1 //! Converts a rust crate into a rust crate containing a number of C-exported wrapper functions and
2 //! classes (which is exportable using cbindgen).
3 //! In general, supports convering:
4 //! * structs as a pointer to the underlying type (either owned or not owned),
5 //! * traits as a void-ptr plus a jump table,
6 //! * enums as an equivalent enum with all the inner fields mapped to the mapped types,
7 //! * certain containers (tuples, slices, Vecs, Options, and Results currently) to a concrete
8 //! version of a defined container template.
10 //! It also generates relevant memory-management functions and free-standing functions with
11 //! parameters mapped.
13 use std::collections::HashMap;
16 use std::io::{Read, Write};
20 use proc_macro2::{TokenTree, TokenStream, Span};
27 // *************************************
28 // *** Manually-expanded conversions ***
29 // *************************************
31 /// Because we don't expand macros, any code that we need to generated based on their contents has
32 /// to be completely manual. In this case its all just serialization, so its not too hard.
33 fn convert_macro<W: std::io::Write>(w: &mut W, macro_path: &syn::Path, stream: &TokenStream, types: &TypeResolver) {
34 assert_eq!(macro_path.segments.len(), 1);
35 match &format!("{}", macro_path.segments.iter().next().unwrap().ident) as &str {
36 "impl_writeable" | "impl_writeable_len_match" => {
37 let struct_for = if let TokenTree::Ident(i) = stream.clone().into_iter().next().unwrap() { i } else { unimplemented!(); };
38 if let Some(s) = types.maybe_resolve_ident(&struct_for) {
39 if !types.crate_types.opaques.get(&s).is_some() { return; }
40 writeln!(w, "#[no_mangle]").unwrap();
41 writeln!(w, "pub extern \"C\" fn {}_write(obj: *const {}) -> crate::c_types::derived::CVec_u8Z {{", struct_for, struct_for).unwrap();
42 writeln!(w, "\tcrate::c_types::serialize_obj(unsafe {{ &(*(*obj).inner) }})").unwrap();
43 writeln!(w, "}}").unwrap();
44 writeln!(w, "#[no_mangle]").unwrap();
45 writeln!(w, "pub extern \"C\" fn {}_read(ser: crate::c_types::u8slice) -> {} {{", struct_for, struct_for).unwrap();
46 writeln!(w, "\tif let Ok(res) = crate::c_types::deserialize_obj(ser) {{").unwrap();
47 writeln!(w, "\t\t{} {{ inner: Box::into_raw(Box::new(res)), is_owned: true }}", struct_for).unwrap();
48 writeln!(w, "\t}} else {{").unwrap();
49 writeln!(w, "\t\t{} {{ inner: std::ptr::null_mut(), is_owned: true }}", struct_for).unwrap();
50 writeln!(w, "\t}}\n}}").unwrap();
57 /// Convert "impl trait_path for for_obj { .. }" for manually-mapped types (ie (de)serialization)
58 fn maybe_convert_trait_impl<W: std::io::Write>(w: &mut W, trait_path: &syn::Path, for_obj: &syn::Ident, types: &TypeResolver) {
59 if let Some(t) = types.maybe_resolve_path(&trait_path, None) {
60 let s = types.maybe_resolve_ident(for_obj).unwrap();
61 if !types.crate_types.opaques.get(&s).is_some() { return; }
63 "util::ser::Writeable" => {
64 writeln!(w, "#[no_mangle]").unwrap();
65 writeln!(w, "pub extern \"C\" fn {}_write(obj: *const {}) -> crate::c_types::derived::CVec_u8Z {{", for_obj, for_obj).unwrap();
66 writeln!(w, "\tcrate::c_types::serialize_obj(unsafe {{ &(*(*obj).inner) }})").unwrap();
67 writeln!(w, "}}").unwrap();
69 "util::ser::Readable" => {
70 writeln!(w, "#[no_mangle]").unwrap();
71 writeln!(w, "pub extern \"C\" fn {}_read(ser: crate::c_types::u8slice) -> {} {{", for_obj, for_obj).unwrap();
72 writeln!(w, "\tif let Ok(res) = crate::c_types::deserialize_obj(ser) {{").unwrap();
73 writeln!(w, "\t\t{} {{ inner: Box::into_raw(Box::new(res)), is_owned: true }}", for_obj).unwrap();
74 writeln!(w, "\t}} else {{").unwrap();
75 writeln!(w, "\t\t{} {{ inner: std::ptr::null_mut(), is_owned: true }}", for_obj).unwrap();
76 writeln!(w, "\t}}\n}}").unwrap();
83 // *******************************
84 // *** Per-Type Printing Logic ***
85 // *******************************
87 macro_rules! walk_supertraits { ($t: expr, $types: expr, ($( $pat: pat => $e: expr),*) ) => { {
88 if $t.colon_token.is_some() {
89 for st in $t.supertraits.iter() {
91 syn::TypeParamBound::Trait(supertrait) => {
92 if supertrait.paren_token.is_some() || supertrait.lifetimes.is_some() {
95 if let Some(ident) = supertrait.path.get_ident() {
96 match (&format!("{}", ident) as &str, &ident) {
100 let path = $types.resolve_path(&supertrait.path, None);
101 match (&path as &str, &supertrait.path.segments.iter().last().unwrap().ident) {
106 syn::TypeParamBound::Lifetime(_) => unimplemented!(),
112 /// Gets a HashMap from name idents to the bounding trait for associated types.
113 /// eg if a native trait has a "type T = TraitA", this will return a HashMap containing a mapping
114 /// from "T" to "TraitA".
115 fn learn_associated_types<'a>(t: &'a syn::ItemTrait) -> HashMap<&'a syn::Ident, &'a syn::Ident> {
116 let mut associated_types = HashMap::new();
117 for item in t.items.iter() {
119 &syn::TraitItem::Type(ref t) => {
120 if t.default.is_some() || t.generics.lt_token.is_some() { unimplemented!(); }
121 let mut bounds_iter = t.bounds.iter();
122 match bounds_iter.next().unwrap() {
123 syn::TypeParamBound::Trait(tr) => {
124 assert_simple_bound(&tr);
125 associated_types.insert(&t.ident, assert_single_path_seg(&tr.path));
127 _ => unimplemented!(),
129 if bounds_iter.next().is_some() { unimplemented!(); }
137 /// Prints a C-mapped trait object containing a void pointer and a jump table for each function in
138 /// the original trait.
139 /// Implements the native Rust trait and relevant parent traits for the new C-mapped trait.
141 /// Finally, implements Deref<MappedTrait> for MappedTrait which allows its use in types which need
142 /// a concrete Deref to the Rust trait.
143 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) {
144 let trait_name = format!("{}", t.ident);
145 match export_status(&t.attrs) {
146 ExportStatus::Export => {},
147 ExportStatus::NoExport|ExportStatus::TestOnly => return,
149 writeln_docs(w, &t.attrs, "");
151 let mut gen_types = GenericTypes::new();
152 assert!(gen_types.learn_generics(&t.generics, types));
154 writeln!(w, "#[repr(C)]\npub struct {} {{", trait_name).unwrap();
155 writeln!(w, "\tpub this_arg: *mut c_void,").unwrap();
156 let associated_types = learn_associated_types(t);
157 let mut generated_fields = Vec::new(); // Every field's name except this_arg, used in Clone generation
158 for item in t.items.iter() {
160 &syn::TraitItem::Method(ref m) => {
161 match export_status(&m.attrs) {
162 ExportStatus::NoExport => {
163 // NoExport in this context means we'll hit an unimplemented!() at runtime,
167 ExportStatus::Export => {},
168 ExportStatus::TestOnly => continue,
170 if m.default.is_some() { unimplemented!(); }
172 gen_types.push_ctx();
173 assert!(gen_types.learn_generics(&m.sig.generics, types));
175 writeln_docs(w, &m.attrs, "\t");
177 if let syn::ReturnType::Type(_, rtype) = &m.sig.output {
178 if let syn::Type::Reference(r) = &**rtype {
179 // We have to do quite a dance for trait functions which return references
180 // - they ultimately require us to have a native Rust object stored inside
181 // our concrete trait to return a reference to. However, users may wish to
182 // update the value to be returned each time the function is called (or, to
183 // make C copies of Rust impls equivalent, we have to be able to).
