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 /// Write out the impl block for a defined trait struct which has a supertrait
84 fn do_write_impl_trait<W: std::io::Write>(w: &mut W, trait_path: &str, trait_name: &syn::Ident, for_obj: &str) {
86 "util::events::MessageSendEventsProvider" => {
87 writeln!(w, "impl lightning::{} for {} {{", trait_path, for_obj).unwrap();
88 writeln!(w, "\tfn get_and_clear_pending_msg_events(&self) -> Vec<lightning::util::events::MessageSendEvent> {{").unwrap();
89 writeln!(w, "\t\t<crate::{} as lightning::{}>::get_and_clear_pending_msg_events(&self.{})", trait_path, trait_path, trait_name).unwrap();
90 writeln!(w, "\t}}\n}}").unwrap();
96 // *******************************
97 // *** Per-Type Printing Logic ***
98 // *******************************
100 macro_rules! walk_supertraits { ($t: expr, $types: expr, ($( $pat: pat => $e: expr),*) ) => { {
101 if $t.colon_token.is_some() {
102 for st in $t.supertraits.iter() {
104 syn::TypeParamBound::Trait(supertrait) => {
105 if supertrait.paren_token.is_some() || supertrait.lifetimes.is_some() {
108 // First try to resolve path to find in-crate traits, but if that doesn't work
109 // assume its a prelude trait (eg Clone, etc) and just use the single ident.
110 if let Some(path) = $types.maybe_resolve_path(&supertrait.path, None) {
111 match (&path as &str, &supertrait.path.segments.iter().last().unwrap().ident) {
114 } else if let Some(ident) = supertrait.path.get_ident() {
115 match (&format!("{}", ident) as &str, &ident) {
119 panic!("Supertrait unresolvable and not single-ident");
122 syn::TypeParamBound::Lifetime(_) => unimplemented!(),
128 /// Prints a C-mapped trait object containing a void pointer and a jump table for each function in
129 /// the original trait.
130 /// Implements the native Rust trait and relevant parent traits for the new C-mapped trait.
132 /// Finally, implements Deref<MappedTrait> for MappedTrait which allows its use in types which need
133 /// a concrete Deref to the Rust trait.
134 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) {
135 let trait_name = format!("{}", t.ident);
136 match export_status(&t.attrs) {
137 ExportStatus::Export => {},
138 ExportStatus::NoExport|ExportStatus::TestOnly => return,
140 writeln_docs(w, &t.attrs, "");
142 let mut gen_types = GenericTypes::new();
143 assert!(gen_types.learn_generics(&t.generics, types));
144 gen_types.learn_associated_types(&t, types);
146 writeln!(w, "#[repr(C)]\npub struct {} {{", trait_name).unwrap();
147 writeln!(w, "\tpub this_arg: *mut c_void,").unwrap();
148 let mut generated_fields = Vec::new(); // Every field's name except this_arg, used in Clone generation
149 for item in t.items.iter() {
151 &syn::TraitItem::Method(ref m) => {
152 match export_status(&m.attrs) {
153 ExportStatus::NoExport => {
154 // NoExport in this context means we'll hit an unimplemented!() at runtime,
158 ExportStatus::Export => {},
159 ExportStatus::TestOnly => continue,
161 if m.default.is_some() { unimplemented!(); }
163 gen_types.push_ctx();
164 assert!(gen_types.learn_generics(&m.sig.generics, types));
166 writeln_docs(w, &m.attrs, "\t");
168 if let syn::ReturnType::Type(_, rtype) = &m.sig.output {
169 if let syn::Type::Reference(r) = &**rtype {
170 // We have to do quite a dance for trait functions which return references
171 // - they ultimately require us to have a native Rust object stored inside
172 // our concrete trait to return a reference to. However, users may wish to
173 // update the value to be returned each time the function is called (or, to
174 // make C copies of Rust impls equivalent, we have to be able to).
176 // Thus, we store a copy of the C-mapped type (which is just a pointer to
177 // the Rust type and a flag to indicate whether deallocation needs to
178 // happen) as well as provide an Option<>al function pointer which is
179 // called when the trait method is called which allows updating on the fly.
180 write!(w, "\tpub {}: ", m.sig.ident).unwrap();
181 generated_fields.push(format!("{}", m.sig.ident));
182 types.write_c_type(w, &*r.elem, Some(&gen_types), false);
183 writeln!(w, ",").unwrap();
184 writeln!(w, "\t/// Fill in the {} field as a reference to it will be given to Rust after this returns", m.sig.ident).unwrap();
185 writeln!(w, "\t/// Note that this takes a pointer to this object, not the this_ptr like other methods do").unwrap();
186 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();
187 writeln!(w, "\tpub set_{}: Option<extern \"C\" fn(&{})>,", m.sig.ident, trait_name).unwrap();
188 generated_fields.push(format!("set_{}", m.sig.ident));
189 // Note that cbindgen will now generate
190 // typedef struct Thing {..., set_thing: (const Thing*), ...} Thing;
191 // which does not compile since Thing is not defined before it is used.
192 writeln!(extra_headers, "struct LDK{};", trait_name).unwrap();
193 writeln!(extra_headers, "typedef struct LDK{} LDK{};", trait_name, trait_name).unwrap();
197 // Sadly, this currently doesn't do what we want, but it should be easy to get
198 // cbindgen to support it. See https://github.com/eqrion/cbindgen/issues/531
199 writeln!(w, "\t#[must_use]").unwrap();
202 write!(w, "\tpub {}: extern \"C\" fn (", m.sig.ident).unwrap();
203 generated_fields.push(format!("{}", m.sig.ident));
204 write_method_params(w, &m.sig, "c_void", types, Some(&gen_types), true, false);
205 writeln!(w, ",").unwrap();
209 &syn::TraitItem::Type(_) => {},
210 _ => unimplemented!(),
213 // Add functions which may be required for supertrait implementations.
214 walk_supertraits!(t, types, (
216 writeln!(w, "\tpub clone: Option<extern \"C\" fn (this_arg: *const c_void) -> *mut c_void>,").unwrap();
217 generated_fields.push("clone".to_owned());
219 ("std::cmp::Eq", _) => {
220 writeln!(w, "\tpub eq: extern \"C\" fn (this_arg: *const c_void, other_arg: &{}) -> bool,", trait_name).unwrap();
221 writeln!(extra_headers, "typedef struct LDK{} LDK{};", trait_name, trait_name).unwrap();
222 generated_fields.push("eq".to_owned());
224 ("std::hash::Hash", _) => {
225 writeln!(w, "\tpub hash: extern \"C\" fn (this_arg: *const c_void) -> u64,").unwrap();
226 generated_fields.push("hash".to_owned());
228 ("Send", _) => {}, ("Sync", _) => {},
230 // For in-crate supertraits, just store a C-mapped copy of the supertrait as a member.
231 if types.crate_types.traits.get(s).is_none() { unimplemented!(); }
232 writeln!(w, "\tpub {}: crate::{},", i, s).unwrap();
233 generated_fields.push(format!("{}", i));
236 writeln!(w, "\tpub free: Option<extern \"C\" fn(this_arg: *mut c_void)>,").unwrap();
237 generated_fields.push("free".to_owned());
238 writeln!(w, "}}").unwrap();
239 // Implement supertraits for the C-mapped struct.
