1 use std::collections::HashMap;
5 use proc_macro2::{TokenTree, Span};
7 // The following utils are used purely to build our known types maps - they break down all the
8 // types we need to resolve to include the given object, and no more.
10 pub fn first_seg_self<'a>(t: &'a syn::Type) -> Option<impl Iterator<Item=&syn::PathSegment> + 'a> {
12 syn::Type::Path(p) => {
13 if p.qself.is_some() || p.path.leading_colon.is_some() {
16 let mut segs = p.path.segments.iter();
17 let ty = segs.next().unwrap();
18 if !ty.arguments.is_empty() { return None; }
19 if format!("{}", ty.ident) == "Self" {
27 pub fn get_single_remaining_path_seg<'a, I: Iterator<Item=&'a syn::PathSegment>>(segs: &mut I) -> Option<&'a syn::Ident> {
28 if let Some(ty) = segs.next() {
29 if !ty.arguments.is_empty() { unimplemented!(); }
30 if segs.next().is_some() { return None; }
35 pub fn assert_single_path_seg<'a>(p: &'a syn::Path) -> &'a syn::Ident {
36 if p.leading_colon.is_some() { unimplemented!(); }
37 get_single_remaining_path_seg(&mut p.segments.iter()).unwrap()
40 pub fn single_ident_generic_path_to_ident(p: &syn::Path) -> Option<&syn::Ident> {
41 if p.segments.len() == 1 {
42 Some(&p.segments.iter().next().unwrap().ident)
46 #[derive(Debug, PartialEq)]
47 pub enum ExportStatus {
52 /// Gets the ExportStatus of an object (struct, fn, etc) given its attributes.
53 pub fn export_status(attrs: &[syn::Attribute]) -> ExportStatus {
54 for attr in attrs.iter() {
55 let tokens_clone = attr.tokens.clone();
56 let mut token_iter = tokens_clone.into_iter();
57 if let Some(token) = token_iter.next() {
59 TokenTree::Punct(c) if c.as_char() == '=' => {
60 // Really not sure where syn gets '=' from here -
61 // it somehow represents '///' or '//!'
63 TokenTree::Group(g) => {
64 if format!("{}", single_ident_generic_path_to_ident(&attr.path).unwrap()) == "cfg" {
65 let mut iter = g.stream().into_iter();
66 if let TokenTree::Ident(i) = iter.next().unwrap() {
68 // #[cfg(any(test, feature = ""))]
69 if let TokenTree::Group(g) = iter.next().unwrap() {
70 if let TokenTree::Ident(i) = g.stream().into_iter().next().unwrap() {
71 if i == "test" || i == "feature" {
72 // If its cfg(feature(...)) we assume its test-only
73 return ExportStatus::TestOnly;
77 } else if i == "test" || i == "feature" {
78 // If its cfg(feature(...)) we assume its test-only
79 return ExportStatus::TestOnly;
83 continue; // eg #[derive()]
85 _ => unimplemented!(),
88 match token_iter.next().unwrap() {
89 TokenTree::Literal(lit) => {
90 let line = format!("{}", lit);
91 if line.contains("(C-not exported)") {
92 return ExportStatus::NoExport;
95 _ => unimplemented!(),
101 pub fn assert_simple_bound(bound: &syn::TraitBound) {
102 if bound.paren_token.is_some() || bound.lifetimes.is_some() { unimplemented!(); }
103 if let syn::TraitBoundModifier::Maybe(_) = bound.modifier { unimplemented!(); }
106 /// A stack of sets of generic resolutions.
108 /// This tracks the template parameters for a function, struct, or trait, allowing resolution into
109 /// a concrete type. By pushing a new context onto the stack, this can track a function's template
110 /// parameters inside of a generic struct or trait.
112 /// It maps both direct types as well as Deref<Target = X>, mapping them via the provided
113 /// TypeResolver's resolve_path function (ie traits map to the concrete jump table, structs to the
114 /// concrete C container struct, etc).
115 pub struct GenericTypes<'a> {
116 typed_generics: Vec<HashMap<&'a syn::Ident, (String, Option<&'a syn::Path>)>>,
118 impl<'a> GenericTypes<'a> {
119 pub fn new() -> Self {
120 Self { typed_generics: vec![HashMap::new()], }
123 /// push a new context onto the stack, allowing for a new set of generics to be learned which
124 /// will override any lower contexts, but which will still fall back to resoltion via lower
126 pub fn push_ctx(&mut self) {
127 self.typed_generics.push(HashMap::new());
129 /// pop the latest context off the stack.
130 pub fn pop_ctx(&mut self) {
131 self.typed_generics.pop();
134 /// Learn the generics in generics in the current context, given a TypeResolver.
135 pub fn learn_generics<'b, 'c>(&mut self, generics: &'a syn::Generics, types: &'b TypeResolver<'a, 'c>) -> bool {
136 for generic in generics.params.iter() {
138 syn::GenericParam::Type(type_param) => {
139 let mut non_lifetimes_processed = false;
140 for bound in type_param.bounds.iter() {
141 if let syn::TypeParamBound::Trait(trait_bound) = bound {
142 if let Some(ident) = single_ident_generic_path_to_ident(&trait_bound.path) {
143 match &format!("{}", ident) as &str { "Send" => continue, "Sync" => continue, _ => {} }
146 assert_simple_bound(&trait_bound);
147 if let Some(mut path) = types.maybe_resolve_path(&trait_bound.path, None) {
148 if types.skip_path(&path) { continue; }
149 if non_lifetimes_processed { return false; }
150 non_lifetimes_processed = true;
151 let new_ident = if path != "std::ops::Deref" {
152 path = "crate::".to_string() + &path;
153 Some(&trait_bound.path)
155 self.typed_generics.last_mut().unwrap().insert(&type_param.ident, (path, new_ident));
156 } else { return false; }
163 if let Some(wh) = &generics.where_clause {
164 for pred in wh.predicates.iter() {
165 if let syn::WherePredicate::Type(t) = pred {
166 if let syn::Type::Path(p) = &t.bounded_ty {
167 if p.qself.is_some() { return false; }
168 if p.path.leading_colon.is_some() { return false; }
169 let mut p_iter = p.path.segments.iter();
170 if let Some(gen) = self.typed_generics.last_mut().unwrap().get_mut(&p_iter.next().unwrap().ident) {
171 if gen.0 != "std::ops::Deref" { return false; }
172 if &format!("{}", p_iter.next().unwrap().ident) != "Target" { return false; }
174 let mut non_lifetimes_processed = false;
175 for bound in t.bounds.iter() {
176 if let syn::TypeParamBound::Trait(trait_bound) = bound {
177 if non_lifetimes_processed { return false; }
178 non_lifetimes_processed = true;
179 assert_simple_bound(&trait_bound);
180 *gen = ("crate::".to_string() + &types.resolve_path(&trait_bound.path, None),
181 Some(&trait_bound.path));
184 } else { return false; }
185 } else { return false; }
189 for (_, (_, ident)) in self.typed_generics.last().unwrap().iter() {
190 if ident.is_none() { return false; }
195 /// Attempt to resolve an Ident as a generic parameter and return the full path.
196 pub fn maybe_resolve_ident<'b>(&'b self, ident: &syn::Ident) -> Option<&'b String> {
197 for gen in self.typed_generics.iter().rev() {
198 if let Some(res) = gen.get(ident).map(|(a, _)| a) {
204 /// Attempt to resolve a Path as a generic parameter and return the full path. as both a string
206 pub fn maybe_resolve_path<'b>(&'b self, path: &syn::Path) -> Option<(&'b String, &'a syn::Path)> {
207 if let Some(ident) = path.get_ident() {
208 for gen in self.typed_generics.iter().rev() {
209 if let Some(res) = gen.get(ident).map(|(a, b)| (a, b.unwrap())) {
218 #[derive(Clone, PartialEq)]
219 // The type of declaration and the object itself
220 pub enum DeclType<'a> {
222 Trait(&'a syn::ItemTrait),
228 /// Top-level struct tracking everything which has been defined while walking the crate.
229 pub struct CrateTypes<'a> {
230 /// This may contain structs or enums, but only when either is mapped as
231 /// struct X { inner: *mut originalX, .. }
232 pub opaques: HashMap<String, &'a syn::Ident>,
233 /// Enums which are mapped as C enums with conversion functions
234 pub mirrored_enums: HashMap<String, &'a syn::ItemEnum>,
235 /// Traits which are mapped as a pointer + jump table
236 pub traits: HashMap<String, &'a syn::ItemTrait>,
237 /// Template continer types defined, map from mangled type name -> whether a destructor fn
240 /// This is used at the end of processing to make C++ wrapper classes
241 pub templates_defined: HashMap<String, bool>,
242 /// The output file for any created template container types, written to as we find new
243 /// template containers which need to be defined.
244 pub template_file: &'a mut File,
247 /// A struct which tracks resolving rust types into C-mapped equivalents, exists for one specific
248 /// module but contains a reference to the overall CrateTypes tracking.
249 pub struct TypeResolver<'mod_lifetime, 'crate_lft: 'mod_lifetime> {
250 pub orig_crate: &'mod_lifetime str,
251 pub module_path: &'mod_lifetime str,
252 imports: HashMap<syn::Ident, String>,
253 // ident -> is-mirrored-enum
254 declared: HashMap<syn::Ident, DeclType<'crate_lft>>,
255 pub crate_types: &'mod_lifetime mut CrateTypes<'crate_lft>,
258 impl<'a, 'c: 'a> TypeResolver<'a, 'c> {
259 pub fn new(orig_crate: &'a str, module_path: &'a str, crate_types: &'a mut CrateTypes<'c>) -> Self {
260 let mut imports = HashMap::new();
261 // Add primitives to the "imports" list:
262 imports.insert(syn::Ident::new("bool", Span::call_site()), "bool".to_string());
263 imports.insert(syn::Ident::new("u64", Span::call_site()), "u64".to_string());
264 imports.insert(syn::Ident::new("u32", Span::call_site()), "u32".to_string());
265 imports.insert(syn::Ident::new("u16", Span::call_site()), "u16".to_string());
266 imports.insert(syn::Ident::new("u8", Span::call_site()), "u8".to_string());
267 imports.insert(syn::Ident::new("usize", Span::call_site()), "usize".to_string());
268 imports.insert(syn::Ident::new("str", Span::call_site()), "str".to_string());
269 imports.insert(syn::Ident::new("String", Span::call_site()), "String".to_string());
271 // These are here to allow us to print native Rust types in trait fn impls even if we don't
273 imports.insert(syn::Ident::new("Result", Span::call_site()), "Result".to_string());
274 imports.insert(syn::Ident::new("Vec", Span::call_site()), "Vec".to_string());
275 imports.insert(syn::Ident::new("Option", Span::call_site()), "Option".to_string());
276 Self { orig_crate, module_path, imports, declared: HashMap::new(), crate_types }
279 // *************************************************
280 // *** Well know type and conversion definitions ***
281 // *************************************************
283 /// Returns true we if can just skip passing this to C entirely
284 fn skip_path(&self, full_path: &str) -> bool {
285 full_path == "bitcoin::secp256k1::Secp256k1" ||
286 full_path == "bitcoin::secp256k1::Signing" ||
287 full_path == "bitcoin::secp256k1::Verification"
289 /// Returns true we if can just skip passing this to C entirely
290 fn no_arg_path_to_rust(&self, full_path: &str) -> &str {
291 if full_path == "bitcoin::secp256k1::Secp256k1" {
292 "&bitcoin::secp256k1::Secp256k1::new()"
293 } else { unimplemented!(); }
296 /// Returns true if the object is a primitive and is mapped as-is with no conversion
298 pub fn is_primitive(&self, full_path: &str) -> bool {
309 /// Gets the C-mapped type for types which are outside of the crate, or which are manually
310 /// ignored by for some reason need mapping anyway.
