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

   1 // This file is Copyright its original authors, visible in version control
   2 // history.
   3 //
   4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE>
   5 // or the MIT license <LICENSE-MIT>, at your option.
   6 // You may not use this file except in accordance with one or both of these
   7 // licenses.
   8
   9 //! Converts a rust crate into a rust crate containing a number of C-exported wrapper functions and
  10 //! classes (which is exportable using cbindgen).
  11 //! In general, supports convering:
  12 //!  * structs as a pointer to the underlying type (either owned or not owned),
  13 //!  * traits as a void-ptr plus a jump table,
  14 //!  * enums as an equivalent enum with all the inner fields mapped to the mapped types,
  15 //!  * certain containers (tuples, slices, Vecs, Options, and Results currently) to a concrete
  16 //!    version of a defined container template.
  17 //!
  18 //! It also generates relevant memory-management functions and free-standing functions with
  19 //! parameters mapped.
  20
  21 use std::collections::{HashMap, hash_map};
  22 use std::env;
  23 use std::fs::File;
  24 use std::io::{Read, Write};
  25 use std::process;
  26
  27 use proc_macro2::Span;
  28 use quote::format_ident;
  29 use syn::parse_quote;
  30
  31 mod types;
  32 mod blocks;
  33 use types::*;
  34 use blocks::*;
  35
  36 const DEFAULT_IMPORTS: &'static str = "\nuse std::str::FromStr;\nuse std::ffi::c_void;\nuse bitcoin::hashes::Hash;\nuse crate::c_types::*;\n";
  37
  38 // *************************************
  39 // *** Manually-expanded conversions ***
  40 // *************************************
  41
  42 /// Convert "impl trait_path for for_ty { .. }" for manually-mapped types (ie (de)serialization)
  43 fn maybe_convert_trait_impl<W: std::io::Write>(w: &mut W, trait_path: &syn::Path, for_ty: &syn::Type, types: &mut TypeResolver, generics: &GenericTypes) {
  44         if let Some(t) = types.maybe_resolve_path(&trait_path, Some(generics)) {
  45                 let for_obj;
  46                 let full_obj_path;
  47                 let mut has_inner = false;
  48                 if let syn::Type::Path(ref p) = for_ty {
  49                         if let Some(ident) = single_ident_generic_path_to_ident(&p.path) {
  50                                 for_obj = format!("{}", ident);
  51                                 full_obj_path = for_obj.clone();
  52                                 has_inner = types.c_type_has_inner_from_path(&types.resolve_path(&p.path, Some(generics)));
  53                         } else { return; }
  54                 } else {
  55                         // We assume that anything that isn't a Path is somehow a generic that ends up in our
  56                         // derived-types module.
  57                         let mut for_obj_vec = Vec::new();
  58                         types.write_c_type(&mut for_obj_vec, for_ty, Some(generics), false);
  59                         full_obj_path = String::from_utf8(for_obj_vec).unwrap();
  60                         assert!(full_obj_path.starts_with(TypeResolver::generated_container_path()));
  61                         for_obj = full_obj_path[TypeResolver::generated_container_path().len() + 2..].into();
  62                 }
  63
  64                 match &t as &str {
  65                         "lightning::util::ser::Writeable" => {
  66                                 writeln!(w, "#[no_mangle]").unwrap();
  67                                 writeln!(w, "/// Serialize the {} object into a byte array which can be read by {}_read", for_obj, for_obj).unwrap();
  68                                 writeln!(w, "pub extern \"C\" fn {}_write(obj: &{}) -> crate::c_types::derived::CVec_u8Z {{", for_obj, full_obj_path).unwrap();
  69
  70                                 let ref_type: syn::Type = syn::parse_quote!(&#for_ty);
  71                                 assert!(!types.write_from_c_conversion_new_var(w, &format_ident!("obj"), &ref_type, Some(generics)));
  72
  73                                 write!(w, "\tcrate::c_types::serialize_obj(").unwrap();
  74                                 types.write_from_c_conversion_prefix(w, &ref_type, Some(generics));
  75                                 write!(w, "unsafe {{ &*obj }}").unwrap();
  76                                 types.write_from_c_conversion_suffix(w, &ref_type, Some(generics));
  77                                 writeln!(w, ")").unwrap();
  78
  79                                 writeln!(w, "}}").unwrap();
  80                                 if has_inner {
  81                                         writeln!(w, "#[no_mangle]").unwrap();
  82                                         writeln!(w, "pub(crate) extern \"C\" fn {}_write_void(obj: *const c_void) -> crate::c_types::derived::CVec_u8Z {{", for_obj).unwrap();
  83                                         writeln!(w, "\tcrate::c_types::serialize_obj(unsafe {{ &*(obj as *const native{}) }})", for_obj).unwrap();
  84                                         writeln!(w, "}}").unwrap();
  85                                 }
  86                         },
  87                         "lightning::util::ser::Readable"|"lightning::util::ser::ReadableArgs" => {
  88                                 // Create the Result<Object, DecodeError> syn::Type
  89                                 let res_ty: syn::Type = parse_quote!(Result<#for_ty, ::ln::msgs::DecodeError>);
  90
  91                                 writeln!(w, "#[no_mangle]").unwrap();
  92                                 writeln!(w, "/// Read a {} from a byte array, created by {}_write", for_obj, for_obj).unwrap();
  93                                 write!(w, "pub extern \"C\" fn {}_read(ser: crate::c_types::u8slice", for_obj).unwrap();
  94
  95                                 let mut arg_conv = Vec::new();
  96                                 if t == "lightning::util::ser::ReadableArgs" {
  97                                         write!(w, ", arg: ").unwrap();
  98                                         assert!(trait_path.leading_colon.is_none());
  99                                         let args_seg = trait_path.segments.iter().last().unwrap();
 100                                         assert_eq!(format!("{}", args_seg.ident), "ReadableArgs");
 101                                         if let syn::PathArguments::AngleBracketed(args) = &args_seg.arguments {
 102                                                 assert_eq!(args.args.len(), 1);
 103                                                 if let syn::GenericArgument::Type(args_ty) = args.args.iter().next().unwrap() {
 104                                                         types.write_c_type(w, args_ty, Some(generics), false);
 105
 106                                                         assert!(!types.write_from_c_conversion_new_var(&mut arg_conv, &format_ident!("arg"), &args_ty, Some(generics)));
 107
 108                                                         write!(&mut arg_conv, "\tlet arg_conv = ").unwrap();
 109                                                         types.write_from_c_conversion_prefix(&mut arg_conv, &args_ty, Some(generics));
 110                                                         write!(&mut arg_conv, "arg").unwrap();
 111                                                         types.write_from_c_conversion_suffix(&mut arg_conv, &args_ty, Some(generics));
 112                                                 } else { unreachable!(); }
 113                                         } else { unreachable!(); }
 114                                 }
 115                                 write!(w, ") -> ").unwrap();
 116                                 types.write_c_type(w, &res_ty, Some(generics), false);
 117                                 writeln!(w, " {{").unwrap();
 118
 119                                 if t == "lightning::util::ser::ReadableArgs" {
 120                                         w.write(&arg_conv).unwrap();
 121                                         write!(w, ";\n\tlet res: ").unwrap();
 122                                         // At least in one case we need type annotations here, so provide them.
 123                                         types.write_rust_type(w, Some(generics), &res_ty);
 124                                         writeln!(w, " = crate::c_types::deserialize_obj_arg(ser, arg_conv);").unwrap();
 125                                 } else {
 126                                         writeln!(w, "\tlet res = crate::c_types::deserialize_obj(ser);").unwrap();
 127                                 }
 128                                 write!(w, "\t").unwrap();
 129                                 if types.write_to_c_conversion_new_var(w, &format_ident!("res"), &res_ty, Some(generics), false) {
 130                                         write!(w, "\n\t").unwrap();
 131                                 }
 132                                 types.write_to_c_conversion_inline_prefix(w, &res_ty, Some(generics), false);
 133                                 write!(w, "res").unwrap();
 134                                 types.write_to_c_conversion_inline_suffix(w, &res_ty, Some(generics), false);
 135                                 writeln!(w, "\n}}").unwrap();
 136                         },
 137                         _ => {},
 138                 }
 139         }
 140 }
 141
 142 /// Convert "TraitA : TraitB" to a single function name and return type.
 143 ///
 144 /// This is (obviously) somewhat over-specialized and only useful for TraitB's that only require a
 145 /// single function (eg for serialization).
 146 fn convert_trait_impl_field(trait_path: &str) -> (&'static str, String, &'static str) {
 147         match trait_path {
 148                 "lightning::util::ser::Writeable" => ("Serialize the object into a byte array", "write".to_owned(), "crate::c_types::derived::CVec_u8Z"),
 149                 _ => unimplemented!(),
 150         }
 151 }
 152
 153 /// Companion to convert_trait_impl_field, write an assignment for the function defined by it for
 154 /// `for_obj` which implements the the trait at `trait_path`.
 155 fn write_trait_impl_field_assign<W: std::io::Write>(w: &mut W, trait_path: &str, for_obj: &syn::Ident) {
 156         match trait_path {
 157                 "lightning::util::ser::Writeable" => {
 158                         writeln!(w, "\t\twrite: {}_write_void,", for_obj).unwrap();
 159                 },
 160                 _ => unimplemented!(),
 161         }
 162 }
 163
 164 /// Write out the impl block for a defined trait struct which has a supertrait
 165 fn do_write_impl_trait<W: std::io::Write>(w: &mut W, trait_path: &str, _trait_name: &syn::Ident, for_obj: &str) {
 166         match trait_path {
 167                 "lightning::util::ser::Writeable" => {
 168                         writeln!(w, "impl {} for {} {{", trait_path, for_obj).unwrap();
 169                         writeln!(w, "\tfn write<W: lightning::util::ser::Writer>(&self, w: &mut W) -> Result<(), ::std::io::Error> {{").unwrap();
 170                         writeln!(w, "\t\tlet vec = (self.write)(self.this_arg);").unwrap();
 171                         writeln!(w, "\t\tw.write_all(vec.as_slice())").unwrap();
 172                         writeln!(w, "\t}}\n}}").unwrap();
 173                 },
 174                 _ => panic!(),
 175         }
 176 }
 177
 178 // *******************************
 179 // *** Per-Type Printing Logic ***
 180 // *******************************
 181
 182 macro_rules! walk_supertraits { ($t: expr, $types: expr, ($( $($pat: pat)|* => $e: expr),*) ) => { {
 183         if $t.colon_token.is_some() {
 184                 for st in $t.supertraits.iter() {
 185                         match st {
 186                                 syn::TypeParamBound::Trait(supertrait) => {
 187                                         if supertrait.paren_token.is_some() || supertrait.lifetimes.is_some() {
 188                                                 unimplemented!();
 189                                         }
 190                                         // First try to resolve path to find in-crate traits, but if that doesn't work
 191                                         // assume its a prelude trait (eg Clone, etc) and just use the single ident.
 192                                         let types_opt: Option<&TypeResolver> = $types;
 193                                         if let Some(types) = types_opt {
 194                                                 if let Some(path) = types.maybe_resolve_path(&supertrait.path, None) {
 195                                                         match (&path as &str, &supertrait.path.segments.iter().last().unwrap().ident) {
 196                                                                 $( $($pat)|* => $e, )*
 197                                                         }
 198                                                         continue;
 199                                                 }
 200                                         }
 201                                         if let Some(ident) = supertrait.path.get_ident() {
 202                                                 match (&format!("{}", ident) as &str, &ident) {
 203                                                         $( $($pat)|* => $e, )*
 204                                                 }
 205                                         } else if types_opt.is_some() {
 206                                                 panic!("Supertrait unresolvable and not single-ident");
 207                                         }
 208                                 },
 209                                 syn::TypeParamBound::Lifetime(_) => unimplemented!(),
 210                         }
 211                 }
 212         }
 213 } } }
 214
 215 /// Prints a C-mapped trait object containing a void pointer and a jump table for each function in
 216 /// the original trait.
 217 /// Implements the native Rust trait and relevant parent traits for the new C-mapped trait.
 218 ///
 219 /// Finally, implements Deref<MappedTrait> for MappedTrait which allows its use in types which need
 220 /// a concrete Deref to the Rust trait.
 221 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) {
 222         let trait_name = format!("{}", t.ident);
 223         let implementable;
 224         match export_status(&t.attrs) {
 225                 ExportStatus::Export => { implementable = true; }
 226                 ExportStatus::NotImplementable => { implementable = false; },
 227                 ExportStatus::NoExport|ExportStatus::TestOnly => return,
 228         }
 229         writeln_docs(w, &t.attrs, "");
 230
 231         let mut gen_types = GenericTypes::new(None);
 232         assert!(gen_types.learn_generics(&t.generics, types));
 233         gen_types.learn_associated_types(&t, types);
 234
 235         writeln!(w, "#[repr(C)]\npub struct {} {{", trait_name).unwrap();
 236         writeln!(w, "\t/// An opaque pointer which is passed to your function implementations as an argument.").unwrap();
 237         writeln!(w, "\t/// This has no meaning in the LDK, and can be NULL or any other value.").unwrap();
 238         writeln!(w, "\tpub this_arg: *mut c_void,").unwrap();
 239         // We store every field's (name, Option<clone_fn>, docs) except this_arg, used in Clone generation
 240         // docs is only set if its a function which should be callable on the object itself in C++
 241         let mut generated_fields = Vec::new();
 242         for item in t.items.iter() {
 243                 match item {
 244                         &syn::TraitItem::Method(ref m) => {
 245                                 match export_status(&m.attrs) {
 246                                         ExportStatus::NoExport => {
 247                                                 // NoExport in this context means we'll hit an unimplemented!() at runtime,
 248                                                 // so bail out.
 249                                                 unimplemented!();
 250                                         },
 251                                         ExportStatus::Export => {},
 252                                         ExportStatus::TestOnly => continue,
 253                                         ExportStatus::NotImplementable => panic!("(C-not implementable) must only appear on traits"),
 254                                 }
 255                                 if m.default.is_some() { unimplemented!(); }
 256
 257                                 let mut meth_gen_types = gen_types.push_ctx();
 258                                 assert!(meth_gen_types.learn_generics(&m.sig.generics, types));
 259
 260                                 writeln_fn_docs(w, &m.attrs, "\t", types, Some(&meth_gen_types), m.sig.inputs.iter(), &m.sig.output);
 261
 262                                 if let syn::ReturnType::Type(_, rtype) = &m.sig.output {
 263                                         if let syn::Type::Reference(r) = &**rtype {
 264                                                 // We have to do quite a dance for trait functions which return references
 265                                                 // - they ultimately require us to have a native Rust object stored inside
 266                                                 // our concrete trait to return a reference to. However, users may wish to
 267                                                 // update the value to be returned each time the function is called (or, to
 268                                                 // make C copies of Rust impls equivalent, we have to be able to).
