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

   1 use std::collections::{HashMap, HashSet};
   2 use std::fs::File;
   3 use std::io::Write;
   4 use std::hash;
   5
   6 use crate::blocks::*;
   7
   8 use proc_macro2::{TokenTree, Span};
   9
  10 // The following utils are used purely to build our known types maps - they break down all the
  11 // types we need to resolve to include the given object, and no more.
  12
  13 pub fn first_seg_self<'a>(t: &'a syn::Type) -> Option<impl Iterator<Item=&syn::PathSegment> + 'a> {
  14         match t {
  15                 syn::Type::Path(p) => {
  16                         if p.qself.is_some() || p.path.leading_colon.is_some() {
  17                                 return None;
  18                         }
  19                         let mut segs = p.path.segments.iter();
  20                         let ty = segs.next().unwrap();
  21                         if !ty.arguments.is_empty() { return None; }
  22                         if format!("{}", ty.ident) == "Self" {
  23                                 Some(segs)
  24                         } else { None }
  25                 },
  26                 _ => None,
  27         }
  28 }
  29
  30 pub fn get_single_remaining_path_seg<'a, I: Iterator<Item=&'a syn::PathSegment>>(segs: &mut I) -> Option<&'a syn::Ident> {
  31         if let Some(ty) = segs.next() {
  32                 if !ty.arguments.is_empty() { unimplemented!(); }
  33                 if segs.next().is_some() { return None; }
  34                 Some(&ty.ident)
  35         } else { None }
  36 }
  37
  38 pub fn single_ident_generic_path_to_ident(p: &syn::Path) -> Option<&syn::Ident> {
  39         if p.segments.len() == 1 {
  40                 Some(&p.segments.iter().next().unwrap().ident)
  41         } else { None }
  42 }
  43
  44 pub fn path_matches_nongeneric(p: &syn::Path, exp: &[&str]) -> bool {
  45         if p.segments.len() != exp.len() { return false; }
  46         for (seg, e) in p.segments.iter().zip(exp.iter()) {
  47                 if seg.arguments != syn::PathArguments::None { return false; }
  48                 if &format!("{}", seg.ident) != *e { return false; }
  49         }
  50         true
  51 }
  52
  53 #[derive(Debug, PartialEq)]
  54 pub enum ExportStatus {
  55         Export,
  56         NoExport,
  57         TestOnly,
  58 }
  59 /// Gets the ExportStatus of an object (struct, fn, etc) given its attributes.
  60 pub fn export_status(attrs: &[syn::Attribute]) -> ExportStatus {
  61         for attr in attrs.iter() {
  62                 let tokens_clone = attr.tokens.clone();
  63                 let mut token_iter = tokens_clone.into_iter();
  64                 if let Some(token) = token_iter.next() {
  65                         match token {
  66                                 TokenTree::Punct(c) if c.as_char() == '=' => {
  67                                         // Really not sure where syn gets '=' from here -
  68                                         // it somehow represents '///' or '//!'
  69                                 },
  70                                 TokenTree::Group(g) => {
  71                                         if format!("{}", single_ident_generic_path_to_ident(&attr.path).unwrap()) == "cfg" {
  72                                                 let mut iter = g.stream().into_iter();
  73                                                 if let TokenTree::Ident(i) = iter.next().unwrap() {
  74                                                         if i == "any" {
  75                                                                 // #[cfg(any(test, feature = ""))]
  76                                                                 if let TokenTree::Group(g) = iter.next().unwrap() {
  77                                                                         if let TokenTree::Ident(i) = g.stream().into_iter().next().unwrap() {
  78                                                                                 if i == "test" || i == "feature" {
  79                                                                                         // If its cfg(feature(...)) we assume its test-only
  80                                                                                         return ExportStatus::TestOnly;
  81                                                                                 }
  82                                                                         }
  83                                                                 }
  84                                                         } else if i == "test" || i == "feature" {
  85                                                                 // If its cfg(feature(...)) we assume its test-only
  86                                                                 return ExportStatus::TestOnly;
  87                                                         }
  88                                                 }
  89                                         }
  90                                         continue; // eg #[derive()]
  91                                 },
  92                                 _ => unimplemented!(),
  93                         }
  94                 } else { continue; }
  95                 match token_iter.next().unwrap() {
  96                         TokenTree::Literal(lit) => {
  97                                 let line = format!("{}", lit);
  98                                 if line.contains("(C-not exported)") {
  99                                         return ExportStatus::NoExport;
 100                                 }
 101                         },
 102                         _ => unimplemented!(),
 103                 }
 104         }
 105         ExportStatus::Export
 106 }
 107
 108 pub fn assert_simple_bound(bound: &syn::TraitBound) {
 109         if bound.paren_token.is_some() || bound.lifetimes.is_some() { unimplemented!(); }
 110         if let syn::TraitBoundModifier::Maybe(_) = bound.modifier { unimplemented!(); }
 111 }
 112
 113 /// Returns true if the enum will be mapped as an opaue (ie struct with a pointer to the underlying
 114 /// type), otherwise it is mapped into a transparent, C-compatible version of itself.
 115 pub fn is_enum_opaque(e: &syn::ItemEnum) -> bool {
 116         for var in e.variants.iter() {
 117                 if let syn::Fields::Unit = var.fields {
 118                 } else if let syn::Fields::Named(fields) = &var.fields {
 119                         for field in fields.named.iter() {
 120                                 match export_status(&field.attrs) {
 121                                         ExportStatus::Export|ExportStatus::TestOnly => {},
 122                                         ExportStatus::NoExport => return true,
 123                                 }
 124                         }
 125                 } else {
 126                         return true;
 127                 }
 128         }
 129         false
 130 }
 131
 132 /// A stack of sets of generic resolutions.
 133 ///
 134 /// This tracks the template parameters for a function, struct, or trait, allowing resolution into
 135 /// a concrete type. By pushing a new context onto the stack, this can track a function's template
 136 /// parameters inside of a generic struct or trait.
 137 ///
 138 /// It maps both direct types as well as Deref<Target = X>, mapping them via the provided
 139 /// TypeResolver's resolve_path function (ie traits map to the concrete jump table, structs to the
 140 /// concrete C container struct, etc).
 141 pub struct GenericTypes<'a> {
 142         typed_generics: Vec<HashMap<&'a syn::Ident, (String, Option<&'a syn::Path>)>>,
 143 }
 144 impl<'a> GenericTypes<'a> {
 145         pub fn new() -> Self {
 146                 Self { typed_generics: vec![HashMap::new()], }
 147         }
 148
 149         /// push a new context onto the stack, allowing for a new set of generics to be learned which
 150         /// will override any lower contexts, but which will still fall back to resoltion via lower
 151         /// contexts.
 152         pub fn push_ctx(&mut self) {
 153                 self.typed_generics.push(HashMap::new());
 154         }
 155         /// pop the latest context off the stack.
 156         pub fn pop_ctx(&mut self) {
 157                 self.typed_generics.pop();
 158         }
 159
 160         /// Learn the generics in generics in the current context, given a TypeResolver.
 161         pub fn learn_generics<'b, 'c>(&mut self, generics: &'a syn::Generics, types: &'b TypeResolver<'a, 'c>) -> bool {
 162                 // First learn simple generics...
 163                 for generic in generics.params.iter() {
 164                         match generic {
 165                                 syn::GenericParam::Type(type_param) => {
 166                                         let mut non_lifetimes_processed = false;
 167                                         for bound in type_param.bounds.iter() {
 168                                                 if let syn::TypeParamBound::Trait(trait_bound) = bound {
 169                                                         if let Some(ident) = single_ident_generic_path_to_ident(&trait_bound.path) {
 170                                                                 match &format!("{}", ident) as &str { "Send" => continue, "Sync" => continue, _ => {} }
 171                                                         }
 172                                                         if path_matches_nongeneric(&trait_bound.path, &["core", "clone", "Clone"]) { continue; }
 173
 174                                                         assert_simple_bound(&trait_bound);
 175                                                         if let Some(mut path) = types.maybe_resolve_path(&trait_bound.path, None) {
 176                                                                 if types.skip_path(&path) { continue; }
 177                                                                 if non_lifetimes_processed { return false; }
 178                                                                 non_lifetimes_processed = true;
 179                                                                 let new_ident = if path != "std::ops::Deref" {
 180                                                                         path = "crate::".to_string() + &path;
 181                                                                         Some(&trait_bound.path)
 182                                                                 } else { None };
 183                                                                 self.typed_generics.last_mut().unwrap().insert(&type_param.ident, (path, new_ident));
 184                                                         } else { return false; }
 185                                                 }
 186                                         }
 187                                 },
 188                                 _ => {},
 189                         }
 190                 }
 191                 // Then find generics where we are required to pass a Deref<Target=X> and pretend its just X.
 192                 if let Some(wh) = &generics.where_clause {
 193                         for pred in wh.predicates.iter() {
 194                                 if let syn::WherePredicate::Type(t) = pred {
 195                                         if let syn::Type::Path(p) = &t.bounded_ty {
 196                                                 if p.qself.is_some() { return false; }
 197                                                 if p.path.leading_colon.is_some() { return false; }
 198                                                 let mut p_iter = p.path.segments.iter();
 199                                                 if let Some(gen) = self.typed_generics.last_mut().unwrap().get_mut(&p_iter.next().unwrap().ident) {
 200                                                         if gen.0 != "std::ops::Deref" { return false; }
 201                                                         if &format!("{}", p_iter.next().unwrap().ident) != "Target" { return false; }
 202
 203                                                         let mut non_lifetimes_processed = false;
 204                                                         for bound in t.bounds.iter() {
 205                                                                 if let syn::TypeParamBound::Trait(trait_bound) = bound {
 206                                                                         if non_lifetimes_processed { return false; }
 207                                                                         non_lifetimes_processed = true;
 208                                                                         assert_simple_bound(&trait_bound);
 209                                                                         *gen = ("crate::".to_string() + &types.resolve_path(&trait_bound.path, None),
 210                                                                                 Some(&trait_bound.path));
 211                                                                 }
 212                                                         }
 213                                                 } else { return false; }
 214                                         } else { return false; }
 215                                 }
 216                         }
 217                 }
 218                 for (_, (_, ident)) in self.typed_generics.last().unwrap().iter() {
 219                         if ident.is_none() { return false; }
 220                 }
 221                 true
 222         }
 223
 224         /// Learn the associated types from the trait in the current context.
 225         pub fn learn_associated_types<'b, 'c>(&mut self, t: &'a syn::ItemTrait, types: &'b TypeResolver<'a, 'c>) {
 226                 for item in t.items.iter() {
 227                         match item {
 228                                 &syn::TraitItem::Type(ref t) => {
 229                                         if t.default.is_some() || t.generics.lt_token.is_some() { unimplemented!(); }
 230                                         let mut bounds_iter = t.bounds.iter();
 231                                         match bounds_iter.next().unwrap() {
 232                                                 syn::TypeParamBound::Trait(tr) => {
 233                                                         assert_simple_bound(&tr);
 234                                                         if let Some(mut path) = types.maybe_resolve_path(&tr.path, None) {
 235                                                                 if types.skip_path(&path) { continue; }
 236                                                                 // In general we handle Deref<Target=X> as if it were just X (and
 237                                                                 // implement Deref<Target=Self> for relevant types). We don't
 238                                                                 // bother to implement it for associated types, however, so we just
 239                                                                 // ignore such bounds.
 240                                                                 let new_ident = if path != "std::ops::Deref" {
 241                                                                         path = "crate::".to_string() + &path;
 242                                                                         Some(&tr.path)
 243                                                                 } else { None };
 244                                                                 self.typed_generics.last_mut().unwrap().insert(&t.ident, (path, new_ident));
 245                                                         } else { unimplemented!(); }
 246                                                 },
 247                                                 _ => unimplemented!(),
 248                                         }
 249                                         if bounds_iter.next().is_some() { unimplemented!(); }
 250                                 },
 251                                 _ => {},
 252                         }
 253                 }
 254         }
 255
 256         /// Attempt to resolve an Ident as a generic parameter and return the full path.
 257         pub fn maybe_resolve_ident<'b>(&'b self, ident: &syn::Ident) -> Option<&'b String> {
 258                 for gen in self.typed_generics.iter().rev() {
 259                         if let Some(res) = gen.get(ident).map(|(a, _)| a) {
 260                                 return Some(res);
 261                         }
 262                 }
 263                 None
 264         }
 265         /// Attempt to resolve a Path as a generic parameter and return the full path. as both a string
 266         /// and syn::Path.
 267         pub fn maybe_resolve_path<'b>(&'b self, path: &syn::Path) -> Option<(&'b String, &'a syn::Path)> {
 268                 if let Some(ident) = path.get_ident() {
 269                         for gen in self.typed_generics.iter().rev() {
 270                                 if let Some(res) = gen.get(ident).map(|(a, b)| (a, b.unwrap())) {
 271                                         return Some(res);
 272                                 }
 273                         }
 274                 } else {
 275                         // Associated types are usually specified as "Self::Generic", so we check for that
 276                         // explicitly here.