311 fn c_type_from_path<'b>(&self, full_path: &'b str, is_ref: bool, ptr_for_ref: bool) -> Option<&'b str> {
312 if self.is_primitive(full_path) {
313 return Some(full_path);
316 "Result" => Some("crate::c_types::derived::CResult"),
317 "Vec" if !is_ref => Some("crate::c_types::derived::CVec"),
318 "Option" => Some(""),
320 // Note that no !is_ref types can map to an array because Rust and C's call semantics
321 // for arrays are different (https://github.com/eqrion/cbindgen/issues/528)
323 "[u8; 32]" if !is_ref => Some("crate::c_types::ThirtyTwoBytes"),
324 "[u8; 16]" if !is_ref => Some("crate::c_types::SixteenBytes"),
325 "[u8; 10]" if !is_ref => Some("crate::c_types::TenBytes"),
326 "[u8; 4]" if !is_ref => Some("crate::c_types::FourBytes"),
327 "[u8; 3]" if !is_ref => Some("crate::c_types::ThreeBytes"), // Used for RGB values
329 "str" if is_ref => Some("crate::c_types::Str"),
330 "String" if !is_ref => Some("crate::c_types::derived::CVec_u8Z"),
331 "String" if is_ref => Some("crate::c_types::Str"),
333 "std::time::Duration" => Some("u64"),
335 "bitcoin::secp256k1::key::PublicKey" => Some("crate::c_types::PublicKey"),
336 "bitcoin::secp256k1::Signature" => Some("crate::c_types::Signature"),
337 "bitcoin::secp256k1::key::SecretKey" if is_ref => Some("*const [u8; 32]"),
338 "bitcoin::secp256k1::key::SecretKey" if !is_ref => Some("crate::c_types::SecretKey"),
339 "bitcoin::secp256k1::Error" if !is_ref => Some("crate::c_types::Secp256k1Error"),
340 "bitcoin::blockdata::script::Script" if is_ref => Some("crate::c_types::u8slice"),
341 "bitcoin::blockdata::script::Script" if !is_ref => Some("crate::c_types::derived::CVec_u8Z"),
342 "bitcoin::blockdata::transaction::OutPoint" if is_ref => Some("crate::chain::transaction::OutPoint"),
343 "bitcoin::blockdata::transaction::Transaction" if is_ref && !ptr_for_ref => Some("crate::c_types::Transaction"),
344 "bitcoin::blockdata::transaction::Transaction" => Some("crate::c_types::derived::CVec_u8Z"),
345 "bitcoin::blockdata::transaction::TxOut" if !is_ref => Some("crate::c_types::TxOut"),
346 "bitcoin::OutPoint" => Some("crate::chain::transaction::OutPoint"),
347 "bitcoin::network::constants::Network" => Some("crate::bitcoin::network::Network"),
348 "bitcoin::blockdata::block::BlockHeader" if is_ref => Some("*const [u8; 80]"),
349 "bitcoin::blockdata::block::Block" if is_ref => Some("crate::c_types::u8slice"),
351 // Newtypes that we just expose in their original form.
352 "bitcoin::hash_types::Txid" if is_ref => Some("*const [u8; 32]"),
353 "bitcoin::hash_types::Txid" if !is_ref => Some("crate::c_types::ThirtyTwoBytes"),
354 "bitcoin::hash_types::BlockHash" if is_ref => Some("*const [u8; 32]"),
355 "bitcoin::hash_types::BlockHash" if !is_ref => Some("crate::c_types::ThirtyTwoBytes"),
356 "ln::channelmanager::PaymentHash" if is_ref => Some("*const [u8; 32]"),
357 "ln::channelmanager::PaymentHash" if !is_ref => Some("crate::c_types::ThirtyTwoBytes"),
358 "ln::channelmanager::PaymentPreimage" if is_ref => Some("*const [u8; 32]"),
359 "ln::channelmanager::PaymentPreimage" if !is_ref => Some("crate::c_types::ThirtyTwoBytes"),
360 "ln::channelmanager::PaymentSecret" if is_ref => Some("crate::c_types::ThirtyTwoBytes"),
361 "ln::channelmanager::PaymentSecret" if !is_ref => Some("crate::c_types::ThirtyTwoBytes"),
363 // Override the default since Records contain an fmt with a lifetime:
364 "util::logger::Record" => Some("*const std::os::raw::c_char"),
366 // List of structs we map that aren't detected:
367 "ln::features::InitFeatures" if is_ref && ptr_for_ref => Some("crate::ln::features::InitFeatures"),
368 "ln::features::InitFeatures" if is_ref => Some("*const crate::ln::features::InitFeatures"),
369 "ln::features::InitFeatures" => Some("crate::ln::features::InitFeatures"),
371 eprintln!(" Type {} (ref: {}) unresolvable in C", full_path, is_ref);
377 fn from_c_conversion_new_var_from_path<'b>(&self, _full_path: &str, _is_ref: bool) -> Option<(&'b str, &'b str)> {
380 fn from_c_conversion_prefix_from_path<'b>(&self, full_path: &str, is_ref: bool) -> Option<String> {
381 if self.is_primitive(full_path) {
382 return Some("".to_owned());
385 "Vec" if !is_ref => Some("local_"),
386 "Result" if !is_ref => Some("local_"),
387 "Option" if is_ref => Some("&local_"),
388 "Option" => Some("local_"),
390 "[u8; 32]" if is_ref => Some("unsafe { &*"),
391 "[u8; 32]" if !is_ref => Some(""),
392 "[u8; 16]" if !is_ref => Some(""),
393 "[u8; 10]" if !is_ref => Some(""),
394 "[u8; 4]" if !is_ref => Some(""),
395 "[u8; 3]" if !is_ref => Some(""),
397 "[u8]" if is_ref => Some(""),
398 "[usize]" if is_ref => Some(""),
400 "str" if is_ref => Some(""),
401 "String" if !is_ref => Some("String::from_utf8("),
402 // Note that we'll panic for String if is_ref, as we only have non-owned memory, we
403 // cannot create a &String.
405 "std::time::Duration" => Some("std::time::Duration::from_secs("),
407 "bitcoin::secp256k1::key::PublicKey" if is_ref => Some("&"),
408 "bitcoin::secp256k1::key::PublicKey" => Some(""),
409 "bitcoin::secp256k1::Signature" if is_ref => Some("&"),
410 "bitcoin::secp256k1::Signature" => Some(""),
411 "bitcoin::secp256k1::key::SecretKey" if is_ref => Some("&::bitcoin::secp256k1::key::SecretKey::from_slice(&unsafe { *"),
412 "bitcoin::secp256k1::key::SecretKey" if !is_ref => Some(""),
413 "bitcoin::blockdata::script::Script" if is_ref => Some("&::bitcoin::blockdata::script::Script::from(Vec::from("),
414 "bitcoin::blockdata::script::Script" if !is_ref => Some("::bitcoin::blockdata::script::Script::from("),
415 "bitcoin::blockdata::transaction::Transaction" if is_ref => Some("&"),
416 "bitcoin::blockdata::transaction::Transaction" => Some("::bitcoin::consensus::encode::deserialize(&"),
417 "bitcoin::blockdata::transaction::TxOut" if !is_ref => Some(""),
418 "bitcoin::network::constants::Network" => Some(""),
419 "bitcoin::blockdata::block::BlockHeader" => Some("&::bitcoin::consensus::encode::deserialize(unsafe { &*"),
420 "bitcoin::blockdata::block::Block" if is_ref => Some("&::bitcoin::consensus::encode::deserialize("),
422 // Newtypes that we just expose in their original form.
423 "bitcoin::hash_types::Txid" if is_ref => Some("&::bitcoin::hash_types::Txid::from_slice(&unsafe { &*"),
424 "bitcoin::hash_types::Txid" if !is_ref => Some("::bitcoin::hash_types::Txid::from_slice(&"),
425 "bitcoin::hash_types::BlockHash" => Some("::bitcoin::hash_types::BlockHash::from_slice(&"),
426 "ln::channelmanager::PaymentHash" if !is_ref => Some("::lightning::ln::channelmanager::PaymentHash("),
427 "ln::channelmanager::PaymentHash" if is_ref => Some("&::lightning::ln::channelmanager::PaymentHash(unsafe { *"),
428 "ln::channelmanager::PaymentPreimage" if !is_ref => Some("::lightning::ln::channelmanager::PaymentPreimage("),
429 "ln::channelmanager::PaymentPreimage" if is_ref => Some("&::lightning::ln::channelmanager::PaymentPreimage(unsafe { *"),
430 "ln::channelmanager::PaymentSecret" => Some("::lightning::ln::channelmanager::PaymentSecret("),
432 // List of structs we map (possibly during processing of other files):
433 "ln::features::InitFeatures" if !is_ref => Some("*unsafe { Box::from_raw("),
435 // List of traits we map (possibly during processing of other files):
436 "crate::util::logger::Logger" => Some(""),
439 eprintln!(" Type {} unconvertable from C", full_path);
442 }.map(|s| s.to_owned())
444 fn from_c_conversion_suffix_from_path<'b>(&self, full_path: &str, is_ref: bool) -> Option<String> {
445 if self.is_primitive(full_path) {
446 return Some("".to_owned());
449 "Vec" if !is_ref => Some(""),
450 "Option" => Some(""),
451 "Result" if !is_ref => Some(""),
453 "[u8; 32]" if is_ref => Some("}"),
454 "[u8; 32]" if !is_ref => Some(".data"),
455 "[u8; 16]" if !is_ref => Some(".data"),
456 "[u8; 10]" if !is_ref => Some(".data"),
457 "[u8; 4]" if !is_ref => Some(".data"),
458 "[u8; 3]" if !is_ref => Some(".data"),
460 "[u8]" if is_ref => Some(".to_slice()"),
461 "[usize]" if is_ref => Some(".to_slice()"),
463 "str" if is_ref => Some(".into()"),
464 "String" if !is_ref => Some(".into_rust()).unwrap()"),
466 "std::time::Duration" => Some(")"),
468 "bitcoin::secp256k1::key::PublicKey" => Some(".into_rust()"),
469 "bitcoin::secp256k1::Signature" => Some(".into_rust()"),
470 "bitcoin::secp256k1::key::SecretKey" if !is_ref => Some(".into_rust()"),
471 "bitcoin::secp256k1::key::SecretKey" if is_ref => Some("}[..]).unwrap()"),
472 "bitcoin::blockdata::script::Script" if is_ref => Some(".to_slice()))"),
473 "bitcoin::blockdata::script::Script" if !is_ref => Some(".into_rust())"),
474 "bitcoin::blockdata::transaction::Transaction" if is_ref => Some(".into_bitcoin()"),
475 "bitcoin::blockdata::transaction::Transaction" => Some(".into_rust()[..]).unwrap()"),
476 "bitcoin::blockdata::transaction::TxOut" if !is_ref => Some(".into_rust()"),
477 "bitcoin::network::constants::Network" => Some(".into_bitcoin()"),
478 "bitcoin::blockdata::block::BlockHeader" => Some(" }).unwrap()"),
479 "bitcoin::blockdata::block::Block" => Some(".to_slice()).unwrap()"),
481 // Newtypes that we just expose in their original form.
