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 // First try to resolve path to find in-crate traits, but if that doesn't work
96 // assume its a prelude trait (eg Clone, etc) and just use the single ident.
97 if let Some(path) = $types.maybe_resolve_path(&supertrait.path, None) {
98 match (&path as &str, &supertrait.path.segments.iter().last().unwrap().ident) {
101 } else if let Some(ident) = supertrait.path.get_ident() {
102 match (&format!("{}", ident) as &str, &ident) {
106 panic!("Supertrait unresolvable and not single-ident");
109 syn::TypeParamBound::Lifetime(_) => unimplemented!(),
115 /// Prints a C-mapped trait object containing a void pointer and a jump table for each function in
116 /// the original trait.
117 /// Implements the native Rust trait and relevant parent traits for the new C-mapped trait.
119 /// Finally, implements Deref<MappedTrait> for MappedTrait which allows its use in types which need
120 /// a concrete Deref to the Rust trait.
121 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) {
122 let trait_name = format!("{}", t.ident);
123 match export_status(&t.attrs) {
124 ExportStatus::Export => {},
125 ExportStatus::NoExport|ExportStatus::TestOnly => return,
127 writeln_docs(w, &t.attrs, "");
129 let mut gen_types = GenericTypes::new();
130 assert!(gen_types.learn_generics(&t.generics, types));
131 gen_types.learn_associated_types(&t, types);
133 writeln!(w, "#[repr(C)]\npub struct {} {{", trait_name).unwrap();
134 writeln!(w, "\tpub this_arg: *mut c_void,").unwrap();
135 let mut generated_fields = Vec::new(); // Every field's name except this_arg, used in Clone generation
136 for item in t.items.iter() {
138 &syn::TraitItem::Method(ref m) => {
139 match export_status(&m.attrs) {
140 ExportStatus::NoExport => {
141 // NoExport in this context means we'll hit an unimplemented!() at runtime,
145 ExportStatus::Export => {},
146 ExportStatus::TestOnly => continue,
148 if m.default.is_some() { unimplemented!(); }
150 gen_types.push_ctx();
151 assert!(gen_types.learn_generics(&m.sig.generics, types));
153 writeln_docs(w, &m.attrs, "\t");
155 if let syn::ReturnType::Type(_, rtype) = &m.sig.output {
156 if let syn::Type::Reference(r) = &**rtype {
157 // We have to do quite a dance for trait functions which return references
158 // - they ultimately require us to have a native Rust object stored inside
159 // our concrete trait to return a reference to. However, users may wish to
160 // update the value to be returned each time the function is called (or, to
161 // make C copies of Rust impls equivalent, we have to be able to).
163 // Thus, we store a copy of the C-mapped type (which is just a pointer to
164 // the Rust type and a flag to indicate whether deallocation needs to
165 // happen) as well as provide an Option<>al function pointer which is
166 // called when the trait method is called which allows updating on the fly.
167 write!(w, "\tpub {}: ", m.sig.ident).unwrap();
168 generated_fields.push(format!("{}", m.sig.ident));
169 types.write_c_type(w, &*r.elem, Some(&gen_types), false);
170 writeln!(w, ",").unwrap();
171 writeln!(w, "\t/// Fill in the {} field as a reference to it will be given to Rust after this returns", m.sig.ident).unwrap();
172 writeln!(w, "\t/// Note that this takes a pointer to this object, not the this_ptr like other methods do").unwrap();
173 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();
174 writeln!(w, "\tpub set_{}: Option<extern \"C\" fn(&{})>,", m.sig.ident, trait_name).unwrap();
175 generated_fields.push(format!("set_{}", m.sig.ident));
176 // Note that cbindgen will now generate
177 // typedef struct Thing {..., set_thing: (const Thing*), ...} Thing;
178 // which does not compile since Thing is not defined before it is used.
179 writeln!(extra_headers, "struct LDK{};", trait_name).unwrap();
180 writeln!(extra_headers, "typedef struct LDK{} LDK{};", trait_name, trait_name).unwrap();
184 // Sadly, this currently doesn't do what we want, but it should be easy to get
185 // cbindgen to support it. See https://github.com/eqrion/cbindgen/issues/531
186 writeln!(w, "\t#[must_use]").unwrap();
189 write!(w, "\tpub {}: extern \"C\" fn (", m.sig.ident).unwrap();
190 generated_fields.push(format!("{}", m.sig.ident));
191 write_method_params(w, &m.sig, "c_void", types, Some(&gen_types), true, false);
192 writeln!(w, ",").unwrap();
196 &syn::TraitItem::Type(_) => {},
197 _ => unimplemented!(),
200 // Add functions which may be required for supertrait implementations.
201 walk_supertraits!(t, types, (
203 writeln!(w, "\tpub clone: Option<extern \"C\" fn (this_arg: *const c_void) -> *mut c_void>,").unwrap();
204 generated_fields.push("clone".to_owned());
206 ("std::cmp::Eq", _) => {
207 writeln!(w, "\tpub eq: extern \"C\" fn (this_arg: *const c_void, other_arg: &{}) -> bool,", trait_name).unwrap();
208 writeln!(extra_headers, "typedef struct LDK{} LDK{};", trait_name, trait_name).unwrap();
209 generated_fields.push("eq".to_owned());
211 ("std::hash::Hash", _) => {
212 writeln!(w, "\tpub hash: extern \"C\" fn (this_arg: *const c_void) -> u64,").unwrap();
213 generated_fields.push("hash".to_owned());
215 ("Send", _) => {}, ("Sync", _) => {},
217 // For in-crate supertraits, just store a C-mapped copy of the supertrait as a member.
218 if types.crate_types.traits.get(s).is_none() { unimplemented!(); }
219 writeln!(w, "\tpub {}: crate::{},", i, s).unwrap();
220 generated_fields.push(format!("{}", i));
223 writeln!(w, "\tpub free: Option<extern \"C\" fn(this_arg: *mut c_void)>,").unwrap();
224 generated_fields.push("free".to_owned());
225 writeln!(w, "}}").unwrap();
226 // Implement supertraits for the C-mapped struct.
227 walk_supertraits!(t, types, (
228 ("Send", _) => writeln!(w, "unsafe impl Send for {} {{}}", trait_name).unwrap(),
229 ("Sync", _) => writeln!(w, "unsafe impl Sync for {} {{}}", trait_name).unwrap(),
230 ("std::cmp::Eq", _) => {
231 writeln!(w, "impl std::cmp::Eq for {} {{}}", trait_name).unwrap();
232 writeln!(w, "impl std::cmp::PartialEq for {} {{", trait_name).unwrap();
233 writeln!(w, "\tfn eq(&self, o: &Self) -> bool {{ (self.eq)(self.this_arg, o) }}\n}}").unwrap();
235 ("std::hash::Hash", _) => {
236 writeln!(w, "impl std::hash::Hash for {} {{", trait_name).unwrap();
237 writeln!(w, "\tfn hash<H: std::hash::Hasher>(&self, hasher: &mut H) {{ hasher.write_u64((self.hash)(self.this_arg)) }}\n}}").unwrap();
240 writeln!(w, "#[no_mangle]").unwrap();
241 writeln!(w, "pub extern \"C\" fn {}_clone(orig: &{}) -> {} {{", trait_name, trait_name, trait_name).unwrap();
242 writeln!(w, "\t{} {{", trait_name).unwrap();
243 writeln!(w, "\t\tthis_arg: if let Some(f) = orig.clone {{ (f)(orig.this_arg) }} else {{ orig.this_arg }},").unwrap();
244 for field in generated_fields.iter() {
245 writeln!(w, "\t\t{}: orig.{}.clone(),", field, field).unwrap();
247 writeln!(w, "\t}}\n}}").unwrap();
248 writeln!(w, "impl Clone for {} {{", trait_name).unwrap();
249 writeln!(w, "\tfn clone(&self) -> Self {{").unwrap();
250 writeln!(w, "\t\t{}_clone(self)", trait_name).unwrap();
251 writeln!(w, "\t}}\n}}").unwrap();
254 if s != "util::events::MessageSendEventsProvider" { unimplemented!(); }
255 // XXX: We straight-up cheat here - instead of bothering to get the trait object we
256 // just print what we need since this is only used in one place.