 277                         let mut it = path.segments.iter();
 278                         if path.segments.len() == 2 && format!("{}", it.next().unwrap().ident) == "Self" {
 279                                 let ident = &it.next().unwrap().ident;
 280                                 for gen in self.typed_generics.iter().rev() {
 281                                         if let Some(res) = gen.get(ident).map(|(a, b)| (a, b.unwrap())) {
 282                                                 return Some(res);
 283                                         }
 284                                 }
 285                         }
 286                 }
 287                 None
 288         }
 289 }
 290
 291 #[derive(Clone, PartialEq)]
 292 // The type of declaration and the object itself
 293 pub enum DeclType<'a> {
 294         MirroredEnum,
 295         Trait(&'a syn::ItemTrait),
 296         StructImported,
 297         StructIgnored,
 298         EnumIgnored,
 299 }
 300
 301 pub struct ImportResolver<'mod_lifetime, 'crate_lft: 'mod_lifetime> {
 302         module_path: &'mod_lifetime str,
 303         imports: HashMap<syn::Ident, (String, syn::Path)>,
 304         declared: HashMap<syn::Ident, DeclType<'crate_lft>>,
 305         priv_modules: HashSet<syn::Ident>,
 306 }
 307 impl<'mod_lifetime, 'crate_lft: 'mod_lifetime> ImportResolver<'mod_lifetime, 'crate_lft> {
 308         fn process_use_intern(imports: &mut HashMap<syn::Ident, (String, syn::Path)>, u: &syn::UseTree, partial_path: &str, mut path: syn::punctuated::Punctuated<syn::PathSegment, syn::token::Colon2>) {
 309                 match u {
 310                         syn::UseTree::Path(p) => {
 311                                 let new_path = format!("{}{}::", partial_path, p.ident);
 312                                 path.push(syn::PathSegment { ident: p.ident.clone(), arguments: syn::PathArguments::None });
 313                                 Self::process_use_intern(imports, &p.tree, &new_path, path);
 314                         },
 315                         syn::UseTree::Name(n) => {
 316                                 let full_path = format!("{}{}", partial_path, n.ident);
 317                                 path.push(syn::PathSegment { ident: n.ident.clone(), arguments: syn::PathArguments::None });
 318                                 imports.insert(n.ident.clone(), (full_path, syn::Path { leading_colon: Some(syn::Token![::](Span::call_site())), segments: path }));
 319                         },
 320                         syn::UseTree::Group(g) => {
 321                                 for i in g.items.iter() {
 322                                         Self::process_use_intern(imports, i, partial_path, path.clone());
 323                                 }
 324                         },
 325                         syn::UseTree::Rename(r) => {
 326                                 let full_path = format!("{}{}", partial_path, r.ident);
 327                                 path.push(syn::PathSegment { ident: r.ident.clone(), arguments: syn::PathArguments::None });
 328                                 imports.insert(r.rename.clone(), (full_path, syn::Path { leading_colon: Some(syn::Token![::](Span::call_site())), segments: path }));
 329                         },
 330                         syn::UseTree::Glob(_) => {
 331                                 eprintln!("Ignoring * use for {} - this may result in resolution failures", partial_path);
 332                         },
 333                 }
 334         }
 335
 336         fn process_use(imports: &mut HashMap<syn::Ident, (String, syn::Path)>, u: &syn::ItemUse) {
 337                 if let syn::Visibility::Public(_) = u.vis {
 338                         // We actually only use these for #[cfg(fuzztarget)]
 339                         eprintln!("Ignoring pub(use) tree!");
 340                         return;
 341                 }
 342                 if u.leading_colon.is_some() { eprintln!("Ignoring leading-colon use!"); return; }
 343                 Self::process_use_intern(imports, &u.tree, "", syn::punctuated::Punctuated::new());
 344         }
 345
 346         fn insert_primitive(imports: &mut HashMap<syn::Ident, (String, syn::Path)>, id: &str) {
 347                 let ident = syn::Ident::new(id, Span::call_site());
 348                 let mut path = syn::punctuated::Punctuated::new();
 349                 path.push(syn::PathSegment { ident: ident.clone(), arguments: syn::PathArguments::None });
 350                 imports.insert(ident, (id.to_owned(), syn::Path { leading_colon: Some(syn::Token![::](Span::call_site())), segments: path }));
 351         }
 352
 353         pub fn new(module_path: &'mod_lifetime str, contents: &'crate_lft [syn::Item]) -> Self {
 354                 let mut imports = HashMap::new();
 355                 // Add primitives to the "imports" list:
 356                 Self::insert_primitive(&mut imports, "bool");
 357                 Self::insert_primitive(&mut imports, "u64");
 358                 Self::insert_primitive(&mut imports, "u32");
 359                 Self::insert_primitive(&mut imports, "u16");
 360                 Self::insert_primitive(&mut imports, "u8");
 361                 Self::insert_primitive(&mut imports, "usize");
 362                 Self::insert_primitive(&mut imports, "str");
 363                 Self::insert_primitive(&mut imports, "String");
 364
 365                 // These are here to allow us to print native Rust types in trait fn impls even if we don't
 366                 // have C mappings:
 367                 Self::insert_primitive(&mut imports, "Result");
 368                 Self::insert_primitive(&mut imports, "Vec");
 369                 Self::insert_primitive(&mut imports, "Option");
 370
 371                 let mut declared = HashMap::new();
 372                 let mut priv_modules = HashSet::new();
 373
 374                 for item in contents.iter() {
 375                         match item {
 376                                 syn::Item::Use(u) => Self::process_use(&mut imports, &u),
 377                                 syn::Item::Struct(s) => {
 378                                         if let syn::Visibility::Public(_) = s.vis {
 379                                                 match export_status(&s.attrs) {
 380                                                         ExportStatus::Export => { declared.insert(s.ident.clone(), DeclType::StructImported); },
 381                                                         ExportStatus::NoExport => { declared.insert(s.ident.clone(), DeclType::StructIgnored); },
 382                                                         ExportStatus::TestOnly => continue,
 383                                                 }
 384                                         }
 385                                 },
 386                                 syn::Item::Type(t) if export_status(&t.attrs) == ExportStatus::Export => {
 387                                         if let syn::Visibility::Public(_) = t.vis {
 388                                                 let mut process_alias = true;
 389                                                 for tok in t.generics.params.iter() {
 390                                                         if let syn::GenericParam::Lifetime(_) = tok {}
 391                                                         else { process_alias = false; }
 392                                                 }
 393                                                 if process_alias {
 394                                                         match &*t.ty {
 395                                                                 syn::Type::Path(_) => { declared.insert(t.ident.clone(), DeclType::StructImported); },
 396                                                                 _ => {},
 397                                                         }
 398                                                 }
 399                                         }
 400                                 },
 401                                 syn::Item::Enum(e) => {
 402                                         if let syn::Visibility::Public(_) = e.vis {
 403                                                 match export_status(&e.attrs) {
 404                                                         ExportStatus::Export if is_enum_opaque(e) => { declared.insert(e.ident.clone(), DeclType::EnumIgnored); },
 405                                                         ExportStatus::Export => { declared.insert(e.ident.clone(), DeclType::MirroredEnum); },
 406                                                         _ => continue,
 407                                                 }
 408                                         }
 409                                 },
 410                                 syn::Item::Trait(t) if export_status(&t.attrs) == ExportStatus::Export => {
 411                                         if let syn::Visibility::Public(_) = t.vis {
 412                                                 declared.insert(t.ident.clone(), DeclType::Trait(t));
 413                                         }
 414                                 },
 415                                 syn::Item::Mod(m) => {
 416                                         priv_modules.insert(m.ident.clone());
 417                                 },
 418                                 _ => {},
 419                         }
 420                 }
 421
 422                 Self { module_path, imports, declared, priv_modules }
 423         }
 424
 425         pub fn get_declared_type(&self, ident: &syn::Ident) -> Option<&DeclType<'crate_lft>> {
 426                 self.declared.get(ident)
 427         }
 428
 429         pub fn maybe_resolve_declared(&self, id: &syn::Ident) -> Option<&DeclType<'crate_lft>> {
 430                 self.declared.get(id)
 431         }
 432
 433         pub fn maybe_resolve_ident(&self, id: &syn::Ident) -> Option<String> {
 434                 if let Some((imp, _)) = self.imports.get(id) {
 435                         Some(imp.clone())
 436                 } else if self.declared.get(id).is_some() {
 437                         Some(self.module_path.to_string() + "::" + &format!("{}", id))
 438                 } else { None }
 439         }
 440
 441         pub fn maybe_resolve_non_ignored_ident(&self, id: &syn::Ident) -> Option<String> {
 442                 if let Some((imp, _)) = self.imports.get(id) {
 443                         Some(imp.clone())
 444                 } else if let Some(decl_type) = self.declared.get(id) {
 445                         match decl_type {
 446                                 DeclType::StructIgnored => None,
 447                                 _ => Some(self.module_path.to_string() + "::" + &format!("{}", id)),
 448                         }
 449                 } else { None }
 450         }
 451
 452         pub fn maybe_resolve_path(&self, p_arg: &syn::Path, generics: Option<&GenericTypes>) -> Option<String> {
 453                 let p = if let Some(gen_types) = generics {
 454                         if let Some((_, synpath)) = gen_types.maybe_resolve_path(p_arg) {
 455                                 synpath
 456                         } else { p_arg }
 457                 } else { p_arg };
 458
 459                 if p.leading_colon.is_some() {
 460                         Some(p.segments.iter().enumerate().map(|(idx, seg)| {
 461                                 format!("{}{}", if idx == 0 { "" } else { "::" }, seg.ident)
 462                         }).collect())
 463                 } else if let Some(id) = p.get_ident() {
 464                         self.maybe_resolve_ident(id)
 465                 } else {
 466                         if p.segments.len() == 1 {
 467                                 let seg = p.segments.iter().next().unwrap();
 468                                 return self.maybe_resolve_ident(&seg.ident);
 469                         }
 470                         let mut seg_iter = p.segments.iter();
 471                         let first_seg = seg_iter.next().unwrap();
 472                         let remaining: String = seg_iter.map(|seg| {
 473                                 format!("::{}", seg.ident)
 474                         }).collect();
 475                         if let Some((imp, _)) = self.imports.get(&first_seg.ident) {
 476                                 if remaining != "" {
 477                                         Some(imp.clone() + &remaining)
 478                                 } else {
 479                                         Some(imp.clone())
 480                                 }
 481                         } else if let Some(_) = self.priv_modules.get(&first_seg.ident) {
 482                                 Some(format!("{}::{}{}", self.module_path, first_seg.ident, remaining))
 483                         } else { None }
 484                 }
 485         }
 486
 487         /// Map all the Paths in a Type into absolute paths given a set of imports (generated via process_use_intern)
 488         pub fn resolve_imported_refs(&self, mut ty: syn::Type) -> syn::Type {
 489                 match &mut ty {
 490                         syn::Type::Path(p) => {
 491                                 if let Some(ident) = p.path.get_ident() {
 492                                         if let Some((_, newpath)) = self.imports.get(ident) {
 493                                                 p.path = newpath.clone();
 494                                         }
 495                                 } else { unimplemented!(); }
 496                         },
 497                         syn::Type::Reference(r) => {
 498                                 r.elem = Box::new(self.resolve_imported_refs((*r.elem).clone()));
 499                         },
 500                         syn::Type::Slice(s) => {
 501                                 s.elem = Box::new(self.resolve_imported_refs((*s.elem).clone()));
 502                         },
 503                         syn::Type::Tuple(t) => {
 504                                 for e in t.elems.iter_mut() {
 505                                         *e = self.resolve_imported_refs(e.clone());
 506                                 }
 507                         },
 508                         _ => unimplemented!(),
 509                 }
 510                 ty
 511         }
 512 }
 513
 514 // templates_defined is walked to write the C++ header, so if we use the default hashing it get
 515 // reordered on each genbindings run. Instead, we use SipHasher (which defaults to 0-keys) so that
 516 // the sorting is stable across runs. It is deprecated, but the "replacement" doesn't actually
 517 // accomplish the same goals, so we just ignore it.
 518 #[allow(deprecated)]
 519 pub type NonRandomHash = hash::BuildHasherDefault<hash::SipHasher>;
 520
 521 /// Top-level struct tracking everything which has been defined while walking the crate.
 522 pub struct CrateTypes<'a> {
 523         /// This may contain structs or enums, but only when either is mapped as
 524         /// struct X { inner: *mut originalX, .. }
 525         pub opaques: HashMap<String, &'a syn::Ident>,
 526         /// Enums which are mapped as C enums with conversion functions
 527         pub mirrored_enums: HashMap<String, &'a syn::ItemEnum>,
 528         /// Traits which are mapped as a pointer + jump table
 529         pub traits: HashMap<String, &'a syn::ItemTrait>,
 530         /// Aliases from paths to some other Type
 531         pub type_aliases: HashMap<String, syn::Type>,
 532         /// Value is an alias to Key (maybe with some generics)
 533         pub reverse_alias_map: HashMap<String, Vec<(syn::Path, syn::PathArguments)>>,
 534         /// Template continer types defined, map from mangled type name -> whether a destructor fn
 535         /// exists.
 536         ///
 537         /// This is used at the end of processing to make C++ wrapper classes
 538         pub templates_defined: HashMap<String, bool, NonRandomHash>,
 539         /// The output file for any created template container types, written to as we find new
 540         /// template containers which need to be defined.
 541         pub template_file: &'a mut File,
 542         /// Set of containers which are clonable
 543         pub clonable_types: HashSet<String>,
 544         /// Key impls Value
 545         pub trait_impls: HashMap<String, Vec<String>>,
 546 }
 547
 548 /// A struct which tracks resolving rust types into C-mapped equivalents, exists for one specific
 549 /// module but contains a reference to the overall CrateTypes tracking.
 550 pub struct TypeResolver<'mod_lifetime, 'crate_lft: 'mod_lifetime> {
 551         pub orig_crate: &'mod_lifetime str,
 552         pub module_path: &'mod_lifetime str,
 553         pub crate_types: &'mod_lifetime mut CrateTypes<'crate_lft>,
 554         types: ImportResolver<'mod_lifetime, 'crate_lft>,
 555 }
 556
 557 /// Returned by write_empty_rust_val_check_suffix to indicate what type of dereferencing needs to
 558 /// happen to get the inner value of a generic.
 559 enum EmptyValExpectedTy {
 560         /// A type which has a flag for being empty (eg an array where we treat all-0s as empty).
 561         NonPointer,
 562         /// A pointer that we want to dereference and move out of.
 563         OwnedPointer,
 564         /// A pointer which we want to convert to a reference.
 565         ReferenceAsPointer,
 566 }
 567
 568 impl<'a, 'c: 'a> TypeResolver<'a, 'c> {
 569         pub fn new(orig_crate: &'a str, module_path: &'a str, types: ImportResolver<'a, 'c>, crate_types: &'a mut CrateTypes<'c>) -> Self {
 570                 Self { orig_crate, module_path, types, crate_types }
 571         }
 572
 573         // *************************************************
 574         // *** Well know type and conversion definitions ***
 575         // *************************************************
 576
 577         /// Returns true we if can just skip passing this to C entirely
 578         fn skip_path(&self, full_path: &str) -> bool {
 579                 full_path == "bitcoin::secp256k1::Secp256k1" ||
 580                 full_path == "bitcoin::secp256k1::Signing" ||
 581                 full_path == "bitcoin::secp256k1::Verification"
 582         }
 583         /// Returns true we if can just skip passing this to C entirely
 584         fn no_arg_path_to_rust(&self, full_path: &str) -> &str {
 585                 if full_path == "bitcoin::secp256k1::Secp256k1" {
 586                         "&bitcoin::secp256k1::Secp256k1::new()"
 587                 } else { unimplemented!(); }
 588         }
 589
 590         /// Returns true if the object is a primitive and is mapped as-is with no conversion
 591         /// whatsoever.
 592         pub fn is_primitive(&self, full_path: &str) -> bool {
 593                 match full_path {
 594                         "bool" => true,
 595                         "u64" => true,
 596                         "u32" => true,
 597                         "u16" => true,
 598                         "u8" => true,
 599                         "usize" => true,
 600                         _ => false,
 601                 }
 602         }
 603         pub fn is_clonable(&self, ty: &str) -> bool {
 604                 if self.crate_types.clonable_types.contains(ty) { return true; }
 605                 if self.is_primitive(ty) { return true; }
 606                 match ty {
 607                         "()" => true,
 608                         "crate::c_types::Signature" => true,
 609                         "crate::c_types::TxOut" => true,
 610                         _ => false,
 611                 }
 612         }
 613         /// Gets the C-mapped type for types which are outside of the crate, or which are manually
 614         /// ignored by for some reason need mapping anyway.
 615         fn c_type_from_path<'b>(&self, full_path: &'b str, is_ref: bool, _ptr_for_ref: bool) -> Option<&'b str> {
 616                 if self.is_primitive(full_path) {
 617                         return Some(full_path);
 618                 }
 619                 match full_path {
 620                         "Result" => Some("crate::c_types::derived::CResult"),
 621                         "Vec" if !is_ref => Some("crate::c_types::derived::CVec"),
 622                         "Option" => Some(""),
 623
 624                         // Note that no !is_ref types can map to an array because Rust and C's call semantics
 625                         // for arrays are different (https://github.com/eqrion/cbindgen/issues/528)
 626
 627                         "[u8; 32]" if !is_ref => Some("crate::c_types::ThirtyTwoBytes"),
 628                         "[u8; 16]" if !is_ref => Some("crate::c_types::SixteenBytes"),
 629                         "[u8; 10]" if !is_ref => Some("crate::c_types::TenBytes"),
 630                         "[u8; 4]" if !is_ref => Some("crate::c_types::FourBytes"),
 631                         "[u8; 3]" if !is_ref => Some("crate::c_types::ThreeBytes"), // Used for RGB values
 632
 633                         "str" if is_ref => Some("crate::c_types::Str"),
 634                         "String" if !is_ref => Some("crate::c_types::derived::CVec_u8Z"),
 635                         "String" if is_ref => Some("crate::c_types::Str"),
 636
 637                         "std::time::Duration" => Some("u64"),
 638
 639                         "bitcoin::secp256k1::key::PublicKey" => Some("crate::c_types::PublicKey"),
 640                         "bitcoin::secp256k1::Signature" => Some("crate::c_types::Signature"),
 641                         "bitcoin::secp256k1::key::SecretKey" if is_ref  => Some("*const [u8; 32]"),
 642                         "bitcoin::secp256k1::key::SecretKey" if !is_ref => Some("crate::c_types::SecretKey"),
 643                         "bitcoin::secp256k1::Error" if !is_ref => Some("crate::c_types::Secp256k1Error"),
 644                         "bitcoin::blockdata::script::Script" if is_ref => Some("crate::c_types::u8slice"),
 645                         "bitcoin::blockdata::script::Script" if !is_ref => Some("crate::c_types::derived::CVec_u8Z"),
 646                         "bitcoin::blockdata::transaction::OutPoint" => Some("crate::chain::transaction::OutPoint"),
 647                         "bitcoin::blockdata::transaction::Transaction" => Some("crate::c_types::Transaction"),
 648                         "bitcoin::blockdata::transaction::TxOut" if !is_ref => Some("crate::c_types::TxOut"),
 649                         "bitcoin::network::constants::Network" => Some("crate::bitcoin::network::Network"),
 650                         "bitcoin::blockdata::block::BlockHeader" if is_ref  => Some("*const [u8; 80]"),
 651                         "bitcoin::blockdata::block::Block" if is_ref  => Some("crate::c_types::u8slice"),
 652
 653                         // Newtypes that we just expose in their original form.