240 walk_supertraits!(t, types, (
241 ("Send", _) => writeln!(w, "unsafe impl Send for {} {{}}", trait_name).unwrap(),
242 ("Sync", _) => writeln!(w, "unsafe impl Sync for {} {{}}", trait_name).unwrap(),
243 ("std::cmp::Eq", _) => {
244 writeln!(w, "impl std::cmp::Eq for {} {{}}", trait_name).unwrap();
245 writeln!(w, "impl std::cmp::PartialEq for {} {{", trait_name).unwrap();
246 writeln!(w, "\tfn eq(&self, o: &Self) -> bool {{ (self.eq)(self.this_arg, o) }}\n}}").unwrap();
248 ("std::hash::Hash", _) => {
249 writeln!(w, "impl std::hash::Hash for {} {{", trait_name).unwrap();
250 writeln!(w, "\tfn hash<H: std::hash::Hasher>(&self, hasher: &mut H) {{ hasher.write_u64((self.hash)(self.this_arg)) }}\n}}").unwrap();
253 writeln!(w, "#[no_mangle]").unwrap();
254 writeln!(w, "pub extern \"C\" fn {}_clone(orig: &{}) -> {} {{", trait_name, trait_name, trait_name).unwrap();
255 writeln!(w, "\t{} {{", trait_name).unwrap();
256 writeln!(w, "\t\tthis_arg: if let Some(f) = orig.clone {{ (f)(orig.this_arg) }} else {{ orig.this_arg }},").unwrap();
257 for field in generated_fields.iter() {
258 writeln!(w, "\t\t{}: orig.{}.clone(),", field, field).unwrap();
260 writeln!(w, "\t}}\n}}").unwrap();
261 writeln!(w, "impl Clone for {} {{", trait_name).unwrap();
262 writeln!(w, "\tfn clone(&self) -> Self {{").unwrap();
263 writeln!(w, "\t\t{}_clone(self)", trait_name).unwrap();
264 writeln!(w, "\t}}\n}}").unwrap();
267 do_write_impl_trait(w, s, i, &trait_name);
271 // Finally, implement the original Rust trait for the newly created mapped trait.
272 writeln!(w, "\nuse {}::{}::{} as rust{};", types.orig_crate, types.module_path, t.ident, trait_name).unwrap();
273 write!(w, "impl rust{}", t.ident).unwrap();
274 maybe_write_generics(w, &t.generics, types, false);
275 writeln!(w, " for {} {{", trait_name).unwrap();
276 for item in t.items.iter() {
278 syn::TraitItem::Method(m) => {
279 if let ExportStatus::TestOnly = export_status(&m.attrs) { continue; }
280 if m.default.is_some() { unimplemented!(); }
281 if m.sig.constness.is_some() || m.sig.asyncness.is_some() || m.sig.unsafety.is_some() ||
282 m.sig.abi.is_some() || m.sig.variadic.is_some() {
285 gen_types.push_ctx();
286 assert!(gen_types.learn_generics(&m.sig.generics, types));
287 write!(w, "\tfn {}", m.sig.ident).unwrap();
288 types.write_rust_generic_param(w, Some(&gen_types), m.sig.generics.params.iter());
289 write!(w, "(").unwrap();
290 for inp in m.sig.inputs.iter() {
292 syn::FnArg::Receiver(recv) => {
293 if !recv.attrs.is_empty() || recv.reference.is_none() { unimplemented!(); }
294 write!(w, "&").unwrap();
295 if let Some(lft) = &recv.reference.as_ref().unwrap().1 {
296 write!(w, "'{} ", lft.ident).unwrap();
298 if recv.mutability.is_some() {
299 write!(w, "mut self").unwrap();
301 write!(w, "self").unwrap();
304 syn::FnArg::Typed(arg) => {
305 if !arg.attrs.is_empty() { unimplemented!(); }
307 syn::Pat::Ident(ident) => {
308 if !ident.attrs.is_empty() || ident.by_ref.is_some() ||
309 ident.mutability.is_some() || ident.subpat.is_some() {
312 write!(w, ", {}{}: ", if types.skip_arg(&*arg.ty, Some(&gen_types)) { "_" } else { "" }, ident.ident).unwrap();
314 _ => unimplemented!(),
316 types.write_rust_type(w, Some(&gen_types), &*arg.ty);
320 write!(w, ")").unwrap();
321 match &m.sig.output {
322 syn::ReturnType::Type(_, rtype) => {
323 write!(w, " -> ").unwrap();
324 types.write_rust_type(w, Some(&gen_types), &*rtype)
328 write!(w, " {{\n\t\t").unwrap();
329 match export_status(&m.attrs) {
330 ExportStatus::NoExport => {
335 if let syn::ReturnType::Type(_, rtype) = &m.sig.output {
336 if let syn::Type::Reference(r) = &**rtype {
337 assert_eq!(m.sig.inputs.len(), 1); // Must only take self!
338 writeln!(w, "if let Some(f) = self.set_{} {{", m.sig.ident).unwrap();
339 writeln!(w, "\t\t\t(f)(self);").unwrap();
340 write!(w, "\t\t}}\n\t\t").unwrap();
341 types.write_from_c_conversion_to_ref_prefix(w, &*r.elem, Some(&gen_types));
342 write!(w, "self.{}", m.sig.ident).unwrap();
343 types.write_from_c_conversion_to_ref_suffix(w, &*r.elem, Some(&gen_types));
344 writeln!(w, "\n\t}}").unwrap();
349 write_method_var_decl_body(w, &m.sig, "\t", types, Some(&gen_types), true);
350 write!(w, "(self.{})(", m.sig.ident).unwrap();
351 write_method_call_params(w, &m.sig, "\t", types, Some(&gen_types), "", true);
353 writeln!(w, "\n\t}}").unwrap();
356 &syn::TraitItem::Type(ref t) => {
357 if t.default.is_some() || t.generics.lt_token.is_some() { unimplemented!(); }
358 let mut bounds_iter = t.bounds.iter();
359 match bounds_iter.next().unwrap() {
360 syn::TypeParamBound::Trait(tr) => {
361 writeln!(w, "\ttype {} = crate::{};", t.ident, types.resolve_path(&tr.path, Some(&gen_types))).unwrap();
363 _ => unimplemented!(),
365 if bounds_iter.next().is_some() { unimplemented!(); }
367 _ => unimplemented!(),
370 writeln!(w, "}}\n").unwrap();
371 writeln!(w, "// We're essentially a pointer already, or at least a set of pointers, so allow us to be used").unwrap();
372 writeln!(w, "// directly as a Deref trait in higher-level structs:").unwrap();
373 writeln!(w, "impl std::ops::Deref for {} {{\n\ttype Target = Self;", trait_name).unwrap();
374 writeln!(w, "\tfn deref(&self) -> &Self {{\n\t\tself\n\t}}\n}}").unwrap();
376 writeln!(w, "/// Calls the free function if one is set").unwrap();
377 writeln!(w, "#[no_mangle]\npub extern \"C\" fn {}_free(this_ptr: {}) {{ }}", trait_name, trait_name).unwrap();
378 writeln!(w, "impl Drop for {} {{", trait_name).unwrap();
379 writeln!(w, "\tfn drop(&mut self) {{").unwrap();
380 writeln!(w, "\t\tif let Some(f) = self.free {{").unwrap();
381 writeln!(w, "\t\t\tf(self.this_arg);").unwrap();
382 writeln!(w, "\t\t}}\n\t}}\n}}").unwrap();
384 write_cpp_wrapper(cpp_headers, &trait_name, true);
385 types.trait_declared(&t.ident, t);
388 /// Write out a simple "opaque" type (eg structs) which contain a pointer to the native Rust type
389 /// and a flag to indicate whether Drop'ing the mapped struct drops the underlying Rust type.
391 /// Also writes out a _free function and a C++ wrapper which handles calling _free.
392 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) {
393 // If we directly read the original type by its original name, cbindgen hits
394 // https://github.com/eqrion/cbindgen/issues/286 Thus, instead, we import it as a temporary
395 // name and then reference it by that name, which works around the issue.
