1 //! Converts a rust crate into a rust crate containing a number of C-exported wrapper functions and
2 //! classes (which is exportable using cbindgen).
3 //! In general, supports convering:
4 //! * structs as a pointer to the underlying type (either owned or not owned),
5 //! * traits as a void-ptr plus a jump table,
6 //! * enums as an equivalent enum with all the inner fields mapped to the mapped types,
7 //! * certain containers (tuples, slices, Vecs, Options, and Results currently) to a concrete
8 //! version of a defined container template.
10 //! It also generates relevant memory-management functions and free-standing functions with
11 //! parameters mapped.
13 use std::collections::HashMap;
16 use std::io::{Read, Write};
20 use proc_macro2::{TokenTree, TokenStream, Span};
27 // *************************************
28 // *** Manually-expanded conversions ***
29 // *************************************
31 /// Because we don't expand macros, any code that we need to generated based on their contents has
32 /// to be completely manual. In this case its all just serialization, so its not too hard.
33 fn convert_macro<W: std::io::Write>(w: &mut W, macro_path: &syn::Path, stream: &TokenStream, types: &TypeResolver) {
34 assert_eq!(macro_path.segments.len(), 1);
35 match &format!("{}", macro_path.segments.iter().next().unwrap().ident) as &str {
36 "impl_writeable" | "impl_writeable_len_match" => {
37 let struct_for = if let TokenTree::Ident(i) = stream.clone().into_iter().next().unwrap() { i } else { unimplemented!(); };
38 if let Some(s) = types.maybe_resolve_ident(&struct_for) {
39 if !types.crate_types.opaques.get(&s).is_some() { return; }
40 writeln!(w, "#[no_mangle]").unwrap();
41 writeln!(w, "pub extern \"C\" fn {}_write(obj: *const {}) -> crate::c_types::derived::CVec_u8Z {{", struct_for, struct_for).unwrap();
42 writeln!(w, "\tcrate::c_types::serialize_obj(unsafe {{ &(*(*obj).inner) }})").unwrap();
43 writeln!(w, "}}").unwrap();
44 writeln!(w, "#[no_mangle]").unwrap();
45 writeln!(w, "pub extern \"C\" fn {}_read(ser: crate::c_types::u8slice) -> {} {{", struct_for, struct_for).unwrap();
46 writeln!(w, "\tif let Ok(res) = crate::c_types::deserialize_obj(ser) {{").unwrap();
47 writeln!(w, "\t\t{} {{ inner: Box::into_raw(Box::new(res)), is_owned: true }}", struct_for).unwrap();
48 writeln!(w, "\t}} else {{").unwrap();
49 writeln!(w, "\t\t{} {{ inner: std::ptr::null_mut(), is_owned: true }}", struct_for).unwrap();
50 writeln!(w, "\t}}\n}}").unwrap();
57 /// Convert "impl trait_path for for_obj { .. }" for manually-mapped types (ie (de)serialization)
58 fn maybe_convert_trait_impl<W: std::io::Write>(w: &mut W, trait_path: &syn::Path, for_obj: &syn::Ident, types: &TypeResolver) {
59 if let Some(t) = types.maybe_resolve_path(&trait_path, None) {
60 let s = types.maybe_resolve_ident(for_obj).unwrap();
61 if !types.crate_types.opaques.get(&s).is_some() { return; }
63 "util::ser::Writeable" => {
64 writeln!(w, "#[no_mangle]").unwrap();
65 writeln!(w, "pub extern \"C\" fn {}_write(obj: *const {}) -> crate::c_types::derived::CVec_u8Z {{", for_obj, for_obj).unwrap();
66 writeln!(w, "\tcrate::c_types::serialize_obj(unsafe {{ &(*(*obj).inner) }})").unwrap();
67 writeln!(w, "}}").unwrap();
69 "util::ser::Readable" => {
70 writeln!(w, "#[no_mangle]").unwrap();
71 writeln!(w, "pub extern \"C\" fn {}_read(ser: crate::c_types::u8slice) -> {} {{", for_obj, for_obj).unwrap();
72 writeln!(w, "\tif let Ok(res) = crate::c_types::deserialize_obj(ser) {{").unwrap();
73 writeln!(w, "\t\t{} {{ inner: Box::into_raw(Box::new(res)), is_owned: true }}", for_obj).unwrap();
74 writeln!(w, "\t}} else {{").unwrap();
75 writeln!(w, "\t\t{} {{ inner: std::ptr::null_mut(), is_owned: true }}", for_obj).unwrap();
76 writeln!(w, "\t}}\n}}").unwrap();
83 // *******************************
84 // *** Per-Type Printing Logic ***
85 // *******************************
87 macro_rules! walk_supertraits { ($t: expr, $types: expr, ($( $pat: pat => $e: expr),*) ) => { {
88 if $t.colon_token.is_some() {
89 for st in $t.supertraits.iter() {
91 syn::TypeParamBound::Trait(supertrait) => {
92 if supertrait.paren_token.is_some() || supertrait.lifetimes.is_some() {
95 if let Some(ident) = supertrait.path.get_ident() {
96 match (&format!("{}", ident) as &str, &ident) {
100 let path = $types.resolve_path(&supertrait.path, None);
101 match (&path as &str, &supertrait.path.segments.iter().last().unwrap().ident) {
106 syn::TypeParamBound::Lifetime(_) => unimplemented!(),
112 /// Prints a C-mapped trait object containing a void pointer and a jump table for each function in
113 /// the original trait.
114 /// Implements the native Rust trait and relevant parent traits for the new C-mapped trait.
116 /// Finally, implements Deref<MappedTrait> for MappedTrait which allows its use in types which need
117 /// a concrete Deref to the Rust trait.
118 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) {
119 let trait_name = format!("{}", t.ident);
120 match export_status(&t.attrs) {
121 ExportStatus::Export => {},
122 ExportStatus::NoExport|ExportStatus::TestOnly => return,
124 writeln_docs(w, &t.attrs, "");
126 let mut gen_types = GenericTypes::new();
127 assert!(gen_types.learn_generics(&t.generics, types));
128 gen_types.learn_associated_types(&t, types);
130 writeln!(w, "#[repr(C)]\npub struct {} {{", trait_name).unwrap();
131 writeln!(w, "\tpub this_arg: *mut c_void,").unwrap();
132 let mut generated_fields = Vec::new(); // Every field's name except this_arg, used in Clone generation
133 for item in t.items.iter() {
135 &syn::TraitItem::Method(ref m) => {
136 match export_status(&m.attrs) {
137 ExportStatus::NoExport => {
138 // NoExport in this context means we'll hit an unimplemented!() at runtime,
142 ExportStatus::Export => {},
143 ExportStatus::TestOnly => continue,
145 if m.default.is_some() { unimplemented!(); }
147 gen_types.push_ctx();
148 assert!(gen_types.learn_generics(&m.sig.generics, types));
150 writeln_docs(w, &m.attrs, "\t");
152 if let syn::ReturnType::Type(_, rtype) = &m.sig.output {
153 if let syn::Type::Reference(r) = &**rtype {
154 // We have to do quite a dance for trait functions which return references
155 // - they ultimately require us to have a native Rust object stored inside
156 // our concrete trait to return a reference to. However, users may wish to
157 // update the value to be returned each time the function is called (or, to
158 // make C copies of Rust impls equivalent, we have to be able to).
160 // Thus, we store a copy of the C-mapped type (which is just a pointer to
161 // the Rust type and a flag to indicate whether deallocation needs to
162 // happen) as well as provide an Option<>al function pointer which is
163 // called when the trait method is called which allows updating on the fly.
164 write!(w, "\tpub {}: ", m.sig.ident).unwrap();
165 generated_fields.push(format!("{}", m.sig.ident));
166 types.write_c_type(w, &*r.elem, Some(&gen_types), false);
167 writeln!(w, ",").unwrap();
168 writeln!(w, "\t/// Fill in the {} field as a reference to it will be given to Rust after this returns", m.sig.ident).unwrap();
169 writeln!(w, "\t/// Note that this takes a pointer to this object, not the this_ptr like other methods do").unwrap();
170 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();
171 writeln!(w, "\tpub set_{}: Option<extern \"C\" fn(&{})>,", m.sig.ident, trait_name).unwrap();
172 generated_fields.push(format!("set_{}", m.sig.ident));
173 // Note that cbindgen will now generate
174 // typedef struct Thing {..., set_thing: (const Thing*), ...} Thing;
175 // which does not compile since Thing is not defined before it is used.