 269                                                 //
 270                                                 // Thus, we store a copy of the C-mapped type (which is just a pointer to
 271                                                 // the Rust type and a flag to indicate whether deallocation needs to
 272                                                 // happen) as well as provide an Option<>al function pointer which is
 273                                                 // called when the trait method is called which allows updating on the fly.
 274                                                 write!(w, "\tpub {}: ", m.sig.ident).unwrap();
 275                                                 generated_fields.push((format!("{}", m.sig.ident), None, None));
 276                                                 types.write_c_type(w, &*r.elem, Some(&meth_gen_types), false);
 277                                                 writeln!(w, ",").unwrap();
 278                                                 writeln!(w, "\t/// Fill in the {} field as a reference to it will be given to Rust after this returns", m.sig.ident).unwrap();
 279                                                 writeln!(w, "\t/// Note that this takes a pointer to this object, not the this_ptr like other methods do").unwrap();
 280                                                 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();
 281                                                 writeln!(w, "\tpub set_{}: Option<extern \"C\" fn(&{})>,", m.sig.ident, trait_name).unwrap();
 282                                                 generated_fields.push((format!("set_{}", m.sig.ident), None, None));
 283                                                 // Note that cbindgen will now generate
 284                                                 // typedef struct Thing {..., set_thing: (const struct Thing*), ...} Thing;
 285                                                 // which does not compile since Thing is not defined before it is used.
 286                                                 writeln!(extra_headers, "struct LDK{};", trait_name).unwrap();
 287                                                 continue;
 288                                         }
 289                                         // Sadly, this currently doesn't do what we want, but it should be easy to get
 290                                         // cbindgen to support it. See https://github.com/eqrion/cbindgen/issues/531
 291                                         writeln!(w, "\t#[must_use]").unwrap();
 292                                 }
 293
 294                                 let mut cpp_docs = Vec::new();
 295                                 writeln_fn_docs(&mut cpp_docs, &m.attrs, "\t * ", types, Some(&meth_gen_types), m.sig.inputs.iter(), &m.sig.output);
 296                                 let docs_string = "\t/**\n".to_owned() + &String::from_utf8(cpp_docs).unwrap().replace("///", "") + "\t */\n";
 297
 298                                 write!(w, "\tpub {}: extern \"C\" fn (", m.sig.ident).unwrap();
 299                                 generated_fields.push((format!("{}", m.sig.ident), None, Some(docs_string)));
 300                                 write_method_params(w, &m.sig, "c_void", types, Some(&meth_gen_types), true, false);
 301                                 writeln!(w, ",").unwrap();
 302                         },
 303                         &syn::TraitItem::Type(_) => {},
 304                         _ => unimplemented!(),
 305                 }
 306         }
 307         // Add functions which may be required for supertrait implementations.
 308         walk_supertraits!(t, Some(&types), (
 309                 ("Clone", _) => {
 310                         writeln!(w, "\t/// Called, if set, after this {} has been cloned into a duplicate object.", trait_name).unwrap();
 311                         writeln!(w, "\t/// The new {} is provided, and should be mutated as needed to perform a", trait_name).unwrap();
 312                         writeln!(w, "\t/// deep copy of the object pointed to by this_arg or avoid any double-freeing.").unwrap();
 313                         writeln!(w, "\tpub cloned: Option<extern \"C\" fn (new_{}: &mut {})>,", trait_name, trait_name).unwrap();
 314                         generated_fields.push(("cloned".to_owned(), None, None));
 315                 },
 316                 ("std::cmp::Eq", _)|("core::cmp::Eq", _) => {
 317                         let eq_docs = "Checks if two objects are equal given this object's this_arg pointer and another object.";
 318                         writeln!(w, "\t/// {}", eq_docs).unwrap();
 319                         writeln!(w, "\tpub eq: extern \"C\" fn (this_arg: *const c_void, other_arg: &{}) -> bool,", trait_name).unwrap();
 320                         generated_fields.push(("eq".to_owned(), None, Some(format!("\t/** {} */\n", eq_docs))));
 321                 },
 322                 ("std::hash::Hash", _)|("core::hash::Hash", _) => {
 323                         let hash_docs_a = "Calculate a succinct non-cryptographic hash for an object given its this_arg pointer.";
 324                         let hash_docs_b = "This is used, for example, for inclusion of this object in a hash map.";
 325                         writeln!(w, "\t/// {}", hash_docs_a).unwrap();
 326                         writeln!(w, "\t/// {}", hash_docs_b).unwrap();
 327                         writeln!(w, "\tpub hash: extern \"C\" fn (this_arg: *const c_void) -> u64,").unwrap();
 328                         generated_fields.push(("hash".to_owned(), None,
 329                                 Some(format!("\t/**\n\t * {}\n\t * {}\n\t */\n", hash_docs_a, hash_docs_b))));
 330                 },
 331                 ("Send", _) => {}, ("Sync", _) => {},
 332                 ("std::fmt::Debug", _)|("core::fmt::Debug", _) => {
 333                         let debug_docs = "Return a human-readable \"debug\" string describing this object";
 334                         writeln!(w, "\t/// {}", debug_docs).unwrap();
 335                         writeln!(w, "\tpub debug_str: extern \"C\" fn (this_arg: *const c_void) -> crate::c_types::Str,").unwrap();
 336                         generated_fields.push(("debug_str".to_owned(), None,
 337                                 Some(format!("\t/**\n\t * {}\n\t */\n", debug_docs))));
 338                 },
 339                 (s, i) => {
 340                         // TODO: Both of the below should expose supertrait methods in C++, but doing so is
 341                         // nontrivial.
 342                         generated_fields.push(if types.crate_types.traits.get(s).is_none() {
 343                                 let (docs, name, ret) = convert_trait_impl_field(s);
 344                                 writeln!(w, "\t/// {}", docs).unwrap();
 345                                 writeln!(w, "\tpub {}: extern \"C\" fn (this_arg: *const c_void) -> {},", name, ret).unwrap();
 346                                 (name, None, None) // Assume clonable
 347                         } else {
 348                                 // For in-crate supertraits, just store a C-mapped copy of the supertrait as a member.
 349                                 writeln!(w, "\t/// Implementation of {} for this object.", i).unwrap();
 350                                 let is_clonable = types.is_clonable(s);
 351                                 writeln!(w, "\tpub {}: crate::{},", i, s).unwrap();
 352                                 (format!("{}", i), if !is_clonable {
 353                                         Some(format!("crate::{}_clone_fields", s))
 354                                 } else { None }, None)
 355                         });
 356                 }
 357         ) );
 358         writeln!(w, "\t/// Frees any resources associated with this object given its this_arg pointer.").unwrap();
 359         writeln!(w, "\t/// Does not need to free the outer struct containing function pointers and may be NULL is no resources need to be freed.").unwrap();
 360         writeln!(w, "\tpub free: Option<extern \"C\" fn(this_arg: *mut c_void)>,").unwrap();
 361         generated_fields.push(("free".to_owned(), None, None));
 362         writeln!(w, "}}").unwrap();
 363
 364         macro_rules! impl_trait_for_c {
 365                 ($t: expr, $impl_accessor: expr, $type_resolver: expr) => {
 366                         for item in $t.items.iter() {
 367                                 match item {
 368                                         syn::TraitItem::Method(m) => {
 369                                                 if let ExportStatus::TestOnly = export_status(&m.attrs) { continue; }
 370                                                 if m.default.is_some() { unimplemented!(); }
 371                                                 if m.sig.constness.is_some() || m.sig.asyncness.is_some() || m.sig.unsafety.is_some() ||
 372                                                                 m.sig.abi.is_some() || m.sig.variadic.is_some() {
 373                                                         unimplemented!();
 374                                                 }
 375                                                 let mut meth_gen_types = gen_types.push_ctx();
 376                                                 assert!(meth_gen_types.learn_generics(&m.sig.generics, $type_resolver));
 377                                                 write!(w, "\tfn {}", m.sig.ident).unwrap();
 378                                                 $type_resolver.write_rust_generic_param(w, Some(&meth_gen_types), m.sig.generics.params.iter());
 379                                                 write!(w, "(").unwrap();
 380                                                 for inp in m.sig.inputs.iter() {
 381                                                         match inp {
 382                                                                 syn::FnArg::Receiver(recv) => {
 383                                                                         if !recv.attrs.is_empty() || recv.reference.is_none() { unimplemented!(); }
 384                                                                         write!(w, "&").unwrap();
 385                                                                         if let Some(lft) = &recv.reference.as_ref().unwrap().1 {
 386                                                                                 write!(w, "'{} ", lft.ident).unwrap();
 387                                                                         }
 388                                                                         if recv.mutability.is_some() {
 389                                                                                 write!(w, "mut self").unwrap();
 390                                                                         } else {
 391                                                                                 write!(w, "self").unwrap();
 392                                                                         }
 393                                                                 },
 394                                                                 syn::FnArg::Typed(arg) => {
 395                                                                         if !arg.attrs.is_empty() { unimplemented!(); }
 396                                                                         match &*arg.pat {
 397                                                                                 syn::Pat::Ident(ident) => {
 398                                                                                         if !ident.attrs.is_empty() || ident.by_ref.is_some() ||
 399                                                                                                         ident.mutability.is_some() || ident.subpat.is_some() {
 400                                                                                                 unimplemented!();
 401                                                                                         }
 402                                                                                         write!(w, ", mut {}{}: ", if $type_resolver.skip_arg(&*arg.ty, Some(&meth_gen_types)) { "_" } else { "" }, ident.ident).unwrap();
 403                                                                                 }
 404                                                                                 _ => unimplemented!(),
 405                                                                         }
 406                                                                         $type_resolver.write_rust_type(w, Some(&meth_gen_types), &*arg.ty);
 407                                                                 }
 408                                                         }
 409                                                 }
 410                                                 write!(w, ")").unwrap();
 411                                                 match &m.sig.output {
 412                                                         syn::ReturnType::Type(_, rtype) => {
 413                                                                 write!(w, " -> ").unwrap();
 414                                                                 $type_resolver.write_rust_type(w, Some(&meth_gen_types), &*rtype)
 415                                                         },
 416                                                         _ => {},
 417                                                 }
 418                                                 write!(w, " {{\n\t\t").unwrap();
 419                                                 match export_status(&m.attrs) {
 420                                                         ExportStatus::NoExport => {
 421                                                                 unimplemented!();
 422                                                         },
 423                                                         _ => {},
 424                                                 }
 425                                                 if let syn::ReturnType::Type(_, rtype) = &m.sig.output {
 426                                                         if let syn::Type::Reference(r) = &**rtype {
 427                                                                 assert_eq!(m.sig.inputs.len(), 1); // Must only take self!
 428                                                                 writeln!(w, "if let Some(f) = self{}.set_{} {{", $impl_accessor, m.sig.ident).unwrap();
 429                                                                 writeln!(w, "\t\t\t(f)(&self{});", $impl_accessor).unwrap();
 430                                                                 write!(w, "\t\t}}\n\t\t").unwrap();
 431                                                                 $type_resolver.write_from_c_conversion_to_ref_prefix(w, &*r.elem, Some(&meth_gen_types));
 432                                                                 write!(w, "self{}.{}", $impl_accessor, m.sig.ident).unwrap();
 433                                                                 $type_resolver.write_from_c_conversion_to_ref_suffix(w, &*r.elem, Some(&meth_gen_types));
 434                                                                 writeln!(w, "\n\t}}").unwrap();
 435                                                                 continue;
 436                                                         }
 437                                                 }
 438                                                 write_method_var_decl_body(w, &m.sig, "\t", $type_resolver, Some(&meth_gen_types), true);
 439                                                 write!(w, "(self{}.{})(", $impl_accessor, m.sig.ident).unwrap();
 440                                                 let mut args = Vec::new();
 441                                                 write_method_call_params(&mut args, &m.sig, "\t", $type_resolver, Some(&meth_gen_types), "", true);
 442                                                 w.write_all(String::from_utf8(args).unwrap().replace("self", &format!("self{}", $impl_accessor)).as_bytes()).unwrap();
 443
 444                                                 writeln!(w, "\n\t}}").unwrap();
 445                                         },
 446                                         &syn::TraitItem::Type(ref t) => {
 447                                                 if t.default.is_some() || t.generics.lt_token.is_some() { unimplemented!(); }
 448                                                 let mut bounds_iter = t.bounds.iter();
 449                                                 match bounds_iter.next().unwrap() {
 450                                                         syn::TypeParamBound::Trait(tr) => {
 451                                                                 writeln!(w, "\ttype {} = crate::{};", t.ident, $type_resolver.resolve_path(&tr.path, Some(&gen_types))).unwrap();
 452                                                         },
 453                                                         _ => unimplemented!(),
 454                                                 }
 455                                                 if bounds_iter.next().is_some() { unimplemented!(); }
 456                                         },
 457                                         _ => unimplemented!(),
 458                                 }
 459                         }
 460                 }
 461         }
 462
 463         writeln!(w, "unsafe impl Send for {} {{}}", trait_name).unwrap();
 464         writeln!(w, "unsafe impl Sync for {} {{}}", trait_name).unwrap();
 465
 466         writeln!(w, "#[no_mangle]").unwrap();
 467         writeln!(w, "pub(crate) extern \"C\" fn {}_clone_fields(orig: &{}) -> {} {{", trait_name, trait_name, trait_name).unwrap();
 468         writeln!(w, "\t{} {{", trait_name).unwrap();
 469         writeln!(w, "\t\tthis_arg: orig.this_arg,").unwrap();
 470         for (field, clone_fn, _) in generated_fields.iter() {
 471                 if let Some(f) = clone_fn {
 472                         // If the field isn't clonable, blindly assume its a trait and hope for the best.
 473                         writeln!(w, "\t\t{}: {}(&orig.{}),", field, f, field).unwrap();
 474                 } else {
 475                         writeln!(w, "\t\t{}: Clone::clone(&orig.{}),", field, field).unwrap();
 476                 }
 477         }
 478         writeln!(w, "\t}}\n}}").unwrap();
 479
 480         // Implement supertraits for the C-mapped struct.
