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, HashSet};
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 let last_seg = supertrait.path.segments.iter().last().unwrap();
248 match (&path as &str, &last_seg.ident, &last_seg.arguments) {
249 $( $($pat)|* => $e, )*
254 if let Some(ident) = supertrait.path.get_ident() {
255 match (&format!("{}", ident) as &str, &ident, &syn::PathArguments::None) {
256 $( $($pat)|* => $e, )*
258 } else if types_opt.is_some() {
259 panic!("Supertrait unresolvable and not single-ident");
262 syn::TypeParamBound::Lifetime(_) => unimplemented!(),
268 macro_rules! get_module_type_resolver {
269 ($module: expr, $crate_libs: expr, $crate_types: expr) => { {
270 let module: &str = &$module;
271 let mut module_iter = module.rsplitn(2, "::");
272 module_iter.next().unwrap();
273 let module = module_iter.next().unwrap();
274 let imports = ImportResolver::new(module.splitn(2, "::").next().unwrap(), &$crate_types.lib_ast,
275 module, &$crate_types.lib_ast.modules.get(module).unwrap().items);
276 TypeResolver::new(module, imports, $crate_types)
280 /// Prints a C-mapped trait object containing a void pointer and a jump table for each function in
281 /// the original trait.
282 /// Implements the native Rust trait and relevant parent traits for the new C-mapped trait.
284 /// Finally, implements Deref<MappedTrait> for MappedTrait which allows its use in types which need
285 /// a concrete Deref to the Rust trait.
286 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) {
287 let trait_name = format!("{}", t.ident);
289 match export_status(&t.attrs) {
290 ExportStatus::Export => { implementable = true; }
291 ExportStatus::NotImplementable => { implementable = false; },
292 ExportStatus::NoExport|ExportStatus::TestOnly => return,
294 writeln_docs(w, &t.attrs, "");
296 let mut gen_types = GenericTypes::new(Some(format!("{}::{}", types.module_path, trait_name)));
298 // Add functions which may be required for supertrait implementations.
299 // Due to borrow checker limitations, we only support one in-crate supertrait here.
301 let supertrait_resolver;
302 walk_supertraits!(t, Some(&types), (
304 if let Some(supertrait) = types.crate_types.traits.get(s) {
305 supertrait_name = s.to_string();
306 supertrait_resolver = get_module_type_resolver!(supertrait_name, types.crate_libs, types.crate_types);
307 gen_types.learn_associated_types(&supertrait, &supertrait_resolver);
313 assert!(gen_types.learn_generics(&t.generics, types));
314 gen_types.learn_associated_types(&t, types);
316 writeln!(w, "#[repr(C)]\npub struct {} {{", trait_name).unwrap();
317 writeln!(w, "\t/// An opaque pointer which is passed to your function implementations as an argument.").unwrap();
318 writeln!(w, "\t/// This has no meaning in the LDK, and can be NULL or any other value.").unwrap();
319 writeln!(w, "\tpub this_arg: *mut c_void,").unwrap();
320 // We store every field's (name, Option<clone_fn>, docs) except this_arg, used in Clone generation
321 // docs is only set if its a function which should be callable on the object itself in C++
322 let mut generated_fields = Vec::new();
323 for item in t.items.iter() {
325 &syn::TraitItem::Method(ref m) => {
326 match export_status(&m.attrs) {
327 ExportStatus::NoExport => {
328 // NoExport in this context means we'll hit an unimplemented!() at runtime,
332 ExportStatus::Export => {},
333 ExportStatus::TestOnly => continue,
334 ExportStatus::NotImplementable => panic!("(C-not implementable) must only appear on traits"),
337 let mut meth_gen_types = gen_types.push_ctx();
338 assert!(meth_gen_types.learn_generics(&m.sig.generics, types));
340 writeln_fn_docs(w, &m.attrs, "\t", types, Some(&meth_gen_types), m.sig.inputs.iter(), &m.sig.output);
342 if let syn::ReturnType::Type(_, rtype) = &m.sig.output {
343 if let syn::Type::Reference(r) = &**rtype {
344 // We have to do quite a dance for trait functions which return references
345 // - they ultimately require us to have a native Rust object stored inside
346 // our concrete trait to return a reference to. However, users may wish to
347 // update the value to be returned each time the function is called (or, to
348 // make C copies of Rust impls equivalent, we have to be able to).
350 // Thus, we store a copy of the C-mapped type (which is just a pointer to
351 // the Rust type and a flag to indicate whether deallocation needs to
352 // happen) as well as provide an Option<>al function pointer which is
353 // called when the trait method is called which allows updating on the fly.
354 write!(w, "\tpub {}: core::cell::UnsafeCell<", m.sig.ident).unwrap();
355 generated_fields.push((format!("{}", m.sig.ident), Some(("Clone::clone(unsafe { &*core::cell::UnsafeCell::get(".to_owned(), ")}).into()")), None));
356 types.write_c_type(w, &*r.elem, Some(&meth_gen_types), false);
357 writeln!(w, ">,").unwrap();
358 writeln!(w, "\t/// Fill in the {} field as a reference to it will be given to Rust after this returns", m.sig.ident).unwrap();
359 writeln!(w, "\t/// Note that this takes a pointer to this object, not the this_ptr like other methods do").unwrap();
360 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();
361 writeln!(w, "\tpub set_{}: Option<extern \"C\" fn(&{})>,", m.sig.ident, trait_name).unwrap();
362 generated_fields.push((format!("set_{}", m.sig.ident), None, None));
363 // Note that cbindgen will now generate
364 // typedef struct Thing {..., set_thing: (const struct Thing*), ...} Thing;
365 // which does not compile since Thing is not defined before it is used.
366 writeln!(extra_headers, "struct LDK{};", trait_name).unwrap();
371 let mut cpp_docs = Vec::new();
372 writeln_fn_docs(&mut cpp_docs, &m.attrs, "\t * ", types, Some(&meth_gen_types), m.sig.inputs.iter(), &m.sig.output);
373 let docs_string = "\t/**\n".to_owned() + &String::from_utf8(cpp_docs).unwrap().replace("///", "") + "\t */\n";
375 write!(w, "\tpub {}: extern \"C\" fn (", m.sig.ident).unwrap();
376 generated_fields.push((format!("{}", m.sig.ident), None, Some(docs_string)));
377 write_method_params(w, &m.sig, "c_void", types, Some(&meth_gen_types), true, false);
378 writeln!(w, ",").unwrap();
380 &syn::TraitItem::Type(_) => {},
381 _ => unimplemented!(),
384 // Add functions which may be required for supertrait implementations.
385 walk_supertraits!(t, Some(&types), (
387 writeln!(w, "\t/// Called, if set, after this {} has been cloned into a duplicate object.", trait_name).unwrap();
388 writeln!(w, "\t/// The new {} is provided, and should be mutated as needed to perform a", trait_name).unwrap();
389 writeln!(w, "\t/// deep copy of the object pointed to by this_arg or avoid any double-freeing.").unwrap();
390 writeln!(w, "\tpub cloned: Option<extern \"C\" fn (new_{}: &mut {})>,", trait_name, trait_name).unwrap();
391 generated_fields.push(("cloned".to_owned(), None, None));
393 ("std::cmp::Eq", _, _)|("core::cmp::Eq", _, _) => {
394 let eq_docs = "Checks if two objects are equal given this object's this_arg pointer and another object.";
395 writeln!(w, "\t/// {}", eq_docs).unwrap();
396 writeln!(w, "\tpub eq: extern \"C\" fn (this_arg: *const c_void, other_arg: &{}) -> bool,", trait_name).unwrap();
397 generated_fields.push(("eq".to_owned(), None, Some(format!("\t/** {} */\n", eq_docs))));
399 ("std::hash::Hash", _, _)|("core::hash::Hash", _, _) => {
400 let hash_docs_a = "Calculate a succinct non-cryptographic hash for an object given its this_arg pointer.";
401 let hash_docs_b = "This is used, for example, for inclusion of this object in a hash map.";
402 writeln!(w, "\t/// {}", hash_docs_a).unwrap();
403 writeln!(w, "\t/// {}", hash_docs_b).unwrap();
404 writeln!(w, "\tpub hash: extern \"C\" fn (this_arg: *const c_void) -> u64,").unwrap();
405 generated_fields.push(("hash".to_owned(), None,
406 Some(format!("\t/**\n\t * {}\n\t * {}\n\t */\n", hash_docs_a, hash_docs_b))));
408 ("Send", _, _) => {}, ("Sync", _, _) => {},
409 ("std::fmt::Debug", _, _)|("core::fmt::Debug", _, _) => {
410 let debug_docs = "Return a human-readable \"debug\" string describing this object";
411 writeln!(w, "\t/// {}", debug_docs).unwrap();
412 writeln!(w, "\tpub debug_str: extern \"C\" fn (this_arg: *const c_void) -> crate::c_types::Str,").unwrap();
413 generated_fields.push(("debug_str".to_owned(), None,
414 Some(format!("\t/**\n\t * {}\n\t */\n", debug_docs))));
417 // TODO: Both of the below should expose supertrait methods in C++, but doing so is
419 generated_fields.push(if types.crate_types.traits.get(s).is_none() {
420 let (docs, name, ret) = convert_trait_impl_field(s);
421 writeln!(w, "\t/// {}", docs).unwrap();
422 writeln!(w, "\tpub {}: extern \"C\" fn (this_arg: *const c_void) -> {},", name, ret).unwrap();
423 (name, None, None) // Assume clonable
425 // For in-crate supertraits, just store a C-mapped copy of the supertrait as a member.
426 writeln!(w, "\t/// Implementation of {} for this object.", i).unwrap();
427 let is_clonable = types.is_clonable(s);
428 writeln!(w, "\tpub {}: crate::{},", i, s).unwrap();
429 (format!("{}", i), if !is_clonable {
430 Some((format!("crate::{}_clone_fields(", s), ")"))
431 } else { None }, None)
435 writeln!(w, "\t/// Frees any resources associated with this object given its this_arg pointer.").unwrap();
436 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();
437 writeln!(w, "\tpub free: Option<extern \"C\" fn(this_arg: *mut c_void)>,").unwrap();
438 generated_fields.push(("free".to_owned(), None, None));
439 writeln!(w, "}}").unwrap();
441 macro_rules! impl_trait_for_c {
442 ($t: expr, $impl_accessor: expr, $type_resolver: expr, $generic_impls: expr) => {
443 let mut trait_gen_types = gen_types.push_ctx();
444 assert!(trait_gen_types.learn_generics_with_impls(&$t.generics, $generic_impls, $type_resolver));
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 = trait_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, "unsafe {{ &*self{}.{}.get() }}", $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((pfx, sfx)) = 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, pfx, field, sfx).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();
597 (s, i, generic_args) => {
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);
600 macro_rules! impl_supertrait {
601 ($s: expr, $supertrait: expr, $i: expr, $generic_args: expr) => {
602 let resolver = get_module_type_resolver!($s, types.crate_libs, types.crate_types);
604 // Blindly assume that the same imports where `supertrait` is defined are also
605 // imported here. This will almost certainly break at some point, but it should be
606 // a compilation failure when it does so.
607 write!(w, "impl").unwrap();
608 maybe_write_lifetime_generics(w, &$supertrait.generics, types);
609 write!(w, " {}", $s).unwrap();
610 maybe_write_generics(w, &$supertrait.generics, $generic_args, types, false);
611 writeln!(w, " for {} {{", trait_name).unwrap();
613 impl_trait_for_c!($supertrait, format!(".{}", $i), &resolver, $generic_args);
614 writeln!(w, "}}").unwrap();
617 impl_supertrait!(s, supertrait, i, generic_args);
618 walk_supertraits!(supertrait, Some(&resolver), (
619 (s, supertrait_i, generic_args) => {
620 if let Some(supertrait) = types.crate_types.traits.get(s) {
621 impl_supertrait!(s, supertrait, format!("{}.{}", i, supertrait_i), generic_args);
626 do_write_impl_trait(w, s, i, &trait_name);
631 // Finally, implement the original Rust trait for the newly created mapped trait.
