1 // This file is Copyright its original authors, visible in version control
4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE>
5 // or the MIT license <LICENSE-MIT>, at your option.
6 // You may not use this file except in accordance with one or both of these
9 //! Converts a rust crate into a rust crate containing a number of C-exported wrapper functions and
10 //! classes (which is exportable using cbindgen).
11 //! In general, supports convering:
12 //! * structs as a pointer to the underlying type (either owned or not owned),
13 //! * traits as a void-ptr plus a jump table,
14 //! * enums as an equivalent enum with all the inner fields mapped to the mapped types,
15 //! * certain containers (tuples, slices, Vecs, Options, and Results currently) to a concrete
16 //! version of a defined container template.
18 //! It also generates relevant memory-management functions and free-standing functions with
19 //! parameters mapped.
21 use std::collections::{HashMap, hash_map};
24 use std::io::{Read, Write};
25 use std::iter::FromIterator;
28 use proc_macro2::Span;
29 use quote::format_ident;
37 const DEFAULT_IMPORTS: &'static str = "
38 use alloc::str::FromStr;
39 use core::ffi::c_void;
40 use core::convert::Infallible;
41 use bitcoin::hashes::Hash;
42 use crate::c_types::*;
43 #[cfg(feature=\"no-std\")]
44 use alloc::{vec::Vec, boxed::Box};
48 /// str.rsplit_once but with an older MSRV
49 fn rsplit_once<'a>(inp: &'a str, pattern: &str) -> Option<(&'a str, &'a str)> {
50 let mut iter = inp.rsplitn(2, pattern);
51 let second_entry = iter.next().unwrap();
52 Some((iter.next().unwrap(), second_entry))
55 // *************************************
56 // *** Manually-expanded conversions ***
57 // *************************************
59 /// Convert "impl trait_path for for_ty { .. }" for manually-mapped types (ie (de)serialization)
60 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) {
61 if let Some(t) = types.maybe_resolve_path(&trait_path, Some(generics)) {
64 let mut has_inner = false;
65 if let syn::Type::Path(ref p) = for_ty {
66 let resolved_path = types.resolve_path(&p.path, Some(generics));
67 for_obj = format!("{}", p.path.segments.last().unwrap().ident);
68 full_obj_path = format!("crate::{}", resolved_path);
69 has_inner = types.c_type_has_inner_from_path(&resolved_path);
71 // We assume that anything that isn't a Path is somehow a generic that ends up in our
72 // derived-types module.
73 let mut for_obj_vec = Vec::new();
74 types.write_c_type(&mut for_obj_vec, for_ty, Some(generics), false);
75 full_obj_path = String::from_utf8(for_obj_vec).unwrap();
76 assert!(full_obj_path.starts_with(TypeResolver::generated_container_path()));
77 for_obj = full_obj_path[TypeResolver::generated_container_path().len() + 2..].into();
81 "lightning::util::ser::Writeable" => {
82 writeln!(w, "#[no_mangle]").unwrap();
83 writeln!(w, "/// Serialize the {} object into a byte array which can be read by {}_read", for_obj, for_obj).unwrap();
84 writeln!(w, "pub extern \"C\" fn {}_write(obj: &{}) -> crate::c_types::derived::CVec_u8Z {{", for_obj, full_obj_path).unwrap();
86 let ref_type: syn::Type = syn::parse_quote!(&#for_ty);
87 assert!(!types.write_from_c_conversion_new_var(w, &format_ident!("obj"), &ref_type, Some(generics)));
89 write!(w, "\tcrate::c_types::serialize_obj(").unwrap();
90 types.write_from_c_conversion_prefix(w, &ref_type, Some(generics));
91 write!(w, "unsafe {{ &*obj }}").unwrap();
92 types.write_from_c_conversion_suffix(w, &ref_type, Some(generics));
93 writeln!(w, ")").unwrap();
95 writeln!(w, "}}").unwrap();
97 writeln!(w, "#[no_mangle]").unwrap();
98 writeln!(w, "pub(crate) extern \"C\" fn {}_write_void(obj: *const c_void) -> crate::c_types::derived::CVec_u8Z {{", for_obj).unwrap();
99 writeln!(w, "\tcrate::c_types::serialize_obj(unsafe {{ &*(obj as *const native{}) }})", for_obj).unwrap();
100 writeln!(w, "}}").unwrap();
103 "lightning::util::ser::Readable"|"lightning::util::ser::ReadableArgs"|"lightning::util::ser::MaybeReadable" => {
104 // Create the Result<Object, DecodeError> syn::Type
105 let mut res_ty: syn::Type = parse_quote!(Result<#for_ty, lightning::ln::msgs::DecodeError>);
107 writeln!(w, "#[no_mangle]").unwrap();
108 writeln!(w, "/// Read a {} from a byte array, created by {}_write", for_obj, for_obj).unwrap();
109 write!(w, "pub extern \"C\" fn {}_read(ser: crate::c_types::u8slice", for_obj).unwrap();
111 let mut arg_conv = Vec::new();
112 if t == "lightning::util::ser::ReadableArgs" {
113 assert!(trait_path.leading_colon.is_none());
114 let args_seg = trait_path.segments.iter().last().unwrap();
115 assert_eq!(format!("{}", args_seg.ident), "ReadableArgs");
116 if let syn::PathArguments::AngleBracketed(args) = &args_seg.arguments {
117 assert_eq!(args.args.len(), 1);
118 if let syn::GenericArgument::Type(args_ty) = args.args.iter().next().unwrap() {
119 macro_rules! write_arg_conv {
120 ($ty: expr, $arg_name: expr) => {
121 write!(w, ", {}: ", $arg_name).unwrap();
122 types.write_c_type(w, $ty, Some(generics), false);
124 write!(&mut arg_conv, "\t").unwrap();
125 if types.write_from_c_conversion_new_var(&mut arg_conv, &format_ident!("{}", $arg_name), &$ty, Some(generics)) {
126 write!(&mut arg_conv, "\n\t").unwrap();
129 write!(&mut arg_conv, "let {}_conv = ", $arg_name).unwrap();
130 types.write_from_c_conversion_prefix(&mut arg_conv, &$ty, Some(generics));
131 write!(&mut arg_conv, "{}", $arg_name).unwrap();
132 types.write_from_c_conversion_suffix(&mut arg_conv, &$ty, Some(generics));
133 write!(&mut arg_conv, ";\n").unwrap();
137 if let syn::Type::Tuple(tup) = args_ty {
138 // Crack open tuples and make them separate arguments instead of
139 // converting the full tuple. This makes it substantially easier to
140 // reason about things like references in the tuple fields.
141 let mut arg_conv_res = Vec::new();
142 for (idx, elem) in tup.elems.iter().enumerate() {
143 let arg_name = format!("arg_{}", ('a' as u8 + idx as u8) as char);
144 write_arg_conv!(elem, arg_name);
145 write!(&mut arg_conv_res, "{}_conv{}", arg_name, if idx != tup.elems.len() - 1 { ", " } else { "" }).unwrap();
147 writeln!(&mut arg_conv, "\tlet arg_conv = ({});", String::from_utf8(arg_conv_res).unwrap()).unwrap();
149 write_arg_conv!(args_ty, "arg");
151 } else { unreachable!(); }
152 } else { unreachable!(); }
153 } else if t == "lightning::util::ser::MaybeReadable" {
154 res_ty = parse_quote!(Result<Option<#for_ty>, lightning::ln::msgs::DecodeError>);
156 write!(w, ") -> ").unwrap();
157 types.write_c_type(w, &res_ty, Some(generics), false);
158 writeln!(w, " {{").unwrap();
160 if t == "lightning::util::ser::ReadableArgs" {
161 w.write(&arg_conv).unwrap();
164 write!(w, "\tlet res: ").unwrap();
165 // At least in one case we need type annotations here, so provide them.
166 types.write_rust_type(w, Some(generics), &res_ty, false);
168 if t == "lightning::util::ser::ReadableArgs" {
169 writeln!(w, " = crate::c_types::deserialize_obj_arg(ser, arg_conv);").unwrap();
170 } else if t == "lightning::util::ser::MaybeReadable" {
171 writeln!(w, " = crate::c_types::maybe_deserialize_obj(ser);").unwrap();
173 writeln!(w, " = crate::c_types::deserialize_obj(ser);").unwrap();
175 write!(w, "\t").unwrap();
176 if types.write_to_c_conversion_new_var(w, &format_ident!("res"), &res_ty, Some(generics), false) {
177 write!(w, "\n\t").unwrap();
179 types.write_to_c_conversion_inline_prefix(w, &res_ty, Some(generics), false);
180 write!(w, "res").unwrap();
181 types.write_to_c_conversion_inline_suffix(w, &res_ty, Some(generics), false);
182 writeln!(w, "\n}}").unwrap();
189 /// Convert "TraitA : TraitB" to a single function name and return type.
191 /// This is (obviously) somewhat over-specialized and only useful for TraitB's that only require a
192 /// single function (eg for serialization).
193 fn convert_trait_impl_field(trait_path: &str) -> (&'static str, String, &'static str) {
195 "lightning::util::ser::Writeable" => ("Serialize the object into a byte array", "write".to_owned(), "crate::c_types::derived::CVec_u8Z"),
196 _ => unimplemented!(),
200 /// Companion to convert_trait_impl_field, write an assignment for the function defined by it for
201 /// `for_obj` which implements the the trait at `trait_path`.
202 fn write_trait_impl_field_assign<W: std::io::Write>(w: &mut W, trait_path: &str, for_obj: &syn::Ident) {
204 "lightning::util::ser::Writeable" => {
205 writeln!(w, "\t\twrite: {}_write_void,", for_obj).unwrap();
207 _ => unimplemented!(),
211 /// Write out the impl block for a defined trait struct which has a supertrait
212 fn do_write_impl_trait<W: std::io::Write>(w: &mut W, trait_path: &str, _trait_name: &syn::Ident, for_obj: &str) {
214 "lightning::util::ser::Writeable" => {
215 writeln!(w, "impl {} for {} {{", trait_path, for_obj).unwrap();
216 writeln!(w, "\tfn write<W: lightning::util::ser::Writer>(&self, w: &mut W) -> Result<(), crate::c_types::io::Error> {{").unwrap();
217 writeln!(w, "\t\tlet vec = (self.write)(self.this_arg);").unwrap();
218 writeln!(w, "\t\tw.write_all(vec.as_slice())").unwrap();
219 writeln!(w, "\t}}\n}}").unwrap();
225 /// Returns true if an instance of the given type must never exist
226 fn is_type_unconstructable(path: &str) -> bool {
227 path == "core::convert::Infallible" || path == "crate::c_types::NotConstructable"
230 // *******************************
231 // *** Per-Type Printing Logic ***
232 // *******************************
234 macro_rules! walk_supertraits { ($t: expr, $types: expr, ($( $($pat: pat)|* => $e: expr),*) ) => { {
235 if $t.colon_token.is_some() {
236 for st in $t.supertraits.iter() {
238 syn::TypeParamBound::Trait(supertrait) => {
239 if supertrait.paren_token.is_some() || supertrait.lifetimes.is_some() {
242 // First try to resolve path to find in-crate traits, but if that doesn't work
243 // assume its a prelude trait (eg Clone, etc) and just use the single ident.
244 let types_opt: Option<&TypeResolver> = $types;
245 if let Some(types) = types_opt {
246 if let Some(path) = types.maybe_resolve_path(&supertrait.path, None) {
247 match (&path as &str, &supertrait.path.segments.iter().last().unwrap().ident) {
248 $( $($pat)|* => $e, )*
253 if let Some(ident) = supertrait.path.get_ident() {
254 match (&format!("{}", ident) as &str, &ident) {
255 $( $($pat)|* => $e, )*
257 } else if types_opt.is_some() {
258 panic!("Supertrait unresolvable and not single-ident");
261 syn::TypeParamBound::Lifetime(_) => unimplemented!(),
267 macro_rules! get_module_type_resolver {
268 ($module: expr, $crate_libs: expr, $crate_types: expr) => { {
269 let module: &str = &$module;
270 let mut module_iter = module.rsplitn(2, "::");
271 module_iter.next().unwrap();
272 let module = module_iter.next().unwrap();
273 let imports = ImportResolver::new(module.splitn(2, "::").next().unwrap(), &$crate_types.lib_ast.dependencies,
274 module, &$crate_types.lib_ast.modules.get(module).unwrap().items);
275 TypeResolver::new(module, imports, $crate_types)
279 /// Prints a C-mapped trait object containing a void pointer and a jump table for each function in
280 /// the original trait.
281 /// Implements the native Rust trait and relevant parent traits for the new C-mapped trait.
283 /// Finally, implements Deref<MappedTrait> for MappedTrait which allows its use in types which need
284 /// a concrete Deref to the Rust trait.
285 fn writeln_trait<'a, 'b, W: std::io::Write>(w: &mut W, t: &'a syn::ItemTrait, types: &mut TypeResolver<'b, 'a>, extra_headers: &mut File, cpp_headers: &mut File) {
286 let trait_name = format!("{}", t.ident);
288 match export_status(&t.attrs) {
289 ExportStatus::Export => { implementable = true; }
290 ExportStatus::NotImplementable => { implementable = false; },
291 ExportStatus::NoExport|ExportStatus::TestOnly => return,
293 writeln_docs(w, &t.attrs, "");
295 let mut gen_types = GenericTypes::new(None);
297 // Add functions which may be required for supertrait implementations.
298 // Due to borrow checker limitations, we only support one in-crate supertrait here.
300 let supertrait_resolver;
301 walk_supertraits!(t, Some(&types), (
303 if let Some(supertrait) = types.crate_types.traits.get(s) {
304 supertrait_name = s.to_string();
305 supertrait_resolver = get_module_type_resolver!(supertrait_name, types.crate_libs, types.crate_types);
306 gen_types.learn_associated_types(&supertrait, &supertrait_resolver);
312 assert!(gen_types.learn_generics(&t.generics, types));
313 gen_types.learn_associated_types(&t, types);
315 writeln!(w, "#[repr(C)]\npub struct {} {{", trait_name).unwrap();
316 writeln!(w, "\t/// An opaque pointer which is passed to your function implementations as an argument.").unwrap();
317 writeln!(w, "\t/// This has no meaning in the LDK, and can be NULL or any other value.").unwrap();
318 writeln!(w, "\tpub this_arg: *mut c_void,").unwrap();
319 // We store every field's (name, Option<clone_fn>, docs) except this_arg, used in Clone generation
320 // docs is only set if its a function which should be callable on the object itself in C++
321 let mut generated_fields = Vec::new();
322 for item in t.items.iter() {
324 &syn::TraitItem::Method(ref m) => {
325 match export_status(&m.attrs) {
326 ExportStatus::NoExport => {
327 // NoExport in this context means we'll hit an unimplemented!() at runtime,
331 ExportStatus::Export => {},
332 ExportStatus::TestOnly => continue,
333 ExportStatus::NotImplementable => panic!("(C-not implementable) must only appear on traits"),
336 let mut meth_gen_types = gen_types.push_ctx();
337 assert!(meth_gen_types.learn_generics(&m.sig.generics, types));
339 writeln_fn_docs(w, &m.attrs, "\t", types, Some(&meth_gen_types), m.sig.inputs.iter(), &m.sig.output);
341 if let syn::ReturnType::Type(_, rtype) = &m.sig.output {
342 if let syn::Type::Reference(r) = &**rtype {
343 // We have to do quite a dance for trait functions which return references
344 // - they ultimately require us to have a native Rust object stored inside
345 // our concrete trait to return a reference to. However, users may wish to
346 // update the value to be returned each time the function is called (or, to
347 // make C copies of Rust impls equivalent, we have to be able to).