 481         walk_supertraits!(t, Some(&types), (
 482                 ("std::cmp::Eq", _)|("core::cmp::Eq", _) => {
 483                         writeln!(w, "impl std::cmp::Eq for {} {{}}", trait_name).unwrap();
 484                         writeln!(w, "impl std::cmp::PartialEq for {} {{", trait_name).unwrap();
 485                         writeln!(w, "\tfn eq(&self, o: &Self) -> bool {{ (self.eq)(self.this_arg, o) }}\n}}").unwrap();
 486                 },
 487                 ("std::hash::Hash", _)|("core::hash::Hash", _) => {
 488                         writeln!(w, "impl std::hash::Hash for {} {{", trait_name).unwrap();
 489                         writeln!(w, "\tfn hash<H: std::hash::Hasher>(&self, hasher: &mut H) {{ hasher.write_u64((self.hash)(self.this_arg)) }}\n}}").unwrap();
 490                 },
 491                 ("Send", _) => {}, ("Sync", _) => {},
 492                 ("Clone", _) => {
 493                         writeln!(w, "#[no_mangle]").unwrap();
 494                         writeln!(w, "/// Creates a copy of a {}", trait_name).unwrap();
 495                         writeln!(w, "pub extern \"C\" fn {}_clone(orig: &{}) -> {} {{", trait_name, trait_name, trait_name).unwrap();
 496                         writeln!(w, "\tlet mut res = {}_clone_fields(orig);", trait_name).unwrap();
 497                         writeln!(w, "\tif let Some(f) = orig.cloned {{ (f)(&mut res) }};").unwrap();
 498                         writeln!(w, "\tres\n}}").unwrap();
 499                         writeln!(w, "impl Clone for {} {{", trait_name).unwrap();
 500                         writeln!(w, "\tfn clone(&self) -> Self {{").unwrap();
 501                         writeln!(w, "\t\t{}_clone(self)", trait_name).unwrap();
 502                         writeln!(w, "\t}}\n}}").unwrap();
 503                 },
 504                 ("std::fmt::Debug", _)|("core::fmt::Debug", _) => {
 505                         writeln!(w, "impl core::fmt::Debug for {} {{", trait_name).unwrap();
 506                         writeln!(w, "\tfn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {{").unwrap();
 507                         writeln!(w, "\t\tf.write_str((self.debug_str)(self.this_arg).into_str())").unwrap();
 508                         writeln!(w, "\t}}").unwrap();
 509                         writeln!(w, "}}").unwrap();
 510                 },
 511                 (s, i) => {
 512                         if let Some(supertrait) = types.crate_types.traits.get(s) {
 513                                 let mut module_iter = s.rsplitn(2, "::");
 514                                 module_iter.next().unwrap();
 515                                 let supertrait_module = module_iter.next().unwrap();
 516                                 let imports = ImportResolver::new(supertrait_module.splitn(2, "::").next().unwrap(), &types.crate_types.lib_ast.dependencies,
 517                                         supertrait_module, &types.crate_types.lib_ast.modules.get(supertrait_module).unwrap().items);
 518                                 let resolver = TypeResolver::new(&supertrait_module, imports, types.crate_types);
 519                                 writeln!(w, "impl {} for {} {{", s, trait_name).unwrap();
 520                                 impl_trait_for_c!(supertrait, format!(".{}", i), &resolver);
 521                                 writeln!(w, "}}").unwrap();
 522                         } else {
 523                                 do_write_impl_trait(w, s, i, &trait_name);
 524                         }
 525                 }
 526         ) );
 527
 528         // Finally, implement the original Rust trait for the newly created mapped trait.
 529         writeln!(w, "\nuse {}::{} as rust{};", types.module_path, t.ident, trait_name).unwrap();
 530         if implementable {
 531                 write!(w, "impl rust{}", t.ident).unwrap();
 532                 maybe_write_generics(w, &t.generics, types, false);
 533                 writeln!(w, " for {} {{", trait_name).unwrap();
 534                 impl_trait_for_c!(t, "", types);
 535                 writeln!(w, "}}\n").unwrap();
 536                 writeln!(w, "// We're essentially a pointer already, or at least a set of pointers, so allow us to be used").unwrap();
 537                 writeln!(w, "// directly as a Deref trait in higher-level structs:").unwrap();
 538                 writeln!(w, "impl std::ops::Deref for {} {{\n\ttype Target = Self;", trait_name).unwrap();
 539                 writeln!(w, "\tfn deref(&self) -> &Self {{\n\t\tself\n\t}}\n}}").unwrap();
 540         }
 541
 542         writeln!(w, "/// Calls the free function if one is set").unwrap();
 543         writeln!(w, "#[no_mangle]\npub extern \"C\" fn {}_free(this_ptr: {}) {{ }}", trait_name, trait_name).unwrap();
 544         writeln!(w, "impl Drop for {} {{", trait_name).unwrap();
 545         writeln!(w, "\tfn drop(&mut self) {{").unwrap();
 546         writeln!(w, "\t\tif let Some(f) = self.free {{").unwrap();
 547         writeln!(w, "\t\t\tf(self.this_arg);").unwrap();
 548         writeln!(w, "\t\t}}\n\t}}\n}}").unwrap();
 549
 550         write_cpp_wrapper(cpp_headers, &trait_name, true, Some(generated_fields.drain(..)
 551                 .filter_map(|(name, _, docs)| if let Some(docs) = docs { Some((name, docs)) } else { None }).collect()));
 552 }
 553
 554 /// Write out a simple "opaque" type (eg structs) which contain a pointer to the native Rust type
 555 /// and a flag to indicate whether Drop'ing the mapped struct drops the underlying Rust type.
 556 ///
 557 /// Also writes out a _free function and a C++ wrapper which handles calling _free.
 558 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) {
 559         // If we directly read the original type by its original name, cbindgen hits
 560         // https://github.com/eqrion/cbindgen/issues/286 Thus, instead, we import it as a temporary
 561         // name and then reference it by that name, which works around the issue.
 562         write!(w, "\nuse {}::{} as native{}Import;\ntype native{} = native{}Import", types.module_path, ident, ident, ident, ident).unwrap();
 563         maybe_write_generics(w, &generics, &types, true);
 564         writeln!(w, ";\n").unwrap();
 565         writeln!(extra_headers, "struct native{}Opaque;\ntypedef struct native{}Opaque LDKnative{};", ident, ident, ident).unwrap();
 566         writeln_docs(w, &attrs, "");
 567         writeln!(w, "#[must_use]\n#[repr(C)]\npub struct {} {{", struct_name).unwrap();
 568         writeln!(w, "\t/// A pointer to the opaque Rust object.\n").unwrap();
 569         writeln!(w, "\t/// Nearly everywhere, inner must be non-null, however in places where").unwrap();
 570         writeln!(w, "\t/// the Rust equivalent takes an Option, it may be set to null to indicate None.").unwrap();
 571         writeln!(w, "\tpub inner: *mut native{},", ident).unwrap();
 572         writeln!(w, "\t/// Indicates that this is the only struct which contains the same pointer.\n").unwrap();
 573         writeln!(w, "\t/// Rust functions which take ownership of an object provided via an argument require").unwrap();
 574         writeln!(w, "\t/// this to be true and invalidate the object pointed to by inner.").unwrap();
 575         writeln!(w, "\tpub is_owned: bool,").unwrap();
 576         writeln!(w, "}}\n").unwrap();
 577         writeln!(w, "impl Drop for {} {{\n\tfn drop(&mut self) {{", struct_name).unwrap();
 578         writeln!(w, "\t\tif self.is_owned && !<*mut native{}>::is_null(self.inner) {{", ident).unwrap();
 579         writeln!(w, "\t\t\tlet _ = unsafe {{ Box::from_raw(ObjOps::untweak_ptr(self.inner)) }};\n\t\t}}\n\t}}\n}}").unwrap();
 580         writeln!(w, "/// Frees any resources used by the {}, if is_owned is set and inner is non-NULL.", struct_name).unwrap();
 581         writeln!(w, "#[no_mangle]\npub extern \"C\" fn {}_free(this_obj: {}) {{ }}", struct_name, struct_name).unwrap();
 582         writeln!(w, "#[allow(unused)]").unwrap();
 583         writeln!(w, "/// Used only if an object of this type is returned as a trait impl by a method").unwrap();
 584         writeln!(w, "extern \"C\" fn {}_free_void(this_ptr: *mut c_void) {{", struct_name).unwrap();
 585         writeln!(w, "\tunsafe {{ let _ = Box::from_raw(this_ptr as *mut native{}); }}\n}}", struct_name).unwrap();
 586         writeln!(w, "#[allow(unused)]").unwrap();
 587         writeln!(w, "impl {} {{", struct_name).unwrap();
 588         writeln!(w, "\tpub(crate) fn get_native_ref(&self) -> &'static native{} {{", struct_name).unwrap();
 589         writeln!(w, "\t\tunsafe {{ &*ObjOps::untweak_ptr(self.inner) }}").unwrap();
 590         writeln!(w, "\t}}").unwrap();
 591         writeln!(w, "\tpub(crate) fn get_native_mut_ref(&self) -> &'static mut native{} {{", struct_name).unwrap();
 592         writeln!(w, "\t\tunsafe {{ &mut *ObjOps::untweak_ptr(self.inner) }}").unwrap();
 593         writeln!(w, "\t}}").unwrap();
 594         writeln!(w, "\t/// When moving out of the pointer, we have to ensure we aren't a reference, this makes that easy").unwrap();
 595         writeln!(w, "\tpub(crate) fn take_inner(mut self) -> *mut native{} {{", struct_name).unwrap();
 596         writeln!(w, "\t\tassert!(self.is_owned);").unwrap();
 597         writeln!(w, "\t\tlet ret = ObjOps::untweak_ptr(self.inner);").unwrap();
 598         writeln!(w, "\t\tself.inner = std::ptr::null_mut();").unwrap();
 599         writeln!(w, "\t\tret").unwrap();
 600         writeln!(w, "\t}}\n}}").unwrap();
 601
 602         write_cpp_wrapper(cpp_headers, &format!("{}", ident), true, None);
 603 }
 604
 605 /// Writes out all the relevant mappings for a Rust struct, deferring to writeln_opaque to generate
 606 /// the struct itself, and then writing getters and setters for public, understood-type fields and
 607 /// a constructor if every field is public.
 608 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) {
 609         if export_status(&s.attrs) != ExportStatus::Export { return; }
 610
 611         let struct_name = &format!("{}", s.ident);
 612         writeln_opaque(w, &s.ident, struct_name, &s.generics, &s.attrs, types, extra_headers, cpp_headers);
 613
 614         if let syn::Fields::Named(fields) = &s.fields {
 615                 let mut self_path_segs = syn::punctuated::Punctuated::new();
 616                 self_path_segs.push(s.ident.clone().into());
 617                 let self_path = syn::Path { leading_colon: None, segments: self_path_segs};
 618                 let mut gen_types = GenericTypes::new(Some((types.resolve_path(&self_path, None), &self_path)));
 619                 assert!(gen_types.learn_generics(&s.generics, types));
 620
 621                 let mut all_fields_settable = true;
 622                 for field in fields.named.iter() {
 623                         if let syn::Visibility::Public(_) = field.vis {
 624                                 let export = export_status(&field.attrs);
 625                                 match export {
 626                                         ExportStatus::Export => {},
 627                                         ExportStatus::NoExport|ExportStatus::TestOnly => {
 628                                                 all_fields_settable = false;
 629                                                 continue
 630                                         },
 631                                         ExportStatus::NotImplementable => panic!("(C-not implementable) must only appear on traits"),
 632                                 }
 633
 634                                 if let Some(ident) = &field.ident {
 635                                         if let Some(ref_type) = types.create_ownable_reference(&field.ty, Some(&gen_types)) {
 636                                                 if types.understood_c_type(&ref_type, Some(&gen_types)) {
 637                                                         writeln_arg_docs(w, &field.attrs, "", types, Some(&gen_types), vec![].drain(..), Some(&ref_type));
 638                                                         write!(w, "#[no_mangle]\npub extern \"C\" fn {}_get_{}(this_ptr: &{}) -> ", struct_name, ident, struct_name).unwrap();
 639                                                         types.write_c_type(w, &ref_type, Some(&gen_types), true);
 640                                                         write!(w, " {{\n\tlet mut inner_val = &mut this_ptr.get_native_mut_ref().{};\n\t", ident).unwrap();
 641                                                         let local_var = types.write_to_c_conversion_new_var(w, &format_ident!("inner_val"), &ref_type, Some(&gen_types), true);
 642                                                         if local_var { write!(w, "\n\t").unwrap(); }
 643                                                         types.write_to_c_conversion_inline_prefix(w, &ref_type, Some(&gen_types), true);
 644                                                         write!(w, "inner_val").unwrap();
 645                                                         types.write_to_c_conversion_inline_suffix(w, &ref_type, Some(&gen_types), true);
 646                                                         writeln!(w, "\n}}").unwrap();
 647                                                 }
 648                                         }
 649
 650                                         if types.understood_c_type(&field.ty, Some(&gen_types)) {
 651                                                 writeln_arg_docs(w, &field.attrs, "", types, Some(&gen_types), vec![("val".to_owned(), &field.ty)].drain(..), None);
 652                                                 write!(w, "#[no_mangle]\npub extern \"C\" fn {}_set_{}(this_ptr: &mut {}, mut val: ", struct_name, ident, struct_name).unwrap();
 653                                                 types.write_c_type(w, &field.ty, Some(&gen_types), false);
 654                                                 write!(w, ") {{\n\t").unwrap();
 655                                                 let local_var = types.write_from_c_conversion_new_var(w, &format_ident!("val"), &field.ty, Some(&gen_types));
 656                                                 if local_var { write!(w, "\n\t").unwrap(); }
 657                                                 write!(w, "unsafe {{ &mut *ObjOps::untweak_ptr(this_ptr.inner) }}.{} = ", ident).unwrap();
 658                                                 types.write_from_c_conversion_prefix(w, &field.ty, Some(&gen_types));
 659                                                 write!(w, "val").unwrap();
 660                                                 types.write_from_c_conversion_suffix(w, &field.ty, Some(&gen_types));
 661                                                 writeln!(w, ";\n}}").unwrap();
 662                                         } else { all_fields_settable = false; }
 663                                 } else { all_fields_settable = false; }
 664                         } else { all_fields_settable = false; }
 665                 }
 666
 667                 if all_fields_settable {
 668                         // Build a constructor!