396 write!(w, "\nuse {}::{}::{} as native{}Import;\ntype native{} = native{}Import", types.orig_crate, types.module_path, ident, ident, ident, ident).unwrap();
397 maybe_write_generics(w, &generics, &types, true);
398 writeln!(w, ";\n").unwrap();
399 writeln!(extra_headers, "struct native{}Opaque;\ntypedef struct native{}Opaque LDKnative{};", ident, ident, ident).unwrap();
400 writeln_docs(w, &attrs, "");
401 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();
402 writeln!(w, "\t/// the Rust equivalent takes an Option, it may be set to null to indicate None.").unwrap();
403 writeln!(w, "\tpub inner: *mut native{},\n\tpub is_owned: bool,\n}}\n", ident).unwrap();
404 writeln!(w, "impl Drop for {} {{\n\tfn drop(&mut self) {{", struct_name).unwrap();
405 writeln!(w, "\t\tif self.is_owned && !self.inner.is_null() {{").unwrap();
406 writeln!(w, "\t\t\tlet _ = unsafe {{ Box::from_raw(self.inner) }};\n\t\t}}\n\t}}\n}}").unwrap();
407 writeln!(w, "#[no_mangle]\npub extern \"C\" fn {}_free(this_ptr: {}) {{ }}", struct_name, struct_name).unwrap();
408 writeln!(w, "#[allow(unused)]").unwrap();
409 writeln!(w, "/// Used only if an object of this type is returned as a trait impl by a method").unwrap();
410 writeln!(w, "extern \"C\" fn {}_free_void(this_ptr: *mut c_void) {{", struct_name).unwrap();
411 writeln!(w, "\tunsafe {{ let _ = Box::from_raw(this_ptr as *mut native{}); }}\n}}", struct_name).unwrap();
412 writeln!(w, "#[allow(unused)]").unwrap();
413 writeln!(w, "/// When moving out of the pointer, we have to ensure we aren't a reference, this makes that easy").unwrap();
414 writeln!(w, "impl {} {{", struct_name).unwrap();
415 writeln!(w, "\tpub(crate) fn take_ptr(mut self) -> *mut native{} {{", struct_name).unwrap();
416 writeln!(w, "\t\tassert!(self.is_owned);").unwrap();
417 writeln!(w, "\t\tlet ret = self.inner;").unwrap();
418 writeln!(w, "\t\tself.inner = std::ptr::null_mut();").unwrap();
419 writeln!(w, "\t\tret").unwrap();
420 writeln!(w, "\t}}\n}}").unwrap();
422 'attr_loop: for attr in attrs.iter() {
423 let tokens_clone = attr.tokens.clone();
424 let mut token_iter = tokens_clone.into_iter();
425 if let Some(token) = token_iter.next() {
427 TokenTree::Group(g) => {
428 if format!("{}", single_ident_generic_path_to_ident(&attr.path).unwrap()) == "derive" {
429 for id in g.stream().into_iter() {
430 if let TokenTree::Ident(i) = id {
432 writeln!(w, "impl Clone for {} {{", struct_name).unwrap();
433 writeln!(w, "\tfn clone(&self) -> Self {{").unwrap();
434 writeln!(w, "\t\tSelf {{").unwrap();
435 writeln!(w, "\t\t\tinner: Box::into_raw(Box::new(unsafe {{ &*self.inner }}.clone())),").unwrap();
436 writeln!(w, "\t\t\tis_owned: true,").unwrap();
437 writeln!(w, "\t\t}}\n\t}}\n}}").unwrap();
438 writeln!(w, "#[allow(unused)]").unwrap();
439 writeln!(w, "/// Used only if an object of this type is returned as a trait impl by a method").unwrap();
440 writeln!(w, "pub(crate) extern \"C\" fn {}_clone_void(this_ptr: *const c_void) -> *mut c_void {{", struct_name).unwrap();
441 writeln!(w, "\tBox::into_raw(Box::new(unsafe {{ (*(this_ptr as *mut native{})).clone() }})) as *mut c_void", struct_name).unwrap();
442 writeln!(w, "}}").unwrap();
443 writeln!(w, "#[no_mangle]").unwrap();
444 writeln!(w, "pub extern \"C\" fn {}_clone(orig: &{}) -> {} {{", struct_name, struct_name, struct_name).unwrap();
445 writeln!(w, "\t{} {{ inner: Box::into_raw(Box::new(unsafe {{ &*orig.inner }}.clone())), is_owned: true }}", struct_name).unwrap();
446 writeln!(w, "}}").unwrap();
458 write_cpp_wrapper(cpp_headers, &format!("{}", ident), true);
461 /// Writes out all the relevant mappings for a Rust struct, deferring to writeln_opaque to generate
462 /// the struct itself, and then writing getters and setters for public, understood-type fields and
463 /// a constructor if every field is public.
464 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) {
465 let struct_name = &format!("{}", s.ident);
466 let export = export_status(&s.attrs);
468 ExportStatus::Export => {},
469 ExportStatus::TestOnly => return,
470 ExportStatus::NoExport => {
471 types.struct_ignored(&s.ident);
476 writeln_opaque(w, &s.ident, struct_name, &s.generics, &s.attrs, types, extra_headers, cpp_headers);
478 eprintln!("exporting fields for {}", struct_name);
479 if let syn::Fields::Named(fields) = &s.fields {
480 let mut gen_types = GenericTypes::new();
481 assert!(gen_types.learn_generics(&s.generics, types));
483 let mut all_fields_settable = true;
484 for field in fields.named.iter() {
485 if let syn::Visibility::Public(_) = field.vis {
486 let export = export_status(&field.attrs);
488 ExportStatus::Export => {},
489 ExportStatus::NoExport|ExportStatus::TestOnly => {
490 all_fields_settable = false;
495 if let Some(ident) = &field.ident {
496 let ref_type = syn::Type::Reference(syn::TypeReference {
497 and_token: syn::Token!(&)(Span::call_site()), lifetime: None, mutability: None,
498 elem: Box::new(field.ty.clone()) });
499 if types.understood_c_type(&ref_type, Some(&gen_types)) {
500 writeln_docs(w, &field.attrs, "");
501 write!(w, "#[no_mangle]\npub extern \"C\" fn {}_get_{}(this_ptr: &{}) -> ", struct_name, ident, struct_name).unwrap();
502 types.write_c_type(w, &ref_type, Some(&gen_types), true);
503 write!(w, " {{\n\tlet mut inner_val = &mut unsafe {{ &mut *this_ptr.inner }}.{};\n\t", ident).unwrap();
504 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);
505 if local_var { write!(w, "\n\t").unwrap(); }
506 types.write_to_c_conversion_inline_prefix(w, &ref_type, Some(&gen_types), true);
508 write!(w, "inner_val").unwrap();
510 write!(w, "(*inner_val)").unwrap();
512 types.write_to_c_conversion_inline_suffix(w, &ref_type, Some(&gen_types), true);
513 writeln!(w, "\n}}").unwrap();
516 if types.understood_c_type(&field.ty, Some(&gen_types)) {
517 writeln_docs(w, &field.attrs, "");
518 write!(w, "#[no_mangle]\npub extern \"C\" fn {}_set_{}(this_ptr: &mut {}, mut val: ", struct_name, ident, struct_name).unwrap();
519 types.write_c_type(w, &field.ty, Some(&gen_types), false);
520 write!(w, ") {{\n\t").unwrap();
521 let local_var = types.write_from_c_conversion_new_var(w, &syn::Ident::new("val", Span::call_site()), &field.ty, Some(&gen_types));
522 if local_var { write!(w, "\n\t").unwrap(); }
523 write!(w, "unsafe {{ &mut *this_ptr.inner }}.{} = ", ident).unwrap();
524 types.write_from_c_conversion_prefix(w, &field.ty, Some(&gen_types));
525 write!(w, "val").unwrap();
526 types.write_from_c_conversion_suffix(w, &field.ty, Some(&gen_types));
527 writeln!(w, ";\n}}").unwrap();
528 } else { all_fields_settable = false; }
529 } else { all_fields_settable = false; }
530 } else { all_fields_settable = false; }
533 if all_fields_settable {
534 // Build a constructor!
