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