 669                         writeln!(w, "/// Constructs a new {} given each field", struct_name).unwrap();
 670                         write!(w, "#[must_use]\n#[no_mangle]\npub extern \"C\" fn {}_new(", struct_name).unwrap();
 671                         for (idx, field) in fields.named.iter().enumerate() {
 672                                 if idx != 0 { write!(w, ", ").unwrap(); }
 673                                 write!(w, "mut {}_arg: ", field.ident.as_ref().unwrap()).unwrap();
 674                                 types.write_c_type(w, &field.ty, Some(&gen_types), false);
 675                         }
 676                         write!(w, ") -> {} {{\n\t", struct_name).unwrap();
 677                         for field in fields.named.iter() {
 678                                 let field_ident = format_ident!("{}_arg", field.ident.as_ref().unwrap());
 679                                 if types.write_from_c_conversion_new_var(w, &field_ident, &field.ty, Some(&gen_types)) {
 680                                         write!(w, "\n\t").unwrap();
 681                                 }
 682                         }
 683                         writeln!(w, "{} {{ inner: ObjOps::heap_alloc(native{} {{", struct_name, s.ident).unwrap();
 684                         for field in fields.named.iter() {
 685                                 write!(w, "\t\t{}: ", field.ident.as_ref().unwrap()).unwrap();
 686                                 types.write_from_c_conversion_prefix(w, &field.ty, Some(&gen_types));
 687                                 write!(w, "{}_arg", field.ident.as_ref().unwrap()).unwrap();
 688                                 types.write_from_c_conversion_suffix(w, &field.ty, Some(&gen_types));
 689                                 writeln!(w, ",").unwrap();
 690                         }
 691                         writeln!(w, "\t}}), is_owned: true }}\n}}").unwrap();
 692                 }
 693         }
 694 }
 695
 696 /// Prints a relevant conversion for impl *
 697 ///
 698 /// For simple impl Struct {}s, this just outputs the wrapper functions as Struct_fn_name() { .. }.
 699 ///
 700 /// For impl Trait for Struct{}s, this non-exported generates wrapper functions as
 701 /// Trait_Struct_fn_name and a Struct_as_Trait(&struct) -> Trait function which returns a populated
 702 /// Trait struct containing a pointer to the passed struct's inner field and the wrapper functions.
 703 ///
 704 /// A few non-crate Traits are hard-coded including Default.
 705 fn writeln_impl<W: std::io::Write>(w: &mut W, i: &syn::ItemImpl, types: &mut TypeResolver) {
 706         match export_status(&i.attrs) {
 707                 ExportStatus::Export => {},
 708                 ExportStatus::NoExport|ExportStatus::TestOnly => return,
 709                 ExportStatus::NotImplementable => panic!("(C-not implementable) must only appear on traits"),
 710         }
 711
 712         if let syn::Type::Tuple(_) = &*i.self_ty {
 713                 if types.understood_c_type(&*i.self_ty, None) {
 714                         let mut gen_types = GenericTypes::new(None);
 715                         if !gen_types.learn_generics(&i.generics, types) {
 716                                 eprintln!("Not implementing anything for `impl (..)` due to not understood generics");
 717                                 return;
 718                         }
 719
 720                         if i.defaultness.is_some() || i.unsafety.is_some() { unimplemented!(); }
 721                         if let Some(trait_path) = i.trait_.as_ref() {
 722                                 if trait_path.0.is_some() { unimplemented!(); }
 723                                 if types.understood_c_path(&trait_path.1) {
 724                                         eprintln!("Not implementing anything for `impl Trait for (..)` - we only support manual defines");
 725                                         return;
 726                                 } else {
 727                                         // Just do a manual implementation:
 728                                         maybe_convert_trait_impl(w, &trait_path.1, &*i.self_ty, types, &gen_types);
 729                                 }
 730                         } else {
 731                                 eprintln!("Not implementing anything for plain `impl (..)` block - we only support `impl Trait for (..)` blocks");
 732                                 return;
 733                         }
 734                 }
 735                 return;
 736         }
 737         if let &syn::Type::Path(ref p) = &*i.self_ty {
 738                 if p.qself.is_some() { unimplemented!(); }
 739                 if let Some(ident) = single_ident_generic_path_to_ident(&p.path) {
 740                         if let Some(resolved_path) = types.maybe_resolve_non_ignored_ident(&ident) {
 741                                 let mut gen_types = GenericTypes::new(Some((resolved_path.clone(), &p.path)));
 742                                 if !gen_types.learn_generics(&i.generics, types) {
 743                                         eprintln!("Not implementing anything for impl {} due to not understood generics", ident);
 744                                         return;
 745                                 }
 746
 747                                 if i.defaultness.is_some() || i.unsafety.is_some() { unimplemented!(); }
 748                                 if let Some(trait_path) = i.trait_.as_ref() {
 749                                         if trait_path.0.is_some() { unimplemented!(); }
 750                                         if types.understood_c_path(&trait_path.1) {
 751                                                 let full_trait_path = types.resolve_path(&trait_path.1, None);
 752                                                 let trait_obj = *types.crate_types.traits.get(&full_trait_path).unwrap();
 753                                                 // We learn the associated types maping from the original trait object.
 754                                                 // That's great, except that they are unresolved idents, so if we learn
 755                                                 // mappings from a trai defined in a different file, we may mis-resolve or
 756                                                 // fail to resolve the mapped types.
 757                                                 gen_types.learn_associated_types(trait_obj, types);
 758                                                 let mut impl_associated_types = HashMap::new();
 759                                                 for item in i.items.iter() {
 760                                                         match item {
 761                                                                 syn::ImplItem::Type(t) => {
 762                                                                         if let syn::Type::Path(p) = &t.ty {
 763                                                                                 if let Some(id) = single_ident_generic_path_to_ident(&p.path) {
 764                                                                                         impl_associated_types.insert(&t.ident, id);
 765                                                                                 }
 766                                                                         }
 767                                                                 },
 768                                                                 _ => {},
 769                                                         }
 770                                                 }
 771
 772                                                 let export = export_status(&trait_obj.attrs);
 773                                                 match export {
 774                                                         ExportStatus::Export|ExportStatus::NotImplementable => {},
 775                                                         ExportStatus::NoExport|ExportStatus::TestOnly => return,
 776                                                 }
 777
 778                                                 // For cases where we have a concrete native object which implements a
 779                                                 // trait and need to return the C-mapped version of the trait, provide a
 780                                                 // From<> implementation which does all the work to ensure free is handled
 781                                                 // properly. This way we can call this method from deep in the
 782                                                 // type-conversion logic without actually knowing the concrete native type.
 783                                                 writeln!(w, "impl From<native{}> for crate::{} {{", ident, full_trait_path).unwrap();
 784                                                 writeln!(w, "\tfn from(obj: native{}) -> Self {{", ident).unwrap();
 785                                                 writeln!(w, "\t\tlet mut rust_obj = {} {{ inner: ObjOps::heap_alloc(obj), is_owned: true }};", ident).unwrap();
 786                                                 writeln!(w, "\t\tlet mut ret = {}_as_{}(&rust_obj);", ident, trait_obj.ident).unwrap();
 787                                                 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();
 788                                                 writeln!(w, "\t\trust_obj.inner = std::ptr::null_mut();").unwrap();
 789                                                 writeln!(w, "\t\tret.free = Some({}_free_void);", ident).unwrap();
 790                                                 writeln!(w, "\t\tret\n\t}}\n}}").unwrap();
 791
 792                                                 writeln!(w, "/// Constructs a new {} which calls the relevant methods on this_arg.", trait_obj.ident).unwrap();
 793                                                 writeln!(w, "/// This copies the `inner` pointer in this_arg and thus the returned {} must be freed before this_arg is", trait_obj.ident).unwrap();
 794                                                 write!(w, "#[no_mangle]\npub extern \"C\" fn {}_as_{}(this_arg: &{}) -> crate::{} {{\n", ident, trait_obj.ident, ident, full_trait_path).unwrap();
 795                                                 writeln!(w, "\tcrate::{} {{", full_trait_path).unwrap();
 796                                                 writeln!(w, "\t\tthis_arg: unsafe {{ ObjOps::untweak_ptr((*this_arg).inner) as *mut c_void }},").unwrap();
 797                                                 writeln!(w, "\t\tfree: None,").unwrap();
 798
 799                                                 macro_rules! write_meth {
 800                                                         ($m: expr, $trait: expr, $indent: expr) => {
 801                                                                 let trait_method = $trait.items.iter().filter_map(|item| {
 802                                                                         if let syn::TraitItem::Method(t_m) = item { Some(t_m) } else { None }
 803                                                                 }).find(|trait_meth| trait_meth.sig.ident == $m.sig.ident).unwrap();
 804                                                                 match export_status(&trait_method.attrs) {
 805                                                                         ExportStatus::Export => {},
 806                                                                         ExportStatus::NoExport => {
 807                                                                                 write!(w, "{}\t\t//XXX: Need to export {}\n", $indent, $m.sig.ident).unwrap();
 808                                                                                 continue;
 809                                                                         },
 810                                                                         ExportStatus::TestOnly => continue,
 811                                                                         ExportStatus::NotImplementable => panic!("(C-not implementable) must only appear on traits"),
 812                                                                 }
 813
 814                                                                 let mut printed = false;
 815                                                                 if let syn::ReturnType::Type(_, rtype) = &$m.sig.output {
 816                                                                         if let syn::Type::Reference(r) = &**rtype {
 817                                                                                 write!(w, "\n\t\t{}{}: ", $indent, $m.sig.ident).unwrap();
 818                                                                                 types.write_empty_rust_val(Some(&gen_types), w, &*r.elem);
 819                                                                                 writeln!(w, ",\n{}\t\tset_{}: Some({}_{}_set_{}),", $indent, $m.sig.ident, ident, $trait.ident, $m.sig.ident).unwrap();
 820                                                                                 printed = true;
 821                                                                         }
 822                                                                 }
 823                                                                 if !printed {
 824                                                                         write!(w, "{}\t\t{}: {}_{}_{},\n", $indent, $m.sig.ident, ident, $trait.ident, $m.sig.ident).unwrap();
 825                                                                 }
 826                                                         }
 827                                                 }
 828                                                 for item in trait_obj.items.iter() {
 829                                                         match item {
 830                                                                 syn::TraitItem::Method(m) => {
 831                                                                         write_meth!(m, trait_obj, "");
 832                                                                 },
 833                                                                 _ => {},
 834                                                         }
 835                                                 }
 836                                                 let mut requires_clone = false;
 837                                                 walk_supertraits!(trait_obj, Some(&types), (
 838                                                         ("Clone", _) => {
 839                                                                 requires_clone = true;
 840                                                                 writeln!(w, "\t\tcloned: Some({}_{}_cloned),", trait_obj.ident, ident).unwrap();
 841                                                         },
 842                                                         ("Sync", _) => {}, ("Send", _) => {},
 843                                                         ("std::marker::Sync", _) => {}, ("std::marker::Send", _) => {},
 844                                                         ("core::fmt::Debug", _) => {},
 845                                                         (s, t) => {
 846                                                                 if let Some(supertrait_obj) = types.crate_types.traits.get(s) {
 847                                                                         writeln!(w, "\t\t{}: crate::{} {{", t, s).unwrap();
 848                                                                         writeln!(w, "\t\t\tthis_arg: unsafe {{ ObjOps::untweak_ptr((*this_arg).inner) as *mut c_void }},").unwrap();
 849                                                                         writeln!(w, "\t\t\tfree: None,").unwrap();
 850                                                                         for item in supertrait_obj.items.iter() {
 851                                                                                 match item {
 852                                                                                         syn::TraitItem::Method(m) => {
 853                                                                                                 write_meth!(m, supertrait_obj, "\t");
 854                                                                                         },
 855                                                                                         _ => {},
 856                                                                                 }
 857                                                                         }
 858                                                                         write!(w, "\t\t}},\n").unwrap();
 859                                                                 } else {
 860                                                                         write_trait_impl_field_assign(w, s, ident);
 861                                                                 }
 862                                                         }
 863                                                 ) );
 864                                                 writeln!(w, "\t}}\n}}\n").unwrap();
 865
 866                                                 macro_rules! impl_meth {
 867                                                         ($m: expr, $trait_path: expr, $trait: expr, $indent: expr) => {
 868                                                                 let trait_method = $trait.items.iter().filter_map(|item| {
 869                                                                         if let syn::TraitItem::Method(t_m) = item { Some(t_m) } else { None }
 870                                                                 }).find(|trait_meth| trait_meth.sig.ident == $m.sig.ident).unwrap();
 871                                                                 match export_status(&trait_method.attrs) {
 872                                                                         ExportStatus::Export => {},
 873                                                                         ExportStatus::NoExport|ExportStatus::TestOnly => continue,
 874                                                                         ExportStatus::NotImplementable => panic!("(C-not implementable) must only appear on traits"),
 875                                                                 }
 876
 877                                                                 if let syn::ReturnType::Type(_, _) = &$m.sig.output {
 878                                                                         writeln!(w, "#[must_use]").unwrap();
 879                                                                 }
 880                                                                 write!(w, "extern \"C\" fn {}_{}_{}(", ident, $trait.ident, $m.sig.ident).unwrap();
 881                                                                 let mut meth_gen_types = gen_types.push_ctx();
 882                                                                 assert!(meth_gen_types.learn_generics(&$m.sig.generics, types));
 883                                                                 write_method_params(w, &$m.sig, "c_void", types, Some(&meth_gen_types), true, true);
 884                                                                 write!(w, " {{\n\t").unwrap();
 885                                                                 write_method_var_decl_body(w, &$m.sig, "", types, Some(&meth_gen_types), false);
 886                                                                 let mut takes_self = false;
 887                                                                 for inp in $m.sig.inputs.iter() {
 888                                                                         if let syn::FnArg::Receiver(_) = inp {
 889                                                                                 takes_self = true;
 890                                                                         }
