_ Git - rust-lightning/blob - c-bindings-gen/src/main.rs

   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.
   9 //!
  10 //! It also generates relevant memory-management functions and free-standing functions with
  11 //! parameters mapped.
  12
  13 use std::collections::HashMap;
  14 use std::env;
  15 use std::fs::File;
  16 use std::io::{Read, Write};
  17 use std::path::Path;
  18 use std::process;
  19
  20 use proc_macro2::{TokenTree, TokenStream, Span};
  21
  22 mod types;
  23 mod blocks;
  24 use types::*;
  25 use blocks::*;
  26
  27 // *************************************
  28 // *** Manually-expanded conversions ***
  29 // *************************************
  30
  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(crate) extern \"C\" fn {}_write_void(obj: *const c_void) -> crate::c_types::derived::CVec_u8Z {{", struct_for).unwrap();
  46                                 writeln!(w, "\tcrate::c_types::serialize_obj(unsafe {{ &*(obj as *const native{}) }})", struct_for).unwrap();
  47                                 writeln!(w, "}}").unwrap();
  48                                 writeln!(w, "#[no_mangle]").unwrap();
  49                                 writeln!(w, "pub extern \"C\" fn {}_read(ser: crate::c_types::u8slice) -> {} {{", struct_for, struct_for).unwrap();
  50                                 writeln!(w, "\tif let Ok(res) = crate::c_types::deserialize_obj(ser) {{").unwrap();
  51                                 writeln!(w, "\t\t{} {{ inner: Box::into_raw(Box::new(res)), is_owned: true }}", struct_for).unwrap();
  52                                 writeln!(w, "\t}} else {{").unwrap();
  53                                 writeln!(w, "\t\t{} {{ inner: std::ptr::null_mut(), is_owned: true }}", struct_for).unwrap();
  54                                 writeln!(w, "\t}}\n}}").unwrap();
  55                         }
  56                 },
  57                 _ => {},
  58         }
  59 }
  60
  61 /// Convert "impl trait_path for for_ty { .. }" for manually-mapped types (ie (de)serialization)
  62 fn maybe_convert_trait_impl<W: std::io::Write>(w: &mut W, trait_path: &syn::Path, for_ty: &syn::Type, types: &mut TypeResolver) {
  63         if let Some(t) = types.maybe_resolve_path(&trait_path, None) {
  64                 let for_obj;
  65                 let full_obj_path;
  66                 if let syn::Type::Path(ref p) = for_ty {
  67                         if let Some(ident) = p.path.get_ident() {
  68                                 let s = types.maybe_resolve_ident(ident).unwrap();
  69                                 if !types.crate_types.opaques.get(&s).is_some() { return; }
  70
  71                                 for_obj = format!("{}", ident);
  72                                 full_obj_path = for_obj.clone();
  73                         } else { return; }
  74                 } else {
  75                         return;
  76                 }
  77
  78                 match &t as &str {
  79                         "util::ser::Writeable" => {
  80                                 writeln!(w, "#[no_mangle]").unwrap();
  81                                 writeln!(w, "pub extern \"C\" fn {}_write(obj: *const {}) -> crate::c_types::derived::CVec_u8Z {{", for_obj, full_obj_path).unwrap();
  82                                 writeln!(w, "\tcrate::c_types::serialize_obj(unsafe {{ &(*(*obj).inner) }})").unwrap();
  83                                 writeln!(w, "}}").unwrap();
  84                                 writeln!(w, "#[no_mangle]").unwrap();
  85                                 writeln!(w, "pub(crate) extern \"C\" fn {}_write_void(obj: *const c_void) -> crate::c_types::derived::CVec_u8Z {{", for_obj).unwrap();
  86                                 writeln!(w, "\tcrate::c_types::serialize_obj(unsafe {{ &*(obj as *const native{}) }})", for_obj).unwrap();
  87                                 writeln!(w, "}}").unwrap();
  88                         },
  89                         "util::ser::Readable" => {
  90                                 // Create the Result<Object, DecodeError> syn::Type
  91                                 let mut err_segs = syn::punctuated::Punctuated::new();
  92                                 err_segs.push(syn::PathSegment { ident: syn::Ident::new("ln", Span::call_site()), arguments: syn::PathArguments::None });
  93                                 err_segs.push(syn::PathSegment { ident: syn::Ident::new("msgs", Span::call_site()), arguments: syn::PathArguments::None });
  94                                 err_segs.push(syn::PathSegment { ident: syn::Ident::new("DecodeError", Span::call_site()), arguments: syn::PathArguments::None });
  95                                 let mut args = syn::punctuated::Punctuated::new();
  96                                 args.push(syn::GenericArgument::Type(for_ty.clone()));
  97                                 args.push(syn::GenericArgument::Type(syn::Type::Path(syn::TypePath {
  98                                         qself: None, path: syn::Path {
  99                                                 leading_colon: Some(syn::Token![::](Span::call_site())), segments: err_segs,
 100                                         }
 101                                 })));
 102                                 let mut res_segs = syn::punctuated::Punctuated::new();
 103                                 res_segs.push(syn::PathSegment {
 104                                         ident: syn::Ident::new("Result", Span::call_site()),
 105                                         arguments: syn::PathArguments::AngleBracketed(syn::AngleBracketedGenericArguments {
 106                                                 colon2_token: None, lt_token: syn::Token![<](Span::call_site()), args, gt_token: syn::Token![>](Span::call_site()),
 107                                         })
 108                                 });
 109                                 let res_ty = syn::Type::Path(syn::TypePath { qself: None, path: syn::Path {
 110                                         leading_colon: None, segments: res_segs } });
 111
 112                                 writeln!(w, "#[no_mangle]").unwrap();
 113                                 write!(w, "pub extern \"C\" fn {}_read(ser: crate::c_types::u8slice) -> ", for_obj).unwrap();
 114                                 types.write_c_type(w, &res_ty, None, false);
 115                                 writeln!(w, " {{").unwrap();
 116                                 writeln!(w, "\tlet res = crate::c_types::deserialize_obj(ser);").unwrap();
 117                                 write!(w, "\t").unwrap();
 118                                 if types.write_to_c_conversion_new_var(w, &syn::Ident::new("res", Span::call_site()), &res_ty, None, false) {
 119                                         write!(w, "\n\t").unwrap();
 120                                 }
 121                                 types.write_to_c_conversion_inline_prefix(w, &res_ty, None, false);
 122                                 write!(w, "res").unwrap();
 123                                 types.write_to_c_conversion_inline_suffix(w, &res_ty, None, false);
 124                                 writeln!(w, "\n}}").unwrap();
 125                         },
 126                         _ => {},
 127                 }
 128         }
 129 }
 130
 131 /// Convert "TraitA : TraitB" to a single function name and return type.
 132 ///
 133 /// This is (obviously) somewhat over-specialized and only useful for TraitB's that only require a
 134 /// single function (eg for serialization).
 135 fn convert_trait_impl_field(trait_path: &str) -> (String, &'static str) {
 136         match trait_path {
 137                 "util::ser::Writeable" => ("write".to_owned(), "crate::c_types::derived::CVec_u8Z"),
 138                 _ => unimplemented!(),
 139         }
 140 }
 141
 142 /// Companion to convert_trait_impl_field, write an assignment for the function defined by it for
 143 /// `for_obj` which implements the the trait at `trait_path`.
 144 fn write_trait_impl_field_assign<W: std::io::Write>(w: &mut W, trait_path: &str, for_obj: &syn::Ident) {
 145         match trait_path {
 146                 "util::ser::Writeable" => {
 147                         writeln!(w, "\t\twrite: {}_write_void,", for_obj).unwrap();
 148                 },
 149                 _ => unimplemented!(),
 150         }
 151 }
 152
 153 /// Write out the impl block for a defined trait struct which has a supertrait
 154 fn do_write_impl_trait<W: std::io::Write>(w: &mut W, trait_path: &str, trait_name: &syn::Ident, for_obj: &str) {
 155         match trait_path {
 156                 "util::events::MessageSendEventsProvider" => {
 157                         writeln!(w, "impl lightning::{} for {} {{", trait_path, for_obj).unwrap();
 158                         writeln!(w, "\tfn get_and_clear_pending_msg_events(&self) -> Vec<lightning::util::events::MessageSendEvent> {{").unwrap();
 159                         writeln!(w, "\t\t<crate::{} as lightning::{}>::get_and_clear_pending_msg_events(&self.{})", trait_path, trait_path, trait_name).unwrap();
 160                         writeln!(w, "\t}}\n}}").unwrap();
 161                 },
 162                 "util::ser::Writeable" => {
 163                         writeln!(w, "impl lightning::{} for {} {{", trait_path, for_obj).unwrap();
 164                         writeln!(w, "\tfn write<W: lightning::util::ser::Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {{").unwrap();
 165                         writeln!(w, "\t\tlet vec = (self.write)(self.this_arg);").unwrap();
 166                         writeln!(w, "\t\tw.write_all(vec.as_slice())").unwrap();
 167                         writeln!(w, "\t}}\n}}").unwrap();
 168                 },
 169                 _ => panic!(),
 170         }
 171 }
 172
 173 // *******************************
 174 // *** Per-Type Printing Logic ***
 175 // *******************************
 176
 177 macro_rules! walk_supertraits { ($t: expr, $types: expr, ($( $pat: pat => $e: expr),*) ) => { {
 178         if $t.colon_token.is_some() {
 179                 for st in $t.supertraits.iter() {
 180                         match st {
 181                                 syn::TypeParamBound::Trait(supertrait) => {
 182                                         if supertrait.paren_token.is_some() || supertrait.lifetimes.is_some() {
 183                                                 unimplemented!();
 184                                         }
 185                                         // First try to resolve path to find in-crate traits, but if that doesn't work
 186                                         // assume its a prelude trait (eg Clone, etc) and just use the single ident.
 187                                         if let Some(path) = $types.maybe_resolve_path(&supertrait.path, None) {
 188                                                 match (&path as &str, &supertrait.path.segments.iter().last().unwrap().ident) {
 189                                                         $( $pat => $e, )*
 190                                                 }
 191                                         } else if let Some(ident) = supertrait.path.get_ident() {
 192                                                 match (&format!("{}", ident) as &str, &ident) {
 193                                                         $( $pat => $e, )*
 194                                                 }
 195                                         } else {
 196                                                 panic!("Supertrait unresolvable and not single-ident");
 197                                         }
 198                                 },
 199                                 syn::TypeParamBound::Lifetime(_) => unimplemented!(),
 200                         }
 201                 }
 202         }
 203 } } }
 204
 205 /// Prints a C-mapped trait object containing a void pointer and a jump table for each function in
 206 /// the original trait.
