From 52e55d4570e58b96d142a77f26efa81347d11ba1 Mon Sep 17 00:00:00 2001 From: Matt Corallo Date: Wed, 25 Nov 2020 12:22:31 -0500 Subject: [PATCH] [bindings] Add support for mapping Write as a supertrait --- c-bindings-gen/src/main.rs | 54 +++++++++++++++++++++++++++++++++++--- 1 file changed, 50 insertions(+), 4 deletions(-) diff --git a/c-bindings-gen/src/main.rs b/c-bindings-gen/src/main.rs index b04d6b007..6d6296c8f 100644 --- a/c-bindings-gen/src/main.rs +++ b/c-bindings-gen/src/main.rs @@ -42,6 +42,10 @@ fn convert_macro(w: &mut W, macro_path: &syn::Path, stream: & writeln!(w, "\tcrate::c_types::serialize_obj(unsafe {{ &(*(*obj).inner) }})").unwrap(); writeln!(w, "}}").unwrap(); writeln!(w, "#[no_mangle]").unwrap(); + writeln!(w, "pub(crate) extern \"C\" fn {}_write_void(obj: *const c_void) -> crate::c_types::derived::CVec_u8Z {{", struct_for).unwrap(); + writeln!(w, "\tcrate::c_types::serialize_obj(unsafe {{ &*(obj as *const native{}) }})", struct_for).unwrap(); + writeln!(w, "}}").unwrap(); + writeln!(w, "#[no_mangle]").unwrap(); writeln!(w, "pub extern \"C\" fn {}_read(ser: crate::c_types::u8slice) -> {} {{", struct_for, struct_for).unwrap(); writeln!(w, "\tif let Ok(res) = crate::c_types::deserialize_obj(ser) {{").unwrap(); writeln!(w, "\t\t{} {{ inner: Box::into_raw(Box::new(res)), is_owned: true }}", struct_for).unwrap(); @@ -65,6 +69,10 @@ fn maybe_convert_trait_impl(w: &mut W, trait_path: &syn::Path writeln!(w, "pub extern \"C\" fn {}_write(obj: *const {}) -> crate::c_types::derived::CVec_u8Z {{", for_obj, for_obj).unwrap(); writeln!(w, "\tcrate::c_types::serialize_obj(unsafe {{ &(*(*obj).inner) }})").unwrap(); writeln!(w, "}}").unwrap(); + writeln!(w, "#[no_mangle]").unwrap(); + writeln!(w, "pub(crate) extern \"C\" fn {}_write_void(obj: *const c_void) -> crate::c_types::derived::CVec_u8Z {{", for_obj).unwrap(); + writeln!(w, "\tcrate::c_types::serialize_obj(unsafe {{ &*(obj as *const native{}) }})", for_obj).unwrap(); + writeln!(w, "}}").unwrap(); }, "util::ser::Readable" => { writeln!(w, "#[no_mangle]").unwrap(); @@ -80,6 +88,28 @@ fn maybe_convert_trait_impl(w: &mut W, trait_path: &syn::Path } } +/// Convert "TraitA : TraitB" to a single function name and return type. +/// +/// This is (obviously) somewhat over-specialized and only useful for TraitB's that only require a +/// single function (eg for serialization). +fn convert_trait_impl_field(trait_path: &str) -> (String, &'static str) { + match trait_path { + "util::ser::Writeable" => ("write".to_owned(), "crate::c_types::derived::CVec_u8Z"), + _ => unimplemented!(), + } +} + +/// Companion to convert_trait_impl_field, write an assignment for the function defined by it for +/// `for_obj` which implements the the trait at `trait_path`. +fn write_trait_impl_field_assign(w: &mut W, trait_path: &str, for_obj: &syn::Ident) { + match trait_path { + "util::ser::Writeable" => { + writeln!(w, "\t\twrite: {}_write_void,", for_obj).unwrap(); + }, + _ => unimplemented!(), + } +} + /// Write out the impl block for a defined trait struct which has a supertrait fn do_write_impl_trait(w: &mut W, trait_path: &str, trait_name: &syn::Ident, for_obj: &str) { match trait_path { @@ -89,6 +119,13 @@ fn do_write_impl_trait(w: &mut W, trait_path: &str, trait_nam writeln!(w, "\t\t::get_and_clear_pending_msg_events(&self.{})", trait_path, trait_path, trait_name).unwrap(); writeln!(w, "\t}}\n}}").unwrap(); }, + "util::ser::Writeable" => { + writeln!(w, "impl lightning::{} for {} {{", trait_path, for_obj).unwrap(); + writeln!(w, "\tfn write(&self, w: &mut W) -> Result<(), ::std::io::Error> {{").unwrap(); + writeln!(w, "\t\tlet vec = (self.write)(self.this_arg);").unwrap(); + writeln!(w, "\t\tw.write_all(vec.as_slice())").unwrap(); + writeln!(w, "\t}}\n}}").unwrap(); + }, _ => panic!(), } } @@ -227,10 +264,15 @@ fn writeln_trait<'a, 'b, W: std::io::Write>(w: &mut W, t: &'a syn::ItemTrait, ty }, ("Send", _) => {}, ("Sync", _) => {}, (s, i) => { - // For in-crate supertraits, just store a C-mapped copy of the supertrait as a member. - if types.crate_types.traits.get(s).is_none() { unimplemented!(); } - writeln!(w, "\tpub {}: crate::{},", i, s).unwrap(); - generated_fields.push(format!("{}", i)); + generated_fields.push(if types.crate_types.traits.get(s).is_none() { + let (name, ret) = convert_trait_impl_field(s); + writeln!(w, "\tpub {}: extern \"C\" fn (this_arg: *const c_void) -> {},", name, ret).unwrap(); + name + } else { + // For in-crate supertraits, just store a C-mapped copy of the supertrait as a member. + writeln!(w, "\tpub {}: crate::{},", i, s).unwrap(); + format!("{}", i) + }); } ) ); writeln!(w, "\tpub free: Option,").unwrap(); @@ -670,6 +712,8 @@ fn writeln_impl(w: &mut W, i: &syn::ItemImpl, types: &mut Typ ("Clone", _) => { writeln!(w, "\t\tclone: Some({}_clone_void),", ident).unwrap(); }, + ("Sync", _) => {}, ("Send", _) => {}, + ("std::marker::Sync", _) => {}, ("std::marker::Send", _) => {}, (s, t) => { if let Some(supertrait_obj) = types.crate_types.traits.get(s) { writeln!(w, "\t\t{}: crate::{} {{", t, s).unwrap(); @@ -684,6 +728,8 @@ fn writeln_impl(w: &mut W, i: &syn::ItemImpl, types: &mut Typ } } write!(w, "\t\t}},\n").unwrap(); + } else { + write_trait_impl_field_assign(w, s, ident); } } ) ); -- 2.39.5