 891                                                                 }
 892
 893                                                                 let mut t_gen_args = String::new();
 894                                                                 for (idx, _) in $trait.generics.params.iter().enumerate() {
 895                                                                         if idx != 0 { t_gen_args += ", " };
 896                                                                         t_gen_args += "_"
 897                                                                 }
 898                                                                 if takes_self {
 899                                                                         write!(w, "<native{} as {}<{}>>::{}(unsafe {{ &mut *(this_arg as *mut native{}) }}, ", ident, $trait_path, t_gen_args, $m.sig.ident, ident).unwrap();
 900                                                                 } else {
 901                                                                         write!(w, "<native{} as {}<{}>>::{}(", ident, $trait_path, t_gen_args, $m.sig.ident).unwrap();
 902                                                                 }
 903
 904                                                                 let mut real_type = "".to_string();
 905                                                                 match &$m.sig.output {
 906                                                                         syn::ReturnType::Type(_, rtype) => {
 907                                                                                 if let Some(mut remaining_path) = first_seg_self(&*rtype) {
 908                                                                                         if let Some(associated_seg) = get_single_remaining_path_seg(&mut remaining_path) {
 909                                                                                                 real_type = format!("{}", impl_associated_types.get(associated_seg).unwrap());
 910                                                                                         }
 911                                                                                 }
 912                                                                         },
 913                                                                         _ => {},
 914                                                                 }
 915                                                                 write_method_call_params(w, &$m.sig, "", types, Some(&meth_gen_types), &real_type, false);
 916                                                                 write!(w, "\n}}\n").unwrap();
 917                                                                 if let syn::ReturnType::Type(_, rtype) = &$m.sig.output {
 918                                                                         if let syn::Type::Reference(r) = &**rtype {
 919                                                                                 assert_eq!($m.sig.inputs.len(), 1); // Must only take self
 920                                                                                 writeln!(w, "extern \"C\" fn {}_{}_set_{}(trait_self_arg: &{}) {{", ident, $trait.ident, $m.sig.ident, $trait.ident).unwrap();
 921                                                                                 writeln!(w, "\t// This is a bit race-y in the general case, but for our specific use-cases today, we're safe").unwrap();
 922                                                                                 writeln!(w, "\t// Specifically, we must ensure that the first time we're called it can never be in parallel").unwrap();
 923                                                                                 write!(w, "\tif ").unwrap();
 924                                                                                 types.write_empty_rust_val_check(Some(&meth_gen_types), w, &*r.elem, &format!("trait_self_arg.{}", $m.sig.ident));
 925                                                                                 writeln!(w, " {{").unwrap();
 926                                                                                 writeln!(w, "\t\tunsafe {{ &mut *(trait_self_arg as *const {}  as *mut {}) }}.{} = {}_{}_{}(trait_self_arg.this_arg);", $trait.ident, $trait.ident, $m.sig.ident, ident, $trait.ident, $m.sig.ident).unwrap();
 927                                                                                 writeln!(w, "\t}}").unwrap();
 928                                                                                 writeln!(w, "}}").unwrap();
 929                                                                         }
 930                                                                 }
 931                                                         }
 932                                                 }
 933
 934                                                 for item in i.items.iter() {
 935                                                         match item {
 936                                                                 syn::ImplItem::Method(m) => {
 937                                                                         impl_meth!(m, full_trait_path, trait_obj, "");
 938                                                                 },
 939                                                                 syn::ImplItem::Type(_) => {},
 940                                                                 _ => unimplemented!(),
 941                                                         }
 942                                                 }
 943                                                 if requires_clone {
 944                                                         writeln!(w, "extern \"C\" fn {}_{}_cloned(new_obj: &mut crate::{}) {{", trait_obj.ident, ident, full_trait_path).unwrap();
 945                                                         writeln!(w, "\tnew_obj.this_arg = {}_clone_void(new_obj.this_arg);", ident).unwrap();
 946                                                         writeln!(w, "\tnew_obj.free = Some({}_free_void);", ident).unwrap();
 947                                                         walk_supertraits!(trait_obj, Some(&types), (
 948                                                                 (s, t) => {
 949                                                                         if types.crate_types.traits.get(s).is_some() {
 950                                                                                 assert!(!types.is_clonable(s)); // We don't currently support cloning with a clonable supertrait
 951                                                                                 writeln!(w, "\tnew_obj.{}.this_arg = new_obj.this_arg;", t).unwrap();
 952                                                                                 writeln!(w, "\tnew_obj.{}.free = None;", t).unwrap();
 953                                                                         }
 954                                                                 }
 955                                                         ) );
 956                                                         writeln!(w, "}}").unwrap();
 957                                                 }
 958                                                 write!(w, "\n").unwrap();
 959                                         } else if path_matches_nongeneric(&trait_path.1, &["From"]) {
 960                                         } else if path_matches_nongeneric(&trait_path.1, &["Default"]) {
 961                                                 writeln!(w, "/// Creates a \"default\" {}. See struct and individual field documentaiton for details on which values are used.", ident).unwrap();
 962                                                 write!(w, "#[must_use]\n#[no_mangle]\npub extern \"C\" fn {}_default() -> {} {{\n", ident, ident).unwrap();
 963                                                 write!(w, "\t{} {{ inner: ObjOps::heap_alloc(Default::default()), is_owned: true }}\n", ident).unwrap();
 964                                                 write!(w, "}}\n").unwrap();
 965                                         } else if path_matches_nongeneric(&trait_path.1, &["core", "cmp", "PartialEq"]) {
 966                                         } else if path_matches_nongeneric(&trait_path.1, &["core", "cmp", "Eq"]) {
 967                                                 writeln!(w, "/// Checks if two {}s contain equal inner contents.", ident).unwrap();
 968                                                 writeln!(w, "/// This ignores pointers and is_owned flags and looks at the values in fields.").unwrap();
 969                                                 if types.c_type_has_inner_from_path(&resolved_path) {
 970                                                         writeln!(w, "/// Two objects with NULL inner values will be considered \"equal\" here.").unwrap();
 971                                                 }
 972                                                 write!(w, "#[no_mangle]\npub extern \"C\" fn {}_eq(a: &{}, b: &{}) -> bool {{\n", ident, ident, ident).unwrap();
 973                                                 if types.c_type_has_inner_from_path(&resolved_path) {
 974                                                         write!(w, "\tif a.inner == b.inner {{ return true; }}\n").unwrap();
 975                                                         write!(w, "\tif a.inner.is_null() || b.inner.is_null() {{ return false; }}\n").unwrap();
 976                                                 }
 977
 978                                                 let path = &p.path;
 979                                                 let ref_type: syn::Type = syn::parse_quote!(&#path);
 980                                                 assert!(!types.write_to_c_conversion_new_var(w, &format_ident!("a"), &*i.self_ty, Some(&gen_types), false), "We don't support new var conversions when comparing equality");
 981
 982                                                 write!(w, "\tif ").unwrap();
 983                                                 types.write_from_c_conversion_prefix(w, &ref_type, Some(&gen_types));
 984                                                 write!(w, "a").unwrap();
 985                                                 types.write_from_c_conversion_suffix(w, &ref_type, Some(&gen_types));
 986                                                 write!(w, " == ").unwrap();
 987                                                 types.write_from_c_conversion_prefix(w, &ref_type, Some(&gen_types));
 988                                                 write!(w, "b").unwrap();
 989                                                 types.write_from_c_conversion_suffix(w, &ref_type, Some(&gen_types));
 990
 991                                                 writeln!(w, " {{ true }} else {{ false }}\n}}").unwrap();
 992                                         } else if path_matches_nongeneric(&trait_path.1, &["core", "hash", "Hash"]) {
 993                                                 writeln!(w, "/// Checks if two {}s contain equal inner contents.", ident).unwrap();
 994                                                 write!(w, "#[no_mangle]\npub extern \"C\" fn {}_hash(o: &{}) -> u64 {{\n", ident, ident).unwrap();
 995                                                 if types.c_type_has_inner_from_path(&resolved_path) {
 996                                                         write!(w, "\tif o.inner.is_null() {{ return 0; }}\n").unwrap();
 997                                                 }
 998
 999                                                 let path = &p.path;
1000                                                 let ref_type: syn::Type = syn::parse_quote!(&#path);
1001                                                 assert!(!types.write_to_c_conversion_new_var(w, &format_ident!("a"), &*i.self_ty, Some(&gen_types), false), "We don't support new var conversions when comparing equality");
1002
1003                                                 writeln!(w, "\t// Note that we'd love to use std::collections::hash_map::DefaultHasher but it's not in core").unwrap();
1004                                                 writeln!(w, "\t#[allow(deprecated)]").unwrap();
1005                                                 writeln!(w, "\tlet mut hasher = core::hash::SipHasher::new();").unwrap();
1006                                                 write!(w, "\tstd::hash::Hash::hash(").unwrap();
1007                                                 types.write_from_c_conversion_prefix(w, &ref_type, Some(&gen_types));
1008                                                 write!(w, "o").unwrap();
1009                                                 types.write_from_c_conversion_suffix(w, &ref_type, Some(&gen_types));
1010                                                 writeln!(w, ", &mut hasher);").unwrap();
1011                                                 writeln!(w, "\tstd::hash::Hasher::finish(&hasher)\n}}").unwrap();
1012                                         } else if (path_matches_nongeneric(&trait_path.1, &["core", "clone", "Clone"]) || path_matches_nongeneric(&trait_path.1, &["Clone"])) &&
1013                                                         types.c_type_has_inner_from_path(&resolved_path) {
1014                                                 writeln!(w, "impl Clone for {} {{", ident).unwrap();
1015                                                 writeln!(w, "\tfn clone(&self) -> Self {{").unwrap();
1016                                                 writeln!(w, "\t\tSelf {{").unwrap();
1017                                                 writeln!(w, "\t\t\tinner: if <*mut native{}>::is_null(self.inner) {{ std::ptr::null_mut() }} else {{", ident).unwrap();
1018                                                 writeln!(w, "\t\t\t\tObjOps::heap_alloc(unsafe {{ &*ObjOps::untweak_ptr(self.inner) }}.clone()) }},").unwrap();
1019                                                 writeln!(w, "\t\t\tis_owned: true,").unwrap();
1020                                                 writeln!(w, "\t\t}}\n\t}}\n}}").unwrap();
1021                                                 writeln!(w, "#[allow(unused)]").unwrap();
1022                                                 writeln!(w, "/// Used only if an object of this type is returned as a trait impl by a method").unwrap();
1023                                                 writeln!(w, "pub(crate) extern \"C\" fn {}_clone_void(this_ptr: *const c_void) -> *mut c_void {{", ident).unwrap();
1024                                                 writeln!(w, "\tBox::into_raw(Box::new(unsafe {{ (*(this_ptr as *mut native{})).clone() }})) as *mut c_void", ident).unwrap();
1025                                                 writeln!(w, "}}").unwrap();
1026                                                 writeln!(w, "#[no_mangle]").unwrap();
1027                                                 writeln!(w, "/// Creates a copy of the {}", ident).unwrap();
1028                                                 writeln!(w, "pub extern \"C\" fn {}_clone(orig: &{}) -> {} {{", ident, ident, ident).unwrap();
1029                                                 writeln!(w, "\torig.clone()").unwrap();
1030                                                 writeln!(w, "}}").unwrap();
1031                                         } else if path_matches_nongeneric(&trait_path.1, &["FromStr"]) {
1032                                                 if let Some(container) = types.get_c_mangled_container_type(
1033                                                                 vec![&*i.self_ty, &syn::Type::Tuple(syn::TypeTuple { paren_token: Default::default(), elems: syn::punctuated::Punctuated::new() })],
1034                                                                 Some(&gen_types), "Result") {
1035                                                         writeln!(w, "#[no_mangle]").unwrap();
1036                                                         writeln!(w, "/// Read a {} object from a string", ident).unwrap();
1037                                                         writeln!(w, "pub extern \"C\" fn {}_from_str(s: crate::c_types::Str) -> {} {{", ident, container).unwrap();
1038                                                         writeln!(w, "\tmatch {}::from_str(s.into_str()) {{", resolved_path).unwrap();
1039                                                         writeln!(w, "\t\tOk(r) => {{").unwrap();
1040                                                         let new_var = types.write_to_c_conversion_new_var(w, &format_ident!("r"), &*i.self_ty, Some(&gen_types), false);
1041                                                         write!(w, "\t\t\tcrate::c_types::CResultTempl::ok(\n\t\t\t\t").unwrap();
1042                                                         types.write_to_c_conversion_inline_prefix(w, &*i.self_ty, Some(&gen_types), false);
1043                                                         write!(w, "{}r", if new_var { "local_" } else { "" }).unwrap();
1044                                                         types.write_to_c_conversion_inline_suffix(w, &*i.self_ty, Some(&gen_types), false);
1045                                                         writeln!(w, "\n\t\t\t)\n\t\t}},").unwrap();
1046                                                         writeln!(w, "\t\tErr(e) => crate::c_types::CResultTempl::err(()),").unwrap();
1047                                                         writeln!(w, "\t}}.into()\n}}").unwrap();
1048                                                 }
1049                                         } else if path_matches_nongeneric(&trait_path.1, &["Display"]) {
1050                                                 writeln!(w, "#[no_mangle]").unwrap();
1051                                                 writeln!(w, "/// Get the string representation of a {} object", ident).unwrap();
1052                                                 writeln!(w, "pub extern \"C\" fn {}_to_str(o: &crate::{}) -> Str {{", ident, resolved_path).unwrap();
1053
1054                                                 let self_ty = &i.self_ty;
1055                                                 let ref_type: syn::Type = syn::parse_quote!(&#self_ty);
1056                                                 let new_var = types.write_from_c_conversion_new_var(w, &format_ident!("o"), &ref_type, Some(&gen_types));
1057                                                 write!(w, "\tformat!(\"{{}}\", ").unwrap();
1058                                                 types.write_from_c_conversion_prefix(w, &ref_type, Some(&gen_types));
1059                                                 write!(w, "{}o", if new_var { "local_" } else { "" }).unwrap();
1060                                                 types.write_from_c_conversion_suffix(w, &ref_type, Some(&gen_types));
1061                                                 writeln!(w, ").into()").unwrap();
1062
1063                                                 writeln!(w, "}}").unwrap();
1064                                         } else {
1065                                                 //XXX: implement for other things like ToString
1066                                                 // If we have no generics, try a manual implementation:
1067                                                 maybe_convert_trait_impl(w, &trait_path.1, &*i.self_ty, types, &gen_types);
1068                                         }
1069                                 } else {
1070                                         let declared_type = (*types.get_declared_type(&ident).unwrap()).clone();
1071                                         for item in i.items.iter() {
1072                                                 match item {
1073                                                         syn::ImplItem::Method(m) => {
1074                                                                 if let syn::Visibility::Public(_) = m.vis {