349 // Thus, we store a copy of the C-mapped type (which is just a pointer to
350 // the Rust type and a flag to indicate whether deallocation needs to
351 // happen) as well as provide an Option<>al function pointer which is
352 // called when the trait method is called which allows updating on the fly.
353 write!(w, "\tpub {}: ", m.sig.ident).unwrap();
354 generated_fields.push((format!("{}", m.sig.ident), None, None));
355 types.write_c_type(w, &*r.elem, Some(&meth_gen_types), false);
356 writeln!(w, ",").unwrap();
357 writeln!(w, "\t/// Fill in the {} field as a reference to it will be given to Rust after this returns", m.sig.ident).unwrap();
358 writeln!(w, "\t/// Note that this takes a pointer to this object, not the this_ptr like other methods do").unwrap();
359 writeln!(w, "\t/// This function pointer may be NULL if {} is filled in when this object is created and never needs updating.", m.sig.ident).unwrap();
360 writeln!(w, "\tpub set_{}: Option<extern \"C\" fn(&{})>,", m.sig.ident, trait_name).unwrap();
361 generated_fields.push((format!("set_{}", m.sig.ident), None, None));
362 // Note that cbindgen will now generate
363 // typedef struct Thing {..., set_thing: (const struct Thing*), ...} Thing;
364 // which does not compile since Thing is not defined before it is used.
365 writeln!(extra_headers, "struct LDK{};", trait_name).unwrap();
368 // Sadly, this currently doesn't do what we want, but it should be easy to get
369 // cbindgen to support it. See https://github.com/eqrion/cbindgen/issues/531
370 writeln!(w, "\t#[must_use]").unwrap();
373 let mut cpp_docs = Vec::new();
374 writeln_fn_docs(&mut cpp_docs, &m.attrs, "\t * ", types, Some(&meth_gen_types), m.sig.inputs.iter(), &m.sig.output);
375 let docs_string = "\t/**\n".to_owned() + &String::from_utf8(cpp_docs).unwrap().replace("///", "") + "\t */\n";
377 write!(w, "\tpub {}: extern \"C\" fn (", m.sig.ident).unwrap();
378 generated_fields.push((format!("{}", m.sig.ident), None, Some(docs_string)));
379 write_method_params(w, &m.sig, "c_void", types, Some(&meth_gen_types), true, false);
380 writeln!(w, ",").unwrap();
382 &syn::TraitItem::Type(_) => {},
383 _ => unimplemented!(),
386 // Add functions which may be required for supertrait implementations.
387 walk_supertraits!(t, Some(&types), (
389 writeln!(w, "\t/// Called, if set, after this {} has been cloned into a duplicate object.", trait_name).unwrap();
390 writeln!(w, "\t/// The new {} is provided, and should be mutated as needed to perform a", trait_name).unwrap();
391 writeln!(w, "\t/// deep copy of the object pointed to by this_arg or avoid any double-freeing.").unwrap();
392 writeln!(w, "\tpub cloned: Option<extern \"C\" fn (new_{}: &mut {})>,", trait_name, trait_name).unwrap();
393 generated_fields.push(("cloned".to_owned(), None, None));
395 ("std::cmp::Eq", _)|("core::cmp::Eq", _) => {
396 let eq_docs = "Checks if two objects are equal given this object's this_arg pointer and another object.";
397 writeln!(w, "\t/// {}", eq_docs).unwrap();
398 writeln!(w, "\tpub eq: extern \"C\" fn (this_arg: *const c_void, other_arg: &{}) -> bool,", trait_name).unwrap();
399 generated_fields.push(("eq".to_owned(), None, Some(format!("\t/** {} */\n", eq_docs))));
401 ("std::hash::Hash", _)|("core::hash::Hash", _) => {
402 let hash_docs_a = "Calculate a succinct non-cryptographic hash for an object given its this_arg pointer.";
403 let hash_docs_b = "This is used, for example, for inclusion of this object in a hash map.";
404 writeln!(w, "\t/// {}", hash_docs_a).unwrap();
405 writeln!(w, "\t/// {}", hash_docs_b).unwrap();
406 writeln!(w, "\tpub hash: extern \"C\" fn (this_arg: *const c_void) -> u64,").unwrap();
407 generated_fields.push(("hash".to_owned(), None,
408 Some(format!("\t/**\n\t * {}\n\t * {}\n\t */\n", hash_docs_a, hash_docs_b))));
410 ("Send", _) => {}, ("Sync", _) => {},
411 ("std::fmt::Debug", _)|("core::fmt::Debug", _) => {
412 let debug_docs = "Return a human-readable \"debug\" string describing this object";
413 writeln!(w, "\t/// {}", debug_docs).unwrap();
414 writeln!(w, "\tpub debug_str: extern \"C\" fn (this_arg: *const c_void) -> crate::c_types::Str,").unwrap();
415 generated_fields.push(("debug_str".to_owned(), None,
416 Some(format!("\t/**\n\t * {}\n\t */\n", debug_docs))));
419 // TODO: Both of the below should expose supertrait methods in C++, but doing so is
421 generated_fields.push(if types.crate_types.traits.get(s).is_none() {
422 let (docs, name, ret) = convert_trait_impl_field(s);
423 writeln!(w, "\t/// {}", docs).unwrap();
424 writeln!(w, "\tpub {}: extern \"C\" fn (this_arg: *const c_void) -> {},", name, ret).unwrap();
425 (name, None, None) // Assume clonable
427 // For in-crate supertraits, just store a C-mapped copy of the supertrait as a member.
428 writeln!(w, "\t/// Implementation of {} for this object.", i).unwrap();
429 let is_clonable = types.is_clonable(s);
430 writeln!(w, "\tpub {}: crate::{},", i, s).unwrap();
431 (format!("{}", i), if !is_clonable {
432 Some(format!("crate::{}_clone_fields", s))
433 } else { None }, None)
437 writeln!(w, "\t/// Frees any resources associated with this object given its this_arg pointer.").unwrap();
438 writeln!(w, "\t/// Does not need to free the outer struct containing function pointers and may be NULL is no resources need to be freed.").unwrap();
439 writeln!(w, "\tpub free: Option<extern \"C\" fn(this_arg: *mut c_void)>,").unwrap();
440 generated_fields.push(("free".to_owned(), None, None));
441 writeln!(w, "}}").unwrap();
443 macro_rules! impl_trait_for_c {
444 ($t: expr, $impl_accessor: expr, $type_resolver: expr) => {
445 for item in $t.items.iter() {
447 syn::TraitItem::Method(m) => {
448 if let ExportStatus::TestOnly = export_status(&m.attrs) { continue; }
449 if m.sig.constness.is_some() || m.sig.asyncness.is_some() || m.sig.unsafety.is_some() ||
450 m.sig.abi.is_some() || m.sig.variadic.is_some() {
453 let mut meth_gen_types = gen_types.push_ctx();
454 assert!(meth_gen_types.learn_generics(&m.sig.generics, $type_resolver));
455 // Note that we do *not* use the method generics when printing "native"
456 // rust parts - if the method is generic, we need to print a generic
458 write!(w, "\tfn {}", m.sig.ident).unwrap();
459 $type_resolver.write_rust_generic_param(w, Some(&gen_types), m.sig.generics.params.iter());
460 write!(w, "(").unwrap();
461 for inp in m.sig.inputs.iter() {
463 syn::FnArg::Receiver(recv) => {
464 if !recv.attrs.is_empty() || recv.reference.is_none() { panic!("2"); }
465 write!(w, "&").unwrap();
466 if let Some(lft) = &recv.reference.as_ref().unwrap().1 {
467 write!(w, "'{} ", lft.ident).unwrap();
469 if recv.mutability.is_some() {
470 write!(w, "mut self").unwrap();
472 write!(w, "self").unwrap();
475 syn::FnArg::Typed(arg) => {
476 if !arg.attrs.is_empty() { panic!("3"); }
478 syn::Pat::Ident(ident) => {
479 if !ident.attrs.is_empty() || ident.by_ref.is_some() ||
480 ident.mutability.is_some() || ident.subpat.is_some() {
483 write!(w, ", mut {}{}: ", if $type_resolver.skip_arg(&*arg.ty, Some(&meth_gen_types)) { "_" } else { "" }, ident.ident).unwrap();
487 $type_resolver.write_rust_type(w, Some(&gen_types), &*arg.ty, false);
491 write!(w, ")").unwrap();
492 match &m.sig.output {
493 syn::ReturnType::Type(_, rtype) => {
494 write!(w, " -> ").unwrap();
495 $type_resolver.write_rust_type(w, Some(&gen_types), &*rtype, false)
499 write!(w, " {{\n\t\t").unwrap();
500 match export_status(&m.attrs) {
501 ExportStatus::NoExport => {
506 if let syn::ReturnType::Type(_, rtype) = &m.sig.output {
507 if let syn::Type::Reference(r) = &**rtype {
508 assert_eq!(m.sig.inputs.len(), 1); // Must only take self!
509 writeln!(w, "if let Some(f) = self{}.set_{} {{", $impl_accessor, m.sig.ident).unwrap();
510 writeln!(w, "\t\t\t(f)(&self{});", $impl_accessor).unwrap();
511 write!(w, "\t\t}}\n\t\t").unwrap();
512 $type_resolver.write_from_c_conversion_to_ref_prefix(w, &*r.elem, Some(&meth_gen_types));
513 write!(w, "self{}.{}", $impl_accessor, m.sig.ident).unwrap();
514 $type_resolver.write_from_c_conversion_to_ref_suffix(w, &*r.elem, Some(&meth_gen_types));
515 writeln!(w, "\n\t}}").unwrap();
519 write_method_var_decl_body(w, &m.sig, "\t", $type_resolver, Some(&meth_gen_types), true);
520 write!(w, "(self{}.{})(", $impl_accessor, m.sig.ident).unwrap();
521 let mut args = Vec::new();
522 write_method_call_params(&mut args, &m.sig, "\t", $type_resolver, Some(&meth_gen_types), "", true);
523 w.write_all(String::from_utf8(args).unwrap().replace("self", &format!("self{}", $impl_accessor)).as_bytes()).unwrap();
525 writeln!(w, "\n\t}}").unwrap();
527 &syn::TraitItem::Type(ref t) => {
528 if t.default.is_some() || t.generics.lt_token.is_some() { panic!("10"); }
529 let mut bounds_iter = t.bounds.iter();
531 match bounds_iter.next().unwrap() {
532 syn::TypeParamBound::Trait(tr) => {
533 writeln!(w, "\ttype {} = crate::{};", t.ident, $type_resolver.resolve_path(&tr.path, Some(&gen_types))).unwrap();
534 for bound in bounds_iter {
535 if let syn::TypeParamBound::Trait(_) = bound { panic!("11"); }
539 syn::TypeParamBound::Lifetime(_) => {},
549 writeln!(w, "unsafe impl Send for {} {{}}", trait_name).unwrap();
550 writeln!(w, "unsafe impl Sync for {} {{}}", trait_name).unwrap();
552 writeln!(w, "#[no_mangle]").unwrap();
553 writeln!(w, "pub(crate) extern \"C\" fn {}_clone_fields(orig: &{}) -> {} {{", trait_name, trait_name, trait_name).unwrap();
554 writeln!(w, "\t{} {{", trait_name).unwrap();
555 writeln!(w, "\t\tthis_arg: orig.this_arg,").unwrap();
556 for (field, clone_fn, _) in generated_fields.iter() {
557 if let Some(f) = clone_fn {
558 // If the field isn't clonable, blindly assume its a trait and hope for the best.
559 writeln!(w, "\t\t{}: {}(&orig.{}),", field, f, field).unwrap();
561 writeln!(w, "\t\t{}: Clone::clone(&orig.{}),", field, field).unwrap();
564 writeln!(w, "\t}}\n}}").unwrap();
566 // Implement supertraits for the C-mapped struct.
567 walk_supertraits!(t, Some(&types), (
568 ("std::cmp::Eq", _)|("core::cmp::Eq", _) => {
569 writeln!(w, "impl core::cmp::Eq for {} {{}}", trait_name).unwrap();
570 writeln!(w, "impl core::cmp::PartialEq for {} {{", trait_name).unwrap();
571 writeln!(w, "\tfn eq(&self, o: &Self) -> bool {{ (self.eq)(self.this_arg, o) }}\n}}").unwrap();
573 ("std::hash::Hash", _)|("core::hash::Hash", _) => {
574 writeln!(w, "impl core::hash::Hash for {} {{", trait_name).unwrap();
575 writeln!(w, "\tfn hash<H: core::hash::Hasher>(&self, hasher: &mut H) {{ hasher.write_u64((self.hash)(self.this_arg)) }}\n}}").unwrap();
577 ("Send", _) => {}, ("Sync", _) => {},
579 writeln!(w, "#[no_mangle]").unwrap();
580 writeln!(w, "/// Creates a copy of a {}", trait_name).unwrap();
581 writeln!(w, "pub extern \"C\" fn {}_clone(orig: &{}) -> {} {{", trait_name, trait_name, trait_name).unwrap();
582 writeln!(w, "\tlet mut res = {}_clone_fields(orig);", trait_name).unwrap();
583 writeln!(w, "\tif let Some(f) = orig.cloned {{ (f)(&mut res) }};").unwrap();
584 writeln!(w, "\tres\n}}").unwrap();
585 writeln!(w, "impl Clone for {} {{", trait_name).unwrap();
586 writeln!(w, "\tfn clone(&self) -> Self {{").unwrap();
587 writeln!(w, "\t\t{}_clone(self)", trait_name).unwrap();
588 writeln!(w, "\t}}\n}}").unwrap();
590 ("std::fmt::Debug", _)|("core::fmt::Debug", _) => {
591 writeln!(w, "impl core::fmt::Debug for {} {{", trait_name).unwrap();
592 writeln!(w, "\tfn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {{").unwrap();
593 writeln!(w, "\t\tf.write_str((self.debug_str)(self.this_arg).into_str())").unwrap();
594 writeln!(w, "\t}}").unwrap();
595 writeln!(w, "}}").unwrap();
598 if let Some(supertrait) = types.crate_types.traits.get(s) {
599 let resolver = get_module_type_resolver!(s, types.crate_libs, types.crate_types);
601 // Blindly assume that the same imports where `supertrait` is defined are also
602 // imported here. This will almost certainly break at some point, but it should be
603 // a compilation failure when it does so.