185 // Thus, we store a copy of the C-mapped type (which is just a pointer to
186 // the Rust type and a flag to indicate whether deallocation needs to
187 // happen) as well as provide an Option<>al function pointer which is
188 // called when the trait method is called which allows updating on the fly.
189 write!(w, "\tpub {}: ", m.sig.ident).unwrap();
190 generated_fields.push(format!("{}", m.sig.ident));
191 types.write_c_type(w, &*r.elem, Some(&gen_types), false);
192 writeln!(w, ",").unwrap();
193 writeln!(w, "\t/// Fill in the {} field as a reference to it will be given to Rust after this returns", m.sig.ident).unwrap();
194 writeln!(w, "\t/// Note that this takes a pointer to this object, not the this_ptr like other methods do").unwrap();
195 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();
196 writeln!(w, "\tpub set_{}: Option<extern \"C\" fn(&{})>,", m.sig.ident, trait_name).unwrap();
197 generated_fields.push(format!("set_{}", m.sig.ident));
198 // Note that cbindgen will now generate
199 // typedef struct Thing {..., set_thing: (const Thing*), ...} Thing;
200 // which does not compile since Thing is not defined before it is used.
201 writeln!(extra_headers, "struct LDK{};", trait_name).unwrap();
202 writeln!(extra_headers, "typedef struct LDK{} LDK{};", trait_name, trait_name).unwrap();
206 // Sadly, this currently doesn't do what we want, but it should be easy to get
207 // cbindgen to support it. See https://github.com/eqrion/cbindgen/issues/531
208 writeln!(w, "\t#[must_use]").unwrap();
211 write!(w, "\tpub {}: extern \"C\" fn (", m.sig.ident).unwrap();
212 generated_fields.push(format!("{}", m.sig.ident));
213 write_method_params(w, &m.sig, &associated_types, "c_void", types, Some(&gen_types), true, false);
214 writeln!(w, ",").unwrap();
218 &syn::TraitItem::Type(_) => {},
219 _ => unimplemented!(),
222 // Add functions which may be required for supertrait implementations.
223 walk_supertraits!(t, types, (
225 writeln!(w, "\tpub clone: Option<extern \"C\" fn (this_arg: *const c_void) -> *mut c_void>,").unwrap();
226 generated_fields.push("clone".to_owned());
228 ("std::cmp::Eq", _) => {
229 writeln!(w, "\tpub eq: extern \"C\" fn (this_arg: *const c_void, other_arg: *const c_void) -> bool,").unwrap();
230 generated_fields.push("eq".to_owned());
232 ("std::hash::Hash", _) => {
233 writeln!(w, "\tpub hash: extern \"C\" fn (this_arg: *const c_void) -> u64,").unwrap();
234 generated_fields.push("hash".to_owned());
236 ("Send", _) => {}, ("Sync", _) => {},
238 // For in-crate supertraits, just store a C-mapped copy of the supertrait as a member.
239 if types.crate_types.traits.get(s).is_none() { unimplemented!(); }
240 writeln!(w, "\tpub {}: crate::{},", i, s).unwrap();
241 generated_fields.push(format!("{}", i));
244 writeln!(w, "\tpub free: Option<extern \"C\" fn(this_arg: *mut c_void)>,").unwrap();
245 generated_fields.push("free".to_owned());
246 writeln!(w, "}}").unwrap();
247 // Implement supertraits for the C-mapped struct.
248 walk_supertraits!(t, types, (
249 ("Send", _) => writeln!(w, "unsafe impl Send for {} {{}}", trait_name).unwrap(),
250 ("Sync", _) => writeln!(w, "unsafe impl Sync for {} {{}}", trait_name).unwrap(),
251 ("std::cmp::Eq", _) => {
252 writeln!(w, "impl std::cmp::Eq for {} {{}}", trait_name).unwrap();
253 writeln!(w, "impl std::cmp::PartialEq for {} {{", trait_name).unwrap();
254 writeln!(w, "\tfn eq(&self, o: &Self) -> bool {{ (self.eq)(self.this_arg, o.this_arg) }}\n}}").unwrap();
256 ("std::hash::Hash", _) => {
257 writeln!(w, "impl std::hash::Hash for {} {{", trait_name).unwrap();
258 writeln!(w, "\tfn hash<H: std::hash::Hasher>(&self, hasher: &mut H) {{ hasher.write_u64((self.hash)(self.this_arg)) }}\n}}").unwrap();
261 writeln!(w, "impl Clone for {} {{", trait_name).unwrap();
262 writeln!(w, "\tfn clone(&self) -> Self {{").unwrap();
263 writeln!(w, "\t\tSelf {{").unwrap();
264 writeln!(w, "\t\tthis_arg: if let Some(f) = self.clone {{ (f)(self.this_arg) }} else {{ self.this_arg }},").unwrap();
265 for field in generated_fields.iter() {
266 writeln!(w, "\t\t\t{}: self.{}.clone(),", field, field).unwrap();
268 writeln!(w, "\t\t}}\n\t}}\n}}").unwrap();
271 if s != "util::events::MessageSendEventsProvider" { unimplemented!(); }
272 // XXX: We straight-up cheat here - instead of bothering to get the trait object we
273 // just print what we need since this is only used in one place.
274 writeln!(w, "impl lightning::{} for {} {{", s, trait_name).unwrap();
275 writeln!(w, "\tfn get_and_clear_pending_msg_events(&self) -> Vec<lightning::util::events::MessageSendEvent> {{").unwrap();
276 writeln!(w, "\t\t<crate::{} as lightning::{}>::get_and_clear_pending_msg_events(&self.{})", s, s, i).unwrap();
277 writeln!(w, "\t}}\n}}").unwrap();
281 // Finally, implement the original Rust trait for the newly created mapped trait.
282 writeln!(w, "\nuse {}::{}::{} as rust{};", types.orig_crate, types.module_path, t.ident, trait_name).unwrap();
283 write!(w, "impl rust{}", t.ident).unwrap();
284 maybe_write_generics(w, &t.generics, types, false);
285 writeln!(w, " for {} {{", trait_name).unwrap();
286 for item in t.items.iter() {
288 syn::TraitItem::Method(m) => {
289 if let ExportStatus::TestOnly = export_status(&m.attrs) { continue; }
290 if m.default.is_some() { unimplemented!(); }
291 if m.sig.constness.is_some() || m.sig.asyncness.is_some() || m.sig.unsafety.is_some() ||
292 m.sig.abi.is_some() || m.sig.variadic.is_some() {
295 gen_types.push_ctx();
296 assert!(gen_types.learn_generics(&m.sig.generics, types));
297 write!(w, "\tfn {}", m.sig.ident).unwrap();
298 types.write_rust_generic_param(w, Some(&gen_types), m.sig.generics.params.iter());
299 write!(w, "(").unwrap();
300 for inp in m.sig.inputs.iter() {
302 syn::FnArg::Receiver(recv) => {
303 if !recv.attrs.is_empty() || recv.reference.is_none() { unimplemented!(); }
304 write!(w, "&").unwrap();
305 if let Some(lft) = &recv.reference.as_ref().unwrap().1 {
306 write!(w, "'{} ", lft.ident).unwrap();
308 if recv.mutability.is_some() {
309 write!(w, "mut self").unwrap();
311 write!(w, "self").unwrap();
314 syn::FnArg::Typed(arg) => {
315 if !arg.attrs.is_empty() { unimplemented!(); }
317 syn::Pat::Ident(ident) => {
318 if !ident.attrs.is_empty() || ident.by_ref.is_some() ||
319 ident.mutability.is_some() || ident.subpat.is_some() {
322 write!(w, ", {}{}: ", if types.skip_arg(&*arg.ty, Some(&gen_types)) { "_" } else { "" }, ident.ident).unwrap();
324 _ => unimplemented!(),
326 types.write_rust_type(w, Some(&gen_types), &*arg.ty);
330 write!(w, ")").unwrap();
331 match &m.sig.output {
332 syn::ReturnType::Type(_, rtype) => {
333 write!(w, " -> ").unwrap();
334 types.write_rust_type(w, Some(&gen_types), &*rtype)
338 write!(w, " {{\n\t\t").unwrap();
339 match export_status(&m.attrs) {
340 ExportStatus::NoExport => {
345 if let syn::ReturnType::Type(_, rtype) = &m.sig.output {
346 if let syn::Type::Reference(r) = &**rtype {
347 assert_eq!(m.sig.inputs.len(), 1); // Must only take self!
