X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=c-bindings-gen%2Fsrc%2Fmain.rs;h=b04d6b007828f9adc40eef56dae5bca551cc65b9;hb=c3d52f5f16d850662ab046a8eaf6cda9a3e40a72;hp=4193f6d36206c14bc47c3aa733b23b355f5e529e;hpb=52673d480e615b8b5113435e588da24267316c2e;p=rust-lightning diff --git a/c-bindings-gen/src/main.rs b/c-bindings-gen/src/main.rs index 4193f6d36..b04d6b007 100644 --- a/c-bindings-gen/src/main.rs +++ b/c-bindings-gen/src/main.rs @@ -80,6 +80,19 @@ fn maybe_convert_trait_impl(w: &mut W, trait_path: &syn::Path } } +/// 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 { + "util::events::MessageSendEventsProvider" => { + writeln!(w, "impl lightning::{} for {} {{", trait_path, for_obj).unwrap(); + writeln!(w, "\tfn get_and_clear_pending_msg_events(&self) -> Vec {{").unwrap(); + writeln!(w, "\t\t::get_and_clear_pending_msg_events(&self.{})", trait_path, trait_path, trait_name).unwrap(); + writeln!(w, "\t}}\n}}").unwrap(); + }, + _ => panic!(), + } +} + // ******************************* // *** Per-Type Printing Logic *** // ******************************* @@ -92,15 +105,18 @@ macro_rules! walk_supertraits { ($t: expr, $types: expr, ($( $pat: pat => $e: ex if supertrait.paren_token.is_some() || supertrait.lifetimes.is_some() { unimplemented!(); } - if let Some(ident) = supertrait.path.get_ident() { - match (&format!("{}", ident) as &str, &ident) { + // First try to resolve path to find in-crate traits, but if that doesn't work + // assume its a prelude trait (eg Clone, etc) and just use the single ident. + if let Some(path) = $types.maybe_resolve_path(&supertrait.path, None) { + match (&path as &str, &supertrait.path.segments.iter().last().unwrap().ident) { $( $pat => $e, )* } - } else { - let path = $types.resolve_path(&supertrait.path, None); - match (&path as &str, &supertrait.path.segments.iter().last().unwrap().ident) { + } else if let Some(ident) = supertrait.path.get_ident() { + match (&format!("{}", ident) as &str, &ident) { $( $pat => $e, )* } + } else { + panic!("Supertrait unresolvable and not single-ident"); } }, syn::TypeParamBound::Lifetime(_) => unimplemented!(), @@ -109,31 +125,6 @@ macro_rules! walk_supertraits { ($t: expr, $types: expr, ($( $pat: pat => $e: ex } } } } -/// Gets a HashMap from name idents to the bounding trait for associated types. -/// eg if a native trait has a "type T = TraitA", this will return a HashMap containing a mapping -/// from "T" to "TraitA". -fn learn_associated_types<'a>(t: &'a syn::ItemTrait) -> HashMap<&'a syn::Ident, &'a syn::Ident> { - let mut associated_types = HashMap::new(); - for item in t.items.iter() { - match item { - &syn::TraitItem::Type(ref t) => { - if t.default.is_some() || t.generics.lt_token.is_some() { unimplemented!(); } - let mut bounds_iter = t.bounds.iter(); - match bounds_iter.next().unwrap() { - syn::TypeParamBound::Trait(tr) => { - assert_simple_bound(&tr); - associated_types.insert(&t.ident, assert_single_path_seg(&tr.path)); - }, - _ => unimplemented!(), - } - if bounds_iter.next().is_some() { unimplemented!(); } - }, - _ => {}, - } - } - associated_types -} - /// Prints a C-mapped trait object containing a void pointer and a jump table for each function in /// the original trait. /// Implements the native Rust trait and relevant parent traits for the new C-mapped trait. @@ -150,10 +141,10 @@ fn writeln_trait<'a, 'b, W: std::io::Write>(w: &mut W, t: &'a syn::ItemTrait, ty let mut gen_types = GenericTypes::new(); assert!(gen_types.learn_generics(&t.generics, types)); + gen_types.learn_associated_types(&t, types); writeln!(w, "#[repr(C)]\npub struct {} {{", trait_name).unwrap(); writeln!