535 write!(w, "#[must_use]\n#[no_mangle]\npub extern \"C\" fn {}_new(", struct_name).unwrap();
536 for (idx, field) in fields.named.iter().enumerate() {
537 if idx != 0 { write!(w, ", ").unwrap(); }
538 write!(w, "mut {}_arg: ", field.ident.as_ref().unwrap()).unwrap();
539 types.write_c_type(w, &field.ty, Some(&gen_types), false);
541 write!(w, ") -> {} {{\n\t", struct_name).unwrap();
542 for field in fields.named.iter() {
543 let field_name = format!("{}_arg", field.ident.as_ref().unwrap());
544 if types.write_from_c_conversion_new_var(w, &syn::Ident::new(&field_name, Span::call_site()), &field.ty, Some(&gen_types)) {
545 write!(w, "\n\t").unwrap();
548 writeln!(w, "{} {{ inner: Box::into_raw(Box::new(native{} {{", struct_name, s.ident).unwrap();
549 for field in fields.named.iter() {
550 write!(w, "\t\t{}: ", field.ident.as_ref().unwrap()).unwrap();
551 types.write_from_c_conversion_prefix(w, &field.ty, Some(&gen_types));
552 write!(w, "{}_arg", field.ident.as_ref().unwrap()).unwrap();
553 types.write_from_c_conversion_suffix(w, &field.ty, Some(&gen_types));
554 writeln!(w, ",").unwrap();
556 writeln!(w, "\t}})), is_owned: true }}\n}}").unwrap();
560 types.struct_imported(&s.ident, struct_name.clone());
563 /// Prints a relevant conversion for impl *
565 /// For simple impl Struct {}s, this just outputs the wrapper functions as Struct_fn_name() { .. }.
567 /// For impl Trait for Struct{}s, this non-exported generates wrapper functions as
568 /// Trait_Struct_fn_name and a Struct_as_Trait(&struct) -> Trait function which returns a populated
569 /// Trait struct containing a pointer to the passed struct's inner field and the wrapper functions.
571 /// A few non-crate Traits are hard-coded including Default.
572 fn writeln_impl<W: std::io::Write>(w: &mut W, i: &syn::ItemImpl, types: &mut TypeResolver) {
573 if let &syn::Type::Path(ref p) = &*i.self_ty {
574 if p.qself.is_some() { unimplemented!(); }
575 if let Some(ident) = single_ident_generic_path_to_ident(&p.path) {
576 if let Some(resolved_path) = types.maybe_resolve_non_ignored_ident(&ident) {
577 let mut gen_types = GenericTypes::new();
578 if !gen_types.learn_generics(&i.generics, types) {
579 eprintln!("Not implementing anything for impl {} due to not understood generics", ident);
583 if i.defaultness.is_some() || i.unsafety.is_some() { unimplemented!(); }
584 if let Some(trait_path) = i.trait_.as_ref() {
585 if trait_path.0.is_some() { unimplemented!(); }
586 if types.understood_c_path(&trait_path.1) {
587 let full_trait_path = types.resolve_path(&trait_path.1, None);
588 let trait_obj = *types.crate_types.traits.get(&full_trait_path).unwrap();
589 // We learn the associated types maping from the original trait object.
590 // That's great, except that they are unresolved idents, so if we learn
591 // mappings from a trai defined in a different file, we may mis-resolve or
592 // fail to resolve the mapped types.
593 gen_types.learn_associated_types(trait_obj, types);
594 let mut impl_associated_types = HashMap::new();
595 for item in i.items.iter() {
597 syn::ImplItem::Type(t) => {
598 if let syn::Type::Path(p) = &t.ty {
599 if let Some(id) = single_ident_generic_path_to_ident(&p.path) {
600 impl_associated_types.insert(&t.ident, id);
608 let export = export_status(&trait_obj.attrs);
610 ExportStatus::Export => {},
611 ExportStatus::NoExport|ExportStatus::TestOnly => return,
614 // For cases where we have a concrete native object which implements a
615 // trait and need to return the C-mapped version of the trait, provide a
616 // From<> implementation which does all the work to ensure free is handled
617 // properly. This way we can call this method from deep in the
618 // type-conversion logic without actually knowing the concrete native type.
619 writeln!(w, "impl From<native{}> for crate::{} {{", ident, full_trait_path).unwrap();
620 writeln!(w, "\tfn from(obj: native{}) -> Self {{", ident).unwrap();
621 writeln!(w, "\t\tlet mut rust_obj = {} {{ inner: Box::into_raw(Box::new(obj)), is_owned: true }};", ident).unwrap();
622 writeln!(w, "\t\tlet mut ret = {}_as_{}(&rust_obj);", ident, trait_obj.ident).unwrap();
623 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();
624 writeln!(w, "\t\trust_obj.inner = std::ptr::null_mut();").unwrap();
625 writeln!(w, "\t\tret.free = Some({}_free_void);", ident).unwrap();
626 writeln!(w, "\t\tret\n\t}}\n}}").unwrap();
628 write!(w, "#[no_mangle]\npub extern \"C\" fn {}_as_{}(this_arg: *const {}) -> crate::{} {{\n", ident, trait_obj.ident, ident, full_trait_path).unwrap();
629 writeln!(w, "\tcrate::{} {{", full_trait_path).unwrap();
630 writeln!(w, "\t\tthis_arg: unsafe {{ (*this_arg).inner as *mut c_void }},").unwrap();
631 writeln!(w, "\t\tfree: None,").unwrap();
633 macro_rules! write_meth {
634 ($m: expr, $trait: expr, $indent: expr) => {
635 let trait_method = $trait.items.iter().filter_map(|item| {
636 if let syn::TraitItem::Method(t_m) = item { Some(t_m) } else { None }
637 }).find(|trait_meth| trait_meth.sig.ident == $m.sig.ident).unwrap();
638 match export_status(&trait_method.attrs) {
639 ExportStatus::Export => {},
640 ExportStatus::NoExport => {
641 write!(w, "{}\t\t//XXX: Need to export {}\n", $indent, $m.sig.ident).unwrap();
644 ExportStatus::TestOnly => continue,
647 let mut printed = false;
648 if let syn::ReturnType::Type(_, rtype) = &$m.sig.output {
649 if let syn::Type::Reference(r) = &**rtype {
650 write!(w, "\n\t\t{}{}: ", $indent, $m.sig.ident).unwrap();
651 types.write_empty_rust_val(Some(&gen_types), w, &*r.elem);
652 writeln!(w, ",\n{}\t\tset_{}: Some({}_{}_set_{}),", $indent, $m.sig.ident, ident, trait_obj.ident, $m.sig.ident).unwrap();
657 write!(w, "{}\t\t{}: {}_{}_{},\n", $indent, $m.sig.ident, ident, trait_obj.ident, $m.sig.ident).unwrap();
661 for item in trait_obj.items.iter() {
663 syn::TraitItem::Method(m) => {
664 write_meth!(m, trait_obj, "");
669 walk_supertraits!(trait_obj, types, (
671 writeln!(w, "\t\tclone: Some({}_clone_void),", ident).unwrap();
674 if let Some(supertrait_obj) = types.crate_types.traits.get(s) {
675 writeln!(w, "\t\t{}: crate::{} {{", t, s).unwrap();
676 writeln!(w, "\t\t\tthis_arg: unsafe {{ (*this_arg).inner as *mut c_void }},").unwrap();