348 writeln!(w, "if let Some(f) = self.set_{} {{", m.sig.ident).unwrap();
349 writeln!(w, "\t\t\t(f)(self);").unwrap();
350 write!(w, "\t\t}}\n\t\t").unwrap();
351 types.write_from_c_conversion_to_ref_prefix(w, &*r.elem, Some(&gen_types));
352 write!(w, "self.{}", m.sig.ident).unwrap();
353 types.write_from_c_conversion_to_ref_suffix(w, &*r.elem, Some(&gen_types));
354 writeln!(w, "\n\t}}").unwrap();
359 write_method_var_decl_body(w, &m.sig, "\t", types, Some(&gen_types), true);
360 write!(w, "(self.{})(", m.sig.ident).unwrap();
361 write_method_call_params(w, &m.sig, &associated_types, "\t", types, Some(&gen_types), "", true);
363 writeln!(w, "\n\t}}").unwrap();
366 &syn::TraitItem::Type(ref t) => {
367 if t.default.is_some() || t.generics.lt_token.is_some() { unimplemented!(); }
368 let mut bounds_iter = t.bounds.iter();
369 match bounds_iter.next().unwrap() {
370 syn::TypeParamBound::Trait(tr) => {
371 writeln!(w, "\ttype {} = crate::{};", t.ident, types.resolve_path(&tr.path, Some(&gen_types))).unwrap();
373 _ => unimplemented!(),
375 if bounds_iter.next().is_some() { unimplemented!(); }
377 _ => unimplemented!(),
380 writeln!(w, "}}\n").unwrap();
381 writeln!(w, "// We're essentially a pointer already, or at least a set of pointers, so allow us to be used").unwrap();
382 writeln!(w, "// directly as a Deref trait in higher-level structs:").unwrap();
383 writeln!(w, "impl std::ops::Deref for {} {{\n\ttype Target = Self;", trait_name).unwrap();
384 writeln!(w, "\tfn deref(&self) -> &Self {{\n\t\tself\n\t}}\n}}").unwrap();
386 writeln!(w, "/// Calls the free function if one is set").unwrap();
387 writeln!(w, "#[no_mangle]\npub extern \"C\" fn {}_free(this_ptr: {}) {{ }}", trait_name, trait_name).unwrap();
388 writeln!(w, "impl Drop for {} {{", trait_name).unwrap();
389 writeln!(w, "\tfn drop(&mut self) {{").unwrap();
390 writeln!(w, "\t\tif let Some(f) = self.free {{").unwrap();
391 writeln!(w, "\t\t\tf(self.this_arg);").unwrap();
392 writeln!(w, "\t\t}}\n\t}}\n}}").unwrap();
394 write_cpp_wrapper(cpp_headers, &trait_name, true);
395 types.trait_declared(&t.ident, t);
398 /// Write out a simple "opaque" type (eg structs) which contain a pointer to the native Rust type
399 /// and a flag to indicate whether Drop'ing the mapped struct drops the underlying Rust type.
401 /// Also writes out a _free function and a C++ wrapper which handles calling _free.
402 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) {
403 // If we directly read the original type by its original name, cbindgen hits
404 // https://github.com/eqrion/cbindgen/issues/286 Thus, instead, we import it as a temporary
405 // name and then reference it by that name, which works around the issue.
406 write!(w, "\nuse {}::{}::{} as native{}Import;\ntype native{} = native{}Import", types.orig_crate, types.module_path, ident, ident, ident, ident).unwrap();
407 maybe_write_generics(w, &generics, &types, true);
408 writeln!(w, ";\n").unwrap();
409 writeln!(extra_headers, "struct native{}Opaque;\ntypedef struct native{}Opaque LDKnative{};", ident, ident, ident).unwrap();
410 writeln_docs(w, &attrs, "");
411 writeln!(w, "#[must_use]\n#[repr(C)]\npub struct {} {{\n\t/// Nearly everywhere, inner must be non-null, however in places where", struct_name).unwrap();
412 writeln!(w, "\t/// the Rust equivalent takes an Option, it may be set to null to indicate None.").unwrap();
413 writeln!(w, "\tpub inner: *mut native{},\n\tpub is_owned: bool,\n}}\n", ident).unwrap();
414 writeln!(w, "impl Drop for {} {{\n\tfn drop(&mut self) {{", struct_name).unwrap();
415 writeln!(w, "\t\tif self.is_owned && !self.inner.is_null() {{").unwrap();
416 writeln!(w, "\t\t\tlet _ = unsafe {{ Box::from_raw(self.inner) }};\n\t\t}}\n\t}}\n}}").unwrap();
417 writeln!(w, "#[no_mangle]\npub extern \"C\" fn {}_free(this_ptr: {}) {{ }}", struct_name, struct_name).unwrap();
418 writeln!(w, "#[allow(unused)]").unwrap();
419 writeln!(w, "/// Used only if an object of this type is returned as a trait impl by a method").unwrap();
420 writeln!(w, "extern \"C\" fn {}_free_void(this_ptr: *mut c_void) {{", struct_name).unwrap();
421 writeln!(w, "\tunsafe {{ let _ = Box::from_raw(this_ptr as *mut native{}); }}\n}}", struct_name).unwrap();
422 writeln!(w, "#[allow(unused)]").unwrap();
423 writeln!(w, "/// When moving out of the pointer, we have to ensure we aren't a reference, this makes that easy").unwrap();
424 writeln!(w, "impl {} {{", struct_name).unwrap();
425 writeln!(w, "\tpub(crate) fn take_ptr(mut self) -> *mut native{} {{", struct_name).unwrap();
426 writeln!(w, "\t\tassert!(self.is_owned);").unwrap();
427 writeln!(w, "\t\tlet ret = self.inner;").unwrap();
428 writeln!(w, "\t\tself.inner = std::ptr::null_mut();").unwrap();
429 writeln!(w, "\t\tret").unwrap();
430 writeln!(w, "\t}}\n}}").unwrap();
432 'attr_loop: for attr in attrs.iter() {
433 let tokens_clone = attr.tokens.clone();
434 let mut token_iter = tokens_clone.into_iter();
435 if let Some(token) = token_iter.next() {
437 TokenTree::Group(g) => {
438 if format!("{}", single_ident_generic_path_to_ident(&attr.path).unwrap()) == "derive" {
439 for id in g.stream().into_iter() {
440 if let TokenTree::Ident(i) = id {
442 writeln!(w, "impl Clone for {} {{", struct_name).unwrap();
443 writeln!(w, "\tfn clone(&self) -> Self {{").unwrap();
444 writeln!(w, "\t\tSelf {{").unwrap();
445 writeln!(w, "\t\t\tinner: Box::into_raw(Box::new(unsafe {{ &*self.inner }}.clone())),").unwrap();
446 writeln!(w, "\t\t\tis_owned: true,").unwrap();
447 writeln!(w, "\t\t}}\n\t}}\n}}").unwrap();
448 writeln!(w, "#[allow(unused)]").unwrap();
449 writeln!(w, "/// Used only if an object of this type is returned as a trait impl by a method").unwrap();
450 writeln!(w, "pub(crate) extern \"C\" fn {}_clone_void(this_ptr: *const c_void) -> *mut c_void {{", struct_name).unwrap();
451 writeln!(w, "\tBox::into_raw(Box::new(unsafe {{ (*(this_ptr as *mut native{})).clone() }})) as *mut c_void", struct_name).unwrap();
452 writeln!(w, "}}").unwrap();
453 writeln!(w, "#[no_mangle]").unwrap();
454 writeln!(w, "pub extern \"C\" fn {}_clone(orig: &{}) -> {} {{", struct_name, struct_name, struct_name).unwrap();
455 writeln!(w, "\t{} {{ inner: Box::into_raw(Box::new(unsafe {{ &*orig.inner }}.clone())), is_owned: true }}", struct_name).unwrap();
456 writeln!(w, "}}").unwrap();
468 write_cpp_wrapper(cpp_headers, &format!("{}", ident), true);
471 /// Writes out all the relevant mappings for a Rust struct, deferring to writeln_opaque to generate
472 /// the struct itself, and then writing getters and setters for public, understood-type fields and
473 /// a constructor if every field is public.