176 writeln!(extra_headers, "struct LDK{};", trait_name).unwrap();
177 writeln!(extra_headers, "typedef struct LDK{} LDK{};", trait_name, trait_name).unwrap();
181 // Sadly, this currently doesn't do what we want, but it should be easy to get
182 // cbindgen to support it. See https://github.com/eqrion/cbindgen/issues/531
183 writeln!(w, "\t#[must_use]").unwrap();
186 write!(w, "\tpub {}: extern \"C\" fn (", m.sig.ident).unwrap();
187 generated_fields.push(format!("{}", m.sig.ident));
188 write_method_params(w, &m.sig, "c_void", types, Some(&gen_types), true, false);
189 writeln!(w, ",").unwrap();
193 &syn::TraitItem::Type(_) => {},
194 _ => unimplemented!(),
197 // Add functions which may be required for supertrait implementations.
198 walk_supertraits!(t, types, (
200 writeln!(w, "\tpub clone: Option<extern \"C\" fn (this_arg: *const c_void) -> *mut c_void>,").unwrap();
201 generated_fields.push("clone".to_owned());
203 ("std::cmp::Eq", _) => {
204 writeln!(w, "\tpub eq: extern \"C\" fn (this_arg: *const c_void, other_arg: &{}) -> bool,", trait_name).unwrap();
205 writeln!(extra_headers, "typedef struct LDK{} LDK{};", trait_name, trait_name).unwrap();
206 generated_fields.push("eq".to_owned());
208 ("std::hash::Hash", _) => {
209 writeln!(w, "\tpub hash: extern \"C\" fn (this_arg: *const c_void) -> u64,").unwrap();
210 generated_fields.push("hash".to_owned());
212 ("Send", _) => {}, ("Sync", _) => {},
214 // For in-crate supertraits, just store a C-mapped copy of the supertrait as a member.
215 if types.crate_types.traits.get(s).is_none() { unimplemented!(); }
216 writeln!(w, "\tpub {}: crate::{},", i, s).unwrap();
217 generated_fields.push(format!("{}", i));
220 writeln!(w, "\tpub free: Option<extern \"C\" fn(this_arg: *mut c_void)>,").unwrap();
221 generated_fields.push("free".to_owned());
222 writeln!(w, "}}").unwrap();
223 // Implement supertraits for the C-mapped struct.
224 walk_supertraits!(t, types, (
225 ("Send", _) => writeln!(w, "unsafe impl Send for {} {{}}", trait_name).unwrap(),
226 ("Sync", _) => writeln!(w, "unsafe impl Sync for {} {{}}", trait_name).unwrap(),
227 ("std::cmp::Eq", _) => {
228 writeln!(w, "impl std::cmp::Eq for {} {{}}", trait_name).unwrap();
229 writeln!(w, "impl std::cmp::PartialEq for {} {{", trait_name).unwrap();
230 writeln!(w, "\tfn eq(&self, o: &Self) -> bool {{ (self.eq)(self.this_arg, o) }}\n}}").unwrap();
232 ("std::hash::Hash", _) => {
233 writeln!(w, "impl std::hash::Hash for {} {{", trait_name).unwrap();
234 writeln!(w, "\tfn hash<H: std::hash::Hasher>(&self, hasher: &mut H) {{ hasher.write_u64((self.hash)(self.this_arg)) }}\n}}").unwrap();
237 writeln!(w, "#[no_mangle]").unwrap();
238 writeln!(w, "pub extern \"C\" fn {}_clone(orig: &{}) -> {} {{", trait_name, trait_name, trait_name).unwrap();
239 writeln!(w, "\t{} {{", trait_name).unwrap();
240 writeln!(w, "\t\tthis_arg: if let Some(f) = orig.clone {{ (f)(orig.this_arg) }} else {{ orig.this_arg }},").unwrap();
241 for field in generated_fields.iter() {
242 writeln!(w, "\t\t{}: orig.{}.clone(),", field, field).unwrap();
244 writeln!(w, "\t}}\n}}").unwrap();
245 writeln!(w, "impl Clone for {} {{", trait_name).unwrap();
246 writeln!(w, "\tfn clone(&self) -> Self {{").unwrap();
247 writeln!(w, "\t\t{}_clone(self)", trait_name).unwrap();
248 writeln!(w, "\t}}\n}}").unwrap();
251 if s != "util::events::MessageSendEventsProvider" { unimplemented!(); }
252 // XXX: We straight-up cheat here - instead of bothering to get the trait object we
253 // just print what we need since this is only used in one place.
254 writeln!(w, "impl lightning::{} for {} {{", s, trait_name).unwrap();
255 writeln!(w, "\tfn get_and_clear_pending_msg_events(&self) -> Vec<lightning::util::events::MessageSendEvent> {{").unwrap();
256 writeln!(w, "\t\t<crate::{} as lightning::{}>::get_and_clear_pending_msg_events(&self.{})", s, s, i).unwrap();
257 writeln!(w, "\t}}\n}}").unwrap();
261 // Finally, implement the original Rust trait for the newly created mapped trait.
262 writeln!(w, "\nuse {}::{}::{} as rust{};", types.orig_crate, types.module_path, t.ident, trait_name).unwrap();
263 write!(w, "impl rust{}", t.ident).unwrap();
264 maybe_write_generics(w, &t.generics, types, false);
265 writeln!(w, " for {} {{", trait_name).unwrap();
266 for item in t.items.iter() {
268 syn::TraitItem::Method(m) => {
269 if let ExportStatus::TestOnly = export_status(&m.attrs) { continue; }
270 if m.default.is_some() { unimplemented!(); }
271 if m.sig.constness.is_some() || m.sig.asyncness.is_some() || m.sig.unsafety.is_some() ||
272 m.sig.abi.is_some() || m.sig.variadic.is_some() {
275 gen_types.push_ctx();
276 assert!(gen_types.learn_generics(&m.sig.generics, types));
277 write!(w, "\tfn {}", m.sig.ident).unwrap();
278 types.write_rust_generic_param(w, Some(&gen_types), m.sig.generics.params.iter());
279 write!(w, "(").unwrap();
280 for inp in m.sig.inputs.iter() {
282 syn::FnArg::Receiver(recv) => {
283 if !recv.attrs.is_empty() || recv.reference.is_none() { unimplemented!(); }
284 write!(w, "&").unwrap();
285 if let Some(lft) = &recv.reference.as_ref().unwrap().1 {
286 write!(w, "'{} ", lft.ident).unwrap();
288 if recv.mutability.is_some() {
289 write!(w, "mut self").unwrap();
291 write!(w, "self").unwrap();
294 syn::FnArg::Typed(arg) => {
295 if !arg.attrs.is_empty() { unimplemented!(); }
297 syn::Pat::Ident(ident) => {
298 if !ident.attrs.is_empty() || ident.by_ref.is_some() ||
299 ident.mutability.is_some() || ident.subpat.is_some() {
302 write!(w, ", {}{}: ", if types.skip_arg(&*arg.ty, Some(&gen_types)) { "_" } else { "" }, ident.ident).unwrap();
304 _ => unimplemented!(),
306 types.write_rust_type(w, Some(&gen_types), &*arg.ty);
310 write!(w, ")").unwrap();
311 match &m.sig.output {
312 syn::ReturnType::Type(_, rtype) => {
313 write!(w, " -> ").unwrap();
314 types.write_rust_type(w, Some(&gen_types), &*rtype)
318 write!(w, " {{\n\t\t").unwrap();
319 match export_status(&m.attrs) {
320 ExportStatus::NoExport => {
325 if let syn::ReturnType::Type(_, rtype) = &m.sig.output {
326 if let syn::Type::Reference(r) = &**rtype {
327 assert_eq!(m.sig.inputs.len(), 1); // Must only take self!