257 writeln!(w, "impl lightning::{} for {} {{", s, trait_name).unwrap();
258 writeln!(w, "\tfn get_and_clear_pending_msg_events(&self) -> Vec<lightning::util::events::MessageSendEvent> {{").unwrap();
259 writeln!(w, "\t\t<crate::{} as lightning::{}>::get_and_clear_pending_msg_events(&self.{})", s, s, i).unwrap();
260 writeln!(w, "\t}}\n}}").unwrap();
264 // Finally, implement the original Rust trait for the newly created mapped trait.
265 writeln!(w, "\nuse {}::{}::{} as rust{};", types.orig_crate, types.module_path, t.ident, trait_name).unwrap();
266 write!(w, "impl rust{}", t.ident).unwrap();
267 maybe_write_generics(w, &t.generics, types, false);
268 writeln!(w, " for {} {{", trait_name).unwrap();
269 for item in t.items.iter() {
271 syn::TraitItem::Method(m) => {
272 if let ExportStatus::TestOnly = export_status(&m.attrs) { continue; }
273 if m.default.is_some() { unimplemented!(); }
274 if m.sig.constness.is_some() || m.sig.asyncness.is_some() || m.sig.unsafety.is_some() ||
275 m.sig.abi.is_some() || m.sig.variadic.is_some() {
278 gen_types.push_ctx();
279 assert!(gen_types.learn_generics(&m.sig.generics, types));
280 write!(w, "\tfn {}", m.sig.ident).unwrap();
281 types.write_rust_generic_param(w, Some(&gen_types), m.sig.generics.params.iter());
282 write!(w, "(").unwrap();
283 for inp in m.sig.inputs.iter() {
285 syn::FnArg::Receiver(recv) => {
286 if !recv.attrs.is_empty() || recv.reference.is_none() { unimplemented!(); }
287 write!(w, "&").unwrap();
288 if let Some(lft) = &recv.reference.as_ref().unwrap().1 {
289 write!(w, "'{} ", lft.ident).unwrap();
291 if recv.mutability.is_some() {
292 write!(w, "mut self").unwrap();
294 write!(w, "self").unwrap();
297 syn::FnArg::Typed(arg) => {
298 if !arg.attrs.is_empty() { unimplemented!(); }
300 syn::Pat::Ident(ident) => {
301 if !ident.attrs.is_empty() || ident.by_ref.is_some() ||
302 ident.mutability.is_some() || ident.subpat.is_some() {
305 write!(w, ", {}{}: ", if types.skip_arg(&*arg.ty, Some(&gen_types)) { "_" } else { "" }, ident.ident).unwrap();
307 _ => unimplemented!(),
309 types.write_rust_type(w, Some(&gen_types), &*arg.ty);
313 write!(w, ")").unwrap();
314 match &m.sig.output {
315 syn::ReturnType::Type(_, rtype) => {
316 write!(w, " -> ").unwrap();
317 types.write_rust_type(w, Some(&gen_types), &*rtype)
321 write!(w, " {{\n\t\t").unwrap();
322 match export_status(&m.attrs) {
323 ExportStatus::NoExport => {
328 if let syn::ReturnType::Type(_, rtype) = &m.sig.output {
329 if let syn::Type::Reference(r) = &**rtype {
330 assert_eq!(m.sig.inputs.len(), 1); // Must only take self!
331 writeln!(w, "if let Some(f) = self.set_{} {{", m.sig.ident).unwrap();
332 writeln!(w, "\t\t\t(f)(self);").unwrap();
333 write!(w, "\t\t}}\n\t\t").unwrap();
334 types.write_from_c_conversion_to_ref_prefix(w, &*r.elem, Some(&gen_types));
335 write!(w, "self.{}", m.sig.ident).unwrap();
336 types.write_from_c_conversion_to_ref_suffix(w, &*r.elem, Some(&gen_types));
337 writeln!(w, "\n\t}}").unwrap();
342 write_method_var_decl_body(w, &m.sig, "\t", types, Some(&gen_types), true);
343 write!(w, "(self.{})(", m.sig.ident).unwrap();
344 write_method_call_params(w, &m.sig, "\t", types, Some(&gen_types), "", true);
346 writeln!(w, "\n\t}}").unwrap();
349 &syn::TraitItem::Type(ref t) => {
350 if t.default.is_some() || t.generics.lt_token.is_some() { unimplemented!(); }
351 let mut bounds_iter = t.bounds.iter();
352 match bounds_iter.next().unwrap() {
353 syn::TypeParamBound::Trait(tr) => {
354 writeln!(w, "\ttype {} = crate::{};", t.ident, types.resolve_path(&tr.path, Some(&gen_types))).unwrap();
356 _ => unimplemented!(),
358 if bounds_iter.next().is_some() { unimplemented!(); }
360 _ => unimplemented!(),
363 writeln!(w, "}}\n").unwrap();
364 writeln!(w, "// We're essentially a pointer already, or at least a set of pointers, so allow us to be used").unwrap();
365 writeln!(w, "// directly as a Deref trait in higher-level structs:").unwrap();
366 writeln!(w, "impl std::ops::Deref for {} {{\n\ttype Target = Self;", trait_name).unwrap();
367 writeln!(w, "\tfn deref(&self) -> &Self {{\n\t\tself\n\t}}\n}}").unwrap();
369 writeln!(w, "/// Calls the free function if one is set").unwrap();
370 writeln!(w, "#[no_mangle]\npub extern \"C\" fn {}_free(this_ptr: {}) {{ }}", trait_name, trait_name).unwrap();
371 writeln!(w, "impl Drop for {} {{", trait_name).unwrap();
372 writeln!(w, "\tfn drop(&mut self) {{").unwrap();
373 writeln!(w, "\t\tif let Some(f) = self.free {{").unwrap();
374 writeln!(w, "\t\t\tf(self.this_arg);").unwrap();
375 writeln!(w, "\t\t}}\n\t}}\n}}").unwrap();
377 write_cpp_wrapper(cpp_headers, &trait_name, true);
378 types.trait_declared(&t.ident, t);
381 /// Write out a simple "opaque" type (eg structs) which contain a pointer to the native Rust type
382 /// and a flag to indicate whether Drop'ing the mapped struct drops the underlying Rust type.
384 /// Also writes out a _free function and a C++ wrapper which handles calling _free.
385 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) {
386 // If we directly read the original type by its original name, cbindgen hits
387 // https://github.com/eqrion/cbindgen/issues/286 Thus, instead, we import it as a temporary
388 // name and then reference it by that name, which works around the issue.