474 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) {
475 let struct_name = &format!("{}", s.ident);
476 let export = export_status(&s.attrs);
478 ExportStatus::Export => {},
479 ExportStatus::TestOnly => return,
480 ExportStatus::NoExport => {
481 types.struct_ignored(&s.ident);
486 writeln_opaque(w, &s.ident, struct_name, &s.generics, &s.attrs, types, extra_headers, cpp_headers);
488 eprintln!("exporting fields for {}", struct_name);
489 if let syn::Fields::Named(fields) = &s.fields {
490 let mut gen_types = GenericTypes::new();
491 assert!(gen_types.learn_generics(&s.generics, types));
493 let mut all_fields_settable = true;
494 for field in fields.named.iter() {
495 if let syn::Visibility::Public(_) = field.vis {
496 let export = export_status(&field.attrs);
498 ExportStatus::Export => {},
499 ExportStatus::NoExport|ExportStatus::TestOnly => {
500 all_fields_settable = false;
505 if let Some(ident) = &field.ident {
506 let ref_type = syn::Type::Reference(syn::TypeReference {
507 and_token: syn::Token!(&)(Span::call_site()), lifetime: None, mutability: None,
508 elem: Box::new(field.ty.clone()) });
509 if types.understood_c_type(&ref_type, Some(&gen_types)) {
510 writeln_docs(w, &field.attrs, "");
511 write!(w, "#[no_mangle]\npub extern \"C\" fn {}_get_{}(this_ptr: &{}) -> ", struct_name, ident, struct_name).unwrap();
512 types.write_c_type(w, &ref_type, Some(&gen_types), true);
513 write!(w, " {{\n\tlet mut inner_val = &mut unsafe {{ &mut *this_ptr.inner }}.{};\n\t", ident).unwrap();
514 let local_var = types.write_to_c_conversion_new_var(w, &syn::Ident::new("inner_val", Span::call_site()), &ref_type, Some(&gen_types), true);
515 if local_var { write!(w, "\n\t").unwrap(); }
516 types.write_to_c_conversion_inline_prefix(w, &ref_type, Some(&gen_types), true);
518 write!(w, "inner_val").unwrap();
520 write!(w, "(*inner_val)").unwrap();
522 types.write_to_c_conversion_inline_suffix(w, &ref_type, Some(&gen_types), true);
523 writeln!(w, "\n}}").unwrap();
526 if types.understood_c_type(&field.ty, Some(&gen_types)) {
527 writeln_docs(w, &field.attrs, "");
528 write!(w, "#[no_mangle]\npub extern \"C\" fn {}_set_{}(this_ptr: &mut {}, mut val: ", struct_name, ident, struct_name).unwrap();
529 types.write_c_type(w, &field.ty, Some(&gen_types), false);
530 write!(w, ") {{\n\t").unwrap();
531 let local_var = types.write_from_c_conversion_new_var(w, &syn::Ident::new("val", Span::call_site()), &field.ty, Some(&gen_types));
532 if local_var { write!(w, "\n\t").unwrap(); }
533 write!(w, "unsafe {{ &mut *this_ptr.inner }}.{} = ", ident).unwrap();
534 types.write_from_c_conversion_prefix(w, &field.ty, Some(&gen_types));
535 write!(w, "val").unwrap();
536 types.write_from_c_conversion_suffix(w, &field.ty, Some(&gen_types));
537 writeln!(w, ";\n}}").unwrap();
538 } else { all_fields_settable = false; }
539 } else { all_fields_settable = false; }
540 } else { all_fields_settable = false; }
543 if all_fields_settable {
544 // Build a constructor!
545 write!(w, "#[must_use]\n#[no_mangle]\npub extern \"C\" fn {}_new(", struct_name).unwrap();
546 for (idx, field) in fields.named.iter().enumerate() {
547 if idx != 0 { write!(w, ", ").unwrap(); }
548 write!(w, "mut {}_arg: ", field.ident.as_ref().unwrap()).unwrap();
549 types.write_c_type(w, &field.ty, Some(&gen_types), false);
551 write!(w, ") -> {} {{\n\t", struct_name).unwrap();
552 for field in fields.named.iter() {
553 let field_name = format!("{}_arg", field.ident.as_ref().unwrap());
554 if types.write_from_c_conversion_new_var(w, &syn::Ident::new(&field_name, Span::call_site()), &field.ty, Some(&gen_types)) {
555 write!(w, "\n\t").unwrap();
558 writeln!(w, "{} {{ inner: Box::into_raw(Box::new(native{} {{", struct_name, s.ident).unwrap();
559 for field in fields.named.iter() {
560 write!(w, "\t\t{}: ", field.ident.as_ref().unwrap()).unwrap();
561 types.write_from_c_conversion_prefix(w, &field.ty, Some(&gen_types));
562 write!(w, "{}_arg", field.ident.as_ref().unwrap()).unwrap();
563 types.write_from_c_conversion_suffix(w, &field.ty, Some(&gen_types));
564 writeln!(w, ",").unwrap();
566 writeln!(w, "\t}})), is_owned: true }}\n}}").unwrap();
570 types.struct_imported(&s.ident, struct_name.clone());
573 /// Prints a relevant conversion for impl *
575 /// For simple impl Struct {}s, this just outputs the wrapper functions as Struct_fn_name() { .. }.
577 /// For impl Trait for Struct{}s, this non-exported generates wrapper functions as
578 /// Trait_Struct_fn_name and a Struct_as_Trait(&struct) -> Trait function which returns a populated
579 /// Trait struct containing a pointer to the passed struct's inner field and the wrapper functions.
581 /// A few non-crate Traits are hard-coded including Default.
582 fn writeln_impl<W: std::io::Write>(w: &mut W, i: &syn::ItemImpl, types: &mut TypeResolver) {
583 if let &syn::Type::Path(ref p) = &*i.self_ty {
584 if p.qself.is_some() { unimplemented!(); }
585 if let Some(ident) = single_ident_generic_path_to_ident(&p.path) {
586 if let Some(resolved_path) = types.maybe_resolve_non_ignored_ident(&ident) {
587 let mut gen_types = GenericTypes::new();
588 if !gen_types.learn_generics(&i.generics, types) {
589 eprintln!("Not implementing anything for impl {} due to not understood generics", ident);
593 if i.defaultness.is_some() || i.unsafety.is_some() { unimplemented!(); }
594 if let Some(trait_path) = i.trait_.as_ref() {
595 if trait_path.0.is_some() { unimplemented!(); }
596 if types.understood_c_path(&trait_path.1) {
597 let full_trait_path = types.resolve_path(&trait_path.1, None);
598 let trait_obj = *types.crate_types.traits.get(&full_trait_path).unwrap();
599 // We learn the associated types maping from the original trait object.
600 // That's great, except that they are unresolved idents, so if we learn
601 // mappings from a trai defined in a different file, we may mis-resolve or
602 // fail to resolve the mapped types.