1075                                                                         match export_status(&m.attrs) {
1076                                                                                 ExportStatus::Export => {},
1077                                                                                 ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1078                                                                                 ExportStatus::NotImplementable => panic!("(C-not implementable) must only appear on traits"),
1079                                                                         }
1080                                                                         let mut meth_gen_types = gen_types.push_ctx();
1081                                                                         assert!(meth_gen_types.learn_generics(&m.sig.generics, types));
1082                                                                         if m.defaultness.is_some() { unimplemented!(); }
1083                                                                         writeln_fn_docs(w, &m.attrs, "", types, Some(&meth_gen_types), m.sig.inputs.iter(), &m.sig.output);
1084                                                                         if let syn::ReturnType::Type(_, _) = &m.sig.output {
1085                                                                                 writeln!(w, "#[must_use]").unwrap();
1086                                                                         }
1087                                                                         write!(w, "#[no_mangle]\npub extern \"C\" fn {}_{}(", ident, m.sig.ident).unwrap();
1088                                                                         let ret_type = match &declared_type {
1089                                                                                 DeclType::MirroredEnum => format!("{}", ident),
1090                                                                                 DeclType::StructImported => format!("{}", ident),
1091                                                                                 _ => unimplemented!(),
1092                                                                         };
1093                                                                         write_method_params(w, &m.sig, &ret_type, types, Some(&meth_gen_types), false, true);
1094                                                                         write!(w, " {{\n\t").unwrap();
1095                                                                         write_method_var_decl_body(w, &m.sig, "", types, Some(&meth_gen_types), false);
1096                                                                         let mut takes_self = false;
1097                                                                         let mut takes_mut_self = false;
1098                                                                         let mut takes_owned_self = false;
1099                                                                         for inp in m.sig.inputs.iter() {
1100                                                                                 if let syn::FnArg::Receiver(r) = inp {
1101                                                                                         takes_self = true;
1102                                                                                         if r.mutability.is_some() { takes_mut_self = true; }
1103                                                                                         if r.reference.is_none() { takes_owned_self = true; }
1104                                                                                 }
1105                                                                         }
1106                                                                         if !takes_mut_self && !takes_self {
1107                                                                                 write!(w, "{}::{}(", resolved_path, m.sig.ident).unwrap();
1108                                                                         } else {
1109                                                                                 match &declared_type {
1110                                                                                         DeclType::MirroredEnum => write!(w, "this_arg.to_native().{}(", m.sig.ident).unwrap(),
1111                                                                                         DeclType::StructImported => {
1112                                                                                                 if takes_owned_self {
1113                                                                                                         write!(w, "(*unsafe {{ Box::from_raw(this_arg.take_inner()) }}).{}(", m.sig.ident).unwrap();
1114                                                                                                 } else if takes_mut_self {
1115                                                                                                         write!(w, "unsafe {{ &mut (*ObjOps::untweak_ptr(this_arg.inner as *mut native{})) }}.{}(", ident, m.sig.ident).unwrap();
1116                                                                                                 } else {
1117                                                                                                         write!(w, "unsafe {{ &*ObjOps::untweak_ptr(this_arg.inner) }}.{}(", m.sig.ident).unwrap();
1118                                                                                                 }
1119                                                                                         },
1120                                                                                         _ => unimplemented!(),
1121                                                                                 }
1122                                                                         }
1123                                                                         write_method_call_params(w, &m.sig, "", types, Some(&meth_gen_types), &ret_type, false);
1124                                                                         writeln!(w, "\n}}\n").unwrap();
1125                                                                 }
1126                                                         },
1127                                                         _ => {},
1128                                                 }
1129                                         }
1130                                 }
1131                         } else if let Some(resolved_path) = types.maybe_resolve_ident(&ident) {
1132                                 if let Some(aliases) = types.crate_types.reverse_alias_map.get(&resolved_path).cloned() {
1133                                         'alias_impls: for (alias, arguments) in aliases {
1134                                                 let alias_resolved = types.resolve_path(&alias, None);
1135                                                 for (idx, gen) in i.generics.params.iter().enumerate() {
1136                                                         match gen {
1137                                                                 syn::GenericParam::Type(type_param) => {
1138                                                                         'bounds_check: for bound in type_param.bounds.iter() {
1139                                                                                 if let syn::TypeParamBound::Trait(trait_bound) = bound {
1140                                                                                         if let syn::PathArguments::AngleBracketed(ref t) = &arguments {
1141                                                                                                 assert!(idx < t.args.len());
1142                                                                                                 if let syn::GenericArgument::Type(syn::Type::Path(p)) = &t.args[idx] {
1143                                                                                                         let generic_arg = types.resolve_path(&p.path, None);
1144                                                                                                         let generic_bound = types.resolve_path(&trait_bound.path, None);
1145                                                                                                         if let Some(traits_impld) = types.crate_types.trait_impls.get(&generic_arg) {
1146                                                                                                                 for trait_impld in traits_impld {
1147                                                                                                                         if *trait_impld == generic_bound { continue 'bounds_check; }
1148                                                                                                                 }
1149                                                                                                                 eprintln!("struct {}'s generic arg {} didn't match bound {}", alias_resolved, generic_arg, generic_bound);
1150                                                                                                                 continue 'alias_impls;
1151                                                                                                         } else {
1152                                                                                                                 eprintln!("struct {}'s generic arg {} didn't match bound {}", alias_resolved, generic_arg, generic_bound);
1153                                                                                                                 continue 'alias_impls;
1154                                                                                                         }
1155                                                                                                 } else { unimplemented!(); }
1156                                                                                         } else { unimplemented!(); }
1157                                                                                 } else { unimplemented!(); }
1158                                                                         }
1159                                                                 },
1160                                                                 syn::GenericParam::Lifetime(_) => {},
1161                                                                 syn::GenericParam::Const(_) => unimplemented!(),
1162                                                         }
1163                                                 }
1164                                                 let aliased_impl = syn::ItemImpl {
1165                                                         attrs: i.attrs.clone(),
1166                                                         brace_token: syn::token::Brace(Span::call_site()),
1167                                                         defaultness: None,
1168                                                         generics: syn::Generics {
1169                                                                 lt_token: None,
1170                                                                 params: syn::punctuated::Punctuated::new(),
1171                                                                 gt_token: None,
1172                                                                 where_clause: None,
1173                                                         },
1174                                                         impl_token: syn::Token![impl](Span::call_site()),
1175                                                         items: i.items.clone(),
1176                                                         self_ty: Box::new(syn::Type::Path(syn::TypePath { qself: None, path: alias.clone() })),
1177                                                         trait_: i.trait_.clone(),
1178                                                         unsafety: None,
1179                                                 };
1180                                                 writeln_impl(w, &aliased_impl, types);
1181                                         }
1182                                 } else {
1183                                         eprintln!("Not implementing anything for {} due to it being marked not exported", ident);
1184                                 }
1185                         } else {
1186                                 eprintln!("Not implementing anything for {} due to no-resolve (probably the type isn't pub)", ident);
1187                         }
1188                 }
1189         }
1190 }
1191
1192 /// Replaces upper case charachters with underscore followed by lower case except the first
1193 /// charachter and repeated upper case characthers (which are only made lower case).
1194 fn camel_to_snake_case(camel: &str) -> String {
1195         let mut res = "".to_string();
1196         let mut last_upper = -1;
1197         for (idx, c) in camel.chars().enumerate() {
1198                 if c.is_uppercase() {
1199                         if last_upper != idx as isize - 1 { res.push('_'); }
1200                         res.push(c.to_lowercase().next().unwrap());
1201                         last_upper = idx as isize;
1202                 } else {
1203                         res.push(c);
1204                 }
1205         }
1206         res
1207 }
1208
1209
1210 /// Print a mapping of an enum. If all of the enum's fields are C-mapped in some form (or the enum
1211 /// is unitary), we generate an equivalent enum with all types replaced with their C mapped
1212 /// versions followed by conversion functions which map between the Rust version and the C mapped
1213 /// version.
1214 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) {
1215         match export_status(&e.attrs) {
1216                 ExportStatus::Export => {},
1217                 ExportStatus::NoExport|ExportStatus::TestOnly => return,
1218                 ExportStatus::NotImplementable => panic!("(C-not implementable) must only appear on traits"),
1219         }
1220
1221         if is_enum_opaque(e) {
1222                 eprintln!("Skipping enum {} as it contains non-unit fields", e.ident);
1223                 writeln_opaque(w, &e.ident, &format!("{}", e.ident), &e.generics, &e.attrs, types, extra_headers, cpp_headers);
1224                 return;
1225         }
1226         writeln_docs(w, &e.attrs, "");
1227
1228         let mut gen_types = GenericTypes::new(None);
1229         assert!(gen_types.learn_generics(&e.generics, types));
1230
1231         let mut needs_free = false;
1232         let mut constr = Vec::new();
1233
1234         writeln!(w, "#[must_use]\n#[derive(Clone)]\n#[repr(C)]\npub enum {} {{", e.ident).unwrap();
1235         for var in e.variants.iter() {
1236                 assert_eq!(export_status(&var.attrs), ExportStatus::Export); // We can't partially-export a mirrored enum
1237                 writeln_docs(w, &var.attrs, "\t");
1238                 write!(w, "\t{}", var.ident).unwrap();
1239                 writeln!(&mut constr, "#[no_mangle]\n/// Utility method to constructs a new {}-variant {}", var.ident, e.ident).unwrap();
1240                 let constr_name = camel_to_snake_case(&format!("{}", var.ident));
1241                 write!(&mut constr, "pub extern \"C\" fn {}_{}(", e.ident, constr_name).unwrap();
1242                 let mut empty_tuple_variant = false;
1243                 if let syn::Fields::Named(fields) = &var.fields {
1244                         needs_free = true;
1245                         writeln!(w, " {{").unwrap();
1246                         for (idx, field) in fields.named.iter().enumerate() {
1247                                 if export_status(&field.attrs) == ExportStatus::TestOnly { continue; }
1248                                 writeln_field_docs(w, &field.attrs, "\t\t", types, Some(&gen_types), &field.ty);
1249                                 write!(w, "\t\t{}: ", field.ident.as_ref().unwrap()).unwrap();
1250                                 write!(&mut constr, "{}{}: ", if idx != 0 { ", " } else { "" }, field.ident.as_ref().unwrap()).unwrap();
1251                                 types.write_c_type(w, &field.ty, Some(&gen_types), false);
1252                                 types.write_c_type(&mut constr, &field.ty, Some(&gen_types), false);
1253                                 writeln!(w, ",").unwrap();
1254                         }
1255                         write!(w, "\t}}").unwrap();
1256                 } else if let syn::Fields::Unnamed(fields) = &var.fields {
1257                         if fields.unnamed.len() == 1 {
1258                                 let mut empty_check = Vec::new();
1259                                 types.write_c_type(&mut empty_check, &fields.unnamed[0].ty, Some(&gen_types), false);
1260                                 if empty_check.is_empty() {
1261                                         empty_tuple_variant = true;
1262                                 }
1263                         }
1264                         if !empty_tuple_variant {
1265                                 needs_free = true;
1266                                 write!(w, "(").unwrap();
1267                                 for (idx, field) in fields.unnamed.iter().enumerate() {
1268                                         if export_status(&field.attrs) == ExportStatus::TestOnly { continue; }
1269                                         write!(&mut constr, "{}: ", ('a' as u8 + idx as u8) as char).unwrap();
1270                                         types.write_c_type(w, &field.ty, Some(&gen_types), false);
1271                                         types.write_c_type(&mut constr, &field.ty, Some(&gen_types), false);
1272                                         if idx != fields.unnamed.len() - 1 {
1273                                                 write!(w, ",").unwrap();
1274                                                 write!(&mut constr, ",").unwrap();
1275                                         }
1276                                 }
1277                                 write!(w, ")").unwrap();
1278                         }
1279                 }
1280                 if var.discriminant.is_some() { unimplemented!(); }
1281                 write!(&mut constr, ") -> {} {{\n\t{}::{}", e.ident, e.ident, var.ident).unwrap();
1282                 if let syn::Fields::Named(fields) = &var.fields {
1283                         writeln!(&mut constr, " {{").unwrap();
1284                         for field in fields.named.iter() {
1285                                 writeln!(&mut constr, "\t\t{},", field.ident.as_ref().unwrap()).unwrap();
1286                         }
1287                         writeln!(&mut constr, "\t}}").unwrap();
1288                 } else if let syn::Fields::Unnamed(fields) = &var.fields {
1289                         if !empty_tuple_variant {
1290                                 write!(&mut constr, "(").unwrap();
1291                                 for idx in 0..fields.unnamed.len() {
1292                                         write!(&mut constr, "{}, ", ('a' as u8 + idx as u8) as char).unwrap();
1293                                 }
1294                                 writeln!(&mut constr, ")").unwrap();
1295                         } else {
1296                                 writeln!(&mut constr, "").unwrap();
1297                         }
1298                 }
1299                 writeln!(&mut constr, "}}").unwrap();
1300                 writeln!(w, ",").unwrap();
1301         }
1302         writeln!(w, "}}\nuse {}::{} as native{};\nimpl {} {{", types.module_path, e.ident, e.ident, e.ident).unwrap();
1303
1304         macro_rules! write_conv {
1305                 ($fn_sig: expr, $to_c: expr, $ref: expr) => {
1306                         writeln!(w, "\t#[allow(unused)]\n\tpub(crate) fn {} {{\n\t\tmatch {} {{", $fn_sig, if $to_c { "native" } else { "self" }).unwrap();