632 writeln!(w, "\nuse {}::{} as rust{};", types.module_path, t.ident, trait_name).unwrap();
634 write!(w, "impl").unwrap();
635 maybe_write_lifetime_generics(w, &t.generics, types);
636 write!(w, " rust{}", t.ident).unwrap();
637 maybe_write_generics(w, &t.generics, &syn::PathArguments::None, types, false);
638 writeln!(w, " for {} {{", trait_name).unwrap();
639 impl_trait_for_c!(t, "", types, &syn::PathArguments::None);
640 writeln!(w, "}}\n").unwrap();
641 writeln!(w, "// We're essentially a pointer already, or at least a set of pointers, so allow us to be used").unwrap();
642 writeln!(w, "// directly as a Deref trait in higher-level structs:").unwrap();
643 writeln!(w, "impl core::ops::Deref for {} {{\n\ttype Target = Self;", trait_name).unwrap();
644 writeln!(w, "\tfn deref(&self) -> &Self {{\n\t\tself\n\t}}\n}}").unwrap();
647 writeln!(w, "/// Calls the free function if one is set").unwrap();
648 writeln!(w, "#[no_mangle]\npub extern \"C\" fn {}_free(this_ptr: {}) {{ }}", trait_name, trait_name).unwrap();
649 writeln!(w, "impl Drop for {} {{", trait_name).unwrap();
650 writeln!(w, "\tfn drop(&mut self) {{").unwrap();
651 writeln!(w, "\t\tif let Some(f) = self.free {{").unwrap();
652 writeln!(w, "\t\t\tf(self.this_arg);").unwrap();
653 writeln!(w, "\t\t}}\n\t}}\n}}").unwrap();
655 write_cpp_wrapper(cpp_headers, &trait_name, true, Some(generated_fields.drain(..)
656 .filter_map(|(name, _, docs)| if let Some(docs) = docs { Some((name, docs)) } else { None }).collect()));
659 /// Write out a simple "opaque" type (eg structs) which contain a pointer to the native Rust type
660 /// and a flag to indicate whether Drop'ing the mapped struct drops the underlying Rust type.
662 /// Also writes out a _free function and a C++ wrapper which handles calling _free.
663 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) {
664 // If we directly read the original type by its original name, cbindgen hits
665 // https://github.com/eqrion/cbindgen/issues/286 Thus, instead, we import it as a temporary
666 // name and then reference it by that name, which works around the issue.
667 write!(w, "\nuse {}::{} as native{}Import;\npub(crate) type native{} = native{}Import", types.module_path, ident, ident, ident, ident).unwrap();
668 maybe_write_generics(w, &generics, &syn::PathArguments::None, &types, true);
669 writeln!(w, ";\n").unwrap();
670 writeln!(extra_headers, "struct native{}Opaque;\ntypedef struct native{}Opaque LDKnative{};", ident, ident, ident).unwrap();
671 writeln_docs(w, &attrs, "");
672 writeln!(w, "#[must_use]\n#[repr(C)]\npub struct {} {{", struct_name).unwrap();
673 writeln!(w, "\t/// A pointer to the opaque Rust object.\n").unwrap();
674 writeln!(w, "\t/// Nearly everywhere, inner must be non-null, however in places where").unwrap();
675 writeln!(w, "\t/// the Rust equivalent takes an Option, it may be set to null to indicate None.").unwrap();
676 writeln!(w, "\tpub inner: *mut native{},", ident).unwrap();
677 writeln!(w, "\t/// Indicates that this is the only struct which contains the same pointer.\n").unwrap();
678 writeln!(w, "\t/// Rust functions which take ownership of an object provided via an argument require").unwrap();
679 writeln!(w, "\t/// this to be true and invalidate the object pointed to by inner.").unwrap();
680 writeln!(w, "\tpub is_owned: bool,").unwrap();
681 writeln!(w, "}}\n").unwrap();
682 writeln!(w, "impl Drop for {} {{\n\tfn drop(&mut self) {{", struct_name).unwrap();
683 writeln!(w, "\t\tif self.is_owned && !<*mut native{}>::is_null(self.inner) {{", ident).unwrap();
684 writeln!(w, "\t\t\tlet _ = unsafe {{ Box::from_raw(ObjOps::untweak_ptr(self.inner)) }};\n\t\t}}\n\t}}\n}}").unwrap();
685 writeln!(w, "/// Frees any resources used by the {}, if is_owned is set and inner is non-NULL.", struct_name).unwrap();
686 writeln!(w, "#[no_mangle]\npub extern \"C\" fn {}_free(this_obj: {}) {{ }}", struct_name, struct_name).unwrap();
687 writeln!(w, "#[allow(unused)]").unwrap();
688 writeln!(w, "/// Used only if an object of this type is returned as a trait impl by a method").unwrap();
689 writeln!(w, "pub(crate) extern \"C\" fn {}_free_void(this_ptr: *mut c_void) {{", struct_name).unwrap();
690 writeln!(w, "\tlet _ = unsafe {{ Box::from_raw(this_ptr as *mut native{}) }};\n}}", struct_name).unwrap();
691 writeln!(w, "#[allow(unused)]").unwrap();
692 writeln!(w, "impl {} {{", struct_name).unwrap();
693 writeln!(w, "\tpub(crate) fn get_native_ref(&self) -> &'static native{} {{", struct_name).unwrap();
694 writeln!(w, "\t\tunsafe {{ &*ObjOps::untweak_ptr(self.inner) }}").unwrap();
695 writeln!(w, "\t}}").unwrap();
696 writeln!(w, "\tpub(crate) fn get_native_mut_ref(&self) -> &'static mut native{} {{", struct_name).unwrap();
697 writeln!(w, "\t\tunsafe {{ &mut *ObjOps::untweak_ptr(self.inner) }}").unwrap();
698 writeln!(w, "\t}}").unwrap();
699 writeln!(w, "\t/// When moving out of the pointer, we have to ensure we aren't a reference, this makes that easy").unwrap();
700 writeln!(w, "\tpub(crate) fn take_inner(mut self) -> *mut native{} {{", struct_name).unwrap();
701 writeln!(w, "\t\tassert!(self.is_owned);").unwrap();
702 writeln!(w, "\t\tlet ret = ObjOps::untweak_ptr(self.inner);").unwrap();
703 writeln!(w, "\t\tself.inner = core::ptr::null_mut();").unwrap();
704 writeln!(w, "\t\tret").unwrap();
705 writeln!(w, "\t}}\n}}").unwrap();
707 write_cpp_wrapper(cpp_headers, &format!("{}", ident), true, None);
710 /// Writes out all the relevant mappings for a Rust struct, deferring to writeln_opaque to generate
711 /// the struct itself, and then writing getters and setters for public, understood-type fields and
712 /// a constructor if every field is public.
713 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) {
714 if export_status(&s.attrs) != ExportStatus::Export { return; }
716 let struct_name = &format!("{}", s.ident);
717 writeln_opaque(w, &s.ident, struct_name, &s.generics, &s.attrs, types, extra_headers, cpp_headers);
719 let mut self_path_segs = syn::punctuated::Punctuated::new();
720 self_path_segs.push(s.ident.clone().into());
721 let self_path = syn::Path { leading_colon: None, segments: self_path_segs};
722 let mut gen_types = GenericTypes::new(Some(types.resolve_path(&self_path, None)));
723 assert!(gen_types.learn_generics(&s.generics, types));
725 let mut all_fields_settable = true;
726 macro_rules! define_field {
727 ($new_name: expr, $real_name: expr, $field: expr) => {
728 if let syn::Visibility::Public(_) = $field.vis {
729 let export = export_status(&$field.attrs);
731 ExportStatus::Export => {},
732 ExportStatus::NoExport|ExportStatus::TestOnly => {
733 all_fields_settable = false;
736 ExportStatus::NotImplementable => panic!("(C-not implementable) must only appear on traits"),
739 if let Some(ref_type) = types.create_ownable_reference(&$field.ty, Some(&gen_types)) {
740 if types.understood_c_type(&ref_type, Some(&gen_types)) {
741 writeln_arg_docs(w, &$field.attrs, "", types, Some(&gen_types), vec![].drain(..), Some(&ref_type));
742 write!(w, "#[no_mangle]\npub extern \"C\" fn {}_get_{}(this_ptr: &{}) -> ", struct_name, $new_name, struct_name).unwrap();
743 types.write_c_type(w, &ref_type, Some(&gen_types), true);
744 write!(w, " {{\n\tlet mut inner_val = &mut this_ptr.get_native_mut_ref().{};\n\t", $real_name).unwrap();
745 let local_var = types.write_to_c_conversion_from_ownable_ref_new_var(w, &format_ident!("inner_val"), &ref_type, Some(&gen_types));
746 if local_var { write!(w, "\n\t").unwrap(); }
747 types.write_to_c_conversion_inline_prefix(w, &ref_type, Some(&gen_types), true);
748 write!(w, "inner_val").unwrap();
749 types.write_to_c_conversion_inline_suffix(w, &ref_type, Some(&gen_types), true);
750 writeln!(w, "\n}}").unwrap();
752 // If the type isn't reference-able, but is clonable, export a getter that just clones
753 if types.understood_c_type(&$field.ty, Some(&gen_types)) {
754 let mut v = Vec::new();
755 types.write_c_type(&mut v, &$field.ty, Some(&gen_types), true);
756 let s = String::from_utf8(v).unwrap();
757 if types.is_clonable(&s) {
758 writeln_arg_docs(w, &$field.attrs, "", types, Some(&gen_types), vec![].drain(..), Some(&$field.ty));
759 writeln!(w, "///\n/// Returns a copy of the field.").unwrap();
760 write!(w, "#[no_mangle]\npub extern \"C\" fn {}_get_{}(this_ptr: &{}) -> {}", struct_name, $new_name, struct_name, s).unwrap();
761 write!(w, " {{\n\tlet mut inner_val = this_ptr.get_native_mut_ref().{}.clone();\n\t", $real_name).unwrap();
762 let local_var = types.write_to_c_conversion_new_var(w, &format_ident!("inner_val"), &$field.ty, Some(&gen_types), true);
763 if local_var { write!(w, "\n\t").unwrap(); }
764 types.write_to_c_conversion_inline_prefix(w, &$field.ty, Some(&gen_types), true);
765 write!(w, "inner_val").unwrap();
766 types.write_to_c_conversion_inline_suffix(w, &$field.ty, Some(&gen_types), true);
767 writeln!(w, "\n}}").unwrap();
773 if types.understood_c_type(&$field.ty, Some(&gen_types)) {
774 writeln_arg_docs(w, &$field.attrs, "", types, Some(&gen_types), vec![("val".to_owned(), &$field.ty)].drain(..), None);
775 write!(w, "#[no_mangle]\npub extern \"C\" fn {}_set_{}(this_ptr: &mut {}, mut val: ", struct_name, $new_name, struct_name).unwrap();
776 types.write_c_type(w, &$field.ty, Some(&gen_types), false);
777 write!(w, ") {{\n\t").unwrap();
778 let local_var = types.write_from_c_conversion_new_var(w, &format_ident!("val"), &$field.ty, Some(&gen_types));
779 if local_var { write!(w, "\n\t").unwrap(); }
780 write!(w, "unsafe {{ &mut *ObjOps::untweak_ptr(this_ptr.inner) }}.{} = ", $real_name).unwrap();
781 types.write_from_c_conversion_prefix(w, &$field.ty, Some(&gen_types));
782 write!(w, "val").unwrap();
783 types.write_from_c_conversion_suffix(w, &$field.ty, Some(&gen_types));
784 writeln!(w, ";\n}}").unwrap();
785 } else { all_fields_settable = false; }
786 } else { all_fields_settable = false; }
791 syn::Fields::Named(fields) => {
792 for field in fields.named.iter() {
793 if let Some(ident) = &field.ident {
794 define_field!(ident, ident, field);
795 } else { all_fields_settable = false; }
798 syn::Fields::Unnamed(fields) => {
799 for (idx, field) in fields.unnamed.iter().enumerate() {
800 define_field!(('a' as u8 + idx as u8) as char, ('0' as u8 + idx as u8) as char, field);
803 _ => unimplemented!()
806 if all_fields_settable {
807 // Build a constructor!