603 let trait_associated_types = learn_associated_types(trait_obj);
604 let mut impl_associated_types = HashMap::new();
605 for item in i.items.iter() {
607 syn::ImplItem::Type(t) => {
608 if let syn::Type::Path(p) = &t.ty {
609 if let Some(id) = single_ident_generic_path_to_ident(&p.path) {
610 impl_associated_types.insert(&t.ident, id);
618 let export = export_status(&trait_obj.attrs);
620 ExportStatus::Export => {},
621 ExportStatus::NoExport|ExportStatus::TestOnly => return,
623 write!(w, "#[no_mangle]\npub extern \"C\" fn {}_as_{}(this_arg: *const {}) -> crate::{} {{\n", ident, trait_obj.ident, ident, full_trait_path).unwrap();
624 writeln!(w, "\tcrate::{} {{", full_trait_path).unwrap();
625 writeln!(w, "\t\tthis_arg: unsafe {{ (*this_arg).inner as *mut c_void }},").unwrap();
626 writeln!(w, "\t\tfree: None,").unwrap();
628 macro_rules! write_meth {
629 ($m: expr, $trait: expr, $indent: expr) => {
630 let trait_method = $trait.items.iter().filter_map(|item| {
631 if let syn::TraitItem::Method(t_m) = item { Some(t_m) } else { None }
632 }).find(|trait_meth| trait_meth.sig.ident == $m.sig.ident).unwrap();
633 match export_status(&trait_method.attrs) {
634 ExportStatus::Export => {},
635 ExportStatus::NoExport => {
636 write!(w, "{}\t\t//XXX: Need to export {}\n", $indent, $m.sig.ident).unwrap();
639 ExportStatus::TestOnly => continue,
642 let mut printed = false;
643 if let syn::ReturnType::Type(_, rtype) = &$m.sig.output {
644 if let syn::Type::Reference(r) = &**rtype {
645 write!(w, "\n\t\t{}{}: ", $indent, $m.sig.ident).unwrap();
646 types.write_empty_rust_val(Some(&gen_types), w, &*r.elem);
647 writeln!(w, ",\n{}\t\tset_{}: Some({}_{}_set_{}),", $indent, $m.sig.ident, ident, trait_obj.ident, $m.sig.ident).unwrap();
652 write!(w, "{}\t\t{}: {}_{}_{},\n", $indent, $m.sig.ident, ident, trait_obj.ident, $m.sig.ident).unwrap();
656 for item in trait_obj.items.iter() {
658 syn::TraitItem::Method(m) => {
659 write_meth!(m, trait_obj, "");
664 walk_supertraits!(trait_obj, types, (
666 writeln!(w, "\t\tclone: Some({}_clone_void),", ident).unwrap();
669 if s.starts_with("util::") {
670 let supertrait_obj = types.crate_types.traits.get(s).unwrap();
671 writeln!(w, "\t\t{}: crate::{} {{", t, s).unwrap();
672 writeln!(w, "\t\t\tthis_arg: unsafe {{ (*this_arg).inner as *mut c_void }},").unwrap();
673 writeln!(w, "\t\t\tfree: None,").unwrap();
674 for item in supertrait_obj.items.iter() {
676 syn::TraitItem::Method(m) => {
677 write_meth!(m, supertrait_obj, "\t");
682 write!(w, "\t\t}},\n").unwrap();
686 write!(w, "\t}}\n}}\nuse {}::{} as {}TraitImport;\n", types.orig_crate, full_trait_path, trait_obj.ident).unwrap();
688 macro_rules! impl_meth {
689 ($m: expr, $trait: expr, $indent: expr) => {
690 let trait_method = $trait.items.iter().filter_map(|item| {
691 if let syn::TraitItem::Method(t_m) = item { Some(t_m) } else { None }
692 }).find(|trait_meth| trait_meth.sig.ident == $m.sig.ident).unwrap();
693 match export_status(&trait_method.attrs) {
694 ExportStatus::Export => {},
695 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
698 if let syn::ReturnType::Type(_, _) = &$m.sig.output {
699 writeln!(w, "#[must_use]").unwrap();
701 write!(w, "extern \"C\" fn {}_{}_{}(", ident, trait_obj.ident, $m.sig.ident).unwrap();
702 gen_types.push_ctx();
703 assert!(gen_types.learn_generics(&$m.sig.generics, types));
704 write_method_params(w, &$m.sig, &trait_associated_types, "c_void", types, Some(&gen_types), true, true);
705 write!(w, " {{\n\t").unwrap();
706 write_method_var_decl_body(w, &$m.sig, "", types, Some(&gen_types), false);
707 let mut takes_self = false;
708 for inp in $m.sig.inputs.iter() {
709 if let syn::FnArg::Receiver(_) = inp {
714 write!(w, "unsafe {{ &mut *(this_arg as *mut native{}) }}.{}(", ident, $m.sig.ident).unwrap();
716 write!(w, "{}::{}::{}(", types.orig_crate, resolved_path, $m.sig.ident).unwrap();
719 let mut real_type = "".to_string();
720 match &$m.sig.output {
721 syn::ReturnType::Type(_, rtype) => {
722 if let Some(mut remaining_path) = first_seg_self(&*rtype) {
723 if let Some(associated_seg) = get_single_remaining_path_seg(&mut remaining_path) {
724 real_type = format!("{}", impl_associated_types.get(associated_seg).unwrap());
730 write_method_call_params(w, &$m.sig, &trait_associated_types, "", types, Some(&gen_types), &real_type, false);
732 write!(w, "\n}}\n").unwrap();
733 if let syn::ReturnType::Type(_, rtype) = &$m.sig.output {
734 if let syn::Type::Reference(r) = &**rtype {
735 assert_eq!($m.sig.inputs.len(), 1); // Must only take self
736 writeln!(w, "extern \"C\" fn {}_{}_set_{}(trait_self_arg: &{}) {{", ident, trait_obj.ident, $m.sig.ident, trait_obj.ident).unwrap();
737 writeln!(w, "\t// This is a bit race-y in the general case, but for our specific use-cases today, we're safe").unwrap();
738 writeln!(w, "\t// Specifically, we must ensure that the first time we're called it can never be in parallel").unwrap();
739 write!(w, "\tif ").unwrap();
740 types.write_empty_rust_val_check(Some(&gen_types), w, &*r.elem, &format!("trait_self_arg.{}", $m.sig.ident));
741 writeln!(w, " {{").unwrap();
742 writeln!(w, "\t\tunsafe {{ &mut *(trait_self_arg as *const {} as *mut {}) }}.{} = {}_{}_{}(trait_self_arg.this_arg);", trait_obj.ident, trait_obj.ident, $m.sig.ident, ident, trait_obj.ident, $m.sig.ident).unwrap();
743 writeln!(w, "\t}}").unwrap();
744 writeln!(w, "}}").unwrap();
750 for item in i.items.iter() {
752 syn::ImplItem::Method(m) => {
753 impl_meth!(m, trait_obj, "");
755 syn::ImplItem::Type(_) => {},
756 _ => unimplemented!(),
759 walk_supertraits!(trait_obj, types, (
761 if s.starts_with("util::") {
762 writeln!(w, "use {}::{} as native{}Trait;", types.orig_crate, s, t).unwrap();
763 let supertrait_obj = *types.crate_types.traits.get(s).unwrap();
764 for item in supertrait_obj.items.iter() {
766 syn::TraitItem::Method(m) => {
767 impl_meth!(m, supertrait_obj, "\t");
775 write!(w, "\n").unwrap();
776 } else if let Some(trait_ident) = trait_path.1.get_ident() {
777 //XXX: implement for other things like ToString
778 match &format!("{}", trait_ident) as &str {
781 write!(w, "#[must_use]\n#[no_mangle]\npub extern \"C\" fn {}_default() -> {} {{\n", ident, ident).unwrap();
782 write!(w, "\t{} {{ inner: Box::into_raw(Box::new(Default::default())), is_owned: true }}\n", ident).unwrap();
783 write!(w, "}}\n").unwrap();
786 // If we have no generics, try a manual implementation:
787 _ if p.path.get_ident().is_some() => maybe_convert_trait_impl(w, &trait_path.1, &ident, types),
790 } else if p.path.get_ident().is_some() {
791 // If we have no generics, try a manual implementation:
792 maybe_convert_trait_impl(w, &trait_path.1, &ident, types);
795 let declared_type = (*types.get_declared_type(&ident).unwrap()).clone();
796 for item in i.items.iter() {
798 syn::ImplItem::Method(m) => {
799 if let syn::Visibility::Public(_) = m.vis {
800 match export_status(&m.attrs) {
801 ExportStatus::Export => {},
802 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
804 if m.defaultness.is_some() { unimplemented!(); }
805 writeln_docs(w, &m.attrs, "");
806 if let syn::ReturnType::Type(_, _) = &m.sig.output {
807 writeln!(w, "#[must_use]").unwrap();
809 write!(w, "#[no_mangle]\npub extern \"C\" fn {}_{}(", ident, m.sig.ident).unwrap();
810 let ret_type = match &declared_type {
811 DeclType::MirroredEnum => format!("{}", ident),
812 DeclType::StructImported => format!("{}", ident),
813 _ => unimplemented!(),
815 gen_types.push_ctx();
816 assert!(gen_types.learn_generics(&m.sig.generics, types));
817 write_method_params(w, &m.sig, &HashMap::new(), &ret_type, types, Some(&gen_types), false, true);
818 write!(w, " {{\n\t").unwrap();
819 write_method_var_decl_body(w, &m.sig, "", types, Some(&gen_types), false);
820 let mut takes_self = false;
821 let mut takes_mut_self = false;
822 for inp in m.sig.inputs.iter() {
823 if let syn::FnArg::Receiver(r) = inp {
825 if r.mutability.is_some() { takes_mut_self = true; }
829 write!(w, "unsafe {{ &mut (*(this_arg.inner as *mut native{})) }}.{}(", ident, m.sig.ident).unwrap();
830 } else if takes_self {
831 write!(w, "unsafe {{ &*this_arg.inner }}.{}(", m.sig.ident).unwrap();
833 write!(w, "{}::{}::{}(", types.orig_crate, resolved_path, m.sig.ident).unwrap();
835 write_method_call_params(w, &m.sig, &HashMap::new(), "", types, Some(&gen_types), &ret_type, false);
837 writeln!(w, "\n}}\n").unwrap();
845 eprintln!("Not implementing anything for {} due to no-resolve (probably the type isn't pub or its marked not exported)", ident);
851 /// Returns true if the enum will be mapped as an opaue (ie struct with a pointer to the underlying
852 /// type), otherwise it is mapped into a transparent, C-compatible version of itself.