482 "bitcoin::hash_types::Txid" if is_ref => Some(" }[..]).unwrap()"),
483 "bitcoin::hash_types::Txid" => Some(".data[..]).unwrap()"),
484 "bitcoin::hash_types::BlockHash" if !is_ref => Some(".data[..]).unwrap()"),
485 "ln::channelmanager::PaymentHash" if !is_ref => Some(".data)"),
486 "ln::channelmanager::PaymentHash" if is_ref => Some(" })"),
487 "ln::channelmanager::PaymentPreimage" if !is_ref => Some(".data)"),
488 "ln::channelmanager::PaymentPreimage" if is_ref => Some(" })"),
489 "ln::channelmanager::PaymentSecret" => Some(".data)"),
491 // List of structs we map (possibly during processing of other files):
492 "ln::features::InitFeatures" if is_ref => Some(".inner) }"),
493 "ln::features::InitFeatures" if !is_ref => Some(".take_ptr()) }"),
495 // List of traits we map (possibly during processing of other files):
496 "crate::util::logger::Logger" => Some(""),
499 eprintln!(" Type {} unconvertable from C", full_path);
502 }.map(|s| s.to_owned())
505 fn to_c_conversion_new_var_from_path<'b>(&self, full_path: &str, is_ref: bool) -> Option<(&'b str, &'b str)> {
506 if self.is_primitive(full_path) {
510 "[u8]" if is_ref => Some(("crate::c_types::u8slice::from_slice(", ")")),
511 "[usize]" if is_ref => Some(("crate::c_types::usizeslice::from_slice(", ")")),
513 "bitcoin::blockdata::transaction::Transaction" if is_ref => Some(("::bitcoin::consensus::encode::serialize(", ")")),
514 "bitcoin::blockdata::transaction::Transaction" if !is_ref => Some(("::bitcoin::consensus::encode::serialize(&", ")")),
515 "bitcoin::blockdata::block::BlockHeader" if is_ref => Some(("{ let mut s = [0u8; 80]; s[..].copy_from_slice(&::bitcoin::consensus::encode::serialize(", ")); s }")),
516 "bitcoin::blockdata::block::Block" if is_ref => Some(("::bitcoin::consensus::encode::serialize(", ")")),
517 "bitcoin::hash_types::Txid" => None,
519 // Override the default since Records contain an fmt with a lifetime:
520 // TODO: We should include the other record fields
521 "util::logger::Record" => Some(("std::ffi::CString::new(format!(\"{}\", ", ".args)).unwrap()")),
523 }.map(|s| s.to_owned())
525 fn to_c_conversion_inline_prefix_from_path(&self, full_path: &str, is_ref: bool, ptr_for_ref: bool) -> Option<String> {
526 if self.is_primitive(full_path) {
527 return Some("".to_owned());
530 "Result" if !is_ref => Some("local_"),
531 "Vec" if !is_ref => Some("local_"),
532 "Option" => Some("local_"),
534 "[u8; 32]" if !is_ref => Some("crate::c_types::ThirtyTwoBytes { data: "),
535 "[u8; 32]" if is_ref => Some("&"),
536 "[u8; 16]" if !is_ref => Some("crate::c_types::SixteenBytes { data: "),
537 "[u8; 10]" if !is_ref => Some("crate::c_types::TenBytes { data: "),
538 "[u8; 4]" if !is_ref => Some("crate::c_types::FourBytes { data: "),
539 "[u8; 3]" if is_ref => Some("&"),
541 "[u8]" if is_ref => Some("local_"),
542 "[usize]" if is_ref => Some("local_"),
544 "str" if is_ref => Some(""),
545 "String" => Some(""),
547 "std::time::Duration" => Some(""),
549 "bitcoin::secp256k1::key::PublicKey" => Some("crate::c_types::PublicKey::from_rust(&"),
550 "bitcoin::secp256k1::Signature" => Some("crate::c_types::Signature::from_rust(&"),
551 "bitcoin::secp256k1::key::SecretKey" if is_ref => Some(""),
552 "bitcoin::secp256k1::key::SecretKey" if !is_ref => Some("crate::c_types::SecretKey::from_rust("),
553 "bitcoin::secp256k1::Error" if !is_ref => Some("crate::c_types::Secp256k1Error::from_rust("),
554 "bitcoin::blockdata::script::Script" if is_ref => Some("crate::c_types::u8slice::from_slice(&"),
555 "bitcoin::blockdata::script::Script" if !is_ref => Some(""),
556 "bitcoin::blockdata::transaction::Transaction" if is_ref && !ptr_for_ref => Some("crate::c_types::Transaction::from_slice(&local_"),
557 "bitcoin::blockdata::transaction::Transaction" => Some("local_"),
558 "bitcoin::blockdata::transaction::TxOut" if !is_ref => Some("crate::c_types::TxOut::from_rust("),
559 "bitcoin::blockdata::block::BlockHeader" if is_ref => Some("&local_"),
560 "bitcoin::blockdata::block::Block" if is_ref => Some("crate::c_types::u8slice::from_slice(&local_"),
562 "bitcoin::hash_types::Txid" if !is_ref => Some("crate::c_types::ThirtyTwoBytes { data: "),
564 // Newtypes that we just expose in their original form.
565 "bitcoin::hash_types::Txid" if is_ref => Some(""),
566 "bitcoin::hash_types::BlockHash" if is_ref => Some(""),
567 "bitcoin::hash_types::BlockHash" => Some("crate::c_types::ThirtyTwoBytes { data: "),
568 "ln::channelmanager::PaymentHash" if is_ref => Some("&"),
569 "ln::channelmanager::PaymentHash" if !is_ref => Some("crate::c_types::ThirtyTwoBytes { data: "),
570 "ln::channelmanager::PaymentPreimage" if is_ref => Some("&"),
571 "ln::channelmanager::PaymentPreimage" => Some("crate::c_types::ThirtyTwoBytes { data: "),
572 "ln::channelmanager::PaymentSecret" if !is_ref => Some("crate::c_types::ThirtyTwoBytes { data: "),
574 // Override the default since Records contain an fmt with a lifetime:
575 "util::logger::Record" => Some("local_"),
577 // List of structs we map (possibly during processing of other files):
578 "ln::features::InitFeatures" if is_ref && ptr_for_ref => Some("crate::ln::features::InitFeatures { inner: &mut "),
579 "ln::features::InitFeatures" if is_ref => Some("Box::into_raw(Box::new(crate::ln::features::InitFeatures { inner: &mut "),
580 "ln::features::InitFeatures" if !is_ref => Some("crate::ln::features::InitFeatures { inner: Box::into_raw(Box::new("),
583 eprintln!(" Type {} (is_ref: {}) unconvertable to C", full_path, is_ref);
586 }.map(|s| s.to_owned())
588 fn to_c_conversion_inline_suffix_from_path(&self, full_path: &str, is_ref: bool, ptr_for_ref: bool) -> Option<String> {
589 if self.is_primitive(full_path) {
590 return Some("".to_owned());
593 "Result" if !is_ref => Some(""),
594 "Vec" if !is_ref => Some(".into()"),
595 "Option" => Some(""),
597 "[u8; 32]" if !is_ref => Some(" }"),
598 "[u8; 32]" if is_ref => Some(""),
599 "[u8; 16]" if !is_ref => Some(" }"),
600 "[u8; 10]" if !is_ref => Some(" }"),
601 "[u8; 4]" if !is_ref => Some(" }"),
602 "[u8; 3]" if is_ref => Some(""),
604 "[u8]" if is_ref => Some(""),
605 "[usize]" if is_ref => Some(""),
607 "str" if is_ref => Some(".into()"),
608 "String" if !is_ref => Some(".into_bytes().into()"),
609 "String" if is_ref => Some(".as_str().into()"),
611 "std::time::Duration" => Some(".as_secs()"),
613 "bitcoin::secp256k1::key::PublicKey" => Some(")"),
614 "bitcoin::secp256k1::Signature" => Some(")"),
615 "bitcoin::secp256k1::key::SecretKey" if !is_ref => Some(")"),
616 "bitcoin::secp256k1::key::SecretKey" if is_ref => Some(".as_ref()"),
617 "bitcoin::secp256k1::Error" if !is_ref => Some(")"),
618 "bitcoin::blockdata::script::Script" if is_ref => Some("[..])"),
619 "bitcoin::blockdata::script::Script" if !is_ref => Some(".into_bytes().into()"),
620 "bitcoin::blockdata::transaction::Transaction" if is_ref && !ptr_for_ref => Some(")"),
621 "bitcoin::blockdata::transaction::Transaction" => Some(".into()"),
622 "bitcoin::blockdata::transaction::TxOut" if !is_ref => Some(")"),
623 "bitcoin::blockdata::block::BlockHeader" if is_ref => Some(""),
624 "bitcoin::blockdata::block::Block" if is_ref => Some(")"),
626 "bitcoin::hash_types::Txid" if !is_ref => Some(".into_inner() }"),
628 // Newtypes that we just expose in their original form.
629 "bitcoin::hash_types::Txid" if is_ref => Some(".as_inner()"),
630 "bitcoin::hash_types::BlockHash" if is_ref => Some(".as_inner()"),
631 "bitcoin::hash_types::BlockHash" => Some(".into_inner() }"),
632 "ln::channelmanager::PaymentHash" if is_ref => Some(".0"),
633 "ln::channelmanager::PaymentHash" => Some(".0 }"),
634 "ln::channelmanager::PaymentPreimage" if is_ref => Some(".0"),
635 "ln::channelmanager::PaymentPreimage" => Some(".0 }"),
636 "ln::channelmanager::PaymentSecret" if !is_ref => Some(".0 }"),
638 // Override the default since Records contain an fmt with a lifetime:
639 "util::logger::Record" => Some(".as_ptr()"),
641 // List of structs we map (possibly during processing of other files):
642 "ln::features::InitFeatures" if is_ref && ptr_for_ref => Some(", is_owned: false }"),
643 "ln::features::InitFeatures" if is_ref => Some(", is_owned: false }))"),
644 "ln::features::InitFeatures" => Some(")), is_owned: true }"),
647 eprintln!(" Type {} unconvertable to C", full_path);
650 }.map(|s| s.to_owned())
653 fn empty_val_check_suffix_from_path(&self, full_path: &str) -> Option<&str> {
655 "ln::channelmanager::PaymentSecret" => Some(".data == [0; 32]"),
656 "bitcoin::secp256k1::key::PublicKey" => Some(".is_null()"),
657 "bitcoin::secp256k1::Signature" => Some(".is_null()"),
662 // ****************************
663 // *** Container Processing ***
664 // ****************************
666 /// Returns the module path in the generated mapping crate to the containers which we generate
667 /// when writing to CrateTypes::template_file.
668 fn generated_container_path() -> &'static str {
669 "crate::c_types::derived"
671 /// Returns the module path in the generated mapping crate to the container templates, which
672 /// are then concretized and put in the generated container path/template_file.
673 fn container_templ_path() -> &'static str {
677 /// Returns true if this is a "transparent" container, ie an Option or a container which does
678 /// not require a generated continer class.
679 fn is_transparent_container(&self, full_path: &str, _is_ref: bool) -> bool {
680 full_path == "Option"
682 /// Returns true if this is a known, supported, non-transparent container.
683 fn is_known_container(&self, full_path: &str, is_ref: bool) -> bool {
684 (full_path == "Result" && !is_ref) || (full_path == "Vec" && !is_ref) || full_path.ends_with("Tuple")
686 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)
687 // Returns prefix + Vec<(prefix, var-name-to-inline-convert)> + suffix
688 // expecting one element in the vec per generic type, each of which is inline-converted
689 -> Option<(&'b str, Vec<(String, String)>, &'b str)> {
691 "Result" if !is_ref => {
693 vec![(" { Ok(mut o) => crate::c_types::CResultTempl::ok(".to_string(), "o".to_string()),
694 ("), Err(mut e) => crate::c_types::CResultTempl::err(".to_string(), "e".to_string())],
697 "Vec" if !is_ref => {
698 Some(("Vec::new(); for item in ", vec![(format!(".drain(..) {{ local_{}.push(", var_name), "item".to_string())], "); }"))
701 Some(("Vec::new(); for item in ", vec![(format!(".iter() {{ local_{}.push(", var_name), "**item".to_string())], "); }"))
704 if let Some(syn::Type::Path(p)) = single_contained {
705 if self.c_type_has_inner_from_path(&self.resolve_path(&p.path, generics)) {
707 return Some(("if ", vec![
708 (".is_none() { std::ptr::null() } else { ".to_owned(), format!("({}.as_ref().unwrap())", var_access))
711 return Some(("if ", vec![
712 (".is_none() { std::ptr::null_mut() } else { ".to_owned(), format!("({}.unwrap())", var_access))
717 if let Some(t) = single_contained {
718 let mut v = Vec::new();
719 self.write_empty_rust_val(generics, &mut v, t);
720 let s = String::from_utf8(v).unwrap();
721 return Some(("if ", vec![
722 (format!(".is_none() {{ {} }} else {{ ", s), format!("({}.unwrap())", var_access))
724 } else { unreachable!(); }
730 /// only_contained_has_inner implies that there is only one contained element in the container
731 /// and it has an inner field (ie is an "opaque" type we've defined).