808 writeln!(w, "/// Constructs a new {} given each field", struct_name).unwrap();
809 write!(w, "#[must_use]\n#[no_mangle]\npub extern \"C\" fn {}_new(", struct_name).unwrap();
812 syn::Fields::Named(fields) => {
813 for (idx, field) in fields.named.iter().enumerate() {
814 if idx != 0 { write!(w, ", ").unwrap(); }
815 write!(w, "mut {}_arg: ", field.ident.as_ref().unwrap()).unwrap();
816 types.write_c_type(w, &field.ty, Some(&gen_types), false);
819 syn::Fields::Unnamed(fields) => {
820 for (idx, field) in fields.unnamed.iter().enumerate() {
821 if idx != 0 { write!(w, ", ").unwrap(); }
822 write!(w, "mut {}_arg: ", ('a' as u8 + idx as u8) as char).unwrap();
823 types.write_c_type(w, &field.ty, Some(&gen_types), false);
828 write!(w, ") -> {} {{\n\t", struct_name).unwrap();
830 syn::Fields::Named(fields) => {
831 for field in fields.named.iter() {
832 let field_ident = format_ident!("{}_arg", field.ident.as_ref().unwrap());
833 if types.write_from_c_conversion_new_var(w, &field_ident, &field.ty, Some(&gen_types)) {
834 write!(w, "\n\t").unwrap();
838 syn::Fields::Unnamed(fields) => {
839 for (idx, field) in fields.unnamed.iter().enumerate() {
840 let field_ident = format_ident!("{}_arg", ('a' as u8 + idx as u8) as char);
841 if types.write_from_c_conversion_new_var(w, &field_ident, &field.ty, Some(&gen_types)) {
842 write!(w, "\n\t").unwrap();
848 write!(w, "{} {{ inner: ObjOps::heap_alloc(", struct_name).unwrap();
850 syn::Fields::Named(fields) => {
851 writeln!(w, "native{} {{", s.ident).unwrap();
852 for field in fields.named.iter() {
853 write!(w, "\t\t{}: ", field.ident.as_ref().unwrap()).unwrap();
854 types.write_from_c_conversion_prefix(w, &field.ty, Some(&gen_types));
855 write!(w, "{}_arg", field.ident.as_ref().unwrap()).unwrap();
856 types.write_from_c_conversion_suffix(w, &field.ty, Some(&gen_types));
857 writeln!(w, ",").unwrap();
859 write!(w, "\t}}").unwrap();
861 syn::Fields::Unnamed(fields) => {
862 assert!(!s.generics.params.iter()
863 .any(|gen| if let syn::GenericParam::Lifetime(_) = gen { false } else { true }));
864 writeln!(w, "{} (", types.maybe_resolve_ident(&s.ident).unwrap()).unwrap();
865 for (idx, field) in fields.unnamed.iter().enumerate() {
866 write!(w, "\t\t").unwrap();
867 types.write_from_c_conversion_prefix(w, &field.ty, Some(&gen_types));
868 write!(w, "{}_arg", ('a' as u8 + idx as u8) as char).unwrap();
869 types.write_from_c_conversion_suffix(w, &field.ty, Some(&gen_types));
870 writeln!(w, ",").unwrap();
872 write!(w, "\t)").unwrap();
876 writeln!(w, "), is_owned: true }}\n}}").unwrap();
880 /// Prints a relevant conversion for impl *
882 /// For simple impl Struct {}s, this just outputs the wrapper functions as Struct_fn_name() { .. }.
884 /// For impl Trait for Struct{}s, this non-exported generates wrapper functions as
885 /// Trait_Struct_fn_name and a Struct_as_Trait(&struct) -> Trait function which returns a populated
886 /// Trait struct containing a pointer to the passed struct's inner field and the wrapper functions.
888 /// A few non-crate Traits are hard-coded including Default.
889 fn writeln_impl<W: std::io::Write>(w: &mut W, w_uses: &mut HashSet<String, NonRandomHash>, i: &syn::ItemImpl, types: &mut TypeResolver) {
890 match export_status(&i.attrs) {
891 ExportStatus::Export => {},
892 ExportStatus::NoExport|ExportStatus::TestOnly => return,
893 ExportStatus::NotImplementable => panic!("(C-not implementable) must only appear on traits"),
896 if let syn::Type::Tuple(_) = &*i.self_ty {
897 if types.understood_c_type(&*i.self_ty, None) {
898 let mut gen_types = GenericTypes::new(None);
899 if !gen_types.learn_generics(&i.generics, types) {
900 eprintln!("Not implementing anything for `impl (..)` due to not understood generics");
904 if i.defaultness.is_some() || i.unsafety.is_some() { unimplemented!(); }
905 if let Some(trait_path) = i.trait_.as_ref() {
906 if trait_path.0.is_some() { unimplemented!(); }
907 if types.understood_c_path(&trait_path.1) {
908 eprintln!("Not implementing anything for `impl Trait for (..)` - we only support manual defines");
911 // Just do a manual implementation:
912 maybe_convert_trait_impl(w, &trait_path.1, &*i.self_ty, types, &gen_types);
915 eprintln!("Not implementing anything for plain `impl (..)` block - we only support `impl Trait for (..)` blocks");
921 if let &syn::Type::Path(ref p) = &*i.self_ty {
922 if p.qself.is_some() { unimplemented!(); }
923 let ident = &p.path.segments.last().unwrap().ident;
924 if let Some(resolved_path) = types.maybe_resolve_path(&p.path, None) {
925 if types.crate_types.opaques.contains_key(&resolved_path) || types.crate_types.mirrored_enums.contains_key(&resolved_path) ||
926 // At least for core::infallible::Infallible we need to support mapping an
927 // out-of-crate trait implementation.
928 (types.understood_c_path(&p.path) && first_seg_is_stdlib(resolved_path.split("::").next().unwrap())) {
929 if !types.understood_c_path(&p.path) {
930 eprintln!("Not implementing anything for impl {} as the type is not understood (probably C-not exported)", ident);
934 let mut gen_types = GenericTypes::new(Some(resolved_path.clone()));
935 if !gen_types.learn_generics(&i.generics, types) {
936 eprintln!("Not implementing anything for impl {} due to not understood generics", ident);
940 if i.defaultness.is_some() || i.unsafety.is_some() { unimplemented!(); }
941 if let Some(trait_path) = i.trait_.as_ref() {
942 if trait_path.0.is_some() { unimplemented!(); }
943 if types.understood_c_path(&trait_path.1) {
944 let full_trait_path = types.resolve_path(&trait_path.1, None);
945 let trait_obj = *types.crate_types.traits.get(&full_trait_path).unwrap();
948 let supertrait_resolver;
949 walk_supertraits!(trait_obj, Some(&types), (
951 if let Some(supertrait) = types.crate_types.traits.get(s) {
952 supertrait_name = s.to_string();
953 supertrait_resolver = get_module_type_resolver!(supertrait_name, types.crate_libs, types.crate_types);
954 gen_types.learn_associated_types(&supertrait, &supertrait_resolver);
959 // We learn the associated types maping from the original trait object.
960 // That's great, except that they are unresolved idents, so if we learn
961 // mappings from a trai defined in a different file, we may mis-resolve or
962 // fail to resolve the mapped types. Thus, we have to construct a new
963 // resolver for the module that the trait was defined in here first.
964 let mut trait_resolver = get_module_type_resolver!(full_trait_path, types.crate_libs, types.crate_types);
965 gen_types.learn_associated_types(trait_obj, &trait_resolver);
966 let mut impl_associated_types = HashMap::new();
967 for item in i.items.iter() {
969 syn::ImplItem::Type(t) => {
970 if let syn::Type::Path(p) = &t.ty {
971 if let Some(id) = single_ident_generic_path_to_ident(&p.path) {
972 impl_associated_types.insert(&t.ident, id);
980 let export = export_status(&trait_obj.attrs);
982 ExportStatus::Export|ExportStatus::NotImplementable => {},
983 ExportStatus::NoExport|ExportStatus::TestOnly => return,
986 // For cases where we have a concrete native object which implements a
987 // trait and need to return the C-mapped version of the trait, provide a
988 // From<> implementation which does all the work to ensure free is handled
989 // properly. This way we can call this method from deep in the
990 // type-conversion logic without actually knowing the concrete native type.
991 if !resolved_path.starts_with(types.module_path) {
992 if !first_seg_is_stdlib(resolved_path.split("::").next().unwrap()) {
993 w_uses.insert(format!("use crate::{}::native{} as native{};", resolved_path.rsplitn(2, "::").skip(1).next().unwrap(), ident, ident));
994 w_uses.insert(format!("use crate::{};", resolved_path));
995 w_uses.insert(format!("use crate::{}_free_void;", resolved_path));
997 w_uses.insert(format!("use {} as native{};", resolved_path, ident));
1000 writeln!(w, "impl From<native{}> for crate::{} {{", ident, full_trait_path).unwrap();
1001 writeln!(w, "\tfn from(obj: native{}) -> Self {{", ident).unwrap();
1002 if is_type_unconstructable(&resolved_path) {
1003 writeln!(w, "\t\tunreachable!();").unwrap();
1005 writeln!(w, "\t\tlet mut rust_obj = {} {{ inner: ObjOps::heap_alloc(obj), is_owned: true }};", ident).unwrap();
1006 writeln!(w, "\t\tlet mut ret = {}_as_{}(&rust_obj);", ident, trait_obj.ident).unwrap();
1007 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();
1008 writeln!(w, "\t\trust_obj.inner = core::ptr::null_mut();").unwrap();
1009 writeln!(w, "\t\tret.free = Some({}_free_void);", ident).unwrap();
1010 writeln!(w, "\t\tret").unwrap();
1012 writeln!(w, "\t}}\n}}").unwrap();
1013 if is_type_unconstructable(&resolved_path) {
1014 // We don't bother with Struct_as_Trait conversion for types which must
1015 // never be instantiated, so just return early.
1019 writeln!(w, "/// Constructs a new {} which calls the relevant methods on this_arg.", trait_obj.ident).unwrap();
1020 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();
1021 write!(w, "#[no_mangle]\npub extern \"C\" fn {}_as_{}(this_arg: &{}) -> crate::{} {{\n", ident, trait_obj.ident, ident, full_trait_path).unwrap();
1022 writeln!(w, "\tcrate::{} {{", full_trait_path).unwrap();
1023 writeln!(w, "\t\tthis_arg: unsafe {{ ObjOps::untweak_ptr((*this_arg).inner) as *mut c_void }},").unwrap();
1024 writeln!(w, "\t\tfree: None,").unwrap();
1026 macro_rules! write_meth {
1027 ($m: expr, $trait: expr, $indent: expr) => {
1028 let trait_method = $trait.items.iter().filter_map(|item| {
1029 if let syn::TraitItem::Method(t_m) = item { Some(t_m) } else { None }
1030 }).find(|trait_meth| trait_meth.sig.ident == $m.sig.ident).unwrap();
1031 match export_status(&trait_method.attrs) {
1032 ExportStatus::Export => {},
1033 ExportStatus::NoExport => {
1034 write!(w, "{}\t\t//XXX: Need to export {}\n", $indent, $m.sig.ident).unwrap();
1037 ExportStatus::TestOnly => continue,
1038 ExportStatus::NotImplementable => panic!("(C-not implementable) must only appear on traits"),
1041 let mut printed = false;
1042 if let syn::ReturnType::Type(_, rtype) = &$m.sig.output {
1043 if let syn::Type::Reference(r) = &**rtype {
1044 write!(w, "\n\t\t{}{}: ", $indent, $m.sig.ident).unwrap();
1045 types.write_empty_rust_val(Some(&gen_types), w, &*r.elem);
1046 writeln!(w, ".into(),\n{}\t\tset_{}: Some({}_{}_set_{}),", $indent, $m.sig.ident, ident, $trait.ident, $m.sig.ident).unwrap();
1051 write!(w, "{}\t\t{}: {}_{}_{},\n", $indent, $m.sig.ident, ident, $trait.ident, $m.sig.ident).unwrap();
1055 for item in trait_obj.items.iter() {
1057 syn::TraitItem::Method(m) => {
1058 write_meth!(m, trait_obj, "");
1063 let mut requires_clone = false;
1064 walk_supertraits!(trait_obj, Some(&types), (
1065 ("Clone", _, _) => {
1066 requires_clone = true;
1067 writeln!(w, "\t\tcloned: Some({}_{}_cloned),", trait_obj.ident, ident).unwrap();
1069 ("Sync", _, _) => {}, ("Send", _, _) => {},
1070 ("std::marker::Sync", _, _) => {}, ("std::marker::Send", _, _) => {},
1071 ("core::fmt::Debug", _, _) => {},
1073 if let Some(supertrait_obj) = types.crate_types.traits.get(s) {
1074 macro_rules! write_impl_fields {
1075 ($s: expr, $supertrait_obj: expr, $t: expr, $pfx: expr, $resolver: expr) => {
1076 writeln!(w, "{}\t{}: crate::{} {{", $pfx, $t, $s).unwrap();
1077 writeln!(w, "{}\t\tthis_arg: unsafe {{ ObjOps::untweak_ptr((*this_arg).inner) as *mut c_void }},", $pfx).unwrap();
1078 writeln!(w, "{}\t\tfree: None,", $pfx).unwrap();
1079 for item in $supertrait_obj.items.iter() {
1081 syn::TraitItem::Method(m) => {
1082 write_meth!(m, $supertrait_obj, $pfx);
1087 walk_supertraits!($supertrait_obj, Some(&$resolver), (
1088 ("Clone", _, _) => {
1089 writeln!(w, "{}\tcloned: Some({}_{}_cloned),", $pfx, $supertrait_obj.ident, ident).unwrap();
1095 write_impl_fields!(s, supertrait_obj, t, "\t", types);
1097 let resolver = get_module_type_resolver!(s, types.crate_libs, types.crate_types);
1098 walk_supertraits!(supertrait_obj, Some(&resolver), (
1100 if let Some(supertrait_obj) = types.crate_types.traits.get(s) {
1101 write_impl_fields!(s, supertrait_obj, t, "\t\t", resolver);
1102 write!(w, "\t\t\t}},\n").unwrap();
1106 write!(w, "\t\t}},\n").unwrap();
1108 write_trait_impl_field_assign(w, s, ident);
1112 writeln!(w, "\t}}\n}}\n").unwrap();
1114 macro_rules! impl_meth {
1115 ($m: expr, $trait_meth: expr, $trait_path: expr, $trait: expr, $indent: expr, $types: expr) => {
1116 let trait_method = $trait.items.iter().filter_map(|item| {
1117 if let syn::TraitItem::Method(t_m) = item { Some(t_m) } else { None }
1118 }).find(|trait_meth| trait_meth.sig.ident == $m.sig.ident).unwrap();
1119 match export_status(&trait_method.attrs) {
1120 ExportStatus::Export => {},
1121 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1122 ExportStatus::NotImplementable => panic!("(C-not implementable) must only appear on traits"),
1125 if let syn::ReturnType::Type(_, _) = &$m.sig.output {
1126 writeln!(w, "#[must_use]").unwrap();
1128 write!(w, "extern \"C\" fn {}_{}_{}(", ident, $trait.ident, $m.sig.ident).unwrap();
1129 let mut meth_gen_types = gen_types.push_ctx();
1130 assert!(meth_gen_types.learn_generics(&$m.sig.generics, $types));
1131 let mut uncallable_function = false;
1132 for inp in $m.sig.inputs.iter() {
1134 syn::FnArg::Typed(arg) => {
1135 if $types.skip_arg(&*arg.ty, Some(&meth_gen_types)) { continue; }
1136 let mut c_type = Vec::new();
1137 $types.write_c_type(&mut c_type, &*arg.ty, Some(&meth_gen_types), false);
1138 if is_type_unconstructable(&String::from_utf8(c_type).unwrap()) {
1139 uncallable_function = true;
1145 write_method_params(w, &$trait_meth.sig, "c_void", &mut trait_resolver, Some(&meth_gen_types), true, true);
1146 write!(w, " {{\n\t").unwrap();
1147 if uncallable_function {
1148 write!(w, "unreachable!();").unwrap();
1150 write_method_var_decl_body(w, &$trait_meth.sig, "", &mut trait_resolver, Some(&meth_gen_types), false);
1151 let mut takes_self = false;
1152 for inp in $m.sig.inputs.iter() {
1153 if let syn::FnArg::Receiver(_) = inp {
1158 let mut t_gen_args = String::new();
1159 for (idx, _) in $trait.generics.params.iter().enumerate() {
1160 if idx != 0 { t_gen_args += ", " };
1163 // rustc doesn't like <_> if the _ is actually a lifetime, so
1164 // if all the parameters are lifetimes just skip it.