 207 /// Implements the native Rust trait and relevant parent traits for the new C-mapped trait.
 208 ///
 209 /// Finally, implements Deref<MappedTrait> for MappedTrait which allows its use in types which need
 210 /// a concrete Deref to the Rust trait.
 211 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) {
 212         let trait_name = format!("{}", t.ident);
 213         match export_status(&t.attrs) {
 214                 ExportStatus::Export => {},
 215                 ExportStatus::NoExport|ExportStatus::TestOnly => return,
 216         }
 217         writeln_docs(w, &t.attrs, "");
 218
 219         let mut gen_types = GenericTypes::new();
 220         assert!(gen_types.learn_generics(&t.generics, types));
 221         gen_types.learn_associated_types(&t, types);
 222
 223         writeln!(w, "#[repr(C)]\npub struct {} {{", trait_name).unwrap();
 224         writeln!(w, "\tpub this_arg: *mut c_void,").unwrap();
 225         let mut generated_fields = Vec::new(); // Every field's name except this_arg, used in Clone generation
 226         for item in t.items.iter() {
 227                 match item {
 228                         &syn::TraitItem::Method(ref m) => {
 229                                 match export_status(&m.attrs) {
 230                                         ExportStatus::NoExport => {
 231                                                 // NoExport in this context means we'll hit an unimplemented!() at runtime,
 232                                                 // so bail out.
 233                                                 unimplemented!();
 234                                         },
 235                                         ExportStatus::Export => {},
 236                                         ExportStatus::TestOnly => continue,
 237                                 }
 238                                 if m.default.is_some() { unimplemented!(); }
 239
 240                                 gen_types.push_ctx();
 241                                 assert!(gen_types.learn_generics(&m.sig.generics, types));
 242
 243                                 writeln_docs(w, &m.attrs, "\t");
 244
 245                                 if let syn::ReturnType::Type(_, rtype) = &m.sig.output {
 246                                         if let syn::Type::Reference(r) = &**rtype {
 247                                                 // We have to do quite a dance for trait functions which return references
 248                                                 // - they ultimately require us to have a native Rust object stored inside
 249                                                 // our concrete trait to return a reference to. However, users may wish to
 250                                                 // update the value to be returned each time the function is called (or, to
 251                                                 // make C copies of Rust impls equivalent, we have to be able to).
 252                                                 //
 253                                                 // Thus, we store a copy of the C-mapped type (which is just a pointer to
 254                                                 // the Rust type and a flag to indicate whether deallocation needs to
 255                                                 // happen) as well as provide an Option<>al function pointer which is
 256                                                 // called when the trait method is called which allows updating on the fly.
 257                                                 write!(w, "\tpub {}: ", m.sig.ident).unwrap();
 258                                                 generated_fields.push(format!("{}", m.sig.ident));
 259                                                 types.write_c_type(w, &*r.elem, Some(&gen_types), false);
 260                                                 writeln!(w, ",").unwrap();
 261                                                 writeln!(w, "\t/// Fill in the {} field as a reference to it will be given to Rust after this returns", m.sig.ident).unwrap();
 262                                                 writeln!(w, "\t/// Note that this takes a pointer to this object, not the this_ptr like other methods do").unwrap();
 263                                                 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();
 264                                                 writeln!(w, "\tpub set_{}: Option<extern \"C\" fn(&{})>,", m.sig.ident, trait_name).unwrap();
 265                                                 generated_fields.push(format!("set_{}", m.sig.ident));
 266                                                 // Note that cbindgen will now generate
 267                                                 // typedef struct Thing {..., set_thing: (const Thing*), ...} Thing;
 268                                                 // which does not compile since Thing is not defined before it is used.
 269                                                 writeln!(extra_headers, "struct LDK{};", trait_name).unwrap();
 270                                                 writeln!(extra_headers, "typedef struct LDK{} LDK{};", trait_name, trait_name).unwrap();
 271                                                 gen_types.pop_ctx();
 272                                                 continue;
 273                                         }
 274                                         // Sadly, this currently doesn't do what we want, but it should be easy to get
 275                                         // cbindgen to support it. See https://github.com/eqrion/cbindgen/issues/531
 276                                         writeln!(w, "\t#[must_use]").unwrap();
 277                                 }
 278
 279                                 write!(w, "\tpub {}: extern \"C\" fn (", m.sig.ident).unwrap();
 280                                 generated_fields.push(format!("{}", m.sig.ident));
 281                                 write_method_params(w, &m.sig, "c_void", types, Some(&gen_types), true, false);
 282                                 writeln!(w, ",").unwrap();
 283
 284                                 gen_types.pop_ctx();
 285                         },
 286                         &syn::TraitItem::Type(_) => {},
 287                         _ => unimplemented!(),
 288                 }
 289         }
 290         // Add functions which may be required for supertrait implementations.
 291         walk_supertraits!(t, types, (
 292                 ("Clone", _) => {
 293                         writeln!(w, "\tpub clone: Option<extern \"C\" fn (this_arg: *const c_void) -> *mut c_void>,").unwrap();
 294                         generated_fields.push("clone".to_owned());
 295                 },
 296                 ("std::cmp::Eq", _) => {
 297                         writeln!(w, "\tpub eq: extern \"C\" fn (this_arg: *const c_void, other_arg: &{}) -> bool,", trait_name).unwrap();
 298                         writeln!(extra_headers, "typedef struct LDK{} LDK{};", trait_name, trait_name).unwrap();
 299                         generated_fields.push("eq".to_owned());
 300                 },
 301                 ("std::hash::Hash", _) => {
 302                         writeln!(w, "\tpub hash: extern \"C\" fn (this_arg: *const c_void) -> u64,").unwrap();
 303                         generated_fields.push("hash".to_owned());
 304                 },
 305                 ("Send", _) => {}, ("Sync", _) => {},
 306                 (s, i) => {
 307                         generated_fields.push(if types.crate_types.traits.get(s).is_none() {
 308                                 let (name, ret) = convert_trait_impl_field(s);
 309                                 writeln!(w, "\tpub {}: extern \"C\" fn (this_arg: *const c_void) -> {},", name, ret).unwrap();
 310                                 name
 311                         } else {
 312                                 // For in-crate supertraits, just store a C-mapped copy of the supertrait as a member.
 313                                 writeln!(w, "\tpub {}: crate::{},", i, s).unwrap();
 314                                 format!("{}", i)
 315                         });
 316                 }
 317         ) );
 318         writeln!(w, "\tpub free: Option<extern \"C\" fn(this_arg: *mut c_void)>,").unwrap();
 319         generated_fields.push("free".to_owned());
 320         writeln!(w, "}}").unwrap();
 321         // Implement supertraits for the C-mapped struct.
 322         walk_supertraits!(t, types, (
 323                 ("Send", _) => writeln!(w, "unsafe impl Send for {} {{}}", trait_name).unwrap(),
 324                 ("Sync", _) => writeln!(w, "unsafe impl Sync for {} {{}}", trait_name).unwrap(),
 325                 ("std::cmp::Eq", _) => {
 326                         writeln!(w, "impl std::cmp::Eq for {} {{}}", trait_name).unwrap();
 327                         writeln!(w, "impl std::cmp::PartialEq for {} {{", trait_name).unwrap();
 328                         writeln!(w, "\tfn eq(&self, o: &Self) -> bool {{ (self.eq)(self.this_arg, o) }}\n}}").unwrap();
 329                 },
 330                 ("std::hash::Hash", _) => {
 331                         writeln!(w, "impl std::hash::Hash for {} {{", trait_name).unwrap();
 332                         writeln!(w, "\tfn hash<H: std::hash::Hasher>(&self, hasher: &mut H) {{ hasher.write_u64((self.hash)(self.this_arg)) }}\n}}").unwrap();
 333                 },
 334                 ("Clone", _) => {
 335                         writeln!(w, "#[no_mangle]").unwrap();
 336                         writeln!(w, "pub extern \"C\" fn {}_clone(orig: &{}) -> {} {{", trait_name, trait_name, trait_name).unwrap();
 337                         writeln!(w, "\t{} {{", trait_name).unwrap();
 338                         writeln!(w, "\t\tthis_arg: if let Some(f) = orig.clone {{ (f)(orig.this_arg) }} else {{ orig.this_arg }},").unwrap();
 339                         for field in generated_fields.iter() {
 340                                 writeln!(w, "\t\t{}: orig.{}.clone(),", field, field).unwrap();
 341                         }
 342                         writeln!(w, "\t}}\n}}").unwrap();
 343                         writeln!(w, "impl Clone for {} {{", trait_name).unwrap();
 344                         writeln!(w, "\tfn clone(&self) -> Self {{").unwrap();
 345                         writeln!(w, "\t\t{}_clone(self)", trait_name).unwrap();
 346                         writeln!(w, "\t}}\n}}").unwrap();
 347                 },
 348                 (s, i) => {
 349                         do_write_impl_trait(w, s, i, &trait_name);
 350                 }
 351         ) );
 352
 353         // Finally, implement the original Rust trait for the newly created mapped trait.
