[C++ bindings] Add move-assign operator, require rvalue for move
[rust-lightning] / c-bindings-gen / src / main.rs
index c197839c9249a3443396ff90159280f4c5a4857f..8d158e2f4816ae2997ad4aa6be404d45ef7f76c2 100644 (file)
@@ -38,7 +38,7 @@ fn convert_macro<W: std::io::Write>(w: &mut W, macro_path: &syn::Path, stream: &
                        if let Some(s) = types.maybe_resolve_ident(&struct_for) {
                                if !types.crate_types.opaques.get(&s).is_some() { return; }
                                writeln!(w, "#[no_mangle]").unwrap();
-                               writeln!(w, "pub extern \"C\" fn {}_write(obj: *const {}) -> crate::c_types::derived::CVec_u8Z {{", struct_for, struct_for).unwrap();
+                               writeln!(w, "pub extern \"C\" fn {}_write(obj: &{}) -> crate::c_types::derived::CVec_u8Z {{", struct_for, struct_for).unwrap();
                                writeln!(w, "\tcrate::c_types::serialize_obj(unsafe {{ &(*(*obj).inner) }})").unwrap();
                                writeln!(w, "}}").unwrap();
                                writeln!(w, "#[no_mangle]").unwrap();
@@ -59,22 +59,22 @@ fn convert_macro<W: std::io::Write>(w: &mut W, macro_path: &syn::Path, stream: &
 }
 
 /// Convert "impl trait_path for for_ty { .. }" for manually-mapped types (ie (de)serialization)
-fn maybe_convert_trait_impl<W: std::io::Write>(w: &mut W, trait_path: &syn::Path, for_ty: &syn::Type, types: &mut TypeResolver) {
-       if let Some(t) = types.maybe_resolve_path(&trait_path, None) {
+fn maybe_convert_trait_impl<W: std::io::Write>(w: &mut W, trait_path: &syn::Path, for_ty: &syn::Type, types: &mut TypeResolver, generics: &GenericTypes) {
+       if let Some(t) = types.maybe_resolve_path(&trait_path, Some(generics)) {
                let for_obj;
                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, None));
+                               has_inner = types.c_type_has_inner_from_path(&types.resolve_path(&p.path, Some(generics)));
                        } else { return; }
                } else {
                        // We assume that anything that isn't a Path is somehow a generic that ends up in our
                        // derived-types module.
                        let mut for_obj_vec = Vec::new();
-                       types.write_c_type(&mut for_obj_vec, for_ty, None, false);
+                       types.write_c_type(&mut for_obj_vec, for_ty, Some(generics), false);
                        full_obj_path = String::from_utf8(for_obj_vec).unwrap();
                        assert!(full_obj_path.starts_with(TypeResolver::generated_container_path()));
                        for_obj = full_obj_path[TypeResolver::generated_container_path().len() + 2..].into();
@@ -83,17 +83,17 @@ fn maybe_convert_trait_impl<W: std::io::Write>(w: &mut W, trait_path: &syn::Path
                match &t as &str {
                        "util::ser::Writeable" => {
                                writeln!(w, "#[no_mangle]").unwrap();
-                               writeln!(w, "pub extern \"C\" fn {}_write(obj: *const {}) -> crate::c_types::derived::CVec_u8Z {{", for_obj, full_obj_path).unwrap();
+                               writeln!(w, "pub extern \"C\" fn {}_write(obj: &{}) -> crate::c_types::derived::CVec_u8Z {{", for_obj, full_obj_path).unwrap();
 
                                let ref_type = syn::Type::Reference(syn::TypeReference {
                                        and_token: syn::Token!(&)(Span::call_site()), lifetime: None, mutability: None,
                                        elem: Box::new(for_ty.clone()) });
-                               assert!(!types.write_from_c_conversion_new_var(w, &syn::Ident::new("obj", Span::call_site()), &ref_type, None));
+                               assert!(!types.write_from_c_conversion_new_var(w, &syn::Ident::new("obj", Span::call_site()), &ref_type, Some(generics)));
 