604 write!(w, "impl").unwrap();
605 maybe_write_lifetime_generics(w, &supertrait.generics, types);
606 write!(w, " {}", s).unwrap();
607 maybe_write_generics(w, &supertrait.generics, types, false);
608 writeln!(w, " for {} {{", trait_name).unwrap();
610 impl_trait_for_c!(supertrait, format!(".{}", i), &resolver);
611 writeln!(w, "}}").unwrap();
613 do_write_impl_trait(w, s, i, &trait_name);
618 // Finally, implement the original Rust trait for the newly created mapped trait.
619 writeln!(w, "\nuse {}::{} as rust{};", types.module_path, t.ident, trait_name).unwrap();
621 write!(w, "impl").unwrap();
622 maybe_write_lifetime_generics(w, &t.generics, types);
623 write!(w, " rust{}", t.ident).unwrap();
624 maybe_write_generics(w, &t.generics, types, false);
625 writeln!(w, " for {} {{", trait_name).unwrap();
626 impl_trait_for_c!(t, "", types);
627 writeln!(w, "}}\n").unwrap();
628 writeln!(w, "// We're essentially a pointer already, or at least a set of pointers, so allow us to be used").unwrap();
629 writeln!(w, "// directly as a Deref trait in higher-level structs:").unwrap();
630 writeln!(w, "impl core::ops::Deref for {} {{\n\ttype Target = Self;", trait_name).unwrap();
631 writeln!(w, "\tfn deref(&self) -> &Self {{\n\t\tself\n\t}}\n}}").unwrap();
634 writeln!(w, "/// Calls the free function if one is set").unwrap();
635 writeln!(w, "#[no_mangle]\npub extern \"C\" fn {}_free(this_ptr: {}) {{ }}", trait_name, trait_name).unwrap();
636 writeln!(w, "impl Drop for {} {{", trait_name).unwrap();
637 writeln!(w, "\tfn drop(&mut self) {{").unwrap();
638 writeln!(w, "\t\tif let Some(f) = self.free {{").unwrap();
639 writeln!(w, "\t\t\tf(self.this_arg);").unwrap();
640 writeln!(w, "\t\t}}\n\t}}\n}}").unwrap();
642 write_cpp_wrapper(cpp_headers, &trait_name, true, Some(generated_fields.drain(..)
643 .filter_map(|(name, _, docs)| if let Some(docs) = docs { Some((name, docs)) } else { None }).collect()));
646 /// Write out a simple "opaque" type (eg structs) which contain a pointer to the native Rust type
647 /// and a flag to indicate whether Drop'ing the mapped struct drops the underlying Rust type.
649 /// Also writes out a _free function and a C++ wrapper which handles calling _free.
650 fn writeln_opaque<W: std::io::Write>(w: &mut W, ident: &syn::Ident, struct_name: &str, generics: &syn::Generics, attrs: &[syn::Attribute], types: &TypeResolver, extra_headers: &mut File, cpp_headers: &mut File) {
651 // If we directly read the original type by its original name, cbindgen hits
652 // https://github.com/eqrion/cbindgen/issues/286 Thus, instead, we import it as a temporary
653 // name and then reference it by that name, which works around the issue.
654 write!(w, "\nuse {}::{} as native{}Import;\npub(crate) type native{} = native{}Import", types.module_path, ident, ident, ident, ident).unwrap();
655 maybe_write_generics(w, &generics, &types, true);
656 writeln!(w, ";\n").unwrap();
657 writeln!(extra_headers, "struct native{}Opaque;\ntypedef struct native{}Opaque LDKnative{};", ident, ident, ident).unwrap();
658 writeln_docs(w, &attrs, "");
659 writeln!(w, "#[must_use]\n#[repr(C)]\npub struct {} {{", struct_name).unwrap();
660 writeln!(w, "\t/// A pointer to the opaque Rust object.\n").unwrap();
661 writeln!(w, "\t/// Nearly everywhere, inner must be non-null, however in places where").unwrap();
662 writeln!(w, "\t/// the Rust equivalent takes an Option, it may be set to null to indicate None.").unwrap();
663 writeln!(w, "\tpub inner: *mut native{},", ident).unwrap();
664 writeln!(w, "\t/// Indicates that this is the only struct which contains the same pointer.\n").unwrap();
665 writeln!(w, "\t/// Rust functions which take ownership of an object provided via an argument require").unwrap();
666 writeln!(w, "\t/// this to be true and invalidate the object pointed to by inner.").unwrap();
667 writeln!(w, "\tpub is_owned: bool,").unwrap();
668 writeln!(w, "}}\n").unwrap();
669 writeln!(w, "impl Drop for {} {{\n\tfn drop(&mut self) {{", struct_name).unwrap();
670 writeln!(w, "\t\tif self.is_owned && !<*mut native{}>::is_null(self.inner) {{", ident).unwrap();
671 writeln!(w, "\t\t\tlet _ = unsafe {{ Box::from_raw(ObjOps::untweak_ptr(self.inner)) }};\n\t\t}}\n\t}}\n}}").unwrap();
672 writeln!(w, "/// Frees any resources used by the {}, if is_owned is set and inner is non-NULL.", struct_name).unwrap();
673 writeln!(w, "#[no_mangle]\npub extern \"C\" fn {}_free(this_obj: {}) {{ }}", struct_name, struct_name).unwrap();
674 writeln!(w, "#[allow(unused)]").unwrap();
675 writeln!(w, "/// Used only if an object of this type is returned as a trait impl by a method").unwrap();
676 writeln!(w, "pub(crate) extern \"C\" fn {}_free_void(this_ptr: *mut c_void) {{", struct_name).unwrap();
677 writeln!(w, "\tunsafe {{ let _ = Box::from_raw(this_ptr as *mut native{}); }}\n}}", struct_name).unwrap();
678 writeln!(w, "#[allow(unused)]").unwrap();
679 writeln!(w, "impl {} {{", struct_name).unwrap();
680 writeln!(w, "\tpub(crate) fn get_native_ref(&self) -> &'static native{} {{", struct_name).unwrap();
681 writeln!(w, "\t\tunsafe {{ &*ObjOps::untweak_ptr(self.inner) }}").unwrap();
682 writeln!(w, "\t}}").unwrap();
683 writeln!(w, "\tpub(crate) fn get_native_mut_ref(&self) -> &'static mut native{} {{", struct_name).unwrap();
684 writeln!(w, "\t\tunsafe {{ &mut *ObjOps::untweak_ptr(self.inner) }}").unwrap();
685 writeln!(w, "\t}}").unwrap();
686 writeln!(w, "\t/// When moving out of the pointer, we have to ensure we aren't a reference, this makes that easy").unwrap();
687 writeln!(w, "\tpub(crate) fn take_inner(mut self) -> *mut native{} {{", struct_name).unwrap();
688 writeln!(w, "\t\tassert!(self.is_owned);").unwrap();
689 writeln!(w, "\t\tlet ret = ObjOps::untweak_ptr(self.inner);").unwrap();
690 writeln!(w, "\t\tself.inner = core::ptr::null_mut();").unwrap();
691 writeln!(w, "\t\tret").unwrap();
692 writeln!(w, "\t}}\n}}").unwrap();
694 write_cpp_wrapper(cpp_headers, &format!("{}", ident), true, None);
697 /// Writes out all the relevant mappings for a Rust struct, deferring to writeln_opaque to generate
698 /// the struct itself, and then writing getters and setters for public, understood-type fields and
699 /// a constructor if every field is public.
700 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) {
701 if export_status(&s.attrs) != ExportStatus::Export { return; }
703 let struct_name = &format!("{}", s.ident);
704 writeln_opaque(w, &s.ident, struct_name, &s.generics, &s.attrs, types, extra_headers, cpp_headers);
706 let mut self_path_segs = syn::punctuated::Punctuated::new();
707 self_path_segs.push(s.ident.clone().into());
708 let self_path = syn::Path { leading_colon: None, segments: self_path_segs};
709 let mut gen_types = GenericTypes::new(Some(types.resolve_path(&self_path, None)));
710 assert!(gen_types.learn_generics(&s.generics, types));
712 let mut all_fields_settable = true;
713 macro_rules! define_field {
714 ($new_name: expr, $real_name: expr, $field: expr) => {
715 if let syn::Visibility::Public(_) = $field.vis {
716 let export = export_status(&$field.attrs);
718 ExportStatus::Export => {},
719 ExportStatus::NoExport|ExportStatus::TestOnly => {
720 all_fields_settable = false;
723 ExportStatus::NotImplementable => panic!("(C-not implementable) must only appear on traits"),
726 if let Some(ref_type) = types.create_ownable_reference(&$field.ty, Some(&gen_types)) {
727 if types.understood_c_type(&ref_type, Some(&gen_types)) {
728 writeln_arg_docs(w, &$field.attrs, "", types, Some(&gen_types), vec![].drain(..), Some(&ref_type));
729 write!(w, "#[no_mangle]\npub extern \"C\" fn {}_get_{}(this_ptr: &{}) -> ", struct_name, $new_name, struct_name).unwrap();
730 types.write_c_type(w, &ref_type, Some(&gen_types), true);
731 write!(w, " {{\n\tlet mut inner_val = &mut this_ptr.get_native_mut_ref().{};\n\t", $real_name).unwrap();
732 let local_var = types.write_to_c_conversion_from_ownable_ref_new_var(w, &format_ident!("inner_val"), &ref_type, Some(&gen_types));
733 if local_var { write!(w, "\n\t").unwrap(); }
734 types.write_to_c_conversion_inline_prefix(w, &ref_type, Some(&gen_types), true);
735 write!(w, "inner_val").unwrap();
736 types.write_to_c_conversion_inline_suffix(w, &ref_type, Some(&gen_types), true);
737 writeln!(w, "\n}}").unwrap();
739 // If the type isn't reference-able, but is clonable, export a getter that just clones
740 if types.understood_c_type(&$field.ty, Some(&gen_types)) {
741 let mut v = Vec::new();
742 types.write_c_type(&mut v, &$field.ty, Some(&gen_types), true);
743 let s = String::from_utf8(v).unwrap();
744 if types.is_clonable(&s) {
745 writeln_arg_docs(w, &$field.attrs, "", types, Some(&gen_types), vec![].drain(..), Some(&$field.ty));
746 writeln!(w, "///\n/// Returns a copy of the field.").unwrap();
747 write!(w, "#[no_mangle]\npub extern \"C\" fn {}_get_{}(this_ptr: &{}) -> {}", struct_name, $new_name, struct_name, s).unwrap();
748 write!(w, " {{\n\tlet mut inner_val = this_ptr.get_native_mut_ref().{}.clone();\n\t", $real_name).unwrap();
749 let local_var = types.write_to_c_conversion_new_var(w, &format_ident!("inner_val"), &$field.ty, Some(&gen_types), true);
750 if local_var { write!(w, "\n\t").unwrap(); }
751 types.write_to_c_conversion_inline_prefix(w, &$field.ty, Some(&gen_types), true);
752 write!(w, "inner_val").unwrap();
753 types.write_to_c_conversion_inline_suffix(w, &$field.ty, Some(&gen_types), true);
754 writeln!(w, "\n}}").unwrap();
760 if types.understood_c_type(&$field.ty, Some(&gen_types)) {
761 writeln_arg_docs(w, &$field.attrs, "", types, Some(&gen_types), vec![("val".to_owned(), &$field.ty)].drain(..), None);
762 write!(w, "#[no_mangle]\npub extern \"C\" fn {}_set_{}(this_ptr: &mut {}, mut val: ", struct_name, $new_name, struct_name).unwrap();
763 types.write_c_type(w, &$field.ty, Some(&gen_types), false);
764 write!(w, ") {{\n\t").unwrap();
765 let local_var = types.write_from_c_conversion_new_var(w, &format_ident!("val"), &$field.ty, Some(&gen_types));
766 if local_var { write!(w, "\n\t").unwrap(); }
767 write!(w, "unsafe {{ &mut *ObjOps::untweak_ptr(this_ptr.inner) }}.{} = ", $real_name).unwrap();
768 types.write_from_c_conversion_prefix(w, &$field.ty, Some(&gen_types));
769 write!(w, "val").unwrap();
770 types.write_from_c_conversion_suffix(w, &$field.ty, Some(&gen_types));
771 writeln!(w, ";\n}}").unwrap();
772 } else { all_fields_settable = false; }
773 } else { all_fields_settable = false; }
778 syn::Fields::Named(fields) => {
779 for field in fields.named.iter() {
780 if let Some(ident) = &field.ident {
781 define_field!(ident, ident, field);
782 } else { all_fields_settable = false; }
785 syn::Fields::Unnamed(fields) => {
786 for (idx, field) in fields.unnamed.iter().enumerate() {
787 define_field!(('a' as u8 + idx as u8) as char, ('0' as u8 + idx as u8) as char, field);
790 _ => unimplemented!()
793 if all_fields_settable {
794 // Build a constructor!
795 writeln!(w, "/// Constructs a new {} given each field", struct_name).unwrap();
796 write!(w, "#[must_use]\n#[no_mangle]\npub extern \"C\" fn {}_new(", struct_name).unwrap();
799 syn::Fields::Named(fields) => {
800 for (idx, field) in fields.named.iter().enumerate() {
801 if idx != 0 { write!(w, ", ").unwrap(); }
802 write!(w, "mut {}_arg: ", field.ident.as_ref().unwrap()).unwrap();
803 types.write_c_type(w, &field.ty, Some(&gen_types), false);
806 syn::Fields::Unnamed(fields) => {
807 for (idx, field) in fields.unnamed.iter().enumerate() {
808 if idx != 0 { write!(w, ", ").unwrap(); }
809 write!(w, "mut {}_arg: ", ('a' as u8 + idx as u8) as char).unwrap();
810 types.write_c_type(w, &field.ty, Some(&gen_types), false);
815 write!(w, ") -> {} {{\n\t", struct_name).unwrap();
817 syn::Fields::Named(fields) => {
818 for field in fields.named.iter() {
819 let field_ident = format_ident!("{}_arg", field.ident.as_ref().unwrap());
820 if types.write_from_c_conversion_new_var(w, &field_ident, &field.ty, Some(&gen_types)) {
821 write!(w, "\n\t").unwrap();
825 syn::Fields::Unnamed(fields) => {
826 for (idx, field) in fields.unnamed.iter().enumerate() {
827 let field_ident = format_ident!("{}_arg", ('a' as u8 + idx as u8) as char);
828 if types.write_from_c_conversion_new_var(w, &field_ident, &field.ty, Some(&gen_types)) {
829 write!(w, "\n\t").unwrap();
835 write!(w, "{} {{ inner: ObjOps::heap_alloc(", struct_name).unwrap();
837 syn::Fields::Named(fields) => {
838 writeln!(w, "native{} {{", s.ident).unwrap();
839 for field in fields.named.iter() {
840 write!(w, "\t\t{}: ", field.ident.as_ref().unwrap()).unwrap();
841 types.write_from_c_conversion_prefix(w, &field.ty, Some(&gen_types));
842 write!(w, "{}_arg", field.ident.as_ref().unwrap()).unwrap();
843 types.write_from_c_conversion_suffix(w, &field.ty, Some(&gen_types));
844 writeln!(w, ",").unwrap();
846 write!(w, "\t}}").unwrap();
848 syn::Fields::Unnamed(fields) => {
849 assert!(s.generics.lt_token.is_none());
850 writeln!(w, "{} (", types.maybe_resolve_ident(&s.ident).unwrap()).unwrap();
851 for (idx, field) in fields.unnamed.iter().enumerate() {
852 write!(w, "\t\t").unwrap();
853 types.write_from_c_conversion_prefix(w, &field.ty, Some(&gen_types));
854 write!(w, "{}_arg", ('a' as u8 + idx as u8) as char).unwrap();
855 types.write_from_c_conversion_suffix(w, &field.ty, Some(&gen_types));
856 writeln!(w, ",").unwrap();
858 write!(w, "\t)").unwrap();
862 writeln!(w, "), is_owned: true }}\n}}").unwrap();
866 /// Prints a relevant conversion for impl *
868 /// For simple impl Struct {}s, this just outputs the wrapper functions as Struct_fn_name() { .. }.