1307                         for var in e.variants.iter() {
1308                                 write!(w, "\t\t\t{}{}::{} ", if $to_c { "native" } else { "" }, e.ident, var.ident).unwrap();
1309                                 let mut empty_tuple_variant = false;
1310                                 if let syn::Fields::Named(fields) = &var.fields {
1311                                         write!(w, "{{").unwrap();
1312                                         for field in fields.named.iter() {
1313                                                 if export_status(&field.attrs) == ExportStatus::TestOnly { continue; }
1314                                                 write!(w, "{}{}, ", if $ref { "ref " } else { "mut " }, field.ident.as_ref().unwrap()).unwrap();
1315                                         }
1316                                         write!(w, "}} ").unwrap();
1317                                 } else if let syn::Fields::Unnamed(fields) = &var.fields {
1318                                         if fields.unnamed.len() == 1 {
1319                                                 let mut empty_check = Vec::new();
1320                                                 types.write_c_type(&mut empty_check, &fields.unnamed[0].ty, Some(&gen_types), false);
1321                                                 if empty_check.is_empty() {
1322                                                         empty_tuple_variant = true;
1323                                                 }
1324                                         }
1325                                         if !empty_tuple_variant || $to_c {
1326                                                 write!(w, "(").unwrap();
1327                                                 for (idx, field) in fields.unnamed.iter().enumerate() {
1328                                                         if export_status(&field.attrs) == ExportStatus::TestOnly { continue; }
1329                                                         write!(w, "{}{}, ", if $ref { "ref " } else { "mut " }, ('a' as u8 + idx as u8) as char).unwrap();
1330                                                 }
1331                                                 write!(w, ") ").unwrap();
1332                                         }
1333                                 }
1334                                 write!(w, "=>").unwrap();
1335
1336                                 macro_rules! handle_field_a {
1337                                         ($field: expr, $field_ident: expr) => { {
1338                                                 if export_status(&$field.attrs) == ExportStatus::TestOnly { continue; }
1339                                                 let mut sink = ::std::io::sink();
1340                                                 let mut out: &mut dyn std::io::Write = if $ref { &mut sink } else { w };
1341                                                 let new_var = if $to_c {
1342                                                         types.write_to_c_conversion_new_var(&mut out, $field_ident, &$field.ty, Some(&gen_types), false)
1343                                                 } else {
1344                                                         types.write_from_c_conversion_new_var(&mut out, $field_ident, &$field.ty, Some(&gen_types))
1345                                                 };
1346                                                 if $ref || new_var {
1347                                                         if $ref {
1348                                                                 write!(w, "let mut {}_nonref = (*{}).clone();\n\t\t\t\t", $field_ident, $field_ident).unwrap();
1349                                                                 if new_var {
1350                                                                         let nonref_ident = format_ident!("{}_nonref", $field_ident);
1351                                                                         if $to_c {
1352                                                                                 types.write_to_c_conversion_new_var(w, &nonref_ident, &$field.ty, Some(&gen_types), false);
1353                                                                         } else {
1354                                                                                 types.write_from_c_conversion_new_var(w, &nonref_ident, &$field.ty, Some(&gen_types));
1355                                                                         }
1356                                                                         write!(w, "\n\t\t\t\t").unwrap();
1357                                                                 }
1358                                                         } else {
1359                                                                 write!(w, "\n\t\t\t\t").unwrap();
1360                                                         }
1361                                                 }
1362                                         } }
1363                                 }
1364                                 if let syn::Fields::Named(fields) = &var.fields {
1365                                         write!(w, " {{\n\t\t\t\t").unwrap();
1366                                         for field in fields.named.iter() {
1367                                                 handle_field_a!(field, field.ident.as_ref().unwrap());
1368                                         }
1369                                 } else if let syn::Fields::Unnamed(fields) = &var.fields {
1370                                         write!(w, " {{\n\t\t\t\t").unwrap();
1371                                         for (idx, field) in fields.unnamed.iter().enumerate() {
1372                                                 if !empty_tuple_variant {
1373                                                         handle_field_a!(field, &format_ident!("{}", ('a' as u8 + idx as u8) as char));
1374                                                 }
1375                                         }
1376                                 } else { write!(w, " ").unwrap(); }
1377
1378                                 write!(w, "{}{}::{}", if $to_c { "" } else { "native" }, e.ident, var.ident).unwrap();
1379
1380                                 macro_rules! handle_field_b {
1381                                         ($field: expr, $field_ident: expr) => { {
1382                                                 if export_status(&$field.attrs) == ExportStatus::TestOnly { continue; }
1383                                                 if $to_c {
1384                                                         types.write_to_c_conversion_inline_prefix(w, &$field.ty, Some(&gen_types), false);
1385                                                 } else {
1386                                                         types.write_from_c_conversion_prefix(w, &$field.ty, Some(&gen_types));
1387                                                 }
1388                                                 write!(w, "{}{}", $field_ident,
1389                                                         if $ref { "_nonref" } else { "" }).unwrap();
1390                                                 if $to_c {
1391                                                         types.write_to_c_conversion_inline_suffix(w, &$field.ty, Some(&gen_types), false);
1392                                                 } else {
1393                                                         types.write_from_c_conversion_suffix(w, &$field.ty, Some(&gen_types));
1394                                                 }
1395                                                 write!(w, ",").unwrap();
1396                                         } }
1397                                 }
1398
1399                                 if let syn::Fields::Named(fields) = &var.fields {
1400                                         write!(w, " {{").unwrap();
1401                                         for field in fields.named.iter() {
1402                                                 if export_status(&field.attrs) == ExportStatus::TestOnly { continue; }
1403                                                 write!(w, "\n\t\t\t\t\t{}: ", field.ident.as_ref().unwrap()).unwrap();
1404                                                 handle_field_b!(field, field.ident.as_ref().unwrap());
1405                                         }
1406                                         writeln!(w, "\n\t\t\t\t}}").unwrap();
1407                                         write!(w, "\t\t\t}}").unwrap();
1408                                 } else if let syn::Fields::Unnamed(fields) = &var.fields {
1409                                         if !empty_tuple_variant || !$to_c {
1410                                                 write!(w, " (").unwrap();
1411                                                 for (idx, field) in fields.unnamed.iter().enumerate() {
1412                                                         write!(w, "\n\t\t\t\t\t").unwrap();
1413                                                         handle_field_b!(field, &format_ident!("{}", ('a' as u8 + idx as u8) as char));
1414                                                 }
1415                                                 writeln!(w, "\n\t\t\t\t)").unwrap();
1416                                         }
1417                                         write!(w, "\t\t\t}}").unwrap();
1418                                 }
1419                                 writeln!(w, ",").unwrap();
1420                         }
1421                         writeln!(w, "\t\t}}\n\t}}").unwrap();
1422                 }
1423         }
1424
1425         write_conv!(format!("to_native(&self) -> native{}", e.ident), false, true);
1426         write_conv!(format!("into_native(self) -> native{}", e.ident), false, false);
1427         write_conv!(format!("from_native(native: &native{}) -> Self", e.ident), true, true);
1428         write_conv!(format!("native_into(native: native{}) -> Self", e.ident), true, false);
1429         writeln!(w, "}}").unwrap();
1430
1431         if needs_free {
1432                 writeln!(w, "/// Frees any resources used by the {}", e.ident).unwrap();
1433                 writeln!(w, "#[no_mangle]\npub extern \"C\" fn {}_free(this_ptr: {}) {{ }}", e.ident, e.ident).unwrap();
1434         }
1435         writeln!(w, "/// Creates a copy of the {}", e.ident).unwrap();
1436         writeln!(w, "#[no_mangle]").unwrap();
1437         writeln!(w, "pub extern \"C\" fn {}_clone(orig: &{}) -> {} {{", e.ident, e.ident, e.ident).unwrap();
1438         writeln!(w, "\torig.clone()").unwrap();
1439         writeln!(w, "}}").unwrap();
1440         w.write_all(&constr).unwrap();
1441         write_cpp_wrapper(cpp_headers, &format!("{}", e.ident), needs_free, None);
1442 }
1443
1444 fn writeln_fn<'a, 'b, W: std::io::Write>(w: &mut W, f: &'a syn::ItemFn, types: &mut TypeResolver<'b, 'a>) {
1445         match export_status(&f.attrs) {
1446                 ExportStatus::Export => {},
1447                 ExportStatus::NoExport|ExportStatus::TestOnly => return,
1448                 ExportStatus::NotImplementable => panic!("(C-not implementable) must only appear on traits"),
1449         }
1450         let mut gen_types = GenericTypes::new(None);
1451         if !gen_types.learn_generics(&f.sig.generics, types) { return; }
1452
1453         writeln_fn_docs(w, &f.attrs, "", types, Some(&gen_types), f.sig.inputs.iter(), &f.sig.output);
1454
1455         write!(w, "#[no_mangle]\npub extern \"C\" fn {}(", f.sig.ident).unwrap();
1456         write_method_params(w, &f.sig, "", types, Some(&gen_types), false, true);
1457         write!(w, " {{\n\t").unwrap();
1458         write_method_var_decl_body(w, &f.sig, "", types, Some(&gen_types), false);
1459         write!(w, "{}::{}(", types.module_path, f.sig.ident).unwrap();
1460         write_method_call_params(w, &f.sig, "", types, Some(&gen_types), "", false);
1461         writeln!(w, "\n}}\n").unwrap();
1462 }
1463
1464 // ********************************
1465 // *** File/Crate Walking Logic ***
1466 // ********************************
1467
1468 fn convert_priv_mod<'a, 'b: 'a, W: std::io::Write>(w: &mut W, libast: &'b FullLibraryAST, crate_types: &CrateTypes<'b>, out_dir: &str, mod_path: &str, module: &'b syn::ItemMod) {
1469         // We want to ignore all items declared in this module (as they are not pub), but we still need
1470         // to give the ImportResolver any use statements, so we copy them here.
1471         let mut use_items = Vec::new();
1472         for item in module.content.as_ref().unwrap().1.iter() {
1473                 if let syn::Item::Use(_) = item {
1474                         use_items.push(item);
1475                 }
1476         }
1477         let import_resolver = ImportResolver::from_borrowed_items(mod_path.splitn(2, "::").next().unwrap(), &libast.dependencies, mod_path, &use_items);
1478         let mut types = TypeResolver::new(mod_path, import_resolver, crate_types);
1479
1480         writeln!(w, "mod {} {{\n{}", module.ident, DEFAULT_IMPORTS).unwrap();
1481         for item in module.content.as_ref().unwrap().1.iter() {
1482                 match item {
1483                         syn::Item::Mod(m) => convert_priv_mod(w, libast, crate_types, out_dir, &format!("{}::{}", mod_path, module.ident), m),
1484                         syn::Item::Impl(i) => {
1485                                 if let &syn::Type::Path(ref p) = &*i.self_ty {
1486                                         if p.path.get_ident().is_some() {
1487                                                 writeln_impl(w, i, &mut types);
1488                                         }
1489                                 }
1490                         },
1491                         _ => {},
1492                 }
1493         }
1494         writeln!(w, "}}").unwrap();
1495 }
1496
1497 /// Do the Real Work of mapping an original file to C-callable wrappers. Creates a new file at
1498 /// `out_path` and fills it with wrapper structs/functions to allow calling the things in the AST
1499 /// at `module` from C.
1500 fn convert_file<'a, 'b>(libast: &'a FullLibraryAST, crate_types: &CrateTypes<'a>, out_dir: &str, header_file: &mut File, cpp_header_file: &mut File) {
1501         for (module, astmod) in libast.modules.iter() {
1502                 let orig_crate = module.splitn(2, "::").next().unwrap();
1503                 let ASTModule { ref attrs, ref items, ref submods } = astmod;
1504                 assert_eq!(export_status(&attrs), ExportStatus::Export);
1505
1506                 let new_file_path = if submods.is_empty() {
1507                         format!("{}/{}.rs", out_dir, module.replace("::", "/"))
1508                 } else if module != "" {
1509                         format!("{}/{}/mod.rs", out_dir, module.replace("::", "/"))
1510                 } else {
1511                         format!("{}/lib.rs", out_dir)
1512                 };
1513                 let _ = std::fs::create_dir((&new_file_path.as_ref() as &std::path::Path).parent().unwrap());
1514                 let mut out = std::fs::OpenOptions::new().write(true).create(true).truncate(true)
1515                         .open(new_file_path).expect("Unable to open new src file");
1516
1517                 writeln!(out, "// This file is Copyright its original authors, visible in version control").unwrap();
1518                 writeln!(out, "// history and in the source files from which this was generated.").unwrap();
1519                 writeln!(out, "//").unwrap();
1520                 writeln!(out, "// This file is licensed under the license available in the LICENSE or LICENSE.md").unwrap();
1521                 writeln!(out, "// file in the root of this repository or, if no such file exists, the same").unwrap();
1522                 writeln!(out, "// license as that which applies to the original source files from which this").unwrap();
1523                 writeln!(out, "// source was automatically generated.").unwrap();
1524                 writeln!(out, "").unwrap();
1525
1526                 writeln_docs(&mut out, &attrs, "");
1527
1528                 if module == "" {
1529                         // Special-case the top-level lib.rs with various lint allows and a pointer to the c_types
1530                         // and bitcoin hand-written modules.
1531                         writeln!(out, "//! C Bindings").unwrap();
1532                         writeln!(out, "#![allow(unknown_lints)]").unwrap();
1533                         writeln!(out, "#![allow(non_camel_case_types)]").unwrap();
1534                         writeln!(out, "#![allow(non_snake_case)]").unwrap();
1535                         writeln!(out, "#![allow(unused_imports)]").unwrap();
1536                         writeln!(out, "#![allow(unused_variables)]").unwrap();
1537                         writeln!(out, "#![allow(unused_mut)]").unwrap();
1538                         writeln!(out, "#![allow(unused_parens)]").unwrap();
1539                         writeln!(out, "#![allow(unused_unsafe)]").unwrap();
1540                         writeln!(out, "#![allow(unused_braces)]").unwrap();
1541                         // TODO: We need to map deny(missing_docs) in the source crate(s)
1542                         //writeln!(out, "#![deny(missing_docs)]").unwrap();
1543                         writeln!(out, "pub mod version;").unwrap();
1544                         writeln!(out, "pub mod c_types;").unwrap();
1545                         writeln!(out, "pub mod bitcoin;").unwrap();
1546                 } else {
1547                         writeln!(out, "{}", DEFAULT_IMPORTS).unwrap();
1548                 }
1549
1550                 for m in submods {
1551                         writeln!(out, "pub mod {};", m).unwrap();
1552                 }
1553
1554                 eprintln!("Converting {} entries...", module);
1555
1556                 let import_resolver = ImportResolver::new(orig_crate, &libast.dependencies, module, items);
1557                 let mut type_resolver = TypeResolver::new(module, import_resolver, crate_types);
1558
1559                 for item in items.iter() {
1560                         match item {
1561                                 syn::Item::Use(_) => {}, // Handled above
1562                                 syn::Item::Static(_) => {},
1563                                 syn::Item::Enum(e) => {
1564                                         if let syn::Visibility::Public(_) = e.vis {
1565                                                 writeln_enum(&mut out, &e, &mut type_resolver, header_file, cpp_header_file);
1566                                         }
1567                                 },
1568                                 syn::Item::Impl(i) => {
1569                                         writeln_impl(&mut out, &i, &mut type_resolver);
1570                                 },
1571                                 syn::Item::Struct(s) => {
1572                                         if let syn::Visibility::Public(_) = s.vis {
1573                                                 writeln_struct(&mut out, &s, &mut type_resolver, header_file, cpp_header_file);
1574                                         }
1575                                 },
1576                                 syn::Item::Trait(t) => {
1577                                         if let syn::Visibility::Public(_) = t.vis {
1578                                                 writeln_trait(&mut out, &t, &mut type_resolver, header_file, cpp_header_file);
1579                                         }
1580                                 },
1581                                 syn::Item::Mod(m) => {
1582                                         convert_priv_mod(&mut out, libast, crate_types, out_dir, &format!("{}::{}", module, m.ident), m);
1583                                 },
1584                                 syn::Item::Const(c) => {
1585                                         // Re-export any primitive-type constants.