                                write!(w, "\tcrate::c_types::serialize_obj(").unwrap();
-                               types.write_from_c_conversion_prefix(w, &ref_type, None);
+                               types.write_from_c_conversion_prefix(w, &ref_type, Some(generics));
                                write!(w, "unsafe {{ &*obj }}").unwrap();
-                               types.write_from_c_conversion_suffix(w, &ref_type, None);
+                               types.write_from_c_conversion_suffix(w, &ref_type, Some(generics));
                                writeln!(w, ")").unwrap();
 
                                writeln!(w, "}}").unwrap();
@@ -104,7 +104,7 @@ fn maybe_convert_trait_impl<W: std::io::Write>(w: &mut W, trait_path: &syn::Path
                                        writeln!(w, "}}").unwrap();
                                }
                        },
-                       "util::ser::Readable" => {
+                       "util::ser::Readable"|"util::ser::ReadableArgs" => {
                                // Create the Result<Object, DecodeError> syn::Type
                                let mut err_segs = syn::punctuated::Punctuated::new();
                                err_segs.push(syn::PathSegment { ident: syn::Ident::new("ln", Span::call_site()), arguments: syn::PathArguments::None });
@@ -128,17 +128,48 @@ fn maybe_convert_trait_impl<W: std::io::Write>(w: &mut W, trait_path: &syn::Path
                                        leading_colon: None, segments: res_segs } });
 
                                writeln!(w, "#[no_mangle]").unwrap();
-                               write!(w, "pub extern \"C\" fn {}_read(ser: crate::c_types::u8slice) -> ", for_obj).unwrap();
-                               types.write_c_type(w, &res_ty, None, false);
+                               write!(w, "pub extern \"C\" fn {}_read(ser: crate::c_types::u8slice", for_obj).unwrap();
+
+                               let mut arg_conv = Vec::new();
+                               if t == "util::ser::ReadableArgs" {
+                                       write!(w, ", arg: ").unwrap();
+                                       assert!(trait_path.leading_colon.is_none());
+                                       let args_seg = trait_path.segments.iter().last().unwrap();
+                                       assert_eq!(format!("{}", args_seg.ident), "ReadableArgs");
+                                       if let syn::PathArguments::AngleBracketed(args) = &args_seg.arguments {
+                                               assert_eq!(args.args.len(), 1);
+                                               if let syn::GenericArgument::Type(args_ty) = args.args.iter().next().unwrap() {
+                                                       types.write_c_type(w, args_ty, Some(generics), false);
+
+                                                       assert!(!types.write_from_c_conversion_new_var(&mut arg_conv, &syn::Ident::new("arg", Span::call_site()), &args_ty, Some(generics)));
+
+                                                       write!(&mut arg_conv, "\tlet arg_conv = ").unwrap();
+                                                       types.write_from_c_conversion_prefix(&mut arg_conv, &args_ty, Some(generics));
+                                                       write!(&mut arg_conv, "arg").unwrap();
+                                                       types.write_from_c_conversion_suffix(&mut arg_conv, &args_ty, Some(generics));
+                                               } else { unreachable!(); }
+                                       } else { unreachable!(); }
+                               }
+                               write!(w, ") -> ").unwrap();
+                               types.write_c_type(w, &res_ty, Some(generics), false);
                                writeln!(w, " {{").unwrap();
-                               writeln!(w, "\tlet res = crate::c_types::deserialize_obj(ser);").unwrap();
+
+                               if t == "util::ser::ReadableArgs" {
+                                       w.write(&arg_conv).unwrap();
+                                       write!(w, ";\n\tlet res: ").unwrap();
+                                       // At least in one case we need type annotations here, so provide them.
+                                       types.write_rust_type(w, Some(generics), &res_ty);
+                                       writeln!(w, " = crate::c_types::deserialize_obj_arg(ser, arg_conv);").unwrap();
+                               } else {
+                                       writeln!(w, "\tlet res = crate::c_types::deserialize_obj(ser);").unwrap();
+                               }
                                write!(w, "\t").unwrap();
-                               if types.write_to_c_conversion_new_var(w, &syn::Ident::new("res", Span::call_site()), &res_ty, None, false) {
+                               if types.write_to_c_conversion_new_var(w, &syn::Ident::new("res", Span::call_site()), &res_ty, Some(generics), false) {
                                        write!(w, "\n\t").unwrap();
                                }
-                               types.write_to_c_conversion_inline_prefix(w, &res_ty, None, false);
+                               types.write_to_c_conversion_inline_prefix(w, &res_ty, Some(generics), false);
                                write!(w, "res").unwrap();
-                               types.write_to_c_conversion_inline_suffix(w, &res_ty, None, false);
+                               types.write_to_c_conversion_inline_suffix(w, &res_ty, Some(generics), false);
                                writeln!(w, "\n}}").unwrap();
                        },
                        _ => {},
@@ -675,6 +706,35 @@ 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();
+                       if !gen_types.learn_generics(&i.generics, types) {
+                               eprintln!("Not implementing anything for impl tuple due to not understood generics");
+                               return;
+                       }
+
+                       if i.defaultness.is_some() || i.unsafety.is_some() { unimplemented!(); }
+                       if let Some(trait_path) = i.trait_.as_ref() {
+                               if trait_path.0.is_some() { unimplemented!(); }
+                               if types.understood_c_path(&trait_path.1) {
+                                       eprintln!("Not implementing anything for impl Trait for Tuple - we only support manual defines");
+                                       return;
+                               } else {
+                                       // Just do a manual implementation:
+                                       maybe_convert_trait_impl(w, &trait_path.1, &*i.self_ty, types, &gen_types);
+                               }
+                       } else {
+                               eprintln!("Not implementing anything for plain impl tuple block - we only support impl Trait for Tuples");
+                               return;
+                       }
+               }
+       }
        if let &syn::Type::Path(ref p) = &*i.self_ty {
                if p.qself.is_some() { unimplemented!(); }
                if let Some(ident) = single_ident_generic_path_to_ident(&p.path) {
@@ -730,7 +790,7 @@ fn writeln_impl<W: std::io::Write>(w: &mut W, i: &syn::ItemImpl, types: &mut Typ
                                                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();
+                                               write!(w, "#[no_mangle]\npub extern \"C\" fn {}_as_{}(this_arg: &{}) -> 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();
                                                writeln!(w, "\t\tfree: None,").unwrap();
@@ -896,12 +956,11 @@ 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),
-                                                       _ => {},
+                                                       _ => 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);
+                                               maybe_convert_trait_impl(w, &trait_path.1, &*i.self_ty, types, &gen_types);
                                        }
                                } else {
                                        let declared_type = (*types.get_declared_type(&ident).unwrap()).clone();
@@ -1496,10 +1555,18 @@ fn main() {
        let mut cpp_header_file = std::fs::OpenOptions::new().write(true).create(true).truncate(true)
                .open(&args[6]).expect("Unable to open new header file");
 