(w, "\tpub this_arg: *mut c_void,").unwrap(); - let associated_types = learn_associated_types(t); let mut generated_fields = Vec::new(); // Every field's name except this_arg, used in Clone generation for item in t.items.iter() { match item { @@ -210,7 +201,7 @@ fn writeln_trait<'a, 'b, W: std::io::Write>(w: &mut W, t: &'a syn::ItemTrait, ty write!(w, "\tpub {}: extern \"C\" fn (", m.sig.ident).unwrap(); generated_fields.push(format!("{}", m.sig.ident)); - write_method_params(w, &m.sig, &associated_types, "c_void", types, Some(&gen_types), true, false); + write_method_params(w, &m.sig, "c_void", types, Some(&gen_types), true, false); writeln!(w, ",").unwrap(); gen_types.pop_ctx(); @@ -273,13 +264,7 @@ fn writeln_trait<'a, 'b, W: std::io::Write>(w: &mut W, t: &'a syn::ItemTrait, ty writeln!(w, "\t}}\n}}").unwrap(); }, (s, i) => { - if s != "util::events::MessageSendEventsProvider" { unimplemented!(); } - // XXX: We straight-up cheat here - instead of bothering to get the trait object we - // just print what we need since this is only used in one place. - writeln!(w, "impl lightning::{} for {} {{", s, trait_name).unwrap(); - writeln!(w, "\tfn get_and_clear_pending_msg_events(&self) -> Vec {{").unwrap(); - writeln!(w, "\t\t::get_and_clear_pending_msg_events(&self.{})", s, s, i).unwrap(); - writeln!(w, "\t}}\n}}").unwrap(); + do_write_impl_trait(w, s, i, &trait_name); } ) ); @@ -363,7 +348,7 @@ fn writeln_trait<'a, 'b, W: std::io::Write>(w: &mut W, t: &'a syn::ItemTrait, ty } write_method_var_decl_body(w, &m.sig, "\t", types, Some(&gen_types), true); write!(w, "(self.{})(", m.sig.ident).unwrap(); - write_method_call_params(w, &m.sig, &associated_types, "\t", types, Some(&gen_types), "", true); + write_method_call_params(w, &m.sig, "\t", types, Some(&gen_types), "", true); writeln!(w, "\n\t}}").unwrap(); gen_types.pop_ctx(); @@ -605,7 +590,7 @@ fn writeln_impl(w: &mut W, i: &syn::ItemImpl, types: &mut Typ // That's great, except that they are unresolved idents, so if we learn // mappings from a trai defined in a different file, we may mis-resolve or // fail to resolve the mapped types. - let trait_associated_types = learn_associated_types(trait_obj); + gen_types.learn_associated_types(trait_obj, types); let mut impl_associated_types = HashMap::new(); for item in i.items.iter() { match item { @@ -625,6 +610,21 @@ fn writeln_impl(w: &mut W, i: &syn::ItemImpl, types: &mut Typ ExportStatus::Export => {}, ExportStatus::NoExport|ExportStatus::TestOnly => return, } + + // For cases where we have a concrete native object which implements a + // trait and need to return the C-mapped version of the trait, provide a + // From<> implementation which does all the work to ensure free is handled + // properly. This way we can call this method from deep in the + // type-conversion logic without actually knowing the concrete native type. + writeln!(w, "impl From for crate::{} {{", ident, full_trait_path).unwrap(); + writeln!(w, "\tfn from(obj: native{}) -> Self {{", ident).unwrap(); + writeln!(w, "\t\tlet mut rust_obj = {} {{ inner: Box::into_raw(Box::new(obj)), is_owned: true }};", ident).unwrap(); + writeln!(w, "\t\tlet mut ret = {}_as_{}(&rust_obj);", ident, trait_obj.ident).unwrap(); + writeln!(w, "\t\t// We want to free rust_obj when ret gets drop()'d, not rust_obj, so wipe rust_obj's pointer and set ret's free() fn").unwrap(); + writeln!(w, "\t\trust_obj.inner = std::ptr::null_mut();").unwrap(); + writeln!(w, "\t\tret.free = Some({}_free_void);", ident).unwrap(); + writeln!(w, "\t\tret\n\t}}\n}}").unwrap(); + write!(w, "#[no_mangle]\npub extern \"C\" fn {}_as_{}(this_arg: *const {}) -> crate::{} {{\n", ident, trait_obj.ident, ident, full_trait_path).unwrap(); writeln!(w, "\tcrate::{} {{", full_trait_path).unwrap(); writeln!