 354         writeln!(w, "\nuse {}::{}::{} as rust{};", types.orig_crate, types.module_path, t.ident, trait_name).unwrap();
 355         write!(w, "impl rust{}", t.ident).unwrap();
 356         maybe_write_generics(w, &t.generics, types, false);
 357         writeln!(w, " for {} {{", trait_name).unwrap();
 358         for item in t.items.iter() {
 359                 match item {
 360                         syn::TraitItem::Method(m) => {
 361                                 if let ExportStatus::TestOnly = export_status(&m.attrs) { continue; }
 362                                 if m.default.is_some() { unimplemented!(); }
 363                                 if m.sig.constness.is_some() || m.sig.asyncness.is_some() || m.sig.unsafety.is_some() ||
 364                                                 m.sig.abi.is_some() || m.sig.variadic.is_some() {
 365                                         unimplemented!();
 366                                 }
 367                                 gen_types.push_ctx();
 368                                 assert!(gen_types.learn_generics(&m.sig.generics, types));
 369                                 write!(w, "\tfn {}", m.sig.ident).unwrap();
 370                                 types.write_rust_generic_param(w, Some(&gen_types), m.sig.generics.params.iter());
 371                                 write!(w, "(").unwrap();
 372                                 for inp in m.sig.inputs.iter() {
 373                                         match inp {
 374                                                 syn::FnArg::Receiver(recv) => {
 375                                                         if !recv.attrs.is_empty() || recv.reference.is_none() { unimplemented!(); }
 376                                                         write!(w, "&").unwrap();
 377                                                         if let Some(lft) = &recv.reference.as_ref().unwrap().1 {
 378                                                                 write!(w, "'{} ", lft.ident).unwrap();
 379                                                         }
 380                                                         if recv.mutability.is_some() {
 381                                                                 write!(w, "mut self").unwrap();
 382                                                         } else {
 383                                                                 write!(w, "self").unwrap();
 384                                                         }
 385                                                 },
 386                                                 syn::FnArg::Typed(arg) => {
 387                                                         if !arg.attrs.is_empty() { unimplemented!(); }
 388                                                         match &*arg.pat {
 389                                                                 syn::Pat::Ident(ident) => {
 390                                                                         if !ident.attrs.is_empty() || ident.by_ref.is_some() ||
 391                                                                                         ident.mutability.is_some() || ident.subpat.is_some() {
 392                                                                                 unimplemented!();
 393                                                                         }
 394                                                                         write!(w, ", {}{}: ", if types.skip_arg(&*arg.ty, Some(&gen_types)) { "_" } else { "" }, ident.ident).unwrap();
 395                                                                 }
 396                                                                 _ => unimplemented!(),
 397                                                         }
 398                                                         types.write_rust_type(w, Some(&gen_types), &*arg.ty);
 399                                                 }
 400                                         }
 401                                 }
 402                                 write!(w, ")").unwrap();
 403                                 match &m.sig.output {
 404                                         syn::ReturnType::Type(_, rtype) => {
 405                                                 write!(w, " -> ").unwrap();
 406                                                 types.write_rust_type(w, Some(&gen_types), &*rtype)
 407                                         },
 408                                         _ => {},
 409                                 }
 410                                 write!(w, " {{\n\t\t").unwrap();
 411                                 match export_status(&m.attrs) {
 412                                         ExportStatus::NoExport => {
 413                                                 unimplemented!();
 414                                         },
 415                                         _ => {},
 416                                 }
 417                                 if let syn::ReturnType::Type(_, rtype) = &m.sig.output {
 418                                         if let syn::Type::Reference(r) = &**rtype {
 419                                                 assert_eq!(m.sig.inputs.len(), 1); // Must only take self!
 420                                                 writeln!(w, "if let Some(f) = self.set_{} {{", m.sig.ident).unwrap();
 421                                                 writeln!(w, "\t\t\t(f)(self);").unwrap();
 422                                                 write!(w, "\t\t}}\n\t\t").unwrap();
 423                                                 types.write_from_c_conversion_to_ref_prefix(w, &*r.elem, Some(&gen_types));
 424                                                 write!(w, "self.{}", m.sig.ident).unwrap();
 425                                                 types.write_from_c_conversion_to_ref_suffix(w, &*r.elem, Some(&gen_types));
 426                                                 writeln!(w, "\n\t}}").unwrap();
 427                                                 gen_types.pop_ctx();
 428                                                 continue;
 429                                         }
 430                                 }
 431                                 write_method_var_decl_body(w, &m.sig, "\t", types, Some(&gen_types), true);
 432                                 write!(w, "(self.{})(", m.sig.ident).unwrap();
 433                                 write_method_call_params(w, &m.sig, "\t", types, Some(&gen_types), "", true);
 434
 435                                 writeln!(w, "\n\t}}").unwrap();
 436                                 gen_types.pop_ctx();
 437                         },
 438                         &syn::TraitItem::Type(ref t) => {
 439                                 if t.default.is_some() || t.generics.lt_token.is_some() { unimplemented!(); }
 440                                 let mut bounds_iter = t.bounds.iter();
 441                                 match bounds_iter.next().unwrap() {
 442                                         syn::TypeParamBound::Trait(tr) => {
 443                                                 writeln!(w, "\ttype {} = crate::{};", t.ident, types.resolve_path(&tr.path, Some(&gen_types))).unwrap();
 444                                         },
 445                                         _ => unimplemented!(),
 446                                 }
 447                                 if bounds_iter.next().is_some() { unimplemented!(); }
 448                         },
 449                         _ => unimplemented!(),
 450                 }
 451         }
 452         writeln!(w, "}}\n").unwrap();
 453         writeln!(w, "// We're essentially a pointer already, or at least a set of pointers, so allow us to be used").unwrap();
 454         writeln!(w, "// directly as a Deref trait in higher-level structs:").unwrap();
 455         writeln!(w, "impl std::ops::Deref for {} {{\n\ttype Target = Self;", trait_name).unwrap();
 456         writeln!(w, "\tfn deref(&self) -> &Self {{\n\t\tself\n\t}}\n}}").unwrap();
 457
 458         writeln!(w, "/// Calls the free function if one is set").unwrap();
 459         writeln!(w, "#[no_mangle]\npub extern \"C\" fn {}_free(this_ptr: {}) {{ }}", trait_name, trait_name).unwrap();
 460         writeln!(w, "impl Drop for {} {{", trait_name).unwrap();
 461         writeln!(w, "\tfn drop(&mut self) {{").unwrap();
 462         writeln!(w, "\t\tif let Some(f) = self.free {{").unwrap();
 463         writeln!(w, "\t\t\tf(self.this_arg);").unwrap();
 464         writeln!(w, "\t\t}}\n\t}}\n}}").unwrap();
 465
 466         write_cpp_wrapper(cpp_headers, &trait_name, true);
 467         types.trait_declared(&t.ident, t);
 468 }
 469
 470 /// Write out a simple "opaque" type (eg structs) which contain a pointer to the native Rust type
 471 /// and a flag to indicate whether Drop'ing the mapped struct drops the underlying Rust type.
 472 ///
 473 /// Also writes out a _free function and a C++ wrapper which handles calling _free.
 474 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) {
 475         // If we directly read the original type by its original name, cbindgen hits
 476         // https://github.com/eqrion/cbindgen/issues/286 Thus, instead, we import it as a temporary
 477         // name and then reference it by that name, which works around the issue.
 478         write!(w, "\nuse {}::{}::{} as native{}Import;\ntype native{} = native{}Import", types.orig_crate, types.module_path, ident, ident, ident, ident).unwrap();
 479         maybe_write_generics(w, &generics, &types, true);
 480         writeln!(w, ";\n").unwrap();
 481         writeln!(extra_headers, "struct native{}Opaque;\ntypedef struct native{}Opaque LDKnative{};", ident, ident, ident).unwrap();
 482         writeln_docs(w, &attrs, "");
 483         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();
 484         writeln!(w, "\t/// the Rust equivalent takes an Option, it may be set to null to indicate None.").unwrap();
 485         writeln!(w, "\tpub inner: *mut native{},\n\tpub is_owned: bool,\n}}\n", ident).unwrap();
 486         writeln!(w, "impl Drop for {} {{\n\tfn drop(&mut self) {{", struct_name).unwrap();
 487         writeln!(w, "\t\tif self.is_owned && !self.inner.is_null() {{").unwrap();
 488         writeln!(w, "\t\t\tlet _ = unsafe {{ Box::from_raw(self.inner) }};\n\t\t}}\n\t}}\n}}").unwrap();
 489         writeln!(w, "#[no_mangle]\npub extern \"C\" fn {}_free(this_ptr: {}) {{ }}", struct_name, struct_name).unwrap();
 490         writeln!(w, "#[allow(unused)]").unwrap();
 491         writeln!(w, "/// Used only if an object of this type is returned as a trait impl by a method").unwrap();
 492         writeln!(w, "extern \"C\" fn {}_free_void(this_ptr: *mut c_void) {{", struct_name).unwrap();
 493         writeln!(w, "\tunsafe {{ let _ = Box::from_raw(this_ptr as *mut native{}); }}\n}}", struct_name).unwrap();
 494         writeln!(w, "#[allow(unused)]").unwrap();
 495         writeln!(w, "/// When moving out of the pointer, we have to ensure we aren't a reference, this makes that easy").unwrap();
 496         writeln!(w, "impl {} {{", struct_name).unwrap();
 497         writeln!(w, "\tpub(crate) fn take_inner(mut self) -> *mut native{} {{", struct_name).unwrap();
 498         writeln!(w, "\t\tassert!(self.is_owned);").unwrap();
 499         writeln!(w, "\t\tlet ret = self.inner;").unwrap();
 500         writeln!(w, "\t\tself.inner = std::ptr::null_mut();").unwrap();
 501         writeln!(w, "\t\tret").unwrap();
 502         writeln!(w, "\t}}\n}}").unwrap();
 503
 504         'attr_loop: for attr in attrs.iter() {
 505                 let tokens_clone = attr.tokens.clone();
 506                 let mut token_iter = tokens_clone.into_iter();
 507                 if let Some(token) = token_iter.next() {
 508                         match token {
 509                                 TokenTree::Group(g) => {
 510                                         if format!("{}", single_ident_generic_path_to_ident(&attr.path).unwrap()) == "derive" {
 511                                                 for id in g.stream().into_iter() {
 512                                                         if let TokenTree::Ident(i) = id {
 513                                                                 if i == "Clone" {
 514                                                                         writeln!(w, "impl Clone for {} {{", struct_name).unwrap();
 515                                                                         writeln!(w, "\tfn clone(&self) -> Self {{").unwrap();
 516                                                                         writeln!(w, "\t\tSelf {{").unwrap();
 517                                                                         writeln!(w, "\t\t\tinner: Box::into_raw(Box::new(unsafe {{ &*self.inner }}.clone())),").unwrap();
 518                                                                         writeln!(w, "\t\t\tis_owned: true,").unwrap();
 519                                                                         writeln!(w, "\t\t}}\n\t}}\n}}").unwrap();
 520                                                                         writeln!(w, "#[allow(unused)]").unwrap();
 521                                                                         writeln!(w, "/// Used only if an object of this type is returned as a trait impl by a method").unwrap();
 522                                                                         writeln!(w, "pub(crate) extern \"C\" fn {}_clone_void(this_ptr: *const c_void) -> *mut c_void {{", struct_name).unwrap();
 523                                                                         writeln!(w, "\tBox::into_raw(Box::new(unsafe {{ (*(this_ptr as *mut native{})).clone() }})) as *mut c_void", struct_name).unwrap();
 524                                                                         writeln!(w, "}}").unwrap();
 525                                                                         writeln!(w, "#[no_mangle]").unwrap();
 526                                                                         writeln!(w, "pub extern \"C\" fn {}_clone(orig: &{}) -> {} {{", struct_name, struct_name, struct_name).unwrap();
 527                                                                         writeln!(w, "\t{} {{ inner: Box::into_raw(Box::new(unsafe {{ &*orig.inner }}.clone())), is_owned: true }}", struct_name).unwrap();
 528                                                                         writeln!(w, "}}").unwrap();
 529                                                                         break 'attr_loop;
 530                                                                 }
 531                                                         }
 532                                                 }
 533                                         }
 534                                 },
 535                                 _ => {},
 536                         }
 537                 }
 538         }
 539
 540         write_cpp_wrapper(cpp_headers, &format!("{}", ident), true);
 541 }
 542
 543 fn declare_struct<'a, 'b>(s: &'a syn::ItemStruct, types: &mut TypeResolver<'b, 'a>) -> bool {
 544         let export = export_status(&s.attrs);
 545         match export {
 546                 ExportStatus::Export => {},
 547                 ExportStatus::TestOnly => return false,
 548                 ExportStatus::NoExport => {
 549                         types.struct_ignored(&s.ident);
 550                         return false;
 551                 }
 552         }
 553
 554         types.struct_imported(&s.ident, format!("{}", s.ident));
 555         true
 556 }
 557
 558 /// Writes out all the relevant mappings for a Rust struct, deferring to writeln_opaque to generate
 559 /// the struct itself, and then writing getters and setters for public, understood-type fields and
 560 /// a constructor if every field is public.
