From ef521e155d142222012acc4b33a41e13c0bda6ee Mon Sep 17 00:00:00 2001 From: Matt Corallo Date: Tue, 28 Jun 2022 02:14:20 +0000 Subject: [PATCH] Add a note in output documentation for fields with refs to opaques Because we (probably shouldn't, but do) map "opaque" structs with an `is_owned` field instead of having a dedicated reference type, fields which are a `Deref` are simply mapped as `OpaqueMappedStruct`. This is confusing for downstream `lightning.h` consumers as they cannot differentiate between a field that expects to own a `Struct` and one which expects to own a reference to it. This is worked around here by adding documentation which can be matched on, though ultimately structs should move towards full ownership. --- c-bindings-gen/src/blocks.rs | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/c-bindings-gen/src/blocks.rs b/c-bindings-gen/src/blocks.rs index 15b3bab..84a971b 100644 --- a/c-bindings-gen/src/blocks.rs +++ b/c-bindings-gen/src/blocks.rs @@ -460,7 +460,7 @@ fn writeln_docs_impl<'a, W: std::io::Write, I>(w: &mut W, attrs: &[syn::Attribut }, } } - if let Some((types, generics, inp, outp, field)) = method_args_ret { + if let Some((types, generics, inp, outp, field_ty)) = method_args_ret { let mut nullable_found = false; for (name, inp) in inp { if types.skip_arg(inp, generics) { continue; } @@ -491,8 +491,13 @@ fn writeln_docs_impl<'a, W: std::io::Write, I>(w: &mut W, attrs: &[syn::Attribut nullable_found = true; writeln!(w, "{}/// Note that the return value (or a relevant inner pointer) may be NULL or all-0s to represent None", prefix).unwrap(); } + let field = field_ty.map(|ty| generics.resolve_type(ty)); if if let Some(syn::Type::Reference(syn::TypeReference { elem, .. })) = field { if let syn::Type::Path(syn::TypePath { ref path, .. }) = &**elem { + let resolved_path = types.resolve_path(path, generics); + if types.crate_types.opaques.get(&resolved_path).is_some() { + writeln!(w, "{}/// Note that this field is expected to be a reference.", prefix).unwrap(); + } types.is_path_transparent_container(path, generics, true) } else { false } } else if let Some(syn::Type::Path(syn::TypePath { ref path, .. })) = field { -- 2.30.2