853 fn is_enum_opaque(e: &syn::ItemEnum) -> bool {
854 for var in e.variants.iter() {
855 if let syn::Fields::Unit = var.fields {
856 } else if let syn::Fields::Named(fields) = &var.fields {
857 for field in fields.named.iter() {
858 match export_status(&field.attrs) {
859 ExportStatus::Export|ExportStatus::TestOnly => {},
860 ExportStatus::NoExport => return true,
870 /// Print a mapping of an enum. If all of the enum's fields are C-mapped in some form (or the enum
871 /// is unitary), we generate an equivalent enum with all types replaced with their C mapped
872 /// versions followed by conversion functions which map between the Rust version and the C mapped
874 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) {
875 match export_status(&e.attrs) {
876 ExportStatus::Export => {},
877 ExportStatus::NoExport|ExportStatus::TestOnly => return,
880 if is_enum_opaque(e) {
881 eprintln!("Skipping enum {} as it contains non-unit fields", e.ident);
882 writeln_opaque(w, &e.ident, &format!("{}", e.ident), &e.generics, &e.attrs, types, extra_headers, cpp_headers);
883 types.enum_ignored(&e.ident);
886 writeln_docs(w, &e.attrs, "");
888 if e.generics.lt_token.is_some() {
891 types.mirrored_enum_declared(&e.ident);
893 let mut needs_free = false;
895 writeln!(w, "#[must_use]\n#[derive(Clone)]\n#[repr(C)]\npub enum {} {{", e.ident).unwrap();
896 for var in e.variants.iter() {
897 assert_eq!(export_status(&var.attrs), ExportStatus::Export); // We can't partially-export a mirrored enum
898 writeln_docs(w, &var.attrs, "\t");
899 write!(w, "\t{}", var.ident).unwrap();
900 if let syn::Fields::Named(fields) = &var.fields {
902 writeln!(w, " {{").unwrap();
903 for field in fields.named.iter() {
904 if export_status(&field.attrs) == ExportStatus::TestOnly { continue; }
905 write!(w, "\t\t{}: ", field.ident.as_ref().unwrap()).unwrap();
906 types.write_c_type(w, &field.ty, None, false);
907 writeln!(w, ",").unwrap();
909 write!(w, "\t}}").unwrap();
911 if var.discriminant.is_some() { unimplemented!(); }
912 writeln!(w, ",").unwrap();
914 writeln!(w, "}}\nuse {}::{}::{} as native{};\nimpl {} {{", types.orig_crate, types.module_path, e.ident, e.ident, e.ident).unwrap();
916 macro_rules! write_conv {
917 ($fn_sig: expr, $to_c: expr, $ref: expr) => {
918 writeln!(w, "\t#[allow(unused)]\n\tpub(crate) fn {} {{\n\t\tmatch {} {{", $fn_sig, if $to_c { "native" } else { "self" }).unwrap();
919 for var in e.variants.iter() {
920 write!(w, "\t\t\t{}{}::{} ", if $to_c { "native" } else { "" }, e.ident, var.ident).unwrap();
921 if let syn::Fields::Named(fields) = &var.fields {
922 write!(w, "{{").unwrap();
923 for field in fields.named.iter() {
924 if export_status(&field.attrs) == ExportStatus::TestOnly { continue; }
925 write!(w, "{}{}, ", if $ref { "ref " } else { "mut " }, field.ident.as_ref().unwrap()).unwrap();
927 write!(w, "}} ").unwrap();
929 write!(w, "=>").unwrap();
930 if let syn::Fields::Named(fields) = &var.fields {
931 write!(w, " {{\n\t\t\t\t").unwrap();
932 for field in fields.named.iter() {
933 if export_status(&field.attrs) == ExportStatus::TestOnly { continue; }
934 let mut sink = ::std::io::sink();
935 let mut out: &mut dyn std::io::Write = if $ref { &mut sink } else { w };
936 let new_var = if $to_c {
937 types.write_to_c_conversion_new_var(&mut out, field.ident.as_ref().unwrap(), &field.ty, None, false)
939 types.write_from_c_conversion_new_var(&mut out, field.ident.as_ref().unwrap(), &field.ty, None)
943 write!(w, "let mut {}_nonref = (*{}).clone();\n\t\t\t\t", field.ident.as_ref().unwrap(), field.ident.as_ref().unwrap()).unwrap();
945 let nonref_ident = syn::Ident::new(&format!("{}_nonref", field.ident.as_ref().unwrap()), Span::call_site());
947 types.write_to_c_conversion_new_var(w, &nonref_ident, &field.ty, None, false);
949 types.write_from_c_conversion_new_var(w, &nonref_ident, &field.ty, None);
951 write!(w, "\n\t\t\t\t").unwrap();
954 write!(w, "\n\t\t\t\t").unwrap();
958 } else { write!(w, " ").unwrap(); }
959 write!(w, "{}{}::{}", if $to_c { "" } else { "native" }, e.ident, var.ident).unwrap();
960 if let syn::Fields::Named(fields) = &var.fields {
961 write!(w, " {{").unwrap();
962 for field in fields.named.iter() {
963 if export_status(&field.attrs) == ExportStatus::TestOnly { continue; }
964 write!(w, "\n\t\t\t\t\t{}: ", field.ident.as_ref().unwrap()).unwrap();
966 types.write_to_c_conversion_inline_prefix(w, &field.ty, None, false);
968 types.write_from_c_conversion_prefix(w, &field.ty, None);
971 field.ident.as_ref().unwrap(),
972 if $ref { "_nonref" } else { "" }).unwrap();
974 types.write_to_c_conversion_inline_suffix(w, &field.ty, None, false);
976 types.write_from_c_conversion_suffix(w, &field.ty, None);
978 write!(w, ",").unwrap();
980 writeln!(w, "\n\t\t\t\t}}").unwrap();
981 write!(w, "\t\t\t}}").unwrap();
983 writeln!(w, ",").unwrap();
985 writeln!(w, "\t\t}}\n\t}}").unwrap();
989 write_conv!(format!("to_native(&self) -> native{}", e.ident), false, true);
990 write_conv!(format!("into_native(self) -> native{}", e.ident), false, false);
991 write_conv!(format!("from_native(native: &native{}) -> Self", e.ident), true, true);
992 write_conv!(format!("native_into(native: native{}) -> Self", e.ident), true, false);
993 writeln!(w, "}}").unwrap();
996 writeln!(w, "#[no_mangle]\npub extern \"C\" fn {}_free(this_ptr: {}) {{ }}", e.ident, e.ident).unwrap();
998 writeln!(w, "#[no_mangle]").unwrap();
999 writeln!(w, "pub extern \"C\" fn {}_clone(orig: &{}) -> {} {{", e.ident, e.ident, e.ident).unwrap();
1000 writeln!(w, "\torig.clone()").unwrap();
1001 writeln!(w, "}}").unwrap();
1002 write_cpp_wrapper(cpp_headers, &format!("{}", e.ident), needs_free);
1005 fn writeln_fn<'a, 'b, W: std::io::Write>(w: &mut W, f: &'a syn::ItemFn, types: &mut TypeResolver<'b, 'a>) {
1006 match export_status(&f.attrs) {
1007 ExportStatus::Export => {},
1008 ExportStatus::NoExport|ExportStatus::TestOnly => return,
1010 writeln_docs(w, &f.attrs, "");
1012 let mut gen_types = GenericTypes::new();
1013 if !gen_types.learn_generics(&f.sig.generics, types) { return; }
1015 write!(w, "#[no_mangle]\npub extern \"C\" fn {}(", f.sig.ident).unwrap();
1016 write_method_params(w, &f.sig, &HashMap::new(), "", types, Some(&gen_types), false, true);
1017 write!(w, " {{\n\t").unwrap();
1018 write_method_var_decl_body(w, &f.sig, "", types, Some(&gen_types), false);
1019 write!(w, "{}::{}::{}(", types.orig_crate, types.module_path, f.sig.ident).unwrap();
1020 write_method_call_params(w, &f.sig, &HashMap::new(), "", types, Some(&gen_types), "", false);
1021 writeln!(w, "\n}}\n").unwrap();
1024 // ********************************
1025 // *** File/Crate Walking Logic ***
1026 // ********************************
1028 /// Simple utility to walk the modules in a crate - iterating over the modules (with file paths) in
1030 struct FileIter<'a, I: Iterator<Item = &'a syn::Item>> {
1036 impl<'a, I: Iterator<Item = &'a syn::Item>> Iterator for FileIter<'a, I> {
1037 type Item = (String, String, &'a syn::ItemMod);
1038 fn next(&mut self) -> std::option::Option<<Self as std::iter::Iterator>::Item> {
1040 match self.item_iter.next() {
1041 Some(syn::Item::Mod(m)) => {
1042 if let syn::Visibility::Public(_) = m.vis {
1043 match export_status(&m.attrs) {
1044 ExportStatus::Export => {},
1045 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1048 let f_path = format!("{}/{}.rs", (self.path.as_ref() as &Path).parent().unwrap().display(), m.ident);
1049 let new_mod = if self.module.is_empty() { format!("{}", m.ident) } else { format!("{}::{}", self.module, m.ident) };
1050 if let Ok(_) = File::open(&format!("{}/{}", self.in_dir, f_path)) {
1051 return Some((f_path, new_mod, m));
1054 format!("{}/{}/mod.rs", (self.path.as_ref() as &Path).parent().unwrap().display(), m.ident),
1060 None => return None,
1065 fn file_iter<'a>(file: &'a syn::File, in_dir: &'a str, path: &'a str, module: &'a str) ->
1066 impl Iterator<Item = (String, String, &'a syn::ItemMod)> + 'a {
1067 FileIter { in_dir, path, module, item_iter: file.items.iter() }
1070 /// A struct containing the syn::File AST for each file in the crate.