870 /// For impl Trait for Struct{}s, this non-exported generates wrapper functions as
871 /// Trait_Struct_fn_name and a Struct_as_Trait(&struct) -> Trait function which returns a populated
872 /// Trait struct containing a pointer to the passed struct's inner field and the wrapper functions.
874 /// A few non-crate Traits are hard-coded including Default.
875 fn writeln_impl<W: std::io::Write>(w: &mut W, i: &syn::ItemImpl, types: &mut TypeResolver) {
876 match export_status(&i.attrs) {
877 ExportStatus::Export => {},
878 ExportStatus::NoExport|ExportStatus::TestOnly => return,
879 ExportStatus::NotImplementable => panic!("(C-not implementable) must only appear on traits"),
882 if let syn::Type::Tuple(_) = &*i.self_ty {
883 if types.understood_c_type(&*i.self_ty, None) {
884 let mut gen_types = GenericTypes::new(None);
885 if !gen_types.learn_generics(&i.generics, types) {
886 eprintln!("Not implementing anything for `impl (..)` due to not understood generics");
890 if i.defaultness.is_some() || i.unsafety.is_some() { unimplemented!(); }
891 if let Some(trait_path) = i.trait_.as_ref() {
892 if trait_path.0.is_some() { unimplemented!(); }
893 if types.understood_c_path(&trait_path.1) {
894 eprintln!("Not implementing anything for `impl Trait for (..)` - we only support manual defines");
897 // Just do a manual implementation:
898 maybe_convert_trait_impl(w, &trait_path.1, &*i.self_ty, types, &gen_types);
901 eprintln!("Not implementing anything for plain `impl (..)` block - we only support `impl Trait for (..)` blocks");
907 if let &syn::Type::Path(ref p) = &*i.self_ty {
908 if p.qself.is_some() { unimplemented!(); }
909 let ident = &p.path.segments.last().unwrap().ident;
910 if let Some(resolved_path) = types.maybe_resolve_path(&p.path, None) {
911 if types.crate_types.opaques.contains_key(&resolved_path) || types.crate_types.mirrored_enums.contains_key(&resolved_path) ||
912 // At least for core::infallible::Infallible we need to support mapping an
913 // out-of-crate trait implementation.
914 (types.understood_c_path(&p.path) && first_seg_is_stdlib(resolved_path.split("::").next().unwrap())) {
915 if !types.understood_c_path(&p.path) {
916 eprintln!("Not implementing anything for impl {} as the type is not understood (probably C-not exported)", ident);
920 let mut gen_types = GenericTypes::new(Some(resolved_path.clone()));
921 if !gen_types.learn_generics(&i.generics, types) {
922 eprintln!("Not implementing anything for impl {} due to not understood generics", ident);
926 if i.defaultness.is_some() || i.unsafety.is_some() { unimplemented!(); }
927 if let Some(trait_path) = i.trait_.as_ref() {
928 if trait_path.0.is_some() { unimplemented!(); }
929 if types.understood_c_path(&trait_path.1) {
930 let full_trait_path = types.resolve_path(&trait_path.1, None);
931 let trait_obj = *types.crate_types.traits.get(&full_trait_path).unwrap();
934 let supertrait_resolver;
935 walk_supertraits!(trait_obj, Some(&types), (
937 if let Some(supertrait) = types.crate_types.traits.get(s) {
938 supertrait_name = s.to_string();
939 supertrait_resolver = get_module_type_resolver!(supertrait_name, types.crate_libs, types.crate_types);
940 gen_types.learn_associated_types(&supertrait, &supertrait_resolver);
945 // We learn the associated types maping from the original trait object.
946 // That's great, except that they are unresolved idents, so if we learn
947 // mappings from a trai defined in a different file, we may mis-resolve or
948 // fail to resolve the mapped types. Thus, we have to construct a new
949 // resolver for the module that the trait was defined in here first.
950 let mut trait_resolver = get_module_type_resolver!(full_trait_path, types.crate_libs, types.crate_types);
951 gen_types.learn_associated_types(trait_obj, &trait_resolver);
952 let mut impl_associated_types = HashMap::new();
953 for item in i.items.iter() {
955 syn::ImplItem::Type(t) => {
956 if let syn::Type::Path(p) = &t.ty {
957 if let Some(id) = single_ident_generic_path_to_ident(&p.path) {
958 impl_associated_types.insert(&t.ident, id);
966 let export = export_status(&trait_obj.attrs);
968 ExportStatus::Export|ExportStatus::NotImplementable => {},
969 ExportStatus::NoExport|ExportStatus::TestOnly => return,
972 // For cases where we have a concrete native object which implements a
973 // trait and need to return the C-mapped version of the trait, provide a
974 // From<> implementation which does all the work to ensure free is handled
975 // properly. This way we can call this method from deep in the
976 // type-conversion logic without actually knowing the concrete native type.
977 if !resolved_path.starts_with(types.module_path) {
978 if !first_seg_is_stdlib(resolved_path.split("::").next().unwrap()) {
979 writeln!(w, "use crate::{}::native{} as native{};", resolved_path.rsplitn(2, "::").skip(1).next().unwrap(), ident, ident).unwrap();
980 writeln!(w, "use crate::{};", resolved_path).unwrap();
981 writeln!(w, "use crate::{}_free_void;", resolved_path).unwrap();
983 writeln!(w, "use {} as native{};", resolved_path, ident).unwrap();
986 writeln!(w, "impl From<native{}> for crate::{} {{", ident, full_trait_path).unwrap();
987 writeln!(w, "\tfn from(obj: native{}) -> Self {{", ident).unwrap();
988 if is_type_unconstructable(&resolved_path) {
989 writeln!(w, "\t\tunreachable!();").unwrap();
991 writeln!(w, "\t\tlet mut rust_obj = {} {{ inner: ObjOps::heap_alloc(obj), is_owned: true }};", ident).unwrap();
992 writeln!(w, "\t\tlet mut ret = {}_as_{}(&rust_obj);", ident, trait_obj.ident).unwrap();
993 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();
994 writeln!(w, "\t\trust_obj.inner = core::ptr::null_mut();").unwrap();
995 writeln!(w, "\t\tret.free = Some({}_free_void);", ident).unwrap();
996 writeln!(w, "\t\tret").unwrap();
998 writeln!(w, "\t}}\n}}").unwrap();
999 if is_type_unconstructable(&resolved_path) {
1000 // We don't bother with Struct_as_Trait conversion for types which must
1001 // never be instantiated, so just return early.
1005 writeln!(w, "/// Constructs a new {} which calls the relevant methods on this_arg.", trait_obj.ident).unwrap();
1006 writeln!(w, "/// This copies the `inner` pointer in this_arg and thus the returned {} must be freed before this_arg is", trait_obj.ident).unwrap();
1007 write!(w, "#[no_mangle]\npub extern \"C\" fn {}_as_{}(this_arg: &{}) -> crate::{} {{\n", ident, trait_obj.ident, ident, full_trait_path).unwrap();
1008 writeln!(w, "\tcrate::{} {{", full_trait_path).unwrap();
1009 writeln!(w, "\t\tthis_arg: unsafe {{ ObjOps::untweak_ptr((*this_arg).inner) as *mut c_void }},").unwrap();
1010 writeln!(w, "\t\tfree: None,").unwrap();
1012 macro_rules! write_meth {
1013 ($m: expr, $trait: expr, $indent: expr) => {
1014 let trait_method = $trait.items.iter().filter_map(|item| {
1015 if let syn::TraitItem::Method(t_m) = item { Some(t_m) } else { None }
1016 }).find(|trait_meth| trait_meth.sig.ident == $m.sig.ident).unwrap();
1017 match export_status(&trait_method.attrs) {
1018 ExportStatus::Export => {},
1019 ExportStatus::NoExport => {
1020 write!(w, "{}\t\t//XXX: Need to export {}\n", $indent, $m.sig.ident).unwrap();
1023 ExportStatus::TestOnly => continue,
1024 ExportStatus::NotImplementable => panic!("(C-not implementable) must only appear on traits"),
1027 let mut printed = false;
1028 if let syn::ReturnType::Type(_, rtype) = &$m.sig.output {
1029 if let syn::Type::Reference(r) = &**rtype {
1030 write!(w, "\n\t\t{}{}: ", $indent, $m.sig.ident).unwrap();
1031 types.write_empty_rust_val(Some(&gen_types), w, &*r.elem);
1032 writeln!(w, ",\n{}\t\tset_{}: Some({}_{}_set_{}),", $indent, $m.sig.ident, ident, $trait.ident, $m.sig.ident).unwrap();
1037 write!(w, "{}\t\t{}: {}_{}_{},\n", $indent, $m.sig.ident, ident, $trait.ident, $m.sig.ident).unwrap();
1041 for item in trait_obj.items.iter() {
1043 syn::TraitItem::Method(m) => {
1044 write_meth!(m, trait_obj, "");
1049 let mut requires_clone = false;
1050 walk_supertraits!(trait_obj, Some(&types), (
1052 requires_clone = true;
1053 writeln!(w, "\t\tcloned: Some({}_{}_cloned),", trait_obj.ident, ident).unwrap();
1055 ("Sync", _) => {}, ("Send", _) => {},
1056 ("std::marker::Sync", _) => {}, ("std::marker::Send", _) => {},
1057 ("core::fmt::Debug", _) => {},
1059 if let Some(supertrait_obj) = types.crate_types.traits.get(s) {
1060 writeln!(w, "\t\t{}: crate::{} {{", t, s).unwrap();
1061 writeln!(w, "\t\t\tthis_arg: unsafe {{ ObjOps::untweak_ptr((*this_arg).inner) as *mut c_void }},").unwrap();
1062 writeln!(w, "\t\t\tfree: None,").unwrap();
1063 for item in supertrait_obj.items.iter() {
1065 syn::TraitItem::Method(m) => {
1066 write_meth!(m, supertrait_obj, "\t");
1071 write!(w, "\t\t}},\n").unwrap();
1073 write_trait_impl_field_assign(w, s, ident);
1077 writeln!(w, "\t}}\n}}\n").unwrap();
1079 macro_rules! impl_meth {
1080 ($m: expr, $trait_meth: expr, $trait_path: expr, $trait: expr, $indent: expr, $types: expr) => {
1081 let trait_method = $trait.items.iter().filter_map(|item| {
1082 if let syn::TraitItem::Method(t_m) = item { Some(t_m) } else { None }
1083 }).find(|trait_meth| trait_meth.sig.ident == $m.sig.ident).unwrap();
1084 match export_status(&trait_method.attrs) {
1085 ExportStatus::Export => {},
1086 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1087 ExportStatus::NotImplementable => panic!("(C-not implementable) must only appear on traits"),
1090 if let syn::ReturnType::Type(_, _) = &$m.sig.output {
1091 writeln!(w, "#[must_use]").unwrap();
1093 write!(w, "extern \"C\" fn {}_{}_{}(", ident, $trait.ident, $m.sig.ident).unwrap();
1094 let mut meth_gen_types = gen_types.push_ctx();
1095 assert!(meth_gen_types.learn_generics(&$m.sig.generics, $types));
1096 let mut uncallable_function = false;
1097 for inp in $m.sig.inputs.iter() {
1099 syn::FnArg::Typed(arg) => {
1100 if $types.skip_arg(&*arg.ty, Some(&meth_gen_types)) { continue; }
1101 let mut c_type = Vec::new();
1102 $types.write_c_type(&mut c_type, &*arg.ty, Some(&meth_gen_types), false);
1103 if is_type_unconstructable(&String::from_utf8(c_type).unwrap()) {
1104 uncallable_function = true;
1110 write_method_params(w, &$trait_meth.sig, "c_void", &mut trait_resolver, Some(&meth_gen_types), true, true);
1111 write!(w, " {{\n\t").unwrap();
1112 if uncallable_function {
1113 write!(w, "unreachable!();").unwrap();
1115 write_method_var_decl_body(w, &$trait_meth.sig, "", &mut trait_resolver, Some(&meth_gen_types), false);
1116 let mut takes_self = false;
1117 for inp in $m.sig.inputs.iter() {
1118 if let syn::FnArg::Receiver(_) = inp {
1123 let mut t_gen_args = String::new();
1124 for (idx, _) in $trait.generics.params.iter().enumerate() {
1125 if idx != 0 { t_gen_args += ", " };
1128 // rustc doesn't like <_> if the _ is actually a lifetime, so
1129 // if all the parameters are lifetimes just skip it.