 654                         "bitcoin::hash_types::Txid" if is_ref  => Some("*const [u8; 32]"),
 655                         "bitcoin::hash_types::Txid" if !is_ref => Some("crate::c_types::ThirtyTwoBytes"),
 656                         "bitcoin::hash_types::BlockHash" if is_ref  => Some("*const [u8; 32]"),
 657                         "bitcoin::hash_types::BlockHash" if !is_ref => Some("crate::c_types::ThirtyTwoBytes"),
 658                         "bitcoin::secp256k1::Message" if !is_ref => Some("crate::c_types::ThirtyTwoBytes"),
 659                         "ln::channelmanager::PaymentHash" if is_ref => Some("*const [u8; 32]"),
 660                         "ln::channelmanager::PaymentHash" if !is_ref => Some("crate::c_types::ThirtyTwoBytes"),
 661                         "ln::channelmanager::PaymentPreimage" if is_ref => Some("*const [u8; 32]"),
 662                         "ln::channelmanager::PaymentPreimage" if !is_ref => Some("crate::c_types::ThirtyTwoBytes"),
 663                         "ln::channelmanager::PaymentSecret" if is_ref => Some("crate::c_types::ThirtyTwoBytes"),
 664                         "ln::channelmanager::PaymentSecret" if !is_ref => Some("crate::c_types::ThirtyTwoBytes"),
 665
 666                         // Override the default since Records contain an fmt with a lifetime:
 667                         "util::logger::Record" => Some("*const std::os::raw::c_char"),
 668
 669                         _ => None,
 670                 }
 671         }
 672
 673         fn from_c_conversion_new_var_from_path<'b>(&self, _full_path: &str, _is_ref: bool) -> Option<(&'b str, &'b str)> {
 674                 None
 675         }
 676         fn from_c_conversion_prefix_from_path<'b>(&self, full_path: &str, is_ref: bool) -> Option<String> {
 677                 if self.is_primitive(full_path) {
 678                         return Some("".to_owned());
 679                 }
 680                 match full_path {
 681                         "Vec" if !is_ref => Some("local_"),
 682                         "Result" if !is_ref => Some("local_"),
 683                         "Option" if is_ref => Some("&local_"),
 684                         "Option" => Some("local_"),
 685
 686                         "[u8; 32]" if is_ref => Some("unsafe { &*"),
 687                         "[u8; 32]" if !is_ref => Some(""),
 688                         "[u8; 16]" if !is_ref => Some(""),
 689                         "[u8; 10]" if !is_ref => Some(""),
 690                         "[u8; 4]" if !is_ref => Some(""),
 691                         "[u8; 3]" if !is_ref => Some(""),
 692
 693                         "[u8]" if is_ref => Some(""),
 694                         "[usize]" if is_ref => Some(""),
 695
 696                         "str" if is_ref => Some(""),
 697                         "String" if !is_ref => Some("String::from_utf8("),
 698                         // Note that we'll panic for String if is_ref, as we only have non-owned memory, we
 699                         // cannot create a &String.
 700
 701                         "std::time::Duration" => Some("std::time::Duration::from_secs("),
 702
 703                         "bitcoin::secp256k1::key::PublicKey" if is_ref => Some("&"),
 704                         "bitcoin::secp256k1::key::PublicKey" => Some(""),
 705                         "bitcoin::secp256k1::Signature" if is_ref => Some("&"),
 706                         "bitcoin::secp256k1::Signature" => Some(""),
 707                         "bitcoin::secp256k1::key::SecretKey" if is_ref => Some("&::bitcoin::secp256k1::key::SecretKey::from_slice(&unsafe { *"),
 708                         "bitcoin::secp256k1::key::SecretKey" if !is_ref => Some(""),
 709                         "bitcoin::blockdata::script::Script" if is_ref => Some("&::bitcoin::blockdata::script::Script::from(Vec::from("),
 710                         "bitcoin::blockdata::script::Script" if !is_ref => Some("::bitcoin::blockdata::script::Script::from("),
 711                         "bitcoin::blockdata::transaction::Transaction" if is_ref => Some("&"),
 712                         "bitcoin::blockdata::transaction::Transaction" => Some(""),
 713                         "bitcoin::blockdata::transaction::TxOut" if !is_ref => Some(""),
 714                         "bitcoin::network::constants::Network" => Some(""),
 715                         "bitcoin::blockdata::block::BlockHeader" => Some("&::bitcoin::consensus::encode::deserialize(unsafe { &*"),
 716                         "bitcoin::blockdata::block::Block" if is_ref => Some("&::bitcoin::consensus::encode::deserialize("),
 717
 718                         // Newtypes that we just expose in their original form.
 719                         "bitcoin::hash_types::Txid" if is_ref => Some("&::bitcoin::hash_types::Txid::from_slice(&unsafe { &*"),
 720                         "bitcoin::hash_types::Txid" if !is_ref => Some("::bitcoin::hash_types::Txid::from_slice(&"),
 721                         "bitcoin::hash_types::BlockHash" => Some("::bitcoin::hash_types::BlockHash::from_slice(&"),
 722                         "ln::channelmanager::PaymentHash" if !is_ref => Some("::lightning::ln::channelmanager::PaymentHash("),
 723                         "ln::channelmanager::PaymentHash" if is_ref => Some("&::lightning::ln::channelmanager::PaymentHash(unsafe { *"),
 724                         "ln::channelmanager::PaymentPreimage" if !is_ref => Some("::lightning::ln::channelmanager::PaymentPreimage("),
 725                         "ln::channelmanager::PaymentPreimage" if is_ref => Some("&::lightning::ln::channelmanager::PaymentPreimage(unsafe { *"),
 726                         "ln::channelmanager::PaymentSecret" => Some("::lightning::ln::channelmanager::PaymentSecret("),
 727
 728                         // List of traits we map (possibly during processing of other files):
 729                         "crate::util::logger::Logger" => Some(""),
 730
 731                         _ => None,
 732                 }.map(|s| s.to_owned())
 733         }
 734         fn from_c_conversion_suffix_from_path<'b>(&self, full_path: &str, is_ref: bool) -> Option<String> {
 735                 if self.is_primitive(full_path) {
 736                         return Some("".to_owned());
 737                 }
 738                 match full_path {
 739                         "Vec" if !is_ref => Some(""),
 740                         "Option" => Some(""),
 741                         "Result" if !is_ref => Some(""),
 742
 743                         "[u8; 32]" if is_ref => Some("}"),
 744                         "[u8; 32]" if !is_ref => Some(".data"),
 745                         "[u8; 16]" if !is_ref => Some(".data"),
 746                         "[u8; 10]" if !is_ref => Some(".data"),
 747                         "[u8; 4]" if !is_ref => Some(".data"),
 748                         "[u8; 3]" if !is_ref => Some(".data"),
 749
 750                         "[u8]" if is_ref => Some(".to_slice()"),
 751                         "[usize]" if is_ref => Some(".to_slice()"),
 752
 753                         "str" if is_ref => Some(".into()"),
 754                         "String" if !is_ref => Some(".into_rust()).unwrap()"),
 755
 756                         "std::time::Duration" => Some(")"),
 757
 758                         "bitcoin::secp256k1::key::PublicKey" => Some(".into_rust()"),
 759                         "bitcoin::secp256k1::Signature" => Some(".into_rust()"),
 760                         "bitcoin::secp256k1::key::SecretKey" if !is_ref => Some(".into_rust()"),
 761                         "bitcoin::secp256k1::key::SecretKey" if is_ref => Some("}[..]).unwrap()"),
 762                         "bitcoin::blockdata::script::Script" if is_ref => Some(".to_slice()))"),
 763                         "bitcoin::blockdata::script::Script" if !is_ref => Some(".into_rust())"),
 764                         "bitcoin::blockdata::transaction::Transaction" => Some(".into_bitcoin()"),
 765                         "bitcoin::blockdata::transaction::TxOut" if !is_ref => Some(".into_rust()"),
 766                         "bitcoin::network::constants::Network" => Some(".into_bitcoin()"),
 767                         "bitcoin::blockdata::block::BlockHeader" => Some(" }).unwrap()"),
 768                         "bitcoin::blockdata::block::Block" => Some(".to_slice()).unwrap()"),
 769
 770                         // Newtypes that we just expose in their original form.
 771                         "bitcoin::hash_types::Txid" if is_ref => Some(" }[..]).unwrap()"),
 772                         "bitcoin::hash_types::Txid" => Some(".data[..]).unwrap()"),
 773                         "bitcoin::hash_types::BlockHash" if !is_ref => Some(".data[..]).unwrap()"),
 774                         "ln::channelmanager::PaymentHash" if !is_ref => Some(".data)"),
 775                         "ln::channelmanager::PaymentHash" if is_ref => Some(" })"),
 776                         "ln::channelmanager::PaymentPreimage" if !is_ref => Some(".data)"),
 777                         "ln::channelmanager::PaymentPreimage" if is_ref => Some(" })"),
 778                         "ln::channelmanager::PaymentSecret" => Some(".data)"),
 779
 780                         // List of traits we map (possibly during processing of other files):
 781                         "crate::util::logger::Logger" => Some(""),
 782
 783                         _ => None,
 784                 }.map(|s| s.to_owned())
 785         }
 786
 787         fn to_c_conversion_new_var_from_path<'b>(&self, full_path: &str, is_ref: bool) -> Option<(&'b str, &'b str)> {
 788                 if self.is_primitive(full_path) {
 789                         return None;
 790                 }
 791                 match full_path {
 792                         "[u8]" if is_ref => Some(("crate::c_types::u8slice::from_slice(", ")")),
 793                         "[usize]" if is_ref => Some(("crate::c_types::usizeslice::from_slice(", ")")),
 794
 795                         "bitcoin::blockdata::transaction::Transaction" if is_ref => Some(("::bitcoin::consensus::encode::serialize(", ")")),
 796                         "bitcoin::blockdata::transaction::Transaction" if !is_ref => Some(("::bitcoin::consensus::encode::serialize(&", ")")),
 797                         "bitcoin::blockdata::block::BlockHeader" if is_ref => Some(("{ let mut s = [0u8; 80]; s[..].copy_from_slice(&::bitcoin::consensus::encode::serialize(", ")); s }")),
 798                         "bitcoin::blockdata::block::Block" if is_ref => Some(("::bitcoin::consensus::encode::serialize(", ")")),
 799                         "bitcoin::hash_types::Txid" => None,
 800
 801                         // Override the default since Records contain an fmt with a lifetime:
 802                         // TODO: We should include the other record fields
 803                         "util::logger::Record" => Some(("std::ffi::CString::new(format!(\"{}\", ", ".args)).unwrap()")),
 804                         _ => None,
 805                 }.map(|s| s.to_owned())
 806         }
 807         fn to_c_conversion_inline_prefix_from_path(&self, full_path: &str, is_ref: bool, _ptr_for_ref: bool) -> Option<String> {
 808                 if self.is_primitive(full_path) {
 809                         return Some("".to_owned());
 810                 }
 811                 match full_path {
 812                         "Result" if !is_ref => Some("local_"),
 813                         "Vec" if !is_ref => Some("local_"),
 814                         "Option" => Some("local_"),
 815
 816                         "[u8; 32]" if !is_ref => Some("crate::c_types::ThirtyTwoBytes { data: "),
 817                         "[u8; 32]" if is_ref => Some("&"),
 818                         "[u8; 16]" if !is_ref => Some("crate::c_types::SixteenBytes { data: "),
 819                         "[u8; 10]" if !is_ref => Some("crate::c_types::TenBytes { data: "),
 820                         "[u8; 4]" if !is_ref => Some("crate::c_types::FourBytes { data: "),
 821                         "[u8; 3]" if is_ref => Some("&"),
 822
 823                         "[u8]" if is_ref => Some("local_"),
 824                         "[usize]" if is_ref => Some("local_"),
 825
 826                         "str" if is_ref => Some(""),
 827                         "String" => Some(""),
 828
 829                         "std::time::Duration" => Some(""),
 830
 831                         "bitcoin::secp256k1::key::PublicKey" => Some("crate::c_types::PublicKey::from_rust(&"),
 832                         "bitcoin::secp256k1::Signature" => Some("crate::c_types::Signature::from_rust(&"),
 833                         "bitcoin::secp256k1::key::SecretKey" if is_ref  => Some(""),
 834                         "bitcoin::secp256k1::key::SecretKey" if !is_ref => Some("crate::c_types::SecretKey::from_rust("),
 835                         "bitcoin::secp256k1::Error" if !is_ref => Some("crate::c_types::Secp256k1Error::from_rust("),
 836                         "bitcoin::blockdata::script::Script" if is_ref => Some("crate::c_types::u8slice::from_slice(&"),
 837                         "bitcoin::blockdata::script::Script" if !is_ref => Some(""),
 838                         "bitcoin::blockdata::transaction::Transaction" => Some("crate::c_types::Transaction::from_vec(local_"),
 839                         "bitcoin::blockdata::transaction::OutPoint" => Some("crate::c_types::bitcoin_to_C_outpoint("),
 840                         "bitcoin::blockdata::transaction::TxOut" if !is_ref => Some("crate::c_types::TxOut::from_rust("),
 841                         "bitcoin::blockdata::block::BlockHeader" if is_ref => Some("&local_"),
 842                         "bitcoin::blockdata::block::Block" if is_ref => Some("crate::c_types::u8slice::from_slice(&local_"),
 843
 844                         "bitcoin::hash_types::Txid" if !is_ref => Some("crate::c_types::ThirtyTwoBytes { data: "),
 845
 846                         // Newtypes that we just expose in their original form.