1165 let mut nonlifetime_param = false;
1166 for param in $trait.generics.params.iter() {
1167 if let syn::GenericParam::Lifetime(_) = param {}
1168 else { nonlifetime_param = true; }
1170 if !nonlifetime_param { t_gen_args = String::new(); }
1172 write!(w, "<native{} as {}<{}>>::{}(unsafe {{ &mut *(this_arg as *mut native{}) }}, ", ident, $trait_path, t_gen_args, $m.sig.ident, ident).unwrap();
1174 write!(w, "<native{} as {}<{}>>::{}(", ident, $trait_path, t_gen_args, $m.sig.ident).unwrap();
1177 let mut real_type = "".to_string();
1178 match &$m.sig.output {
1179 syn::ReturnType::Type(_, rtype) => {
1180 if let Some(mut remaining_path) = first_seg_self(&*rtype) {
1181 if let Some(associated_seg) = get_single_remaining_path_seg(&mut remaining_path) {
1182 real_type = format!("{}", impl_associated_types.get(associated_seg).unwrap());
1188 write_method_call_params(w, &$trait_meth.sig, "", &mut trait_resolver, Some(&meth_gen_types), &real_type, false);
1190 write!(w, "\n}}\n").unwrap();
1191 if let syn::ReturnType::Type(_, rtype) = &$m.sig.output {
1192 if let syn::Type::Reference(r) = &**rtype {
1193 assert_eq!($m.sig.inputs.len(), 1); // Must only take self
1194 writeln!(w, "extern \"C\" fn {}_{}_set_{}(trait_self_arg: &{}) {{", ident, $trait.ident, $m.sig.ident, $trait.ident).unwrap();
1195 writeln!(w, "\t// This is a bit race-y in the general case, but for our specific use-cases today, we're safe").unwrap();
1196 writeln!(w, "\t// Specifically, we must ensure that the first time we're called it can never be in parallel").unwrap();
1197 write!(w, "\tif ").unwrap();
1198 $types.write_empty_rust_val_check(Some(&meth_gen_types), w, &*r.elem, &format!("unsafe {{ &*trait_self_arg.{}.get() }}", $m.sig.ident));
1199 writeln!(w, " {{").unwrap();
1200 writeln!(w, "\t\t*unsafe {{ &mut *(&*(trait_self_arg as *const {})).{}.get() }} = {}_{}_{}(trait_self_arg.this_arg).into();", $trait.ident, $m.sig.ident, ident, $trait.ident, $m.sig.ident).unwrap();
1201 writeln!(w, "\t}}").unwrap();
1202 writeln!(w, "}}").unwrap();
1208 'impl_item_loop: for trait_item in trait_obj.items.iter() {
1210 syn::TraitItem::Method(meth) => {
1211 for item in i.items.iter() {
1213 syn::ImplItem::Method(m) => {
1214 if meth.sig.ident == m.sig.ident {
1215 impl_meth!(m, meth, full_trait_path, trait_obj, "", types);
1216 continue 'impl_item_loop;
1219 syn::ImplItem::Type(_) => {},
1220 _ => unimplemented!(),
1223 assert!(meth.default.is_some());
1224 let old_gen_types = gen_types;
1225 gen_types = GenericTypes::new(Some(resolved_path.clone()));
1226 impl_meth!(meth, meth, full_trait_path, trait_obj, "", &mut trait_resolver);
1227 gen_types = old_gen_types;
1233 writeln!(w, "extern \"C\" fn {}_{}_cloned(new_obj: &mut crate::{}) {{", trait_obj.ident, ident, full_trait_path).unwrap();
1234 writeln!(w, "\tnew_obj.this_arg = {}_clone_void(new_obj.this_arg);", ident).unwrap();
1235 writeln!(w, "\tnew_obj.free = Some({}_free_void);", ident).unwrap();
1236 walk_supertraits!(trait_obj, Some(&types), (
1238 if types.crate_types.traits.get(s).is_some() {
1239 assert!(!types.is_clonable(s)); // We don't currently support cloning with a clonable supertrait
1240 writeln!(w, "\tnew_obj.{}.this_arg = new_obj.this_arg;", t).unwrap();
1241 writeln!(w, "\tnew_obj.{}.free = None;", t).unwrap();
1245 writeln!(w, "}}").unwrap();
1247 write!(w, "\n").unwrap();
1250 if is_type_unconstructable(&resolved_path) {
1251 // Don't bother exposing trait implementations for objects which cannot be
1255 if path_matches_nongeneric(&trait_path.1, &["From"]) {
1256 } else if path_matches_nongeneric(&trait_path.1, &["Default"]) {
1257 writeln!(w, "/// Creates a \"default\" {}. See struct and individual field documentaiton for details on which values are used.", ident).unwrap();
1258 write!(w, "#[must_use]\n#[no_mangle]\npub extern \"C\" fn {}_default() -> {} {{\n", ident, ident).unwrap();
1259 write!(w, "\t{} {{ inner: ObjOps::heap_alloc(Default::default()), is_owned: true }}\n", ident).unwrap();
1260 write!(w, "}}\n").unwrap();
1261 } else if path_matches_nongeneric(&trait_path.1, &["core", "cmp", "PartialEq"]) {
1262 } else if path_matches_nongeneric(&trait_path.1, &["core", "cmp", "Eq"]) {
1263 writeln!(w, "/// Checks if two {}s contain equal inner contents.", ident).unwrap();
1264 writeln!(w, "/// This ignores pointers and is_owned flags and looks at the values in fields.").unwrap();
1265 if types.c_type_has_inner_from_path(&resolved_path) {
1266 writeln!(w, "/// Two objects with NULL inner values will be considered \"equal\" here.").unwrap();
1268 write!(w, "#[no_mangle]\npub extern \"C\" fn {}_eq(a: &{}, b: &{}) -> bool {{\n", ident, ident, ident).unwrap();
1269 if types.c_type_has_inner_from_path(&resolved_path) {
1270 write!(w, "\tif a.inner == b.inner {{ return true; }}\n").unwrap();
1271 write!(w, "\tif a.inner.is_null() || b.inner.is_null() {{ return false; }}\n").unwrap();
1275 let ref_type: syn::Type = syn::parse_quote!(&#path);
1276 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");
1278 write!(w, "\tif ").unwrap();
1279 types.write_from_c_conversion_prefix(w, &ref_type, Some(&gen_types));
1280 write!(w, "a").unwrap();
1281 types.write_from_c_conversion_suffix(w, &ref_type, Some(&gen_types));
1282 write!(w, " == ").unwrap();
1283 types.write_from_c_conversion_prefix(w, &ref_type, Some(&gen_types));
1284 write!(w, "b").unwrap();
1285 types.write_from_c_conversion_suffix(w, &ref_type, Some(&gen_types));
1287 writeln!(w, " {{ true }} else {{ false }}\n}}").unwrap();
1288 } else if path_matches_nongeneric(&trait_path.1, &["core", "hash", "Hash"]) {
1289 writeln!(w, "/// Generates a non-cryptographic 64-bit hash of the {}.", ident).unwrap();
1290 write!(w, "#[no_mangle]\npub extern \"C\" fn {}_hash(o: &{}) -> u64 {{\n", ident, ident).unwrap();
1291 if types.c_type_has_inner_from_path(&resolved_path) {
1292 write!(w, "\tif o.inner.is_null() {{ return 0; }}\n").unwrap();
1296 let ref_type: syn::Type = syn::parse_quote!(&#path);
1297 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");
1299 writeln!(w, "\t// Note that we'd love to use alloc::collections::hash_map::DefaultHasher but it's not in core").unwrap();
1300 writeln!(w, "\t#[allow(deprecated)]").unwrap();
1301 writeln!(w, "\tlet mut hasher = core::hash::SipHasher::new();").unwrap();
1302 write!(w, "\tcore::hash::Hash::hash(").unwrap();
1303 types.write_from_c_conversion_prefix(w, &ref_type, Some(&gen_types));
1304 write!(w, "o").unwrap();
1305 types.write_from_c_conversion_suffix(w, &ref_type, Some(&gen_types));
1306 writeln!(w, ", &mut hasher);").unwrap();
1307 writeln!(w, "\tcore::hash::Hasher::finish(&hasher)\n}}").unwrap();
1308 } else if (path_matches_nongeneric(&trait_path.1, &["core", "clone", "Clone"]) || path_matches_nongeneric(&trait_path.1, &["Clone"])) &&
1309 types.c_type_has_inner_from_path(&resolved_path) {
1310 writeln!(w, "impl Clone for {} {{", ident).unwrap();
1311 writeln!(w, "\tfn clone(&self) -> Self {{").unwrap();
1312 writeln!(w, "\t\tSelf {{").unwrap();
1313 writeln!(w, "\t\t\tinner: if <*mut native{}>::is_null(self.inner) {{ core::ptr::null_mut() }} else {{", ident).unwrap();
1314 writeln!(w, "\t\t\t\tObjOps::heap_alloc(unsafe {{ &*ObjOps::untweak_ptr(self.inner) }}.clone()) }},").unwrap();
1315 writeln!(w, "\t\t\tis_owned: true,").unwrap();
1316 writeln!(w, "\t\t}}\n\t}}\n}}").unwrap();
1317 writeln!(w, "#[allow(unused)]").unwrap();
1318 writeln!(w, "/// Used only if an object of this type is returned as a trait impl by a method").unwrap();
1319 writeln!(w, "pub(crate) extern \"C\" fn {}_clone_void(this_ptr: *const c_void) -> *mut c_void {{", ident).unwrap();
1320 writeln!(w, "\tBox::into_raw(Box::new(unsafe {{ (*(this_ptr as *mut native{})).clone() }})) as *mut c_void", ident).unwrap();
1321 writeln!(w, "}}").unwrap();
1322 writeln!(w, "#[no_mangle]").unwrap();
1323 writeln!(w, "/// Creates a copy of the {}", ident).unwrap();
1324 writeln!(w, "pub extern \"C\" fn {}_clone(orig: &{}) -> {} {{", ident, ident, ident).unwrap();
1325 writeln!(w, "\torig.clone()").unwrap();
1326 writeln!(w, "}}").unwrap();
1327 } else if path_matches_nongeneric(&trait_path.1, &["FromStr"]) {
1328 let mut err_opt = None;
1329 for item in i.items.iter() {
1331 syn::ImplItem::Type(ty) if format!("{}", ty.ident) == "Err" => {
1332 err_opt = Some(&ty.ty);
1337 let err_ty = err_opt.unwrap();
1338 if let Some(container) = types.get_c_mangled_container_type(vec![&*i.self_ty, &err_ty], Some(&gen_types), "Result") {
1339 writeln!(w, "#[no_mangle]").unwrap();
1340 writeln!(w, "/// Read a {} object from a string", ident).unwrap();
1341 writeln!(w, "pub extern \"C\" fn {}_from_str(s: crate::c_types::Str) -> {} {{", ident, container).unwrap();
1342 writeln!(w, "\tmatch {}::from_str(s.into_str()) {{", resolved_path).unwrap();
1344 writeln!(w, "\t\tOk(r) => {{").unwrap();
1345 let new_var = types.write_to_c_conversion_new_var(w, &format_ident!("r"), &*i.self_ty, Some(&gen_types), false);
1346 write!(w, "\t\t\tcrate::c_types::CResultTempl::ok(\n\t\t\t\t").unwrap();
1347 types.write_to_c_conversion_inline_prefix(w, &*i.self_ty, Some(&gen_types), false);