1130 let mut nonlifetime_param = false;
1131 for param in $trait.generics.params.iter() {
1132 if let syn::GenericParam::Lifetime(_) = param {}
1133 else { nonlifetime_param = true; }
1135 if !nonlifetime_param { t_gen_args = String::new(); }
1137 write!(w, "<native{} as {}<{}>>::{}(unsafe {{ &mut *(this_arg as *mut native{}) }}, ", ident, $trait_path, t_gen_args, $m.sig.ident, ident).unwrap();
1139 write!(w, "<native{} as {}<{}>>::{}(", ident, $trait_path, t_gen_args, $m.sig.ident).unwrap();
1142 let mut real_type = "".to_string();
1143 match &$m.sig.output {
1144 syn::ReturnType::Type(_, rtype) => {
1145 if let Some(mut remaining_path) = first_seg_self(&*rtype) {
1146 if let Some(associated_seg) = get_single_remaining_path_seg(&mut remaining_path) {
1147 real_type = format!("{}", impl_associated_types.get(associated_seg).unwrap());
1153 write_method_call_params(w, &$trait_meth.sig, "", &mut trait_resolver, Some(&meth_gen_types), &real_type, false);
1155 write!(w, "\n}}\n").unwrap();
1156 if let syn::ReturnType::Type(_, rtype) = &$m.sig.output {
1157 if let syn::Type::Reference(r) = &**rtype {
1158 assert_eq!($m.sig.inputs.len(), 1); // Must only take self
1159 writeln!(w, "extern \"C\" fn {}_{}_set_{}(trait_self_arg: &{}) {{", ident, $trait.ident, $m.sig.ident, $trait.ident).unwrap();
1160 writeln!(w, "\t// This is a bit race-y in the general case, but for our specific use-cases today, we're safe").unwrap();
1161 writeln!(w, "\t// Specifically, we must ensure that the first time we're called it can never be in parallel").unwrap();
1162 write!(w, "\tif ").unwrap();
1163 $types.write_empty_rust_val_check(Some(&meth_gen_types), w, &*r.elem, &format!("trait_self_arg.{}", $m.sig.ident));
1164 writeln!(w, " {{").unwrap();
1165 writeln!(w, "\t\tunsafe {{ &mut *(trait_self_arg as *const {} as *mut {}) }}.{} = {}_{}_{}(trait_self_arg.this_arg);", $trait.ident, $trait.ident, $m.sig.ident, ident, $trait.ident, $m.sig.ident).unwrap();
1166 writeln!(w, "\t}}").unwrap();
1167 writeln!(w, "}}").unwrap();
1173 'impl_item_loop: for trait_item in trait_obj.items.iter() {
1175 syn::TraitItem::Method(meth) => {
1176 for item in i.items.iter() {
1178 syn::ImplItem::Method(m) => {
1179 if meth.sig.ident == m.sig.ident {
1180 impl_meth!(m, meth, full_trait_path, trait_obj, "", types);
1181 continue 'impl_item_loop;
1184 syn::ImplItem::Type(_) => {},
1185 _ => unimplemented!(),
1188 assert!(meth.default.is_some());
1189 let old_gen_types = gen_types;
1190 gen_types = GenericTypes::new(Some(resolved_path.clone()));
1191 impl_meth!(meth, meth, full_trait_path, trait_obj, "", &mut trait_resolver);
1192 gen_types = old_gen_types;
1198 writeln!(w, "extern \"C\" fn {}_{}_cloned(new_obj: &mut crate::{}) {{", trait_obj.ident, ident, full_trait_path).unwrap();
1199 writeln!(w, "\tnew_obj.this_arg = {}_clone_void(new_obj.this_arg);", ident).unwrap();
1200 writeln!(w, "\tnew_obj.free = Some({}_free_void);", ident).unwrap();
1201 walk_supertraits!(trait_obj, Some(&types), (
1203 if types.crate_types.traits.get(s).is_some() {
1204 assert!(!types.is_clonable(s)); // We don't currently support cloning with a clonable supertrait
1205 writeln!(w, "\tnew_obj.{}.this_arg = new_obj.this_arg;", t).unwrap();
1206 writeln!(w, "\tnew_obj.{}.free = None;", t).unwrap();
1210 writeln!(w, "}}").unwrap();
1212 write!(w, "\n").unwrap();
1215 if is_type_unconstructable(&resolved_path) {
1216 // Don't bother exposing trait implementations for objects which cannot be
1220 if path_matches_nongeneric(&trait_path.1, &["From"]) {
1221 } else if path_matches_nongeneric(&trait_path.1, &["Default"]) {
1222 writeln!(w, "/// Creates a \"default\" {}. See struct and individual field documentaiton for details on which values are used.", ident).unwrap();
1223 write!(w, "#[must_use]\n#[no_mangle]\npub extern \"C\" fn {}_default() -> {} {{\n", ident, ident).unwrap();
1224 write!(w, "\t{} {{ inner: ObjOps::heap_alloc(Default::default()), is_owned: true }}\n", ident).unwrap();
1225 write!(w, "}}\n").unwrap();
1226 } else if path_matches_nongeneric(&trait_path.1, &["core", "cmp", "PartialEq"]) {
1227 } else if path_matches_nongeneric(&trait_path.1, &["core", "cmp", "Eq"]) {
1228 writeln!(w, "/// Checks if two {}s contain equal inner contents.", ident).unwrap();
1229 writeln!(w, "/// This ignores pointers and is_owned flags and looks at the values in fields.").unwrap();
1230 if types.c_type_has_inner_from_path(&resolved_path) {
1231 writeln!(w, "/// Two objects with NULL inner values will be considered \"equal\" here.").unwrap();
1233 write!(w, "#[no_mangle]\npub extern \"C\" fn {}_eq(a: &{}, b: &{}) -> bool {{\n", ident, ident, ident).unwrap();
1234 if types.c_type_has_inner_from_path(&resolved_path) {
1235 write!(w, "\tif a.inner == b.inner {{ return true; }}\n").unwrap();
1236 write!(w, "\tif a.inner.is_null() || b.inner.is_null() {{ return false; }}\n").unwrap();
1240 let ref_type: syn::Type = syn::parse_quote!(&#path);
1241 assert!(!types.write_to_c_conversion_new_var(w, &format_ident!("a"), &*i.self_ty, Some(&gen_types), false), "We don't support new var conversions when comparing equality");
1243 write!(w, "\tif ").unwrap();
1244 types.write_from_c_conversion_prefix(w, &ref_type, Some(&gen_types));
1245 write!(w, "a").unwrap();
1246 types.write_from_c_conversion_suffix(w, &ref_type, Some(&gen_types));
1247 write!(w, " == ").unwrap();
1248 types.write_from_c_conversion_prefix(w, &ref_type, Some(&gen_types));
1249 write!(w, "b").unwrap();
1250 types.write_from_c_conversion_suffix(w, &ref_type, Some(&gen_types));
1252 writeln!(w, " {{ true }} else {{ false }}\n}}").unwrap();
1253 } else if path_matches_nongeneric(&trait_path.1, &["core", "hash", "Hash"]) {
1254 writeln!(w, "/// Checks if two {}s contain equal inner contents.", ident).unwrap();
1255 write!(w, "#[no_mangle]\npub extern \"C\" fn {}_hash(o: &{}) -> u64 {{\n", ident, ident).unwrap();
1256 if types.c_type_has_inner_from_path(&resolved_path) {
1257 write!(w, "\tif o.inner.is_null() {{ return 0; }}\n").unwrap();
1261 let ref_type: syn::Type = syn::parse_quote!(&#path);
1262 assert!(!types.write_to_c_conversion_new_var(w, &format_ident!("a"), &*i.self_ty, Some(&gen_types), false), "We don't support new var conversions when comparing equality");
1264 writeln!(w, "\t// Note that we'd love to use alloc::collections::hash_map::DefaultHasher but it's not in core").unwrap();
1265 writeln!(w, "\t#[allow(deprecated)]").unwrap();
1266 writeln!(w, "\tlet mut hasher = core::hash::SipHasher::new();").unwrap();
1267 write!(w, "\tcore::hash::Hash::hash(").unwrap();
1268 types.write_from_c_conversion_prefix(w, &ref_type, Some(&gen_types));
1269 write!(w, "o").unwrap();
1270 types.write_from_c_conversion_suffix(w, &ref_type, Some(&gen_types));
1271 writeln!(w, ", &mut hasher);").unwrap();
1272 writeln!(w, "\tcore::hash::Hasher::finish(&hasher)\n}}").unwrap();
1273 } else if (path_matches_nongeneric(&trait_path.1, &["core", "clone", "Clone"]) || path_matches_nongeneric(&trait_path.1, &["Clone"])) &&
1274 types.c_type_has_inner_from_path(&resolved_path) {
1275 writeln!(w, "impl Clone for {} {{", ident).unwrap();
1276 writeln!(w, "\tfn clone(&self) -> Self {{").unwrap();
1277 writeln!(w, "\t\tSelf {{").unwrap();
1278 writeln!(w, "\t\t\tinner: if <*mut native{}>::is_null(self.inner) {{ core::ptr::null_mut() }} else {{", ident).unwrap();
1279 writeln!(w, "\t\t\t\tObjOps::heap_alloc(unsafe {{ &*ObjOps::untweak_ptr(self.inner) }}.clone()) }},").unwrap();
1280 writeln!(w, "\t\t\tis_owned: true,").unwrap();
1281 writeln!(w, "\t\t}}\n\t}}\n}}").unwrap();
1282 writeln!(w, "#[allow(unused)]").unwrap();
1283 writeln!(w, "/// Used only if an object of this type is returned as a trait impl by a method").unwrap();
1284 writeln!(w, "pub(crate) extern \"C\" fn {}_clone_void(this_ptr: *const c_void) -> *mut c_void {{", ident).unwrap();
1285 writeln!(w, "\tBox::into_raw(Box::new(unsafe {{ (*(this_ptr as *mut native{})).clone() }})) as *mut c_void", ident).unwrap();
1286 writeln!(w, "}}").unwrap();
1287 writeln!(w, "#[no_mangle]").unwrap();
1288 writeln!(w, "/// Creates a copy of the {}", ident).unwrap();
1289 writeln!(w, "pub extern \"C\" fn {}_clone(orig: &{}) -> {} {{", ident, ident, ident).unwrap();
1290 writeln!(w, "\torig.clone()").unwrap();
1291 writeln!(w, "}}").unwrap();
1292 } else if path_matches_nongeneric(&trait_path.1, &["FromStr"]) {
1293 let mut err_opt = None;
1294 for item in i.items.iter() {
1296 syn::ImplItem::Type(ty) if format!("{}", ty.ident) == "Err" => {
1297 err_opt = Some(&ty.ty);
1302 let err_ty = err_opt.unwrap();
1303 if let Some(container) = types.get_c_mangled_container_type(vec![&*i.self_ty, &err_ty], Some(&gen_types), "Result") {
1304 writeln!(w, "#[no_mangle]").unwrap();
1305 writeln!(w, "/// Read a {} object from a string", ident).unwrap();
1306 writeln!(w, "pub extern \"C\" fn {}_from_str(s: crate::c_types::Str) -> {} {{", ident, container).unwrap();
1307 writeln!(w, "\tmatch {}::from_str(s.into_str()) {{", resolved_path).unwrap();
1309 writeln!(w, "\t\tOk(r) => {{").unwrap();
1310 let new_var = types.write_to_c_conversion_new_var(w, &format_ident!("r"), &*i.self_ty, Some(&gen_types), false);
1311 write!(w, "\t\t\tcrate::c_types::CResultTempl::ok(\n\t\t\t\t").unwrap();
1312 types.write_to_c_conversion_inline_prefix(w, &*i.self_ty, Some(&gen_types), false);
1313 write!(w, "{}r", if new_var { "local_" } else { "" }).unwrap();
1314 types.write_to_c_conversion_inline_suffix(w, &*i.self_ty, Some(&gen_types), false);
1315 writeln!(w, "\n\t\t\t)\n\t\t}},").unwrap();
1317 writeln!(w, "\t\tErr(e) => {{").unwrap();
1318 let new_var = types.write_to_c_conversion_new_var(w, &format_ident!("e"), &err_ty, Some(&gen_types), false);
1319 write!(w, "\t\t\tcrate::c_types::CResultTempl::err(\n\t\t\t\t").unwrap();
1320 types.write_to_c_conversion_inline_prefix(w, &err_ty, Some(&gen_types), false);
1321 write!(w, "{}e", if new_var { "local_" } else { "" }).unwrap();
1322 types.write_to_c_conversion_inline_suffix(w, &err_ty, Some(&gen_types), false);
1323 writeln!(w, "\n\t\t\t)\n\t\t}},").unwrap();
1325 writeln!(w, "\t}}.into()\n}}").unwrap();
1327 } else if path_matches_nongeneric(&trait_path.1, &["Display"]) {
1328 writeln!(w, "#[no_mangle]").unwrap();
1329 writeln!(w, "/// Get the string representation of a {} object", ident).unwrap();
1330 writeln!(w, "pub extern \"C\" fn {}_to_str(o: &crate::{}) -> Str {{", ident, resolved_path).unwrap();
1332 let self_ty = &i.self_ty;
1333 let ref_type: syn::Type = syn::parse_quote!(&#self_ty);
1334 let new_var = types.write_from_c_conversion_new_var(w, &format_ident!("o"), &ref_type, Some(&gen_types));
1335 write!(w, "\talloc::format!(\"{{}}\", ").unwrap();
1336 types.write_from_c_conversion_prefix(w, &ref_type, Some(&gen_types));
1337 write!(w, "{}o", if new_var { "local_" } else { "" }).unwrap();
1338 types.write_from_c_conversion_suffix(w, &ref_type, Some(&gen_types));
1339 writeln!(w, ").into()").unwrap();
1341 writeln!(w, "}}").unwrap();
1343 //XXX: implement for other things like ToString
1344 // If we have no generics, try a manual implementation:
1345 maybe_convert_trait_impl(w, &trait_path.1, &*i.self_ty, types, &gen_types);
1348 let is_opaque = types.crate_types.opaques.contains_key(&resolved_path);
1349 let is_mirrored_enum = types.crate_types.mirrored_enums.contains_key(&resolved_path);
1350 for item in i.items.iter() {
1352 syn::ImplItem::Method(m) => {
1353 if let syn::Visibility::Public(_) = m.vis {
1354 match export_status(&m.attrs) {
1355 ExportStatus::Export => {},
1356 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1357 ExportStatus::NotImplementable => panic!("(C-not implementable) must only appear on traits"),
1359 let mut meth_gen_types = gen_types.push_ctx();
1360 assert!(meth_gen_types.learn_generics(&m.sig.generics, types));
1361 if m.defaultness.is_some() { unimplemented!(); }
1362 writeln_fn_docs(w, &m.attrs, "", types, Some(&meth_gen_types), m.sig.inputs.iter(), &m.sig.output);
1363 if let syn::ReturnType::Type(_, _) = &m.sig.output {
1364 writeln!(w, "#[must_use]").unwrap();
1366 write!(w, "#[no_mangle]\npub extern \"C\" fn {}_{}(", ident, m.sig.ident).unwrap();
1367 let ret_type = format!("crate::{}", resolved_path);
1368 write_method_params(w, &m.sig, &ret_type, types, Some(&meth_gen_types), false, true);
1369 write!(w, " {{\n\t").unwrap();
1370 write_method_var_decl_body(w, &m.sig, "", types, Some(&meth_gen_types), false);
1371 let mut takes_self = false;
1372 let mut takes_mut_self = false;
1373 let mut takes_owned_self = false;
1374 for inp in m.sig.inputs.iter() {
1375 if let syn::FnArg::Receiver(r) = inp {
1377 if r.mutability.is_some() { takes_mut_self = true; }
1378 if r.reference.is_none() { takes_owned_self = true; }
1381 if !takes_mut_self && !takes_self {
1382 write!(w, "{}::{}(", resolved_path, m.sig.ident).unwrap();
1384 if is_mirrored_enum {
1385 write!(w, "this_arg.to_native().{}(", m.sig.ident).unwrap();
1386 } else if is_opaque {