1071 struct FullLibraryAST {
1072 files: HashMap<String, syn::File>,
1075 /// Do the Real Work of mapping an original file to C-callable wrappers. Creates a new file at
1076 /// `out_path` and fills it with wrapper structs/functions to allow calling the things in the AST
1077 /// at `module` from C.
1078 fn convert_file<'a, 'b>(libast: &'a FullLibraryAST, crate_types: &mut CrateTypes<'a>, in_dir: &str, out_dir: &str, path: &str, orig_crate: &str, module: &str, header_file: &mut File, cpp_header_file: &mut File) {
1079 let syntax = if let Some(ast) = libast.files.get(module) { ast } else { return };
1081 assert!(syntax.shebang.is_none()); // Not sure what this is, hope we dont have one
1083 let new_file_path = format!("{}/{}", out_dir, path);
1084 let _ = std::fs::create_dir((&new_file_path.as_ref() as &std::path::Path).parent().unwrap());
1085 let mut out = std::fs::OpenOptions::new().write(true).create(true).truncate(true)
1086 .open(new_file_path).expect("Unable to open new src file");
1088 assert_eq!(export_status(&syntax.attrs), ExportStatus::Export);
1089 writeln_docs(&mut out, &syntax.attrs, "");
1091 if path.ends_with("/lib.rs") {
1092 // Special-case the top-level lib.rs with various lint allows and a pointer to the c_types
1093 // and bitcoin hand-written modules.
1094 writeln!(out, "#![allow(unknown_lints)]").unwrap();
1095 writeln!(out, "#![allow(non_camel_case_types)]").unwrap();
1096 writeln!(out, "#![allow(non_snake_case)]").unwrap();
1097 writeln!(out, "#![allow(unused_imports)]").unwrap();
1098 writeln!(out, "#![allow(unused_variables)]").unwrap();
1099 writeln!(out, "#![allow(unused_mut)]").unwrap();
1100 writeln!(out, "#![allow(unused_parens)]").unwrap();
1101 writeln!(out, "#![allow(unused_unsafe)]").unwrap();
1102 writeln!(out, "#![allow(unused_braces)]").unwrap();
1103 writeln!(out, "mod c_types;").unwrap();
1104 writeln!(out, "mod bitcoin;").unwrap();
1106 writeln!(out, "\nuse std::ffi::c_void;\nuse bitcoin::hashes::Hash;\nuse crate::c_types::*;\n").unwrap();
1109 for (path, new_mod, m) in file_iter(&syntax, in_dir, path, &module) {
1110 writeln_docs(&mut out, &m.attrs, "");
1111 writeln!(out, "pub mod {};", m.ident).unwrap();
1112 convert_file(libast, crate_types, in_dir, out_dir, &path,
1113 orig_crate, &new_mod, header_file, cpp_header_file);
1116 eprintln!("Converting {} entries...", path);
1118 let mut type_resolver = TypeResolver::new(orig_crate, module, crate_types);
1120 for item in syntax.items.iter() {
1122 syn::Item::Use(u) => type_resolver.process_use(&mut out, &u),
1123 syn::Item::Static(_) => {},
1124 syn::Item::Enum(e) => {
1125 if let syn::Visibility::Public(_) = e.vis {
1126 writeln_enum(&mut out, &e, &mut type_resolver, header_file, cpp_header_file);
1129 syn::Item::Impl(i) => {
1130 writeln_impl(&mut out, &i, &mut type_resolver);
1132 syn::Item::Struct(s) => {
1133 if let syn::Visibility::Public(_) = s.vis {
1134 writeln_struct(&mut out, &s, &mut type_resolver, header_file, cpp_header_file);
1137 syn::Item::Trait(t) => {
1138 if let syn::Visibility::Public(_) = t.vis {
1139 writeln_trait(&mut out, &t, &mut type_resolver, header_file, cpp_header_file);
1142 syn::Item::Mod(_) => {}, // We don't have to do anything - the top loop handles these.
1143 syn::Item::Const(c) => {
1144 // Re-export any primitive-type constants.
1145 if let syn::Visibility::Public(_) = c.vis {
1146 if let syn::Type::Path(p) = &*c.ty {
1147 let resolved_path = type_resolver.resolve_path(&p.path, None);
1148 if type_resolver.is_primitive(&resolved_path) {
1149 writeln!(out, "\n#[no_mangle]").unwrap();
1150 writeln!(out, "pub static {}: {} = {}::{}::{};", c.ident, resolved_path, orig_crate, module, c.ident).unwrap();
1155 syn::Item::Type(t) => {
1156 if let syn::Visibility::Public(_) = t.vis {
1157 match export_status(&t.attrs) {
1158 ExportStatus::Export => {},
1159 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1162 let mut process_alias = true;
1163 for tok in t.generics.params.iter() {
1164 if let syn::GenericParam::Lifetime(_) = tok {}
1165 else { process_alias = false; }
1169 syn::Type::Path(_) =>
1170 writeln_opaque(&mut out, &t.ident, &format!("{}", t.ident), &t.generics, &t.attrs, &type_resolver, header_file, cpp_header_file),
1176 syn::Item::Fn(f) => {
1177 if let syn::Visibility::Public(_) = f.vis {
1178 writeln_fn(&mut out, &f, &mut type_resolver);
1181 syn::Item::Macro(m) => {
1182 if m.ident.is_none() { // If its not a macro definition
1183 convert_macro(&mut out, &m.mac.path, &m.mac.tokens, &type_resolver);
1186 syn::Item::Verbatim(_) => {},
1187 syn::Item::ExternCrate(_) => {},
1188 _ => unimplemented!(),
1192 out.flush().unwrap();
1195 /// Load the AST for each file in the crate, filling the FullLibraryAST object
1196 fn load_ast(in_dir: &str, path: &str, module: String, ast_storage: &mut FullLibraryAST) {
1197 eprintln!("Loading {}{}...", in_dir, path);
1199 let mut file = File::open(format!("{}/{}", in_dir, path)).expect("Unable to open file");
1200 let mut src = String::new();
1201 file.read_to_string(&mut src).expect("Unable to read file");
1202 let syntax = syn::parse_file(&src).expect("Unable to parse file");
1204 assert_eq!(export_status(&syntax.attrs), ExportStatus::Export);
1206 for (path, new_mod, _) in file_iter(&syntax, in_dir, path, &module) {
1207 load_ast(in_dir, &path, new_mod, ast_storage);
1209 ast_storage.files.insert(module, syntax);
1212 /// Insert ident -> absolute Path resolutions into imports from the given UseTree and path-prefix.
