[bindings] Drop some stale code from bindings generic generation
[rust-lightning] / c-bindings-gen / src / main.rs
index 6d6296c8f48e93dc661924cf08c239694c74896b..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();
@@ -58,30 +58,119 @@ fn convert_macro<W: std::io::Write>(w: &mut W, macro_path: &syn::Path, stream: &
        }
 }
 
-/// Convert "impl trait_path for for_obj { .. }" for manually-mapped types (ie (de)serialization)
-fn maybe_convert_trait_impl<W: std::io::Write>(w: &mut W, trait_path: &syn::Path, for_obj: &syn::Ident, types: &TypeResolver) {
-       if let Some(t) = types.maybe_resolve_path(&trait_path, None) {
-               let s = types.maybe_resolve_ident(for_obj).unwrap();
-               if !types.crate_types.opaques.get(&s).is_some() { return; }
+/// 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, 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) = 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)));
+                       } 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, 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();
+               }
+
                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, 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, "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, Some(generics)));
+
+                               write!(w, "\tcrate::c_types::serialize_obj(").unwrap();
+                               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, Some(generics));
+                               writeln!(w, ")").unwrap();
+
                                writeln!(w, "}}").unwrap();
+                               if has_inner {
+                                       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" => {
+                       "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 });
+                               err_segs.push(syn::PathSegment { ident: syn::Ident::new("msgs", Span::call_site()), arguments: syn::PathArguments::None });
+                               err_segs.push(syn::PathSegment { ident: syn::Ident::new("DecodeError", Span::call_site()), arguments: syn::PathArguments::None });
+                               let mut args = syn::punctuated::Punctuated::new();
+                               args.push(syn::GenericArgument::Type(for_ty.clone()));
+                               args.push(syn::GenericArgument::Type(syn::Type::Path(syn::TypePath {
+                                       qself: None, path: syn::Path {
+                                               leading_colon: Some(syn::Token![::](Span::call_site())), segments: err_segs,
+                                       }
+                               })));
+                               let mut res_segs = syn::punctuated::Punctuated::new();
+                               res_segs.push(syn::PathSegment {
+                                       ident: syn::Ident::new("Result", Span::call_site()),
+                                       arguments: syn::PathArguments::AngleBracketed(syn::AngleBracketedGenericArguments {
+                                               colon2_token: None, lt_token: syn::Token![<](Span::call_site()), args, gt_token: syn::Token![>](Span::call_site()),
+                                       })
+                               });
+                               let res_ty = syn::Type::Path(syn::TypePath { qself: None, path: syn::Path {
+                                       leading_colon: None, segments: res_segs } });
+
                                writeln!(w, "#[no_mangle]").unwrap();
-                               writeln!(w, "pub extern \"C\" fn {}_read(ser: crate::c_types::u8slice) -> {} {{", for_obj, for_obj).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 }}", for_obj).unwrap();
-                               writeln!(w, "\t}} else {{").unwrap();
-                               writeln!(w, "\t\t{} {{ inner: std::ptr::null_mut(), is_owned: true }}", for_obj).unwrap();
-                               writeln!(w, "\t}}\n}}").unwrap();
+                               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();
+
+                               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, Some(generics), false) {
+                                       write!(w, "\n\t").unwrap();
+                               }
+                               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, Some(generics), false);
+                               writeln!(w, "\n}}").unwrap();
                        },
                        _ => {},
                }
@@ -454,7 +543,7 @@ fn writeln_opaque<W: std::io::Write>(w: &mut W, ident: &syn::Ident, struct_name:
        writeln!(w, "#[allow(unused)]").unwrap();
        writeln!(w, "/// When moving out of the pointer, we have to ensure we aren't a reference, this makes that easy").unwrap();
        writeln!(w, "impl {} {{", struct_name).unwrap();
-       writeln!(w, "\tpub(crate) fn take_ptr(mut self) -> *mut native{} {{", struct_name).unwrap();
+       writeln!(w, "\tpub(crate) fn take_inner(mut self) -> *mut native{} {{", struct_name).unwrap();
        writeln!(w, "\t\tassert!(self.is_owned);").unwrap();
        writeln!(w, "\t\tlet ret = self.inner;").unwrap();
        writeln!(w, "\t\tself.inner = std::ptr::null_mut();").unwrap();
@@ -500,21 +589,28 @@ fn writeln_opaque<W: std::io::Write>(w: &mut W, ident: &syn::Ident, struct_name:
        write_cpp_wrapper(cpp_headers, &format!("{}", ident), true);
 }
 