 847                         "bitcoin::hash_types::Txid" if is_ref => Some(""),
 848                         "bitcoin::hash_types::BlockHash" if is_ref => Some(""),
 849                         "bitcoin::hash_types::BlockHash" => Some("crate::c_types::ThirtyTwoBytes { data: "),
 850                         "bitcoin::secp256k1::Message" if !is_ref => Some("crate::c_types::ThirtyTwoBytes { data: "),
 851                         "ln::channelmanager::PaymentHash" if is_ref => Some("&"),
 852                         "ln::channelmanager::PaymentHash" if !is_ref => Some("crate::c_types::ThirtyTwoBytes { data: "),
 853                         "ln::channelmanager::PaymentPreimage" if is_ref => Some("&"),
 854                         "ln::channelmanager::PaymentPreimage" => Some("crate::c_types::ThirtyTwoBytes { data: "),
 855                         "ln::channelmanager::PaymentSecret" if !is_ref => Some("crate::c_types::ThirtyTwoBytes { data: "),
 856
 857                         // Override the default since Records contain an fmt with a lifetime:
 858                         "util::logger::Record" => Some("local_"),
 859
 860                         _ => None,
 861                 }.map(|s| s.to_owned())
 862         }
 863         fn to_c_conversion_inline_suffix_from_path(&self, full_path: &str, is_ref: bool, _ptr_for_ref: bool) -> Option<String> {
 864                 if self.is_primitive(full_path) {
 865                         return Some("".to_owned());
 866                 }
 867                 match full_path {
 868                         "Result" if !is_ref => Some(""),
 869                         "Vec" if !is_ref => Some(".into()"),
 870                         "Option" => Some(""),
 871
 872                         "[u8; 32]" if !is_ref => Some(" }"),
 873                         "[u8; 32]" if is_ref => Some(""),
 874                         "[u8; 16]" if !is_ref => Some(" }"),
 875                         "[u8; 10]" if !is_ref => Some(" }"),
 876                         "[u8; 4]" if !is_ref => Some(" }"),
 877                         "[u8; 3]" if is_ref => Some(""),
 878
 879                         "[u8]" if is_ref => Some(""),
 880                         "[usize]" if is_ref => Some(""),
 881
 882                         "str" if is_ref => Some(".into()"),
 883                         "String" if !is_ref => Some(".into_bytes().into()"),
 884                         "String" if is_ref => Some(".as_str().into()"),
 885
 886                         "std::time::Duration" => Some(".as_secs()"),
 887
 888                         "bitcoin::secp256k1::key::PublicKey" => Some(")"),
 889                         "bitcoin::secp256k1::Signature" => Some(")"),
 890                         "bitcoin::secp256k1::key::SecretKey" if !is_ref => Some(")"),
 891                         "bitcoin::secp256k1::key::SecretKey" if is_ref => Some(".as_ref()"),
 892                         "bitcoin::secp256k1::Error" if !is_ref => Some(")"),
 893                         "bitcoin::blockdata::script::Script" if is_ref => Some("[..])"),
 894                         "bitcoin::blockdata::script::Script" if !is_ref => Some(".into_bytes().into()"),
 895                         "bitcoin::blockdata::transaction::Transaction" => Some(")"),
 896                         "bitcoin::blockdata::transaction::OutPoint" => Some(")"),
 897                         "bitcoin::blockdata::transaction::TxOut" if !is_ref => Some(")"),
 898                         "bitcoin::blockdata::block::BlockHeader" if is_ref => Some(""),
 899                         "bitcoin::blockdata::block::Block" if is_ref => Some(")"),
 900
 901                         "bitcoin::hash_types::Txid" if !is_ref => Some(".into_inner() }"),
 902
 903                         // Newtypes that we just expose in their original form.
 904                         "bitcoin::hash_types::Txid" if is_ref => Some(".as_inner()"),
 905                         "bitcoin::hash_types::BlockHash" if is_ref => Some(".as_inner()"),
 906                         "bitcoin::hash_types::BlockHash" => Some(".into_inner() }"),
 907                         "bitcoin::secp256k1::Message" if !is_ref => Some(".as_ref().clone() }"),
 908                         "ln::channelmanager::PaymentHash" if is_ref => Some(".0"),
 909                         "ln::channelmanager::PaymentHash" => Some(".0 }"),
 910                         "ln::channelmanager::PaymentPreimage" if is_ref => Some(".0"),
 911                         "ln::channelmanager::PaymentPreimage" => Some(".0 }"),
 912                         "ln::channelmanager::PaymentSecret" if !is_ref => Some(".0 }"),
 913
 914                         // Override the default since Records contain an fmt with a lifetime:
 915                         "util::logger::Record" => Some(".as_ptr()"),
 916
 917                         _ => None,
 918                 }.map(|s| s.to_owned())
 919         }
 920
 921         fn empty_val_check_suffix_from_path(&self, full_path: &str) -> Option<&str> {
 922                 match full_path {
 923                         "ln::channelmanager::PaymentSecret" => Some(".data == [0; 32]"),
 924                         "bitcoin::secp256k1::key::PublicKey" => Some(".is_null()"),
 925                         "bitcoin::secp256k1::Signature" => Some(".is_null()"),
 926                         _ => None
 927                 }
 928         }
 929
 930         // ****************************
 931         // *** Container Processing ***
 932         // ****************************
 933
 934         /// Returns the module path in the generated mapping crate to the containers which we generate
 935         /// when writing to CrateTypes::template_file.
 936         pub fn generated_container_path() -> &'static str {
 937                 "crate::c_types::derived"
 938         }
 939         /// Returns the module path in the generated mapping crate to the container templates, which
 940         /// are then concretized and put in the generated container path/template_file.
 941         fn container_templ_path() -> &'static str {
 942                 "crate::c_types"
 943         }
 944
 945         /// Returns true if this is a "transparent" container, ie an Option or a container which does
 946         /// not require a generated continer class.
 947         fn is_transparent_container(&self, full_path: &str, _is_ref: bool) -> bool {
 948                 full_path == "Option"
 949         }
 950         /// Returns true if this is a known, supported, non-transparent container.
 951         fn is_known_container(&self, full_path: &str, is_ref: bool) -> bool {
 952                 (full_path == "Result" && !is_ref) || (full_path == "Vec" && !is_ref) || full_path.ends_with("Tuple")
 953         }
 954         fn to_c_conversion_container_new_var<'b>(&self, generics: Option<&GenericTypes>, full_path: &str, is_ref: bool, single_contained: Option<&syn::Type>, var_name: &syn::Ident, var_access: &str)
 955                         // Returns prefix + Vec<(prefix, var-name-to-inline-convert)> + suffix
 956                         // expecting one element in the vec per generic type, each of which is inline-converted
 957                         -> Option<(&'b str, Vec<(String, String)>, &'b str)> {
 958                 match full_path {
 959                         "Result" if !is_ref => {
 960                                 Some(("match ",
 961                                                 vec![(" { Ok(mut o) => crate::c_types::CResultTempl::ok(".to_string(), "o".to_string()),
 962                                                         (").into(), Err(mut e) => crate::c_types::CResultTempl::err(".to_string(), "e".to_string())],
 963                                                 ").into() }"))
 964                         },
 965                         "Vec" if !is_ref => {
 966                                 Some(("Vec::new(); for item in ", vec![(format!(".drain(..) {{ local_{}.push(", var_name), "item".to_string())], "); }"))
 967                         },
 968                         "Slice" => {
 969                                 Some(("Vec::new(); for item in ", vec![(format!(".iter() {{ local_{}.push(", var_name), "**item".to_string())], "); }"))
 970                         },
 971                         "Option" => {
 972                                 if let Some(syn::Type::Path(p)) = single_contained {
 973                                         if self.c_type_has_inner_from_path(&self.resolve_path(&p.path, generics)) {
 974                                                 if is_ref {
 975                                                         return Some(("if ", vec![
 976                                                                 (".is_none() { std::ptr::null() } else { ".to_owned(), format!("({}.as_ref().unwrap())", var_access))
 977                                                                 ], " }"));
 978                                                 } else {
 979                                                         return Some(("if ", vec![
 980                                                                 (".is_none() { std::ptr::null_mut() } else { ".to_owned(), format!("({}.unwrap())", var_access))
 981                                                                 ], " }"));
 982                                                 }
 983                                         }
 984                                 }
 985                                 if let Some(t) = single_contained {
 986                                         let mut v = Vec::new();
 987                                         self.write_empty_rust_val(generics, &mut v, t);
 988                                         let s = String::from_utf8(v).unwrap();
 989                                         return Some(("if ", vec![
 990                                                 (format!(".is_none() {{ {} }} else {{ ", s), format!("({}.unwrap())", var_access))
 991                                                 ], " }"));
 992                                 } else { unreachable!(); }
 993                         },
 994                         _ => None,
 995                 }
 996         }
 997
 998         /// only_contained_has_inner implies that there is only one contained element in the container
 999         /// and it has an inner field (ie is an "opaque" type we've defined).
1000         fn from_c_conversion_container_new_var<'b>(&self, generics: Option<&GenericTypes>, full_path: &str, is_ref: bool, single_contained: Option<&syn::Type>, var_name: &syn::Ident, var_access: &str)
1001                         // Returns prefix + Vec<(prefix, var-name-to-inline-convert)> + suffix
1002                         // expecting one element in the vec per generic type, each of which is inline-converted
1003                         -> Option<(&'b str, Vec<(String, String)>, &'b str)> {
1004                 match full_path {
1005                         "Result" if !is_ref => {
1006                                 Some(("match ",
1007                                                 vec![(".result_ok { true => Ok(".to_string(), format!("(*unsafe {{ Box::from_raw(<*mut _>::take_ptr(&mut {}.contents.result)) }})", var_name)),
1008                                                      ("), false => Err(".to_string(), format!("(*unsafe {{ Box::from_raw(<*mut _>::take_ptr(&mut {}.contents.err)) }})", var_name))],
1009                                                 ")}"))
1010                         },
1011                         "Vec"|"Slice" if !is_ref => {
1012                                 Some(("Vec::new(); for mut item in ", vec![(format!(".into_rust().drain(..) {{ local_{}.push(", var_name), "item".to_string())], "); }"))
1013                         },
1014                         "Slice" if is_ref => {
1015                                 Some(("Vec::new(); for mut item in ", vec![(format!(".as_slice().iter() {{ local_{}.push(", var_name), "item".to_string())], "); }"))
1016                         },
1017                         "Option" => {
1018                                 if let Some(syn::Type::Path(p)) = single_contained {
1019                                         if self.c_type_has_inner_from_path(&self.resolve_path(&p.path, generics)) {
1020                                                 if is_ref {
1021                                                         return Some(("if ", vec![(".inner.is_null() { None } else { Some((*".to_string(), format!("{}", var_name))], ").clone()) }"))
1022                                                 } else {
1023                                                         return Some(("if ", vec![(".inner.is_null() { None } else { Some(".to_string(), format!("{}", var_name))], ") }"));
1024                                                 }
1025                                         }
1026                                 }
1027
1028                                 if let Some(t) = single_contained {
1029                                         let mut v = Vec::new();
1030                                         let ret_ref = self.write_empty_rust_val_check_suffix(generics, &mut v, t);
1031                                         let s = String::from_utf8(v).unwrap();
1032                                         match ret_ref {
1033                                                 EmptyValExpectedTy::ReferenceAsPointer =>
1034                                                         return Some(("if ", vec![
1035                                                                 (format!("{} {{ None }} else {{ Some(", s), format!("unsafe {{ &mut *{} }}", var_access))
1036                                                         ], ") }")),
1037                                                 EmptyValExpectedTy::OwnedPointer =>
1038                                                         return Some(("if ", vec![
1039                                                                 (format!("{} {{ None }} else {{ Some(", s), format!("unsafe {{ *Box::from_raw({}) }}", var_access))
1040                                                         ], ") }")),
1041                                                 EmptyValExpectedTy::NonPointer =>
1042                                                         return Some(("if ", vec![
1043                                                                 (format!("{} {{ None }} else {{ Some(", s), format!("{}", var_access))
1044                                                         ], ") }")),
1045                                         }
1046                                 } else { unreachable!(); }
1047                         },
1048                         _ => None,
1049                 }
1050         }
1051
1052         // *************************************************
1053         // *** Type definition during main.rs processing ***
1054         // *************************************************
1055
1056         pub fn get_declared_type(&'a self, ident: &syn::Ident) -> Option<&'a DeclType<'c>> {
1057                 self.types.get_declared_type(ident)
1058         }
1059         /// Returns true if the object at the given path is mapped as X { inner: *mut origX, .. }.
1060         pub fn c_type_has_inner_from_path(&self, full_path: &str) -> bool{
1061                 self.crate_types.opaques.get(full_path).is_some()
1062         }
1063
1064         pub fn maybe_resolve_ident(&self, id: &syn::Ident) -> Option<String> {
1065                 self.types.maybe_resolve_ident(id)
1066         }
1067
1068         pub fn maybe_resolve_non_ignored_ident(&self, id: &syn::Ident) -> Option<String> {
1069                 self.types.maybe_resolve_non_ignored_ident(id)
1070         }
1071
1072         pub fn maybe_resolve_path(&self, p_arg: &syn::Path, generics: Option<&GenericTypes>) -> Option<String> {
1073                 self.types.maybe_resolve_path(p_arg, generics)
1074         }
1075         pub fn resolve_path(&self, p: &syn::Path, generics: Option<&GenericTypes>) -> String {
1076                 self.maybe_resolve_path(p, generics).unwrap()
1077         }
1078
1079         // ***********************************
1080         // *** Original Rust Type Printing ***
1081         // ***********************************
1082
1083         fn in_rust_prelude(resolved_path: &str) -> bool {
1084                 match resolved_path {
1085                         "Vec" => true,
1086                         "Result" => true,
1087                         "Option" => true,
1088                         _ => false,
1089                 }
1090         }
1091
1092         fn write_rust_path<W: std::io::Write>(&self, w: &mut W, generics_resolver: Option<&GenericTypes>, path: &syn::Path) {
1093                 if let Some(resolved) = self.maybe_resolve_path(&path, generics_resolver) {
1094                         if self.is_primitive(&resolved) {
1095                                 write!(w, "{}", path.get_ident().unwrap()).unwrap();
1096                         } else {
1097                                 // TODO: We should have a generic "is from a dependency" check here instead of
1098                                 // checking for "bitcoin" explicitly.
1099                                 if resolved.starts_with("bitcoin::") || Self::in_rust_prelude(&resolved) {
1100                                         write!(w, "{}", resolved).unwrap();
1101                                 // If we're printing a generic argument, it needs to reference the crate, otherwise
1102                                 // the original crate:
1103                                 } else if self.maybe_resolve_path(&path, None).as_ref() == Some(&resolved) {
1104                                         write!(w, "{}::{}", self.orig_crate, resolved).unwrap();
1105                                 } else {
1106                                         write!(w, "crate::{}", resolved).unwrap();
1107                                 }
1108                         }
1109                         if let syn::PathArguments::AngleBracketed(args) = &path.segments.iter().last().unwrap().arguments {
1110                                 self.write_rust_generic_arg(w, generics_resolver, args.args.iter());
1111                         }
1112                 } else {
1113                         if path.leading_colon.is_some() {
1114                                 write!(w, "::").unwrap();
1115                         }
1116                         for (idx, seg) in path.segments.iter().enumerate() {
1117                                 if idx != 0 { write!(w, "::").unwrap(); }
1118                                 write!(w, "{}", seg.ident).unwrap();
1119                                 if let syn::PathArguments::AngleBracketed(args) = &seg.arguments {
1120                                         self.write_rust_generic_arg(w, generics_resolver, args.args.iter());
1121                                 }
1122                         }
1123                 }
1124         }
1125         pub fn write_rust_generic_param<'b, W: std::io::Write>(&self, w: &mut W, generics_resolver: Option<&GenericTypes>, generics: impl Iterator<Item=&'b syn::GenericParam>) {
1126                 let mut had_params = false;
1127                 for (idx, arg) in generics.enumerate() {
1128                         if idx != 0 { write!(w, ", ").unwrap(); } else { write!(w, "<").unwrap(); }
1129                         had_params = true;
1130                         match arg {
1131                                 syn::GenericParam::Lifetime(lt) => write!(w, "'{}", lt.lifetime.ident).unwrap(),
1132                                 syn::GenericParam::Type(t) => {
1133                                         write!(w, "{}", t.ident).unwrap();
1134                                         if t.colon_token.is_some() { write!(w, ":").unwrap(); }
1135                                         for (idx, bound) in t.bounds.iter().enumerate() {
1136                                                 if idx != 0 { write!(w, " + ").unwrap(); }
1137                                                 match bound {
1138                                                         syn::TypeParamBound::Trait(tb) => {
1139                                                                 if tb.paren_token.is_some() || tb.lifetimes.is_some() { unimplemented!(); }
1140                                                                 self.write_rust_path(w, generics_resolver, &tb.path);
1141                                                         },
1142                                                         _ => unimplemented!(),
1143                                                 }
1144                                         }
1145                                         if t.eq_token.is_some() || t.default.is_some() { unimplemented!(); }
1146                                 },
1147                                 _ => unimplemented!(),
1148                         }
1149                 }
1150                 if had_params { write!(w, ">").unwrap(); }
1151         }
1152
1153         pub fn write_rust_generic_arg<'b, W: std::io::Write>(&self, w: &mut W, generics_resolver: Option<&GenericTypes>, generics: impl Iterator<Item=&'b syn::GenericArgument>) {
1154                 write!(w, "<").unwrap();
1155                 for (idx, arg) in generics.enumerate() {
1156                         if idx != 0 { write!(w, ", ").unwrap(); }
1157                         match arg {
1158                                 syn::GenericArgument::Type(t) => self.write_rust_type(w, generics_resolver, t),
1159                                 _ => unimplemented!(),
1160                         }
1161                 }
1162                 write!(w, ">").unwrap();
1163         }
1164         pub fn write_rust_type<W: std::io::Write>(&self, w: &mut W, generics: Option<&GenericTypes>, t: &syn::Type) {
1165                 match t {
1166                         syn::Type::Path(p) => {
1167                                 if p.qself.is_some() {
1168                                         unimplemented!();
1169                                 }
1170                                 self.write_rust_path(w, generics, &p.path);
1171                         },
1172                         syn::Type::Reference(r) => {
1173                                 write!(w, "&").unwrap();
1174                                 if let Some(lft) = &r.lifetime {
1175                                         write!(w, "'{} ", lft.ident).unwrap();
1176                                 }
1177                                 if r.mutability.is_some() {
1178                                         write!(w, "mut ").unwrap();
1179                                 }
1180                                 self.write_rust_type(w, generics, &*r.elem);
1181                         },
1182                         syn::Type::Array(a) => {
1183                                 write!(w, "[").unwrap();
1184                                 self.write_rust_type(w, generics, &a.elem);
1185                                 if let syn::Expr::Lit(l) = &a.len {
1186                                         if let syn::Lit::Int(i) = &l.lit {
1187                                                 write!(w, "; {}]", i).unwrap();
1188                                         } else { unimplemented!(); }
1189                                 } else { unimplemented!(); }
1190                         }
1191                         syn::Type::Slice(s) => {
1192                                 write!(w, "[").unwrap();
1193                                 self.write_rust_type(w, generics, &s.elem);
1194                                 write!(w, "]").unwrap();
1195                         },
1196                         syn::Type::Tuple(s) => {
1197                                 write!(w, "(").unwrap();
1198                                 for (idx, t) in s.elems.iter().enumerate() {
1199                                         if idx != 0 { write!(w, ", ").unwrap(); }
1200                                         self.write_rust_type(w, generics, &t);
1201                                 }
1202                                 write!(w, ")").unwrap();
1203                         },
1204                         _ => unimplemented!(),
1205                 }
1206         }
1207
1208         /// Prints a constructor for something which is "uninitialized" (but obviously not actually
1209         /// unint'd memory).
