }
 
+/// (C-not exported) as users never need to call this directly
 impl Readable for Vec<HTLCOutputInCommitment> {
 	#[inline]
 	fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {

lightning/src/routing/router.rs

@@ -45,6 +45,7 @@ pub struct RouteHop {
 	pub cltv_expiry_delta: u32,
 }
 
+/// (C-not exported)
 impl Writeable for Vec<RouteHop> {
 	fn write<W: ::util::ser::Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 		(self.len() as u8).write(writer)?;
@@ -60,6 +61,7 @@ impl Writeable for Vec<RouteHop> {
 	}
 }
 
+/// (C-not exported)
 impl Readable for Vec<RouteHop> {
 	fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Vec<RouteHop>, DecodeError> {
 		let hops_count: u8 = Readable::read(reader)?;