732 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)
733 // Returns prefix + Vec<(prefix, var-name-to-inline-convert)> + suffix
734 // expecting one element in the vec per generic type, each of which is inline-converted
735 -> Option<(&'b str, Vec<(String, String)>, &'b str)> {
737 "Result" if !is_ref => {
739 vec![(".result_ok { true => Ok(".to_string(), format!("(*unsafe {{ Box::from_raw({}.contents.result.take_ptr()) }})", var_name)),
740 ("), false => Err(".to_string(), format!("(*unsafe {{ Box::from_raw({}.contents.err.take_ptr()) }})", var_name))],
743 "Vec"|"Slice" if !is_ref => {
744 Some(("Vec::new(); for mut item in ", vec![(format!(".into_rust().drain(..) {{ local_{}.push(", var_name), "item".to_string())], "); }"))
746 "Slice" if is_ref => {
747 Some(("Vec::new(); for mut item in ", vec![(format!(".as_slice().iter() {{ local_{}.push(", var_name), "item".to_string())], "); }"))
750 if let Some(syn::Type::Path(p)) = single_contained {
751 if self.c_type_has_inner_from_path(&self.resolve_path(&p.path, generics)) {
753 return Some(("if ", vec![(".inner.is_null() { None } else { Some((*".to_string(), format!("{}", var_name))], ").clone()) }"))
755 return Some(("if ", vec![(".inner.is_null() { None } else { Some(".to_string(), format!("{}", var_name))], ") }"));
760 if let Some(t) = single_contained {
761 let mut v = Vec::new();
762 let needs_deref = self.write_empty_rust_val_check_suffix(generics, &mut v, t);
763 let s = String::from_utf8(v).unwrap();
765 return Some(("if ", vec![
766 (format!("{} {{ None }} else {{ Some(", s), format!("unsafe {{ &mut *{} }}", var_access))
769 return Some(("if ", vec![
770 (format!("{} {{ None }} else {{ Some(", s), format!("{}", var_access))
773 } else { unreachable!(); }
779 // *************************************************
780 // *** Type definition during main.rs processing ***
781 // *************************************************
783 fn process_use_intern<W: std::io::Write>(&mut self, w: &mut W, u: &syn::UseTree, partial_path: &str) {
785 syn::UseTree::Path(p) => {
786 let new_path = format!("{}::{}", partial_path, p.ident);
787 self.process_use_intern(w, &p.tree, &new_path);
789 syn::UseTree::Name(n) => {
790 let full_path = format!("{}::{}", partial_path, n.ident);
791 self.imports.insert(n.ident.clone(), full_path);
793 syn::UseTree::Group(g) => {
794 for i in g.items.iter() {
795 self.process_use_intern(w, i, partial_path);
798 syn::UseTree::Rename(r) => {
799 let full_path = format!("{}::{}", partial_path, r.ident);
800 self.imports.insert(r.rename.clone(), full_path);
802 syn::UseTree::Glob(_) => {
803 eprintln!("Ignoring * use for {} - this may result in resolution failures", partial_path);
807 pub fn process_use<W: std::io::Write>(&mut self, w: &mut W, u: &syn::ItemUse) {
808 if let syn::Visibility::Public(_) = u.vis {
809 // We actually only use these for #[cfg(fuzztarget)]
810 eprintln!("Ignoring pub(use) tree!");
814 syn::UseTree::Path(p) => {
815 let new_path = format!("{}", p.ident);
816 self.process_use_intern(w, &p.tree, &new_path);
818 syn::UseTree::Name(n) => {
819 let full_path = format!("{}", n.ident);
820 self.imports.insert(n.ident.clone(), full_path);
822 _ => unimplemented!(),
824 if u.leading_colon.is_some() { unimplemented!() }
827 pub fn mirrored_enum_declared(&mut self, ident: &syn::Ident) {
828 eprintln!("{} mirrored", ident);
829 self.declared.insert(ident.clone(), DeclType::MirroredEnum);
831 pub fn enum_ignored(&mut self, ident: &'c syn::Ident) {
832 self.declared.insert(ident.clone(), DeclType::EnumIgnored);
834 pub fn struct_imported(&mut self, ident: &'c syn::Ident, named: String) {
835 eprintln!("Imported {} as {}", ident, named);
836 self.declared.insert(ident.clone(), DeclType::StructImported);
838 pub fn struct_ignored(&mut self, ident: &syn::Ident) {
839 eprintln!("Not importing {}", ident);
840 self.declared.insert(ident.clone(), DeclType::StructIgnored);
842 pub fn trait_declared(&mut self, ident: &syn::Ident, t: &'c syn::ItemTrait) {
843 eprintln!("Trait {} created", ident);
844 self.declared.insert(ident.clone(), DeclType::Trait(t));
846 pub fn get_declared_type(&'a self, ident: &syn::Ident) -> Option<&'a DeclType<'c>> {
847 self.declared.get(ident)
849 /// Returns true if the object at the given path is mapped as X { inner: *mut origX, .. }.
850 fn c_type_has_inner_from_path(&self, full_path: &str) -> bool{
851 self.crate_types.opaques.get(full_path).is_some()
854 pub fn maybe_resolve_ident(&self, id: &syn::Ident) -> Option<String> {
855 if let Some(imp) = self.imports.get(id) {
857 } else if self.declared.get(id).is_some() {
858 Some(self.module_path.to_string() + "::" + &format!("{}", id))
862 pub fn maybe_resolve_non_ignored_ident(&self, id: &syn::Ident) -> Option<String> {
863 if let Some(imp) = self.imports.get(id) {
865 } else if let Some(decl_type) = self.declared.get(id) {
867 DeclType::StructIgnored => None,
868 _ => Some(self.module_path.to_string() + "::" + &format!("{}", id)),
873 pub fn maybe_resolve_path(&self, p_arg: &syn::Path, generics: Option<&GenericTypes>) -> Option<String> {
874 let p = if let Some(gen_types) = generics {
875 if let Some((_, synpath)) = gen_types.maybe_resolve_path(p_arg) {
880 if p.leading_colon.is_some() {
881 // At some point we may need this, but for now, its unused, so just fail.
883 } else if let Some(id) = p.get_ident() {
884 self.maybe_resolve_ident(id)
886 if p.segments.len() == 1 {
887 let seg = p.segments.iter().next().unwrap();
888 return self.maybe_resolve_ident(&seg.ident);
890 let mut seg_iter = p.segments.iter();
891 let first_seg = seg_iter.next().unwrap();
892 let remaining: String = seg_iter.map(|seg| {
893 if let syn::PathArguments::None = seg.arguments {
894 format!("{}", seg.ident)
896 format!("{}", seg.ident)
899 if let Some(imp) = self.imports.get(&first_seg.ident) {
901 Some(imp.clone() + "::" + &remaining)
908 pub fn resolve_path(&self, p: &syn::Path, generics: Option<&GenericTypes>) -> String {
909 self.maybe_resolve_path(p, generics).unwrap()
912 // ***********************************
913 // *** Original Rust Type Printing ***
914 // ***********************************
916 fn write_rust_path<W: std::io::Write>(&self, w: &mut W, path: &syn::Path) {
917 if let Some(resolved) = self.maybe_resolve_path(&path, None) {
918 if self.is_primitive(&resolved) {
919 write!(w, "{}", path.get_ident().unwrap()).unwrap();
921 if resolved.starts_with("ln::") || resolved.starts_with("chain::") || resolved.starts_with("util::") {
922 write!(w, "lightning::{}", resolved).unwrap();
924 write!(w, "{}", resolved).unwrap(); // XXX: Probably doens't work, get_ident().unwrap()
927 if let syn::PathArguments::AngleBracketed(args) = &path.segments.iter().last().unwrap().arguments {
928 self.write_rust_generic_arg(w, args.args.iter());
931 if path.leading_colon.is_some() {
932 write!(w, "::").unwrap();
934 for (idx, seg) in path.segments.iter().enumerate() {
935 if idx != 0 { write!(w, "::").unwrap(); }
936 write!(w, "{}", seg.ident).unwrap();
937 if let syn::PathArguments::AngleBracketed(args) = &seg.arguments {
938 self.write_rust_generic_arg(w, args.args.iter());
943 pub fn write_rust_generic_param<'b, W: std::io::Write>(&self, w: &mut W, generics: impl Iterator<Item=&'b syn::GenericParam>) {
944 let mut had_params = false;
945 for (idx, arg) in generics.enumerate() {
946 if idx != 0 { write!(w, ", ").unwrap(); } else { write!(w, "<").unwrap(); }
949 syn::GenericParam::Lifetime(lt) => write!(w, "'{}", lt.lifetime.ident).unwrap(),
950 syn::GenericParam::Type(t) => {
951 write!(w, "{}", t.ident).unwrap();
952 if t.colon_token.is_some() { write!(w, ":").unwrap(); }
953 for (idx, bound) in t.bounds.iter().enumerate() {
954 if idx != 0 { write!(w, " + ").unwrap(); }
956 syn::TypeParamBound::Trait(tb) => {
957 if tb.paren_token.is_some() || tb.lifetimes.is_some() { unimplemented!(); }
958 self.write_rust_path(w, &tb.path);
960 _ => unimplemented!(),
963 if t.eq_token.is_some() || t.default.is_some() { unimplemented!(); }
965 _ => unimplemented!(),
968 if had_params { write!(w, ">").unwrap(); }
971 pub fn write_rust_generic_arg<'b, W: std::io::Write>(&self, w: &mut W, generics: impl Iterator<Item=&'b syn::GenericArgument>) {
972 write!(w, "<").unwrap();
973 for (idx, arg) in generics.enumerate() {
974 if idx != 0 { write!(w, ", ").unwrap(); }
976 syn::GenericArgument::Type(t) => self.write_rust_type(w, t),
977 _ => unimplemented!(),
980 write!(w, ">").unwrap();
982 pub fn write_rust_type<W: std::io::Write>(&self, w: &mut W, t: &syn::Type) {
984 syn::Type::Path(p) => {
985 if p.qself.is_some() || p.path.leading_colon.is_some() {
988 self.write_rust_path(w, &p.path);
990 syn::Type::Reference(r) => {
991 write!(w, "&").unwrap();
992 if let Some(lft) = &r.lifetime {
993 write!(w, "'{} ", lft.ident).unwrap();
995 if r.mutability.is_some() {
996 write!(w, "mut ").unwrap();
998 self.write_rust_type(w, &*r.elem);
1000 syn::Type::Array(a) => {
1001 write!(w, "[").unwrap();
1002 self.write_rust_type(w, &a.elem);
1003 if let syn::Expr::Lit(l) = &a.len {
1004 if let syn::Lit::Int(i) = &l.lit {
1005 write!(w, "; {}]", i).unwrap();
1006 } else { unimplemented!(); }
1007 } else { unimplemented!(); }
1009 syn::Type::Slice(s) => {
1010 write!(w, "[").unwrap();
1011 self.write_rust_type(w, &s.elem);
1012 write!(w, "]").unwrap();
1014 syn::Type::Tuple(s) => {
1015 write!(w, "(").unwrap();
1016 for (idx, t) in s.elems.iter().enumerate() {
1017 if idx != 0 { write!(w, ", ").unwrap(); }
1018 self.write_rust_type(w, &t);
1020 write!(w, ")").unwrap();
1022 _ => unimplemented!(),
1026 /// Prints a constructor for something which is "uninitialized" (but obviously not actually
1027 /// unint'd memory).
1028 pub fn write_empty_rust_val<W: std::io::Write>(&self, generics: Option<&GenericTypes>, w: &mut W, t: &syn::Type) {
1030 syn::Type::Path(p) => {
1031 let resolved = self.resolve_path(&p.path, generics);
1032 if self.crate_types.opaques.get(&resolved).is_some() {
1033 write!(w, "crate::{} {{ inner: std::ptr::null_mut(), is_owned: true }}", resolved).unwrap();
1035 // Assume its a manually-mapped C type, where we can just define an null() fn
1036 write!(w, "{}::null()", self.c_type_from_path(&resolved, false, false).unwrap()).unwrap();
1039 syn::Type::Array(a) => {
1040 if let syn::Expr::Lit(l) = &a.len {
1041 if let syn::Lit::Int(i) = &l.lit {
1042 if i.base10_digits().parse::<usize>().unwrap() < 32 {
1043 // Blindly assume that if we're trying to create an empty value for an
1044 // array < 32 entries that all-0s may be a valid state.