1210         pub fn write_empty_rust_val<W: std::io::Write>(&self, generics: Option<&GenericTypes>, w: &mut W, t: &syn::Type) {
1211                 match t {
1212                         syn::Type::Path(p) => {
1213                                 let resolved = self.resolve_path(&p.path, generics);
1214                                 if self.crate_types.opaques.get(&resolved).is_some() {
1215                                         write!(w, "crate::{} {{ inner: std::ptr::null_mut(), is_owned: true }}", resolved).unwrap();
1216                                 } else {
1217                                         // Assume its a manually-mapped C type, where we can just define an null() fn
1218                                         write!(w, "{}::null()", self.c_type_from_path(&resolved, false, false).unwrap()).unwrap();
1219                                 }
1220                         },
1221                         syn::Type::Array(a) => {
1222                                 if let syn::Expr::Lit(l) = &a.len {
1223                                         if let syn::Lit::Int(i) = &l.lit {
1224                                                 if i.base10_digits().parse::<usize>().unwrap() < 32 {
1225                                                         // Blindly assume that if we're trying to create an empty value for an
1226                                                         // array < 32 entries that all-0s may be a valid state.
1227                                                         unimplemented!();
1228                                                 }
1229                                                 let arrty = format!("[u8; {}]", i.base10_digits());
1230                                                 write!(w, "{}", self.to_c_conversion_inline_prefix_from_path(&arrty, false, false).unwrap()).unwrap();
1231                                                 write!(w, "[0; {}]", i.base10_digits()).unwrap();
1232                                                 write!(w, "{}", self.to_c_conversion_inline_suffix_from_path(&arrty, false, false).unwrap()).unwrap();
1233                                         } else { unimplemented!(); }
1234                                 } else { unimplemented!(); }
1235                         }
1236                         _ => unimplemented!(),
1237                 }
1238         }
1239
1240         /// Prints a suffix to determine if a variable is empty (ie was set by write_empty_rust_val).
1241         /// See EmptyValExpectedTy for information on return types.
1242         fn write_empty_rust_val_check_suffix<W: std::io::Write>(&self, generics: Option<&GenericTypes>, w: &mut W, t: &syn::Type) -> EmptyValExpectedTy {
1243                 match t {
1244                         syn::Type::Path(p) => {
1245                                 let resolved = self.resolve_path(&p.path, generics);
1246                                 if self.crate_types.opaques.get(&resolved).is_some() {
1247                                         write!(w, ".inner.is_null()").unwrap();
1248                                         EmptyValExpectedTy::NonPointer
1249                                 } else {
1250                                         if let Some(suffix) = self.empty_val_check_suffix_from_path(&resolved) {
1251                                                 write!(w, "{}", suffix).unwrap();
1252                                                 // We may eventually need to allow empty_val_check_suffix_from_path to specify if we need a deref or not
1253                                                 EmptyValExpectedTy::NonPointer
1254                                         } else {
1255                                                 write!(w, " == std::ptr::null_mut()").unwrap();
1256                                                 EmptyValExpectedTy::OwnedPointer
1257                                         }
1258                                 }
1259                         },
1260                         syn::Type::Array(a) => {
1261                                 if let syn::Expr::Lit(l) = &a.len {
1262                                         if let syn::Lit::Int(i) = &l.lit {
1263                                                 write!(w, " == [0; {}]", i.base10_digits()).unwrap();
1264                                                 EmptyValExpectedTy::NonPointer
1265                                         } else { unimplemented!(); }
1266                                 } else { unimplemented!(); }
1267                         },
1268                         syn::Type::Slice(_) => {
1269                                 // Option<[]> always implies that we want to treat len() == 0 differently from
1270                                 // None, so we always map an Option<[]> into a pointer.
1271                                 write!(w, " == std::ptr::null_mut()").unwrap();
1272                                 EmptyValExpectedTy::ReferenceAsPointer
1273                         },
1274                         _ => unimplemented!(),
1275                 }
1276         }
1277
1278         /// Prints a suffix to determine if a variable is empty (ie was set by write_empty_rust_val).
1279         pub fn write_empty_rust_val_check<W: std::io::Write>(&self, generics: Option<&GenericTypes>, w: &mut W, t: &syn::Type, var_access: &str) {
1280                 match t {
1281                         syn::Type::Path(_) => {
1282                                 write!(w, "{}", var_access).unwrap();
1283                                 self.write_empty_rust_val_check_suffix(generics, w, t);
1284                         },
1285                         syn::Type::Array(a) => {
1286                                 if let syn::Expr::Lit(l) = &a.len {
1287                                         if let syn::Lit::Int(i) = &l.lit {
1288                                                 let arrty = format!("[u8; {}]", i.base10_digits());
1289                                                 // We don't (yet) support a new-var conversion here.
1290                                                 assert!(self.from_c_conversion_new_var_from_path(&arrty, false).is_none());
1291                                                 write!(w, "{}{}{}",
1292                                                         self.from_c_conversion_prefix_from_path(&arrty, false).unwrap(),
1293                                                         var_access,
1294                                                         self.from_c_conversion_suffix_from_path(&arrty, false).unwrap()).unwrap();
1295                                                 self.write_empty_rust_val_check_suffix(generics, w, t);
1296                                         } else { unimplemented!(); }
1297                                 } else { unimplemented!(); }
1298                         }
1299                         _ => unimplemented!(),
1300                 }
1301         }
1302
1303         // ********************************
1304         // *** Type conversion printing ***
1305         // ********************************
1306
1307         /// Returns true we if can just skip passing this to C entirely
1308         pub fn skip_arg(&self, t: &syn::Type, generics: Option<&GenericTypes>) -> bool {
1309                 match t {
1310                         syn::Type::Path(p) => {
1311                                 if p.qself.is_some() { unimplemented!(); }
1312                                 if let Some(full_path) = self.maybe_resolve_path(&p.path, generics) {
1313                                         self.skip_path(&full_path)
1314                                 } else { false }
1315                         },
1316                         syn::Type::Reference(r) => {
1317                                 self.skip_arg(&*r.elem, generics)
1318                         },
1319                         _ => false,
1320                 }
1321         }
1322         pub fn no_arg_to_rust<W: std::io::Write>(&self, w: &mut W, t: &syn::Type, generics: Option<&GenericTypes>) {
1323                 match t {
1324                         syn::Type::Path(p) => {
1325                                 if p.qself.is_some() { unimplemented!(); }
1326                                 if let Some(full_path) = self.maybe_resolve_path(&p.path, generics) {
1327                                         write!(w, "{}", self.no_arg_path_to_rust(&full_path)).unwrap();
1328                                 }
1329                         },
1330                         syn::Type::Reference(r) => {
1331                                 self.no_arg_to_rust(w, &*r.elem, generics);
1332                         },
1333                         _ => {},
1334                 }
1335         }
1336
1337         fn write_conversion_inline_intern<W: std::io::Write,
1338                         LP: Fn(&str, bool, bool) -> Option<String>, DL: Fn(&mut W, &DeclType, &str, bool, bool), SC: Fn(bool) -> &'static str>
1339                         (&self, w: &mut W, t: &syn::Type, generics: Option<&GenericTypes>, is_ref: bool, is_mut: bool, ptr_for_ref: bool,
1340                          tupleconv: &str, prefix: bool, sliceconv: SC, path_lookup: LP, decl_lookup: DL) {
1341                 match t {
1342                         syn::Type::Reference(r) => {
1343                                 self.write_conversion_inline_intern(w, &*r.elem, generics, true, r.mutability.is_some(),
1344                                         ptr_for_ref, tupleconv, prefix, sliceconv, path_lookup, decl_lookup);
1345                         },
1346                         syn::Type::Path(p) => {
1347                                 if p.qself.is_some() {
1348                                         unimplemented!();
1349                                 }
1350
1351                                 let resolved_path = self.resolve_path(&p.path, generics);
1352                                 if let Some(aliased_type) = self.crate_types.type_aliases.get(&resolved_path) {
1353                                         return self.write_conversion_inline_intern(w, aliased_type, None, is_ref, is_mut, ptr_for_ref, tupleconv, prefix, sliceconv, path_lookup, decl_lookup);
1354                                 } else if let Some(c_type) = path_lookup(&resolved_path, is_ref, ptr_for_ref) {
1355                                         write!(w, "{}", c_type).unwrap();
1356                                 } else if self.crate_types.opaques.get(&resolved_path).is_some() {
1357                                         decl_lookup(w, &DeclType::StructImported, &resolved_path, is_ref, is_mut);
1358                                 } else if self.crate_types.mirrored_enums.get(&resolved_path).is_some() {
1359                                         decl_lookup(w, &DeclType::MirroredEnum, &resolved_path, is_ref, is_mut);
1360                                 } else if let Some(t) = self.crate_types.traits.get(&resolved_path) {
1361                                         decl_lookup(w, &DeclType::Trait(t), &resolved_path, is_ref, is_mut);
1362                                 } else if let Some(ident) = single_ident_generic_path_to_ident(&p.path) {
1363                                         if let Some(decl_type) = self.types.maybe_resolve_declared(ident) {
1364                                                 decl_lookup(w, decl_type, &self.maybe_resolve_ident(ident).unwrap(), is_ref, is_mut);
1365                                         } else { unimplemented!(); }
1366                                 } else { unimplemented!(); }
1367                         },
1368                         syn::Type::Array(a) => {
1369                                 // We assume all arrays contain only [int_literal; X]s.
1370                                 // This may result in some outputs not compiling.
1371                                 if let syn::Expr::Lit(l) = &a.len {
1372                                         if let syn::Lit::Int(i) = &l.lit {
1373                                                 write!(w, "{}", path_lookup(&format!("[u8; {}]", i.base10_digits()), is_ref, ptr_for_ref).unwrap()).unwrap();
1374                                         } else { unimplemented!(); }
1375                                 } else { unimplemented!(); }
1376                         },
1377                         syn::Type::Slice(s) => {
1378                                 // We assume all slices contain only literals or references.
1379                                 // This may result in some outputs not compiling.
1380                                 if let syn::Type::Path(p) = &*s.elem {
1381                                         let resolved = self.resolve_path(&p.path, generics);
1382                                         assert!(self.is_primitive(&resolved));
1383                                         write!(w, "{}", path_lookup("[u8]", is_ref, ptr_for_ref).unwrap()).unwrap();
1384                                 } else if let syn::Type::Reference(r) = &*s.elem {
1385                                         if let syn::Type::Path(p) = &*r.elem {
1386                                                 write!(w, "{}", sliceconv(self.c_type_has_inner_from_path(&self.resolve_path(&p.path, generics)))).unwrap();
1387                                         } else { unimplemented!(); }
1388                                 } else if let syn::Type::Tuple(t) = &*s.elem {
1389                                         assert!(!t.elems.is_empty());
1390                                         if prefix {
1391                                                 write!(w, "&local_").unwrap();
1392                                         } else {
1393                                                 let mut needs_map = false;
1394                                                 for e in t.elems.iter() {
1395                                                         if let syn::Type::Reference(_) = e {
1396                                                                 needs_map = true;
1397                                                         }
1398                                                 }
1399                                                 if needs_map {
1400                                                         write!(w, ".iter().map(|(").unwrap();
1401                                                         for i in 0..t.elems.len() {
1402                                                                 write!(w, "{}{}", if i != 0 { ", " } else { "" }, ('a' as u8 + i as u8) as char).unwrap();
1403                                                         }
1404                                                         write!(w, ")| (").unwrap();
1405                                                         for (idx, e) in t.elems.iter().enumerate() {
1406                                                                 if let syn::Type::Reference(_) = e {
1407                                                                         write!(w, "{}{}", if idx != 0 { ", " } else { "" }, (idx as u8 + 'a' as u8) as char).unwrap();
1408                                                                 } else if let syn::Type::Path(_) = e {
1409                                                                         write!(w, "{}*{}", if idx != 0 { ", " } else { "" }, (idx as u8 + 'a' as u8) as char).unwrap();
1410                                                                 } else { unimplemented!(); }
1411                                                         }
1412                                                         write!(w, ")).collect::<Vec<_>>()[..]").unwrap();
1413                                                 }
1414                                         }
1415                                 } else { unimplemented!(); }
1416                         },
1417                         syn::Type::Tuple(t) => {
1418                                 if t.elems.is_empty() {
1419                                         // cbindgen has poor support for (), see, eg https://github.com/eqrion/cbindgen/issues/527
1420                                         // so work around it by just pretending its a 0u8
1421                                         write!(w, "{}", tupleconv).unwrap();
1422                                 } else {
1423                                         if prefix { write!(w, "local_").unwrap(); }
1424                                 }
1425                         },
1426                         _ => unimplemented!(),
1427                 }
1428         }
1429
1430         fn write_to_c_conversion_inline_prefix_inner<W: std::io::Write>(&self, w: &mut W, t: &syn::Type, generics: Option<&GenericTypes>, is_ref: bool, ptr_for_ref: bool, from_ptr: bool) {
1431                 self.write_conversion_inline_intern(w, t, generics, is_ref, false, ptr_for_ref, "0u8 /*", true, |_| "local_",
1432                                 |a, b, c| self.to_c_conversion_inline_prefix_from_path(a, b, c),
1433                                 |w, decl_type, decl_path, is_ref, _is_mut| {
1434                                         match decl_type {
1435                                                 DeclType::MirroredEnum if is_ref && ptr_for_ref => write!(w, "crate::{}::from_native(&", decl_path).unwrap(),
1436                                                 DeclType::MirroredEnum if is_ref => write!(w, "&crate::{}::from_native(&", decl_path).unwrap(),
1437                                                 DeclType::MirroredEnum => write!(w, "crate::{}::native_into(", decl_path).unwrap(),
1438                                                 DeclType::EnumIgnored|DeclType::StructImported if is_ref && ptr_for_ref && from_ptr =>
1439                                                         write!(w, "crate::{} {{ inner: unsafe {{ (", decl_path).unwrap(),
1440                                                 DeclType::EnumIgnored|DeclType::StructImported if is_ref && ptr_for_ref =>
1441                                                         write!(w, "crate::{} {{ inner: unsafe {{ ( (&(", decl_path).unwrap(),
1442                                                 DeclType::EnumIgnored|DeclType::StructImported if is_ref =>
1443                                                         write!(w, "&crate::{} {{ inner: unsafe {{ (", decl_path).unwrap(),
1444                                                 DeclType::EnumIgnored|DeclType::StructImported if !is_ref && from_ptr =>
1445                                                         write!(w, "crate::{} {{ inner: ", decl_path).unwrap(),
1446                                                 DeclType::EnumIgnored|DeclType::StructImported if !is_ref =>
1447                                                         write!(w, "crate::{} {{ inner: Box::into_raw(Box::new(", decl_path).unwrap(),
1448                                                 DeclType::Trait(_) if is_ref => write!(w, "&").unwrap(),
1449                                                 DeclType::Trait(_) if !is_ref => {},
1450                                                 _ => panic!("{:?}", decl_path),
1451                                         }
1452                                 });
1453         }
1454         pub fn write_to_c_conversion_inline_prefix<W: std::io::Write>(&self, w: &mut W, t: &syn::Type, generics: Option<&GenericTypes>, ptr_for_ref: bool) {
1455                 self.write_to_c_conversion_inline_prefix_inner(w, t, generics, false, ptr_for_ref, false);
1456         }
1457         fn write_to_c_conversion_inline_suffix_inner<W: std::io::Write>(&self, w: &mut W, t: &syn::Type, generics: Option<&GenericTypes>, is_ref: bool, ptr_for_ref: bool, from_ptr: bool) {
1458                 self.write_conversion_inline_intern(w, t, generics, is_ref, false, ptr_for_ref, "*/", false, |_| ".into()",
1459                                 |a, b, c| self.to_c_conversion_inline_suffix_from_path(a, b, c),
1460                                 |w, decl_type, _full_path, is_ref, _is_mut| match decl_type {
1461                                         DeclType::MirroredEnum => write!(w, ")").unwrap(),
1462                                         DeclType::EnumIgnored|DeclType::StructImported if is_ref && ptr_for_ref && from_ptr =>
1463                                                 write!(w, " as *const _) as *mut _ }}, is_owned: false }}").unwrap(),
1464                                         DeclType::EnumIgnored|DeclType::StructImported if is_ref && ptr_for_ref =>
1465                                                 write!(w, ") as *const _) as *mut _) }}, is_owned: false }}").unwrap(),
1466                                         DeclType::EnumIgnored|DeclType::StructImported if is_ref =>
1467                                                 write!(w, " as *const _) as *mut _ }}, is_owned: false }}").unwrap(),
1468                                         DeclType::EnumIgnored|DeclType::StructImported if !is_ref && from_ptr =>
1469                                                 write!(w, ", is_owned: true }}").unwrap(),
1470                                         DeclType::EnumIgnored|DeclType::StructImported if !is_ref => write!(w, ")), is_owned: true }}").unwrap(),
1471                                         DeclType::Trait(_) if is_ref => {},
1472                                         DeclType::Trait(_) => {
1473                                                 // This is used when we're converting a concrete Rust type into a C trait
1474                                                 // for use when a Rust trait method returns an associated type.