328 writeln!(w, "if let Some(f) = self.set_{} {{", m.sig.ident).unwrap();
329 writeln!(w, "\t\t\t(f)(self);").unwrap();
330 write!(w, "\t\t}}\n\t\t").unwrap();
331 types.write_from_c_conversion_to_ref_prefix(w, &*r.elem, Some(&gen_types));
332 write!(w, "self.{}", m.sig.ident).unwrap();
333 types.write_from_c_conversion_to_ref_suffix(w, &*r.elem, Some(&gen_types));
334 writeln!(w, "\n\t}}").unwrap();
339 write_method_var_decl_body(w, &m.sig, "\t", types, Some(&gen_types), true);
340 write!(w, "(self.{})(", m.sig.ident).unwrap();
341 write_method_call_params(w, &m.sig, "\t", types, Some(&gen_types), "", true);
343 writeln!(w, "\n\t}}").unwrap();
346 &syn::TraitItem::Type(ref t) => {
347 if t.default.is_some() || t.generics.lt_token.is_some() { unimplemented!(); }
348 let mut bounds_iter = t.bounds.iter();
349 match bounds_iter.next().unwrap() {
350 syn::TypeParamBound::Trait(tr) => {
351 writeln!(w, "\ttype {} = crate::{};", t.ident, types.resolve_path(&tr.path, Some(&gen_types))).unwrap();
353 _ => unimplemented!(),
355 if bounds_iter.next().is_some() { unimplemented!(); }
357 _ => unimplemented!(),
360 writeln!(w, "}}\n").unwrap();
361 writeln!(w, "// We're essentially a pointer already, or at least a set of pointers, so allow us to be used").unwrap();
362 writeln!(w, "// directly as a Deref trait in higher-level structs:").unwrap();
363 writeln!(w, "impl std::ops::Deref for {} {{\n\ttype Target = Self;", trait_name).unwrap();
364 writeln!(w, "\tfn deref(&self) -> &Self {{\n\t\tself\n\t}}\n}}").unwrap();
366 writeln!(w, "/// Calls the free function if one is set").unwrap();
367 writeln!(w, "#[no_mangle]\npub extern \"C\" fn {}_free(this_ptr: {}) {{ }}", trait_name, trait_name).unwrap();
368 writeln!(w, "impl Drop for {} {{", trait_name).unwrap();
369 writeln!(w, "\tfn drop(&mut self) {{").unwrap();
370 writeln!(w, "\t\tif let Some(f) = self.free {{").unwrap();
371 writeln!(w, "\t\t\tf(self.this_arg);").unwrap();
372 writeln!(w, "\t\t}}\n\t}}\n}}").unwrap();
374 write_cpp_wrapper(cpp_headers, &trait_name, true);
375 types.trait_declared(&t.ident, t);
378 /// Write out a simple "opaque" type (eg structs) which contain a pointer to the native Rust type
379 /// and a flag to indicate whether Drop'ing the mapped struct drops the underlying Rust type.
381 /// Also writes out a _free function and a C++ wrapper which handles calling _free.
382 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) {
383 // If we directly read the original type by its original name, cbindgen hits
384 // https://github.com/eqrion/cbindgen/issues/286 Thus, instead, we import it as a temporary
385 // name and then reference it by that name, which works around the issue.
386 write!(w, "\nuse {}::{}::{} as native{}Import;\ntype native{} = native{}Import", types.orig_crate, types.module_path, ident, ident, ident, ident).unwrap();
387 maybe_write_generics(w, &generics, &types, true);
388 writeln!(w, ";\n").unwrap();
389 writeln!(extra_headers, "struct native{}Opaque;\ntypedef struct native{}Opaque LDKnative{};", ident, ident, ident).unwrap();
390 writeln_docs(w, &attrs, "");
391 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();
392 writeln!(w, "\t/// the Rust equivalent takes an Option, it may be set to null to indicate None.").unwrap();
393 writeln!(w, "\tpub inner: *mut native{},\n\tpub is_owned: bool,\n}}\n", ident).unwrap();
394 writeln!(w, "impl Drop for {} {{\n\tfn drop(&mut self) {{", struct_name).unwrap();
395 writeln!(w, "\t\tif self.is_owned && !self.inner.is_null() {{").unwrap();
396 writeln!(w, "\t\t\tlet _ = unsafe {{ Box::from_raw(self.inner) }};\n\t\t}}\n\t}}\n}}").unwrap();
397 writeln!(w, "#[no_mangle]\npub extern \"C\" fn {}_free(this_ptr: {}) {{ }}", struct_name, struct_name).unwrap();
398 writeln!(w, "#[allow(unused)]").unwrap();
399 writeln!(w, "/// Used only if an object of this type is returned as a trait impl by a method").unwrap();
400 writeln!(w, "extern \"C\" fn {}_free_void(this_ptr: *mut c_void) {{", struct_name).unwrap();
401 writeln!(w, "\tunsafe {{ let _ = Box::from_raw(this_ptr as *mut native{}); }}\n}}", struct_name).unwrap();
402 writeln!(w, "#[allow(unused)]").unwrap();
403 writeln!(w, "/// When moving out of the pointer, we have to ensure we aren't a reference, this makes that easy").unwrap();
404 writeln!(w, "impl {} {{", struct_name).unwrap();
405 writeln!(w, "\tpub(crate) fn take_ptr(mut self) -> *mut native{} {{", struct_name).unwrap();
406 writeln!(w, "\t\tassert!(self.is_owned);").unwrap();
407 writeln!(w, "\t\tlet ret = self.inner;").unwrap();
408 writeln!(w, "\t\tself.inner = std::ptr::null_mut();").unwrap();
409 writeln!(w, "\t\tret").unwrap();
410 writeln!(w, "\t}}\n}}").unwrap();
412 'attr_loop: for attr in attrs.iter() {
413 let tokens_clone = attr.tokens.clone();
414 let mut token_iter = tokens_clone.into_iter();
415 if let Some(token) = token_iter.next() {
417 TokenTree::Group(g) => {
418 if format!("{}", single_ident_generic_path_to_ident(&attr.path).unwrap()) == "derive" {
419 for id in g.stream().into_iter() {
420 if let TokenTree::Ident(i) = id {
422 writeln!(w, "impl Clone for {} {{", struct_name).unwrap();
423 writeln!(w, "\tfn clone(&self) -> Self {{").unwrap();
424 writeln!(w, "\t\tSelf {{").unwrap();
425 writeln!(w, "\t\t\tinner: Box::into_raw(Box::new(unsafe {{ &*self.inner }}.clone())),").unwrap();
426 writeln!(w, "\t\t\tis_owned: true,").unwrap();
427 writeln!(w, "\t\t}}\n\t}}\n}}").unwrap();
428 writeln!(w, "#[allow(unused)]").unwrap();
429 writeln!(w, "/// Used only if an object of this type is returned as a trait impl by a method").unwrap();
430 writeln!(w, "pub(crate) extern \"C\" fn {}_clone_void(this_ptr: *const c_void) -> *mut c_void {{", struct_name).unwrap();
431 writeln!(w, "\tBox::into_raw(Box::new(unsafe {{ (*(this_ptr as *mut native{})).clone() }})) as *mut c_void", struct_name).unwrap();
432 writeln!(w, "}}").unwrap();
433 writeln!(w, "#[no_mangle]").unwrap();
434 writeln!(w, "pub extern \"C\" fn {}_clone(orig: &{}) -> {} {{", struct_name, struct_name, struct_name).unwrap();
435 writeln!(w, "\t{} {{ inner: Box::into_raw(Box::new(unsafe {{ &*orig.inner }}.clone())), is_owned: true }}", struct_name).unwrap();
436 writeln!(w, "}}").unwrap();
448 write_cpp_wrapper(cpp_headers, &format!("{}", ident), true);
451 /// Writes out all the relevant mappings for a Rust struct, deferring to writeln_opaque to generate
452 /// the struct itself, and then writing getters and setters for public, understood-type fields and
453 /// a constructor if every field is public.