1047 let arrty = format!("[u8; {}]", i.base10_digits());
1048 write!(w, "{}", self.to_c_conversion_inline_prefix_from_path(&arrty, false, false).unwrap()).unwrap();
1049 write!(w, "[0; {}]", i.base10_digits()).unwrap();
1050 write!(w, "{}", self.to_c_conversion_inline_suffix_from_path(&arrty, false, false).unwrap()).unwrap();
1051 } else { unimplemented!(); }
1052 } else { unimplemented!(); }
1054 _ => unimplemented!(),
1058 /// Prints a suffix to determine if a variable is empty (ie was set by write_empty_rust_val),
1059 /// returning whether we need to dereference the inner value before using it (ie it is a
1061 pub fn write_empty_rust_val_check_suffix<W: std::io::Write>(&self, generics: Option<&GenericTypes>, w: &mut W, t: &syn::Type) -> bool {
1063 syn::Type::Path(p) => {
1064 let resolved = self.resolve_path(&p.path, generics);
1065 if self.crate_types.opaques.get(&resolved).is_some() {
1066 write!(w, ".inner.is_null()").unwrap();
1069 if let Some(suffix) = self.empty_val_check_suffix_from_path(&resolved) {
1070 write!(w, "{}", suffix).unwrap();
1071 false // We may eventually need to allow empty_val_check_suffix_from_path to specify if we need a deref or not
1073 write!(w, " == std::ptr::null_mut()").unwrap();
1078 syn::Type::Array(a) => {
1079 if let syn::Expr::Lit(l) = &a.len {
1080 if let syn::Lit::Int(i) = &l.lit {
1081 write!(w, " == [0; {}]", i.base10_digits()).unwrap();
1083 } else { unimplemented!(); }
1084 } else { unimplemented!(); }
1086 syn::Type::Slice(_) => {
1087 // Option<[]> always implies that we want to treat len() == 0 differently from
1088 // None, so we always map an Option<[]> into a pointer.
1089 write!(w, " == std::ptr::null_mut()").unwrap();
1092 _ => unimplemented!(),
1096 /// Prints a suffix to determine if a variable is empty (ie was set by write_empty_rust_val).
1097 pub fn write_empty_rust_val_check<W: std::io::Write>(&self, generics: Option<&GenericTypes>, w: &mut W, t: &syn::Type, var_access: &str) {
1099 syn::Type::Path(_) => {
1100 write!(w, "{}", var_access).unwrap();
1101 self.write_empty_rust_val_check_suffix(generics, w, t);
1103 syn::Type::Array(a) => {
1104 if let syn::Expr::Lit(l) = &a.len {
1105 if let syn::Lit::Int(i) = &l.lit {
1106 let arrty = format!("[u8; {}]", i.base10_digits());
1107 // We don't (yet) support a new-var conversion here.
1108 assert!(self.from_c_conversion_new_var_from_path(&arrty, false).is_none());
1110 self.from_c_conversion_prefix_from_path(&arrty, false).unwrap(),
1112 self.from_c_conversion_suffix_from_path(&arrty, false).unwrap()).unwrap();
1113 self.write_empty_rust_val_check_suffix(generics, w, t);
1114 } else { unimplemented!(); }
1115 } else { unimplemented!(); }
1117 _ => unimplemented!(),
1121 // ********************************
1122 // *** Type conversion printing ***
1123 // ********************************
1125 /// Returns true we if can just skip passing this to C entirely
1126 pub fn skip_arg(&self, t: &syn::Type, generics: Option<&GenericTypes>) -> bool {
1128 syn::Type::Path(p) => {
1129 if p.qself.is_some() { unimplemented!(); }
1130 if let Some(full_path) = self.maybe_resolve_path(&p.path, generics) {
1131 self.skip_path(&full_path)
1134 syn::Type::Reference(r) => {
1135 self.skip_arg(&*r.elem, generics)
1140 pub fn no_arg_to_rust<W: std::io::Write>(&self, w: &mut W, t: &syn::Type, generics: Option<&GenericTypes>) {
1142 syn::Type::Path(p) => {
1143 if p.qself.is_some() { unimplemented!(); }
1144 if let Some(full_path) = self.maybe_resolve_path(&p.path, generics) {
1145 write!(w, "{}", self.no_arg_path_to_rust(&full_path)).unwrap();
1148 syn::Type::Reference(r) => {
1149 self.no_arg_to_rust(w, &*r.elem, generics);
1155 fn write_conversion_inline_intern<W: std::io::Write,
1156 LP: Fn(&str, bool, bool) -> Option<String>, DL: Fn(&mut W, &DeclType, &str, bool, bool), SC: Fn(bool) -> &'static str>
1157 (&self, w: &mut W, t: &syn::Type, generics: Option<&GenericTypes>, is_ref: bool, is_mut: bool, ptr_for_ref: bool,
1158 tupleconv: &str, prefix: bool, sliceconv: SC, path_lookup: LP, decl_lookup: DL) {
1160 syn::Type::Reference(r) => {
1161 self.write_conversion_inline_intern(w, &*r.elem, generics, true, r.mutability.is_some(),
1162 ptr_for_ref, tupleconv, prefix, sliceconv, path_lookup, decl_lookup);
1164 syn::Type::Path(p) => {
1165 if p.qself.is_some() || p.path.leading_colon.is_some() {
1169 let resolved_path = self.resolve_path(&p.path, generics);
1170 if let Some(c_type) = path_lookup(&resolved_path, is_ref, ptr_for_ref) {
1171 write!(w, "{}", c_type).unwrap();
1172 } else if self.crate_types.opaques.get(&resolved_path).is_some() {
1173 decl_lookup(w, &DeclType::StructImported, &resolved_path, is_ref, is_mut);
1174 } else if self.crate_types.mirrored_enums.get(&resolved_path).is_some() {
1175 decl_lookup(w, &DeclType::MirroredEnum, &resolved_path, is_ref, is_mut);
1176 } else if let Some(ident) = single_ident_generic_path_to_ident(&p.path) {
1177 if let Some(t) = self.crate_types.traits.get(&resolved_path) {
1178 decl_lookup(w, &DeclType::Trait(t), &resolved_path, is_ref, is_mut);
1180 } else if let Some(_) = self.imports.get(ident) {
1181 // crate_types lookup has to have succeeded:
1182 panic!("Failed to print inline conversion for {}", ident);
1183 } else if let Some(decl_type) = self.declared.get(ident) {
1184 decl_lookup(w, decl_type, &self.maybe_resolve_ident(ident).unwrap(), is_ref, is_mut);
1185 } else { unimplemented!(); }
1188 syn::Type::Array(a) => {
1189 // We assume all arrays contain only [int_literal; X]s.
1190 // This may result in some outputs not compiling.
1191 if let syn::Expr::Lit(l) = &a.len {
1192 if let syn::Lit::Int(i) = &l.lit {
1193 write!(w, "{}", path_lookup(&format!("[u8; {}]", i.base10_digits()), is_ref, ptr_for_ref).unwrap()).unwrap();
1194 } else { unimplemented!(); }
1195 } else { unimplemented!(); }
1197 syn::Type::Slice(s) => {
1198 // We assume all slices contain only literals or references.
1199 // This may result in some outputs not compiling.
1200 if let syn::Type::Path(p) = &*s.elem {
1201 let resolved = self.resolve_path(&p.path, generics);
1202 assert!(self.is_primitive(&resolved));
1203 write!(w, "{}", path_lookup("[u8]", is_ref, ptr_for_ref).unwrap()).unwrap();
1204 } else if let syn::Type::Reference(r) = &*s.elem {
1205 if let syn::Type::Path(p) = &*r.elem {
1206 write!(w, "{}", sliceconv(self.c_type_has_inner_from_path(&self.resolve_path(&p.path, generics)))).unwrap();
1207 } else { unimplemented!(); }
1208 } else { unimplemented!(); }
1210 syn::Type::Tuple(t) => {
1211 if t.elems.is_empty() {
1212 // cbindgen has poor support for (), see, eg https://github.com/eqrion/cbindgen/issues/527
1213 // so work around it by just pretending its a 0u8
1214 write!(w, "{}", tupleconv).unwrap();
1216 if prefix { write!(w, "local_").unwrap(); }
1219 _ => unimplemented!(),
1223 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) {
1224 self.write_conversion_inline_intern(w, t, generics, is_ref, false, ptr_for_ref, "0u8 /*", true, |_| "local_",
1225 |a, b, c| self.to_c_conversion_inline_prefix_from_path(a, b, c),
1226 |w, decl_type, decl_path, is_ref, _is_mut| {
1228 DeclType::MirroredEnum if is_ref && ptr_for_ref => write!(w, "crate::{}::from_native(&", decl_path).unwrap(),
1229 DeclType::MirroredEnum if is_ref => write!(w, "&crate::{}::from_native(&", decl_path).unwrap(),
1230 DeclType::MirroredEnum => write!(w, "crate::{}::native_into(", decl_path).unwrap(),
1231 DeclType::EnumIgnored|DeclType::StructImported if is_ref && ptr_for_ref && from_ptr =>
1232 write!(w, "crate::{} {{ inner: unsafe {{ (", decl_path).unwrap(),
1233 DeclType::EnumIgnored|DeclType::StructImported if is_ref && ptr_for_ref =>
1234 write!(w, "crate::{} {{ inner: unsafe {{ ( (&(", decl_path).unwrap(),
1235 DeclType::EnumIgnored|DeclType::StructImported if is_ref =>
1236 write!(w, "&crate::{} {{ inner: unsafe {{ (", decl_path).unwrap(),
1237 DeclType::EnumIgnored|DeclType::StructImported if !is_ref && from_ptr =>
1238 write!(w, "crate::{} {{ inner: ", decl_path).unwrap(),
1239 DeclType::EnumIgnored|DeclType::StructImported if !is_ref =>
1240 write!(w, "crate::{} {{ inner: Box::into_raw(Box::new(", decl_path).unwrap(),
1241 DeclType::Trait(_) if is_ref => write!(w, "&").unwrap(),
1242 _ => panic!("{:?}", decl_path),
1246 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) {
1247 self.write_to_c_conversion_inline_prefix_inner(w, t, generics, false, ptr_for_ref, false);
1249 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) {
1250 self.write_conversion_inline_intern(w, t, generics, is_ref, false, ptr_for_ref, "*/", false, |_| ".into()",
1251 |a, b, c| self.to_c_conversion_inline_suffix_from_path(a, b, c),
1252 |w, decl_type, _full_path, is_ref, _is_mut| match decl_type {
1253 DeclType::MirroredEnum => write!(w, ")").unwrap(),
1254 DeclType::EnumIgnored|DeclType::StructImported if is_ref && ptr_for_ref && from_ptr =>
1255 write!(w, " as *const _) as *mut _ }}, is_owned: false }}").unwrap(),
1256 DeclType::EnumIgnored|DeclType::StructImported if is_ref && ptr_for_ref =>
1257 write!(w, ") as *const _) as *mut _) }}, is_owned: false }}").unwrap(),
1258 DeclType::EnumIgnored|DeclType::StructImported if is_ref =>
1259 write!(w, " as *const _) as *mut _ }}, is_owned: false }}").unwrap(),
1260 DeclType::EnumIgnored|DeclType::StructImported if !is_ref && from_ptr =>
1261 write!(w, ", is_owned: true }}").unwrap(),
1262 DeclType::EnumIgnored|DeclType::StructImported if !is_ref => write!(w, ")), is_owned: true }}").unwrap(),
1263 DeclType::Trait(_) if is_ref => {},
1264 _ => unimplemented!(),
1267 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) {
1268 self.write_to_c_conversion_inline_suffix_inner(w, t, generics, false, ptr_for_ref, false);
1271 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) {
1272 self.write_conversion_inline_intern(w, t, generics, is_ref, false, false, "() /*", true, |_| "&local_",
1273 |a, b, _c| self.from_c_conversion_prefix_from_path(a, b),
1274 |w, decl_type, _full_path, is_ref, is_mut| match decl_type {
1275 DeclType::StructImported if is_ref && ptr_for_ref => write!(w, "unsafe {{ &*(*").unwrap(),
1276 DeclType::StructImported if is_mut && is_ref => write!(w, "unsafe {{ &mut *").unwrap(),