1475                                                 // Because all of our C traits implement From<RustTypesImplementingTraits>
1476                                                 // we can just call .into() here and be done.
1477                                                 write!(w, ".into()").unwrap()
1478                                         },
1479                                         _ => unimplemented!(),
1480                                 });
1481         }
1482         pub fn write_to_c_conversion_inline_suffix<W: std::io::Write>(&self, w: &mut W, t: &syn::Type, generics: Option<&GenericTypes>, ptr_for_ref: bool) {
1483                 self.write_to_c_conversion_inline_suffix_inner(w, t, generics, false, ptr_for_ref, false);
1484         }
1485
1486         fn write_from_c_conversion_prefix_inner<W: std::io::Write>(&self, w: &mut W, t: &syn::Type, generics: Option<&GenericTypes>, is_ref: bool, ptr_for_ref: bool) {
1487                 self.write_conversion_inline_intern(w, t, generics, is_ref, false, false, "() /*", true, |_| "&local_",
1488                                 |a, b, _c| self.from_c_conversion_prefix_from_path(a, b),
1489                                 |w, decl_type, _full_path, is_ref, is_mut| match decl_type {
1490                                         DeclType::StructImported if is_ref && ptr_for_ref => write!(w, "unsafe {{ &*(*").unwrap(),
1491                                         DeclType::StructImported if is_mut && is_ref => write!(w, "unsafe {{ &mut *").unwrap(),
1492                                         DeclType::StructImported if is_ref => write!(w, "unsafe {{ &*").unwrap(),
1493                                         DeclType::StructImported if !is_ref => write!(w, "*unsafe {{ Box::from_raw(").unwrap(),
1494                                         DeclType::MirroredEnum if is_ref => write!(w, "&").unwrap(),
1495                                         DeclType::MirroredEnum => {},
1496                                         DeclType::Trait(_) => {},
1497                                         _ => unimplemented!(),
1498                                 });
1499         }
1500         pub fn write_from_c_conversion_prefix<W: std::io::Write>(&self, w: &mut W, t: &syn::Type, generics: Option<&GenericTypes>) {
1501                 self.write_from_c_conversion_prefix_inner(w, t, generics, false, false);
1502         }
1503         fn write_from_c_conversion_suffix_inner<W: std::io::Write>(&self, w: &mut W, t: &syn::Type, generics: Option<&GenericTypes>, is_ref: bool, ptr_for_ref: bool) {
1504                 self.write_conversion_inline_intern(w, t, generics, is_ref, false, false, "*/", false,
1505                                 |has_inner| match has_inner {
1506                                         false => ".iter().collect::<Vec<_>>()[..]",
1507                                         true => "[..]",
1508                                 },
1509                                 |a, b, _c| self.from_c_conversion_suffix_from_path(a, b),
1510                                 |w, decl_type, _full_path, is_ref, _is_mut| match decl_type {
1511                                         DeclType::StructImported if is_ref && ptr_for_ref => write!(w, ").inner }}").unwrap(),
1512                                         DeclType::StructImported if is_ref => write!(w, ".inner }}").unwrap(),
1513                                         DeclType::StructImported if !is_ref => write!(w, ".take_inner()) }}").unwrap(),
1514                                         DeclType::MirroredEnum if is_ref => write!(w, ".to_native()").unwrap(),
1515                                         DeclType::MirroredEnum => write!(w, ".into_native()").unwrap(),
1516                                         DeclType::Trait(_) => {},
1517                                         _ => unimplemented!(),
1518                                 });
1519         }
1520         pub fn write_from_c_conversion_suffix<W: std::io::Write>(&self, w: &mut W, t: &syn::Type, generics: Option<&GenericTypes>) {
1521                 self.write_from_c_conversion_suffix_inner(w, t, generics, false, false);
1522         }
1523         // Note that compared to the above conversion functions, the following two are generally
1524         // significantly undertested:
1525         pub fn write_from_c_conversion_to_ref_prefix<W: std::io::Write>(&self, w: &mut W, t: &syn::Type, generics: Option<&GenericTypes>) {
1526                 self.write_conversion_inline_intern(w, t, generics, false, false, false, "() /*", true, |_| "&local_",
1527                                 |a, b, _c| {
1528                                         if let Some(conv) = self.from_c_conversion_prefix_from_path(a, b) {
1529                                                 Some(format!("&{}", conv))
1530                                         } else { None }
1531                                 },
1532                                 |w, decl_type, _full_path, is_ref, _is_mut| match decl_type {
1533                                         DeclType::StructImported if !is_ref => write!(w, "unsafe {{ &*").unwrap(),
1534                                         _ => unimplemented!(),
1535                                 });
1536         }
1537         pub fn write_from_c_conversion_to_ref_suffix<W: std::io::Write>(&self, w: &mut W, t: &syn::Type, generics: Option<&GenericTypes>) {
1538                 self.write_conversion_inline_intern(w, t, generics, false, false, false, "*/", false,
1539                                 |has_inner| match has_inner {
1540                                         false => ".iter().collect::<Vec<_>>()[..]",
1541                                         true => "[..]",
1542                                 },
1543                                 |a, b, _c| self.from_c_conversion_suffix_from_path(a, b),
1544                                 |w, decl_type, _full_path, is_ref, _is_mut| match decl_type {
1545                                         DeclType::StructImported if !is_ref => write!(w, ".inner }}").unwrap(),
1546                                         _ => unimplemented!(),
1547                                 });
1548         }
1549
1550         fn write_conversion_new_var_intern<'b, W: std::io::Write,
1551                 LP: Fn(&str, bool) -> Option<(&str, &str)>,
1552                 LC: Fn(&str, bool, Option<&syn::Type>, &syn::Ident, &str) ->  Option<(&'b str, Vec<(String, String)>, &'b str)>,
1553                 VP: Fn(&mut W, &syn::Type, Option<&GenericTypes>, bool, bool, bool),
1554                 VS: Fn(&mut W, &syn::Type, Option<&GenericTypes>, bool, bool, bool)>
1555                         (&self, w: &mut W, ident: &syn::Ident, var: &str, t: &syn::Type, generics: Option<&GenericTypes>,
1556                          mut is_ref: bool, mut ptr_for_ref: bool, to_c: bool,
1557                          path_lookup: &LP, container_lookup: &LC, var_prefix: &VP, var_suffix: &VS) -> bool {
1558
1559                 macro_rules! convert_container {
1560                         ($container_type: expr, $args_len: expr, $args_iter: expr) => { {
1561                                 // For slices (and Options), we refuse to directly map them as is_ref when they
1562                                 // aren't opaque types containing an inner pointer. This is due to the fact that,
1563                                 // in both cases, the actual higher-level type is non-is_ref.
1564                                 let ty_has_inner = if self.is_transparent_container(&$container_type, is_ref) || $container_type == "Slice" {
1565                                         let ty = $args_iter().next().unwrap();
1566                                         if $container_type == "Slice" && to_c {
1567                                                 // "To C ptr_for_ref" means "return the regular object with is_owned
1568                                                 // set to false", which is totally what we want in a slice if we're about to
1569                                                 // set ty_has_inner.
1570                                                 ptr_for_ref = true;
1571                                         }
1572                                         if let syn::Type::Reference(t) = ty {
1573                                                 if let syn::Type::Path(p) = &*t.elem {
1574                                                         self.c_type_has_inner_from_path(&self.resolve_path(&p.path, generics))
1575                                                 } else { false }
1576                                         } else if let syn::Type::Path(p) = ty {
1577                                                 self.c_type_has_inner_from_path(&self.resolve_path(&p.path, generics))
1578                                         } else { false }
1579                                 } else { true };
1580
1581                                 // Options get a bunch of special handling, since in general we map Option<>al
1582                                 // types into the same C type as non-Option-wrapped types. This ends up being
1583                                 // pretty manual here and most of the below special-cases are for Options.
1584                                 let mut needs_ref_map = false;
1585                                 let mut only_contained_type = None;
1586                                 let mut only_contained_has_inner = false;
1587                                 let mut contains_slice = false;
1588                                 if $args_len == 1 && self.is_transparent_container(&$container_type, is_ref) {
1589                                         only_contained_has_inner = ty_has_inner;
1590                                         let arg = $args_iter().next().unwrap();
1591                                         if let syn::Type::Reference(t) = arg {
1592                                                 only_contained_type = Some(&*t.elem);
1593                                                 if let syn::Type::Path(_) = &*t.elem {
1594                                                         is_ref = true;
1595                                                 } else if let syn::Type::Slice(_) = &*t.elem {
1596                                                         contains_slice = true;
1597                                                 } else { return false; }
1598                                                 needs_ref_map = true;
1599                                         } else if let syn::Type::Path(_) = arg {
1600                                                 only_contained_type = Some(&arg);
1601                                         } else { unimplemented!(); }
1602                                 }
1603
1604                                 if let Some((prefix, conversions, suffix)) = container_lookup(&$container_type, is_ref && ty_has_inner, only_contained_type, ident, var) {
1605                                         assert_eq!(conversions.len(), $args_len);
1606                                         write!(w, "let mut local_{}{} = ", ident, if !to_c && needs_ref_map {"_base"} else { "" }).unwrap();
1607                                         if only_contained_has_inner && to_c {
1608                                                 var_prefix(w, $args_iter().next().unwrap(), generics, is_ref, ptr_for_ref, true);
1609                                         }
1610                                         write!(w, "{}{}", prefix, var).unwrap();
1611
1612                                         for ((pfx, var_name), (idx, ty)) in conversions.iter().zip($args_iter().enumerate()) {
1613                                                 let mut var = std::io::Cursor::new(Vec::new());
1614                                                 write!(&mut var, "{}", var_name).unwrap();
1615                                                 let var_access = String::from_utf8(var.into_inner()).unwrap();
1616
1617                                                 let conv_ty = if needs_ref_map { only_contained_type.as_ref().unwrap() } else { ty };
1618
1619                                                 write!(w, "{} {{ ", pfx).unwrap();
1620                                                 let new_var_name = format!("{}_{}", ident, idx);
1621                                                 let new_var = self.write_conversion_new_var_intern(w, &syn::Ident::new(&new_var_name, Span::call_site()),
1622                                                                 &var_access, conv_ty, generics, contains_slice || (is_ref && ty_has_inner), ptr_for_ref, to_c, path_lookup, container_lookup, var_prefix, var_suffix);
1623                                                 if new_var { write!(w, " ").unwrap(); }
1624                                                 if (!only_contained_has_inner || !to_c) && !contains_slice {
1625                                                         var_prefix(w, conv_ty, generics, is_ref && ty_has_inner, ptr_for_ref, false);
1626                                                 }
1627
1628                                                 if !is_ref && !needs_ref_map && to_c && only_contained_has_inner {
1629                                                         write!(w, "Box::into_raw(Box::new(").unwrap();
1630                                                 }
1631                                                 write!(w, "{}{}", if contains_slice { "local_" } else { "" }, if new_var { new_var_name } else { var_access }).unwrap();
1632                                                 if (!only_contained_has_inner || !to_c) && !contains_slice {
1633                                                         var_suffix(w, conv_ty, generics, is_ref && ty_has_inner, ptr_for_ref, false);
1634                                                 }
1635                                                 if !is_ref && !needs_ref_map && to_c && only_contained_has_inner {
1636                                                         write!(w, "))").unwrap();
1637                                                 }
1638                                                 write!(w, " }}").unwrap();
1639                                         }
1640                                         write!(w, "{}", suffix).unwrap();
1641                                         if only_contained_has_inner && to_c {
1642                                                 var_suffix(w, $args_iter().next().unwrap(), generics, is_ref, ptr_for_ref, true);
1643                                         }
1644                                         write!(w, ";").unwrap();
1645                                         if !to_c && needs_ref_map {
1646                                                 write!(w, " let mut local_{} = local_{}_base.as_ref()", ident, ident).unwrap();
1647                                                 if contains_slice {
1648                                                         write!(w, ".map(|a| &a[..])").unwrap();
1649                                                 }
1650                                                 write!(w, ";").unwrap();
1651                                         }
1652                                         return true;
1653                                 }
1654                         } }
1655                 }
1656
1657                 match t {
1658                         syn::Type::Reference(r) => {
1659                                 if let syn::Type::Slice(_) = &*r.elem {
1660                                         self.write_conversion_new_var_intern(w, ident, var, &*r.elem, generics, is_ref, ptr_for_ref, to_c, path_lookup, container_lookup, var_prefix, var_suffix)
1661                                 } else {
1662                                         self.write_conversion_new_var_intern(w, ident, var, &*r.elem, generics, true, ptr_for_ref, to_c, path_lookup, container_lookup, var_prefix, var_suffix)
1663                                 }
1664                         },
1665                         syn::Type::Path(p) => {
1666                                 if p.qself.is_some() {
1667                                         unimplemented!();
1668                                 }
1669                                 let resolved_path = self.resolve_path(&p.path, generics);
1670                                 if let Some(aliased_type) = self.crate_types.type_aliases.get(&resolved_path) {
1671                                         return self.write_conversion_new_var_intern(w, ident, var, aliased_type, None, is_ref, ptr_for_ref, to_c, path_lookup, container_lookup, var_prefix, var_suffix);
1672                                 }
1673                                 if self.is_known_container(&resolved_path, is_ref) || self.is_transparent_container(&resolved_path, is_ref) {
1674                                         if let syn::PathArguments::AngleBracketed(args) = &p.path.segments.iter().next().unwrap().arguments {
1675                                                 convert_container!(resolved_path, args.args.len(), || args.args.iter().map(|arg| {
1676                                                         if let syn::GenericArgument::Type(ty) = arg {
1677                                                                 ty
1678                                                         } else { unimplemented!(); }
1679                                                 }));
1680                                         } else { unimplemented!(); }
1681                                 }
1682                                 if self.is_primitive(&resolved_path) {
1683                                         false
1684                                 } else if let Some(ty_ident) = single_ident_generic_path_to_ident(&p.path) {
1685                                         if let Some((prefix, suffix)) = path_lookup(&resolved_path, is_ref) {
1686                                                 write!(w, "let mut local_{} = {}{}{};", ident, prefix, var, suffix).unwrap();
1687                                                 true
1688                                         } else if self.types.maybe_resolve_declared(ty_ident).is_some() {
1689                                                 false
1690                                         } else { false }
1691                                 } else { false }
1692                         },
1693                         syn::Type::Array(_) => {
1694                                 // We assume all arrays contain only primitive types.