677 writeln!(w, "\t\t\tfree: None,").unwrap();
678 for item in supertrait_obj.items.iter() {
680 syn::TraitItem::Method(m) => {
681 write_meth!(m, supertrait_obj, "\t");
686 write!(w, "\t\t}},\n").unwrap();
690 write!(w, "\t}}\n}}\nuse {}::{} as {}TraitImport;\n", types.orig_crate, full_trait_path, trait_obj.ident).unwrap();
692 macro_rules! impl_meth {
693 ($m: expr, $trait: expr, $indent: expr) => {
694 let trait_method = $trait.items.iter().filter_map(|item| {
695 if let syn::TraitItem::Method(t_m) = item { Some(t_m) } else { None }
696 }).find(|trait_meth| trait_meth.sig.ident == $m.sig.ident).unwrap();
697 match export_status(&trait_method.attrs) {
698 ExportStatus::Export => {},
699 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
702 if let syn::ReturnType::Type(_, _) = &$m.sig.output {
703 writeln!(w, "#[must_use]").unwrap();
705 write!(w, "extern \"C\" fn {}_{}_{}(", ident, trait_obj.ident, $m.sig.ident).unwrap();
706 gen_types.push_ctx();
707 assert!(gen_types.learn_generics(&$m.sig.generics, types));
708 write_method_params(w, &$m.sig, "c_void", types, Some(&gen_types), true, true);
709 write!(w, " {{\n\t").unwrap();
710 write_method_var_decl_body(w, &$m.sig, "", types, Some(&gen_types), false);
711 let mut takes_self = false;
712 for inp in $m.sig.inputs.iter() {
713 if let syn::FnArg::Receiver(_) = inp {
718 write!(w, "unsafe {{ &mut *(this_arg as *mut native{}) }}.{}(", ident, $m.sig.ident).unwrap();
720 write!(w, "{}::{}::{}(", types.orig_crate, resolved_path, $m.sig.ident).unwrap();
723 let mut real_type = "".to_string();
724 match &$m.sig.output {
725 syn::ReturnType::Type(_, rtype) => {
726 if let Some(mut remaining_path) = first_seg_self(&*rtype) {
727 if let Some(associated_seg) = get_single_remaining_path_seg(&mut remaining_path) {
728 real_type = format!("{}", impl_associated_types.get(associated_seg).unwrap());
734 write_method_call_params(w, &$m.sig, "", types, Some(&gen_types), &real_type, false);
736 write!(w, "\n}}\n").unwrap();
737 if let syn::ReturnType::Type(_, rtype) = &$m.sig.output {
738 if let syn::Type::Reference(r) = &**rtype {
739 assert_eq!($m.sig.inputs.len(), 1); // Must only take self
740 writeln!(w, "extern \"C\" fn {}_{}_set_{}(trait_self_arg: &{}) {{", ident, trait_obj.ident, $m.sig.ident, trait_obj.ident).unwrap();
741 writeln!(w, "\t// This is a bit race-y in the general case, but for our specific use-cases today, we're safe").unwrap();
742 writeln!(w, "\t// Specifically, we must ensure that the first time we're called it can never be in parallel").unwrap();
743 write!(w, "\tif ").unwrap();
744 types.write_empty_rust_val_check(Some(&gen_types), w, &*r.elem, &format!("trait_self_arg.{}", $m.sig.ident));
745 writeln!(w, " {{").unwrap();
746 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();
747 writeln!(w, "\t}}").unwrap();
748 writeln!(w, "}}").unwrap();
754 for item in i.items.iter() {
756 syn::ImplItem::Method(m) => {
757 impl_meth!(m, trait_obj, "");
759 syn::ImplItem::Type(_) => {},
760 _ => unimplemented!(),
763 walk_supertraits!(trait_obj, types, (
765 if let Some(supertrait_obj) = types.crate_types.traits.get(s).cloned() {
766 writeln!(w, "use {}::{} as native{}Trait;", types.orig_crate, s, t).unwrap();
767 for item in supertrait_obj.items.iter() {
769 syn::TraitItem::Method(m) => {
770 impl_meth!(m, supertrait_obj, "\t");
778 write!(w, "\n").unwrap();
779 } else if let Some(trait_ident) = trait_path.1.get_ident() {
780 //XXX: implement for other things like ToString
781 match &format!("{}", trait_ident) as &str {
784 write!(w, "#[must_use]\n#[no_mangle]\npub extern \"C\" fn {}_default() -> {} {{\n", ident, ident).unwrap();
785 write!(w, "\t{} {{ inner: Box::into_raw(Box::new(Default::default())), is_owned: true }}\n", ident).unwrap();
786 write!(w, "}}\n").unwrap();
789 // If we have no generics, try a manual implementation:
790 _ if p.path.get_ident().is_some() => maybe_convert_trait_impl(w, &trait_path.1, &ident, types),
793 } else if p.path.get_ident().is_some() {
794 // If we have no generics, try a manual implementation:
795 maybe_convert_trait_impl(w, &trait_path.1, &ident, types);
798 let declared_type = (*types.get_declared_type(&ident).unwrap()).clone();
799 for item in i.items.iter() {
801 syn::ImplItem::Method(m) => {
802 if let syn::Visibility::Public(_) = m.vis {
803 match export_status(&m.attrs) {
804 ExportStatus::Export => {},
805 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
807 if m.defaultness.is_some() { unimplemented!(); }
808 writeln_docs(w, &m.attrs, "");
809 if let syn::ReturnType::Type(_, _) = &m.sig.output {
810 writeln!(w, "#[must_use]").unwrap();
812 write!(w, "#[no_mangle]\npub extern \"C\" fn {}_{}(", ident, m.sig.ident).unwrap();
813 let ret_type = match &declared_type {
814 DeclType::MirroredEnum => format!("{}", ident),
815 DeclType::StructImported => format!("{}", ident),
816 _ => unimplemented!(),
818 gen_types.push_ctx();
819 assert!(gen_types.learn_generics(&m.sig.generics, types));
820 write_method_params(w, &m.sig, &ret_type, types, Some(&gen_types), false, true);
821 write!(w, " {{\n\t").unwrap();
822 write_method_var_decl_body(w, &m.sig, "", types, Some(&gen_types), false);
823 let mut takes_self = false;
824 let mut takes_mut_self = false;
825 for inp in m.sig.inputs.iter() {
826 if let syn::FnArg::Receiver(r) = inp {
828 if r.mutability.is_some() { takes_mut_self = true; }
832 write!(w, "unsafe {{ &mut (*(this_arg.inner as *mut native{})) }}.{}(", ident, m.sig.ident).unwrap();
833 } else if takes_self {
834 write!(w, "unsafe {{ &*this_arg.inner }}.{}(", m.sig.ident).unwrap();
836 write!(w, "{}::{}::{}(", types.orig_crate, resolved_path, m.sig.ident).unwrap();
838 write_method_call_params(w, &m.sig, "", types, Some(&gen_types), &ret_type, false);
840 writeln!(w, "\n}}\n").unwrap();
848 eprintln!("Not implementing anything for {} due to no-resolve (probably the type isn't pub or its marked not exported)", ident);
854 /// Returns true if the enum will be mapped as an opaue (ie struct with a pointer to the underlying
855 /// type), otherwise it is mapped into a transparent, C-compatible version of itself.