1348 write!(w, "{}r", if new_var { "local_" } else { "" }).unwrap();
1349 types.write_to_c_conversion_inline_suffix(w, &*i.self_ty, Some(&gen_types), false);
1350 writeln!(w, "\n\t\t\t)\n\t\t}},").unwrap();
1352 writeln!(w, "\t\tErr(e) => {{").unwrap();
1353 let new_var = types.write_to_c_conversion_new_var(w, &format_ident!("e"), &err_ty, Some(&gen_types), false);
1354 write!(w, "\t\t\tcrate::c_types::CResultTempl::err(\n\t\t\t\t").unwrap();
1355 types.write_to_c_conversion_inline_prefix(w, &err_ty, Some(&gen_types), false);
1356 write!(w, "{}e", if new_var { "local_" } else { "" }).unwrap();
1357 types.write_to_c_conversion_inline_suffix(w, &err_ty, Some(&gen_types), false);
1358 writeln!(w, "\n\t\t\t)\n\t\t}},").unwrap();
1360 writeln!(w, "\t}}.into()\n}}").unwrap();
1362 } else if path_matches_nongeneric(&trait_path.1, &["Display"]) {
1363 writeln!(w, "#[no_mangle]").unwrap();
1364 writeln!(w, "/// Get the string representation of a {} object", ident).unwrap();
1365 writeln!(w, "pub extern \"C\" fn {}_to_str(o: &crate::{}) -> Str {{", ident, resolved_path).unwrap();
1367 let self_ty = &i.self_ty;
1368 let ref_type: syn::Type = syn::parse_quote!(&#self_ty);
1369 let new_var = types.write_from_c_conversion_new_var(w, &format_ident!("o"), &ref_type, Some(&gen_types));
1370 write!(w, "\talloc::format!(\"{{}}\", ").unwrap();
1371 types.write_from_c_conversion_prefix(w, &ref_type, Some(&gen_types));
1372 write!(w, "{}o", if new_var { "local_" } else { "" }).unwrap();
1373 types.write_from_c_conversion_suffix(w, &ref_type, Some(&gen_types));
1374 writeln!(w, ").into()").unwrap();
1376 writeln!(w, "}}").unwrap();
1378 //XXX: implement for other things like ToString
1379 // If we have no generics, try a manual implementation:
1380 maybe_convert_trait_impl(w, &trait_path.1, &*i.self_ty, types, &gen_types);
1383 let is_opaque = types.crate_types.opaques.contains_key(&resolved_path);
1384 let is_mirrored_enum = types.crate_types.mirrored_enums.contains_key(&resolved_path);
1385 for item in i.items.iter() {
1387 syn::ImplItem::Method(m) => {
1388 if let syn::Visibility::Public(_) = m.vis {
1389 match export_status(&m.attrs) {
1390 ExportStatus::Export => {},
1391 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1392 ExportStatus::NotImplementable => panic!("(C-not implementable) must only appear on traits"),
1394 if m.sig.asyncness.is_some() { continue; }
1395 let mut meth_gen_types = gen_types.push_ctx();
1396 assert!(meth_gen_types.learn_generics(&m.sig.generics, types));
1397 if m.defaultness.is_some() { unimplemented!(); }
1398 writeln_fn_docs(w, &m.attrs, "", types, Some(&meth_gen_types), m.sig.inputs.iter(), &m.sig.output);
1399 if let syn::ReturnType::Type(_, _) = &m.sig.output {
1400 writeln!(w, "#[must_use]").unwrap();
1402 write!(w, "#[no_mangle]\npub extern \"C\" fn {}_{}(", ident, m.sig.ident).unwrap();
1403 let ret_type = format!("crate::{}", resolved_path);
1404 write_method_params(w, &m.sig, &ret_type, types, Some(&meth_gen_types), false, true);
1405 write!(w, " {{\n\t").unwrap();
1406 write_method_var_decl_body(w, &m.sig, "", types, Some(&meth_gen_types), false);
1407 let mut takes_self = false;
1408 let mut takes_mut_self = false;
1409 let mut takes_owned_self = false;
1410 for inp in m.sig.inputs.iter() {
1411 if let syn::FnArg::Receiver(r) = inp {
1413 if r.mutability.is_some() { takes_mut_self = true; }
1414 if r.reference.is_none() { takes_owned_self = true; }
1417 if !takes_mut_self && !takes_self {
1418 write!(w, "{}::{}(", resolved_path, m.sig.ident).unwrap();
1420 if is_mirrored_enum {
1421 write!(w, "this_arg.to_native().{}(", m.sig.ident).unwrap();
1422 } else if is_opaque {
1423 if takes_owned_self {
1424 write!(w, "(*unsafe {{ Box::from_raw(this_arg.take_inner()) }}).{}(", m.sig.ident).unwrap();
1425 } else if takes_mut_self {
1426 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();
1428 write!(w, "unsafe {{ &*ObjOps::untweak_ptr(this_arg.inner) }}.{}(", m.sig.ident).unwrap();
1434 write_method_call_params(w, &m.sig, "", types, Some(&meth_gen_types), &ret_type, false);
1435 writeln!(w, "\n}}\n").unwrap();
1442 } else if let Some(resolved_path) = types.maybe_resolve_ident(&ident) {
1443 create_alias_for_impl(resolved_path, i, types, move |aliased_impl, types| writeln_impl(w, w_uses, &aliased_impl, types));
1445 eprintln!("Not implementing anything for {} due to no-resolve (probably the type isn't pub)", ident);
1451 fn create_alias_for_impl<F: FnMut(syn::ItemImpl, &mut TypeResolver)>(resolved_path: String, i: &syn::ItemImpl, types: &mut TypeResolver, mut callback: F) {
1452 if let Some(aliases) = types.crate_types.reverse_alias_map.get(&resolved_path).cloned() {
1453 let mut gen_types = Some(GenericTypes::new(Some(resolved_path.clone())));
1454 if !gen_types.as_mut().unwrap().learn_generics(&i.generics, types) {
1457 let alias_module = rsplit_once(&resolved_path, "::").unwrap().0;
1459 'alias_impls: for (alias_resolved, arguments) in aliases {
1460 let mut new_ty_generics = Vec::new();
1461 let mut new_ty_bounds = Vec::new();
1462 let mut need_generics = false;
1464 let alias_resolver_override;
1465 let alias_resolver = if alias_module != types.module_path {
1466 alias_resolver_override = ImportResolver::new(types.types.crate_name, &types.crate_types.lib_ast,
1467 alias_module, &types.crate_types.lib_ast.modules.get(alias_module).unwrap().items);
1468 &alias_resolver_override
1469 } else { &types.types };
1470 let mut where_clause = syn::WhereClause { where_token: syn::Token),
1471 predicates: syn::punctuated::Punctuated::new()
1473 for (idx, gen) in i.generics.params.iter().enumerate() {
1475 syn::GenericParam::Type(type_param) => {
1476 'bounds_check: for bound in type_param.bounds.iter() {
1477 if let syn::TypeParamBound::Trait(trait_bound) = bound {
1478 if let syn::PathArguments::AngleBracketed(ref t) = &arguments {
1479 assert!(idx < t.args.len());
1480 if let syn::GenericArgument::Type(syn::Type::Path(p)) = &t.args[idx] {
1481 let generic_bound = types.maybe_resolve_path(&trait_bound.path, None)
1482 .unwrap_or_else(|| format!("{}::{}", types.module_path, single_ident_generic_path_to_ident(&trait_bound.path).unwrap()));
1484 if let Some(generic_arg) = alias_resolver.maybe_resolve_path(&p.path, None) {
1485 new_ty_generics.push((type_param.ident.clone(), syn::Type::Path(p.clone())));
1486 if let Some(traits_impld) = types.crate_types.trait_impls.get(&generic_arg) {
1487 for trait_impld in traits_impld {
1488 if *trait_impld == generic_bound { continue 'bounds_check; }
1490 eprintln!("struct {}'s generic arg {} didn't match bound {}", alias_resolved, generic_arg, generic_bound);
1491 continue 'alias_impls;
1493 eprintln!("struct {}'s generic arg {} didn't match bound {}", alias_resolved, generic_arg, generic_bound);
1494 continue 'alias_impls;
1496 } else if gen_types.is_some() {
1497 let resp = types.maybe_resolve_path(&p.path, gen_types.as_ref());
1498 if generic_bound == "core::ops::Deref" && resp.is_some() {
1499 new_ty_bounds.push((type_param.ident.clone(),
1500 string_path_to_syn_path("core::ops::Deref")));
1501 let mut bounds = syn::punctuated::Punctuated::new();
1502 bounds.push(syn::TypeParamBound::Trait(syn::TraitBound {
1504 modifier: syn::TraitBoundModifier::None,
1506 path: string_path_to_syn_path(&types.resolve_path(&p.path, gen_types.as_ref())),
1508 let mut path = string_path_to_syn_path(&format!("{}::Target", type_param.ident));
1509 path.leading_colon = None;
1510 where_clause.predicates.push(syn::WherePredicate::Type(syn::PredicateType {
1512 bounded_ty: syn::Type::Path(syn::TypePath { qself: None, path }),
1513 colon_token: syn::Token),
1517 new_ty_generics.push((type_param.ident.clone(),
1518 gen_types.as_ref().resolve_type(&syn::Type::Path(p.clone())).clone()));
1520 need_generics = true;
1524 } else { unimplemented!(); }
1525 } else { unimplemented!(); }
1526 } else { unimplemented!(); }
1529 syn::GenericParam::Lifetime(_) => {},
1530 syn::GenericParam::Const(_) => unimplemented!(),
1533 let mut params = syn::punctuated::Punctuated::new();
1534 let alias = string_path_to_syn_path(&alias_resolved);
1537 let alias_generics = types.crate_types.opaques.get(&alias_resolved).unwrap().1;
1539 // If we need generics on the alias, create impl generic bounds...
1540 assert_eq!(new_ty_generics.len() + new_ty_bounds.len(), i.generics.params.len());
1541 let mut args = syn::punctuated::Punctuated::new();
1542 for (ident, param) in new_ty_generics.drain(..) {
1543 // TODO: We blindly assume that generics in the type alias and
1544 // the aliased type have the same names, which we really shouldn't.
1545 if alias_generics.params.iter().any(|generic|
1546 if let syn::GenericParam::Type(t) = generic { t.ident == ident } else { false })
1548 args.push(parse_quote!(#ident));
1550 params.push(syn::GenericParam::Type(syn::TypeParam {
1554 bounds: syn::punctuated::Punctuated::new(),
1555 eq_token: Some(syn::token::Eq(Span::call_site())),
1556 default: Some(param),
1559 for (ident, param) in new_ty_bounds.drain(..) {
1560 // TODO: We blindly assume that generics in the type alias and
1561 // the aliased type have the same names, which we really shouldn't.