 561 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) {
 562         if !declare_struct(s, types) { return; }
 563
 564         let struct_name = &format!("{}", s.ident);
 565         writeln_opaque(w, &s.ident, struct_name, &s.generics, &s.attrs, types, extra_headers, cpp_headers);
 566
 567         eprintln!("exporting fields for {}", struct_name);
 568         if let syn::Fields::Named(fields) = &s.fields {
 569                 let mut gen_types = GenericTypes::new();
 570                 assert!(gen_types.learn_generics(&s.generics, types));
 571
 572                 let mut all_fields_settable = true;
 573                 for field in fields.named.iter() {
 574                         if let syn::Visibility::Public(_) = field.vis {
 575                                 let export = export_status(&field.attrs);
 576                                 match export {
 577                                         ExportStatus::Export => {},
 578                                         ExportStatus::NoExport|ExportStatus::TestOnly => {
 579                                                 all_fields_settable = false;
 580                                                 continue
 581                                         },
 582                                 }
 583
 584                                 if let Some(ident) = &field.ident {
 585                                         let ref_type = syn::Type::Reference(syn::TypeReference {
 586                                                 and_token: syn::Token!(&)(Span::call_site()), lifetime: None, mutability: None,
 587                                                 elem: Box::new(field.ty.clone()) });
 588                                         if types.understood_c_type(&ref_type, Some(&gen_types)) {
 589                                                 writeln_docs(w, &field.attrs, "");
 590                                                 write!(w, "#[no_mangle]\npub extern \"C\" fn {}_get_{}(this_ptr: &{}) -> ", struct_name, ident, struct_name).unwrap();
 591                                                 types.write_c_type(w, &ref_type, Some(&gen_types), true);
 592                                                 write!(w, " {{\n\tlet mut inner_val = &mut unsafe {{ &mut *this_ptr.inner }}.{};\n\t", ident).unwrap();
 593                                                 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);
 594                                                 if local_var { write!(w, "\n\t").unwrap(); }
 595                                                 types.write_to_c_conversion_inline_prefix(w, &ref_type, Some(&gen_types), true);
 596                                                 if local_var {
 597                                                         write!(w, "inner_val").unwrap();
 598                                                 } else {
 599                                                         write!(w, "(*inner_val)").unwrap();
 600                                                 }
 601                                                 types.write_to_c_conversion_inline_suffix(w, &ref_type, Some(&gen_types), true);
 602                                                 writeln!(w, "\n}}").unwrap();
 603                                         }
 604
 605                                         if types.understood_c_type(&field.ty, Some(&gen_types)) {
 606                                                 writeln_docs(w, &field.attrs, "");
 607                                                 write!(w, "#[no_mangle]\npub extern \"C\" fn {}_set_{}(this_ptr: &mut {}, mut val: ", struct_name, ident, struct_name).unwrap();
 608                                                 types.write_c_type(w, &field.ty, Some(&gen_types), false);
 609                                                 write!(w, ") {{\n\t").unwrap();
 610                                                 let local_var = types.write_from_c_conversion_new_var(w, &syn::Ident::new("val", Span::call_site()), &field.ty, Some(&gen_types));
 611                                                 if local_var { write!(w, "\n\t").unwrap(); }
 612                                                 write!(w, "unsafe {{ &mut *this_ptr.inner }}.{} = ", ident).unwrap();
 613                                                 types.write_from_c_conversion_prefix(w, &field.ty, Some(&gen_types));
 614                                                 write!(w, "val").unwrap();
 615                                                 types.write_from_c_conversion_suffix(w, &field.ty, Some(&gen_types));
 616                                                 writeln!(w, ";\n}}").unwrap();
 617                                         } else { all_fields_settable = false; }
 618                                 } else { all_fields_settable = false; }
 619                         } else { all_fields_settable = false; }
 620                 }
 621
 622                 if all_fields_settable {
 623                         // Build a constructor!
 624                         write!(w, "#[must_use]\n#[no_mangle]\npub extern \"C\" fn {}_new(", struct_name).unwrap();
 625                         for (idx, field) in fields.named.iter().enumerate() {
 626                                 if idx != 0 { write!(w, ", ").unwrap(); }
 627                                 write!(w, "mut {}_arg: ", field.ident.as_ref().unwrap()).unwrap();
 628                                 types.write_c_type(w, &field.ty, Some(&gen_types), false);
 629                         }
 630                         write!(w, ") -> {} {{\n\t", struct_name).unwrap();
 631                         for field in fields.named.iter() {
 632                                 let field_name = format!("{}_arg", field.ident.as_ref().unwrap());
 633                                 if types.write_from_c_conversion_new_var(w, &syn::Ident::new(&field_name, Span::call_site()), &field.ty, Some(&gen_types)) {
 634                                         write!(w, "\n\t").unwrap();
 635                                 }
 636                         }
 637                         writeln!(w, "{} {{ inner: Box::into_raw(Box::new(native{} {{", struct_name, s.ident).unwrap();
 638                         for field in fields.named.iter() {
 639                                 write!(w, "\t\t{}: ", field.ident.as_ref().unwrap()).unwrap();
 640                                 types.write_from_c_conversion_prefix(w, &field.ty, Some(&gen_types));
 641                                 write!(w, "{}_arg", field.ident.as_ref().unwrap()).unwrap();
 642                                 types.write_from_c_conversion_suffix(w, &field.ty, Some(&gen_types));
 643                                 writeln!(w, ",").unwrap();
 644                         }
 645                         writeln!(w, "\t}})), is_owned: true }}\n}}").unwrap();
 646                 }
 647         }
 648 }
 649
 650 /// Prints a relevant conversion for impl *
 651 ///
 652 /// For simple impl Struct {}s, this just outputs the wrapper functions as Struct_fn_name() { .. }.
 653 ///
 654 /// For impl Trait for Struct{}s, this non-exported generates wrapper functions as
 655 /// Trait_Struct_fn_name and a Struct_as_Trait(&struct) -> Trait function which returns a populated
 656 /// Trait struct containing a pointer to the passed struct's inner field and the wrapper functions.
 657 ///
 658 /// A few non-crate Traits are hard-coded including Default.
 659 fn writeln_impl<W: std::io::Write>(w: &mut W, i: &syn::ItemImpl, types: &mut TypeResolver) {
 660         if let &syn::Type::Path(ref p) = &*i.self_ty {
 661                 if p.qself.is_some() { unimplemented!(); }
 662                 if let Some(ident) = single_ident_generic_path_to_ident(&p.path) {
 663                         if let Some(resolved_path) = types.maybe_resolve_non_ignored_ident(&ident) {
 664                                 let mut gen_types = GenericTypes::new();
 665                                 if !gen_types.learn_generics(&i.generics, types) {
 666                                         eprintln!("Not implementing anything for impl {} due to not understood generics", ident);
 667                                         return;
 668                                 }
 669
 670                                 if i.defaultness.is_some() || i.unsafety.is_some() { unimplemented!(); }
 671                                 if let Some(trait_path) = i.trait_.as_ref() {
 672                                         if trait_path.0.is_some() { unimplemented!(); }
 673                                         if types.understood_c_path(&trait_path.1) {
 674                                                 let full_trait_path = types.resolve_path(&trait_path.1, None);
 675                                                 let trait_obj = *types.crate_types.traits.get(&full_trait_path).unwrap();
 676                                                 // We learn the associated types maping from the original trait object.
 677                                                 // That's great, except that they are unresolved idents, so if we learn
 678                                                 // mappings from a trai defined in a different file, we may mis-resolve or
 679                                                 // fail to resolve the mapped types.
 680                                                 gen_types.learn_associated_types(trait_obj, types);
 681                                                 let mut impl_associated_types = HashMap::new();
 682                                                 for item in i.items.iter() {
 683                                                         match item {
 684                                                                 syn::ImplItem::Type(t) => {
 685                                                                         if let syn::Type::Path(p) = &t.ty {
 686                                                                                 if let Some(id) = single_ident_generic_path_to_ident(&p.path) {
 687                                                                                         impl_associated_types.insert(&t.ident, id);
 688                                                                                 }
 689                                                                         }
 690                                                                 },
 691                                                                 _ => {},
 692                                                         }
 693                                                 }
 694
 695                                                 let export = export_status(&trait_obj.attrs);
 696                                                 match export {
 697                                                         ExportStatus::Export => {},
 698                                                         ExportStatus::NoExport|ExportStatus::TestOnly => return,
 699                                                 }
 700
 701                                                 // For cases where we have a concrete native object which implements a
 702                                                 // trait and need to return the C-mapped version of the trait, provide a
 703                                                 // From<> implementation which does all the work to ensure free is handled
 704                                                 // properly. This way we can call this method from deep in the
 705                                                 // type-conversion logic without actually knowing the concrete native type.