856 fn is_enum_opaque(e: &syn::ItemEnum) -> bool {
857 for var in e.variants.iter() {
858 if let syn::Fields::Unit = var.fields {
859 } else if let syn::Fields::Named(fields) = &var.fields {
860 for field in fields.named.iter() {
861 match export_status(&field.attrs) {
862 ExportStatus::Export|ExportStatus::TestOnly => {},
863 ExportStatus::NoExport => return true,
873 /// Print a mapping of an enum. If all of the enum's fields are C-mapped in some form (or the enum
874 /// is unitary), we generate an equivalent enum with all types replaced with their C mapped
875 /// versions followed by conversion functions which map between the Rust version and the C mapped
877 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) {
878 match export_status(&e.attrs) {
879 ExportStatus::Export => {},
880 ExportStatus::NoExport|ExportStatus::TestOnly => return,
883 if is_enum_opaque(e) {
884 eprintln!("Skipping enum {} as it contains non-unit fields", e.ident);
885 writeln_opaque(w, &e.ident, &format!("{}", e.ident), &e.generics, &e.attrs, types, extra_headers, cpp_headers);
886 types.enum_ignored(&e.ident);
889 writeln_docs(w, &e.attrs, "");
891 if e.generics.lt_token.is_some() {
894 types.mirrored_enum_declared(&e.ident);
896 let mut needs_free = false;
898 writeln!(w, "#[must_use]\n#[derive(Clone)]\n#[repr(C)]\npub enum {} {{", e.ident).unwrap();
899 for var in e.variants.iter() {
900 assert_eq!(export_status(&var.attrs), ExportStatus::Export); // We can't partially-export a mirrored enum
901 writeln_docs(w, &var.attrs, "\t");
902 write!(w, "\t{}", var.ident).unwrap();
903 if let syn::Fields::Named(fields) = &var.fields {
905 writeln!(w, " {{").unwrap();
906 for field in fields.named.iter() {
907 if export_status(&field.attrs) == ExportStatus::TestOnly { continue; }
908 write!(w, "\t\t{}: ", field.ident.as_ref().unwrap()).unwrap();
909 types.write_c_type(w, &field.ty, None, false);
910 writeln!(w, ",").unwrap();
912 write!(w, "\t}}").unwrap();
914 if var.discriminant.is_some() { unimplemented!(); }
915 writeln!(w, ",").unwrap();
917 writeln!(w, "}}\nuse {}::{}::{} as native{};\nimpl {} {{", types.orig_crate, types.module_path, e.ident, e.ident, e.ident).unwrap();
919 macro_rules! write_conv {
920 ($fn_sig: expr, $to_c: expr, $ref: expr) => {
921 writeln!(w, "\t#[allow(unused)]\n\tpub(crate) fn {} {{\n\t\tmatch {} {{", $fn_sig, if $to_c { "native" } else { "self" }).unwrap();
922 for var in e.variants.iter() {
923 write!(w, "\t\t\t{}{}::{} ", if $to_c { "native" } else { "" }, e.ident, var.ident).unwrap();
924 if let syn::Fields::Named(fields) = &var.fields {
925 write!(w, "{{").unwrap();
926 for field in fields.named.iter() {
927 if export_status(&field.attrs) == ExportStatus::TestOnly { continue; }
928 write!(w, "{}{}, ", if $ref { "ref " } else { "mut " }, field.ident.as_ref().unwrap()).unwrap();
930 write!(w, "}} ").unwrap();
932 write!(w, "=>").unwrap();
933 if let syn::Fields::Named(fields) = &var.fields {
934 write!(w, " {{\n\t\t\t\t").unwrap();
935 for field in fields.named.iter() {
936 if export_status(&field.attrs) == ExportStatus::TestOnly { continue; }
937 let mut sink = ::std::io::sink();
938 let mut out: &mut dyn std::io::Write = if $ref { &mut sink } else { w };
939 let new_var = if $to_c {
940 types.write_to_c_conversion_new_var(&mut out, field.ident.as_ref().unwrap(), &field.ty, None, false)
942 types.write_from_c_conversion_new_var(&mut out, field.ident.as_ref().unwrap(), &field.ty, None)
946 write!(w, "let mut {}_nonref = (*{}).clone();\n\t\t\t\t", field.ident.as_ref().unwrap(), field.ident.as_ref().unwrap()).unwrap();
948 let nonref_ident = syn::Ident::new(&format!("{}_nonref", field.ident.as_ref().unwrap()), Span::call_site());
950 types.write_to_c_conversion_new_var(w, &nonref_ident, &field.ty, None, false);
952 types.write_from_c_conversion_new_var(w, &nonref_ident, &field.ty, None);
954 write!(w, "\n\t\t\t\t").unwrap();
957 write!(w, "\n\t\t\t\t").unwrap();
961 } else { write!(w, " ").unwrap(); }
962 write!(w, "{}{}::{}", if $to_c { "" } else { "native" }, e.ident, var.ident).unwrap();
963 if let syn::Fields::Named(fields) = &var.fields {
964 write!(w, " {{").unwrap();
965 for field in fields.named.iter() {
966 if export_status(&field.attrs) == ExportStatus::TestOnly { continue; }
967 write!(w, "\n\t\t\t\t\t{}: ", field.ident.as_ref().unwrap()).unwrap();
969 types.write_to_c_conversion_inline_prefix(w, &field.ty, None, false);
971 types.write_from_c_conversion_prefix(w, &field.ty, None);
974 field.ident.as_ref().unwrap(),
975 if $ref { "_nonref" } else { "" }).unwrap();
977 types.write_to_c_conversion_inline_suffix(w, &field.ty, None, false);
979 types.write_from_c_conversion_suffix(w, &field.ty, None);
981 write!(w, ",").unwrap();
983 writeln!(w, "\n\t\t\t\t}}").unwrap();
984 write!(w, "\t\t\t}}").unwrap();
986 writeln!(w, ",").unwrap();
988 writeln!(w, "\t\t}}\n\t}}").unwrap();
992 write_conv!(format!("to_native(&self) -> native{}", e.ident), false, true);
993 write_conv!(format!("into_native(self) -> native{}", e.ident), false, false);
994 write_conv!(format!("from_native(native: &native{}) -> Self", e.ident), true, true);
995 write_conv!(format!("native_into(native: native{}) -> Self", e.ident), true, false);
996 writeln!(w, "}}").unwrap();
999 writeln!(w, "#[no_mangle]\npub extern \"C\" fn {}_free(this_ptr: {}) {{ }}", e.ident, e.ident).unwrap();
1001 writeln!(w, "#[no_mangle]").unwrap();
1002 writeln!(w, "pub extern \"C\" fn {}_clone(orig: &{}) -> {} {{", e.ident, e.ident, e.ident).unwrap();
1003 writeln!(w, "\torig.clone()").unwrap();
1004 writeln!(w, "}}").unwrap();
1005 write_cpp_wrapper(cpp_headers, &format!("{}", e.ident), needs_free);
1008 fn writeln_fn<'a, 'b, W: std::io::Write>(w: &mut W, f: &'a syn::ItemFn, types: &mut TypeResolver<'b, 'a>) {
1009 match export_status(&f.attrs) {
1010 ExportStatus::Export => {},
1011 ExportStatus::NoExport|ExportStatus::TestOnly => return,
1013 writeln_docs(w, &f.attrs, "");
1015 let mut gen_types = GenericTypes::new();
1016 if !gen_types.learn_generics(&f.sig.generics, types) { return; }
1018 write!(w, "#[no_mangle]\npub extern \"C\" fn {}(", f.sig.ident).unwrap();
1019 write_method_params(w, &f.sig, "", types, Some(&gen_types), false, true);
1020 write!(w, " {{\n\t").unwrap();
1021 write_method_var_decl_body(w, &f.sig, "", types, Some(&gen_types), false);
1022 write!(w, "{}::{}::{}(", types.orig_crate, types.module_path, f.sig.ident).unwrap();
1023 write_method_call_params(w, &f.sig, "", types, Some(&gen_types), "", false);
1024 writeln!(w, "\n}}\n").unwrap();
1027 // ********************************
1028 // *** File/Crate Walking Logic ***
1029 // ********************************
1031 /// Simple utility to walk the modules in a crate - iterating over the modules (with file paths) in
1033 struct FileIter<'a, I: Iterator<Item = &'a syn::Item>> {
1039 impl<'a, I: Iterator<Item = &'a syn::Item>> Iterator for FileIter<'a, I> {
1040 type Item = (String, String, &'a syn::ItemMod);
1041 fn next(&mut self) -> std::option::Option<<Self as std::iter::Iterator>::Item> {
1043 match self.item_iter.next() {
1044 Some(syn::Item::Mod(m)) => {
1045 if let syn::Visibility::Public(_) = m.vis {
1046 match export_status(&m.attrs) {
1047 ExportStatus::Export => {},
1048 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1051 let f_path = format!("{}/{}.rs", (self.path.as_ref() as &Path).parent().unwrap().display(), m.ident);
1052 let new_mod = if self.module.is_empty() { format!("{}", m.ident) } else { format!("{}::{}", self.module, m.ident) };
1053 if let Ok(_) = File::open(&format!("{}/{}", self.in_dir, f_path)) {
1054 return Some((f_path, new_mod, m));
1057 format!("{}/{}/mod.rs", (self.path.as_ref() as &Path).parent().unwrap().display(), m.ident),
1063 None => return None,
1068 fn file_iter<'a>(file: &'a syn::File, in_dir: &'a str, path: &'a str, module: &'a str) ->
1069 impl Iterator<Item = (String, String, &'a syn::ItemMod)> + 'a {
1070 FileIter { in_dir, path, module, item_iter: file.items.iter() }
1073 /// A struct containing the syn::File AST for each file in the crate.