1277 DeclType::StructImported if is_ref => write!(w, "unsafe {{ &*").unwrap(),
1278 DeclType::StructImported if !is_ref => write!(w, "*unsafe {{ Box::from_raw(").unwrap(),
1279 DeclType::MirroredEnum if is_ref => write!(w, "&").unwrap(),
1280 DeclType::MirroredEnum => {},
1281 DeclType::Trait(_) => {},
1282 _ => unimplemented!(),
1285 pub fn write_from_c_conversion_prefix<W: std::io::Write>(&self, w: &mut W, t: &syn::Type, generics: Option<&GenericTypes>) {
1286 self.write_from_c_conversion_prefix_inner(w, t, generics, false, false);
1288 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) {
1289 self.write_conversion_inline_intern(w, t, generics, is_ref, false, false, "*/", false,
1290 |has_inner| match has_inner {
1291 false => ".iter().collect::<Vec<_>>()[..]",
1294 |a, b, _c| self.from_c_conversion_suffix_from_path(a, b),
1295 |w, decl_type, _full_path, is_ref, _is_mut| match decl_type {
1296 DeclType::StructImported if is_ref && ptr_for_ref => write!(w, ").inner }}").unwrap(),
1297 DeclType::StructImported if is_ref => write!(w, ".inner }}").unwrap(),
1298 DeclType::StructImported if !is_ref => write!(w, ".take_ptr()) }}").unwrap(),
1299 DeclType::MirroredEnum if is_ref => write!(w, ".to_native()").unwrap(),
1300 DeclType::MirroredEnum => write!(w, ".into_native()").unwrap(),
1301 DeclType::Trait(_) => {},
1302 _ => unimplemented!(),
1305 pub fn write_from_c_conversion_suffix<W: std::io::Write>(&self, w: &mut W, t: &syn::Type, generics: Option<&GenericTypes>) {
1306 self.write_from_c_conversion_suffix_inner(w, t, generics, false, false);
1308 // Note that compared to the above conversion functions, the following two are generally
1309 // significantly undertested:
1310 pub fn write_from_c_conversion_to_ref_prefix<W: std::io::Write>(&self, w: &mut W, t: &syn::Type, generics: Option<&GenericTypes>) {
1311 self.write_conversion_inline_intern(w, t, generics, false, false, false, "() /*", true, |_| "&local_",
1313 if let Some(conv) = self.from_c_conversion_prefix_from_path(a, b) {
1314 Some(format!("&{}", conv))
1317 |w, decl_type, _full_path, is_ref, _is_mut| match decl_type {
1318 DeclType::StructImported if !is_ref => write!(w, "unsafe {{ &*").unwrap(),
1319 _ => unimplemented!(),
1322 pub fn write_from_c_conversion_to_ref_suffix<W: std::io::Write>(&self, w: &mut W, t: &syn::Type, generics: Option<&GenericTypes>) {
1323 self.write_conversion_inline_intern(w, t, generics, false, false, false, "*/", false,
1324 |has_inner| match has_inner {
1325 false => ".iter().collect::<Vec<_>>()[..]",
1328 |a, b, _c| self.from_c_conversion_suffix_from_path(a, b),
1329 |w, decl_type, _full_path, is_ref, _is_mut| match decl_type {
1330 DeclType::StructImported if !is_ref => write!(w, ".inner }}").unwrap(),
1331 _ => unimplemented!(),
1335 fn write_conversion_new_var_intern<'b, W: std::io::Write,
1336 LP: Fn(&str, bool) -> Option<(&str, &str)>,
1337 LC: Fn(&str, bool, Option<&syn::Type>, &syn::Ident, &str) -> Option<(&'b str, Vec<(String, String)>, &'b str)>,
1338 VP: Fn(&mut W, &syn::Type, Option<&GenericTypes>, bool, bool, bool),
1339 VS: Fn(&mut W, &syn::Type, Option<&GenericTypes>, bool, bool, bool)>
1340 (&self, w: &mut W, ident: &syn::Ident, var: &str, t: &syn::Type, generics: Option<&GenericTypes>,
1341 mut is_ref: bool, mut ptr_for_ref: bool, to_c: bool,
1342 path_lookup: &LP, container_lookup: &LC, var_prefix: &VP, var_suffix: &VS) -> bool {
1344 macro_rules! convert_container {
1345 ($container_type: expr, $args_len: expr, $args_iter: expr) => { {
1346 // For slices (and Options), we refuse to directly map them as is_ref when they
1347 // aren't opaque types containing an inner pointer. This is due to the fact that,
1348 // in both cases, the actual higher-level type is non-is_ref.
1349 let ty_has_inner = if self.is_transparent_container(&$container_type, is_ref) || $container_type == "Slice" {
1350 let ty = $args_iter().next().unwrap();
1351 if $container_type == "Slice" && to_c {
1352 // "To C ptr_for_ref" means "return the regular object with is_owned
1353 // set to false", which is totally what we want in a slice if we're about to
1354 // set ty_has_inner.
1357 if let syn::Type::Reference(t) = ty {
1358 if let syn::Type::Path(p) = &*t.elem {
1359 self.c_type_has_inner_from_path(&self.resolve_path(&p.path, generics))
1361 } else if let syn::Type::Path(p) = ty {
1362 self.c_type_has_inner_from_path(&self.resolve_path(&p.path, generics))
1366 // Options get a bunch of special handling, since in general we map Option<>al
1367 // types into the same C type as non-Option-wrapped types. This ends up being
1368 // pretty manual here and most of the below special-cases are for Options.
1369 let mut needs_ref_map = false;
1370 let mut only_contained_type = None;
1371 let mut only_contained_has_inner = false;
1372 let mut contains_slice = false;
1373 if $args_len == 1 && self.is_transparent_container(&$container_type, is_ref) {
1374 only_contained_has_inner = ty_has_inner;
1375 let arg = $args_iter().next().unwrap();
1376 if let syn::Type::Reference(t) = arg {
1377 only_contained_type = Some(&*t.elem);
1378 if let syn::Type::Path(_) = &*t.elem {
1380 } else if let syn::Type::Slice(_) = &*t.elem {
1381 contains_slice = true;
1382 } else { return false; }
1383 needs_ref_map = true;
1384 } else if let syn::Type::Path(_) = arg {
1385 only_contained_type = Some(&arg);
1386 } else { unimplemented!(); }
1389 if let Some((prefix, conversions, suffix)) = container_lookup(&$container_type, is_ref && ty_has_inner, only_contained_type, ident, var) {
1390 assert_eq!(conversions.len(), $args_len);
1391 write!(w, "let mut local_{}{} = ", ident, if !to_c && needs_ref_map {"_base"} else { "" }).unwrap();
1392 if only_contained_has_inner && to_c {
1393 var_prefix(w, $args_iter().next().unwrap(), generics, is_ref, ptr_for_ref, true);
1395 write!(w, "{}{}", prefix, var).unwrap();
1397 for ((pfx, var_name), (idx, ty)) in conversions.iter().zip($args_iter().enumerate()) {
1398 let mut var = std::io::Cursor::new(Vec::new());
1399 write!(&mut var, "{}", var_name).unwrap();
1400 let var_access = String::from_utf8(var.into_inner()).unwrap();
1402 let conv_ty = if needs_ref_map { only_contained_type.as_ref().unwrap() } else { ty };
1404 write!(w, "{} {{ ", pfx).unwrap();
1405 let new_var_name = format!("{}_{}", ident, idx);
1406 let new_var = self.write_conversion_new_var_intern(w, &syn::Ident::new(&new_var_name, Span::call_site()),
1407 &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);
1408 if new_var { write!(w, " ").unwrap(); }
1409 if (!only_contained_has_inner || !to_c) && !contains_slice {
1410 var_prefix(w, conv_ty, generics, is_ref && ty_has_inner, ptr_for_ref, false);
1413 if !is_ref && !needs_ref_map && to_c && only_contained_has_inner {
1414 write!(w, "Box::into_raw(Box::new(").unwrap();
1416 write!(w, "{}{}", if contains_slice { "local_" } else { "" }, if new_var { new_var_name } else { var_access }).unwrap();
1417 if (!only_contained_has_inner || !to_c) && !contains_slice {
1418 var_suffix(w, conv_ty, generics, is_ref && ty_has_inner, ptr_for_ref, false);
1420 if !is_ref && !needs_ref_map && to_c && only_contained_has_inner {
1421 write!(w, "))").unwrap();
1423 write!(w, " }}").unwrap();
1425 write!(w, "{}", suffix).unwrap();
1426 if only_contained_has_inner && to_c {
1427 var_suffix(w, $args_iter().next().unwrap(), generics, is_ref, ptr_for_ref, true);
1429 write!(w, ";").unwrap();
1430 if !to_c && needs_ref_map {
1431 write!(w, " let mut local_{} = local_{}_base.as_ref()", ident, ident).unwrap();
1433 write!(w, ".map(|a| &a[..])").unwrap();
1435 write!(w, ";").unwrap();
1443 syn::Type::Reference(r) => {
1444 if let syn::Type::Slice(_) = &*r.elem {
1445 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)
1447 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)
1450 syn::Type::Path(p) => {
1451 if p.qself.is_some() || p.path.leading_colon.is_some() {
1454 let resolved_path = self.resolve_path(&p.path, generics);
1455 if self.is_known_container(&resolved_path, is_ref) || self.is_transparent_container(&resolved_path, is_ref) {
1456 if let syn::PathArguments::AngleBracketed(args) = &p.path.segments.iter().next().unwrap().arguments {
1457 convert_container!(resolved_path, args.args.len(), || args.args.iter().map(|arg| {
1458 if let syn::GenericArgument::Type(ty) = arg {
1460 } else { unimplemented!(); }
1462 } else { unimplemented!(); }
1464 if self.is_primitive(&resolved_path) {
1466 } else if let Some(ty_ident) = single_ident_generic_path_to_ident(&p.path) {
1467 if let Some((prefix, suffix)) = path_lookup(&resolved_path, is_ref) {
1468 write!(w, "let mut local_{} = {}{}{};", ident, prefix, var, suffix).unwrap();
1470 } else if self.declared.get(ty_ident).is_some() {
1475 syn::Type::Array(_) => {
1476 // We assume all arrays contain only primitive types.
1477 // This may result in some outputs not compiling.
1480 syn::Type::Slice(s) => {
1481 if let syn::Type::Path(p) = &*s.elem {
1482 let resolved = self.resolve_path(&p.path, generics);
1483 assert!(self.is_primitive(&resolved));
1484 let slice_path = format!("[{}]", resolved);
1485 if let Some((prefix, suffix)) = path_lookup(&slice_path, true) {
1486 write!(w, "let mut local_{} = {}{}{};", ident, prefix, var, suffix).unwrap();
1489 } else if let syn::Type::Reference(ty) = &*s.elem {
1490 let tyref = [&*ty.elem];
1492 convert_container!("Slice", 1, || tyref.iter());
1493 unimplemented!("convert_container should return true as container_lookup should succeed for slices");
1494 } else { unimplemented!() }
1496 syn::Type::Tuple(t) => {
1497 if !t.elems.is_empty() {
1498 // We don't (yet) support tuple elements which cannot be converted inline
1499 write!(w, "let (").unwrap();
1500 for idx in 0..t.elems.len() {
1501 if idx != 0 { write!(w, ", ").unwrap(); }
1502 write!(w, "{} orig_{}_{}", if is_ref { "ref" } else { "mut" }, ident, idx).unwrap();
1504 write!(w, ") = {}{}; ", var, if !to_c { ".to_rust()" } else { "" }).unwrap();
1505 // Like other template types, tuples are always mapped as their non-ref
1506 // versions for types which have different ref mappings. Thus, we convert to
1507 // non-ref versions and handle opaque types with inner pointers manually.