 706                                                 writeln!(w, "impl From<native{}> for crate::{} {{", ident, full_trait_path).unwrap();
 707                                                 writeln!(w, "\tfn from(obj: native{}) -> Self {{", ident).unwrap();
 708                                                 writeln!(w, "\t\tlet mut rust_obj = {} {{ inner: Box::into_raw(Box::new(obj)), is_owned: true }};", ident).unwrap();
 709                                                 writeln!(w, "\t\tlet mut ret = {}_as_{}(&rust_obj);", ident, trait_obj.ident).unwrap();
 710                                                 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();
 711                                                 writeln!(w, "\t\trust_obj.inner = std::ptr::null_mut();").unwrap();
 712                                                 writeln!(w, "\t\tret.free = Some({}_free_void);", ident).unwrap();
 713                                                 writeln!(w, "\t\tret\n\t}}\n}}").unwrap();
 714
 715                                                 write!(w, "#[no_mangle]\npub extern \"C\" fn {}_as_{}(this_arg: *const {}) -> crate::{} {{\n", ident, trait_obj.ident, ident, full_trait_path).unwrap();
 716                                                 writeln!(w, "\tcrate::{} {{", full_trait_path).unwrap();
 717                                                 writeln!(w, "\t\tthis_arg: unsafe {{ (*this_arg).inner as *mut c_void }},").unwrap();
 718                                                 writeln!(w, "\t\tfree: None,").unwrap();
 719
 720                                                 macro_rules! write_meth {
 721                                                         ($m: expr, $trait: expr, $indent: expr) => {
 722                                                                 let trait_method = $trait.items.iter().filter_map(|item| {
 723                                                                         if let syn::TraitItem::Method(t_m) = item { Some(t_m) } else { None }
 724                                                                 }).find(|trait_meth| trait_meth.sig.ident == $m.sig.ident).unwrap();
 725                                                                 match export_status(&trait_method.attrs) {
 726                                                                         ExportStatus::Export => {},
 727                                                                         ExportStatus::NoExport => {
 728                                                                                 write!(w, "{}\t\t//XXX: Need to export {}\n", $indent, $m.sig.ident).unwrap();
 729                                                                                 continue;
 730                                                                         },
 731                                                                         ExportStatus::TestOnly => continue,
 732                                                                 }
 733
 734                                                                 let mut printed = false;
 735                                                                 if let syn::ReturnType::Type(_, rtype) = &$m.sig.output {
 736                                                                         if let syn::Type::Reference(r) = &**rtype {
 737                                                                                 write!(w, "\n\t\t{}{}: ", $indent, $m.sig.ident).unwrap();
 738                                                                                 types.write_empty_rust_val(Some(&gen_types), w, &*r.elem);
 739                                                                                 writeln!(w, ",\n{}\t\tset_{}: Some({}_{}_set_{}),", $indent, $m.sig.ident, ident, trait_obj.ident, $m.sig.ident).unwrap();
 740                                                                                 printed = true;
 741                                                                         }
 742                                                                 }
 743                                                                 if !printed {
 744                                                                         write!(w, "{}\t\t{}: {}_{}_{},\n", $indent, $m.sig.ident, ident, trait_obj.ident, $m.sig.ident).unwrap();
 745                                                                 }
 746                                                         }
 747                                                 }
 748                                                 for item in trait_obj.items.iter() {
 749                                                         match item {
 750                                                                 syn::TraitItem::Method(m) => {
 751                                                                         write_meth!(m, trait_obj, "");
 752                                                                 },
 753                                                                 _ => {},
 754                                                         }
 755                                                 }
 756                                                 walk_supertraits!(trait_obj, types, (
 757                                                         ("Clone", _) => {
 758                                                                 writeln!(w, "\t\tclone: Some({}_clone_void),", ident).unwrap();
 759                                                         },
 760                                                         ("Sync", _) => {}, ("Send", _) => {},
 761                                                         ("std::marker::Sync", _) => {}, ("std::marker::Send", _) => {},
 762                                                         (s, t) => {
 763                                                                 if let Some(supertrait_obj) = types.crate_types.traits.get(s) {
 764                                                                         writeln!(w, "\t\t{}: crate::{} {{", t, s).unwrap();
 765                                                                         writeln!(w, "\t\t\tthis_arg: unsafe {{ (*this_arg).inner as *mut c_void }},").unwrap();
 766                                                                         writeln!(w, "\t\t\tfree: None,").unwrap();
 767                                                                         for item in supertrait_obj.items.iter() {
 768                                                                                 match item {
 769                                                                                         syn::TraitItem::Method(m) => {
 770                                                                                                 write_meth!(m, supertrait_obj, "\t");
 771                                                                                         },
 772                                                                                         _ => {},
 773                                                                                 }
 774                                                                         }
 775                                                                         write!(w, "\t\t}},\n").unwrap();
 776                                                                 } else {
 777                                                                         write_trait_impl_field_assign(w, s, ident);
 778                                                                 }
 779                                                         }
 780                                                 ) );
 781                                                 write!(w, "\t}}\n}}\nuse {}::{} as {}TraitImport;\n", types.orig_crate, full_trait_path, trait_obj.ident).unwrap();
 782
 783                                                 macro_rules! impl_meth {
 784                                                         ($m: expr, $trait: expr, $indent: expr) => {
 785                                                                 let trait_method = $trait.items.iter().filter_map(|item| {
 786                                                                         if let syn::TraitItem::Method(t_m) = item { Some(t_m) } else { None }
 787                                                                 }).find(|trait_meth| trait_meth.sig.ident == $m.sig.ident).unwrap();
 788                                                                 match export_status(&trait_method.attrs) {
 789                                                                         ExportStatus::Export => {},
 790                                                                         ExportStatus::NoExport|ExportStatus::TestOnly => continue,
 791                                                                 }
 792
 793                                                                 if let syn::ReturnType::Type(_, _) = &$m.sig.output {
 794                                                                         writeln!(w, "#[must_use]").unwrap();
 795                                                                 }
 796                                                                 write!(w, "extern \"C\" fn {}_{}_{}(", ident, trait_obj.ident, $m.sig.ident).unwrap();
 797                                                                 gen_types.push_ctx();
 798                                                                 assert!(gen_types.learn_generics(&$m.sig.generics, types));
 799                                                                 write_method_params(w, &$m.sig, "c_void", types, Some(&gen_types), true, true);
 800                                                                 write!(w, " {{\n\t").unwrap();
 801                                                                 write_method_var_decl_body(w, &$m.sig, "", types, Some(&gen_types), false);
 802                                                                 let mut takes_self = false;
 803                                                                 for inp in $m.sig.inputs.iter() {
 804                                                                         if let syn::FnArg::Receiver(_) = inp {
 805                                                                                 takes_self = true;
 806                                                                         }
 807                                                                 }
 808                                                                 if takes_self {
 809                                                                         write!(w, "unsafe {{ &mut *(this_arg as *mut native{}) }}.{}(", ident, $m.sig.ident).unwrap();
 810                                                                 } else {
 811                                                                         write!(w, "{}::{}::{}(", types.orig_crate, resolved_path, $m.sig.ident).unwrap();
 812                                                                 }
 813
 814                                                                 let mut real_type = "".to_string();
 815                                                                 match &$m.sig.output {
 816                                                                         syn::ReturnType::Type(_, rtype) => {
 817                                                                                 if let Some(mut remaining_path) = first_seg_self(&*rtype) {
 818                                                                                         if let Some(associated_seg) = get_single_remaining_path_seg(&mut remaining_path) {
 819                                                                                                 real_type = format!("{}", impl_associated_types.get(associated_seg).unwrap());
 820                                                                                         }
 821                                                                                 }
 822                                                                         },
 823                                                                         _ => {},
 824                                                                 }
 825                                                                 write_method_call_params(w, &$m.sig, "", types, Some(&gen_types), &real_type, false);
 826                                                                 gen_types.pop_ctx();
 827                                                                 write!(w, "\n}}\n").unwrap();
 828                                                                 if let syn::ReturnType::Type(_, rtype) = &$m.sig.output {
 829                                                                         if let syn::Type::Reference(r) = &**rtype {
 830                                                                                 assert_eq!($m.sig.inputs.len(), 1); // Must only take self
 831                                                                                 writeln!(w, "extern \"C\" fn {}_{}_set_{}(trait_self_arg: &{}) {{", ident, trait_obj.ident, $m.sig.ident, trait_obj.ident).unwrap();
 832                                                                                 writeln!(w, "\t// This is a bit race-y in the general case, but for our specific use-cases today, we're safe").unwrap();
 833                                                                                 writeln!(w, "\t// Specifically, we must ensure that the first time we're called it can never be in parallel").unwrap();
 834                                                                                 write!(w, "\tif ").unwrap();
 835                                                                                 types.write_empty_rust_val_check(Some(&gen_types), w, &*r.elem, &format!("trait_self_arg.{}", $m.sig.ident));
 836                                                                                 writeln!(w, " {{").unwrap();
 837                                                                                 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();
 838                                                                                 writeln!(w, "\t}}").unwrap();
 839                                                                                 writeln!(w, "}}").unwrap();
 840                                                                         }
 841                                                                 }
 842                                                         }
 843                                                 }
 844
 845                                                 for item in i.items.iter() {
 846                                                         match item {
 847                                                                 syn::ImplItem::Method(m) => {
 848                                                                         impl_meth!(m, trait_obj, "");
 849                                                                 },
 850                                                                 syn::ImplItem::Type(_) => {},
 851                                                                 _ => unimplemented!(),
 852                                                         }
 853                                                 }
 854                                                 walk_supertraits!(trait_obj, types, (
 855                                                         (s, t) => {
 856                                                                 if let Some(supertrait_obj) = types.crate_types.traits.get(s).cloned() {
 857                                                                         writeln!(w, "use {}::{} as native{}Trait;", types.orig_crate, s, t).unwrap();
 858                                                                         for item in supertrait_obj.items.iter() {
 859                                                                                 match item {
 860                                                                                         syn::TraitItem::Method(m) => {
 861                                                                                                 impl_meth!(m, supertrait_obj, "\t");
 862                                                                                         },
 863                                                                                         _ => {},
 864                                                                                 }
 865                                                                         }
 866                                                                 }
 867                                                         }
 868                                                 ) );
 869                                                 write!(w, "\n").unwrap();
 870                                         } else if let Some(trait_ident) = trait_path.1.get_ident() {
 871                                                 //XXX: implement for other things like ToString
 872                                                 match &format!("{}", trait_ident) as &str {
 873                                                         "From" => {},
 874                                                         "Default" => {
 875                                                                 write!(w, "#[must_use]\n#[no_mangle]\npub extern \"C\" fn {}_default() -> {} {{\n", ident, ident).unwrap();
 876                                                                 write!(w, "\t{} {{ inner: Box::into_raw(Box::new(Default::default())), is_owned: true }}\n", ident).unwrap();
 877                                                                 write!(w, "}}\n").unwrap();
 878                                                         },
 879                                                         "PartialEq" => {},
 880                                                         // If we have no generics, try a manual implementation:
 881                                                         _ if p.path.get_ident().is_some() => maybe_convert_trait_impl(w, &trait_path.1, &*i.self_ty, types),
 882                                                         _ => {},
 883                                                 }
 884                                         } else if p.path.get_ident().is_some() {
 885                                                 // If we have no generics, try a manual implementation:
 886                                                 maybe_convert_trait_impl(w, &trait_path.1, &*i.self_ty, types);
 887                                         }
 888                                 } else {
 889                                         let declared_type = (*types.get_declared_type(&ident).unwrap()).clone();
 890                                         for item in i.items.iter() {
 891                                                 match item {
 892                                                         syn::ImplItem::Method(m) => {
 893                                                                 if let syn::Visibility::Public(_) = m.vis {
 894                                                                         match export_status(&m.attrs) {
 895                                                                                 ExportStatus::Export => {},
 896                                                                                 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
 897                                                                         }
 898                                                                         if m.defaultness.is_some() { unimplemented!(); }
 899                                                                         writeln_docs(w, &m.attrs, "");
 900                                                                         if let syn::ReturnType::Type(_, _) = &m.sig.output {
 901                                                                                 writeln!(w, "#[must_use]").unwrap();
 902                                                                         }
 903                                                                         write!(w, "#[no_mangle]\npub extern \"C\" fn {}_{}(", ident, m.sig.ident).unwrap();
 904                                                                         let ret_type = match &declared_type {
 905                                                                                 DeclType::MirroredEnum => format!("{}", ident),
 906                                                                                 DeclType::StructImported => format!("{}", ident),
 907                                                                                 _ => unimplemented!(),
 908                                                                         };
 909                                                                         gen_types.push_ctx();
 910                                                                         assert!(gen_types.learn_generics(&m.sig.generics, types));
 911                                                                         write_method_params(w, &m.sig, &ret_type, types, Some(&gen_types), false, true);
 912                                                                         write!(w, " {{\n\t").unwrap();
 913                                                                         write_method_var_decl_body(w, &m.sig, "", types, Some(&gen_types), false);
 914                                                                         let mut takes_self = false;
 915                                                                         let mut takes_mut_self = false;
 916                                                                         for inp in m.sig.inputs.iter() {
 917                                                                                 if let syn::FnArg::Receiver(r) = inp {
 918                                                                                         takes_self = true;
 919                                                                                         if r.mutability.is_some() { takes_mut_self = true; }
 920                                                                                 }
 921                                                                         }
 922                                                                         if takes_mut_self {
 923                                                                                 write!(w, "unsafe {{ &mut (*(this_arg.inner as *mut native{})) }}.{}(", ident, m.sig.ident).unwrap();
 924                                                                         } else if takes_self {
 925                                                                                 write!(w, "unsafe {{ &*this_arg.inner }}.{}(", m.sig.ident).unwrap();
 926                                                                         } else {
 927                                                                                 write!(w, "{}::{}::{}(", types.orig_crate, resolved_path, m.sig.ident).unwrap();
 928                                                                         }
 929                                                                         write_method_call_params(w, &m.sig, "", types, Some(&gen_types), &ret_type, false);
 930                                                                         gen_types.pop_ctx();
 931                                                                         writeln!(w, "\n}}\n").unwrap();
 932                                                                 }
 933                                                         },
 934                                                         _ => {},
 935                                                 }
 936                                         }
 937                                 }
 938                         } else {
 939                                 eprintln!("Not implementing anything for {} due to no-resolve (probably the type isn't pub or its marked not exported)", ident);
 940                         }
 941                 }
 942         }
 943 }
 944
 945 /// Returns true if the enum will be mapped as an opaue (ie struct with a pointer to the underlying
 946 /// type), otherwise it is mapped into a transparent, C-compatible version of itself.