1074 struct FullLibraryAST {
1075 files: HashMap<String, syn::File>,
1078 /// Do the Real Work of mapping an original file to C-callable wrappers. Creates a new file at
1079 /// `out_path` and fills it with wrapper structs/functions to allow calling the things in the AST
1080 /// at `module` from C.
1081 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) {
1082 let syntax = if let Some(ast) = libast.files.get(module) { ast } else { return };
1084 assert!(syntax.shebang.is_none()); // Not sure what this is, hope we dont have one
1086 let new_file_path = format!("{}/{}", out_dir, path);
1087 let _ = std::fs::create_dir((&new_file_path.as_ref() as &std::path::Path).parent().unwrap());
1088 let mut out = std::fs::OpenOptions::new().write(true).create(true).truncate(true)
1089 .open(new_file_path).expect("Unable to open new src file");
1091 assert_eq!(export_status(&syntax.attrs), ExportStatus::Export);
1092 writeln_docs(&mut out, &syntax.attrs, "");
1094 if path.ends_with("/lib.rs") {
1095 // Special-case the top-level lib.rs with various lint allows and a pointer to the c_types
1096 // and bitcoin hand-written modules.
1097 writeln!(out, "#![allow(unknown_lints)]").unwrap();
1098 writeln!(out, "#![allow(non_camel_case_types)]").unwrap();
1099 writeln!(out, "#![allow(non_snake_case)]").unwrap();
1100 writeln!(out, "#![allow(unused_imports)]").unwrap();
1101 writeln!(out, "#![allow(unused_variables)]").unwrap();
1102 writeln!(out, "#![allow(unused_mut)]").unwrap();
1103 writeln!(out, "#![allow(unused_parens)]").unwrap();
1104 writeln!(out, "#![allow(unused_unsafe)]").unwrap();
1105 writeln!(out, "#![allow(unused_braces)]").unwrap();
1106 writeln!(out, "mod c_types;").unwrap();
1107 writeln!(out, "mod bitcoin;").unwrap();
1109 writeln!(out, "\nuse std::ffi::c_void;\nuse bitcoin::hashes::Hash;\nuse crate::c_types::*;\n").unwrap();
1112 for (path, new_mod, m) in file_iter(&syntax, in_dir, path, &module) {
1113 writeln_docs(&mut out, &m.attrs, "");
1114 writeln!(out, "pub mod {};", m.ident).unwrap();
1115 convert_file(libast, crate_types, in_dir, out_dir, &path,
1116 orig_crate, &new_mod, header_file, cpp_header_file);
1119 eprintln!("Converting {} entries...", path);
1121 let mut type_resolver = TypeResolver::new(orig_crate, module, crate_types);
1123 for item in syntax.items.iter() {
1125 syn::Item::Use(u) => type_resolver.process_use(&mut out, &u),
1126 syn::Item::Static(_) => {},
1127 syn::Item::Enum(e) => {
1128 if let syn::Visibility::Public(_) = e.vis {
1129 writeln_enum(&mut out, &e, &mut type_resolver, header_file, cpp_header_file);
1132 syn::Item::Impl(i) => {
1133 writeln_impl(&mut out, &i, &mut type_resolver);
1135 syn::Item::Struct(s) => {
1136 if let syn::Visibility::Public(_) = s.vis {
1137 writeln_struct(&mut out, &s, &mut type_resolver, header_file, cpp_header_file);
1140 syn::Item::Trait(t) => {
1141 if let syn::Visibility::Public(_) = t.vis {
1142 writeln_trait(&mut out, &t, &mut type_resolver, header_file, cpp_header_file);
1145 syn::Item::Mod(_) => {}, // We don't have to do anything - the top loop handles these.
1146 syn::Item::Const(c) => {
1147 // Re-export any primitive-type constants.
1148 if let syn::Visibility::Public(_) = c.vis {
1149 if let syn::Type::Path(p) = &*c.ty {
1150 let resolved_path = type_resolver.resolve_path(&p.path, None);
1151 if type_resolver.is_primitive(&resolved_path) {
1152 writeln!(out, "\n#[no_mangle]").unwrap();
1153 writeln!(out, "pub static {}: {} = {}::{}::{};", c.ident, resolved_path, orig_crate, module, c.ident).unwrap();
1158 syn::Item::Type(t) => {
1159 if let syn::Visibility::Public(_) = t.vis {
1160 match export_status(&t.attrs) {
1161 ExportStatus::Export => {},
1162 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1165 let mut process_alias = true;
1166 for tok in t.generics.params.iter() {
1167 if let syn::GenericParam::Lifetime(_) = tok {}
1168 else { process_alias = false; }
1172 syn::Type::Path(_) =>
1173 writeln_opaque(&mut out, &t.ident, &format!("{}", t.ident), &t.generics, &t.attrs, &type_resolver, header_file, cpp_header_file),
1179 syn::Item::Fn(f) => {
1180 if let syn::Visibility::Public(_) = f.vis {
1181 writeln_fn(&mut out, &f, &mut type_resolver);
1184 syn::Item::Macro(m) => {
1185 if m.ident.is_none() { // If its not a macro definition
1186 convert_macro(&mut out, &m.mac.path, &m.mac.tokens, &type_resolver);
1189 syn::Item::Verbatim(_) => {},
1190 syn::Item::ExternCrate(_) => {},
1191 _ => unimplemented!(),
1195 out.flush().unwrap();
1198 /// Load the AST for each file in the crate, filling the FullLibraryAST object
1199 fn load_ast(in_dir: &str, path: &str, module: String, ast_storage: &mut FullLibraryAST) {
1200 eprintln!("Loading {}{}...", in_dir, path);
1202 let mut file = File::open(format!("{}/{}", in_dir, path)).expect("Unable to open file");
1203 let mut src = String::new();
1204 file.read_to_string(&mut src).expect("Unable to read file");
1205 let syntax = syn::parse_file(&src).expect("Unable to parse file");
1207 assert_eq!(export_status(&syntax.attrs), ExportStatus::Export);
1209 for (path, new_mod, _) in file_iter(&syntax, in_dir, path, &module) {
1210 load_ast(in_dir, &path, new_mod, ast_storage);
1212 ast_storage.files.insert(module, syntax);
1215 /// Insert ident -> absolute Path resolutions into imports from the given UseTree and path-prefix.