389 write!(w, "\nuse {}::{}::{} as native{}Import;\ntype native{} = native{}Import", types.orig_crate, types.module_path, ident, ident, ident, ident).unwrap();
390 maybe_write_generics(w, &generics, &types, true);
391 writeln!(w, ";\n").unwrap();
392 writeln!(extra_headers, "struct native{}Opaque;\ntypedef struct native{}Opaque LDKnative{};", ident, ident, ident).unwrap();
393 writeln_docs(w, &attrs, "");
394 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();
395 writeln!(w, "\t/// the Rust equivalent takes an Option, it may be set to null to indicate None.").unwrap();
396 writeln!(w, "\tpub inner: *mut native{},\n\tpub is_owned: bool,\n}}\n", ident).unwrap();
397 writeln!(w, "impl Drop for {} {{\n\tfn drop(&mut self) {{", struct_name).unwrap();
398 writeln!(w, "\t\tif self.is_owned && !self.inner.is_null() {{").unwrap();
399 writeln!(w, "\t\t\tlet _ = unsafe {{ Box::from_raw(self.inner) }};\n\t\t}}\n\t}}\n}}").unwrap();
400 writeln!(w, "#[no_mangle]\npub extern \"C\" fn {}_free(this_ptr: {}) {{ }}", struct_name, struct_name).unwrap();
401 writeln!(w, "#[allow(unused)]").unwrap();
402 writeln!(w, "/// Used only if an object of this type is returned as a trait impl by a method").unwrap();
403 writeln!(w, "extern \"C\" fn {}_free_void(this_ptr: *mut c_void) {{", struct_name).unwrap();
404 writeln!(w, "\tunsafe {{ let _ = Box::from_raw(this_ptr as *mut native{}); }}\n}}", struct_name).unwrap();
405 writeln!(w, "#[allow(unused)]").unwrap();
406 writeln!(w, "/// When moving out of the pointer, we have to ensure we aren't a reference, this makes that easy").unwrap();
407 writeln!(w, "impl {} {{", struct_name).unwrap();
408 writeln!(w, "\tpub(crate) fn take_ptr(mut self) -> *mut native{} {{", struct_name).unwrap();
409 writeln!(w, "\t\tassert!(self.is_owned);").unwrap();
410 writeln!(w, "\t\tlet ret = self.inner;").unwrap();
411 writeln!(w, "\t\tself.inner = std::ptr::null_mut();").unwrap();
412 writeln!(w, "\t\tret").unwrap();
413 writeln!(w, "\t}}\n}}").unwrap();
415 'attr_loop: for attr in attrs.iter() {
416 let tokens_clone = attr.tokens.clone();
417 let mut token_iter = tokens_clone.into_iter();
418 if let Some(token) = token_iter.next() {
420 TokenTree::Group(g) => {
421 if format!("{}", single_ident_generic_path_to_ident(&attr.path).unwrap()) == "derive" {
422 for id in g.stream().into_iter() {
423 if let TokenTree::Ident(i) = id {
425 writeln!(w, "impl Clone for {} {{", struct_name).unwrap();
426 writeln!(w, "\tfn clone(&self) -> Self {{").unwrap();
427 writeln!(w, "\t\tSelf {{").unwrap();
428 writeln!(w, "\t\t\tinner: Box::into_raw(Box::new(unsafe {{ &*self.inner }}.clone())),").unwrap();
429 writeln!(w, "\t\t\tis_owned: true,").unwrap();
430 writeln!(w, "\t\t}}\n\t}}\n}}").unwrap();
431 writeln!(w, "#[allow(unused)]").unwrap();
432 writeln!(w, "/// Used only if an object of this type is returned as a trait impl by a method").unwrap();
433 writeln!(w, "pub(crate) extern \"C\" fn {}_clone_void(this_ptr: *const c_void) -> *mut c_void {{", struct_name).unwrap();
434 writeln!(w, "\tBox::into_raw(Box::new(unsafe {{ (*(this_ptr as *mut native{})).clone() }})) as *mut c_void", struct_name).unwrap();
435 writeln!(w, "}}").unwrap();
436 writeln!(w, "#[no_mangle]").unwrap();
437 writeln!(w, "pub extern \"C\" fn {}_clone(orig: &{}) -> {} {{", struct_name, struct_name, struct_name).unwrap();
438 writeln!(w, "\t{} {{ inner: Box::into_raw(Box::new(unsafe {{ &*orig.inner }}.clone())), is_owned: true }}", struct_name).unwrap();
439 writeln!(w, "}}").unwrap();
451 write_cpp_wrapper(cpp_headers, &format!("{}", ident), true);
454 /// Writes out all the relevant mappings for a Rust struct, deferring to writeln_opaque to generate
455 /// the struct itself, and then writing getters and setters for public, understood-type fields and
456 /// a constructor if every field is public.
457 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) {
458 let struct_name = &format!("{}", s.ident);
459 let export = export_status(&s.attrs);
461 ExportStatus::Export => {},
462 ExportStatus::TestOnly => return,
463 ExportStatus::NoExport => {
464 types.struct_ignored(&s.ident);
469 writeln_opaque(w, &s.ident, struct_name, &s.generics, &s.attrs, types, extra_headers, cpp_headers);
471 eprintln!("exporting fields for {}", struct_name);
472 if let syn::Fields::Named(fields) = &s.fields {
473 let mut gen_types = GenericTypes::new();
474 assert!(gen_types.learn_generics(&s.generics, types));
476 let mut all_fields_settable = true;
477 for field in fields.named.iter() {
478 if let syn::Visibility::Public(_) = field.vis {
479 let export = export_status(&field.attrs);
481 ExportStatus::Export => {},
482 ExportStatus::NoExport|ExportStatus::TestOnly => {
483 all_fields_settable = false;
488 if let Some(ident) = &field.ident {
489 let ref_type = syn::Type::Reference(syn::TypeReference {
490 and_token: syn::Token!(&)(Span::call_site()), lifetime: None, mutability: None,
491 elem: Box::new(field.ty.clone()) });
492 if types.understood_c_type(&ref_type, Some(&gen_types)) {
493 writeln_docs(w, &field.attrs, "");
494 write!(w, "#[no_mangle]\npub extern \"C\" fn {}_get_{}(this_ptr: &{}) -> ", struct_name, ident, struct_name).unwrap();
495 types.write_c_type(w, &ref_type, Some(&gen_types), true);
496 write!(w, " {{\n\tlet mut inner_val = &mut unsafe {{ &mut *this_ptr.inner }}.{};\n\t", ident).unwrap();
497 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);
498 if local_var { write!(w, "\n\t").unwrap(); }
499 types.write_to_c_conversion_inline_prefix(w, &ref_type, Some(&gen_types), true);
501 write!(w, "inner_val").unwrap();
503 write!(w, "(*inner_val)").unwrap();
505 types.write_to_c_conversion_inline_suffix(w, &ref_type, Some(&gen_types), true);
506 writeln!(w, "\n}}").unwrap();
509 if types.understood_c_type(&field.ty, Some(&gen_types)) {
510 writeln_docs(w, &field.attrs, "");
511 write!(w, "#[no_mangle]\npub extern \"C\" fn {}_set_{}(this_ptr: &mut {}, mut val: ", struct_name, ident, struct_name).unwrap();
512 types.write_c_type(w, &field.ty, Some(&gen_types), false);
513 write!(w, ") {{\n\t").unwrap();
514 let local_var = types.write_from_c_conversion_new_var(w, &syn::Ident::new("val", Span::call_site()), &field.ty, Some(&gen_types));
515 if local_var { write!(w, "\n\t").unwrap(); }
516 write!(w, "unsafe {{ &mut *this_ptr.inner }}.{} = ", ident).unwrap();
517 types.write_from_c_conversion_prefix(w, &field.ty, Some(&gen_types));
518 write!(w, "val").unwrap();
519 types.write_from_c_conversion_suffix(w, &field.ty, Some(&gen_types));
520 writeln!(w, ";\n}}").unwrap();
521 } else { all_fields_settable = false; }
522 } else { all_fields_settable = false; }
523 } else { all_fields_settable = false; }
526 if all_fields_settable {
527 // Build a constructor!