454 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) {
455 let struct_name = &format!("{}", s.ident);
456 let export = export_status(&s.attrs);
458 ExportStatus::Export => {},
459 ExportStatus::TestOnly => return,
460 ExportStatus::NoExport => {
461 types.struct_ignored(&s.ident);
466 writeln_opaque(w, &s.ident, struct_name, &s.generics, &s.attrs, types, extra_headers, cpp_headers);
468 eprintln!("exporting fields for {}", struct_name);
469 if let syn::Fields::Named(fields) = &s.fields {
470 let mut gen_types = GenericTypes::new();
471 assert!(gen_types.learn_generics(&s.generics, types));
473 let mut all_fields_settable = true;
474 for field in fields.named.iter() {
475 if let syn::Visibility::Public(_) = field.vis {
476 let export = export_status(&field.attrs);
478 ExportStatus::Export => {},
479 ExportStatus::NoExport|ExportStatus::TestOnly => {
480 all_fields_settable = false;
485 if let Some(ident) = &field.ident {
486 let ref_type = syn::Type::Reference(syn::TypeReference {
487 and_token: syn::Token!(&)(Span::call_site()), lifetime: None, mutability: None,
488 elem: Box::new(field.ty.clone()) });
489 if types.understood_c_type(&ref_type, Some(&gen_types)) {
490 writeln_docs(w, &field.attrs, "");
491 write!(w, "#[no_mangle]\npub extern \"C\" fn {}_get_{}(this_ptr: &{}) -> ", struct_name, ident, struct_name).unwrap();
492 types.write_c_type(w, &ref_type, Some(&gen_types), true);
493 write!(w, " {{\n\tlet mut inner_val = &mut unsafe {{ &mut *this_ptr.inner }}.{};\n\t", ident).unwrap();
494 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);
495 if local_var { write!(w, "\n\t").unwrap(); }
496 types.write_to_c_conversion_inline_prefix(w, &ref_type, Some(&gen_types), true);
498 write!(w, "inner_val").unwrap();
500 write!(w, "(*inner_val)").unwrap();
502 types.write_to_c_conversion_inline_suffix(w, &ref_type, Some(&gen_types), true);
503 writeln!(w, "\n}}").unwrap();
506 if types.understood_c_type(&field.ty, Some(&gen_types)) {
507 writeln_docs(w, &field.attrs, "");
508 write!(w, "#[no_mangle]\npub extern \"C\" fn {}_set_{}(this_ptr: &mut {}, mut val: ", struct_name, ident, struct_name).unwrap();
509 types.write_c_type(w, &field.ty, Some(&gen_types), false);
510 write!(w, ") {{\n\t").unwrap();
511 let local_var = types.write_from_c_conversion_new_var(w, &syn::Ident::new("val", Span::call_site()), &field.ty, Some(&gen_types));
512 if local_var { write!(w, "\n\t").unwrap(); }
513 write!(w, "unsafe {{ &mut *this_ptr.inner }}.{} = ", ident).unwrap();
514 types.write_from_c_conversion_prefix(w, &field.ty, Some(&gen_types));
515 write!(w, "val").unwrap();
516 types.write_from_c_conversion_suffix(w, &field.ty, Some(&gen_types));
517 writeln!(w, ";\n}}").unwrap();
518 } else { all_fields_settable = false; }
519 } else { all_fields_settable = false; }
520 } else { all_fields_settable = false; }
523 if all_fields_settable {
524 // Build a constructor!
525 write!(w, "#[must_use]\n#[no_mangle]\npub extern \"C\" fn {}_new(", struct_name).unwrap();
526 for (idx, field) in fields.named.iter().enumerate() {
527 if idx != 0 { write!(w, ", ").unwrap(); }
528 write!(w, "mut {}_arg: ", field.ident.as_ref().unwrap()).unwrap();
529 types.write_c_type(w, &field.ty, Some(&gen_types), false);
531 write!(w, ") -> {} {{\n\t", struct_name).unwrap();
532 for field in fields.named.iter() {
533 let field_name = format!("{}_arg", field.ident.as_ref().unwrap());
534 if types.write_from_c_conversion_new_var(w, &syn::Ident::new(&field_name, Span::call_site()), &field.ty, Some(&gen_types)) {
535 write!(w, "\n\t").unwrap();
538 writeln!(w, "{} {{ inner: Box::into_raw(Box::new(native{} {{", struct_name, s.ident).unwrap();
539 for field in fields.named.iter() {
540 write!(w, "\t\t{}: ", field.ident.as_ref().unwrap()).unwrap();
541 types.write_from_c_conversion_prefix(w, &field.ty, Some(&gen_types));
542 write!(w, "{}_arg", field.ident.as_ref().unwrap()).unwrap();
543 types.write_from_c_conversion_suffix(w, &field.ty, Some(&gen_types));
544 writeln!(w, ",").unwrap();
546 writeln!(w, "\t}})), is_owned: true }}\n}}").unwrap();
550 types.struct_imported(&s.ident, struct_name.clone());
553 /// Prints a relevant conversion for impl *
555 /// For simple impl Struct {}s, this just outputs the wrapper functions as Struct_fn_name() { .. }.
557 /// For impl Trait for Struct{}s, this non-exported generates wrapper functions as
558 /// Trait_Struct_fn_name and a Struct_as_Trait(&struct) -> Trait function which returns a populated
559 /// Trait struct containing a pointer to the passed struct's inner field and the wrapper functions.
561 /// A few non-crate Traits are hard-coded including Default.
562 fn writeln_impl<W: std::io::Write>(w: &mut W, i: &syn::ItemImpl, types: &mut TypeResolver) {
563 if let &syn::Type::Path(ref p) = &*i.self_ty {
564 if p.qself.is_some() { unimplemented!(); }
565 if let Some(ident) = single_ident_generic_path_to_ident(&p.path) {
566 if let Some(resolved_path) = types.maybe_resolve_non_ignored_ident(&ident) {
567 let mut gen_types = GenericTypes::new();
568 if !gen_types.learn_generics(&i.generics, types) {
569 eprintln!("Not implementing anything for impl {} due to not understood generics", ident);
573 if i.defaultness.is_some() || i.unsafety.is_some() { unimplemented!(); }
574 if let Some(trait_path) = i.trait_.as_ref() {
575 if trait_path.0.is_some() { unimplemented!(); }
576 if types.understood_c_path(&trait_path.1) {
577 let full_trait_path = types.resolve_path(&trait_path.1, None);
578 let trait_obj = *types.crate_types.traits.get(&full_trait_path).unwrap();
579 // We learn the associated types maping from the original trait object.
580 // That's great, except that they are unresolved idents, so if we learn
581 // mappings from a trai defined in a different file, we may mis-resolve or
582 // fail to resolve the mapped types.
583 gen_types.learn_associated_types(trait_obj, types);
584 let mut impl_associated_types = HashMap::new();
585 for item in i.items.iter() {
587 syn::ImplItem::Type(t) => {
588 if let syn::Type::Path(p) = &t.ty {
589 if let Some(id) = single_ident_generic_path_to_ident(&p.path) {
590 impl_associated_types.insert(&t.ident, id);
598 let export = export_status(&trait_obj.attrs);
600 ExportStatus::Export => {},
601 ExportStatus::NoExport|ExportStatus::TestOnly => return,
604 // For cases where we have a concrete native object which implements a
605 // trait and need to return the C-mapped version of the trait, provide a
606 // From<> implementation which does all the work to ensure free is handled
607 // properly. This way we can call this method from deep in the
608 // type-conversion logic without actually knowing the concrete native type.