1508 for (idx, elem) in t.elems.iter().enumerate() {
1509 if let syn::Type::Path(p) = elem {
1510 let v_name = format!("orig_{}_{}", ident, idx);
1511 let tuple_elem_ident = syn::Ident::new(&v_name, Span::call_site());
1512 if self.write_conversion_new_var_intern(w, &tuple_elem_ident, &v_name, elem, generics,
1513 false, ptr_for_ref, to_c,
1514 path_lookup, container_lookup, var_prefix, var_suffix) {
1515 write!(w, " ").unwrap();
1516 // Opaque types with inner pointers shouldn't ever create new stack
1517 // variables, so we don't handle it and just assert that it doesn't
1519 assert!(!self.c_type_has_inner_from_path(&self.resolve_path(&p.path, generics)));
1523 write!(w, "let mut local_{} = (", ident).unwrap();
1524 for (idx, elem) in t.elems.iter().enumerate() {
1525 let ty_has_inner = {
1527 // "To C ptr_for_ref" means "return the regular object with
1528 // is_owned set to false", which is totally what we want
1529 // if we're about to set ty_has_inner.
1532 if let syn::Type::Reference(t) = elem {
1533 if let syn::Type::Path(p) = &*t.elem {
1534 self.c_type_has_inner_from_path(&self.resolve_path(&p.path, generics))
1536 } else if let syn::Type::Path(p) = elem {
1537 self.c_type_has_inner_from_path(&self.resolve_path(&p.path, generics))
1540 if idx != 0 { write!(w, ", ").unwrap(); }
1541 var_prefix(w, elem, generics, is_ref && ty_has_inner, ptr_for_ref, false);
1542 if is_ref && ty_has_inner {
1543 // For ty_has_inner, the regular var_prefix mapping will take a
1544 // reference, so deref once here to make sure we keep the original ref.
1545 write!(w, "*").unwrap();
1547 write!(w, "orig_{}_{}", ident, idx).unwrap();
1548 if is_ref && !ty_has_inner {
1549 // If we don't have an inner variable's reference to maintain, just
1550 // hope the type is Clonable and use that.
1551 write!(w, ".clone()").unwrap();
1553 var_suffix(w, elem, generics, is_ref && ty_has_inner, ptr_for_ref, false);
1555 write!(w, "){};", if to_c { ".into()" } else { "" }).unwrap();
1559 _ => unimplemented!(),
1563 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 {
1564 self.write_conversion_new_var_intern(w, ident, var_access, t, generics, false, ptr_for_ref, true,
1565 &|a, b| self.to_c_conversion_new_var_from_path(a, b),
1566 &|a, b, c, d, e| self.to_c_conversion_container_new_var(generics, a, b, c, d, e),
1567 // We force ptr_for_ref here since we can't generate a ref on one line and use it later
1568 &|a, b, c, d, e, f| self.write_to_c_conversion_inline_prefix_inner(a, b, c, d, e, f),
1569 &|a, b, c, d, e, f| self.write_to_c_conversion_inline_suffix_inner(a, b, c, d, e, f))
1571 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 {
1572 self.write_to_c_conversion_new_var_inner(w, ident, &format!("{}", ident), t, generics, ptr_for_ref)
1574 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 {
1575 self.write_conversion_new_var_intern(w, ident, &format!("{}", ident), t, generics, false, false, false,
1576 &|a, b| self.from_c_conversion_new_var_from_path(a, b),
1577 &|a, b, c, d, e| self.from_c_conversion_container_new_var(generics, a, b, c, d, e),
1578 // We force ptr_for_ref here since we can't generate a ref on one line and use it later
1579 &|a, b, c, d, e, _f| self.write_from_c_conversion_prefix_inner(a, b, c, d, e),
1580 &|a, b, c, d, e, _f| self.write_from_c_conversion_suffix_inner(a, b, c, d, e))
1583 // ******************************************************
1584 // *** C Container Type Equivalent and alias Printing ***
1585 // ******************************************************
1587 fn write_template_constructor<W: std::io::Write>(&mut self, w: &mut W, container_type: &str, mangled_container: &str, args: &Vec<&syn::Type>, generics: Option<&GenericTypes>, is_ref: bool) {
1588 if container_type == "Result" {
1589 assert_eq!(args.len(), 2);
1590 macro_rules! write_fn {
1591 ($call: expr) => { {
1592 writeln!(w, "#[no_mangle]\npub extern \"C\" fn {}_{}() -> {} {{", mangled_container, $call, mangled_container).unwrap();
1593 writeln!(w, "\t{}::CResultTempl::{}(0)\n}}\n", Self::container_templ_path(), $call).unwrap();
1596 macro_rules! write_alias {
1597 ($call: expr, $item: expr) => { {
1598 write!(w, "#[no_mangle]\npub static {}_{}: extern \"C\" fn (", mangled_container, $call).unwrap();
1599 if let syn::Type::Path(syn::TypePath { path, .. }) = $item {
1600 let resolved = self.resolve_path(path, generics);
1601 if self.is_known_container(&resolved, is_ref) || self.is_transparent_container(&resolved, is_ref) {
1602 self.write_c_mangled_container_path_intern(w, Self::path_to_generic_args(path), generics,
1603 &format!("{}", single_ident_generic_path_to_ident(path).unwrap()), is_ref, false, false, false);
1605 self.write_template_generics(w, &mut [$item].iter().map(|t| *t), is_ref, true);
1607 } else if let syn::Type::Tuple(syn::TypeTuple { elems, .. }) = $item {
1608 self.write_c_mangled_container_path_intern(w, elems.iter().collect(), generics,
1609 &format!("{}Tuple", elems.len()), is_ref, false, false, false);
1610 } else { unimplemented!(); }
1611 write!(w, ") -> {} =\n\t{}::CResultTempl::<", mangled_container, Self::container_templ_path()).unwrap();
1612 self.write_template_generics(w, &mut args.iter().map(|t| *t), is_ref, true);
1613 writeln!(w, ">::{};\n", $call).unwrap();
1617 syn::Type::Tuple(t) if t.elems.is_empty() => write_fn!("ok"),
1618 _ => write_alias!("ok", args[0]),
1621 syn::Type::Tuple(t) if t.elems.is_empty() => write_fn!("err"),
1622 _ => write_alias!("err", args[1]),
1624 } else if container_type.ends_with("Tuple") {
1625 write!(w, "#[no_mangle]\npub extern \"C\" fn {}_new(", mangled_container).unwrap();
1626 for (idx, gen) in args.iter().enumerate() {
1627 write!(w, "{}{}: ", if idx != 0 { ", " } else { "" }, ('a' as u8 + idx as u8) as char).unwrap();
1628 self.write_c_type_intern(w, gen, None, false, false, false);
1630 writeln!(w, ") -> {} {{", mangled_container).unwrap();
1631 writeln!(w, "\t{} {{", mangled_container).unwrap();
1632 for idx in 0..args.len() {
1633 writeln!(w, "\t\t{}: Box::into_raw(Box::new({})),", ('a' as u8 + idx as u8) as char, ('a' as u8 + idx as u8) as char).unwrap();
1635 writeln!(w, "\t}}\n}}\n").unwrap();
1637 writeln!(w, "").unwrap();
1641 fn write_template_generics<'b, W: std::io::Write>(&self, w: &mut W, args: &mut dyn Iterator<Item=&'b syn::Type>, is_ref: bool, in_crate: bool) {
1642 for (idx, t) in args.enumerate() {
1644 write!(w, ", ").unwrap();
1646 if let syn::Type::Tuple(tup) = t {
1647 if tup.elems.is_empty() {
1648 write!(w, "u8").unwrap();
1650 write!(w, "{}::C{}TupleTempl<", Self::container_templ_path(), tup.elems.len()).unwrap();
1651 self.write_template_generics(w, &mut tup.elems.iter(), is_ref, in_crate);
1652 write!(w, ">").unwrap();
1654 } else if let syn::Type::Path(p_arg) = t {
1655 let resolved_generic = self.resolve_path(&p_arg.path, None);
1656 if self.is_primitive(&resolved_generic) {
1657 write!(w, "{}", resolved_generic).unwrap();
1658 } else if let Some(c_type) = self.c_type_from_path(&resolved_generic, is_ref, false) {
1659 if self.is_known_container(&resolved_generic, is_ref) {
1660 write!(w, "{}::C{}Templ<", Self::container_templ_path(), single_ident_generic_path_to_ident(&p_arg.path).unwrap()).unwrap();
1661 assert_eq!(p_arg.path.segments.len(), 1);
1662 if let syn::PathArguments::AngleBracketed(args) = &p_arg.path.segments.iter().next().unwrap().arguments {
1663 self.write_template_generics(w, &mut args.args.iter().map(|gen|
1664 if let syn::GenericArgument::Type(t) = gen { t } else { unimplemented!() }),
1666 } else { unimplemented!(); }
1667 write!(w, ">").unwrap();
1668 } else if resolved_generic == "Option" {
1669 if let syn::PathArguments::AngleBracketed(args) = &p_arg.path.segments.iter().next().unwrap().arguments {
1670 self.write_template_generics(w, &mut args.args.iter().map(|gen|
1671 if let syn::GenericArgument::Type(t) = gen { t } else { unimplemented!() }),
1673 } else { unimplemented!(); }
1674 } else if in_crate {
1675 write!(w, "{}", c_type).unwrap();
1677 self.write_rust_type(w, &t);
1680 // If we just write out resolved_generic, it may mostly work, however for
1681 // original types which are generic, we need the template args. We could
1682 // figure them out and write them out, too, but its much easier to just
1683 // reference the native{} type alias which exists at least for opaque types.