528 write!(w, "#[must_use]\n#[no_mangle]\npub extern \"C\" fn {}_new(", struct_name).unwrap();
529 for (idx, field) in fields.named.iter().enumerate() {
530 if idx != 0 { write!(w, ", ").unwrap(); }
531 write!(w, "mut {}_arg: ", field.ident.as_ref().unwrap()).unwrap();
532 types.write_c_type(w, &field.ty, Some(&gen_types), false);
534 write!(w, ") -> {} {{\n\t", struct_name).unwrap();
535 for field in fields.named.iter() {
536 let field_name = format!("{}_arg", field.ident.as_ref().unwrap());
537 if types.write_from_c_conversion_new_var(w, &syn::Ident::new(&field_name, Span::call_site()), &field.ty, Some(&gen_types)) {
538 write!(w, "\n\t").unwrap();
541 writeln!(w, "{} {{ inner: Box::into_raw(Box::new(native{} {{", struct_name, s.ident).unwrap();
542 for field in fields.named.iter() {
543 write!(w, "\t\t{}: ", field.ident.as_ref().unwrap()).unwrap();
544 types.write_from_c_conversion_prefix(w, &field.ty, Some(&gen_types));
545 write!(w, "{}_arg", field.ident.as_ref().unwrap()).unwrap();
546 types.write_from_c_conversion_suffix(w, &field.ty, Some(&gen_types));
547 writeln!(w, ",").unwrap();
549 writeln!(w, "\t}})), is_owned: true }}\n}}").unwrap();
553 types.struct_imported(&s.ident, struct_name.clone());
556 /// Prints a relevant conversion for impl *
558 /// For simple impl Struct {}s, this just outputs the wrapper functions as Struct_fn_name() { .. }.
560 /// For impl Trait for Struct{}s, this non-exported generates wrapper functions as
561 /// Trait_Struct_fn_name and a Struct_as_Trait(&struct) -> Trait function which returns a populated
562 /// Trait struct containing a pointer to the passed struct's inner field and the wrapper functions.
564 /// A few non-crate Traits are hard-coded including Default.
565 fn writeln_impl<W: std::io::Write>(w: &mut W, i: &syn::ItemImpl, types: &mut TypeResolver) {
566 if let &syn::Type::Path(ref p) = &*i.self_ty {
567 if p.qself.is_some() { unimplemented!(); }
568 if let Some(ident) = single_ident_generic_path_to_ident(&p.path) {
569 if let Some(resolved_path) = types.maybe_resolve_non_ignored_ident(&ident) {
570 let mut gen_types = GenericTypes::new();
571 if !gen_types.learn_generics(&i.generics, types) {
572 eprintln!("Not implementing anything for impl {} due to not understood generics", ident);
576 if i.defaultness.is_some() || i.unsafety.is_some() { unimplemented!(); }
577 if let Some(trait_path) = i.trait_.as_ref() {
578 if trait_path.0.is_some() { unimplemented!(); }
579 if types.understood_c_path(&trait_path.1) {
580 let full_trait_path = types.resolve_path(&trait_path.1, None);
581 let trait_obj = *types.crate_types.traits.get(&full_trait_path).unwrap();
582 // We learn the associated types maping from the original trait object.
583 // That's great, except that they are unresolved idents, so if we learn
584 // mappings from a trai defined in a different file, we may mis-resolve or
585 // fail to resolve the mapped types.
586 gen_types.learn_associated_types(trait_obj, types);
587 let mut impl_associated_types = HashMap::new();
588 for item in i.items.iter() {
590 syn::ImplItem::Type(t) => {
591 if let syn::Type::Path(p) = &t.ty {
592 if let Some(id) = single_ident_generic_path_to_ident(&p.path) {
593 impl_associated_types.insert(&t.ident, id);
601 let export = export_status(&trait_obj.attrs);
603 ExportStatus::Export => {},
604 ExportStatus::NoExport|ExportStatus::TestOnly => return,
607 // For cases where we have a concrete native object which implements a
608 // trait and need to return the C-mapped version of the trait, provide a
609 // From<> implementation which does all the work to ensure free is handled
610 // properly. This way we can call this method from deep in the
611 // type-conversion logic without actually knowing the concrete native type.
612 writeln!(w, "impl From<native{}> for crate::{} {{", ident, full_trait_path).unwrap();
613 writeln!(w, "\tfn from(obj: native{}) -> Self {{", ident).unwrap();
614 writeln!(w, "\t\tlet mut rust_obj = {} {{ inner: Box::into_raw(Box::new(obj)), is_owned: true }};", ident).unwrap();
615 writeln!(w, "\t\tlet mut ret = {}_as_{}(&rust_obj);", ident, trait_obj.ident).unwrap();
616 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();
617 writeln!(w, "\t\trust_obj.inner = std::ptr::null_mut();").unwrap();
618 writeln!(w, "\t\tret.free = Some({}_free_void);", ident).unwrap();
619 writeln!(w, "\t\tret\n\t}}\n}}").unwrap();
621 write!(w, "#[no_mangle]\npub extern \"C\" fn {}_as_{}(this_arg: *const {}) -> crate::{} {{\n", ident, trait_obj.ident, ident, full_trait_path).unwrap();
622 writeln!(w, "\tcrate::{} {{", full_trait_path).unwrap();
623 writeln!(w, "\t\tthis_arg: unsafe {{ (*this_arg).inner as *mut c_void }},").unwrap();
624 writeln!(w, "\t\tfree: None,").unwrap();
626 macro_rules! write_meth {
627 ($m: expr, $trait: expr, $indent: expr) => {
628 let trait_method = $trait.items.iter().filter_map(|item| {
629 if let syn::TraitItem::Method(t_m) = item { Some(t_m) } else { None }
630 }).find(|trait_meth| trait_meth.sig.ident == $m.sig.ident).unwrap();
631 match export_status(&trait_method.attrs) {
632 ExportStatus::Export => {},
633 ExportStatus::NoExport => {
634 write!(w, "{}\t\t//XXX: Need to export {}\n", $indent, $m.sig.ident).unwrap();
637 ExportStatus::TestOnly => continue,
640 let mut printed = false;
641 if let syn::ReturnType::Type(_, rtype) = &$m.sig.output {
642 if let syn::Type::Reference(r) = &**rtype {
643 write!(w, "\n\t\t{}{}: ", $indent, $m.sig.ident).unwrap();
644 types.write_empty_rust_val(Some(&gen_types), w, &*r.elem);
645 writeln!(w, ",\n{}\t\tset_{}: Some({}_{}_set_{}),", $indent, $m.sig.ident, ident, trait_obj.ident, $m.sig.ident).unwrap();
650 write!(w, "{}\t\t{}: {}_{}_{},\n", $indent, $m.sig.ident, ident, trait_obj.ident, $m.sig.ident).unwrap();
654 for item in trait_obj.items.iter() {
656 syn::TraitItem::Method(m) => {
657 write_meth!(m, trait_obj, "");
662 walk_supertraits!(trait_obj, types, (
664 writeln!(w, "\t\tclone: Some({}_clone_void),", ident).unwrap();
667 if let Some(supertrait_obj) = types.crate_types.traits.get(s) {
668 writeln!(w, "\t\t{}: crate::{} {{", t, s).unwrap();
669 writeln!(w, "\t\t\tthis_arg: unsafe {{ (*this_arg).inner as *mut c_void }},").unwrap();