609 writeln!(w, "impl From<native{}> for crate::{} {{", ident, full_trait_path).unwrap();
610 writeln!(w, "\tfn from(obj: native{}) -> Self {{", ident).unwrap();
611 writeln!(w, "\t\tlet mut rust_obj = {} {{ inner: Box::into_raw(Box::new(obj)), is_owned: true }};", ident).unwrap();
612 writeln!(w, "\t\tlet mut ret = {}_as_{}(&rust_obj);", ident, trait_obj.ident).unwrap();
613 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();
614 writeln!(w, "\t\trust_obj.inner = std::ptr::null_mut();").unwrap();
615 writeln!(w, "\t\tret.free = Some({}_free_void);", ident).unwrap();
616 writeln!(w, "\t\tret\n\t}}\n}}").unwrap();
618 write!(w, "#[no_mangle]\npub extern \"C\" fn {}_as_{}(this_arg: *const {}) -> crate::{} {{\n", ident, trait_obj.ident, ident, full_trait_path).unwrap();
619 writeln!(w, "\tcrate::{} {{", full_trait_path).unwrap();
620 writeln!(w, "\t\tthis_arg: unsafe {{ (*this_arg).inner as *mut c_void }},").unwrap();
621 writeln!(w, "\t\tfree: None,").unwrap();
623 macro_rules! write_meth {
624 ($m: expr, $trait: expr, $indent: expr) => {
625 let trait_method = $trait.items.iter().filter_map(|item| {
626 if let syn::TraitItem::Method(t_m) = item { Some(t_m) } else { None }
627 }).find(|trait_meth| trait_meth.sig.ident == $m.sig.ident).unwrap();
628 match export_status(&trait_method.attrs) {
629 ExportStatus::Export => {},
630 ExportStatus::NoExport => {
631 write!(w, "{}\t\t//XXX: Need to export {}\n", $indent, $m.sig.ident).unwrap();
634 ExportStatus::TestOnly => continue,
637 let mut printed = false;
638 if let syn::ReturnType::Type(_, rtype) = &$m.sig.output {
639 if let syn::Type::Reference(r) = &**rtype {
640 write!(w, "\n\t\t{}{}: ", $indent, $m.sig.ident).unwrap();
641 types.write_empty_rust_val(Some(&gen_types), w, &*r.elem);
642 writeln!(w, ",\n{}\t\tset_{}: Some({}_{}_set_{}),", $indent, $m.sig.ident, ident, trait_obj.ident, $m.sig.ident).unwrap();
647 write!(w, "{}\t\t{}: {}_{}_{},\n", $indent, $m.sig.ident, ident, trait_obj.ident, $m.sig.ident).unwrap();
651 for item in trait_obj.items.iter() {
653 syn::TraitItem::Method(m) => {
654 write_meth!(m, trait_obj, "");
659 walk_supertraits!(trait_obj, types, (
661 writeln!(w, "\t\tclone: Some({}_clone_void),", ident).unwrap();
664 if s.starts_with("util::") {
665 let supertrait_obj = types.crate_types.traits.get(s).unwrap();
666 writeln!(w, "\t\t{}: crate::{} {{", t, s).unwrap();
667 writeln!(w, "\t\t\tthis_arg: unsafe {{ (*this_arg).inner as *mut c_void }},").unwrap();
668 writeln!(w, "\t\t\tfree: None,").unwrap();
669 for item in supertrait_obj.items.iter() {
671 syn::TraitItem::Method(m) => {
672 write_meth!(m, supertrait_obj, "\t");
677 write!(w, "\t\t}},\n").unwrap();
681 write!(w, "\t}}\n}}\nuse {}::{} as {}TraitImport;\n", types.orig_crate, full_trait_path, trait_obj.ident).unwrap();
683 macro_rules! impl_meth {
684 ($m: expr, $trait: expr, $indent: expr) => {
685 let trait_method = $trait.items.iter().filter_map(|item| {
686 if let syn::TraitItem::Method(t_m) = item { Some(t_m) } else { None }
687 }).find(|trait_meth| trait_meth.sig.ident == $m.sig.ident).unwrap();
688 match export_status(&trait_method.attrs) {
689 ExportStatus::Export => {},
690 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
693 if let syn::ReturnType::Type(_, _) = &$m.sig.output {
694 writeln!(w, "#[must_use]").unwrap();
696 write!(w, "extern \"C\" fn {}_{}_{}(", ident, trait_obj.ident, $m.sig.ident).unwrap();
697 gen_types.push_ctx();
698 assert!(gen_types.learn_generics(&$m.sig.generics, types));
699 write_method_params(w, &$m.sig, "c_void", types, Some(&gen_types), true, true);
700 write!(w, " {{\n\t").unwrap();
701 write_method_var_decl_body(w, &$m.sig, "", types, Some(&gen_types), false);
702 let mut takes_self = false;
703 for inp in $m.sig.inputs.iter() {
704 if let syn::FnArg::Receiver(_) = inp {
709 write!(w, "unsafe {{ &mut *(this_arg as *mut native{}) }}.{}(", ident, $m.sig.ident).unwrap();
711 write!(w, "{}::{}::{}(", types.orig_crate, resolved_path, $m.sig.ident).unwrap();
714 let mut real_type = "".to_string();
715 match &$m.sig.output {
716 syn::ReturnType::Type(_, rtype) => {
717 if let Some(mut remaining_path) = first_seg_self(&*rtype) {
718 if let Some(associated_seg) = get_single_remaining_path_seg(&mut remaining_path) {
719 real_type = format!("{}", impl_associated_types.get(associated_seg).unwrap());
725 write_method_call_params(w, &$m.sig, "", types, Some(&gen_types), &real_type, false);
727 write!(w, "\n}}\n").unwrap();
728 if let syn::ReturnType::Type(_, rtype) = &$m.sig.output {
729 if let syn::Type::Reference(r) = &**rtype {
730 assert_eq!($m.sig.inputs.len(), 1); // Must only take self
731 writeln!(w, "extern \"C\" fn {}_{}_set_{}(trait_self_arg: &{}) {{", ident, trait_obj.ident, $m.sig.ident, trait_obj.ident).unwrap();
732 writeln!(w, "\t// This is a bit race-y in the general case, but for our specific use-cases today, we're safe").unwrap();
733 writeln!(w, "\t// Specifically, we must ensure that the first time we're called it can never be in parallel").unwrap();
734 write!(w, "\tif ").unwrap();
735 types.write_empty_rust_val_check(Some(&gen_types), w, &*r.elem, &format!("trait_self_arg.{}", $m.sig.ident));
736 writeln!(w, " {{").unwrap();
737 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();
738 writeln!(w, "\t}}").unwrap();
739 writeln!(w, "}}").unwrap();
745 for item in i.items.iter() {
747 syn::ImplItem::Method(m) => {
748 impl_meth!(m, trait_obj, "");
750 syn::ImplItem::Type(_) => {},
751 _ => unimplemented!(),
754 walk_supertraits!(trait_obj, types, (
756 if s.starts_with("util::") {
757 writeln!(w, "use {}::{} as native{}Trait;", types.orig_crate, s, t).unwrap();
758 let supertrait_obj = *types.crate_types.traits.get(s).unwrap();
759 for item in supertrait_obj.items.iter() {
761 syn::TraitItem::Method(m) => {
762 impl_meth!(m, supertrait_obj, "\t");
770 write!(w, "\n").unwrap();
771 } else if let Some(trait_ident) = trait_path.1.get_ident() {
772 //XXX: implement for other things like ToString
773 match &format!("{}", trait_ident) as &str {
776 write!(w, "#[must_use]\n#[no_mangle]\npub extern \"C\" fn {}_default() -> {} {{\n", ident, ident).unwrap();
777 write!(w, "\t{} {{ inner: Box::into_raw(Box::new(Default::default())), is_owned: true }}\n", ident).unwrap();
778 write!(w, "}}\n").unwrap();
781 // If we have no generics, try a manual implementation:
782 _ if p.path.get_ident().is_some() => maybe_convert_trait_impl(w, &trait_path.1, &ident, types),
785 } else if p.path.get_ident().is_some() {
786 // If we have no generics, try a manual implementation:
787 maybe_convert_trait_impl(w, &trait_path.1, &ident, types);
790 let declared_type = (*types.get_declared_type(&ident).unwrap()).clone();
791 for item in i.items.iter() {
793 syn::ImplItem::Method(m) => {
794 if let syn::Visibility::Public(_) = m.vis {
795 match export_status(&m.attrs) {
796 ExportStatus::Export => {},
797 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
799 if m.defaultness.is_some() { unimplemented!(); }
800 writeln_docs(w, &m.attrs, "");
801 if let syn::ReturnType::Type(_, _) = &m.sig.output {
802 writeln!(w, "#[must_use]").unwrap();
804 write!(w, "#[no_mangle]\npub extern \"C\" fn {}_{}(", ident, m.sig.ident).unwrap();
805 let ret_type = match &declared_type {
806 DeclType::MirroredEnum => format!("{}", ident),
807 DeclType::StructImported => format!("{}", ident),
808 _ => unimplemented!(),
810 gen_types.push_ctx();
811 assert!(gen_types.learn_generics(&m.sig.generics, types));
812 write_method_params(w, &m.sig, &ret_type, types, Some(&gen_types), false, true);
813 write!(w, " {{\n\t").unwrap();
814 write_method_var_decl_body(w, &m.sig, "", types, Some(&gen_types), false);
815 let mut takes_self = false;
816 let mut takes_mut_self = false;
817 for inp in m.sig.inputs.iter() {
818 if let syn::FnArg::Receiver(r) = inp {
820 if r.mutability.is_some() { takes_mut_self = true; }
824 write!(w, "unsafe {{ &mut (*(this_arg.inner as *mut native{})) }}.{}(", ident, m.sig.ident).unwrap();
825 } else if takes_self {
826 write!(w, "unsafe {{ &*this_arg.inner }}.{}(", m.sig.ident).unwrap();
828 write!(w, "{}::{}::{}(", types.orig_crate, resolved_path, m.sig.ident).unwrap();
830 write_method_call_params(w, &m.sig, "", types, Some(&gen_types), &ret_type, false);
832 writeln!(w, "\n}}\n").unwrap();
840 eprintln!("Not implementing anything for {} due to no-resolve (probably the type isn't pub or its marked not exported)", ident);
846 /// Returns true if the enum will be mapped as an opaue (ie struct with a pointer to the underlying
847 /// type), otherwise it is mapped into a transparent, C-compatible version of itself.