1387 if takes_owned_self {
1388 write!(w, "(*unsafe {{ Box::from_raw(this_arg.take_inner()) }}).{}(", m.sig.ident).unwrap();
1389 } else if takes_mut_self {
1390 write!(w, "unsafe {{ &mut (*ObjOps::untweak_ptr(this_arg.inner as *mut crate::{}::native{})) }}.{}(", rsplit_once(&resolved_path, "::").unwrap().0, ident, m.sig.ident).unwrap();
1392 write!(w, "unsafe {{ &*ObjOps::untweak_ptr(this_arg.inner) }}.{}(", m.sig.ident).unwrap();
1398 write_method_call_params(w, &m.sig, "", types, Some(&meth_gen_types), &ret_type, false);
1399 writeln!(w, "\n}}\n").unwrap();
1406 } else if let Some(resolved_path) = types.maybe_resolve_ident(&ident) {
1407 create_alias_for_impl(resolved_path, i, types, move |aliased_impl, types| writeln_impl(w, &aliased_impl, types));
1409 eprintln!("Not implementing anything for {} due to no-resolve (probably the type isn't pub)", ident);
1415 fn create_alias_for_impl<F: FnMut(syn::ItemImpl, &mut TypeResolver)>(resolved_path: String, i: &syn::ItemImpl, types: &mut TypeResolver, mut callback: F) {
1416 if let Some(aliases) = types.crate_types.reverse_alias_map.get(&resolved_path).cloned() {
1417 let mut gen_types = Some(GenericTypes::new(Some(resolved_path.clone())));
1418 if !gen_types.as_mut().unwrap().learn_generics(&i.generics, types) {
1421 let alias_module = rsplit_once(&resolved_path, "::").unwrap().0;
1423 'alias_impls: for (alias_resolved, arguments) in aliases {
1424 let mut new_ty_generics = Vec::new();
1425 let mut new_ty_bounds = Vec::new();
1426 let mut need_generics = false;
1428 let alias_resolver_override;
1429 let alias_resolver = if alias_module != types.module_path {
1430 alias_resolver_override = ImportResolver::new(types.types.crate_name, &types.crate_types.lib_ast.dependencies,
1431 alias_module, &types.crate_types.lib_ast.modules.get(alias_module).unwrap().items);
1432 &alias_resolver_override
1433 } else { &types.types };
1434 let mut where_clause = syn::WhereClause { where_token: syn::Token![where](Span::call_site()),
1435 predicates: syn::punctuated::Punctuated::new()
1437 for (idx, gen) in i.generics.params.iter().enumerate() {
1439 syn::GenericParam::Type(type_param) => {
1440 'bounds_check: for bound in type_param.bounds.iter() {
1441 if let syn::TypeParamBound::Trait(trait_bound) = bound {
1442 if let syn::PathArguments::AngleBracketed(ref t) = &arguments {
1443 assert!(idx < t.args.len());
1444 if let syn::GenericArgument::Type(syn::Type::Path(p)) = &t.args[idx] {
1445 let generic_bound = types.maybe_resolve_path(&trait_bound.path, None)
1446 .unwrap_or_else(|| format!("{}::{}", types.module_path, single_ident_generic_path_to_ident(&trait_bound.path).unwrap()));
1448 if let Some(generic_arg) = alias_resolver.maybe_resolve_path(&p.path, None) {
1449 new_ty_generics.push((type_param.ident.clone(), syn::Type::Path(p.clone())));
1450 if let Some(traits_impld) = types.crate_types.trait_impls.get(&generic_arg) {
1451 for trait_impld in traits_impld {
1452 if *trait_impld == generic_bound { continue 'bounds_check; }
1454 eprintln!("struct {}'s generic arg {} didn't match bound {}", alias_resolved, generic_arg, generic_bound);
1455 continue 'alias_impls;
1457 eprintln!("struct {}'s generic arg {} didn't match bound {}", alias_resolved, generic_arg, generic_bound);
1458 continue 'alias_impls;
1460 } else if gen_types.is_some() {
1461 let resp = types.maybe_resolve_path(&p.path, gen_types.as_ref());
1462 if generic_bound == "core::ops::Deref" && resp.is_some() {
1463 new_ty_bounds.push((type_param.ident.clone(),
1464 string_path_to_syn_path("core::ops::Deref")));
1465 let mut bounds = syn::punctuated::Punctuated::new();
1466 bounds.push(syn::TypeParamBound::Trait(syn::TraitBound {
1468 modifier: syn::TraitBoundModifier::None,
1470 path: string_path_to_syn_path(&types.resolve_path(&p.path, gen_types.as_ref())),
1472 let mut path = string_path_to_syn_path(&format!("{}::Target", type_param.ident));
1473 path.leading_colon = None;
1474 where_clause.predicates.push(syn::WherePredicate::Type(syn::PredicateType {
1476 bounded_ty: syn::Type::Path(syn::TypePath { qself: None, path }),
1477 colon_token: syn::Token![:](Span::call_site()),
1481 new_ty_generics.push((type_param.ident.clone(),
1482 gen_types.as_ref().resolve_type(&syn::Type::Path(p.clone())).clone()));
1484 need_generics = true;
1488 } else { unimplemented!(); }
1489 } else { unimplemented!(); }
1490 } else { unimplemented!(); }
1493 syn::GenericParam::Lifetime(_) => {},
1494 syn::GenericParam::Const(_) => unimplemented!(),
1497 let mut params = syn::punctuated::Punctuated::new();
1498 let alias = string_path_to_syn_path(&alias_resolved);
1501 let alias_generics = types.crate_types.opaques.get(&alias_resolved).unwrap().1;
1503 // If we need generics on the alias, create impl generic bounds...
1504 assert_eq!(new_ty_generics.len() + new_ty_bounds.len(), i.generics.params.len());
1505 let mut args = syn::punctuated::Punctuated::new();
1506 for (ident, param) in new_ty_generics.drain(..) {
1507 // TODO: We blindly assume that generics in the type alias and
1508 // the aliased type have the same names, which we really shouldn't.
1509 if alias_generics.params.iter().any(|generic|
1510 if let syn::GenericParam::Type(t) = generic { t.ident == ident } else { false })
1512 args.push(parse_quote!(#ident));
1514 params.push(syn::GenericParam::Type(syn::TypeParam {
1518 bounds: syn::punctuated::Punctuated::new(),
1519 eq_token: Some(syn::token::Eq(Span::call_site())),
1520 default: Some(param),
1523 for (ident, param) in new_ty_bounds.drain(..) {
1524 // TODO: We blindly assume that generics in the type alias and
1525 // the aliased type have the same names, which we really shouldn't.
1526 if alias_generics.params.iter().any(|generic|
1527 if let syn::GenericParam::Type(t) = generic { t.ident == ident } else { false })
1529 args.push(parse_quote!(#ident));
1531 params.push(syn::GenericParam::Type(syn::TypeParam {
1534 colon_token: Some(syn::token::Colon(Span::call_site())),
1535 bounds: syn::punctuated::Punctuated::from_iter(
1536 Some(syn::TypeParamBound::Trait(syn::TraitBound {
1537 path: param, paren_token: None, lifetimes: None,
1538 modifier: syn::TraitBoundModifier::None,
1545 // ... and swap the last segment of the impl self_ty to use the generic bounds.
1546 let mut res = alias.clone();
1547 res.segments.last_mut().unwrap().arguments = syn::PathArguments::AngleBracketed(syn::AngleBracketedGenericArguments {
1549 lt_token: syn::token::Lt(Span::call_site()),
1551 gt_token: syn::token::Gt(Span::call_site()),
1554 } else { alias.clone() };
1555 callback(syn::ItemImpl {
1556 attrs: i.attrs.clone(),
1557 brace_token: syn::token::Brace(Span::call_site()),
1559 generics: syn::Generics {
1563 where_clause: Some(where_clause),
1565 impl_token: syn::Token![impl](Span::call_site()),
1566 items: i.items.clone(),
1567 self_ty: Box::new(syn::Type::Path(syn::TypePath { qself: None, path: real_aliased })),
1568 trait_: i.trait_.clone(),
1573 eprintln!("Not implementing anything for {} due to it being marked not exported", resolved_path);
1577 /// Replaces upper case charachters with underscore followed by lower case except the first
1578 /// charachter and repeated upper case characthers (which are only made lower case).
1579 fn camel_to_snake_case(camel: &str) -> String {
1580 let mut res = "".to_string();
1581 let mut last_upper = -1;
1582 for (idx, c) in camel.chars().enumerate() {
1583 if c.is_uppercase() {
1584 if last_upper != idx as isize - 1 { res.push('_'); }
1585 res.push(c.to_lowercase().next().unwrap());
1586 last_upper = idx as isize;
1595 /// Print a mapping of an enum. If all of the enum's fields are C-mapped in some form (or the enum
1596 /// is unitary), we generate an equivalent enum with all types replaced with their C mapped
1597 /// versions followed by conversion functions which map between the Rust version and the C mapped
1599 fn writeln_enum<'a, 'b, W: std::io::Write>(w: &mut W, e: &'a syn::ItemEnum, types: &mut TypeResolver<'b, 'a>, extra_headers: &mut File, cpp_headers: &mut File) {
1600 match export_status(&e.attrs) {
1601 ExportStatus::Export => {},
1602 ExportStatus::NoExport|ExportStatus::TestOnly => return,
1603 ExportStatus::NotImplementable => panic!("(C-not implementable) must only appear on traits"),
1606 if is_enum_opaque(e) {
1607 eprintln!("Skipping enum {} as it contains non-unit fields", e.ident);
1608 writeln_opaque(w, &e.ident, &format!("{}", e.ident), &e.generics, &e.attrs, types, extra_headers, cpp_headers);
1611 writeln_docs(w, &e.attrs, "");
1613 let mut gen_types = GenericTypes::new(None);
1614 assert!(gen_types.learn_generics(&e.generics, types));
1616 let mut needs_free = false;
1617 let mut constr = Vec::new();
1618 let mut is_clonable = true;
1620 for var in e.variants.iter() {
1621 if let syn::Fields::Named(fields) = &var.fields {
1623 for field in fields.named.iter() {
1624 if export_status(&field.attrs) == ExportStatus::TestOnly { continue; }
1626 let mut ty_checks = Vec::new();
1627 types.write_c_type(&mut ty_checks, &field.ty, Some(&gen_types), false);
1628 if !types.is_clonable(&String::from_utf8(ty_checks).unwrap()) {
1629 is_clonable = false;
1632 } else if let syn::Fields::Unnamed(fields) = &var.fields {
1633 for field in fields.unnamed.iter() {
1634 let mut ty_checks = Vec::new();
1635 types.write_c_type(&mut ty_checks, &field.ty, Some(&gen_types), false);
1636 let ty = String::from_utf8(ty_checks).unwrap();
1637 if ty != "" && !types.is_clonable(&ty) {
1638 is_clonable = false;
1645 writeln!(w, "#[derive(Clone)]").unwrap();
1646 types.crate_types.set_clonable(format!("{}::{}", types.module_path, e.ident));
1648 writeln!(w, "#[must_use]\n#[repr(C)]\npub enum {} {{", e.ident).unwrap();
1649 for var in e.variants.iter() {
1650 assert_eq!(export_status(&var.attrs), ExportStatus::Export); // We can't partially-export a mirrored enum
1651 writeln_docs(w, &var.attrs, "\t");
1652 write!(w, "\t{}", var.ident).unwrap();
1653 writeln!(&mut constr, "#[no_mangle]\n/// Utility method to constructs a new {}-variant {}", var.ident, e.ident).unwrap();
1654 let constr_name = camel_to_snake_case(&format!("{}", var.ident));
1655 write!(&mut constr, "pub extern \"C\" fn {}_{}(", e.ident, constr_name).unwrap();
1656 let mut empty_tuple_variant = false;
1657 if let syn::Fields::Named(fields) = &var.fields {
1659 writeln!(w, " {{").unwrap();
1660 for (idx, field) in fields.named.iter().enumerate() {
1661 if export_status(&field.attrs) == ExportStatus::TestOnly { continue; }
1662 writeln_field_docs(w, &field.attrs, "\t\t", types, Some(&gen_types), &field.ty);
1663 write!(w, "\t\t{}: ", field.ident.as_ref().unwrap()).unwrap();
1664 write!(&mut constr, "{}{}: ", if idx != 0 { ", " } else { "" }, field.ident.as_ref().unwrap()).unwrap();
1665 types.write_c_type(w, &field.ty, Some(&gen_types), true);
1666 types.write_c_type(&mut constr, &field.ty, Some(&gen_types), true);
1667 writeln!(w, ",").unwrap();
1669 write!(w, "\t}}").unwrap();
1670 } else if let syn::Fields::Unnamed(fields) = &var.fields {
1671 if fields.unnamed.len() == 1 {
1672 let mut empty_check = Vec::new();
1673 types.write_c_type(&mut empty_check, &fields.unnamed[0].ty, Some(&gen_types), true);
1674 if empty_check.is_empty() {
1675 empty_tuple_variant = true;
1678 if !empty_tuple_variant {
1680 writeln!(w, "(").unwrap();
1681 for (idx, field) in fields.unnamed.iter().enumerate() {
1682 if export_status(&field.attrs) == ExportStatus::TestOnly { continue; }
1683 writeln_field_docs(w, &field.attrs, "\t\t", types, Some(&gen_types), &field.ty);
1684 write!(w, "\t\t").unwrap();
1685 types.write_c_type(w, &field.ty, Some(&gen_types), true);
1687 write!(&mut constr, "{}: ", ('a' as u8 + idx as u8) as char).unwrap();
1688 types.write_c_type(&mut constr, &field.ty, Some(&gen_types), false);
1689 if idx != fields.unnamed.len() - 1 {
1690 writeln!(w, ",").unwrap();
1691 write!(&mut constr, ",").unwrap();
1694 write!(w, ")").unwrap();
1697 if var.discriminant.is_some() { unimplemented!(); }
1698 write!(&mut constr, ") -> {} {{\n\t{}::{}", e.ident, e.ident, var.ident).unwrap();
1699 if let syn::Fields::Named(fields) = &var.fields {
1700 writeln!(&mut constr, " {{").unwrap();
1701 for field in fields.named.iter() {
1702 writeln!(&mut constr, "\t\t{},", field.ident.as_ref().unwrap()).unwrap();
1704 writeln!(&mut constr, "\t}}").unwrap();
1705 } else if let syn::Fields::Unnamed(fields) = &var.fields {
1706 if !empty_tuple_variant {
1707 write!(&mut constr, "(").unwrap();
1708 for (idx, field) in fields.unnamed.iter().enumerate() {
1709 let mut ref_c_ty = Vec::new();
1710 let mut nonref_c_ty = Vec::new();
1711 types.write_c_type(&mut ref_c_ty, &field.ty, Some(&gen_types), false);
1712 types.write_c_type(&mut nonref_c_ty, &field.ty, Some(&gen_types), true);
1714 if ref_c_ty != nonref_c_ty {
1715 // We blindly assume references in field types are always opaque types, and
1716 // print out an opaque reference -> owned reference conversion here.