1695                                 // This may result in some outputs not compiling.
1696                                 false
1697                         },
1698                         syn::Type::Slice(s) => {
1699                                 if let syn::Type::Path(p) = &*s.elem {
1700                                         let resolved = self.resolve_path(&p.path, generics);
1701                                         assert!(self.is_primitive(&resolved));
1702                                         let slice_path = format!("[{}]", resolved);
1703                                         if let Some((prefix, suffix)) = path_lookup(&slice_path, true) {
1704                                                 write!(w, "let mut local_{} = {}{}{};", ident, prefix, var, suffix).unwrap();
1705                                                 true
1706                                         } else { false }
1707                                 } else if let syn::Type::Reference(ty) = &*s.elem {
1708                                         let tyref = [&*ty.elem];
1709                                         is_ref = true;
1710                                         convert_container!("Slice", 1, || tyref.iter());
1711                                         unimplemented!("convert_container should return true as container_lookup should succeed for slices");
1712                                 } else if let syn::Type::Tuple(t) = &*s.elem {
1713                                         // When mapping into a temporary new var, we need to own all the underlying objects.
1714                                         // Thus, we drop any references inside the tuple and convert with non-reference types.
1715                                         let mut elems = syn::punctuated::Punctuated::new();
1716                                         for elem in t.elems.iter() {
1717                                                 if let syn::Type::Reference(r) = elem {
1718                                                         elems.push((*r.elem).clone());
1719                                                 } else {
1720                                                         elems.push(elem.clone());
1721                                                 }
1722                                         }
1723                                         let ty = [syn::Type::Tuple(syn::TypeTuple {
1724                                                 paren_token: t.paren_token, elems
1725                                         })];
1726                                         is_ref = false;
1727                                         ptr_for_ref = true;
1728                                         convert_container!("Slice", 1, || ty.iter());
1729                                         unimplemented!("convert_container should return true as container_lookup should succeed for slices");
1730                                 } else { unimplemented!() }
1731                         },
1732                         syn::Type::Tuple(t) => {
1733                                 if !t.elems.is_empty() {
1734                                         // We don't (yet) support tuple elements which cannot be converted inline
1735                                         write!(w, "let (").unwrap();
1736                                         for idx in 0..t.elems.len() {
1737                                                 if idx != 0 { write!(w, ", ").unwrap(); }
1738                                                 write!(w, "{} orig_{}_{}", if is_ref { "ref" } else { "mut" }, ident, idx).unwrap();
1739                                         }
1740                                         write!(w, ") = {}{}; ", var, if !to_c { ".to_rust()" } else { "" }).unwrap();
1741                                         // Like other template types, tuples are always mapped as their non-ref
1742                                         // versions for types which have different ref mappings. Thus, we convert to
1743                                         // non-ref versions and handle opaque types with inner pointers manually.
1744                                         for (idx, elem) in t.elems.iter().enumerate() {
1745                                                 if let syn::Type::Path(p) = elem {
1746                                                         let v_name = format!("orig_{}_{}", ident, idx);
1747                                                         let tuple_elem_ident = syn::Ident::new(&v_name, Span::call_site());
1748                                                         if self.write_conversion_new_var_intern(w, &tuple_elem_ident, &v_name, elem, generics,
1749                                                                         false, ptr_for_ref, to_c,
1750                                                                         path_lookup, container_lookup, var_prefix, var_suffix) {
1751                                                                 write!(w, " ").unwrap();
1752                                                                 // Opaque types with inner pointers shouldn't ever create new stack
1753                                                                 // variables, so we don't handle it and just assert that it doesn't
1754                                                                 // here.
1755                                                                 assert!(!self.c_type_has_inner_from_path(&self.resolve_path(&p.path, generics)));
1756                                                         }
1757                                                 }
1758                                         }
1759                                         write!(w, "let mut local_{} = (", ident).unwrap();
1760                                         for (idx, elem) in t.elems.iter().enumerate() {
1761                                                 let ty_has_inner = {
1762                                                                 if to_c {
1763                                                                         // "To C ptr_for_ref" means "return the regular object with
1764                                                                         // is_owned set to false", which is totally what we want
1765                                                                         // if we're about to set ty_has_inner.
1766                                                                         ptr_for_ref = true;
1767                                                                 }
1768                                                                 if let syn::Type::Reference(t) = elem {
1769                                                                         if let syn::Type::Path(p) = &*t.elem {
1770                                                                                 self.c_type_has_inner_from_path(&self.resolve_path(&p.path, generics))
1771                                                                         } else { false }
1772                                                                 } else if let syn::Type::Path(p) = elem {
1773                                                                         self.c_type_has_inner_from_path(&self.resolve_path(&p.path, generics))
1774                                                                 } else { false }
1775                                                         };
1776                                                 if idx != 0 { write!(w, ", ").unwrap(); }
1777                                                 var_prefix(w, elem, generics, is_ref && ty_has_inner, ptr_for_ref, false);
1778                                                 if is_ref && ty_has_inner {
1779                                                         // For ty_has_inner, the regular var_prefix mapping will take a
1780                                                         // reference, so deref once here to make sure we keep the original ref.
1781                                                         write!(w, "*").unwrap();
1782                                                 }
1783                                                 write!(w, "orig_{}_{}", ident, idx).unwrap();
1784                                                 if is_ref && !ty_has_inner {
1785                                                         // If we don't have an inner variable's reference to maintain, just
1786                                                         // hope the type is Clonable and use that.
1787                                                         write!(w, ".clone()").unwrap();
1788                                                 }
1789                                                 var_suffix(w, elem, generics, is_ref && ty_has_inner, ptr_for_ref, false);
1790                                         }
1791                                         write!(w, "){};", if to_c { ".into()" } else { "" }).unwrap();
1792                                         true
1793                                 } else { false }
1794                         },
1795                         _ => unimplemented!(),
1796                 }
1797         }
1798
1799         pub fn write_to_c_conversion_new_var_inner<W: std::io::Write>(&self, w: &mut W, ident: &syn::Ident, var_access: &str, t: &syn::Type, generics: Option<&GenericTypes>, ptr_for_ref: bool) -> bool {
1800                 self.write_conversion_new_var_intern(w, ident, var_access, t, generics, false, ptr_for_ref, true,
1801                         &|a, b| self.to_c_conversion_new_var_from_path(a, b),
1802                         &|a, b, c, d, e| self.to_c_conversion_container_new_var(generics, a, b, c, d, e),
1803                         // We force ptr_for_ref here since we can't generate a ref on one line and use it later
1804                         &|a, b, c, d, e, f| self.write_to_c_conversion_inline_prefix_inner(a, b, c, d, e, f),
1805                         &|a, b, c, d, e, f| self.write_to_c_conversion_inline_suffix_inner(a, b, c, d, e, f))
1806         }
1807         pub fn write_to_c_conversion_new_var<W: std::io::Write>(&self, w: &mut W, ident: &syn::Ident, t: &syn::Type, generics: Option<&GenericTypes>, ptr_for_ref: bool) -> bool {
1808                 self.write_to_c_conversion_new_var_inner(w, ident, &format!("{}", ident), t, generics, ptr_for_ref)
1809         }
1810         pub fn write_from_c_conversion_new_var<W: std::io::Write>(&self, w: &mut W, ident: &syn::Ident, t: &syn::Type, generics: Option<&GenericTypes>) -> bool {
1811                 self.write_conversion_new_var_intern(w, ident, &format!("{}", ident), t, generics, false, false, false,
1812                         &|a, b| self.from_c_conversion_new_var_from_path(a, b),
1813                         &|a, b, c, d, e| self.from_c_conversion_container_new_var(generics, a, b, c, d, e),
1814                         // We force ptr_for_ref here since we can't generate a ref on one line and use it later
1815                         &|a, b, c, d, e, _f| self.write_from_c_conversion_prefix_inner(a, b, c, d, e),
1816                         &|a, b, c, d, e, _f| self.write_from_c_conversion_suffix_inner(a, b, c, d, e))
1817         }
1818
1819         // ******************************************************
1820         // *** C Container Type Equivalent and alias Printing ***
1821         // ******************************************************
1822
1823         fn write_template_generics<'b, W: std::io::Write>(&mut self, w: &mut W, args: &mut dyn Iterator<Item=&'b syn::Type>, generics: Option<&GenericTypes>, is_ref: bool) -> bool {
1824                 assert!(!is_ref); // We don't currently support outer reference types
1825                 for (idx, t) in args.enumerate() {
1826                         if idx != 0 {
1827                                 write!(w, ", ").unwrap();
1828                         }
1829                         if let syn::Type::Reference(r_arg) = t {
1830                                 if !self.write_c_type_intern(w, &*r_arg.elem, generics, false, false, false) { return false; }
1831
1832                                 // While write_c_type_intern, above is correct, we don't want to blindly convert a
1833                                 // reference to something stupid, so check that the container is either opaque or a
1834                                 // predefined type (currently only Transaction).
1835                                 if let syn::Type::Path(p_arg) = &*r_arg.elem {
1836                                         let resolved = self.resolve_path(&p_arg.path, generics);
1837                                         assert!(self.crate_types.opaques.get(&resolved).is_some() ||
1838                                                         self.c_type_from_path(&resolved, true, true).is_some(), "Template generics should be opaque or have a predefined mapping");
1839                                 } else { unimplemented!(); }
1840                         } else {
1841                                 if !self.write_c_type_intern(w, t, generics, false, false, false) { return false; }
1842                         }
1843                 }
1844                 true
1845         }
1846         fn check_create_container(&mut self, mangled_container: String, container_type: &str, args: Vec<&syn::Type>, generics: Option<&GenericTypes>, is_ref: bool) -> bool {
1847                 if !self.crate_types.templates_defined.get(&mangled_container).is_some() {
1848                         let mut created_container: Vec<u8> = Vec::new();
1849
1850                         if container_type == "Result" {
1851                                 let mut a_ty: Vec<u8> = Vec::new();
1852                                 if let syn::Type::Tuple(tup) = args.iter().next().unwrap() {
1853                                         if tup.elems.is_empty() {
1854                                                 write!(&mut a_ty, "()").unwrap();
1855                                         } else {
1856                                                 if !self.write_template_generics(&mut a_ty, &mut args.iter().map(|t| *t).take(1), generics, is_ref) { return false; }
1857                                         }
1858                                 } else {
1859                                         if !self.write_template_generics(&mut a_ty, &mut args.iter().map(|t| *t).take(1), generics, is_ref) { return false; }
1860                                 }
1861
1862                                 let mut b_ty: Vec<u8> = Vec::new();
1863                                 if let syn::Type::Tuple(tup) = args.iter().skip(1).next().unwrap() {
1864                                         if tup.elems.is_empty() {
1865                                                 write!(&mut b_ty, "()").unwrap();
1866                                         } else {
1867                                                 if !self.write_template_generics(&mut b_ty, &mut args.iter().map(|t| *t).skip(1), generics, is_ref) { return false; }
1868                                         }
1869                                 } else {
1870                                         if !self.write_template_generics(&mut b_ty, &mut args.iter().map(|t| *t).skip(1), generics, is_ref) { return false; }
1871                                 }
1872
1873                                 let ok_str = String::from_utf8(a_ty).unwrap();
1874                                 let err_str = String::from_utf8(b_ty).unwrap();
1875                                 let is_clonable = self.is_clonable(&ok_str) && self.is_clonable(&err_str);
1876                                 write_result_block(&mut created_container, &mangled_container, &ok_str, &err_str, is_clonable);
1877                                 if is_clonable {
1878                                         self.crate_types.clonable_types.insert(Self::generated_container_path().to_owned() + "::" + &mangled_container);
1879                                 }
1880                         } else if container_type == "Vec" {
1881                                 let mut a_ty: Vec<u8> = Vec::new();
1882                                 if !self.write_template_generics(&mut a_ty, &mut args.iter().map(|t| *t), generics, is_ref) { return false; }
1883                                 let ty = String::from_utf8(a_ty).unwrap();
1884                                 let is_clonable = self.is_clonable(&ty);
1885                                 write_vec_block(&mut created_container, &mangled_container, &ty, is_clonable);
1886                                 if is_clonable {
1887                                         self.crate_types.clonable_types.insert(Self::generated_container_path().to_owned() + "::" + &mangled_container);
1888                                 }
1889                         } else if container_type.ends_with("Tuple") {
1890                                 let mut tuple_args = Vec::new();
1891                                 let mut is_clonable = true;
1892                                 for arg in args.iter() {
1893                                         let mut ty: Vec<u8> = Vec::new();
1894                                         if !self.write_template_generics(&mut ty, &mut [arg].iter().map(|t| **t), generics, is_ref) { return false; }
1895                                         let ty_str = String::from_utf8(ty).unwrap();
1896                                         if !self.is_clonable(&ty_str) {
1897                                                 is_clonable = false;
1898                                         }
1899                                         tuple_args.push(ty_str);
1900                                 }
1901                                 write_tuple_block(&mut created_container, &mangled_container, &tuple_args, is_clonable);
1902                                 if is_clonable {
1903                                         self.crate_types.clonable_types.insert(Self::generated_container_path().to_owned() + "::" + &mangled_container);
1904                                 }
1905                         } else {
1906                                 unreachable!();
1907                         }
1908                         self.crate_types.templates_defined.insert(mangled_container.clone(), true);
1909
1910                         self.crate_types.template_file.write(&created_container).unwrap();
1911                 }
1912                 true
1913         }
1914         fn path_to_generic_args(path: &syn::Path) -> Vec<&syn::Type> {
1915                 if let syn::PathArguments::AngleBracketed(args) = &path.segments.iter().next().unwrap().arguments {
1916                         args.args.iter().map(|gen| if let syn::GenericArgument::Type(t) = gen { t } else { unimplemented!() }).collect()
1917                 } else { unimplemented!(); }
1918         }
1919         fn write_c_mangled_container_path_intern<W: std::io::Write>
1920                         (&mut self, w: &mut W, args: Vec<&syn::Type>, generics: Option<&GenericTypes>, ident: &str, is_ref: bool, is_mut: bool, ptr_for_ref: bool, in_type: bool) -> bool {
1921                 let mut mangled_type: Vec<u8> = Vec::new();
1922                 if !self.is_transparent_container(ident, is_ref) {
1923                         write!(w, "C{}_", ident).unwrap();
1924                         write!(mangled_type, "C{}_", ident).unwrap();
1925                 } else { assert_eq!(args.len(), 1); }
1926                 for arg in args.iter() {
1927                         macro_rules! write_path {
1928                                 ($p_arg: expr, $extra_write: expr) => {
1929                                         if let Some(subtype) = self.maybe_resolve_path(&$p_arg.path, generics) {
1930                                                 if self.is_transparent_container(ident, is_ref) {
1931                                                         // We dont (yet) support primitives or containers inside transparent
1932                                                         // containers, so check for that first:
1933                                                         if self.is_primitive(&subtype) { return false; }
1934                                                         if self.is_known_container(&subtype, is_ref) { return false; }
1935                                                         if !in_type {
1936                                                                 if self.c_type_has_inner_from_path(&subtype) {
1937                                                                         if !self.write_c_path_intern(w, &$p_arg.path, generics, is_ref, is_mut, ptr_for_ref) { return false; }
1938                                                                 } else {
1939                                                                         // Option<T> needs to be converted to a *mut T, ie mut ptr-for-ref
1940                                                                         if !self.write_c_path_intern(w, &$p_arg.path, generics, true, true, true) { return false; }
1941                                                                 }
1942                                                         } else {
1943                                                                 if $p_arg.path.segments.len() == 1 {
1944                                                                         write!(w, "{}", $p_arg.path.segments.iter().next().unwrap().ident).unwrap();
1945                                                                 } else {
1946                                                                         return false;
1947                                                                 }
1948                                                         }
1949                                                 } else if self.is_known_container(&subtype, is_ref) || self.is_transparent_container(&subtype, is_ref) {
1950                                                         if !self.write_c_mangled_container_path_intern(w, Self::path_to_generic_args(&$p_arg.path), generics,
1951                                                                         &subtype, is_ref, is_mut, ptr_for_ref, true) {
1952                                                                 return false;
1953                                                         }
1954                                                         self.write_c_mangled_container_path_intern(&mut mangled_type, Self::path_to_generic_args(&$p_arg.path),
1955                                                                 generics, &subtype, is_ref, is_mut, ptr_for_ref, true);
1956                                                         if let Some(w2) = $extra_write as Option<&mut Vec<u8>> {
1957                                                                 self.write_c_mangled_container_path_intern(w2, Self::path_to_generic_args(&$p_arg.path),
1958                                                                         generics, &subtype, is_ref, is_mut, ptr_for_ref, true);
1959                                                         }
1960                                                 } else {
1961                                                         let id = subtype.rsplitn(2, ':').next().unwrap(); // Get the "Base" name of the resolved type
1962                                                         write!(w, "{}", id).unwrap();
1963                                                         write!(mangled_type, "{}", id).unwrap();
1964                                                         if let Some(w2) = $extra_write as Option<&mut Vec<u8>> {
1965                                                                 write!(w2, "{}", id).unwrap();
1966                                                         }
1967                                                 }
1968                                         } else { return false; }
1969                                 }
1970                         }
1971                         if let syn::Type::Tuple(tuple) = arg {
1972                                 if tuple.elems.len() == 0 {
1973                                         write!(w, "None").unwrap();
1974                                         write!(mangled_type, "None").unwrap();
1975                                 } else {
1976                                         let mut mangled_tuple_type: Vec<u8> = Vec::new();
1977
1978                                         // Figure out what the mangled type should look like. To disambiguate
1979                                         // ((A, B), C) and (A, B, C) we prefix the generic args with a _ and suffix
1980                                         // them with a Z. Ideally we wouldn't use Z, but not many special chars are
1981                                         // available for use in type names.