848 fn is_enum_opaque(e: &syn::ItemEnum) -> bool {
849 for var in e.variants.iter() {
850 if let syn::Fields::Unit = var.fields {
851 } else if let syn::Fields::Named(fields) = &var.fields {
852 for field in fields.named.iter() {
853 match export_status(&field.attrs) {
854 ExportStatus::Export|ExportStatus::TestOnly => {},
855 ExportStatus::NoExport => return true,
865 /// Print a mapping of an enum. If all of the enum's fields are C-mapped in some form (or the enum
866 /// is unitary), we generate an equivalent enum with all types replaced with their C mapped
867 /// versions followed by conversion functions which map between the Rust version and the C mapped
869 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) {
870 match export_status(&e.attrs) {
871 ExportStatus::Export => {},
872 ExportStatus::NoExport|ExportStatus::TestOnly => return,
875 if is_enum_opaque(e) {
876 eprintln!("Skipping enum {} as it contains non-unit fields", e.ident);
877 writeln_opaque(w, &e.ident, &format!("{}", e.ident), &e.generics, &e.attrs, types, extra_headers, cpp_headers);
878 types.enum_ignored(&e.ident);
881 writeln_docs(w, &e.attrs, "");
883 if e.generics.lt_token.is_some() {
886 types.mirrored_enum_declared(&e.ident);
888 let mut needs_free = false;
890 writeln!(w, "#[must_use]\n#[derive(Clone)]\n#[repr(C)]\npub enum {} {{", e.ident).unwrap();
891 for var in e.variants.iter() {
892 assert_eq!(export_status(&var.attrs), ExportStatus::Export); // We can't partially-export a mirrored enum
893 writeln_docs(w, &var.attrs, "\t");
894 write!(w, "\t{}", var.ident).unwrap();
895 if let syn::Fields::Named(fields) = &var.fields {
897 writeln!(w, " {{").unwrap();
898 for field in fields.named.iter() {
899 if export_status(&field.attrs) == ExportStatus::TestOnly { continue; }
900 write!(w, "\t\t{}: ", field.ident.as_ref().unwrap()).unwrap();
901 types.write_c_type(w, &field.ty, None, false);
902 writeln!(w, ",").unwrap();
904 write!(w, "\t}}").unwrap();
906 if var.discriminant.is_some() { unimplemented!(); }
907 writeln!(w, ",").unwrap();
909 writeln!(w, "}}\nuse {}::{}::{} as native{};\nimpl {} {{", types.orig_crate, types.module_path, e.ident, e.ident, e.ident).unwrap();
911 macro_rules! write_conv {
912 ($fn_sig: expr, $to_c: expr, $ref: expr) => {
913 writeln!(w, "\t#[allow(unused)]\n\tpub(crate) fn {} {{\n\t\tmatch {} {{", $fn_sig, if $to_c { "native" } else { "self" }).unwrap();
914 for var in e.variants.iter() {
915 write!(w, "\t\t\t{}{}::{} ", if $to_c { "native" } else { "" }, e.ident, var.ident).unwrap();
916 if let syn::Fields::Named(fields) = &var.fields {
917 write!(w, "{{").unwrap();
918 for field in fields.named.iter() {
919 if export_status(&field.attrs) == ExportStatus::TestOnly { continue; }
920 write!(w, "{}{}, ", if $ref { "ref " } else { "mut " }, field.ident.as_ref().unwrap()).unwrap();
922 write!(w, "}} ").unwrap();
924 write!(w, "=>").unwrap();
925 if let syn::Fields::Named(fields) = &var.fields {
926 write!(w, " {{\n\t\t\t\t").unwrap();
927 for field in fields.named.iter() {
928 if export_status(&field.attrs) == ExportStatus::TestOnly { continue; }
929 let mut sink = ::std::io::sink();
930 let mut out: &mut dyn std::io::Write = if $ref { &mut sink } else { w };
931 let new_var = if $to_c {
932 types.write_to_c_conversion_new_var(&mut out, field.ident.as_ref().unwrap(), &field.ty, None, false)
934 types.write_from_c_conversion_new_var(&mut out, field.ident.as_ref().unwrap(), &field.ty, None)
938 write!(w, "let mut {}_nonref = (*{}).clone();\n\t\t\t\t", field.ident.as_ref().unwrap(), field.ident.as_ref().unwrap()).unwrap();
940 let nonref_ident = syn::Ident::new(&format!("{}_nonref", field.ident.as_ref().unwrap()), Span::call_site());
942 types.write_to_c_conversion_new_var(w, &nonref_ident, &field.ty, None, false);
944 types.write_from_c_conversion_new_var(w, &nonref_ident, &field.ty, None);
946 write!(w, "\n\t\t\t\t").unwrap();
949 write!(w, "\n\t\t\t\t").unwrap();
953 } else { write!(w, " ").unwrap(); }
954 write!(w, "{}{}::{}", if $to_c { "" } else { "native" }, e.ident, var.ident).unwrap();
955 if let syn::Fields::Named(fields) = &var.fields {
956 write!(w, " {{").unwrap();
957 for field in fields.named.iter() {
958 if export_status(&field.attrs) == ExportStatus::TestOnly { continue; }
959 write!(w, "\n\t\t\t\t\t{}: ", field.ident.as_ref().unwrap()).unwrap();
961 types.write_to_c_conversion_inline_prefix(w, &field.ty, None, false);
963 types.write_from_c_conversion_prefix(w, &field.ty, None);
966 field.ident.as_ref().unwrap(),
967 if $ref { "_nonref" } else { "" }).unwrap();
969 types.write_to_c_conversion_inline_suffix(w, &field.ty, None, false);
971 types.write_from_c_conversion_suffix(w, &field.ty, None);
973 write!(w, ",").unwrap();
975 writeln!(w, "\n\t\t\t\t}}").unwrap();
976 write!(w, "\t\t\t}}").unwrap();
978 writeln!(w, ",").unwrap();
980 writeln!(w, "\t\t}}\n\t}}").unwrap();
984 write_conv!(format!("to_native(&self) -> native{}", e.ident), false, true);
985 write_conv!(format!("into_native(self) -> native{}", e.ident), false, false);
986 write_conv!(format!("from_native(native: &native{}) -> Self", e.ident), true, true);
987 write_conv!(format!("native_into(native: native{}) -> Self", e.ident), true, false);
988 writeln!(w, "}}").unwrap();
991 writeln!(w, "#[no_mangle]\npub extern \"C\" fn {}_free(this_ptr: {}) {{ }}", e.ident, e.ident).unwrap();
993 writeln!(w, "#[no_mangle]").unwrap();
994 writeln!(w, "pub extern \"C\" fn {}_clone(orig: &{}) -> {} {{", e.ident, e.ident, e.ident).unwrap();
995 writeln!(w, "\torig.clone()").unwrap();
996 writeln!(w, "}}").unwrap();
997 write_cpp_wrapper(cpp_headers, &format!("{}", e.ident), needs_free);
1000 fn writeln_fn<'a, 'b, W: std::io::Write>(w: &mut W, f: &'a syn::ItemFn, types: &mut TypeResolver<'b, 'a>) {
1001 match export_status(&f.attrs) {
1002 ExportStatus::Export => {},
1003 ExportStatus::NoExport|ExportStatus::TestOnly => return,
1005 writeln_docs(w, &f.attrs, "");
1007 let mut gen_types = GenericTypes::new();
1008 if !gen_types.learn_generics(&f.sig.generics, types) { return; }
1010 write!(w, "#[no_mangle]\npub extern \"C\" fn {}(", f.sig.ident).unwrap();
1011 write_method_params(w, &f.sig, "", types, Some(&gen_types), false, true);
1012 write!(w, " {{\n\t").unwrap();
1013 write_method_var_decl_body(w, &f.sig, "", types, Some(&gen_types), false);
1014 write!(w, "{}::{}::{}(", types.orig_crate, types.module_path, f.sig.ident).unwrap();
1015 write_method_call_params(w, &f.sig, "", types, Some(&gen_types), "", false);
1016 writeln!(w, "\n}}\n").unwrap();
1019 // ********************************
1020 // *** File/Crate Walking Logic ***
1021 // ********************************