670 writeln!(w, "\t\t\tfree: None,").unwrap();
671 for item in supertrait_obj.items.iter() {
673 syn::TraitItem::Method(m) => {
674 write_meth!(m, supertrait_obj, "\t");
679 write!(w, "\t\t}},\n").unwrap();
683 write!(w, "\t}}\n}}\nuse {}::{} as {}TraitImport;\n", types.orig_crate, full_trait_path, trait_obj.ident).unwrap();
685 macro_rules! impl_meth {
686 ($m: expr, $trait: expr, $indent: expr) => {
687 let trait_method = $trait.items.iter().filter_map(|item| {
688 if let syn::TraitItem::Method(t_m) = item { Some(t_m) } else { None }
689 }).find(|trait_meth| trait_meth.sig.ident == $m.sig.ident).unwrap();
690 match export_status(&trait_method.attrs) {
691 ExportStatus::Export => {},
692 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
695 if let syn::ReturnType::Type(_, _) = &$m.sig.output {
696 writeln!(w, "#[must_use]").unwrap();
698 write!(w, "extern \"C\" fn {}_{}_{}(", ident, trait_obj.ident, $m.sig.ident).unwrap();
699 gen_types.push_ctx();
700 assert!(gen_types.learn_generics(&$m.sig.generics, types));
701 write_method_params(w, &$m.sig, "c_void", types, Some(&gen_types), true, true);
702 write!(w, " {{\n\t").unwrap();
703 write_method_var_decl_body(w, &$m.sig, "", types, Some(&gen_types), false);
704 let mut takes_self = false;
705 for inp in $m.sig.inputs.iter() {
706 if let syn::FnArg::Receiver(_) = inp {
711 write!(w, "unsafe {{ &mut *(this_arg as *mut native{}) }}.{}(", ident, $m.sig.ident).unwrap();
713 write!(w, "{}::{}::{}(", types.orig_crate, resolved_path, $m.sig.ident).unwrap();
716 let mut real_type = "".to_string();
717 match &$m.sig.output {
718 syn::ReturnType::Type(_, rtype) => {
719 if let Some(mut remaining_path) = first_seg_self(&*rtype) {
720 if let Some(associated_seg) = get_single_remaining_path_seg(&mut remaining_path) {
721 real_type = format!("{}", impl_associated_types.get(associated_seg).unwrap());
727 write_method_call_params(w, &$m.sig, "", types, Some(&gen_types), &real_type, false);
729 write!(w, "\n}}\n").unwrap();
730 if let syn::ReturnType::Type(_, rtype) = &$m.sig.output {
731 if let syn::Type::Reference(r) = &**rtype {
732 assert_eq!($m.sig.inputs.len(), 1); // Must only take self
733 writeln!(w, "extern \"C\" fn {}_{}_set_{}(trait_self_arg: &{}) {{", ident, trait_obj.ident, $m.sig.ident, trait_obj.ident).unwrap();
734 writeln!(w, "\t// This is a bit race-y in the general case, but for our specific use-cases today, we're safe").unwrap();
735 writeln!(w, "\t// Specifically, we must ensure that the first time we're called it can never be in parallel").unwrap();
736 write!(w, "\tif ").unwrap();
737 types.write_empty_rust_val_check(Some(&gen_types), w, &*r.elem, &format!("trait_self_arg.{}", $m.sig.ident));
738 writeln!(w, " {{").unwrap();
739 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();
740 writeln!(w, "\t}}").unwrap();
741 writeln!(w, "}}").unwrap();
747 for item in i.items.iter() {
749 syn::ImplItem::Method(m) => {
750 impl_meth!(m, trait_obj, "");
752 syn::ImplItem::Type(_) => {},
753 _ => unimplemented!(),
756 walk_supertraits!(trait_obj, types, (
758 if let Some(supertrait_obj) = types.crate_types.traits.get(s).cloned() {
759 writeln!(w, "use {}::{} as native{}Trait;", types.orig_crate, s, t).unwrap();
760 for item in supertrait_obj.items.iter() {
762 syn::TraitItem::Method(m) => {
763 impl_meth!(m, supertrait_obj, "\t");
771 write!(w, "\n").unwrap();
772 } else if let Some(trait_ident) = trait_path.1.get_ident() {
773 //XXX: implement for other things like ToString
774 match &format!("{}", trait_ident) as &str {
777 write!(w, "#[must_use]\n#[no_mangle]\npub extern \"C\" fn {}_default() -> {} {{\n", ident, ident).unwrap();
778 write!(w, "\t{} {{ inner: Box::into_raw(Box::new(Default::default())), is_owned: true }}\n", ident).unwrap();
779 write!(w, "}}\n").unwrap();
782 // If we have no generics, try a manual implementation:
783 _ if p.path.get_ident().is_some() => maybe_convert_trait_impl(w, &trait_path.1, &ident, types),
786 } else if p.path.get_ident().is_some() {
787 // If we have no generics, try a manual implementation:
788 maybe_convert_trait_impl(w, &trait_path.1, &ident, types);
791 let declared_type = (*types.get_declared_type(&ident).unwrap()).clone();
792 for item in i.items.iter() {
794 syn::ImplItem::Method(m) => {
795 if let syn::Visibility::Public(_) = m.vis {
796 match export_status(&m.attrs) {
797 ExportStatus::Export => {},
798 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
800 if m.defaultness.is_some() { unimplemented!(); }
801 writeln_docs(w, &m.attrs, "");
802 if let syn::ReturnType::Type(_, _) = &m.sig.output {
803 writeln!(w, "#[must_use]").unwrap();
805 write!(w, "#[no_mangle]\npub extern \"C\" fn {}_{}(", ident, m.sig.ident).unwrap();
806 let ret_type = match &declared_type {
807 DeclType::MirroredEnum => format!("{}", ident),
808 DeclType::StructImported => format!("{}", ident),
809 _ => unimplemented!(),
811 gen_types.push_ctx();
812 assert!(gen_types.learn_generics(&m.sig.generics, types));
813 write_method_params(w, &m.sig, &ret_type, types, Some(&gen_types), false, true);
814 write!(w, " {{\n\t").unwrap();
815 write_method_var_decl_body(w, &m.sig, "", types, Some(&gen_types), false);
816 let mut takes_self = false;
817 let mut takes_mut_self = false;
818 for inp in m.sig.inputs.iter() {
819 if let syn::FnArg::Receiver(r) = inp {
821 if r.mutability.is_some() { takes_mut_self = true; }
825 write!(w, "unsafe {{ &mut (*(this_arg.inner as *mut native{})) }}.{}(", ident, m.sig.ident).unwrap();
826 } else if takes_self {
827 write!(w, "unsafe {{ &*this_arg.inner }}.{}(", m.sig.ident).unwrap();
829 write!(w, "{}::{}::{}(", types.orig_crate, resolved_path, m.sig.ident).unwrap();
831 write_method_call_params(w, &m.sig, "", types, Some(&gen_types), &ret_type, false);
833 writeln!(w, "\n}}\n").unwrap();
841 eprintln!("Not implementing anything for {} due to no-resolve (probably the type isn't pub or its marked not exported)", ident);
847 /// Returns true if the enum will be mapped as an opaue (ie struct with a pointer to the underlying
848 /// type), otherwise it is mapped into a transparent, C-compatible version of itself.