 947 fn is_enum_opaque(e: &syn::ItemEnum) -> bool {
 948         for var in e.variants.iter() {
 949                 if let syn::Fields::Unit = var.fields {
 950                 } else if let syn::Fields::Named(fields) = &var.fields {
 951                         for field in fields.named.iter() {
 952                                 match export_status(&field.attrs) {
 953                                         ExportStatus::Export|ExportStatus::TestOnly => {},
 954                                         ExportStatus::NoExport => return true,
 955                                 }
 956                         }
 957                 } else {
 958                         return true;
 959                 }
 960         }
 961         false
 962 }
 963
 964 fn declare_enum<'a, 'b>(e: &'a syn::ItemEnum, types: &mut TypeResolver<'b, 'a>) {
 965         match export_status(&e.attrs) {
 966                 ExportStatus::Export => {},
 967                 ExportStatus::NoExport|ExportStatus::TestOnly => return,
 968         }
 969
 970         if is_enum_opaque(e) {
 971                 types.enum_ignored(&e.ident);
 972         } else {
 973                 types.mirrored_enum_declared(&e.ident);
 974         }
 975 }
 976
 977 /// Print a mapping of an enum. If all of the enum's fields are C-mapped in some form (or the enum
 978 /// is unitary), we generate an equivalent enum with all types replaced with their C mapped
 979 /// versions followed by conversion functions which map between the Rust version and the C mapped
 980 /// version.
 981 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) {
 982         match export_status(&e.attrs) {
 983                 ExportStatus::Export => {},
 984                 ExportStatus::NoExport|ExportStatus::TestOnly => return,
 985         }
 986
 987         if is_enum_opaque(e) {
 988                 eprintln!("Skipping enum {} as it contains non-unit fields", e.ident);
 989                 writeln_opaque(w, &e.ident, &format!("{}", e.ident), &e.generics, &e.attrs, types, extra_headers, cpp_headers);
 990                 return;
 991         }
 992         writeln_docs(w, &e.attrs, "");
 993
 994         if e.generics.lt_token.is_some() {
 995                 unimplemented!();
 996         }
 997
 998         let mut needs_free = false;
 999
1000         writeln!(w, "#[must_use]\n#[derive(Clone)]\n#[repr(C)]\npub enum {} {{", e.ident).unwrap();
1001         for var in e.variants.iter() {
1002                 assert_eq!(export_status(&var.attrs), ExportStatus::Export); // We can't partially-export a mirrored enum
1003                 writeln_docs(w, &var.attrs, "\t");
1004                 write!(w, "\t{}", var.ident).unwrap();
1005                 if let syn::Fields::Named(fields) = &var.fields {
1006                         needs_free = true;
1007                         writeln!(w, " {{").unwrap();
1008                         for field in fields.named.iter() {
1009                                 if export_status(&field.attrs) == ExportStatus::TestOnly { continue; }
1010                                 write!(w, "\t\t{}: ", field.ident.as_ref().unwrap()).unwrap();
1011                                 types.write_c_type(w, &field.ty, None, false);
1012                                 writeln!(w, ",").unwrap();
1013                         }
1014                         write!(w, "\t}}").unwrap();
1015                 }
1016                 if var.discriminant.is_some() { unimplemented!(); }
1017                 writeln!(w, ",").unwrap();
1018         }
1019         writeln!(w, "}}\nuse {}::{}::{} as native{};\nimpl {} {{", types.orig_crate, types.module_path, e.ident, e.ident, e.ident).unwrap();
1020
1021         macro_rules! write_conv {
1022                 ($fn_sig: expr, $to_c: expr, $ref: expr) => {
1023                         writeln!(w, "\t#[allow(unused)]\n\tpub(crate) fn {} {{\n\t\tmatch {} {{", $fn_sig, if $to_c { "native" } else { "self" }).unwrap();
1024                         for var in e.variants.iter() {
1025                                 write!(w, "\t\t\t{}{}::{} ", if $to_c { "native" } else { "" }, e.ident, var.ident).unwrap();
1026                                 if let syn::Fields::Named(fields) = &var.fields {
1027                                         write!(w, "{{").unwrap();
1028                                         for field in fields.named.iter() {
1029                                                 if export_status(&field.attrs) == ExportStatus::TestOnly { continue; }
1030                                                 write!(w, "{}{}, ", if $ref { "ref " } else { "mut " }, field.ident.as_ref().unwrap()).unwrap();
1031                                         }
1032                                         write!(w, "}} ").unwrap();
1033                                 }
1034                                 write!(w, "=>").unwrap();
1035                                 if let syn::Fields::Named(fields) = &var.fields {
1036                                         write!(w, " {{\n\t\t\t\t").unwrap();
1037                                         for field in fields.named.iter() {
1038                                                 if export_status(&field.attrs) == ExportStatus::TestOnly { continue; }
1039                                                 let mut sink = ::std::io::sink();
1040                                                 let mut out: &mut dyn std::io::Write = if $ref { &mut sink } else { w };
1041                                                 let new_var = if $to_c {
1042                                                         types.write_to_c_conversion_new_var(&mut out, field.ident.as_ref().unwrap(), &field.ty, None, false)
1043                                                 } else {
1044                                                         types.write_from_c_conversion_new_var(&mut out, field.ident.as_ref().unwrap(), &field.ty, None)
1045                                                 };
1046                                                 if $ref || new_var {
1047                                                         if $ref {
1048                                                                 write!(w, "let mut {}_nonref = (*{}).clone();\n\t\t\t\t", field.ident.as_ref().unwrap(), field.ident.as_ref().unwrap()).unwrap();
1049                                                                 if new_var {
1050                                                                         let nonref_ident = syn::Ident::new(&format!("{}_nonref", field.ident.as_ref().unwrap()), Span::call_site());
1051                                                                         if $to_c {
1052                                                                                 types.write_to_c_conversion_new_var(w, &nonref_ident, &field.ty, None, false);
1053                                                                         } else {
1054                                                                                 types.write_from_c_conversion_new_var(w, &nonref_ident, &field.ty, None);
1055                                                                         }
1056                                                                         write!(w, "\n\t\t\t\t").unwrap();
1057                                                                 }
1058                                                         } else {
1059                                                                 write!(w, "\n\t\t\t\t").unwrap();
1060                                                         }
1061                                                 }
1062                                         }
1063                                 } else { write!(w, " ").unwrap(); }
1064                                 write!(w, "{}{}::{}", if $to_c { "" } else { "native" }, e.ident, var.ident).unwrap();
1065                                 if let syn::Fields::Named(fields) = &var.fields {
1066                                         write!(w, " {{").unwrap();
1067                                         for field in fields.named.iter() {
1068                                                 if export_status(&field.attrs) == ExportStatus::TestOnly { continue; }
1069                                                 write!(w, "\n\t\t\t\t\t{}: ", field.ident.as_ref().unwrap()).unwrap();
1070                                                 if $to_c {
1071                                                         types.write_to_c_conversion_inline_prefix(w, &field.ty, None, false);
1072                                                 } else {
1073                                                         types.write_from_c_conversion_prefix(w, &field.ty, None);
1074                                                 }
1075                                                 write!(w, "{}{}",
1076                                                         field.ident.as_ref().unwrap(),
1077                                                         if $ref { "_nonref" } else { "" }).unwrap();
1078                                                 if $to_c {
1079                                                         types.write_to_c_conversion_inline_suffix(w, &field.ty, None, false);
1080                                                 } else {
1081                                                         types.write_from_c_conversion_suffix(w, &field.ty, None);
1082                                                 }
1083                                                 write!(w, ",").unwrap();
1084                                         }
1085                                         writeln!(w, "\n\t\t\t\t}}").unwrap();
1086                                         write!(w, "\t\t\t}}").unwrap();
1087                                 }
1088                                 writeln!(w, ",").unwrap();
1089                         }
1090                         writeln!(w, "\t\t}}\n\t}}").unwrap();
1091                 }
1092         }
1093
1094         write_conv!(format!("to_native(&self) -> native{}", e.ident), false, true);
1095         write_conv!(format!("into_native(self) -> native{}", e.ident), false, false);
1096         write_conv!(format!("from_native(native: &native{}) -> Self", e.ident), true, true);
1097         write_conv!(format!("native_into(native: native{}) -> Self", e.ident), true, false);
1098         writeln!(w, "}}").unwrap();
1099
1100         if needs_free {
1101                 writeln!(w, "#[no_mangle]\npub extern \"C\" fn {}_free(this_ptr: {}) {{ }}", e.ident, e.ident).unwrap();
1102         }
1103         writeln!(w, "#[no_mangle]").unwrap();
1104         writeln!(w, "pub extern \"C\" fn {}_clone(orig: &{}) -> {} {{", e.ident, e.ident, e.ident).unwrap();
1105         writeln!(w, "\torig.clone()").unwrap();
1106         writeln!(w, "}}").unwrap();
1107         write_cpp_wrapper(cpp_headers, &format!("{}", e.ident), needs_free);
1108 }
1109
1110 fn writeln_fn<'a, 'b, W: std::io::Write>(w: &mut W, f: &'a syn::ItemFn, types: &mut TypeResolver<'b, 'a>) {
1111         match export_status(&f.attrs) {
1112                 ExportStatus::Export => {},
1113                 ExportStatus::NoExport|ExportStatus::TestOnly => return,
1114         }
1115         writeln_docs(w, &f.attrs, "");
1116
1117         let mut gen_types = GenericTypes::new();
1118         if !gen_types.learn_generics(&f.sig.generics, types) { return; }
1119
1120         write!(w, "#[no_mangle]\npub extern \"C\" fn {}(", f.sig.ident).unwrap();
1121         write_method_params(w, &f.sig, "", types, Some(&gen_types), false, true);
1122         write!(w, " {{\n\t").unwrap();
1123         write_method_var_decl_body(w, &f.sig, "", types, Some(&gen_types), false);
1124         write!(w, "{}::{}::{}(", types.orig_crate, types.module_path, f.sig.ident).unwrap();
1125         write_method_call_params(w, &f.sig, "", types, Some(&gen_types), "", false);
1126         writeln!(w, "\n}}\n").unwrap();
1127 }
1128
1129 // ********************************
1130 // *** File/Crate Walking Logic ***
1131 // ********************************
1132
1133 /// Simple utility to walk the modules in a crate - iterating over the modules (with file paths) in
1134 /// a single File.