1023 /// Simple utility to walk the modules in a crate - iterating over the modules (with file paths) in
1025 struct FileIter<'a, I: Iterator<Item = &'a syn::Item>> {
1031 impl<'a, I: Iterator<Item = &'a syn::Item>> Iterator for FileIter<'a, I> {
1032 type Item = (String, String, &'a syn::ItemMod);
1033 fn next(&mut self) -> std::option::Option<<Self as std::iter::Iterator>::Item> {
1035 match self.item_iter.next() {
1036 Some(syn::Item::Mod(m)) => {
1037 if let syn::Visibility::Public(_) = m.vis {
1038 match export_status(&m.attrs) {
1039 ExportStatus::Export => {},
1040 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1043 let f_path = format!("{}/{}.rs", (self.path.as_ref() as &Path).parent().unwrap().display(), m.ident);
1044 let new_mod = if self.module.is_empty() { format!("{}", m.ident) } else { format!("{}::{}", self.module, m.ident) };
1045 if let Ok(_) = File::open(&format!("{}/{}", self.in_dir, f_path)) {
1046 return Some((f_path, new_mod, m));
1049 format!("{}/{}/mod.rs", (self.path.as_ref() as &Path).parent().unwrap().display(), m.ident),
1055 None => return None,
1060 fn file_iter<'a>(file: &'a syn::File, in_dir: &'a str, path: &'a str, module: &'a str) ->
1061 impl Iterator<Item = (String, String, &'a syn::ItemMod)> + 'a {
1062 FileIter { in_dir, path, module, item_iter: file.items.iter() }
1065 /// A struct containing the syn::File AST for each file in the crate.
1066 struct FullLibraryAST {
1067 files: HashMap<String, syn::File>,
1070 /// Do the Real Work of mapping an original file to C-callable wrappers. Creates a new file at
1071 /// `out_path` and fills it with wrapper structs/functions to allow calling the things in the AST
1072 /// at `module` from C.
1073 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) {
1074 let syntax = if let Some(ast) = libast.files.get(module) { ast } else { return };
1076 assert!(syntax.shebang.is_none()); // Not sure what this is, hope we dont have one
1078 let new_file_path = format!("{}/{}", out_dir, path);
1079 let _ = std::fs::create_dir((&new_file_path.as_ref() as &std::path::Path).parent().unwrap());
1080 let mut out = std::fs::OpenOptions::new().write(true).create(true).truncate(true)
1081 .open(new_file_path).expect("Unable to open new src file");
1083 assert_eq!(export_status(&syntax.attrs), ExportStatus::Export);
1084 writeln_docs(&mut out, &syntax.attrs, "");
1086 if path.ends_with("/lib.rs") {
1087 // Special-case the top-level lib.rs with various lint allows and a pointer to the c_types
1088 // and bitcoin hand-written modules.
1089 writeln!(out, "#![allow(unknown_lints)]").unwrap();
1090 writeln!(out, "#![allow(non_camel_case_types)]").unwrap();
1091 writeln!(out, "#![allow(non_snake_case)]").unwrap();
1092 writeln!(out, "#![allow(unused_imports)]").unwrap();
1093 writeln!(out, "#![allow(unused_variables)]").unwrap();
1094 writeln!(out, "#![allow(unused_mut)]").unwrap();
1095 writeln!(out, "#![allow(unused_parens)]").unwrap();
1096 writeln!(out, "#![allow(unused_unsafe)]").unwrap();
1097 writeln!(out, "#![allow(unused_braces)]").unwrap();
1098 writeln!(out, "mod c_types;").unwrap();
1099 writeln!(out, "mod bitcoin;").unwrap();
1101 writeln!(out, "\nuse std::ffi::c_void;\nuse bitcoin::hashes::Hash;\nuse crate::c_types::*;\n").unwrap();
1104 for (path, new_mod, m) in file_iter(&syntax, in_dir, path, &module) {
1105 writeln_docs(&mut out, &m.attrs, "");
1106 writeln!(out, "pub mod {};", m.ident).unwrap();
1107 convert_file(libast, crate_types, in_dir, out_dir, &path,
1108 orig_crate, &new_mod, header_file, cpp_header_file);
1111 eprintln!("Converting {} entries...", path);
1113 let mut type_resolver = TypeResolver::new(orig_crate, module, crate_types);
1115 for item in syntax.items.iter() {
1117 syn::Item::Use(u) => type_resolver.process_use(&mut out, &u),
1118 syn::Item::Static(_) => {},
1119 syn::Item::Enum(e) => {
1120 if let syn::Visibility::Public(_) = e.vis {
1121 writeln_enum(&mut out, &e, &mut type_resolver, header_file, cpp_header_file);
1124 syn::Item::Impl(i) => {
1125 writeln_impl(&mut out, &i, &mut type_resolver);
1127 syn::Item::Struct(s) => {
1128 if let syn::Visibility::Public(_) = s.vis {
1129 writeln_struct(&mut out, &s, &mut type_resolver, header_file, cpp_header_file);
1132 syn::Item::Trait(t) => {
1133 if let syn::Visibility::Public(_) = t.vis {
1134 writeln_trait(&mut out, &t, &mut type_resolver, header_file, cpp_header_file);
1137 syn::Item::Mod(_) => {}, // We don't have to do anything - the top loop handles these.
1138 syn::Item::Const(c) => {
1139 // Re-export any primitive-type constants.
1140 if let syn::Visibility::Public(_) = c.vis {
1141 if let syn::Type::Path(p) = &*c.ty {
1142 let resolved_path = type_resolver.resolve_path(&p.path, None);
1143 if type_resolver.is_primitive(&resolved_path) {
1144 writeln!(out, "\n#[no_mangle]").unwrap();
1145 writeln!(out, "pub static {}: {} = {}::{}::{};", c.ident, resolved_path, orig_crate, module, c.ident).unwrap();
1150 syn::Item::Type(t) => {
1151 if let syn::Visibility::Public(_) = t.vis {
1152 match export_status(&t.attrs) {
1153 ExportStatus::Export => {},
1154 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1157 let mut process_alias = true;
1158 for tok in t.generics.params.iter() {
1159 if let syn::GenericParam::Lifetime(_) = tok {}
1160 else { process_alias = false; }
1164 syn::Type::Path(_) =>
1165 writeln_opaque(&mut out, &t.ident, &format!("{}", t.ident), &t.generics, &t.attrs, &type_resolver, header_file, cpp_header_file),
1171 syn::Item::Fn(f) => {
1172 if let syn::Visibility::Public(_) = f.vis {
1173 writeln_fn(&mut out, &f, &mut type_resolver);
1176 syn::Item::Macro(m) => {
1177 if m.ident.is_none() { // If its not a macro definition
1178 convert_macro(&mut out, &m.mac.path, &m.mac.tokens, &type_resolver);
1181 syn::Item::Verbatim(_) => {},
1182 syn::Item::ExternCrate(_) => {},
1183 _ => unimplemented!(),
1187 out.flush().unwrap();
1190 /// Load the AST for each file in the crate, filling the FullLibraryAST object
1191 fn load_ast(in_dir: &str, path: &str, module: String, ast_storage: &mut FullLibraryAST) {
1192 eprintln!("Loading {}{}...", in_dir, path);
1194 let mut file = File::open(format!("{}/{}", in_dir, path)).expect("Unable to open file");
1195 let mut src = String::new();
1196 file.read_to_string(&mut src).expect("Unable to read file");
1197 let syntax = syn::parse_file(&src).expect("Unable to parse file");
1199 assert_eq!(export_status(&syntax.attrs), ExportStatus::Export);
1201 for (path, new_mod, _) in file_iter(&syntax, in_dir, path, &module) {
1202 load_ast(in_dir, &path, new_mod, ast_storage);
1204 ast_storage.files.insert(module, syntax);
1207 /// Insert ident -> absolute Path resolutions into imports from the given UseTree and path-prefix.