1562 if alias_generics.params.iter().any(|generic|
1563 if let syn::GenericParam::Type(t) = generic { t.ident == ident } else { false })
1565 args.push(parse_quote!(#ident));
1567 params.push(syn::GenericParam::Type(syn::TypeParam {
1570 colon_token: Some(syn::token::Colon(Span::call_site())),
1571 bounds: syn::punctuated::Punctuated::from_iter(
1572 Some(syn::TypeParamBound::Trait(syn::TraitBound {
1573 path: param, paren_token: None, lifetimes: None,
1574 modifier: syn::TraitBoundModifier::None,
1581 // ... and swap the last segment of the impl self_ty to use the generic bounds.
1582 let mut res = alias.clone();
1583 res.segments.last_mut().unwrap().arguments = syn::PathArguments::AngleBracketed(syn::AngleBracketedGenericArguments {
1585 lt_token: syn::token::Lt(Span::call_site()),
1587 gt_token: syn::token::Gt(Span::call_site()),
1590 } else { alias.clone() };
1591 callback(syn::ItemImpl {
1592 attrs: i.attrs.clone(),
1593 brace_token: syn::token::Brace(Span::call_site()),
1595 generics: syn::Generics {
1599 where_clause: Some(where_clause),
1601 impl_token: syn::Token),
1602 items: i.items.clone(),
1603 self_ty: Box::new(syn::Type::Path(syn::TypePath { qself: None, path: real_aliased })),
1604 trait_: i.trait_.clone(),
1609 eprintln!("Not implementing anything for {} due to it being marked not exported", resolved_path);
1613 /// Replaces upper case charachters with underscore followed by lower case except the first
1614 /// charachter and repeated upper case characthers (which are only made lower case).
1615 fn camel_to_snake_case(camel: &str) -> String {
1616 let mut res = "".to_string();
1617 let mut last_upper = -1;
1618 for (idx, c) in camel.chars().enumerate() {
1619 if c.is_uppercase() {
1620 if last_upper != idx as isize - 1 { res.push('_'); }
1621 res.push(c.to_lowercase().next().unwrap());
1622 last_upper = idx as isize;
1631 /// Print a mapping of an enum. If all of the enum's fields are C-mapped in some form (or the enum
1632 /// is unitary), we generate an equivalent enum with all types replaced with their C mapped
1633 /// versions followed by conversion functions which map between the Rust version and the C mapped
1635 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) {
1636 match export_status(&e.attrs) {
1637 ExportStatus::Export => {},
1638 ExportStatus::NoExport|ExportStatus::TestOnly => return,
1639 ExportStatus::NotImplementable => panic!("(C-not implementable) must only appear on traits"),
1642 if is_enum_opaque(e) {
1643 eprintln!("Skipping enum {} as it contains non-unit fields", e.ident);
1644 writeln_opaque(w, &e.ident, &format!("{}", e.ident), &e.generics, &e.attrs, types, extra_headers, cpp_headers);
1647 writeln_docs(w, &e.attrs, "");
1649 let mut gen_types = GenericTypes::new(None);
1650 assert!(gen_types.learn_generics(&e.generics, types));
1652 let mut needs_free = false;
1653 let mut constr = Vec::new();
1654 let mut is_clonable = true;
1656 for var in e.variants.iter() {
1657 if let syn::Fields::Named(fields) = &var.fields {
1659 for field in fields.named.iter() {
1660 if export_status(&field.attrs) == ExportStatus::TestOnly { continue; }
1662 let mut ty_checks = Vec::new();
1663 types.write_c_type(&mut ty_checks, &field.ty, Some(&gen_types), false);
1664 if !types.is_clonable(&String::from_utf8(ty_checks).unwrap()) {
1665 is_clonable = false;
1668 } else if let syn::Fields::Unnamed(fields) = &var.fields {
1669 for field in fields.unnamed.iter() {
1670 let mut ty_checks = Vec::new();
1671 types.write_c_type(&mut ty_checks, &field.ty, Some(&gen_types), false);
1672 let ty = String::from_utf8(ty_checks).unwrap();
1673 if ty != "" && !types.is_clonable(&ty) {
1674 is_clonable = false;
1681 writeln!(w, "#[derive(Clone)]").unwrap();
1682 types.crate_types.set_clonable(format!("{}::{}", types.module_path, e.ident));
1684 writeln!(w, "#[must_use]\n#[repr(C)]\npub enum {} {{", e.ident).unwrap();
1685 for var in e.variants.iter() {
1686 assert_eq!(export_status(&var.attrs), ExportStatus::Export); // We can't partially-export a mirrored enum
1687 writeln_docs(w, &var.attrs, "\t");
1688 write!(w, "\t{}", var.ident).unwrap();
1689 writeln!(&mut constr, "#[no_mangle]\n/// Utility method to constructs a new {}-variant {}", var.ident, e.ident).unwrap();
1690 let constr_name = camel_to_snake_case(&format!("{}", var.ident));
1691 write!(&mut constr, "pub extern \"C\" fn {}_{}(", e.ident, constr_name).unwrap();
1692 let mut empty_tuple_variant = false;
1693 if let syn::Fields::Named(fields) = &var.fields {
1695 writeln!(w, " {{").unwrap();
1696 for (idx, field) in fields.named.iter().enumerate() {
1697 if export_status(&field.attrs) == ExportStatus::TestOnly { continue; }
1698 writeln_field_docs(w, &field.attrs, "\t\t", types, Some(&gen_types), &field.ty);
1699 write!(w, "\t\t{}: ", field.ident.as_ref().unwrap()).unwrap();
1700 write!(&mut constr, "{}{}: ", if idx != 0 { ", " } else { "" }, field.ident.as_ref().unwrap()).unwrap();
1701 types.write_c_type(w, &field.ty, Some(&gen_types), true);
1702 types.write_c_type(&mut constr, &field.ty, Some(&gen_types), true);
1703 writeln!(w, ",").unwrap();
1705 write!(w, "\t}}").unwrap();
1706 } else if let syn::Fields::Unnamed(fields) = &var.fields {
1707 if fields.unnamed.len() == 1 {
1708 let mut empty_check = Vec::new();
1709 types.write_c_type(&mut empty_check, &fields.unnamed[0].ty, Some(&gen_types), true);
1710 if empty_check.is_empty() {
1711 empty_tuple_variant = true;
1714 if !empty_tuple_variant {
1716 writeln!(w, "(").unwrap();
1717 for (idx, field) in fields.unnamed.iter().enumerate() {
1718 if export_status(&field.attrs) == ExportStatus::TestOnly { continue; }
1719 writeln_field_docs(w, &field.attrs, "\t\t", types, Some(&gen_types), &field.ty);
1720 write!(w, "\t\t").unwrap();
1721 types.write_c_type(w, &field.ty, Some(&gen_types), true);
1723 write!(&mut constr, "{}: ", ('a' as u8 + idx as u8) as char).unwrap();
1724 types.write_c_type(&mut constr, &field.ty, Some(&gen_types), false);
1725 if idx != fields.unnamed.len() - 1 {
1726 writeln!(w, ",").unwrap();
1727 write!(&mut constr, ",").unwrap();
1730 write!(w, ")").unwrap();
1733 write!(&mut constr, ") -> {} {{\n\t{}::{}", e.ident, e.ident, var.ident).unwrap();
1734 if let syn::Fields::Named(fields) = &var.fields {
1735 writeln!(&mut constr, " {{").unwrap();
1736 for field in fields.named.iter() {
1737 writeln!(&mut constr, "\t\t{},", field.ident.as_ref().unwrap()).unwrap();
1739 writeln!(&mut constr, "\t}}").unwrap();
1740 } else if let syn::Fields::Unnamed(fields) = &var.fields {
1741 if !empty_tuple_variant {
1742 write!(&mut constr, "(").unwrap();
1743 for (idx, field) in fields.unnamed.iter().enumerate() {
1744 let mut ref_c_ty = Vec::new();
1745 let mut nonref_c_ty = Vec::new();
1746 types.write_c_type(&mut ref_c_ty, &field.ty, Some(&gen_types), false);
1747 types.write_c_type(&mut nonref_c_ty, &field.ty, Some(&gen_types), true);
1749 if ref_c_ty != nonref_c_ty {
1750 // We blindly assume references in field types are always opaque types, and
1751 // print out an opaque reference -> owned reference conversion here.
1752 write!(&mut constr, "{} {{ inner: {}.inner, is_owned: false }}, ", String::from_utf8(nonref_c_ty).unwrap(), ('a' as u8 + idx as u8) as char).unwrap();
1754 write!(&mut constr, "{}, ", ('a' as u8 + idx as u8) as char).unwrap();
1757 writeln!(&mut constr, ")").unwrap();
1759 writeln!(&mut constr, "").unwrap();
1762 writeln!(&mut constr, "}}").unwrap();
1763 writeln!(w, ",").unwrap();
1765 writeln!(w, "}}\nuse {}::{} as {}Import;", types.module_path, e.ident, e.ident).unwrap();
1766 write!(w, "pub(crate) type native{} = {}Import", e.ident, e.ident).unwrap();
1767 maybe_write_generics(w, &e.generics, &syn::PathArguments::None, &types, true);
1768 writeln!(w, ";\n\nimpl {} {{", e.ident).unwrap();
1770 macro_rules! write_conv {
1771 ($fn_sig: expr, $to_c: expr, $ref: expr) => {
1772 writeln!(w, "\t#[allow(unused)]\n\tpub(crate) fn {} {{\n\t\tmatch {} {{", $fn_sig, if $to_c { "native" } else { "self" }).unwrap();
1773 for var in e.variants.iter() {
1774 write!(w, "\t\t\t{}{}::{} ", if $to_c { "native" } else { "" }, e.ident, var.ident).unwrap();
1775 let mut empty_tuple_variant = false;
1776 if let syn::Fields::Named(fields) = &var.fields {
1777 write!(w, "{{").unwrap();
1778 for field in fields.named.iter() {
1779 if export_status(&field.attrs) == ExportStatus::TestOnly { continue; }
1780 write!(w, "{}{}, ", if $ref { "ref " } else { "mut " }, field.ident.as_ref().unwrap()).unwrap();
1782 write!(w, "}} ").unwrap();
1783 } else if let syn::Fields::Unnamed(fields) = &var.fields {
1784 if fields.unnamed.len() == 1 {
1785 let mut empty_check = Vec::new();
1786 types.write_c_type(&mut empty_check, &fields.unnamed[0].ty, Some(&gen_types), true);
1787 if empty_check.is_empty() {
1788 empty_tuple_variant = true;
1791 if !empty_tuple_variant || $to_c {
1792 write!(w, "(").unwrap();
1793 for (idx, field) in fields.unnamed.iter().enumerate() {
1794 if export_status(&field.attrs) == ExportStatus::TestOnly { continue; }
1795 write!(w, "{}{}, ", if $ref { "ref " } else { "mut " }, ('a' as u8 + idx as u8) as char).unwrap();
1797 write!(w, ") ").unwrap();
1800 write!(w, "=>").unwrap();
1802 macro_rules! handle_field_a {
1803 ($field: expr, $field_ident: expr) => { {
1804 if export_status(&$field.attrs) == ExportStatus::TestOnly { continue; }
1805 let mut sink = ::std::io::sink();
1806 let mut out: &mut dyn std::io::Write = if $ref { &mut sink } else { w };
1807 let new_var = if $to_c {
1808 types.write_to_c_conversion_new_var(&mut out, $field_ident, &$field.ty, Some(&gen_types), true)
1810 types.write_from_c_conversion_new_var(&mut out, $field_ident, &$field.ty, Some(&gen_types))
1812 if $ref || new_var {
1814 write!(w, "let mut {}_nonref = Clone::clone({});\n\t\t\t\t", $field_ident, $field_ident).unwrap();
1816 let nonref_ident = format_ident!("{}_nonref", $field_ident);
1818 types.write_to_c_conversion_new_var(w, &nonref_ident, &$field.ty, Some(&gen_types), true);
1820 types.write_from_c_conversion_new_var(w, &nonref_ident, &$field.ty, Some(&gen_types));
1822 write!(w, "\n\t\t\t\t").unwrap();
1825 write!(w, "\n\t\t\t\t").unwrap();
1830 if let syn::Fields::Named(fields) = &var.fields {
1831 write!(w, " {{\n\t\t\t\t").unwrap();
1832 for field in fields.named.iter() {
1833 handle_field_a!(field, field.ident.as_ref().unwrap());
1835 } else if let syn::Fields::Unnamed(fields) = &var.fields {
1836 write!(w, " {{\n\t\t\t\t").unwrap();
1837 for (idx, field) in fields.unnamed.iter().enumerate() {
1838 if !empty_tuple_variant {
1839 handle_field_a!(field, &format_ident!("{}", ('a' as u8 + idx as u8) as char));
1842 } else { write!(w, " ").unwrap(); }
1844 write!(w, "{}{}::{}", if $to_c { "" } else { "native" }, e.ident, var.ident).unwrap();