849 fn is_enum_opaque(e: &syn::ItemEnum) -> bool {
850 for var in e.variants.iter() {
851 if let syn::Fields::Unit = var.fields {
852 } else if let syn::Fields::Named(fields) = &var.fields {
853 for field in fields.named.iter() {
854 match export_status(&field.attrs) {
855 ExportStatus::Export|ExportStatus::TestOnly => {},
856 ExportStatus::NoExport => return true,
866 /// Print a mapping of an enum. If all of the enum's fields are C-mapped in some form (or the enum
867 /// is unitary), we generate an equivalent enum with all types replaced with their C mapped
868 /// versions followed by conversion functions which map between the Rust version and the C mapped
870 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) {
871 match export_status(&e.attrs) {
872 ExportStatus::Export => {},
873 ExportStatus::NoExport|ExportStatus::TestOnly => return,
876 if is_enum_opaque(e) {
877 eprintln!("Skipping enum {} as it contains non-unit fields", e.ident);
878 writeln_opaque(w, &e.ident, &format!("{}", e.ident), &e.generics, &e.attrs, types, extra_headers, cpp_headers);
879 types.enum_ignored(&e.ident);
882 writeln_docs(w, &e.attrs, "");
884 if e.generics.lt_token.is_some() {
887 types.mirrored_enum_declared(&e.ident);
889 let mut needs_free = false;
891 writeln!(w, "#[must_use]\n#[derive(Clone)]\n#[repr(C)]\npub enum {} {{", e.ident).unwrap();
892 for var in e.variants.iter() {
893 assert_eq!(export_status(&var.attrs), ExportStatus::Export); // We can't partially-export a mirrored enum
894 writeln_docs(w, &var.attrs, "\t");
895 write!(w, "\t{}", var.ident).unwrap();
896 if let syn::Fields::Named(fields) = &var.fields {
898 writeln!(w, " {{").unwrap();
899 for field in fields.named.iter() {
900 if export_status(&field.attrs) == ExportStatus::TestOnly { continue; }
901 write!(w, "\t\t{}: ", field.ident.as_ref().unwrap()).unwrap();
902 types.write_c_type(w, &field.ty, None, false);
903 writeln!(w, ",").unwrap();
905 write!(w, "\t}}").unwrap();
907 if var.discriminant.is_some() { unimplemented!(); }
908 writeln!(w, ",").unwrap();
910 writeln!(w, "}}\nuse {}::{}::{} as native{};\nimpl {} {{", types.orig_crate, types.module_path, e.ident, e.ident, e.ident).unwrap();
912 macro_rules! write_conv {
913 ($fn_sig: expr, $to_c: expr, $ref: expr) => {
914 writeln!(w, "\t#[allow(unused)]\n\tpub(crate) fn {} {{\n\t\tmatch {} {{", $fn_sig, if $to_c { "native" } else { "self" }).unwrap();
915 for var in e.variants.iter() {
916 write!(w, "\t\t\t{}{}::{} ", if $to_c { "native" } else { "" }, e.ident, var.ident).unwrap();
917 if let syn::Fields::Named(fields) = &var.fields {
918 write!(w, "{{").unwrap();
919 for field in fields.named.iter() {
920 if export_status(&field.attrs) == ExportStatus::TestOnly { continue; }
921 write!(w, "{}{}, ", if $ref { "ref " } else { "mut " }, field.ident.as_ref().unwrap()).unwrap();
923 write!(w, "}} ").unwrap();
925 write!(w, "=>").unwrap();
926 if let syn::Fields::Named(fields) = &var.fields {
927 write!(w, " {{\n\t\t\t\t").unwrap();
928 for field in fields.named.iter() {
929 if export_status(&field.attrs) == ExportStatus::TestOnly { continue; }
930 let mut sink = ::std::io::sink();
931 let mut out: &mut dyn std::io::Write = if $ref { &mut sink } else { w };
932 let new_var = if $to_c {
933 types.write_to_c_conversion_new_var(&mut out, field.ident.as_ref().unwrap(), &field.ty, None, false)
935 types.write_from_c_conversion_new_var(&mut out, field.ident.as_ref().unwrap(), &field.ty, None)
939 write!(w, "let mut {}_nonref = (*{}).clone();\n\t\t\t\t", field.ident.as_ref().unwrap(), field.ident.as_ref().unwrap()).unwrap();
941 let nonref_ident = syn::Ident::new(&format!("{}_nonref", field.ident.as_ref().unwrap()), Span::call_site());
943 types.write_to_c_conversion_new_var(w, &nonref_ident, &field.ty, None, false);
945 types.write_from_c_conversion_new_var(w, &nonref_ident, &field.ty, None);
947 write!(w, "\n\t\t\t\t").unwrap();
950 write!(w, "\n\t\t\t\t").unwrap();
954 } else { write!(w, " ").unwrap(); }
955 write!(w, "{}{}::{}", if $to_c { "" } else { "native" }, e.ident, var.ident).unwrap();
956 if let syn::Fields::Named(fields) = &var.fields {
957 write!(w, " {{").unwrap();
958 for field in fields.named.iter() {
959 if export_status(&field.attrs) == ExportStatus::TestOnly { continue; }
960 write!(w, "\n\t\t\t\t\t{}: ", field.ident.as_ref().unwrap()).unwrap();
962 types.write_to_c_conversion_inline_prefix(w, &field.ty, None, false);
964 types.write_from_c_conversion_prefix(w, &field.ty, None);
967 field.ident.as_ref().unwrap(),
968 if $ref { "_nonref" } else { "" }).unwrap();
970 types.write_to_c_conversion_inline_suffix(w, &field.ty, None, false);
972 types.write_from_c_conversion_suffix(w, &field.ty, None);
974 write!(w, ",").unwrap();
976 writeln!(w, "\n\t\t\t\t}}").unwrap();
977 write!(w, "\t\t\t}}").unwrap();
979 writeln!(w, ",").unwrap();
981 writeln!(w, "\t\t}}\n\t}}").unwrap();
985 write_conv!(format!("to_native(&self) -> native{}", e.ident), false, true);
986 write_conv!(format!("into_native(self) -> native{}", e.ident), false, false);
987 write_conv!(format!("from_native(native: &native{}) -> Self", e.ident), true, true);
988 write_conv!(format!("native_into(native: native{}) -> Self", e.ident), true, false);
989 writeln!(w, "}}").unwrap();
992 writeln!(w, "#[no_mangle]\npub extern \"C\" fn {}_free(this_ptr: {}) {{ }}", e.ident, e.ident).unwrap();
994 writeln!(w, "#[no_mangle]").unwrap();
995 writeln!(w, "pub extern \"C\" fn {}_clone(orig: &{}) -> {} {{", e.ident, e.ident, e.ident).unwrap();
996 writeln!(w, "\torig.clone()").unwrap();
997 writeln!(w, "}}").unwrap();
998 write_cpp_wrapper(cpp_headers, &format!("{}", e.ident), needs_free);
1001 fn writeln_fn<'a, 'b, W: std::io::Write>(w: &mut W, f: &'a syn::ItemFn, types: &mut TypeResolver<'b, 'a>) {
1002 match export_status(&f.attrs) {
1003 ExportStatus::Export => {},
1004 ExportStatus::NoExport|ExportStatus::TestOnly => return,
1006 writeln_docs(w, &f.attrs, "");
1008 let mut gen_types = GenericTypes::new();
1009 if !gen_types.learn_generics(&f.sig.generics, types) { return; }
1011 write!(w, "#[no_mangle]\npub extern \"C\" fn {}(", f.sig.ident).unwrap();
1012 write_method_params(w, &f.sig, "", types, Some(&gen_types), false, true);
1013 write!(w, " {{\n\t").unwrap();
1014 write_method_var_decl_body(w, &f.sig, "", types, Some(&gen_types), false);
1015 write!(w, "{}::{}::{}(", types.orig_crate, types.module_path, f.sig.ident).unwrap();
1016 write_method_call_params(w, &f.sig, "", types, Some(&gen_types), "", false);
1017 writeln!(w, "\n}}\n").unwrap();
1020 // ********************************
1021 // *** File/Crate Walking Logic ***
1022 // ********************************
1024 /// Simple utility to walk the modules in a crate - iterating over the modules (with file paths) in
1026 struct FileIter<'a, I: Iterator<Item = &'a syn::Item>> {
1032 impl<'a, I: Iterator<Item = &'a syn::Item>> Iterator for FileIter<'a, I> {
1033 type Item = (String, String, &'a syn::ItemMod);
1034 fn next(&mut self) -> std::option::Option<<Self as std::iter::Iterator>::Item> {
1036 match self.item_iter.next() {
1037 Some(syn::Item::Mod(m)) => {
1038 if let syn::Visibility::Public(_) = m.vis {
1039 match export_status(&m.attrs) {
1040 ExportStatus::Export => {},
1041 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1044 let f_path = format!("{}/{}.rs", (self.path.as_ref() as &Path).parent().unwrap().display(), m.ident);
1045 let new_mod = if self.module.is_empty() { format!("{}", m.ident) } else { format!("{}::{}", self.module, m.ident) };
1046 if let Ok(_) = File::open(&format!("{}/{}", self.in_dir, f_path)) {
1047 return Some((f_path, new_mod, m));
1050 format!("{}/{}/mod.rs", (self.path.as_ref() as &Path).parent().unwrap().display(), m.ident),
1056 None => return None,
1061 fn file_iter<'a>(file: &'a syn::File, in_dir: &'a str, path: &'a str, module: &'a str) ->
1062 impl Iterator<Item = (String, String, &'a syn::ItemMod)> + 'a {
1063 FileIter { in_dir, path, module, item_iter: file.items.iter() }
1066 /// A struct containing the syn::File AST for each file in the crate.