1586                                         if let syn::Visibility::Public(_) = c.vis {
1587                                                 if let syn::Type::Path(p) = &*c.ty {
1588                                                         let resolved_path = type_resolver.resolve_path(&p.path, None);
1589                                                         if type_resolver.is_primitive(&resolved_path) {
1590                                                                 writeln_field_docs(&mut out, &c.attrs, "", &mut type_resolver, None, &*c.ty);
1591                                                                 writeln!(out, "\n#[no_mangle]").unwrap();
1592                                                                 writeln!(out, "pub static {}: {} = {}::{};", c.ident, resolved_path, module, c.ident).unwrap();
1593                                                         }
1594                                                 }
1595                                         }
1596                                 },
1597                                 syn::Item::Type(t) => {
1598                                         if let syn::Visibility::Public(_) = t.vis {
1599                                                 match export_status(&t.attrs) {
1600                                                         ExportStatus::Export => {},
1601                                                         ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1602                                                         ExportStatus::NotImplementable => panic!("(C-not implementable) must only appear on traits"),
1603                                                 }
1604
1605                                                 let mut process_alias = true;
1606                                                 for tok in t.generics.params.iter() {
1607                                                         if let syn::GenericParam::Lifetime(_) = tok {}
1608                                                         else { process_alias = false; }
1609                                                 }
1610                                                 if process_alias {
1611                                                         match &*t.ty {
1612                                                                 syn::Type::Path(_) =>
1613                                                                         writeln_opaque(&mut out, &t.ident, &format!("{}", t.ident), &t.generics, &t.attrs, &type_resolver, header_file, cpp_header_file),
1614                                                                 _ => {}
1615                                                         }
1616                                                 }
1617                                         }
1618                                 },
1619                                 syn::Item::Fn(f) => {
1620                                         if let syn::Visibility::Public(_) = f.vis {
1621                                                 writeln_fn(&mut out, &f, &mut type_resolver);
1622                                         }
1623                                 },
1624                                 syn::Item::Macro(_) => {},
1625                                 syn::Item::Verbatim(_) => {},
1626                                 syn::Item::ExternCrate(_) => {},
1627                                 _ => unimplemented!(),
1628                         }
1629                 }
1630
1631                 out.flush().unwrap();
1632         }
1633 }
1634
1635 fn walk_private_mod<'a>(ast_storage: &'a FullLibraryAST, orig_crate: &str, module: String, items: &'a syn::ItemMod, crate_types: &mut CrateTypes<'a>) {
1636         let import_resolver = ImportResolver::new(orig_crate, &ast_storage.dependencies, &module, &items.content.as_ref().unwrap().1);
1637         for item in items.content.as_ref().unwrap().1.iter() {
1638                 match item {
1639                         syn::Item::Mod(m) => walk_private_mod(ast_storage, orig_crate, format!("{}::{}", module, m.ident), m, crate_types),
1640                         syn::Item::Impl(i) => {
1641                                 if let &syn::Type::Path(ref p) = &*i.self_ty {
1642                                         if let Some(trait_path) = i.trait_.as_ref() {
1643                                                 if let Some(tp) = import_resolver.maybe_resolve_path(&trait_path.1, None) {
1644                                                         if let Some(sp) = import_resolver.maybe_resolve_path(&p.path, None) {
1645                                                                 match crate_types.trait_impls.entry(sp) {
1646                                                                         hash_map::Entry::Occupied(mut e) => { e.get_mut().push(tp); },
1647                                                                         hash_map::Entry::Vacant(e) => { e.insert(vec![tp]); },
1648                                                                 }
1649                                                         }
1650                                                 }
1651                                         }
1652                                 }
1653                         },
1654                         _ => {},
1655                 }
1656         }
1657 }
1658
1659 /// Walk the FullLibraryAST, deciding how things will be mapped and adding tracking to CrateTypes.
1660 fn walk_ast<'a>(ast_storage: &'a FullLibraryAST, crate_types: &mut CrateTypes<'a>) {
1661         for (module, astmod) in ast_storage.modules.iter() {
1662                 let ASTModule { ref attrs, ref items, submods: _ } = astmod;
1663                 assert_eq!(export_status(&attrs), ExportStatus::Export);
1664                 let orig_crate = module.splitn(2, "::").next().unwrap();
1665                 let import_resolver = ImportResolver::new(orig_crate, &ast_storage.dependencies, module, items);
1666
1667                 for item in items.iter() {
1668                         match item {
1669                                 syn::Item::Struct(s) => {
1670                                         if let syn::Visibility::Public(_) = s.vis {
1671                                                 match export_status(&s.attrs) {
1672                                                         ExportStatus::Export => {},
1673                                                         ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1674                                                         ExportStatus::NotImplementable => panic!("(C-not implementable) must only appear on traits"),
1675                                                 }
1676                                                 let struct_path = format!("{}::{}", module, s.ident);
1677                                                 crate_types.opaques.insert(struct_path, &s.ident);
1678                                         }
1679                                 },
1680                                 syn::Item::Trait(t) => {
1681                                         if let syn::Visibility::Public(_) = t.vis {
1682                                                 match export_status(&t.attrs) {
1683                                                         ExportStatus::Export|ExportStatus::NotImplementable => {},
1684                                                         ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1685                                                 }
1686                                                 let trait_path = format!("{}::{}", module, t.ident);
1687                                                 walk_supertraits!(t, None, (
1688                                                         ("Clone", _) => {
1689                                                                 crate_types.set_clonable("crate::".to_owned() + &trait_path);
1690                                                         },
1691                                                         (_, _) => {}
1692                                                 ) );
1693                                                 crate_types.traits.insert(trait_path, &t);
1694                                         }
1695                                 },
1696                                 syn::Item::Type(t) => {
1697                                         if let syn::Visibility::Public(_) = t.vis {
1698                                                 match export_status(&t.attrs) {
1699                                                         ExportStatus::Export => {},
1700                                                         ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1701                                                         ExportStatus::NotImplementable => panic!("(C-not implementable) must only appear on traits"),
1702                                                 }
1703                                                 let type_path = format!("{}::{}", module, t.ident);
1704                                                 let mut process_alias = true;
1705                                                 for tok in t.generics.params.iter() {
1706                                                         if let syn::GenericParam::Lifetime(_) = tok {}
1707                                                         else { process_alias = false; }
1708                                                 }
1709                                                 if process_alias {
1710                                                         match &*t.ty {
1711                                                                 syn::Type::Path(p) => {
1712                                                                         let t_ident = &t.ident;
1713
1714                                                                         // If its a path with no generics, assume we don't map the aliased type and map it opaque
1715                                                                         let path_obj = parse_quote!(#t_ident);
1716                                                                         let args_obj = p.path.segments.last().unwrap().arguments.clone();
1717                                                                         match crate_types.reverse_alias_map.entry(import_resolver.maybe_resolve_path(&p.path, None).unwrap()) {
1718                                                                                 hash_map::Entry::Occupied(mut e) => { e.get_mut().push((path_obj, args_obj)); },
1719                                                                                 hash_map::Entry::Vacant(e) => { e.insert(vec![(path_obj, args_obj)]); },
1720                                                                         }
1721
1722                                                                         crate_types.opaques.insert(type_path, t_ident);
1723                                                                 },
1724                                                                 _ => {
1725                                                                         crate_types.type_aliases.insert(type_path, import_resolver.resolve_imported_refs((*t.ty).clone()));
1726                                                                 }
1727                                                         }
1728                                                 }
1729                                         }
1730                                 },
1731                                 syn::Item::Enum(e) if is_enum_opaque(e) => {
1732                                         if let syn::Visibility::Public(_) = e.vis {
1733                                                 match export_status(&e.attrs) {
1734                                                         ExportStatus::Export => {},
1735                                                         ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1736                                                         ExportStatus::NotImplementable => panic!("(C-not implementable) must only appear on traits"),
1737                                                 }
1738                                                 let enum_path = format!("{}::{}", module, e.ident);
1739                                                 crate_types.opaques.insert(enum_path, &e.ident);
1740                                         }
1741                                 },
1742                                 syn::Item::Enum(e) => {
1743                                         if let syn::Visibility::Public(_) = e.vis {
1744                                                 match export_status(&e.attrs) {
1745                                                         ExportStatus::Export => {},
1746                                                         ExportStatus::NoExport|ExportStatus::TestOnly => continue,
1747                                                         ExportStatus::NotImplementable => panic!("(C-not implementable) must only appear on traits"),
1748                                                 }
1749                                                 let enum_path = format!("{}::{}", module, e.ident);
1750                                                 crate_types.mirrored_enums.insert(enum_path, &e);
1751                                         }
1752                                 },
1753                                 syn::Item::Impl(i) => {
1754                                         if let &syn::Type::Path(ref p) = &*i.self_ty {
1755                                                 if let Some(trait_path) = i.trait_.as_ref() {
1756                                                         if path_matches_nongeneric(&trait_path.1, &["core", "clone", "Clone"]) {
1757                                                                 if let Some(full_path) = import_resolver.maybe_resolve_path(&p.path, None) {
1758                                                                         crate_types.set_clonable("crate::".to_owned() + &full_path);
1759                                                                 }
1760                                                         }
1761                                                         if let Some(tp) = import_resolver.maybe_resolve_path(&trait_path.1, None) {
1762                                                                 if let Some(sp) = import_resolver.maybe_resolve_path(&p.path, None) {
1763                                                                         match crate_types.trait_impls.entry(sp) {
1764                                                                                 hash_map::Entry::Occupied(mut e) => { e.get_mut().push(tp); },
1765                                                                                 hash_map::Entry::Vacant(e) => { e.insert(vec![tp]); },
1766                                                                         }
1767                                                                 }
1768                                                         }
1769                                                 }
1770                                         }
1771                                 },
1772                                 syn::Item::Mod(m) => walk_private_mod(ast_storage, orig_crate, format!("{}::{}", module, m.ident), m, crate_types),
1773                                 _ => {},
1774                         }
1775                 }
1776         }
1777 }
1778
1779 fn main() {
1780         let args: Vec<String> = env::args().collect();
1781         if args.len() != 5 {
1782                 eprintln!("Usage: target/dir derived_templates.rs extra/includes.h extra/cpp/includes.hpp");
1783                 process::exit(1);
1784         }
1785
1786         let mut derived_templates = std::fs::OpenOptions::new().write(true).create(true).truncate(true)
1787                 .open(&args[2]).expect("Unable to open new header file");
1788         let mut header_file = std::fs::OpenOptions::new().write(true).create(true).truncate(true)
1789                 .open(&args[3]).expect("Unable to open new header file");
1790         let mut cpp_header_file = std::fs::OpenOptions::new().write(true).create(true).truncate(true)
1791                 .open(&args[4]).expect("Unable to open new header file");
1792
1793         writeln!(header_file, "#if defined(__GNUC__)").unwrap();
1794         writeln!(header_file, "#define MUST_USE_STRUCT __attribute__((warn_unused))").unwrap();
1795         writeln!(header_file, "#define MUST_USE_RES __attribute__((warn_unused_result))").unwrap();
1796         writeln!(header_file, "#else").unwrap();
1797         writeln!(header_file, "#define MUST_USE_STRUCT").unwrap();
1798         writeln!(header_file, "#define MUST_USE_RES").unwrap();
1799         writeln!(header_file, "#endif").unwrap();
1800         writeln!(header_file, "#if defined(__clang__)").unwrap();
1801         writeln!(header_file, "#define NONNULL_PTR _Nonnull").unwrap();
1802         writeln!(header_file, "#else").unwrap();
1803         writeln!(header_file, "#define NONNULL_PTR").unwrap();
1804         writeln!(header_file, "#endif").unwrap();
1805         writeln!(cpp_header_file, "#include <string.h>\nnamespace LDK {{").unwrap();
1806
1807         // First parse the full crate's ASTs, caching them so that we can hold references to the AST
1808         // objects in other datastructures:
1809         let mut lib_src = String::new();
1810         std::io::stdin().lock().read_to_string(&mut lib_src).unwrap();
1811         let lib_syntax = syn::parse_file(&lib_src).expect("Unable to parse file");
1812         let libast = FullLibraryAST::load_lib(lib_syntax);
1813
1814         // ...then walk the ASTs tracking what types we will map, and how, so that we can resolve them
1815         // when parsing other file ASTs...
1816         let mut libtypes = CrateTypes::new(&mut derived_templates, &libast);
1817         walk_ast(&libast, &mut libtypes);
1818
1819         // ... finally, do the actual file conversion/mapping, writing out types as we go.
1820         convert_file(&libast, &libtypes, &args[1], &mut header_file, &mut cpp_header_file);
1821
1822         // For container templates which we created while walking the crate, make sure we add C++
1823         // mapped types so that C++ users can utilize the auto-destructors available.
1824         for (ty, has_destructor) in libtypes.templates_defined.borrow().iter() {
1825                 write_cpp_wrapper(&mut cpp_header_file, ty, *has_destructor, None);
1826         }
1827         writeln!(cpp_header_file, "}}").unwrap();
1828
1829         header_file.flush().unwrap();
1830         cpp_header_file.flush().unwrap();
1831         derived_templates.flush().unwrap();
1832 }