1685 write!(w, "crate::{}", resolved_generic).unwrap();
1687 let path_name: Vec<&str> = resolved_generic.rsplitn(2, "::").collect();
1688 if path_name.len() > 1 {
1689 write!(w, "crate::{}::native{}", path_name[1], path_name[0]).unwrap();
1691 write!(w, "crate::native{}", path_name[0]).unwrap();
1695 } else if let syn::Type::Reference(r_arg) = t {
1696 if let syn::Type::Path(p_arg) = &*r_arg.elem {
1697 let resolved = self.resolve_path(&p_arg.path, None);
1698 if single_ident_generic_path_to_ident(&p_arg.path).is_some() {
1699 if self.crate_types.opaques.get(&resolved).is_some() {
1700 write!(w, "crate::{}", resolved).unwrap();
1701 } else { unimplemented!(); }
1702 } else { unimplemented!(); }
1703 } else { unimplemented!(); }
1704 } else if let syn::Type::Array(a_arg) = t {
1705 if let syn::Type::Path(p_arg) = &*a_arg.elem {
1706 let resolved = self.resolve_path(&p_arg.path, None);
1707 assert!(self.is_primitive(&resolved));
1708 if let syn::Expr::Lit(syn::ExprLit { lit: syn::Lit::Int(len), .. }) = &a_arg.len {
1710 self.c_type_from_path(&format!("[{}; {}]", resolved, len.base10_digits()), is_ref, false).unwrap()).unwrap();
1716 fn check_create_container(&mut self, mangled_container: String, container_type: &str, args: Vec<&syn::Type>, generics: Option<&GenericTypes>, is_ref: bool) {
1717 if !self.crate_types.templates_defined.get(&mangled_container).is_some() {
1718 self.crate_types.templates_defined.insert(mangled_container.clone(), true);
1719 let mut created_container: Vec<u8> = Vec::new();
1721 write!(&mut created_container, "#[no_mangle]\npub type {} = ", mangled_container).unwrap();
1722 write!(&mut created_container, "{}::C{}Templ<", Self::container_templ_path(), container_type).unwrap();
1723 self.write_template_generics(&mut created_container, &mut args.iter().map(|t| *t), is_ref, true);
1724 writeln!(&mut created_container, ">;").unwrap();
1726 write!(&mut created_container, "#[no_mangle]\npub static {}_free: extern \"C\" fn({}) = ", mangled_container, mangled_container).unwrap();
1727 write!(&mut created_container, "{}::C{}Templ_free::<", Self::container_templ_path(), container_type).unwrap();
1728 self.write_template_generics(&mut created_container, &mut args.iter().map(|t| *t), is_ref, true);
1729 writeln!(&mut created_container, ">;").unwrap();
1731 self.write_template_constructor(&mut created_container, container_type, &mangled_container, &args, generics, is_ref);
1733 self.crate_types.template_file.write(&created_container).unwrap();
1736 fn path_to_generic_args(path: &syn::Path) -> Vec<&syn::Type> {
1737 if let syn::PathArguments::AngleBracketed(args) = &path.segments.iter().next().unwrap().arguments {
1738 args.args.iter().map(|gen| if let syn::GenericArgument::Type(t) = gen { t } else { unimplemented!() }).collect()
1739 } else { unimplemented!(); }
1741 fn write_c_mangled_container_path_intern<W: std::io::Write>
1742 (&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 {
1743 let mut mangled_type: Vec<u8> = Vec::new();
1744 if !self.is_transparent_container(ident, is_ref) {
1745 write!(w, "C{}_", ident).unwrap();
1746 write!(mangled_type, "C{}_", ident).unwrap();
1747 } else { assert_eq!(args.len(), 1); }
1748 for arg in args.iter() {
1749 macro_rules! write_path {
1750 ($p_arg: expr, $extra_write: expr) => {
1751 let subtype = self.resolve_path(&$p_arg.path, generics);
1752 if self.is_transparent_container(ident, is_ref) {
1753 // We dont (yet) support primitives or containers inside transparent
1754 // containers, so check for that first:
1755 if self.is_primitive(&subtype) { return false; }
1756 if self.is_known_container(&subtype, is_ref) { return false; }
1758 if self.c_type_has_inner_from_path(&subtype) {
1759 if !self.write_c_path_intern(w, &$p_arg.path, generics, is_ref, is_mut, ptr_for_ref) { return false; }
1761 if !self.write_c_path_intern(w, &$p_arg.path, generics, true, is_mut, true) { return false; }
1764 if $p_arg.path.segments.len() == 1 {
1765 write!(w, "{}", $p_arg.path.segments.iter().next().unwrap().ident).unwrap();
1770 } else if self.is_known_container(&subtype, is_ref) || self.is_transparent_container(&subtype, is_ref) {
1771 if !self.write_c_mangled_container_path_intern(w, Self::path_to_generic_args(&$p_arg.path), generics,
1772 &subtype, is_ref, is_mut, ptr_for_ref, true) {
1775 self.write_c_mangled_container_path_intern(&mut mangled_type, Self::path_to_generic_args(&$p_arg.path),
1776 generics, &subtype, is_ref, is_mut, ptr_for_ref, true);
1777 if let Some(w2) = $extra_write as Option<&mut Vec<u8>> {
1778 self.write_c_mangled_container_path_intern(w2, Self::path_to_generic_args(&$p_arg.path),
1779 generics, &subtype, is_ref, is_mut, ptr_for_ref, true);
1781 } else if let Some(id) = single_ident_generic_path_to_ident(&$p_arg.path) {
1782 write!(w, "{}", id).unwrap();
1783 write!(mangled_type, "{}", id).unwrap();
1784 if let Some(w2) = $extra_write as Option<&mut Vec<u8>> {
1785 write!(w2, "{}", id).unwrap();
1787 } else { return false; }
1790 if let syn::Type::Tuple(tuple) = arg {
1791 if tuple.elems.len() == 0 {
1792 write!(w, "None").unwrap();
1793 write!(mangled_type, "None").unwrap();
1795 let mut mangled_tuple_type: Vec<u8> = Vec::new();
1797 // Figure out what the mangled type should look like. To disambiguate
1798 // ((A, B), C) and (A, B, C) we prefix the generic args with a _ and suffix
1799 // them with a Z. Ideally we wouldn't use Z, but not many special chars are
1800 // available for use in type names.
1801 write!(w, "C{}Tuple_", tuple.elems.len()).unwrap();
1802 write!(mangled_type, "C{}Tuple_", tuple.elems.len()).unwrap();
1803 write!(mangled_tuple_type, "C{}Tuple_", tuple.elems.len()).unwrap();
1804 for elem in tuple.elems.iter() {
1805 if let syn::Type::Path(p) = elem {
1806 write_path!(p, Some(&mut mangled_tuple_type));
1807 } else { return false; }
1809 write!(w, "Z").unwrap();
1810 write!(mangled_type, "Z").unwrap();
1811 write!(mangled_tuple_type, "Z").unwrap();
1812 self.check_create_container(String::from_utf8(mangled_tuple_type).unwrap(),
1813 &format!("{}Tuple", tuple.elems.len()), tuple.elems.iter().collect(), generics, is_ref);
1815 } else if let syn::Type::Path(p_arg) = arg {
1816 write_path!(p_arg, None);
1817 } else if let syn::Type::Reference(refty) = arg {
1818 if args.len() != 1 { return false; }
1819 if let syn::Type::Path(p_arg) = &*refty.elem {
1820 write_path!(p_arg, None);
1821 } else if let syn::Type::Slice(_) = &*refty.elem {
1822 // write_c_type will actually do exactly what we want here, we just need to
1823 // make it a pointer so that its an option. Note that we cannot always convert
1824 // the Vec-as-slice (ie non-ref types) containers, so sometimes need to be able
1825 // to edit it, hence we use *mut here instead of *const.
1826 write!(w, "*mut ").unwrap();
1827 self.write_c_type(w, arg, None, true);
1828 } else { return false; }
1829 } else if let syn::Type::Array(a) = arg {
1830 if let syn::Type::Path(p_arg) = &*a.elem {
1831 let resolved = self.resolve_path(&p_arg.path, generics);
1832 if !self.is_primitive(&resolved) { return false; }
1833 if let syn::Expr::Lit(syn::ExprLit { lit: syn::Lit::Int(len), .. }) = &a.len {
1834 if self.c_type_from_path(&format!("[{}; {}]", resolved, len.base10_digits()), is_ref, ptr_for_ref).is_none() { return false; }
1835 write!(w, "_{}{}", resolved, len.base10_digits()).unwrap();
1836 write!(mangled_type, "_{}{}", resolved, len.base10_digits()).unwrap();
1837 } else { return false; }
1838 } else { return false; }
1839 } else { return false; }
1841 if self.is_transparent_container(ident, is_ref) { return true; }
1842 // Push the "end of type" Z
1843 write!(w, "Z").unwrap();
1844 write!(mangled_type, "Z").unwrap();
1846 // Make sure the type is actually defined:
1847 self.check_create_container(String::from_utf8(mangled_type).unwrap(), ident, args, generics, is_ref);
1850 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 {
1851 if !self.is_transparent_container(ident, is_ref) {
1852 write!(w, "{}::", Self::generated_container_path()).unwrap();
1854 self.write_c_mangled_container_path_intern(w, args, generics, ident, is_ref, is_mut, ptr_for_ref, false)
1857 // **********************************
1858 // *** C Type Equivalent Printing ***
1859 // **********************************
1861 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 {
1862 let full_path = match self.maybe_resolve_path(&path, generics) {
1863 Some(path) => path, None => return false };
1864 if let Some(c_type) = self.c_type_from_path(&full_path, is_ref, ptr_for_ref) {
1865 write!(w, "{}", c_type).unwrap();
1867 } else if self.crate_types.traits.get(&full_path).is_some() {
1868 if is_ref && ptr_for_ref {
1869 write!(w, "*{} crate::{}", if is_mut { "mut" } else { "const" }, full_path).unwrap();
1871 write!(w, "&{}crate::{}", if is_mut { "mut " } else { "" }, full_path).unwrap();
1873 write!(w, "crate::{}", full_path).unwrap();
1876 } else if self.crate_types.opaques.get(&full_path).is_some() || self.crate_types.mirrored_enums.get(&full_path).is_some() {
1877 if is_ref && ptr_for_ref {
1878 // ptr_for_ref implies we're returning the object, which we can't really do for
1879 // opaque or mirrored types without box'ing them, which is quite a waste, so return
1880 // the actual object itself (for opaque types we'll set the pointer to the actual
1881 // type and note that its a reference).
1882 write!(w, "crate::{}", full_path).unwrap();
1884 write!(w, "&{}crate::{}", if is_mut { "mut " } else { "" }, full_path).unwrap();
1886 write!(w, "crate::{}", full_path).unwrap();
1893 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 {
1895 syn::Type::Path(p) => {
1896 if p.qself.is_some() || p.path.leading_colon.is_some() {
1899 if let Some(full_path) = self.maybe_resolve_path(&p.path, generics) {
1900 if self.is_known_container(&full_path, is_ref) || self.is_transparent_container(&full_path, is_ref) {
1901 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);
1904 if p.path.leading_colon.is_some() { return false; }
1905 self.write_c_path_intern(w, &p.path, generics, is_ref, is_mut, ptr_for_ref)
1907 syn::Type::Reference(r) => {
1908 if let Some(lft) = &r.lifetime {
1909 if format!("{}", lft.ident) != "static" { return false; }
1911 self.write_c_type_intern(w, &*r.elem, generics, true, r.mutability.is_some(), ptr_for_ref)
1913 syn::Type::Array(a) => {
1914 if is_ref && is_mut {
1915 write!(w, "*mut [").unwrap();
1916 if !self.write_c_type_intern(w, &a.elem, generics, false, false, ptr_for_ref) { return false; }
1918 write!(w, "*const [").unwrap();
1919 if !self.write_c_type_intern(w, &a.elem, generics, false, false, ptr_for_ref) { return false; }
1921 let mut typecheck = Vec::new();
1922 if !self.write_c_type_intern(&mut typecheck, &a.elem, generics, false, false, ptr_for_ref) { return false; }
1923 if typecheck[..] != ['u' as u8, '8' as u8] { return false; }
1925 if let syn::Expr::Lit(l) = &a.len {
1926 if let syn::Lit::Int(i) = &l.lit {
1928 if let Some(ty) = self.c_type_from_path(&format!("[u8; {}]", i.base10_digits()), false, ptr_for_ref) {
1929 write!(w, "{}", ty).unwrap();
1933 write!(w, "; {}]", i).unwrap();
1939 syn::Type::Slice(s) => {
1940 if !is_ref || is_mut { return false; }
1941 if let syn::Type::Path(p) = &*s.elem {
1942 let resolved = self.resolve_path(&p.path, generics);
1943 if self.is_primitive(&resolved) {
1944 write!(w, "{}::{}slice", Self::container_templ_path(), resolved).unwrap();
1947 } else if let syn::Type::Reference(r) = &*s.elem {
1948 if let syn::Type::Path(p) = &*r.elem {
1949 // Slices with "real types" inside are mapped as the equivalent non-ref Vec
1950 let resolved = self.resolve_path(&p.path, generics);
1951 let mangled_container = if let Some(ident) = self.crate_types.opaques.get(&resolved) {
1952 format!("CVec_{}Z", ident)
1953 } else if let Some(en) = self.crate_types.mirrored_enums.get(&resolved) {
1954 format!("CVec_{}Z", en.ident)
1955 } else if let Some(id) = p.path.get_ident() {
1956 format!("CVec_{}Z", id)
1957 } else { return false; };
1958 write!(w, "{}::{}", Self::generated_container_path(), mangled_container).unwrap();
1959 self.check_create_container(mangled_container, "Vec", vec![&*r.elem], generics, false);
1964 syn::Type::Tuple(t) => {
1965 if t.elems.len() == 0 {
1968 self.write_c_mangled_container_path(w, t.elems.iter().collect(), generics,
1969 &format!("{}Tuple", t.elems.len()), is_ref, is_mut, ptr_for_ref)
1975 pub fn write_c_type<W: std::io::Write>(&mut self, w: &mut W, t: &syn::Type, generics: Option<&GenericTypes>, ptr_for_ref: bool) {
1976 assert!(self.write_c_type_intern(w, t, generics, false, false, ptr_for_ref));
1978 pub fn understood_c_path(&mut self, p: &syn::Path) -> bool {
1979 if p.leading_colon.is_some() { return false; }
1980 self.write_c_path_intern(&mut std::io::sink(), p, None, false, false, false)
1982 pub fn understood_c_type(&mut self, t: &syn::Type, generics: Option<&GenericTypes>) -> bool {
1983 self.write_c_type_intern(&mut std::io::sink(), t, generics, false, false, false)