-       writeln!(header_file, "#if defined(__GNUC__)\n#define MUST_USE_STRUCT __attribute__((warn_unused))").unwrap();
-       writeln!(header_file, "#else\n#define MUST_USE_STRUCT\n#endif").unwrap();
-       writeln!(header_file, "#if defined(__GNUC__)\n#define MUST_USE_RES __attribute__((warn_unused_result))").unwrap();
-       writeln!(header_file, "#else\n#define MUST_USE_RES\n#endif").unwrap();
+       writeln!(header_file, "#if defined(__GNUC__)").unwrap();
+       writeln!(header_file, "#define MUST_USE_STRUCT __attribute__((warn_unused))").unwrap();
+       writeln!(header_file, "#define MUST_USE_RES __attribute__((warn_unused_result))").unwrap();
+       writeln!(header_file, "#else").unwrap();
+       writeln!(header_file, "#define MUST_USE_STRUCT").unwrap();
+       writeln!(header_file, "#define MUST_USE_RES").unwrap();
+       writeln!(header_file, "#endif").unwrap();
+       writeln!(header_file, "#if defined(__clang__)").unwrap();
+       writeln!(header_file, "#define NONNULL_PTR _Nonnull").unwrap();
+       writeln!(header_file, "#else").unwrap();
+       writeln!(header_file, "#define NONNULL_PTR").unwrap();
+       writeln!(header_file, "#endif").unwrap();
        writeln!(cpp_header_file, "#include <string.h>\nnamespace LDK {{").unwrap();
 
        // First parse the full crate's ASTs, caching them so that we can hold references to the AST