1135 struct FileIter<'a, I: Iterator<Item = &'a syn::Item>> {
1136         in_dir: &'a str,
1137         path: &'a str,
1138         module: &'a str,
1139         item_iter: I,
1140 }
1141 impl<'a, I: Iterator<Item = &'a syn::Item>> Iterator for FileIter<'a, I> {
1142         type Item = (String, String, &'a syn::ItemMod);
1143         fn next(&mut self) -> std::option::Option<<Self as std::iter::Iterator>::Item> {
1144                 loop {
1145                         match self.item_iter.next() {
1146                                 Some(syn::Item::Mod(m)) => {
1147                                         if let syn::Visibility::Public(_) = m.vis {
1148                                                 match export_status(&m.attrs) {
1149                                                         ExportStatus::Export => {},
1150                                                         ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1151                                                 }
1152
1153                                                 let f_path = format!("{}/{}.rs", (self.path.as_ref() as &Path).parent().unwrap().display(), m.ident);
1154                                                 let new_mod = if self.module.is_empty() { format!("{}", m.ident) } else { format!("{}::{}", self.module, m.ident) };
1155                                                 if let Ok(_) = File::open(&format!("{}/{}", self.in_dir, f_path)) {
1156                                                         return Some((f_path, new_mod, m));
1157                                                 } else {
1158                                                         return Some((
1159                                                                 format!("{}/{}/mod.rs", (self.path.as_ref() as &Path).parent().unwrap().display(), m.ident),
1160                                                                 new_mod, m));
1161                                                 }
1162                                         }
1163                                 },
1164                                 Some(_) => {},
1165                                 None => return None,
1166                         }
1167                 }
1168         }
1169 }
1170 fn file_iter<'a>(file: &'a syn::File, in_dir: &'a str, path: &'a str, module: &'a str) ->
1171                 impl Iterator<Item = (String, String, &'a syn::ItemMod)> + 'a {
1172         FileIter { in_dir, path, module, item_iter: file.items.iter() }
1173 }
1174
1175 /// A struct containing the syn::File AST for each file in the crate.
1176 struct FullLibraryAST {
1177         files: HashMap<String, syn::File>,
1178 }
1179
1180 /// Do the Real Work of mapping an original file to C-callable wrappers. Creates a new file at
1181 /// `out_path` and fills it with wrapper structs/functions to allow calling the things in the AST
1182 /// at `module` from C.
1183 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) {
1184         let syntax = if let Some(ast) = libast.files.get(module) { ast } else { return };
1185
1186         assert!(syntax.shebang.is_none()); // Not sure what this is, hope we dont have one
1187
1188         let new_file_path = format!("{}/{}", out_dir, path);
1189         let _ = std::fs::create_dir((&new_file_path.as_ref() as &std::path::Path).parent().unwrap());
1190         let mut out = std::fs::OpenOptions::new().write(true).create(true).truncate(true)
1191                 .open(new_file_path).expect("Unable to open new src file");
1192
1193         assert_eq!(export_status(&syntax.attrs), ExportStatus::Export);
1194         writeln_docs(&mut out, &syntax.attrs, "");
1195
1196         if path.ends_with("/lib.rs") {
1197                 // Special-case the top-level lib.rs with various lint allows and a pointer to the c_types
1198                 // and bitcoin hand-written modules.
1199                 writeln!(out, "#![allow(unknown_lints)]").unwrap();
1200                 writeln!(out, "#![allow(non_camel_case_types)]").unwrap();
1201                 writeln!(out, "#![allow(non_snake_case)]").unwrap();
1202                 writeln!(out, "#![allow(unused_imports)]").unwrap();
1203                 writeln!(out, "#![allow(unused_variables)]").unwrap();
1204                 writeln!(out, "#![allow(unused_mut)]").unwrap();
1205                 writeln!(out, "#![allow(unused_parens)]").unwrap();
1206                 writeln!(out, "#![allow(unused_unsafe)]").unwrap();
1207                 writeln!(out, "#![allow(unused_braces)]").unwrap();
1208                 writeln!(out, "mod c_types;").unwrap();
1209                 writeln!(out, "mod bitcoin;").unwrap();
1210         } else {
1211                 writeln!(out, "\nuse std::ffi::c_void;\nuse bitcoin::hashes::Hash;\nuse crate::c_types::*;\n").unwrap();
1212         }
1213
1214         for (path, new_mod, m) in file_iter(&syntax, in_dir, path, &module) {
1215                 writeln_docs(&mut out, &m.attrs, "");
1216                 writeln!(out, "pub mod {};", m.ident).unwrap();
1217                 convert_file(libast, crate_types, in_dir, out_dir, &path,
1218                         orig_crate, &new_mod, header_file, cpp_header_file);
1219         }
1220
1221         eprintln!("Converting {} entries...", path);
1222
1223         let mut type_resolver = TypeResolver::new(orig_crate, module, crate_types);
1224
1225         // First pass over the items and fill in imports and file-declared objects in the type resolver
1226         for item in syntax.items.iter() {
1227                 match item {
1228                         syn::Item::Use(u) => type_resolver.process_use(&mut out, &u),
1229                         syn::Item::Struct(s) => {
1230                                 if let syn::Visibility::Public(_) = s.vis {
1231                                         declare_struct(&s, &mut type_resolver);
1232                                 }
1233                         },
1234                         syn::Item::Enum(e) => {
1235                                 if let syn::Visibility::Public(_) = e.vis {
1236                                         declare_enum(&e, &mut type_resolver);
1237                                 }
1238                         },
1239                         _ => {},
1240                 }
1241         }
1242
1243         for item in syntax.items.iter() {
1244                 match item {
1245                         syn::Item::Use(_) => {}, // Handled above
1246                         syn::Item::Static(_) => {},
1247                         syn::Item::Enum(e) => {
1248                                 if let syn::Visibility::Public(_) = e.vis {
1249                                         writeln_enum(&mut out, &e, &mut type_resolver, header_file, cpp_header_file);
1250                                 }
1251                         },
1252                         syn::Item::Impl(i) => {
1253                                 writeln_impl(&mut out, &i, &mut type_resolver);
1254                         },
1255                         syn::Item::Struct(s) => {
1256                                 if let syn::Visibility::Public(_) = s.vis {
1257                                         writeln_struct(&mut out, &s, &mut type_resolver, header_file, cpp_header_file);
1258                                 }
1259                         },
1260                         syn::Item::Trait(t) => {
1261                                 if let syn::Visibility::Public(_) = t.vis {
1262                                         writeln_trait(&mut out, &t, &mut type_resolver, header_file, cpp_header_file);
1263                                 }
1264                         },
1265                         syn::Item::Mod(_) => {}, // We don't have to do anything - the top loop handles these.
1266                         syn::Item::Const(c) => {
1267                                 // Re-export any primitive-type constants.