1846 macro_rules! handle_field_b {
1847 ($field: expr, $field_ident: expr) => { {
1848 if export_status(&$field.attrs) == ExportStatus::TestOnly { continue; }
1850 types.write_to_c_conversion_inline_prefix(w, &$field.ty, Some(&gen_types), true);
1852 types.write_from_c_conversion_prefix(w, &$field.ty, Some(&gen_types));
1854 write!(w, "{}{}", $field_ident,
1855 if $ref { "_nonref" } else { "" }).unwrap();
1857 types.write_to_c_conversion_inline_suffix(w, &$field.ty, Some(&gen_types), true);
1859 types.write_from_c_conversion_suffix(w, &$field.ty, Some(&gen_types));
1861 write!(w, ",").unwrap();
1865 if let syn::Fields::Named(fields) = &var.fields {
1866 write!(w, " {{").unwrap();
1867 for field in fields.named.iter() {
1868 if export_status(&field.attrs) == ExportStatus::TestOnly { continue; }
1869 write!(w, "\n\t\t\t\t\t{}: ", field.ident.as_ref().unwrap()).unwrap();
1870 handle_field_b!(field, field.ident.as_ref().unwrap());
1872 writeln!(w, "\n\t\t\t\t}}").unwrap();
1873 write!(w, "\t\t\t}}").unwrap();
1874 } else if let syn::Fields::Unnamed(fields) = &var.fields {
1875 if !empty_tuple_variant || !$to_c {
1876 write!(w, " (").unwrap();
1877 for (idx, field) in fields.unnamed.iter().enumerate() {
1878 write!(w, "\n\t\t\t\t\t").unwrap();
1879 handle_field_b!(field, &format_ident!("{}", ('a' as u8 + idx as u8) as char));
1881 writeln!(w, "\n\t\t\t\t)").unwrap();
1883 write!(w, "\t\t\t}}").unwrap();
1885 writeln!(w, ",").unwrap();
1887 writeln!(w, "\t\t}}\n\t}}").unwrap();
1892 write_conv!(format!("to_native(&self) -> native{}", e.ident), false, true);
1894 write_conv!(format!("into_native(self) -> native{}", e.ident), false, false);
1896 write_conv!(format!("from_native(native: &native{}) -> Self", e.ident), true, true);
1898 write_conv!(format!("native_into(native: native{}) -> Self", e.ident), true, false);
1899 writeln!(w, "}}").unwrap();
1902 writeln!(w, "/// Frees any resources used by the {}", e.ident).unwrap();
1903 writeln!(w, "#[no_mangle]\npub extern \"C\" fn {}_free(this_ptr: {}) {{ }}", e.ident, e.ident).unwrap();
1906 writeln!(w, "/// Creates a copy of the {}", e.ident).unwrap();
1907 writeln!(w, "#[no_mangle]").unwrap();
1908 writeln!(w, "pub extern \"C\" fn {}_clone(orig: &{}) -> {} {{", e.ident, e.ident, e.ident).unwrap();
1909 writeln!(w, "\torig.clone()").unwrap();
1910 writeln!(w, "}}").unwrap();
1912 w.write_all(&constr).unwrap();
1913 write_cpp_wrapper(cpp_headers, &format!("{}", e.ident), needs_free, None);
1916 fn writeln_fn<'a, 'b, W: std::io::Write>(w: &mut W, f: &'a syn::ItemFn, types: &mut TypeResolver<'b, 'a>) {
1917 match export_status(&f.attrs) {
1918 ExportStatus::Export => {},
1919 ExportStatus::NoExport|ExportStatus::TestOnly => return,
1920 ExportStatus::NotImplementable => panic!("(C-not implementable) must only appear on traits"),
1922 let mut gen_types = GenericTypes::new(None);
1923 if !gen_types.learn_generics(&f.sig.generics, types) { return; }
1925 writeln_fn_docs(w, &f.attrs, "", types, Some(&gen_types), f.sig.inputs.iter(), &f.sig.output);
1927 write!(w, "#[no_mangle]\npub extern \"C\" fn {}(", f.sig.ident).unwrap();
1930 write_method_params(w, &f.sig, "", types, Some(&gen_types), false, true);
1931 write!(w, " {{\n\t").unwrap();
1932 write_method_var_decl_body(w, &f.sig, "", types, Some(&gen_types), false);
1933 write!(w, "{}::{}", types.module_path, f.sig.ident).unwrap();
1935 let mut function_generic_args = Vec::new();
1936 maybe_write_generics(&mut function_generic_args, &f.sig.generics, &syn::PathArguments::None, types, true);
1937 if !function_generic_args.is_empty() {
1938 write!(w, "::{}", String::from_utf8(function_generic_args).unwrap()).unwrap();
1940 write!(w, "(").unwrap();
1942 write_method_call_params(w, &f.sig, "", types, Some(&gen_types), "", false);
1943 writeln!(w, "\n}}\n").unwrap();
1946 // ********************************
1947 // *** File/Crate Walking Logic ***
1948 // ********************************
1950 fn convert_priv_mod<'a, 'b: 'a, W: std::io::Write>(w: &mut W, w_uses: &mut HashSet<String, NonRandomHash>, libast: &'b FullLibraryAST, crate_types: &CrateTypes<'b>, out_dir: &str, mod_path: &str, module: &'b syn::ItemMod) {
1951 // We want to ignore all items declared in this module (as they are not pub), but we still need
1952 // to give the ImportResolver any use statements, so we copy them here.
1953 let mut use_items = Vec::new();
1954 for item in module.content.as_ref().unwrap().1.iter() {
1955 if let syn::Item::Use(_) = item {
1956 use_items.push(item);
1959 let import_resolver = ImportResolver::from_borrowed_items(mod_path.splitn(2, "::").next().unwrap(), libast, mod_path, &use_items);
1960 let mut types = TypeResolver::new(mod_path, import_resolver, crate_types);
1962 writeln!(w, "mod {} {{\n{}", module.ident, DEFAULT_IMPORTS).unwrap();
1963 for item in module.content.as_ref().unwrap().1.iter() {
1965 syn::Item::Mod(m) => convert_priv_mod(w, w_uses, libast, crate_types, out_dir, &format!("{}::{}", mod_path, module.ident), m),
1966 syn::Item::Impl(i) => {
1967 writeln_impl(w, w_uses, i, &mut types);
1972 writeln!(w, "}}").unwrap();
1975 /// Do the Real Work of mapping an original file to C-callable wrappers. Creates a new file at
1976 /// `out_path` and fills it with wrapper structs/functions to allow calling the things in the AST
1977 /// at `module` from C.
1978 fn convert_file<'a, 'b>(libast: &'a FullLibraryAST, crate_types: &CrateTypes<'a>, out_dir: &str, header_file: &mut File, cpp_header_file: &mut File) {
1979 for (module, astmod) in libast.modules.iter() {
1980 let orig_crate = module.splitn(2, "::").next().unwrap();
1981 let ASTModule { ref attrs, ref items, ref submods } = astmod;
1982 assert_eq!(export_status(&attrs), ExportStatus::Export);
1984 let new_file_path = if submods.is_empty() {
1985 format!("{}/{}.rs", out_dir, module.replace("::", "/"))
1986 } else if module != "" {
1987 format!("{}/{}/mod.rs", out_dir, module.replace("::", "/"))
1989 format!("{}/lib.rs", out_dir)
1991 let _ = std::fs::create_dir((&new_file_path.as_ref() as &std::path::Path).parent().unwrap());
1992 let mut out = std::fs::OpenOptions::new().write(true).create(true).truncate(true)
1993 .open(new_file_path).expect("Unable to open new src file");
1994 let mut out_uses = HashSet::default();
1996 writeln!(out, "// This file is Copyright its original authors, visible in version control").unwrap();
1997 writeln!(out, "// history and in the source files from which this was generated.").unwrap();
1998 writeln!(out, "//").unwrap();
1999 writeln!(out, "// This file is licensed under the license available in the LICENSE or LICENSE.md").unwrap();
2000 writeln!(out, "// file in the root of this repository or, if no such file exists, the same").unwrap();
2001 writeln!(out, "// license as that which applies to the original source files from which this").unwrap();
2002 writeln!(out, "// source was automatically generated.").unwrap();
2003 writeln!(out, "").unwrap();
2005 writeln_docs(&mut out, &attrs, "");
2008 // Special-case the top-level lib.rs with various lint allows and a pointer to the c_types
2009 // and bitcoin hand-written modules.
2010 writeln!(out, "//! C Bindings").unwrap();
2011 writeln!(out, "#![allow(unknown_lints)]").unwrap();
2012 writeln!(out, "#![allow(non_camel_case_types)]").unwrap();
2013 writeln!(out, "#![allow(non_snake_case)]").unwrap();
2014 writeln!(out, "#![allow(unused_imports)]").unwrap();
2015 writeln!(out, "#![allow(unused_variables)]").unwrap();
2016 writeln!(out, "#![allow(unused_mut)]").unwrap();
2017 writeln!(out, "#![allow(unused_parens)]").unwrap();
2018 writeln!(out, "#![allow(unused_unsafe)]").unwrap();
2019 writeln!(out, "#![allow(unused_braces)]").unwrap();
2020 // TODO: We need to map deny(missing_docs) in the source crate(s)
2021 //writeln!(out, "#![deny(missing_docs)]").unwrap();
2023 writeln!(out, "#![cfg_attr(not(feature = \"std\"), no_std)]").unwrap();
2024 writeln!(out, "#[cfg(not(any(feature = \"std\", feature = \"no-std\")))]").unwrap();
2025 writeln!(out, "compile_error!(\"at least one of the `std` or `no-std` features must be enabled\");").unwrap();
2026 writeln!(out, "extern crate alloc;").unwrap();
2028 writeln!(out, "pub mod version;").unwrap();
2029 writeln!(out, "pub mod c_types;").unwrap();
2030 writeln!(out, "pub mod bitcoin;").unwrap();
2032 writeln!(out, "{}", DEFAULT_IMPORTS).unwrap();
2036 writeln!(out, "pub mod {};", m).unwrap();
2039 eprintln!("Converting {} entries...", module);
2041 let import_resolver = ImportResolver::new(orig_crate, libast, module, items);
2042 let mut type_resolver = TypeResolver::new(module, import_resolver, crate_types);
2044 for item in items.iter() {
2046 syn::Item::Use(_) => {}, // Handled above
2047 syn::Item::Static(_) => {},
2048 syn::Item::Enum(e) => {
2049 if let syn::Visibility::Public(_) = e.vis {
2050 writeln_enum(&mut out, &e, &mut type_resolver, header_file, cpp_header_file);
2053 syn::Item::Impl(i) => {
2054 writeln_impl(&mut out, &mut out_uses, &i, &mut type_resolver);
2056 syn::Item::Struct(s) => {
2057 if let syn::Visibility::Public(_) = s.vis {
2058 writeln_struct(&mut out, &s, &mut type_resolver, header_file, cpp_header_file);
2061 syn::Item::Trait(t) => {
2062 if let syn::Visibility::Public(_) = t.vis {
2063 writeln_trait(&mut out, &t, &mut type_resolver, header_file, cpp_header_file);
2066 syn::Item::Mod(m) => {
2067 convert_priv_mod(&mut out, &mut out_uses, libast, crate_types, out_dir, &format!("{}::{}", module, m.ident), m);
2069 syn::Item::Const(c) => {
2070 // Re-export any primitive-type constants.
2071 if let syn::Visibility::Public(_) = c.vis {
2072 if let syn::Type::Path(p) = &*c.ty {
2073 let resolved_path = type_resolver.resolve_path(&p.path, None);
2074 if type_resolver.is_primitive(&resolved_path) {
2075 writeln_field_docs(&mut out, &c.attrs, "", &mut type_resolver, None, &*c.ty);
2076 writeln!(out, "\n#[no_mangle]").unwrap();
2077 writeln!(out, "pub static {}: {} = {}::{};", c.ident, resolved_path, module, c.ident).unwrap();
2082 syn::Item::Type(t) => {
2083 if let syn::Visibility::Public(_) = t.vis {
2084 match export_status(&t.attrs) {
2085 ExportStatus::Export => {},
2086 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
2087 ExportStatus::NotImplementable => panic!("(C-not implementable) must only appear on traits"),
2091 syn::Type::Path(p) => {
2092 let real_ty = type_resolver.resolve_path(&p.path, None);
2093 let real_generic_bounds = type_resolver.crate_types.opaques.get(&real_ty).map(|t| t.1).or(
2094 type_resolver.crate_types.priv_structs.get(&real_ty).map(|r| *r)).unwrap();
2095 let mut resolved_generics = t.generics.clone();
2097 // Assume blindly that the bounds in the struct definition where
2098 // clause matches any equivalent bounds on the type alias.