1216 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>) {
1218 syn::UseTree::Path(p) => {
1219 path.push(syn::PathSegment { ident: p.ident.clone(), arguments: syn::PathArguments::None });
1220 process_use_intern(&p.tree, path, imports);
1222 syn::UseTree::Name(n) => {
1223 path.push(syn::PathSegment { ident: n.ident.clone(), arguments: syn::PathArguments::None });
1224 imports.insert(&n.ident, syn::Path { leading_colon: Some(syn::Token![::](Span::call_site())), segments: path });
1226 syn::UseTree::Group(g) => {
1227 for i in g.items.iter() {
1228 process_use_intern(i, path.clone(), imports);
1235 /// Map all the Paths in a Type into absolute paths given a set of imports (generated via process_use_intern)
1236 fn resolve_imported_refs(imports: &HashMap<&syn::Ident, syn::Path>, mut ty: syn::Type) -> syn::Type {
1238 syn::Type::Path(p) => {
1239 if let Some(ident) = p.path.get_ident() {
1240 if let Some(newpath) = imports.get(ident) {
1241 p.path = newpath.clone();
1243 } else { unimplemented!(); }
1245 syn::Type::Reference(r) => {
1246 r.elem = Box::new(resolve_imported_refs(imports, (*r.elem).clone()));
1248 syn::Type::Slice(s) => {
1249 s.elem = Box::new(resolve_imported_refs(imports, (*s.elem).clone()));
1251 syn::Type::Tuple(t) => {
1252 for e in t.elems.iter_mut() {
1253 *e = resolve_imported_refs(imports, e.clone());
1256 _ => unimplemented!(),
1261 /// Walk the FullLibraryAST, deciding how things will be mapped and adding tracking to CrateTypes.
1262 fn walk_ast<'a>(in_dir: &str, path: &str, module: String, ast_storage: &'a FullLibraryAST, crate_types: &mut CrateTypes<'a>) {
1263 let syntax = if let Some(ast) = ast_storage.files.get(&module) { ast } else { return };
1264 assert_eq!(export_status(&syntax.attrs), ExportStatus::Export);
1266 for (path, new_mod, _) in file_iter(&syntax, in_dir, path, &module) {
1267 walk_ast(in_dir, &path, new_mod, ast_storage, crate_types);
1270 let mut import_maps = HashMap::new();
1272 for item in syntax.items.iter() {
1274 syn::Item::Use(u) => {
1275 process_use_intern(&u.tree, syn::punctuated::Punctuated::new(), &mut import_maps);
1277 syn::Item::Struct(s) => {
1278 if let syn::Visibility::Public(_) = s.vis {
1279 match export_status(&s.attrs) {
1280 ExportStatus::Export => {},
1281 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1283 let struct_path = format!("{}::{}", module, s.ident);
1284 crate_types.opaques.insert(struct_path, &s.ident);
1287 syn::Item::Trait(t) => {
1288 if let syn::Visibility::Public(_) = t.vis {
1289 match export_status(&t.attrs) {
1290 ExportStatus::Export => {},
1291 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1293 let trait_path = format!("{}::{}", module, t.ident);
1294 crate_types.traits.insert(trait_path, &t);
1297 syn::Item::Type(t) => {
1298 if let syn::Visibility::Public(_) = t.vis {
1299 match export_status(&t.attrs) {
1300 ExportStatus::Export => {},
1301 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1303 let type_path = format!("{}::{}", module, t.ident);
1304 let mut process_alias = true;
1305 for tok in t.generics.params.iter() {
1306 if let syn::GenericParam::Lifetime(_) = tok {}
1307 else { process_alias = false; }
1311 syn::Type::Path(_) => {
1312 // If its a path with no generics, assume we don't map the aliased type and map it opaque
1313 crate_types.opaques.insert(type_path, &t.ident);
1316 crate_types.type_aliases.insert(type_path, resolve_imported_refs(&import_maps, (*t.ty).clone()));
1322 syn::Item::Enum(e) if is_enum_opaque(e) => {
1323 if let syn::Visibility::Public(_) = e.vis {
1324 match export_status(&e.attrs) {
1325 ExportStatus::Export => {},
1326 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1328 let enum_path = format!("{}::{}", module, e.ident);
1329 crate_types.opaques.insert(enum_path, &e.ident);
1332 syn::Item::Enum(e) => {
1333 if let syn::Visibility::Public(_) = e.vis {
1334 match export_status(&e.attrs) {
1335 ExportStatus::Export => {},
1336 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1338 let enum_path = format!("{}::{}", module, e.ident);
1339 crate_types.mirrored_enums.insert(enum_path, &e);
1348 let args: Vec<String> = env::args().collect();
1349 if args.len() != 7 {
1350 eprintln!("Usage: source/dir target/dir source_crate_name derived_templates.rs extra/includes.h extra/cpp/includes.hpp");
1354 let mut derived_templates = std::fs::OpenOptions::new().write(true).create(true).truncate(true)
1355 .open(&args[4]).expect("Unable to open new header file");
1356 let mut header_file = std::fs::OpenOptions::new().write(true).create(true).truncate(true)
1357 .open(&args[5]).expect("Unable to open new header file");
1358 let mut cpp_header_file = std::fs::OpenOptions::new().write(true).create(true).truncate(true)
1359 .open(&args[6]).expect("Unable to open new header file");
1361 writeln!(header_file, "#if defined(__GNUC__)\n#define MUST_USE_STRUCT __attribute__((warn_unused))").unwrap();
1362 writeln!(header_file, "#else\n#define MUST_USE_STRUCT\n#endif").unwrap();
1363 writeln!(header_file, "#if defined(__GNUC__)\n#define MUST_USE_RES __attribute__((warn_unused_result))").unwrap();
1364 writeln!(header_file, "#else\n#define MUST_USE_RES\n#endif").unwrap();
1365 writeln!(cpp_header_file, "#include <string.h>\nnamespace LDK {{").unwrap();
1367 // First parse the full crate's ASTs, caching them so that we can hold references to the AST
1368 // objects in other datastructures:
1369 let mut libast = FullLibraryAST { files: HashMap::new() };
1370 load_ast(&args[1], "/lib.rs", "".to_string(), &mut libast);
1372 // ...then walk the ASTs tracking what types we will map, and how, so that we can resolve them
1373 // when parsing other file ASTs...
1374 let mut libtypes = CrateTypes { traits: HashMap::new(), opaques: HashMap::new(), mirrored_enums: HashMap::new(),
1375 type_aliases: HashMap::new(), templates_defined: HashMap::default(), template_file: &mut derived_templates };
1376 walk_ast(&args[1], "/lib.rs", "".to_string(), &libast, &mut libtypes);
1378 // ... finally, do the actual file conversion/mapping, writing out types as we go.
1379 convert_file(&libast, &mut libtypes, &args[1], &args[2], "/lib.rs", &args[3], "", &mut header_file, &mut cpp_header_file);
1381 // For container templates which we created while walking the crate, make sure we add C++
1382 // mapped types so that C++ users can utilize the auto-destructors available.
1383 for (ty, has_destructor) in libtypes.templates_defined.iter() {
1384 write_cpp_wrapper(&mut cpp_header_file, ty, *has_destructor);
1386 writeln!(cpp_header_file, "}}").unwrap();
1388 header_file.flush().unwrap();
1389 cpp_header_file.flush().unwrap();
1390 derived_templates.flush().unwrap();