1717 write!(&mut constr, "{} {{ inner: {}.inner, is_owned: false }}, ", String::from_utf8(nonref_c_ty).unwrap(), ('a' as u8 + idx as u8) as char).unwrap();
1719 write!(&mut constr, "{}, ", ('a' as u8 + idx as u8) as char).unwrap();
1722 writeln!(&mut constr, ")").unwrap();
1724 writeln!(&mut constr, "").unwrap();
1727 writeln!(&mut constr, "}}").unwrap();
1728 writeln!(w, ",").unwrap();
1730 writeln!(w, "}}\nuse {}::{} as {}Import;", types.module_path, e.ident, e.ident).unwrap();
1731 write!(w, "pub(crate) type native{} = {}Import", e.ident, e.ident).unwrap();
1732 maybe_write_generics(w, &e.generics, &types, true);
1733 writeln!(w, ";\n\nimpl {} {{", e.ident).unwrap();
1735 macro_rules! write_conv {
1736 ($fn_sig: expr, $to_c: expr, $ref: expr) => {
1737 writeln!(w, "\t#[allow(unused)]\n\tpub(crate) fn {} {{\n\t\tmatch {} {{", $fn_sig, if $to_c { "native" } else { "self" }).unwrap();
1738 for var in e.variants.iter() {
1739 write!(w, "\t\t\t{}{}::{} ", if $to_c { "native" } else { "" }, e.ident, var.ident).unwrap();
1740 let mut empty_tuple_variant = false;
1741 if let syn::Fields::Named(fields) = &var.fields {
1742 write!(w, "{{").unwrap();
1743 for field in fields.named.iter() {
1744 if export_status(&field.attrs) == ExportStatus::TestOnly { continue; }
1745 write!(w, "{}{}, ", if $ref { "ref " } else { "mut " }, field.ident.as_ref().unwrap()).unwrap();
1747 write!(w, "}} ").unwrap();
1748 } else if let syn::Fields::Unnamed(fields) = &var.fields {
1749 if fields.unnamed.len() == 1 {
1750 let mut empty_check = Vec::new();
1751 types.write_c_type(&mut empty_check, &fields.unnamed[0].ty, Some(&gen_types), true);
1752 if empty_check.is_empty() {
1753 empty_tuple_variant = true;
1756 if !empty_tuple_variant || $to_c {
1757 write!(w, "(").unwrap();
1758 for (idx, field) in fields.unnamed.iter().enumerate() {
1759 if export_status(&field.attrs) == ExportStatus::TestOnly { continue; }
1760 write!(w, "{}{}, ", if $ref { "ref " } else { "mut " }, ('a' as u8 + idx as u8) as char).unwrap();
1762 write!(w, ") ").unwrap();
1765 write!(w, "=>").unwrap();
1767 macro_rules! handle_field_a {
1768 ($field: expr, $field_ident: expr) => { {
1769 if export_status(&$field.attrs) == ExportStatus::TestOnly { continue; }
1770 let mut sink = ::std::io::sink();
1771 let mut out: &mut dyn std::io::Write = if $ref { &mut sink } else { w };
1772 let new_var = if $to_c {
1773 types.write_to_c_conversion_new_var(&mut out, $field_ident, &$field.ty, Some(&gen_types), true)
1775 types.write_from_c_conversion_new_var(&mut out, $field_ident, &$field.ty, Some(&gen_types))
1777 if $ref || new_var {
1779 write!(w, "let mut {}_nonref = (*{}).clone();\n\t\t\t\t", $field_ident, $field_ident).unwrap();
1781 let nonref_ident = format_ident!("{}_nonref", $field_ident);
1783 types.write_to_c_conversion_new_var(w, &nonref_ident, &$field.ty, Some(&gen_types), true);
1785 types.write_from_c_conversion_new_var(w, &nonref_ident, &$field.ty, Some(&gen_types));
1787 write!(w, "\n\t\t\t\t").unwrap();
1790 write!(w, "\n\t\t\t\t").unwrap();
1795 if let syn::Fields::Named(fields) = &var.fields {
1796 write!(w, " {{\n\t\t\t\t").unwrap();
1797 for field in fields.named.iter() {
1798 handle_field_a!(field, field.ident.as_ref().unwrap());
1800 } else if let syn::Fields::Unnamed(fields) = &var.fields {
1801 write!(w, " {{\n\t\t\t\t").unwrap();
1802 for (idx, field) in fields.unnamed.iter().enumerate() {
1803 if !empty_tuple_variant {
1804 handle_field_a!(field, &format_ident!("{}", ('a' as u8 + idx as u8) as char));
1807 } else { write!(w, " ").unwrap(); }
1809 write!(w, "{}{}::{}", if $to_c { "" } else { "native" }, e.ident, var.ident).unwrap();
1811 macro_rules! handle_field_b {
1812 ($field: expr, $field_ident: expr) => { {
1813 if export_status(&$field.attrs) == ExportStatus::TestOnly { continue; }
1815 types.write_to_c_conversion_inline_prefix(w, &$field.ty, Some(&gen_types), true);
1817 types.write_from_c_conversion_prefix(w, &$field.ty, Some(&gen_types));
1819 write!(w, "{}{}", $field_ident,
1820 if $ref { "_nonref" } else { "" }).unwrap();
1822 types.write_to_c_conversion_inline_suffix(w, &$field.ty, Some(&gen_types), true);
1824 types.write_from_c_conversion_suffix(w, &$field.ty, Some(&gen_types));
1826 write!(w, ",").unwrap();
1830 if let syn::Fields::Named(fields) = &var.fields {
1831 write!(w, " {{").unwrap();
1832 for field in fields.named.iter() {
1833 if export_status(&field.attrs) == ExportStatus::TestOnly { continue; }
1834 write!(w, "\n\t\t\t\t\t{}: ", field.ident.as_ref().unwrap()).unwrap();
1835 handle_field_b!(field, field.ident.as_ref().unwrap());
1837 writeln!(w, "\n\t\t\t\t}}").unwrap();
1838 write!(w, "\t\t\t}}").unwrap();
1839 } else if let syn::Fields::Unnamed(fields) = &var.fields {
1840 if !empty_tuple_variant || !$to_c {
1841 write!(w, " (").unwrap();
1842 for (idx, field) in fields.unnamed.iter().enumerate() {
1843 write!(w, "\n\t\t\t\t\t").unwrap();
1844 handle_field_b!(field, &format_ident!("{}", ('a' as u8 + idx as u8) as char));
1846 writeln!(w, "\n\t\t\t\t)").unwrap();
1848 write!(w, "\t\t\t}}").unwrap();
1850 writeln!(w, ",").unwrap();
1852 writeln!(w, "\t\t}}\n\t}}").unwrap();
1857 write_conv!(format!("to_native(&self) -> native{}", e.ident), false, true);
1859 write_conv!(format!("into_native(self) -> native{}", e.ident), false, false);
1861 write_conv!(format!("from_native(native: &native{}) -> Self", e.ident), true, true);
1863 write_conv!(format!("native_into(native: native{}) -> Self", e.ident), true, false);
1864 writeln!(w, "}}").unwrap();
1867 writeln!(w, "/// Frees any resources used by the {}", e.ident).unwrap();
1868 writeln!(w, "#[no_mangle]\npub extern \"C\" fn {}_free(this_ptr: {}) {{ }}", e.ident, e.ident).unwrap();
1871 writeln!(w, "/// Creates a copy of the {}", e.ident).unwrap();
1872 writeln!(w, "#[no_mangle]").unwrap();
1873 writeln!(w, "pub extern \"C\" fn {}_clone(orig: &{}) -> {} {{", e.ident, e.ident, e.ident).unwrap();
1874 writeln!(w, "\torig.clone()").unwrap();
1875 writeln!(w, "}}").unwrap();
1877 w.write_all(&constr).unwrap();
1878 write_cpp_wrapper(cpp_headers, &format!("{}", e.ident), needs_free, None);
1881 fn writeln_fn<'a, 'b, W: std::io::Write>(w: &mut W, f: &'a syn::ItemFn, types: &mut TypeResolver<'b, 'a>) {
1882 match export_status(&f.attrs) {
1883 ExportStatus::Export => {},
1884 ExportStatus::NoExport|ExportStatus::TestOnly => return,
1885 ExportStatus::NotImplementable => panic!("(C-not implementable) must only appear on traits"),
1887 let mut gen_types = GenericTypes::new(None);
1888 if !gen_types.learn_generics(&f.sig.generics, types) { return; }
1890 writeln_fn_docs(w, &f.attrs, "", types, Some(&gen_types), f.sig.inputs.iter(), &f.sig.output);
1892 write!(w, "#[no_mangle]\npub extern \"C\" fn {}(", f.sig.ident).unwrap();
1895 write_method_params(w, &f.sig, "", types, Some(&gen_types), false, true);
1896 write!(w, " {{\n\t").unwrap();
1897 write_method_var_decl_body(w, &f.sig, "", types, Some(&gen_types), false);
1898 write!(w, "{}::{}", types.module_path, f.sig.ident).unwrap();
1900 let mut function_generic_args = Vec::new();
1901 maybe_write_generics(&mut function_generic_args, &f.sig.generics, types, true);
1902 if !function_generic_args.is_empty() {
1903 write!(w, "::{}", String::from_utf8(function_generic_args).unwrap()).unwrap();
1905 write!(w, "(").unwrap();
1907 write_method_call_params(w, &f.sig, "", types, Some(&gen_types), "", false);
1908 writeln!(w, "\n}}\n").unwrap();
1911 // ********************************
1912 // *** File/Crate Walking Logic ***
1913 // ********************************
1915 fn convert_priv_mod<'a, 'b: 'a, W: std::io::Write>(w: &mut W, libast: &'b FullLibraryAST, crate_types: &CrateTypes<'b>, out_dir: &str, mod_path: &str, module: &'b syn::ItemMod) {
1916 // We want to ignore all items declared in this module (as they are not pub), but we still need
1917 // to give the ImportResolver any use statements, so we copy them here.
1918 let mut use_items = Vec::new();
1919 for item in module.content.as_ref().unwrap().1.iter() {
1920 if let syn::Item::Use(_) = item {
1921 use_items.push(item);
1924 let import_resolver = ImportResolver::from_borrowed_items(mod_path.splitn(2, "::").next().unwrap(), &libast.dependencies, mod_path, &use_items);
1925 let mut types = TypeResolver::new(mod_path, import_resolver, crate_types);
1927 writeln!(w, "mod {} {{\n{}", module.ident, DEFAULT_IMPORTS).unwrap();
1928 for item in module.content.as_ref().unwrap().1.iter() {
1930 syn::Item::Mod(m) => convert_priv_mod(w, libast, crate_types, out_dir, &format!("{}::{}", mod_path, module.ident), m),
1931 syn::Item::Impl(i) => {
1932 writeln_impl(w, i, &mut types);
1937 writeln!(w, "}}").unwrap();
1940 /// Do the Real Work of mapping an original file to C-callable wrappers. Creates a new file at
1941 /// `out_path` and fills it with wrapper structs/functions to allow calling the things in the AST
1942 /// at `module` from C.
1943 fn convert_file<'a, 'b>(libast: &'a FullLibraryAST, crate_types: &CrateTypes<'a>, out_dir: &str, header_file: &mut File, cpp_header_file: &mut File) {
1944 for (module, astmod) in libast.modules.iter() {
1945 let orig_crate = module.splitn(2, "::").next().unwrap();
1946 let ASTModule { ref attrs, ref items, ref submods } = astmod;
1947 assert_eq!(export_status(&attrs), ExportStatus::Export);
1949 let new_file_path = if submods.is_empty() {
1950 format!("{}/{}.rs", out_dir, module.replace("::", "/"))
1951 } else if module != "" {
1952 format!("{}/{}/mod.rs", out_dir, module.replace("::", "/"))
1954 format!("{}/lib.rs", out_dir)
1956 let _ = std::fs::create_dir((&new_file_path.as_ref() as &std::path::Path).parent().unwrap());
1957 let mut out = std::fs::OpenOptions::new().write(true).create(true).truncate(true)
1958 .open(new_file_path).expect("Unable to open new src file");
1960 writeln!(out, "// This file is Copyright its original authors, visible in version control").unwrap();
1961 writeln!(out, "// history and in the source files from which this was generated.").unwrap();
1962 writeln!(out, "//").unwrap();
1963 writeln!(out, "// This file is licensed under the license available in the LICENSE or LICENSE.md").unwrap();
1964 writeln!(out, "// file in the root of this repository or, if no such file exists, the same").unwrap();
1965 writeln!(out, "// license as that which applies to the original source files from which this").unwrap();
1966 writeln!(out, "// source was automatically generated.").unwrap();
1967 writeln!(out, "").unwrap();
1969 writeln_docs(&mut out, &attrs, "");
1972 // Special-case the top-level lib.rs with various lint allows and a pointer to the c_types
1973 // and bitcoin hand-written modules.
1974 writeln!(out, "//! C Bindings").unwrap();
1975 writeln!(out, "#![allow(unknown_lints)]").unwrap();
1976 writeln!(out, "#![allow(non_camel_case_types)]").unwrap();
1977 writeln!(out, "#![allow(non_snake_case)]").unwrap();
1978 writeln!(out, "#![allow(unused_imports)]").unwrap();
1979 writeln!(out, "#![allow(unused_variables)]").unwrap();
1980 writeln!(out, "#![allow(unused_mut)]").unwrap();
1981 writeln!(out, "#![allow(unused_parens)]").unwrap();
1982 writeln!(out, "#![allow(unused_unsafe)]").unwrap();
1983 writeln!(out, "#![allow(unused_braces)]").unwrap();
1984 // TODO: We need to map deny(missing_docs) in the source crate(s)
1985 //writeln!(out, "#![deny(missing_docs)]").unwrap();
1987 writeln!(out, "#![cfg_attr(not(feature = \"std\"), no_std)]").unwrap();
1988 writeln!(out, "#[cfg(not(any(feature = \"std\", feature = \"no-std\")))]").unwrap();
1989 writeln!(out, "compile_error!(\"at least one of the `std` or `no-std` features must be enabled\");").unwrap();
1990 writeln!(out, "extern crate alloc;").unwrap();
1992 writeln!(out, "pub mod version;").unwrap();
1993 writeln!(out, "pub mod c_types;").unwrap();
1994 writeln!(out, "pub mod bitcoin;").unwrap();
1996 writeln!(out, "{}", DEFAULT_IMPORTS).unwrap();
2000 writeln!(out, "pub mod {};", m).unwrap();
2003 eprintln!("Converting {} entries...", module);
2005 let import_resolver = ImportResolver::new(orig_crate, &libast.dependencies, module, items);
2006 let mut type_resolver = TypeResolver::new(module, import_resolver, crate_types);
2008 for item in items.iter() {
2010 syn::Item::Use(_) => {}, // Handled above
2011 syn::Item::Static(_) => {},
2012 syn::Item::Enum(e) => {
2013 if let syn::Visibility::Public(_) = e.vis {
2014 writeln_enum(&mut out, &e, &mut type_resolver, header_file, cpp_header_file);
2017 syn::Item::Impl(i) => {
2018 writeln_impl(&mut out, &i, &mut type_resolver);
2020 syn::Item::Struct(s) => {
2021 if let syn::Visibility::Public(_) = s.vis {
2022 writeln_struct(&mut out, &s, &mut type_resolver, header_file, cpp_header_file);
2025 syn::Item::Trait(t) => {
2026 if let syn::Visibility::Public(_) = t.vis {
2027 writeln_trait(&mut out, &t, &mut type_resolver, header_file, cpp_header_file);
2030 syn::Item::Mod(m) => {
2031 convert_priv_mod(&mut out, libast, crate_types, out_dir, &format!("{}::{}", module, m.ident), m);
2033 syn::Item::Const(c) => {
2034 // Re-export any primitive-type constants.