(w, "\t\tthis_arg: unsafe {{ (*this_arg).inner as *mut c_void }},").unwrap(); @@ -671,8 +671,7 @@ fn writeln_impl(w: &mut W, i: &syn::ItemImpl, types: &mut Typ writeln!(w, "\t\tclone: Some({}_clone_void),", ident).unwrap(); }, (s, t) => { - if s.starts_with("util::") { - let supertrait_obj = types.crate_types.traits.get(s).unwrap(); + if let Some(supertrait_obj) = types.crate_types.traits.get(s) { writeln!(w, "\t\t{}: crate::{} {{", t, s).unwrap(); writeln!(w, "\t\t\tthis_arg: unsafe {{ (*this_arg).inner as *mut c_void }},").unwrap(); writeln!(w, "\t\t\tfree: None,").unwrap(); @@ -706,7 +705,7 @@ fn writeln_impl(w: &mut W, i: &syn::ItemImpl, types: &mut Typ write!(w, "extern \"C\" fn {}_{}_{}(", ident, trait_obj.ident, $m.sig.ident).unwrap(); gen_types.push_ctx(); assert!(gen_types.learn_generics(&$m.sig.generics, types)); - write_method_params(w, &$m.sig, &trait_associated_types, "c_void", types, Some(&gen_types), true, true); + write_method_params(w, &$m.sig, "c_void", types, Some(&gen_types), true, true); write!(w, " {{\n\t").unwrap(); write_method_var_decl_body(w, &$m.sig, "", types, Some(&gen_types), false); let mut takes_self = false; @@ -732,7 +731,7 @@ fn writeln_impl(w: &mut W, i: &syn::ItemImpl, types: &mut Typ }, _ => {}, } - write_method_call_params(w, &$m.sig, &trait_associated_types, "", types, Some(&gen_types), &real_type, false); + write_method_call_params(w, &$m.sig, "", types, Some(&gen_types), &real_type, false); gen_types.pop_ctx(); write!(w, "\n}}\n").unwrap(); if let syn::ReturnType::Type(_, rtype) = &$m.sig.output { @@ -763,9 +762,8 @@ fn writeln_impl(w: &mut W, i: &syn::ItemImpl, types: &mut Typ } walk_supertraits!(trait_obj, types, ( (s, t) => { - if s.starts_with("util::") { + if let Some(supertrait_obj) = types.crate_types.traits.get(s).cloned() { writeln!(w, "use {}::{} as native{}Trait;", types.orig_crate, s, t).unwrap(); - let supertrait_obj = *types.crate_types.traits.get(s).unwrap(); for item in supertrait_obj.items.iter() { match item { syn::TraitItem::Method(m) => { @@ -819,7 +817,7 @@ fn writeln_impl(w: &mut W, i: &syn::ItemImpl, types: &mut Typ }; gen_types.push_ctx(); assert!(gen_types.learn_generics(&m.sig.generics, types)); - write_method_params(w, &m.sig, &HashMap::new(), &ret_type, types, Some(&gen_types), false, true); + write_method_params(w, &m.sig, &ret_type, types, Some(&gen_types), false, true); write!(w, " {{\n\t").unwrap(); write_method_var_decl_body(w, &m.sig, "", types, Some(&gen_types), false); let mut takes_self = false; @@ -837,7 +835,7 @@ fn writeln_impl(w: &mut W, i: &syn::ItemImpl, types: &mut Typ } else { write!(w, "{}::{}::{}(", types.orig_crate, resolved_path, m.sig.ident).unwrap(); } - write_method_call_params(w, &m.sig, &HashMap::new(), "", types, Some(&gen_types), &ret_type, false); + write_method_call_params(w, &m.sig, "", types, Some(&gen_types), &ret_type, false); gen_types.pop_ctx(); writeln!(w, "\n}}\n").unwrap(); } @@ -1018,11 +1016,11 @@ fn writeln_fn<'a, 'b, W: std::io::Write>(w: &mut W, f: &'a syn::ItemFn, types: & if !gen_types.learn_generics(&f.sig.generics, types) { return; } write!(w, "#[no_mangle]\npub extern \"C\" fn {}(", f.sig.ident).unwrap(); - write_method_params(w, &f.sig, &HashMap::new(), "", types, Some(&gen_types), false, true); + write_method_params(w, &f.sig, "", types, Some(&gen_types), false, true); write!(w, " {{\n\t").unwrap(); write_method_var_decl_body(w, &f.sig, "", types, Some(&gen_types), false); write!(w, "{}::{}::{}(", types.orig_crate, types.module_path, f.sig.ident).unwrap(); - write_method_call_params(w, &f.sig, &HashMap::new(), "", types, Some(&gen_types), "", false); + write_method_call_params(w, &f.sig, "", types, Some(&gen_types), "", false); writeln!(w, "\n}}\n").unwrap(); }