1982                                         write!(w, "C{}Tuple_", tuple.elems.len()).unwrap();
1983                                         write!(mangled_type, "C{}Tuple_", tuple.elems.len()).unwrap();
1984                                         write!(mangled_tuple_type, "C{}Tuple_", tuple.elems.len()).unwrap();
1985                                         for elem in tuple.elems.iter() {
1986                                                 if let syn::Type::Path(p) = elem {
1987                                                         write_path!(p, Some(&mut mangled_tuple_type));
1988                                                 } else if let syn::Type::Reference(refelem) = elem {
1989                                                         if let syn::Type::Path(p) = &*refelem.elem {
1990                                                                 write_path!(p, Some(&mut mangled_tuple_type));
1991                                                         } else { return false; }
1992                                                 } else { return false; }
1993                                         }
1994                                         write!(w, "Z").unwrap();
1995                                         write!(mangled_type, "Z").unwrap();
1996                                         write!(mangled_tuple_type, "Z").unwrap();
1997                                         if !self.check_create_container(String::from_utf8(mangled_tuple_type).unwrap(),
1998                                                         &format!("{}Tuple", tuple.elems.len()), tuple.elems.iter().collect(), generics, is_ref) {
1999                                                 return false;
2000                                         }
2001                                 }
2002                         } else if let syn::Type::Path(p_arg) = arg {
2003                                 write_path!(p_arg, None);
2004                         } else if let syn::Type::Reference(refty) = arg {
2005                                 if let syn::Type::Path(p_arg) = &*refty.elem {
2006                                         write_path!(p_arg, None);
2007                                 } else if let syn::Type::Slice(_) = &*refty.elem {
2008                                         // write_c_type will actually do exactly what we want here, we just need to
2009                                         // make it a pointer so that its an option. Note that we cannot always convert
2010                                         // the Vec-as-slice (ie non-ref types) containers, so sometimes need to be able
2011                                         // to edit it, hence we use *mut here instead of *const.
2012                                         if args.len() != 1 { return false; }
2013                                         write!(w, "*mut ").unwrap();
2014                                         self.write_c_type(w, arg, None, true);
2015                                 } else { return false; }
2016                         } else if let syn::Type::Array(a) = arg {
2017                                 if let syn::Type::Path(p_arg) = &*a.elem {
2018                                         let resolved = self.resolve_path(&p_arg.path, generics);
2019                                         if !self.is_primitive(&resolved) { return false; }
2020                                         if let syn::Expr::Lit(syn::ExprLit { lit: syn::Lit::Int(len), .. }) = &a.len {
2021                                                 if self.c_type_from_path(&format!("[{}; {}]", resolved, len.base10_digits()), is_ref, ptr_for_ref).is_none() { return false; }
2022                                                 write!(w, "_{}{}", resolved, len.base10_digits()).unwrap();
2023                                                 write!(mangled_type, "_{}{}", resolved, len.base10_digits()).unwrap();
2024                                         } else { return false; }
2025                                 } else { return false; }
2026                         } else { return false; }
2027                 }
2028                 if self.is_transparent_container(ident, is_ref) { return true; }
2029                 // Push the "end of type" Z
2030                 write!(w, "Z").unwrap();
2031                 write!(mangled_type, "Z").unwrap();
2032
2033                 // Make sure the type is actually defined:
2034                 self.check_create_container(String::from_utf8(mangled_type).unwrap(), ident, args, generics, is_ref)
2035         }
2036         fn write_c_mangled_container_path<W: std::io::Write>(&mut self, w: &mut W, args: Vec<&syn::Type>, generics: Option<&GenericTypes>, ident: &str, is_ref: bool, is_mut: bool, ptr_for_ref: bool) -> bool {
2037                 if !self.is_transparent_container(ident, is_ref) {
2038                         write!(w, "{}::", Self::generated_container_path()).unwrap();
2039                 }
2040                 self.write_c_mangled_container_path_intern(w, args, generics, ident, is_ref, is_mut, ptr_for_ref, false)
2041         }
2042
2043         // **********************************
2044         // *** C Type Equivalent Printing ***
2045         // **********************************
2046
2047         fn write_c_path_intern<W: std::io::Write>(&self, w: &mut W, path: &syn::Path, generics: Option<&GenericTypes>, is_ref: bool, is_mut: bool, ptr_for_ref: bool) -> bool {
2048                 let full_path = match self.maybe_resolve_path(&path, generics) {
2049                         Some(path) => path, None => return false };
2050                 if let Some(c_type) = self.c_type_from_path(&full_path, is_ref, ptr_for_ref) {
2051                         write!(w, "{}", c_type).unwrap();
2052                         true
2053                 } else if self.crate_types.traits.get(&full_path).is_some() {
2054                         if is_ref && ptr_for_ref {
2055                                 write!(w, "*{} crate::{}", if is_mut { "mut" } else { "const" }, full_path).unwrap();
2056                         } else if is_ref {
2057                                 write!(w, "&{}crate::{}", if is_mut { "mut " } else { "" }, full_path).unwrap();
2058                         } else {
2059                                 write!(w, "crate::{}", full_path).unwrap();
2060                         }
2061                         true
2062                 } else if self.crate_types.opaques.get(&full_path).is_some() || self.crate_types.mirrored_enums.get(&full_path).is_some() {
2063                         if is_ref && ptr_for_ref {
2064                                 // ptr_for_ref implies we're returning the object, which we can't really do for
2065                                 // opaque or mirrored types without box'ing them, which is quite a waste, so return
2066                                 // the actual object itself (for opaque types we'll set the pointer to the actual
2067                                 // type and note that its a reference).
2068                                 write!(w, "crate::{}", full_path).unwrap();
2069                         } else if is_ref {
2070                                 write!(w, "&{}crate::{}", if is_mut { "mut " } else { "" }, full_path).unwrap();
2071                         } else {
2072                                 write!(w, "crate::{}", full_path).unwrap();
2073                         }
2074                         true
2075                 } else {
2076                         false
2077                 }
2078         }
2079         fn write_c_type_intern<W: std::io::Write>(&mut self, w: &mut W, t: &syn::Type, generics: Option<&GenericTypes>, is_ref: bool, is_mut: bool, ptr_for_ref: bool) -> bool {
2080                 match t {
2081                         syn::Type::Path(p) => {
2082                                 if p.qself.is_some() {
2083                                         return false;
2084                                 }
2085                                 if let Some(full_path) = self.maybe_resolve_path(&p.path, generics) {
2086                                         if self.is_known_container(&full_path, is_ref) || self.is_transparent_container(&full_path, is_ref) {
2087                                                 return self.write_c_mangled_container_path(w, Self::path_to_generic_args(&p.path), generics, &full_path, is_ref, is_mut, ptr_for_ref);
2088                                         }
2089                                         if let Some(aliased_type) = self.crate_types.type_aliases.get(&full_path).cloned() {
2090                                                 return self.write_c_type_intern(w, &aliased_type, None, is_ref, is_mut, ptr_for_ref);
2091                                         }
2092                                 }
2093                                 self.write_c_path_intern(w, &p.path, generics, is_ref, is_mut, ptr_for_ref)
2094                         },
2095                         syn::Type::Reference(r) => {
2096                                 self.write_c_type_intern(w, &*r.elem, generics, true, r.mutability.is_some(), ptr_for_ref)
2097                         },
2098                         syn::Type::Array(a) => {
2099                                 if is_ref && is_mut {
2100                                         write!(w, "*mut [").unwrap();
2101                                         if !self.write_c_type_intern(w, &a.elem, generics, false, false, ptr_for_ref) { return false; }
2102                                 } else if is_ref {
2103                                         write!(w, "*const [").unwrap();
2104                                         if !self.write_c_type_intern(w, &a.elem, generics, false, false, ptr_for_ref) { return false; }
2105                                 } else {
2106                                         let mut typecheck = Vec::new();
2107                                         if !self.write_c_type_intern(&mut typecheck, &a.elem, generics, false, false, ptr_for_ref) { return false; }
2108                                         if typecheck[..] != ['u' as u8, '8' as u8] { return false; }
2109                                 }
2110                                 if let syn::Expr::Lit(l) = &a.len {
2111                                         if let syn::Lit::Int(i) = &l.lit {
2112                                                 if !is_ref {
2113                                                         if let Some(ty) = self.c_type_from_path(&format!("[u8; {}]", i.base10_digits()), false, ptr_for_ref) {
2114                                                                 write!(w, "{}", ty).unwrap();
2115                                                                 true
2116                                                         } else { false }
2117                                                 } else {
2118                                                         write!(w, "; {}]", i).unwrap();
2119                                                         true
2120                                                 }
2121                                         } else { false }
2122                                 } else { false }
2123                         }
2124                         syn::Type::Slice(s) => {
2125                                 if !is_ref || is_mut { return false; }
2126                                 if let syn::Type::Path(p) = &*s.elem {
2127                                         let resolved = self.resolve_path(&p.path, generics);
2128                                         if self.is_primitive(&resolved) {
2129                                                 write!(w, "{}::{}slice", Self::container_templ_path(), resolved).unwrap();
2130                                                 true
2131                                         } else { false }
2132                                 } else if let syn::Type::Reference(r) = &*s.elem {
2133                                         if let syn::Type::Path(p) = &*r.elem {
2134                                                 // Slices with "real types" inside are mapped as the equivalent non-ref Vec
2135                                                 let resolved = self.resolve_path(&p.path, generics);
2136                                                 let mangled_container = if let Some(ident) = self.crate_types.opaques.get(&resolved) {
2137                                                         format!("CVec_{}Z", ident)
2138                                                 } else if let Some(en) = self.crate_types.mirrored_enums.get(&resolved) {
2139                                                         format!("CVec_{}Z", en.ident)
2140                                                 } else if let Some(id) = p.path.get_ident() {
2141                                                         format!("CVec_{}Z", id)
2142                                                 } else { return false; };
2143                                                 write!(w, "{}::{}", Self::generated_container_path(), mangled_container).unwrap();
2144                                                 self.check_create_container(mangled_container, "Vec", vec![&*r.elem], generics, false)
2145                                         } else { false }
2146                                 } else if let syn::Type::Tuple(_) = &*s.elem {
2147                                         let mut args = syn::punctuated::Punctuated::new();
2148                                         args.push(syn::GenericArgument::Type((*s.elem).clone()));
2149                                         let mut segments = syn::punctuated::Punctuated::new();
2150                                         segments.push(syn::PathSegment {
2151                                                 ident: syn::Ident::new("Vec", Span::call_site()),
2152                                                 arguments: syn::PathArguments::AngleBracketed(syn::AngleBracketedGenericArguments {
2153                                                         colon2_token: None, lt_token: syn::Token![<](Span::call_site()), args, gt_token: syn::Token![>](Span::call_site()),
2154                                                 })
2155                                         });
2156                                         self.write_c_type_intern(w, &syn::Type::Path(syn::TypePath { qself: None, path: syn::Path { leading_colon: None, segments } }), generics, false, is_mut, ptr_for_ref)
2157                                 } else { false }
2158                         },
2159                         syn::Type::Tuple(t) => {
2160                                 if t.elems.len() == 0 {
2161                                         true
2162                                 } else {
2163                                         self.write_c_mangled_container_path(w, t.elems.iter().collect(), generics,
2164                                                 &format!("{}Tuple", t.elems.len()), is_ref, is_mut, ptr_for_ref)
2165                                 }
2166                         },
2167                         _ => false,
2168                 }
2169         }
2170         pub fn write_c_type<W: std::io::Write>(&mut self, w: &mut W, t: &syn::Type, generics: Option<&GenericTypes>, ptr_for_ref: bool) {
2171                 assert!(self.write_c_type_intern(w, t, generics, false, false, ptr_for_ref));
2172         }
2173         pub fn understood_c_path(&mut self, p: &syn::Path) -> bool {
2174                 if p.leading_colon.is_some() { return false; }
2175                 self.write_c_path_intern(&mut std::io::sink(), p, None, false, false, false)
2176         }
2177         pub fn understood_c_type(&mut self, t: &syn::Type, generics: Option<&GenericTypes>) -> bool {
2178                 self.write_c_type_intern(&mut std::io::sink(), t, generics, false, false, false)
2179         }
2180 }