1067 struct FullLibraryAST {
1068 files: HashMap<String, syn::File>,
1071 /// Do the Real Work of mapping an original file to C-callable wrappers. Creates a new file at
1072 /// `out_path` and fills it with wrapper structs/functions to allow calling the things in the AST
1073 /// at `module` from C.
1074 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) {
1075 let syntax = if let Some(ast) = libast.files.get(module) { ast } else { return };
1077 assert!(syntax.shebang.is_none()); // Not sure what this is, hope we dont have one
1079 let new_file_path = format!("{}/{}", out_dir, path);
1080 let _ = std::fs::create_dir((&new_file_path.as_ref() as &std::path::Path).parent().unwrap());
1081 let mut out = std::fs::OpenOptions::new().write(true).create(true).truncate(true)
1082 .open(new_file_path).expect("Unable to open new src file");
1084 assert_eq!(export_status(&syntax.attrs), ExportStatus::Export);
1085 writeln_docs(&mut out, &syntax.attrs, "");
1087 if path.ends_with("/lib.rs") {
1088 // Special-case the top-level lib.rs with various lint allows and a pointer to the c_types
1089 // and bitcoin hand-written modules.
1090 writeln!(out, "#![allow(unknown_lints)]").unwrap();
1091 writeln!(out, "#![allow(non_camel_case_types)]").unwrap();
1092 writeln!(out, "#![allow(non_snake_case)]").unwrap();
1093 writeln!(out, "#![allow(unused_imports)]").unwrap();
1094 writeln!(out, "#![allow(unused_variables)]").unwrap();
1095 writeln!(out, "#![allow(unused_mut)]").unwrap();
1096 writeln!(out, "#![allow(unused_parens)]").unwrap();
1097 writeln!(out, "#![allow(unused_unsafe)]").unwrap();
1098 writeln!(out, "#![allow(unused_braces)]").unwrap();
1099 writeln!(out, "mod c_types;").unwrap();
1100 writeln!(out, "mod bitcoin;").unwrap();
1102 writeln!(out, "\nuse std::ffi::c_void;\nuse bitcoin::hashes::Hash;\nuse crate::c_types::*;\n").unwrap();
1105 for (path, new_mod, m) in file_iter(&syntax, in_dir, path, &module) {
1106 writeln_docs(&mut out, &m.attrs, "");
1107 writeln!(out, "pub mod {};", m.ident).unwrap();
1108 convert_file(libast, crate_types, in_dir, out_dir, &path,
1109 orig_crate, &new_mod, header_file, cpp_header_file);
1112 eprintln!("Converting {} entries...", path);
1114 let mut type_resolver = TypeResolver::new(orig_crate, module, crate_types);
1116 for item in syntax.items.iter() {
1118 syn::Item::Use(u) => type_resolver.process_use(&mut out, &u),
1119 syn::Item::Static(_) => {},
1120 syn::Item::Enum(e) => {
1121 if let syn::Visibility::Public(_) = e.vis {
1122 writeln_enum(&mut out, &e, &mut type_resolver, header_file, cpp_header_file);
1125 syn::Item::Impl(i) => {
1126 writeln_impl(&mut out, &i, &mut type_resolver);
1128 syn::Item::Struct(s) => {
1129 if let syn::Visibility::Public(_) = s.vis {
1130 writeln_struct(&mut out, &s, &mut type_resolver, header_file, cpp_header_file);
1133 syn::Item::Trait(t) => {
1134 if let syn::Visibility::Public(_) = t.vis {
1135 writeln_trait(&mut out, &t, &mut type_resolver, header_file, cpp_header_file);
1138 syn::Item::Mod(_) => {}, // We don't have to do anything - the top loop handles these.
1139 syn::Item::Const(c) => {
1140 // Re-export any primitive-type constants.
1141 if let syn::Visibility::Public(_) = c.vis {
1142 if let syn::Type::Path(p) = &*c.ty {
1143 let resolved_path = type_resolver.resolve_path(&p.path, None);
1144 if type_resolver.is_primitive(&resolved_path) {
1145 writeln!(out, "\n#[no_mangle]").unwrap();
1146 writeln!(out, "pub static {}: {} = {}::{}::{};", c.ident, resolved_path, orig_crate, module, c.ident).unwrap();
1151 syn::Item::Type(t) => {
1152 if let syn::Visibility::Public(_) = t.vis {
1153 match export_status(&t.attrs) {
1154 ExportStatus::Export => {},
1155 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1158 let mut process_alias = true;
1159 for tok in t.generics.params.iter() {
1160 if let syn::GenericParam::Lifetime(_) = tok {}
1161 else { process_alias = false; }
1165 syn::Type::Path(_) =>
1166 writeln_opaque(&mut out, &t.ident, &format!("{}", t.ident), &t.generics, &t.attrs, &type_resolver, header_file, cpp_header_file),
1172 syn::Item::Fn(f) => {
1173 if let syn::Visibility::Public(_) = f.vis {
1174 writeln_fn(&mut out, &f, &mut type_resolver);
1177 syn::Item::Macro(m) => {
1178 if m.ident.is_none() { // If its not a macro definition
1179 convert_macro(&mut out, &m.mac.path, &m.mac.tokens, &type_resolver);
1182 syn::Item::Verbatim(_) => {},
1183 syn::Item::ExternCrate(_) => {},
1184 _ => unimplemented!(),
1188 out.flush().unwrap();
1191 /// Load the AST for each file in the crate, filling the FullLibraryAST object
1192 fn load_ast(in_dir: &str, path: &str, module: String, ast_storage: &mut FullLibraryAST) {
1193 eprintln!("Loading {}{}...", in_dir, path);
1195 let mut file = File::open(format!("{}/{}", in_dir, path)).expect("Unable to open file");
1196 let mut src = String::new();
1197 file.read_to_string(&mut src).expect("Unable to read file");
1198 let syntax = syn::parse_file(&src).expect("Unable to parse file");
1200 assert_eq!(export_status(&syntax.attrs), ExportStatus::Export);
1202 for (path, new_mod, _) in file_iter(&syntax, in_dir, path, &module) {
1203 load_ast(in_dir, &path, new_mod, ast_storage);
1205 ast_storage.files.insert(module, syntax);
1208 /// Insert ident -> absolute Path resolutions into imports from the given UseTree and path-prefix.