2035 if let syn::Visibility::Public(_) = c.vis {
2036 if let syn::Type::Path(p) = &*c.ty {
2037 let resolved_path = type_resolver.resolve_path(&p.path, None);
2038 if type_resolver.is_primitive(&resolved_path) {
2039 writeln_field_docs(&mut out, &c.attrs, "", &mut type_resolver, None, &*c.ty);
2040 writeln!(out, "\n#[no_mangle]").unwrap();
2041 writeln!(out, "pub static {}: {} = {}::{};", c.ident, resolved_path, module, c.ident).unwrap();
2046 syn::Item::Type(t) => {
2047 if let syn::Visibility::Public(_) = t.vis {
2048 match export_status(&t.attrs) {
2049 ExportStatus::Export => {},
2050 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
2051 ExportStatus::NotImplementable => panic!("(C-not implementable) must only appear on traits"),
2055 syn::Type::Path(p) => {
2056 let real_ty = type_resolver.resolve_path(&p.path, None);
2057 let real_generic_bounds = type_resolver.crate_types.opaques.get(&real_ty).map(|t| t.1).or(
2058 type_resolver.crate_types.priv_structs.get(&real_ty).map(|r| *r)).unwrap();
2059 let mut resolved_generics = t.generics.clone();
2061 // Assume blindly that the bounds in the struct definition where
2062 // clause matches any equivalent bounds on the type alias.
2063 assert!(resolved_generics.where_clause.is_none());
2064 resolved_generics.where_clause = real_generic_bounds.where_clause.clone();
2066 if let syn::PathArguments::AngleBracketed(real_generics) = &p.path.segments.last().unwrap().arguments {
2067 for (real_idx, real_param) in real_generics.args.iter().enumerate() {
2068 if let syn::GenericArgument::Type(syn::Type::Path(real_param_path)) = real_param {
2069 for param in resolved_generics.params.iter_mut() {
2070 if let syn::GenericParam::Type(type_param) = param {
2071 if Some(&type_param.ident) == real_param_path.path.get_ident() {
2072 if let syn::GenericParam::Type(real_type_param) = &real_generic_bounds.params[real_idx] {
2073 type_param.bounds = real_type_param.bounds.clone();
2074 type_param.default = real_type_param.default.clone();
2084 writeln_opaque(&mut out, &t.ident, &format!("{}", t.ident), &resolved_generics, &t.attrs, &type_resolver, header_file, cpp_header_file)},
2089 syn::Item::Fn(f) => {
2090 if let syn::Visibility::Public(_) = f.vis {
2091 writeln_fn(&mut out, &f, &mut type_resolver);
2094 syn::Item::Macro(_) => {},
2095 syn::Item::Verbatim(_) => {},
2096 syn::Item::ExternCrate(_) => {},
2097 _ => unimplemented!(),
2101 out.flush().unwrap();
2106 /// Walk the FullLibraryAST, determining if impl aliases need to be marked cloneable.
2107 fn walk_ast_second_pass<'a>(ast_storage: &'a FullLibraryAST, crate_types: &CrateTypes<'a>) {
2108 for (module, astmod) in ast_storage.modules.iter() {
2109 let orig_crate = module.splitn(2, "::").next().unwrap();
2110 let ASTModule { ref attrs, ref items, .. } = astmod;
2111 assert_eq!(export_status(&attrs), ExportStatus::Export);
2113 let import_resolver = ImportResolver::new(orig_crate, &ast_storage.dependencies, module, items);
2114 let mut types = TypeResolver::new(module, import_resolver, crate_types);
2116 for item in items.iter() {
2118 syn::Item::Impl(i) => {
2119 match export_status(&i.attrs) {
2120 ExportStatus::Export => {},
2121 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
2122 ExportStatus::NotImplementable => panic!("(C-not implementable) must only appear on traits"),
2124 if let Some(trait_path) = i.trait_.as_ref() {
2125 if path_matches_nongeneric(&trait_path.1, &["core", "clone", "Clone"]) ||
2126 path_matches_nongeneric(&trait_path.1, &["Clone"])
2128 if let &syn::Type::Path(ref p) = &*i.self_ty {
2129 if let Some(resolved_path) = types.maybe_resolve_path(&p.path, None) {
2130 create_alias_for_impl(resolved_path, i, &mut types, |aliased_impl, types| {
2131 if let &syn::Type::Path(ref p) = &*aliased_impl.self_ty {
2132 if let Some(resolved_aliased_path) = types.maybe_resolve_path(&p.path, None) {
2133 crate_types.set_clonable("crate::".to_owned() + &resolved_aliased_path);
2148 fn walk_private_mod<'a>(ast_storage: &'a FullLibraryAST, orig_crate: &str, module: String, items: &'a syn::ItemMod, crate_types: &mut CrateTypes<'a>) {
2149 let import_resolver = ImportResolver::new(orig_crate, &ast_storage.dependencies, &module, &items.content.as_ref().unwrap().1);
2150 for item in items.content.as_ref().unwrap().1.iter() {
2152 syn::Item::Mod(m) => walk_private_mod(ast_storage, orig_crate, format!("{}::{}", module, m.ident), m, crate_types),
2153 syn::Item::Impl(i) => {
2154 if let &syn::Type::Path(ref p) = &*i.self_ty {
2155 if let Some(trait_path) = i.trait_.as_ref() {
2156 if let Some(tp) = import_resolver.maybe_resolve_path(&trait_path.1, None) {
2157 if let Some(sp) = import_resolver.maybe_resolve_path(&p.path, None) {
2158 match crate_types.trait_impls.entry(sp) {
2159 hash_map::Entry::Occupied(mut e) => { e.get_mut().push(tp); },
2160 hash_map::Entry::Vacant(e) => { e.insert(vec![tp]); },
2172 /// Walk the FullLibraryAST, deciding how things will be mapped and adding tracking to CrateTypes.
2173 fn walk_ast_first_pass<'a>(ast_storage: &'a FullLibraryAST, crate_types: &mut CrateTypes<'a>) {
2174 for (module, astmod) in ast_storage.modules.iter() {
2175 let ASTModule { ref attrs, ref items, submods: _ } = astmod;
2176 assert_eq!(export_status(&attrs), ExportStatus::Export);
2177 let orig_crate = module.splitn(2, "::").next().unwrap();
2178 let import_resolver = ImportResolver::new(orig_crate, &ast_storage.dependencies, module, items);
2180 for item in items.iter() {
2182 syn::Item::Struct(s) => {
2183 if let syn::Visibility::Public(_) = s.vis {
2184 let struct_path = format!("{}::{}", module, s.ident);
2185 match export_status(&s.attrs) {
2186 ExportStatus::Export => {},
2187 ExportStatus::NoExport|ExportStatus::TestOnly => {
2188 crate_types.priv_structs.insert(struct_path, &s.generics);
2191 ExportStatus::NotImplementable => panic!("(C-not implementable) must only appear on traits"),
2193 crate_types.opaques.insert(struct_path, (&s.ident, &s.generics));
2196 syn::Item::Trait(t) => {
2197 if let syn::Visibility::Public(_) = t.vis {
2198 match export_status(&t.attrs) {
2199 ExportStatus::Export|ExportStatus::NotImplementable => {},
2200 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
2202 let trait_path = format!("{}::{}", module, t.ident);
2203 walk_supertraits!(t, None, (
2205 crate_types.set_clonable("crate::".to_owned() + &trait_path);
2209 crate_types.traits.insert(trait_path, &t);
2212 syn::Item::Type(t) => {
2213 if let syn::Visibility::Public(_) = t.vis {
2214 match export_status(&t.attrs) {
2215 ExportStatus::Export => {},
2216 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
2217 ExportStatus::NotImplementable => panic!("(C-not implementable) must only appear on traits"),
2219 let type_path = format!("{}::{}", module, t.ident);
2221 syn::Type::Path(p) => {
2222 // If its a path with no generics, assume we don't map the aliased type and map it opaque
2223 let args_obj = p.path.segments.last().unwrap().arguments.clone();
2224 match crate_types.reverse_alias_map.entry(import_resolver.maybe_resolve_path(&p.path, None).unwrap()) {
2225 hash_map::Entry::Occupied(mut e) => { e.get_mut().push((type_path.clone(), args_obj)); },
2226 hash_map::Entry::Vacant(e) => { e.insert(vec![(type_path.clone(), args_obj)]); },
2229 crate_types.opaques.insert(type_path, (&t.ident, &t.generics));
2232 crate_types.type_aliases.insert(type_path, import_resolver.resolve_imported_refs((*t.ty).clone()));
2237 syn::Item::Enum(e) if is_enum_opaque(e) => {
2238 if let syn::Visibility::Public(_) = e.vis {
2239 match export_status(&e.attrs) {
2240 ExportStatus::Export => {},
2241 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
2242 ExportStatus::NotImplementable => panic!("(C-not implementable) must only appear on traits"),
2244 let enum_path = format!("{}::{}", module, e.ident);
2245 crate_types.opaques.insert(enum_path, (&e.ident, &e.generics));
2248 syn::Item::Enum(e) => {
2249 if let syn::Visibility::Public(_) = e.vis {
2250 match export_status(&e.attrs) {
2251 ExportStatus::Export => {},
2252 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
2253 ExportStatus::NotImplementable => panic!("(C-not implementable) must only appear on traits"),
2255 let enum_path = format!("{}::{}", module, e.ident);
2256 crate_types.mirrored_enums.insert(enum_path, &e);
2259 syn::Item::Impl(i) => {
2260 if let &syn::Type::Path(ref p) = &*i.self_ty {
2261 if let Some(trait_path) = i.trait_.as_ref() {
2262 if path_matches_nongeneric(&trait_path.1, &["core", "clone", "Clone"]) ||
2263 path_matches_nongeneric(&trait_path.1, &["Clone"]) {
2264 if let Some(full_path) = import_resolver.maybe_resolve_path(&p.path, None) {
2265 crate_types.set_clonable("crate::".to_owned() + &full_path);
2268 if let Some(tp) = import_resolver.maybe_resolve_path(&trait_path.1, None) {
2269 if let Some(sp) = import_resolver.maybe_resolve_path(&p.path, None) {
2270 match crate_types.trait_impls.entry(sp) {
2271 hash_map::Entry::Occupied(mut e) => { e.get_mut().push(tp); },
2272 hash_map::Entry::Vacant(e) => { e.insert(vec![tp]); },
2279 syn::Item::Mod(m) => walk_private_mod(ast_storage, orig_crate, format!("{}::{}", module, m.ident), m, crate_types),
2287 let args: Vec<String> = env::args().collect();
2288 if args.len() != 5 {
2289 eprintln!("Usage: target/dir derived_templates.rs extra/includes.h extra/cpp/includes.hpp");
2293 let mut derived_templates = std::fs::OpenOptions::new().write(true).create(true).truncate(true)
2294 .open(&args[2]).expect("Unable to open new header file");
2295 writeln!(&mut derived_templates, "{}", DEFAULT_IMPORTS).unwrap();
2296 let mut header_file = std::fs::OpenOptions::new().write(true).create(true).truncate(true)
2297 .open(&args[3]).expect("Unable to open new header file");
2298 let mut cpp_header_file = std::fs::OpenOptions::new().write(true).create(true).truncate(true)
2299 .open(&args[4]).expect("Unable to open new header file");
2301 writeln!(header_file, "#if defined(__GNUC__)").unwrap();
2302 writeln!(header_file, "#define MUST_USE_STRUCT __attribute__((warn_unused))").unwrap();
2303 writeln!(header_file, "#define MUST_USE_RES __attribute__((warn_unused_result))").unwrap();
2304 writeln!(header_file, "#else").unwrap();
2305 writeln!(header_file, "#define MUST_USE_STRUCT").unwrap();
2306 writeln!(header_file, "#define MUST_USE_RES").unwrap();
2307 writeln!(header_file, "#endif").unwrap();
2308 writeln!(header_file, "#if defined(__clang__)").unwrap();
2309 writeln!(header_file, "#define NONNULL_PTR _Nonnull").unwrap();
2310 writeln!(header_file, "#else").unwrap();
2311 writeln!(header_file, "#define NONNULL_PTR").unwrap();
2312 writeln!(header_file, "#endif").unwrap();
2313 writeln!(cpp_header_file, "#include <string.h>\nnamespace LDK {{").unwrap();
2315 // Write a few manually-defined types into the C++ header file
2316 write_cpp_wrapper(&mut cpp_header_file, "Str", true, None);
2318 // First parse the full crate's ASTs, caching them so that we can hold references to the AST
2319 // objects in other datastructures:
2320 let mut lib_src = String::new();
2321 std::io::stdin().lock().read_to_string(&mut lib_src).unwrap();
2322 let lib_syntax = syn::parse_file(&lib_src).expect("Unable to parse file");
2323 let libast = FullLibraryAST::load_lib(lib_syntax);
2325 // ...then walk the ASTs tracking what types we will map, and how, so that we can resolve them
2326 // when parsing other file ASTs...
2327 let mut libtypes = CrateTypes::new(&mut derived_templates, &libast);
2328 walk_ast_first_pass(&libast, &mut libtypes);
2330 // ... using the generated data, determine a few additional fields, specifically which type
2331 // aliases are to be clone-able...
2332 walk_ast_second_pass(&libast, &libtypes);
2334 // ... finally, do the actual file conversion/mapping, writing out types as we go.
2335 convert_file(&libast, &libtypes, &args[1], &mut header_file, &mut cpp_header_file);
2337 // For container templates which we created while walking the crate, make sure we add C++
2338 // mapped types so that C++ users can utilize the auto-destructors available.
2339 for (ty, has_destructor) in libtypes.templates_defined.borrow().iter() {
2340 write_cpp_wrapper(&mut cpp_header_file, ty, *has_destructor, None);
2342 writeln!(cpp_header_file, "}}").unwrap();
2344 header_file.flush().unwrap();
2345 cpp_header_file.flush().unwrap();
2346 derived_templates.flush().unwrap();