1268                                 if let syn::Visibility::Public(_) = c.vis {
1269                                         if let syn::Type::Path(p) = &*c.ty {
1270                                                 let resolved_path = type_resolver.resolve_path(&p.path, None);
1271                                                 if type_resolver.is_primitive(&resolved_path) {
1272                                                         writeln!(out, "\n#[no_mangle]").unwrap();
1273                                                         writeln!(out, "pub static {}: {} = {}::{}::{};", c.ident, resolved_path, orig_crate, module, c.ident).unwrap();
1274                                                 }
1275                                         }
1276                                 }
1277                         },
1278                         syn::Item::Type(t) => {
1279                                 if let syn::Visibility::Public(_) = t.vis {
1280                                         match export_status(&t.attrs) {
1281                                                 ExportStatus::Export => {},
1282                                                 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1283                                         }
1284
1285                                         let mut process_alias = true;
1286                                         for tok in t.generics.params.iter() {
1287                                                 if let syn::GenericParam::Lifetime(_) = tok {}
1288                                                 else { process_alias = false; }
1289                                         }
1290                                         if process_alias {
1291                                                 match &*t.ty {
1292                                                         syn::Type::Path(_) =>
1293                                                                 writeln_opaque(&mut out, &t.ident, &format!("{}", t.ident), &t.generics, &t.attrs, &type_resolver, header_file, cpp_header_file),
1294                                                         _ => {}
1295                                                 }
1296                                         }
1297                                 }
1298                         },
1299                         syn::Item::Fn(f) => {
1300                                 if let syn::Visibility::Public(_) = f.vis {
1301                                         writeln_fn(&mut out, &f, &mut type_resolver);
1302                                 }
1303                         },
1304                         syn::Item::Macro(m) => {
1305                                 if m.ident.is_none() { // If its not a macro definition
1306                                         convert_macro(&mut out, &m.mac.path, &m.mac.tokens, &type_resolver);
1307                                 }
1308                         },
1309                         syn::Item::Verbatim(_) => {},
1310                         syn::Item::ExternCrate(_) => {},
1311                         _ => unimplemented!(),
1312                 }
1313         }
1314
1315         out.flush().unwrap();
1316 }
1317
1318 /// Load the AST for each file in the crate, filling the FullLibraryAST object
1319 fn load_ast(in_dir: &str, path: &str, module: String, ast_storage: &mut FullLibraryAST) {
1320         eprintln!("Loading {}{}...", in_dir, path);
1321
1322         let mut file = File::open(format!("{}/{}", in_dir, path)).expect("Unable to open file");
1323         let mut src = String::new();
1324         file.read_to_string(&mut src).expect("Unable to read file");
1325         let syntax = syn::parse_file(&src).expect("Unable to parse file");
1326
1327         assert_eq!(export_status(&syntax.attrs), ExportStatus::Export);
1328
1329         for (path, new_mod, _) in file_iter(&syntax, in_dir, path, &module) {
1330                 load_ast(in_dir, &path, new_mod, ast_storage);
1331         }
1332         ast_storage.files.insert(module, syntax);
1333 }
1334
1335 /// Insert ident -> absolute Path resolutions into imports from the given UseTree and path-prefix.
1336 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>) {
1337         match u {
1338                 syn::UseTree::Path(p) => {
1339                         path.push(syn::PathSegment { ident: p.ident.clone(), arguments: syn::PathArguments::None });
1340                         process_use_intern(&p.tree, path, imports);
1341                 },
1342                 syn::UseTree::Name(n) => {
1343                         path.push(syn::PathSegment { ident: n.ident.clone(), arguments: syn::PathArguments::None });
1344                         imports.insert(&n.ident, syn::Path { leading_colon: Some(syn::Token![::](Span::call_site())), segments: path });
1345                 },
1346                 syn::UseTree::Group(g) => {
1347                         for i in g.items.iter() {
1348                                 process_use_intern(i, path.clone(), imports);
1349                         }
1350                 },
1351                 _ => {}
1352         }
1353 }
1354
1355 /// Map all the Paths in a Type into absolute paths given a set of imports (generated via process_use_intern)
1356 fn resolve_imported_refs(imports: &HashMap<&syn::Ident, syn::Path>, mut ty: syn::Type) -> syn::Type {
1357         match &mut ty {
1358                 syn::Type::Path(p) => {
1359                         if let Some(ident) = p.path.get_ident() {
1360                                 if let Some(newpath) = imports.get(ident) {
1361                                         p.path = newpath.clone();
1362                                 }
1363                         } else { unimplemented!(); }
1364                 },
1365                 syn::Type::Reference(r) => {
1366                         r.elem = Box::new(resolve_imported_refs(imports, (*r.elem).clone()));
1367                 },
1368                 syn::Type::Slice(s) => {
1369                         s.elem = Box::new(resolve_imported_refs(imports, (*s.elem).clone()));
1370                 },
1371                 syn::Type::Tuple(t) => {
1372                         for e in t.elems.iter_mut() {
1373                                 *e = resolve_imported_refs(imports, e.clone());
1374                         }
1375                 },
1376                 _ => unimplemented!(),
1377         }
1378         ty
1379 }
1380
1381 /// Walk the FullLibraryAST, deciding how things will be mapped and adding tracking to CrateTypes.
1382 fn walk_ast<'a>(in_dir: &str, path: &str, module: String, ast_storage: &'a FullLibraryAST, crate_types: &mut CrateTypes<'a>) {
1383         let syntax = if let Some(ast) = ast_storage.files.get(&module) { ast } else { return };
1384         assert_eq!(export_status(&syntax.attrs), ExportStatus::Export);
1385
1386         for (path, new_mod, _) in file_iter(&syntax, in_dir, path, &module) {
1387                 walk_ast(in_dir, &path, new_mod, ast_storage, crate_types);
1388         }
1389
1390         let mut import_maps = HashMap::new();
1391
1392         for item in syntax.items.iter() {
1393                 match item {
1394                         syn::Item::Use(u) => {
1395                                 process_use_intern(&u.tree, syn::punctuated::Punctuated::new(), &mut import_maps);
1396                         },
1397                         syn::Item::Struct(s) => {
1398                                 if let syn::Visibility::Public(_) = s.vis {
1399                                         match export_status(&s.attrs) {
1400                                                 ExportStatus::Export => {},
1401                                                 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1402                                         }
1403                                         let struct_path = format!("{}::{}", module, s.ident);
1404                                         crate_types.opaques.insert(struct_path, &s.ident);
1405                                 }
1406                         },
1407                         syn::Item::Trait(t) => {
1408                                 if let syn::Visibility::Public(_) = t.vis {
1409                                         match export_status(&t.attrs) {
1410                                                 ExportStatus::Export => {},
1411                                                 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1412                                         }
1413                                         let trait_path = format!("{}::{}", module, t.ident);
1414                                         crate_types.traits.insert(trait_path, &t);
1415                                 }
1416                         },
1417                         syn::Item::Type(t) => {
1418                                 if let syn::Visibility::Public(_) = t.vis {
1419                                         match export_status(&t.attrs) {
1420                                                 ExportStatus::Export => {},
1421                                                 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1422                                         }
1423                                         let type_path = format!("{}::{}", module, t.ident);
1424                                         let mut process_alias = true;
1425                                         for tok in t.generics.params.iter() {
1426                                                 if let syn::GenericParam::Lifetime(_) = tok {}
1427                                                 else { process_alias = false; }
1428                                         }
1429                                         if process_alias {
1430                                                 match &*t.ty {
1431                                                         syn::Type::Path(_) => {
1432                                                                 // If its a path with no generics, assume we don't map the aliased type and map it opaque
1433                                                                 crate_types.opaques.insert(type_path, &t.ident);
1434                                                         },
1435                                                         _ => {
1436                                                                 crate_types.type_aliases.insert(type_path, resolve_imported_refs(&import_maps, (*t.ty).clone()));
1437                                                         }
1438                                                 }
1439                                         }
1440                                 }
1441                         },
1442                         syn::Item::Enum(e) if is_enum_opaque(e) => {
1443                                 if let syn::Visibility::Public(_) = e.vis {
1444                                         match export_status(&e.attrs) {
1445                                                 ExportStatus::Export => {},
1446                                                 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1447                                         }
1448                                         let enum_path = format!("{}::{}", module, e.ident);
1449                                         crate_types.opaques.insert(enum_path, &e.ident);
1450                                 }
1451                         },
1452                         syn::Item::Enum(e) => {
1453                                 if let syn::Visibility::Public(_) = e.vis {
1454                                         match export_status(&e.attrs) {
1455                                                 ExportStatus::Export => {},
1456                                                 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1457                                         }
1458                                         let enum_path = format!("{}::{}", module, e.ident);
1459                                         crate_types.mirrored_enums.insert(enum_path, &e);
1460                                 }
1461                         },
1462                         _ => {},
1463                 }
1464         }
1465 }
1466
1467 fn main() {
1468         let args: Vec<String> = env::args().collect();
1469         if args.len() != 7 {
1470                 eprintln!("Usage: source/dir target/dir source_crate_name derived_templates.rs extra/includes.h extra/cpp/includes.hpp");
1471                 process::exit(1);
1472         }
1473
1474         let mut derived_templates = std::fs::OpenOptions::new().write(true).create(true).truncate(true)
1475                 .open(&args[4]).expect("Unable to open new header file");
1476         let mut header_file = std::fs::OpenOptions::new().write(true).create(true).truncate(true)
1477                 .open(&args[5]).expect("Unable to open new header file");
1478         let mut cpp_header_file = std::fs::OpenOptions::new().write(true).create(true).truncate(true)
1479                 .open(&args[6]).expect("Unable to open new header file");
1480
1481         writeln!(header_file, "#if defined(__GNUC__)\n#define MUST_USE_STRUCT __attribute__((warn_unused))").unwrap();
1482         writeln!(header_file, "#else\n#define MUST_USE_STRUCT\n#endif").unwrap();
1483         writeln!(header_file, "#if defined(__GNUC__)\n#define MUST_USE_RES __attribute__((warn_unused_result))").unwrap();
1484         writeln!(header_file, "#else\n#define MUST_USE_RES\n#endif").unwrap();
1485         writeln!(cpp_header_file, "#include <string.h>\nnamespace LDK {{").unwrap();
1486
1487         // First parse the full crate's ASTs, caching them so that we can hold references to the AST
1488         // objects in other datastructures:
1489         let mut libast = FullLibraryAST { files: HashMap::new() };
1490         load_ast(&args[1], "/lib.rs", "".to_string(), &mut libast);
1491
1492         // ...then walk the ASTs tracking what types we will map, and how, so that we can resolve them
1493         // when parsing other file ASTs...
1494         let mut libtypes = CrateTypes { traits: HashMap::new(), opaques: HashMap::new(), mirrored_enums: HashMap::new(),
1495                 type_aliases: HashMap::new(), templates_defined: HashMap::default(), template_file: &mut derived_templates };
1496         walk_ast(&args[1], "/lib.rs", "".to_string(), &libast, &mut libtypes);
1497
1498         // ... finally, do the actual file conversion/mapping, writing out types as we go.
1499         convert_file(&libast, &mut libtypes, &args[1], &args[2], "/lib.rs", &args[3], "", &mut header_file, &mut cpp_header_file);
1500
1501         // For container templates which we created while walking the crate, make sure we add C++
1502         // mapped types so that C++ users can utilize the auto-destructors available.
1503         for (ty, has_destructor) in libtypes.templates_defined.iter() {
1504                 write_cpp_wrapper(&mut cpp_header_file, ty, *has_destructor);
1505         }
1506         writeln!(cpp_header_file, "}}").unwrap();
1507
1508         header_file.flush().unwrap();
1509         cpp_header_file.flush().unwrap();
1510         derived_templates.flush().unwrap();
1511 }