-/// Writes out all the relevant mappings for a Rust struct, deferring to writeln_opaque to generate
-/// the struct itself, and then writing getters and setters for public, understood-type fields and
-/// a constructor if every field is public.
-fn writeln_struct<'a, 'b, W: std::io::Write>(w: &mut W, s: &'a syn::ItemStruct, types: &mut TypeResolver<'b, 'a>, extra_headers: &mut File, cpp_headers: &mut File) {
-       let struct_name = &format!("{}", s.ident);
+fn declare_struct<'a, 'b>(s: &'a syn::ItemStruct, types: &mut TypeResolver<'b, 'a>) -> bool {
        let export = export_status(&s.attrs);
        match export {
                ExportStatus::Export => {},
-               ExportStatus::TestOnly => return,
+               ExportStatus::TestOnly => return false,
                ExportStatus::NoExport => {
                        types.struct_ignored(&s.ident);
-                       return;
+                       return false;
                }
        }
 
+       types.struct_imported(&s.ident, format!("{}", s.ident));
+       true
+}
+
+/// Writes out all the relevant mappings for a Rust struct, deferring to writeln_opaque to generate
+/// the struct itself, and then writing getters and setters for public, understood-type fields and
+/// a constructor if every field is public.
+fn writeln_struct<'a, 'b, W: std::io::Write>(w: &mut W, s: &'a syn::ItemStruct, types: &mut TypeResolver<'b, 'a>, extra_headers: &mut File, cpp_headers: &mut File) {
+       if !declare_struct(s, types) { return; }
+
+       let struct_name = &format!("{}", s.ident);
        writeln_opaque(w, &s.ident, struct_name, &s.generics, &s.attrs, types, extra_headers, cpp_headers);
 
        eprintln!("exporting fields for {}", struct_name);
@@ -598,8 +694,6 @@ fn writeln_struct<'a, 'b, W: std::io::Write>(w: &mut W, s: &'a syn::ItemStruct,
                        writeln!(w, "\t}})), is_owned: true }}\n}}").unwrap();
                }
        }
-
-       types.struct_imported(&s.ident, struct_name.clone());
 }
 
 /// Prints a relevant conversion for impl *
@@ -612,6 +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) {
@@ -667,7 +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();
@@ -833,12 +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, &ident, 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, &ident, 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();
@@ -916,6 +1038,19 @@ fn is_enum_opaque(e: &syn::ItemEnum) -> bool {
        false
 }
 
+fn declare_enum<'a, 'b>(e: &'a syn::ItemEnum, types: &mut TypeResolver<'b, 'a>) {
+       match export_status(&e.attrs) {
+               ExportStatus::Export => {},
+               ExportStatus::NoExport|ExportStatus::TestOnly => return,
+       }
+
+       if is_enum_opaque(e) {
+               types.enum_ignored(&e.ident);
+       } else {
+               types.mirrored_enum_declared(&e.ident);
+       }
+}
+
 /// Print a mapping of an enum. If all of the enum's fields are C-mapped in some form (or the enum
 /// is unitary), we generate an equivalent enum with all types replaced with their C mapped
 /// versions followed by conversion functions which map between the Rust version and the C mapped
@@ -929,7 +1064,6 @@ fn writeln_enum<'a, 'b, W: std::io::Write>(w: &mut W, e: &'a syn::ItemEnum, type
        if is_enum_opaque(e) {
                eprintln!("Skipping enum {} as it contains non-unit fields", e.ident);
                writeln_opaque(w, &e.ident, &format!("{}", e.ident), &e.generics, &e.attrs, types, extra_headers, cpp_headers);
-               types.enum_ignored(&e.ident);
                return;
        }
        writeln_docs(w, &e.attrs, "");
@@ -937,7 +1071,6 @@ fn writeln_enum<'a, 'b, W: std::io::Write>(w: &mut W, e: &'a syn::ItemEnum, type
        if e.generics.lt_token.is_some() {
                unimplemented!();
        }
-       types.mirrored_enum_declared(&e.ident);
 
        let mut needs_free = false;
 
@@ -1166,9 +1299,27 @@ fn convert_file<'a, 'b>(libast: &'a FullLibraryAST, crate_types: &mut CrateTypes
 
        let mut type_resolver = TypeResolver::new(orig_crate, module, crate_types);
 
+       // First pass over the items and fill in imports and file-declared objects in the type resolver
        for item in syntax.items.iter() {
                match item {
                        syn::Item::Use(u) => type_resolver.process_use(&mut out, &u),
+                       syn::Item::Struct(s) => {
+                               if let syn::Visibility::Public(_) = s.vis {
+                                       declare_struct(&s, &mut type_resolver);
+                               }
+                       },
+                       syn::Item::Enum(e) => {
+                               if let syn::Visibility::Public(_) = e.vis {
+                                       declare_enum(&e, &mut type_resolver);
+                               }
+                       },
+                       _ => {},
+               }
+       }
+
+       for item in syntax.items.iter() {
+               match item {
+                       syn::Item::Use(_) => {}, // Handled above
                        syn::Item::Static(_) => {},
                        syn::Item::Enum(e) => {
                                if let syn::Visibility::Public(_) = e.vis {
@@ -1404,10 +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