1208 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>) {
1210 syn::UseTree::Path(p) => {
1211 path.push(syn::PathSegment { ident: p.ident.clone(), arguments: syn::PathArguments::None });
1212 process_use_intern(&p.tree, path, imports);
1214 syn::UseTree::Name(n) => {
1215 path.push(syn::PathSegment { ident: n.ident.clone(), arguments: syn::PathArguments::None });
1216 imports.insert(&n.ident, syn::Path { leading_colon: Some(syn::Token![::](Span::call_site())), segments: path });
1218 syn::UseTree::Group(g) => {
1219 for i in g.items.iter() {
1220 process_use_intern(i, path.clone(), imports);
1227 /// Map all the Paths in a Type into absolute paths given a set of imports (generated via process_use_intern)
1228 fn resolve_imported_refs(imports: &HashMap<&syn::Ident, syn::Path>, mut ty: syn::Type) -> syn::Type {
1230 syn::Type::Path(p) => {
1231 if let Some(ident) = p.path.get_ident() {
1232 if let Some(newpath) = imports.get(ident) {
1233 p.path = newpath.clone();
1235 } else { unimplemented!(); }
1237 syn::Type::Reference(r) => {
1238 r.elem = Box::new(resolve_imported_refs(imports, (*r.elem).clone()));
1240 syn::Type::Slice(s) => {
1241 s.elem = Box::new(resolve_imported_refs(imports, (*s.elem).clone()));
1243 syn::Type::Tuple(t) => {
1244 for e in t.elems.iter_mut() {
1245 *e = resolve_imported_refs(imports, e.clone());
1248 _ => unimplemented!(),
1253 /// Walk the FullLibraryAST, deciding how things will be mapped and adding tracking to CrateTypes.
1254 fn walk_ast<'a>(in_dir: &str, path: &str, module: String, ast_storage: &'a FullLibraryAST, crate_types: &mut CrateTypes<'a>) {
1255 let syntax = if let Some(ast) = ast_storage.files.get(&module) { ast } else { return };
1256 assert_eq!(export_status(&syntax.attrs), ExportStatus::Export);
1258 for (path, new_mod, _) in file_iter(&syntax, in_dir, path, &module) {
1259 walk_ast(in_dir, &path, new_mod, ast_storage, crate_types);
1262 let mut import_maps = HashMap::new();
1264 for item in syntax.items.iter() {
1266 syn::Item::Use(u) => {
1267 process_use_intern(&u.tree, syn::punctuated::Punctuated::new(), &mut import_maps);
1269 syn::Item::Struct(s) => {
1270 if let syn::Visibility::Public(_) = s.vis {
1271 match export_status(&s.attrs) {
1272 ExportStatus::Export => {},
1273 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1275 let struct_path = format!("{}::{}", module, s.ident);
1276 crate_types.opaques.insert(struct_path, &s.ident);
1279 syn::Item::Trait(t) => {
1280 if let syn::Visibility::Public(_) = t.vis {
1281 match export_status(&t.attrs) {
1282 ExportStatus::Export => {},
1283 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1285 let trait_path = format!("{}::{}", module, t.ident);
1286 crate_types.traits.insert(trait_path, &t);
1289 syn::Item::Type(t) => {
1290 if let syn::Visibility::Public(_) = t.vis {
1291 match export_status(&t.attrs) {
1292 ExportStatus::Export => {},
1293 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1295 let type_path = format!("{}::{}", module, t.ident);
1296 let mut process_alias = true;
1297 for tok in t.generics.params.iter() {
1298 if let syn::GenericParam::Lifetime(_) = tok {}
1299 else { process_alias = false; }
1303 syn::Type::Path(_) => {
1304 // If its a path with no generics, assume we don't map the aliased type and map it opaque
1305 crate_types.opaques.insert(type_path, &t.ident);
1308 crate_types.type_aliases.insert(type_path, resolve_imported_refs(&import_maps, (*t.ty).clone()));
1314 syn::Item::Enum(e) if is_enum_opaque(e) => {
1315 if let syn::Visibility::Public(_) = e.vis {
1316 match export_status(&e.attrs) {
1317 ExportStatus::Export => {},
1318 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1320 let enum_path = format!("{}::{}", module, e.ident);
1321 crate_types.opaques.insert(enum_path, &e.ident);
1324 syn::Item::Enum(e) => {
1325 if let syn::Visibility::Public(_) = e.vis {
1326 match export_status(&e.attrs) {
1327 ExportStatus::Export => {},
1328 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1330 let enum_path = format!("{}::{}", module, e.ident);
1331 crate_types.mirrored_enums.insert(enum_path, &e);
1340 let args: Vec<String> = env::args().collect();
1341 if args.len() != 7 {
1342 eprintln!("Usage: source/dir target/dir source_crate_name derived_templates.rs extra/includes.h extra/cpp/includes.hpp");
1346 let mut derived_templates = std::fs::OpenOptions::new().write(true).create(true).truncate(true)
1347 .open(&args[4]).expect("Unable to open new header file");
1348 let mut header_file = std::fs::OpenOptions::new().write(true).create(true).truncate(true)
1349 .open(&args[5]).expect("Unable to open new header file");
1350 let mut cpp_header_file = std::fs::OpenOptions::new().write(true).create(true).truncate(true)
1351 .open(&args[6]).expect("Unable to open new header file");
1353 writeln!(header_file, "#if defined(__GNUC__)\n#define MUST_USE_STRUCT __attribute__((warn_unused))").unwrap();
1354 writeln!(header_file, "#else\n#define MUST_USE_STRUCT\n#endif").unwrap();
1355 writeln!(header_file, "#if defined(__GNUC__)\n#define MUST_USE_RES __attribute__((warn_unused_result))").unwrap();
1356 writeln!(header_file, "#else\n#define MUST_USE_RES\n#endif").unwrap();
1357 writeln!(cpp_header_file, "#include <string.h>\nnamespace LDK {{").unwrap();
1359 // First parse the full crate's ASTs, caching them so that we can hold references to the AST
1360 // objects in other datastructures:
1361 let mut libast = FullLibraryAST { files: HashMap::new() };
1362 load_ast(&args[1], "/lib.rs", "".to_string(), &mut libast);
1364 // ...then walk the ASTs tracking what types we will map, and how, so that we can resolve them
1365 // when parsing other file ASTs...
1366 let mut libtypes = CrateTypes { traits: HashMap::new(), opaques: HashMap::new(), mirrored_enums: HashMap::new(),
1367 type_aliases: HashMap::new(), templates_defined: HashMap::default(), template_file: &mut derived_templates };
1368 walk_ast(&args[1], "/lib.rs", "".to_string(), &libast, &mut libtypes);
1370 // ... finally, do the actual file conversion/mapping, writing out types as we go.
1371 convert_file(&libast, &mut libtypes, &args[1], &args[2], "/lib.rs", &args[3], "", &mut header_file, &mut cpp_header_file);
1373 // For container templates which we created while walking the crate, make sure we add C++
1374 // mapped types so that C++ users can utilize the auto-destructors available.
1375 for (ty, has_destructor) in libtypes.templates_defined.iter() {
1376 write_cpp_wrapper(&mut cpp_header_file, ty, *has_destructor);
1378 writeln!(cpp_header_file, "}}").unwrap();
1380 header_file.flush().unwrap();
1381 cpp_header_file.flush().unwrap();
1382 derived_templates.flush().unwrap();