1213 fn process_use_intern<'a>(u: &'a syn::UseTree, mut path: syn::punctuated::Punctuated<syn::PathSegment, syn::token::Colon2>, imports: &mut HashMap<&'a syn::Ident, syn::Path>) {
1215 syn::UseTree::Path(p) => {
1216 path.push(syn::PathSegment { ident: p.ident.clone(), arguments: syn::PathArguments::None });
1217 process_use_intern(&p.tree, path, imports);
1219 syn::UseTree::Name(n) => {
1220 path.push(syn::PathSegment { ident: n.ident.clone(), arguments: syn::PathArguments::None });
1221 imports.insert(&n.ident, syn::Path { leading_colon: Some(syn::Token![::](Span::call_site())), segments: path });
1223 syn::UseTree::Group(g) => {
1224 for i in g.items.iter() {
1225 process_use_intern(i, path.clone(), imports);
1232 /// Map all the Paths in a Type into absolute paths given a set of imports (generated via process_use_intern)
1233 fn resolve_imported_refs(imports: &HashMap<&syn::Ident, syn::Path>, mut ty: syn::Type) -> syn::Type {
1235 syn::Type::Path(p) => {
1236 if let Some(ident) = p.path.get_ident() {
1237 if let Some(newpath) = imports.get(ident) {
1238 p.path = newpath.clone();
1240 } else { unimplemented!(); }
1242 syn::Type::Reference(r) => {
1243 r.elem = Box::new(resolve_imported_refs(imports, (*r.elem).clone()));
1245 syn::Type::Slice(s) => {
1246 s.elem = Box::new(resolve_imported_refs(imports, (*s.elem).clone()));
1248 syn::Type::Tuple(t) => {
1249 for e in t.elems.iter_mut() {
1250 *e = resolve_imported_refs(imports, e.clone());
1253 _ => unimplemented!(),
1258 /// Walk the FullLibraryAST, deciding how things will be mapped and adding tracking to CrateTypes.
1259 fn walk_ast<'a>(in_dir: &str, path: &str, module: String, ast_storage: &'a FullLibraryAST, crate_types: &mut CrateTypes<'a>) {
1260 let syntax = if let Some(ast) = ast_storage.files.get(&module) { ast } else { return };
1261 assert_eq!(export_status(&syntax.attrs), ExportStatus::Export);
1263 for (path, new_mod, _) in file_iter(&syntax, in_dir, path, &module) {
1264 walk_ast(in_dir, &path, new_mod, ast_storage, crate_types);
1267 let mut import_maps = HashMap::new();
1269 for item in syntax.items.iter() {
1271 syn::Item::Use(u) => {
1272 process_use_intern(&u.tree, syn::punctuated::Punctuated::new(), &mut import_maps);
1274 syn::Item::Struct(s) => {
1275 if let syn::Visibility::Public(_) = s.vis {
1276 match export_status(&s.attrs) {
1277 ExportStatus::Export => {},
1278 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1280 let struct_path = format!("{}::{}", module, s.ident);
1281 crate_types.opaques.insert(struct_path, &s.ident);
1284 syn::Item::Trait(t) => {
1285 if let syn::Visibility::Public(_) = t.vis {
1286 match export_status(&t.attrs) {
1287 ExportStatus::Export => {},
1288 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1290 let trait_path = format!("{}::{}", module, t.ident);
1291 crate_types.traits.insert(trait_path, &t);
1294 syn::Item::Type(t) => {
1295 if let syn::Visibility::Public(_) = t.vis {
1296 match export_status(&t.attrs) {
1297 ExportStatus::Export => {},
1298 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1300 let type_path = format!("{}::{}", module, t.ident);
1301 let mut process_alias = true;
1302 for tok in t.generics.params.iter() {
1303 if let syn::GenericParam::Lifetime(_) = tok {}
1304 else { process_alias = false; }
1308 syn::Type::Path(_) => {
1309 // If its a path with no generics, assume we don't map the aliased type and map it opaque
1310 crate_types.opaques.insert(type_path, &t.ident);
1313 crate_types.type_aliases.insert(type_path, resolve_imported_refs(&import_maps, (*t.ty).clone()));
1319 syn::Item::Enum(e) if is_enum_opaque(e) => {
1320 if let syn::Visibility::Public(_) = e.vis {
1321 match export_status(&e.attrs) {
1322 ExportStatus::Export => {},
1323 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1325 let enum_path = format!("{}::{}", module, e.ident);
1326 crate_types.opaques.insert(enum_path, &e.ident);
1329 syn::Item::Enum(e) => {
1330 if let syn::Visibility::Public(_) = e.vis {
1331 match export_status(&e.attrs) {
1332 ExportStatus::Export => {},
1333 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1335 let enum_path = format!("{}::{}", module, e.ident);
1336 crate_types.mirrored_enums.insert(enum_path, &e);
1345 let args: Vec<String> = env::args().collect();
1346 if args.len() != 7 {
1347 eprintln!("Usage: source/dir target/dir source_crate_name derived_templates.rs extra/includes.h extra/cpp/includes.hpp");
1351 let mut derived_templates = std::fs::OpenOptions::new().write(true).create(true).truncate(true)
1352 .open(&args[4]).expect("Unable to open new header file");
1353 let mut header_file = std::fs::OpenOptions::new().write(true).create(true).truncate(true)
1354 .open(&args[5]).expect("Unable to open new header file");
1355 let mut cpp_header_file = std::fs::OpenOptions::new().write(true).create(true).truncate(true)
1356 .open(&args[6]).expect("Unable to open new header file");
1358 writeln!(header_file, "#if defined(__GNUC__)\n#define MUST_USE_STRUCT __attribute__((warn_unused))").unwrap();
1359 writeln!(header_file, "#else\n#define MUST_USE_STRUCT\n#endif").unwrap();
1360 writeln!(header_file, "#if defined(__GNUC__)\n#define MUST_USE_RES __attribute__((warn_unused_result))").unwrap();
1361 writeln!(header_file, "#else\n#define MUST_USE_RES\n#endif").unwrap();
1362 writeln!(cpp_header_file, "#include <string.h>\nnamespace LDK {{").unwrap();
1364 // First parse the full crate's ASTs, caching them so that we can hold references to the AST
1365 // objects in other datastructures:
1366 let mut libast = FullLibraryAST { files: HashMap::new() };
1367 load_ast(&args[1], "/lib.rs", "".to_string(), &mut libast);
1369 // ...then walk the ASTs tracking what types we will map, and how, so that we can resolve them
1370 // when parsing other file ASTs...
1371 let mut libtypes = CrateTypes { traits: HashMap::new(), opaques: HashMap::new(), mirrored_enums: HashMap::new(),
1372 type_aliases: HashMap::new(), templates_defined: HashMap::default(), template_file: &mut derived_templates };
1373 walk_ast(&args[1], "/lib.rs", "".to_string(), &libast, &mut libtypes);
1375 // ... finally, do the actual file conversion/mapping, writing out types as we go.
1376 convert_file(&libast, &mut libtypes, &args[1], &args[2], "/lib.rs", &args[3], "", &mut header_file, &mut cpp_header_file);
1378 // For container templates which we created while walking the crate, make sure we add C++
1379 // mapped types so that C++ users can utilize the auto-destructors available.
1380 for (ty, has_destructor) in libtypes.templates_defined.iter() {
1381 write_cpp_wrapper(&mut cpp_header_file, ty, *has_destructor);
1383 writeln!(cpp_header_file, "}}").unwrap();
1385 header_file.flush().unwrap();
1386 cpp_header_file.flush().unwrap();
1387 derived_templates.flush().unwrap();