2099 assert!(resolved_generics.where_clause.is_none());
2100 resolved_generics.where_clause = real_generic_bounds.where_clause.clone();
2102 if let syn::PathArguments::AngleBracketed(real_generics) = &p.path.segments.last().unwrap().arguments {
2103 for (real_idx, real_param) in real_generics.args.iter().enumerate() {
2104 if let syn::GenericArgument::Type(syn::Type::Path(real_param_path)) = real_param {
2105 for param in resolved_generics.params.iter_mut() {
2106 if let syn::GenericParam::Type(type_param) = param {
2107 if Some(&type_param.ident) == real_param_path.path.get_ident() {
2108 if let syn::GenericParam::Type(real_type_param) = &real_generic_bounds.params[real_idx] {
2109 type_param.bounds = real_type_param.bounds.clone();
2110 type_param.default = real_type_param.default.clone();
2120 writeln_opaque(&mut out, &t.ident, &format!("{}", t.ident), &resolved_generics, &t.attrs, &type_resolver, header_file, cpp_header_file)},
2125 syn::Item::Fn(f) => {
2126 if let syn::Visibility::Public(_) = f.vis {
2127 writeln_fn(&mut out, &f, &mut type_resolver);
2130 syn::Item::Macro(_) => {},
2131 syn::Item::Verbatim(_) => {},
2132 syn::Item::ExternCrate(_) => {},
2133 _ => unimplemented!(),
2137 for use_stmt in out_uses {
2138 writeln!(out, "{}", use_stmt).unwrap();
2141 out.flush().unwrap();
2146 /// Walk the FullLibraryAST, determining if impl aliases need to be marked cloneable.
2147 fn walk_ast_second_pass<'a>(ast_storage: &'a FullLibraryAST, crate_types: &CrateTypes<'a>) {
2148 for (module, astmod) in ast_storage.modules.iter() {
2149 let orig_crate = module.splitn(2, "::").next().unwrap();
2150 let ASTModule { ref attrs, ref items, .. } = astmod;
2151 assert_eq!(export_status(&attrs), ExportStatus::Export);
2153 let import_resolver = ImportResolver::new(orig_crate, ast_storage, module, items);
2154 let mut types = TypeResolver::new(module, import_resolver, crate_types);
2156 for item in items.iter() {
2158 syn::Item::Impl(i) => {
2159 match export_status(&i.attrs) {
2160 ExportStatus::Export => {},
2161 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
2162 ExportStatus::NotImplementable => panic!("(C-not implementable) must only appear on traits"),
2164 if let Some(trait_path) = i.trait_.as_ref() {
2165 if path_matches_nongeneric(&trait_path.1, &["core", "clone", "Clone"]) ||
2166 path_matches_nongeneric(&trait_path.1, &["Clone"])
2168 if let &syn::Type::Path(ref p) = &*i.self_ty {
2169 if let Some(resolved_path) = types.maybe_resolve_path(&p.path, None) {
2170 create_alias_for_impl(resolved_path, i, &mut types, |aliased_impl, types| {
2171 if let &syn::Type::Path(ref p) = &*aliased_impl.self_ty {
2172 if let Some(resolved_aliased_path) = types.maybe_resolve_path(&p.path, None) {
2173 crate_types.set_clonable("crate::".to_owned() + &resolved_aliased_path);
2188 fn walk_private_mod<'a>(ast_storage: &'a FullLibraryAST, orig_crate: &str, module: String, items: &'a syn::ItemMod, crate_types: &mut CrateTypes<'a>) {
2189 let import_resolver = ImportResolver::new(orig_crate, ast_storage, &module, &items.content.as_ref().unwrap().1);
2190 for item in items.content.as_ref().unwrap().1.iter() {
2192 syn::Item::Mod(m) => walk_private_mod(ast_storage, orig_crate, format!("{}::{}", module, m.ident), m, crate_types),
2193 syn::Item::Impl(i) => {
2194 if let &syn::Type::Path(ref p) = &*i.self_ty {
2195 if let Some(trait_path) = i.trait_.as_ref() {
2196 if let Some(tp) = import_resolver.maybe_resolve_path(&trait_path.1, None) {
2197 if let Some(sp) = import_resolver.maybe_resolve_path(&p.path, None) {
2198 match crate_types.trait_impls.entry(sp) {
2199 hash_map::Entry::Occupied(mut e) => { e.get_mut().push(tp); },
2200 hash_map::Entry::Vacant(e) => { e.insert(vec![tp]); },
2212 /// Walk the FullLibraryAST, deciding how things will be mapped and adding tracking to CrateTypes.
2213 fn walk_ast_first_pass<'a>(ast_storage: &'a FullLibraryAST, crate_types: &mut CrateTypes<'a>) {
2214 for (module, astmod) in ast_storage.modules.iter() {
2215 let ASTModule { ref attrs, ref items, submods: _ } = astmod;
2216 assert_eq!(export_status(&attrs), ExportStatus::Export);
2217 let orig_crate = module.splitn(2, "::").next().unwrap();
2218 let import_resolver = ImportResolver::new(orig_crate, ast_storage, module, items);
2220 for item in items.iter() {
2222 syn::Item::Struct(s) => {
2223 if let syn::Visibility::Public(_) = s.vis {
2224 let struct_path = format!("{}::{}", module, s.ident);
2225 match export_status(&s.attrs) {
2226 ExportStatus::Export => {},
2227 ExportStatus::NoExport|ExportStatus::TestOnly => {
2228 crate_types.priv_structs.insert(struct_path, &s.generics);
2231 ExportStatus::NotImplementable => panic!("(C-not implementable) must only appear on traits"),
2233 crate_types.opaques.insert(struct_path, (&s.ident, &s.generics));
2236 syn::Item::Trait(t) => {
2237 if let syn::Visibility::Public(_) = t.vis {
2238 match export_status(&t.attrs) {
2239 ExportStatus::Export|ExportStatus::NotImplementable => {},
2240 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
2242 let trait_path = format!("{}::{}", module, t.ident);
2243 walk_supertraits!(t, None, (
2244 ("Clone", _, _) => {
2245 crate_types.set_clonable("crate::".to_owned() + &trait_path);
2249 crate_types.traits.insert(trait_path, &t);
2252 syn::Item::Type(t) => {
2253 if let syn::Visibility::Public(_) = t.vis {
2254 match export_status(&t.attrs) {
2255 ExportStatus::Export => {},
2256 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
2257 ExportStatus::NotImplementable => panic!("(C-not implementable) must only appear on traits"),
2259 let type_path = format!("{}::{}", module, t.ident);
2261 syn::Type::Path(p) => {
2262 // If its a path with no generics, assume we don't map the aliased type and map it opaque
2263 let args_obj = p.path.segments.last().unwrap().arguments.clone();
2264 match crate_types.reverse_alias_map.entry(import_resolver.maybe_resolve_path(&p.path, None).unwrap()) {
2265 hash_map::Entry::Occupied(mut e) => { e.get_mut().push((type_path.clone(), args_obj)); },
2266 hash_map::Entry::Vacant(e) => { e.insert(vec![(type_path.clone(), args_obj)]); },
2269 crate_types.opaques.insert(type_path, (&t.ident, &t.generics));
2272 crate_types.type_aliases.insert(type_path, import_resolver.resolve_imported_refs((*t.ty).clone()));
2277 syn::Item::Enum(e) if is_enum_opaque(e) => {
2278 if let syn::Visibility::Public(_) = e.vis {
2279 match export_status(&e.attrs) {
2280 ExportStatus::Export => {},
2281 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
2282 ExportStatus::NotImplementable => panic!("(C-not implementable) must only appear on traits"),
2284 let enum_path = format!("{}::{}", module, e.ident);
2285 crate_types.opaques.insert(enum_path, (&e.ident, &e.generics));
2288 syn::Item::Enum(e) => {
2289 if let syn::Visibility::Public(_) = e.vis {
2290 match export_status(&e.attrs) {
2291 ExportStatus::Export => {},
2292 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
2293 ExportStatus::NotImplementable => panic!("(C-not implementable) must only appear on traits"),
2295 let enum_path = format!("{}::{}", module, e.ident);
2296 crate_types.mirrored_enums.insert(enum_path, &e);
2299 syn::Item::Impl(i) => {
2300 if let &syn::Type::Path(ref p) = &*i.self_ty {
2301 if let Some(trait_path) = i.trait_.as_ref() {
2302 if path_matches_nongeneric(&trait_path.1, &["core", "clone", "Clone"]) ||
2303 path_matches_nongeneric(&trait_path.1, &["Clone"]) {
2304 if let Some(full_path) = import_resolver.maybe_resolve_path(&p.path, None) {
2305 crate_types.set_clonable("crate::".to_owned() + &full_path);
2308 if let Some(tp) = import_resolver.maybe_resolve_path(&trait_path.1, None) {
2309 if let Some(sp) = import_resolver.maybe_resolve_path(&p.path, None) {
2310 match crate_types.trait_impls.entry(sp) {
2311 hash_map::Entry::Occupied(mut e) => { e.get_mut().push(tp); },
2312 hash_map::Entry::Vacant(e) => { e.insert(vec![tp]); },
2319 syn::Item::Mod(m) => walk_private_mod(ast_storage, orig_crate, format!("{}::{}", module, m.ident), m, crate_types),
2327 let args: Vec<String> = env::args().collect();
2328 if args.len() != 5 {
2329 eprintln!("Usage: target/dir derived_templates.rs extra/includes.h extra/cpp/includes.hpp");
2333 let mut derived_templates = std::fs::OpenOptions::new().write(true).create(true).truncate(true)
2334 .open(&args[2]).expect("Unable to open new header file");
2335 writeln!(&mut derived_templates, "{}", DEFAULT_IMPORTS).unwrap();
2336 let mut header_file = std::fs::OpenOptions::new().write(true).create(true).truncate(true)
2337 .open(&args[3]).expect("Unable to open new header file");
2338 let mut cpp_header_file = std::fs::OpenOptions::new().write(true).create(true).truncate(true)
2339 .open(&args[4]).expect("Unable to open new header file");
2341 writeln!(header_file, "#if defined(__GNUC__)").unwrap();
2342 writeln!(header_file, "#define MUST_USE_STRUCT __attribute__((warn_unused))").unwrap();
2343 writeln!(header_file, "#define MUST_USE_RES __attribute__((warn_unused_result))").unwrap();
2344 writeln!(header_file, "#else").unwrap();
2345 writeln!(header_file, "#define MUST_USE_STRUCT").unwrap();
2346 writeln!(header_file, "#define MUST_USE_RES").unwrap();
2347 writeln!(header_file, "#endif").unwrap();
2348 writeln!(header_file, "#if defined(__clang__)").unwrap();
2349 writeln!(header_file, "#define NONNULL_PTR _Nonnull").unwrap();
2350 writeln!(header_file, "#else").unwrap();
2351 writeln!(header_file, "#define NONNULL_PTR").unwrap();
2352 writeln!(header_file, "#endif").unwrap();
2353 writeln!(cpp_header_file, "#include <string.h>\nnamespace LDK {{").unwrap();
2355 // Write a few manually-defined types into the C++ header file
2356 write_cpp_wrapper(&mut cpp_header_file, "Str", true, None);
2358 // First parse the full crate's ASTs, caching them so that we can hold references to the AST
2359 // objects in other datastructures:
2360 let mut lib_src = String::new();
2361 std::io::stdin().lock().read_to_string(&mut lib_src).unwrap();
2362 let lib_syntax = syn::parse_file(&lib_src).expect("Unable to parse file");
2363 let libast = FullLibraryAST::load_lib(lib_syntax);
2365 // ...then walk the ASTs tracking what types we will map, and how, so that we can resolve them
2366 // when parsing other file ASTs...
2367 let mut libtypes = CrateTypes::new(&mut derived_templates, &libast);
2368 walk_ast_first_pass(&libast, &mut libtypes);
2370 // ... using the generated data, determine a few additional fields, specifically which type
2371 // aliases are to be clone-able...
2372 walk_ast_second_pass(&libast, &libtypes);
2374 // ... finally, do the actual file conversion/mapping, writing out types as we go.
2375 convert_file(&libast, &libtypes, &args[1], &mut header_file, &mut cpp_header_file);
2377 // For container templates which we created while walking the crate, make sure we add C++
2378 // mapped types so that C++ users can utilize the auto-destructors available.
2379 for (ty, has_destructor) in libtypes.templates_defined.borrow().iter() {
2380 write_cpp_wrapper(&mut cpp_header_file, ty, *has_destructor, None);
2382 writeln!(cpp_header_file, "}}").unwrap();
2384 header_file.flush().unwrap();
2385 cpp_header_file.flush().unwrap();
2386 derived_templates.flush().unwrap();
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