1209 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>) {
1211 syn::UseTree::Path(p) => {
1212 path.push(syn::PathSegment { ident: p.ident.clone(), arguments: syn::PathArguments::None });
1213 process_use_intern(&p.tree, path, imports);
1215 syn::UseTree::Name(n) => {
1216 path.push(syn::PathSegment { ident: n.ident.clone(), arguments: syn::PathArguments::None });
1217 imports.insert(&n.ident, syn::Path { leading_colon: Some(syn::Token![::](Span::call_site())), segments: path });
1219 syn::UseTree::Group(g) => {
1220 for i in g.items.iter() {
1221 process_use_intern(i, path.clone(), imports);
1228 /// Map all the Paths in a Type into absolute paths given a set of imports (generated via process_use_intern)
1229 fn resolve_imported_refs(imports: &HashMap<&syn::Ident, syn::Path>, mut ty: syn::Type) -> syn::Type {
1231 syn::Type::Path(p) => {
1232 if let Some(ident) = p.path.get_ident() {
1233 if let Some(newpath) = imports.get(ident) {
1234 p.path = newpath.clone();
1236 } else { unimplemented!(); }
1238 syn::Type::Reference(r) => {
1239 r.elem = Box::new(resolve_imported_refs(imports, (*r.elem).clone()));
1241 syn::Type::Slice(s) => {
1242 s.elem = Box::new(resolve_imported_refs(imports, (*s.elem).clone()));
1244 syn::Type::Tuple(t) => {
1245 for e in t.elems.iter_mut() {
1246 *e = resolve_imported_refs(imports, e.clone());
1249 _ => unimplemented!(),
1254 /// Walk the FullLibraryAST, deciding how things will be mapped and adding tracking to CrateTypes.
1255 fn walk_ast<'a>(in_dir: &str, path: &str, module: String, ast_storage: &'a FullLibraryAST, crate_types: &mut CrateTypes<'a>) {
1256 let syntax = if let Some(ast) = ast_storage.files.get(&module) { ast } else { return };
1257 assert_eq!(export_status(&syntax.attrs), ExportStatus::Export);
1259 for (path, new_mod, _) in file_iter(&syntax, in_dir, path, &module) {
1260 walk_ast(in_dir, &path, new_mod, ast_storage, crate_types);
1263 let mut import_maps = HashMap::new();
1265 for item in syntax.items.iter() {
1267 syn::Item::Use(u) => {
1268 process_use_intern(&u.tree, syn::punctuated::Punctuated::new(), &mut import_maps);
1270 syn::Item::Struct(s) => {
1271 if let syn::Visibility::Public(_) = s.vis {
1272 match export_status(&s.attrs) {
1273 ExportStatus::Export => {},
1274 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1276 let struct_path = format!("{}::{}", module, s.ident);
1277 crate_types.opaques.insert(struct_path, &s.ident);
1280 syn::Item::Trait(t) => {
1281 if let syn::Visibility::Public(_) = t.vis {
1282 match export_status(&t.attrs) {
1283 ExportStatus::Export => {},
1284 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1286 let trait_path = format!("{}::{}", module, t.ident);
1287 crate_types.traits.insert(trait_path, &t);
1290 syn::Item::Type(t) => {
1291 if let syn::Visibility::Public(_) = t.vis {
1292 match export_status(&t.attrs) {
1293 ExportStatus::Export => {},
1294 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1296 let type_path = format!("{}::{}", module, t.ident);
1297 let mut process_alias = true;
1298 for tok in t.generics.params.iter() {
1299 if let syn::GenericParam::Lifetime(_) = tok {}
1300 else { process_alias = false; }
1304 syn::Type::Path(_) => {
1305 // If its a path with no generics, assume we don't map the aliased type and map it opaque
1306 crate_types.opaques.insert(type_path, &t.ident);
1309 crate_types.type_aliases.insert(type_path, resolve_imported_refs(&import_maps, (*t.ty).clone()));
1315 syn::Item::Enum(e) if is_enum_opaque(e) => {
1316 if let syn::Visibility::Public(_) = e.vis {
1317 match export_status(&e.attrs) {
1318 ExportStatus::Export => {},
1319 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1321 let enum_path = format!("{}::{}", module, e.ident);
1322 crate_types.opaques.insert(enum_path, &e.ident);
1325 syn::Item::Enum(e) => {
1326 if let syn::Visibility::Public(_) = e.vis {
1327 match export_status(&e.attrs) {
1328 ExportStatus::Export => {},
1329 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1331 let enum_path = format!("{}::{}", module, e.ident);
1332 crate_types.mirrored_enums.insert(enum_path, &e);
1341 let args: Vec<String> = env::args().collect();
1342 if args.len() != 7 {
1343 eprintln!("Usage: source/dir target/dir source_crate_name derived_templates.rs extra/includes.h extra/cpp/includes.hpp");
1347 let mut derived_templates = std::fs::OpenOptions::new().write(true).create(true).truncate(true)
1348 .open(&args[4]).expect("Unable to open new header file");
1349 let mut header_file = std::fs::OpenOptions::new().write(true).create(true).truncate(true)
1350 .open(&args[5]).expect("Unable to open new header file");
1351 let mut cpp_header_file = std::fs::OpenOptions::new().write(true).create(true).truncate(true)
1352 .open(&args[6]).expect("Unable to open new header file");
1354 writeln!(header_file, "#if defined(__GNUC__)\n#define MUST_USE_STRUCT __attribute__((warn_unused))").unwrap();
1355 writeln!(header_file, "#else\n#define MUST_USE_STRUCT\n#endif").unwrap();
1356 writeln!(header_file, "#if defined(__GNUC__)\n#define MUST_USE_RES __attribute__((warn_unused_result))").unwrap();
1357 writeln!(header_file, "#else\n#define MUST_USE_RES\n#endif").unwrap();
1358 writeln!(cpp_header_file, "#include <string.h>\nnamespace LDK {{").unwrap();
1360 // First parse the full crate's ASTs, caching them so that we can hold references to the AST
1361 // objects in other datastructures:
1362 let mut libast = FullLibraryAST { files: HashMap::new() };
1363 load_ast(&args[1], "/lib.rs", "".to_string(), &mut libast);
1365 // ...then walk the ASTs tracking what types we will map, and how, so that we can resolve them
1366 // when parsing other file ASTs...
1367 let mut libtypes = CrateTypes { traits: HashMap::new(), opaques: HashMap::new(), mirrored_enums: HashMap::new(),
1368 type_aliases: HashMap::new(), templates_defined: HashMap::default(), template_file: &mut derived_templates };
1369 walk_ast(&args[1], "/lib.rs", "".to_string(), &libast, &mut libtypes);
1371 // ... finally, do the actual file conversion/mapping, writing out types as we go.
1372 convert_file(&libast, &mut libtypes, &args[1], &args[2], "/lib.rs", &args[3], "", &mut header_file, &mut cpp_header_file);
1374 // For container templates which we created while walking the crate, make sure we add C++
1375 // mapped types so that C++ users can utilize the auto-destructors available.
1376 for (ty, has_destructor) in libtypes.templates_defined.iter() {
1377 write_cpp_wrapper(&mut cpp_header_file, ty, *has_destructor);
1379 writeln!(cpp_header_file, "}}").unwrap();
1381 header_file.flush().unwrap();
1382 cpp_header_file.flush().unwrap();
1383 derived_templates.flush().unwrap();