1 // This file is Copyright its original authors, visible in version control
4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE>
5 // or the MIT license <LICENSE-MIT>, at your option.
6 // You may not use this file except in accordance with one or both of these
9 //! Printing logic for basic blocks of Rust-mapped code - parts of functions and declarations but
10 //! not the full mapping logic.
14 use proc_macro2::{TokenTree, Span};
18 /// Writes out a C++ wrapper class for the given type, which contains various utilities to access
19 /// the underlying C-mapped type safely avoiding some common memory management issues by handling
20 /// resource-freeing and prevending accidental raw copies.
21 pub fn write_cpp_wrapper(cpp_header_file: &mut File, ty: &str, has_destructor: bool) {
22 writeln!(cpp_header_file, "class {} {{", ty).unwrap();
23 writeln!(cpp_header_file, "private:").unwrap();
24 writeln!(cpp_header_file, "\tLDK{} self;", ty).unwrap();
25 writeln!(cpp_header_file, "public:").unwrap();
26 writeln!(cpp_header_file, "\t{}(const {}&) = delete;", ty, ty).unwrap();
27 writeln!(cpp_header_file, "\t{}({}&& o) : self(o.self) {{ memset(&o, 0, sizeof({})); }}", ty, ty, ty).unwrap();
28 writeln!(cpp_header_file, "\t{}(LDK{}&& m_self) : self(m_self) {{ memset(&m_self, 0, sizeof(LDK{})); }}", ty, ty, ty).unwrap();
29 writeln!(cpp_header_file, "\toperator LDK{}() && {{ LDK{} res = self; memset(&self, 0, sizeof(LDK{})); return res; }}", ty, ty, ty).unwrap();
31 writeln!(cpp_header_file, "\t~{}() {{ {}_free(self); }}", ty, ty).unwrap();
32 writeln!(cpp_header_file, "\t{}& operator=({}&& o) {{ {}_free(self); self = o.self; memset(&o, 0, sizeof({})); return *this; }}", ty, ty, ty, ty).unwrap();
34 writeln!(cpp_header_file, "\t{}& operator=({}&& o) {{ self = o.self; memset(&o, 0, sizeof({})); return *this; }}", ty, ty, ty).unwrap();
36 writeln!(cpp_header_file, "\tLDK{}* operator &() {{ return &self; }}", ty).unwrap();
37 writeln!(cpp_header_file, "\tLDK{}* operator ->() {{ return &self; }}", ty).unwrap();
38 writeln!(cpp_header_file, "\tconst LDK{}* operator &() const {{ return &self; }}", ty).unwrap();
39 writeln!(cpp_header_file, "\tconst LDK{}* operator ->() const {{ return &self; }}", ty).unwrap();
40 writeln!(cpp_header_file, "}};").unwrap();
43 /// Writes out a C-callable concrete Result<A, B> struct and utility methods
44 pub fn write_result_block<W: std::io::Write>(w: &mut W, mangled_container: &str, ok_type: &str, err_type: &str, clonable: bool) {
45 writeln!(w, "#[repr(C)]").unwrap();
46 writeln!(w, "pub union {}Ptr {{", mangled_container).unwrap();
48 writeln!(w, "\tpub result: *mut {},", ok_type).unwrap();
50 writeln!(w, "\t/// Note that this value is always NULL, as there are no contents in the OK variant").unwrap();
51 writeln!(w, "\tpub result: *mut std::ffi::c_void,").unwrap();
54 writeln!(w, "\tpub err: *mut {},", err_type).unwrap();
56 writeln!(w, "\t/// Note that this value is always NULL, as there are no contents in the Err variant").unwrap();
57 writeln!(w, "\tpub err: *mut std::ffi::c_void,").unwrap();
59 writeln!(w, "}}").unwrap();
60 writeln!(w, "#[repr(C)]").unwrap();
61 writeln!(w, "pub struct {} {{", mangled_container).unwrap();
62 writeln!(w, "\tpub contents: {}Ptr,", mangled_container).unwrap();
63 writeln!(w, "\tpub result_ok: bool,").unwrap();
64 writeln!(w, "}}").unwrap();
66 writeln!(w, "#[no_mangle]").unwrap();
68 writeln!(w, "pub extern \"C\" fn {}_ok(o: {}) -> {} {{", mangled_container, ok_type, mangled_container).unwrap();
70 writeln!(w, "pub extern \"C\" fn {}_ok() -> {} {{", mangled_container, mangled_container).unwrap();
72 writeln!(w, "\t{} {{", mangled_container).unwrap();
73 writeln!(w, "\t\tcontents: {}Ptr {{", mangled_container).unwrap();
75 writeln!(w, "\t\t\tresult: Box::into_raw(Box::new(o)),").unwrap();
77 writeln!(w, "\t\t\tresult: std::ptr::null_mut(),").unwrap();
79 writeln!(w, "\t\t}},").unwrap();
80 writeln!(w, "\t\tresult_ok: true,").unwrap();
81 writeln!(w, "\t}}").unwrap();
82 writeln!(w, "}}").unwrap();
84 writeln!(w, "#[no_mangle]").unwrap();
86 writeln!(w, "pub extern \"C\" fn {}_err(e: {}) -> {} {{", mangled_container, err_type, mangled_container).unwrap();
88 writeln!(w, "pub extern \"C\" fn {}_err() -> {} {{", mangled_container, mangled_container).unwrap();
90 writeln!(w, "\t{} {{", mangled_container).unwrap();
91 writeln!(w, "\t\tcontents: {}Ptr {{", mangled_container).unwrap();
93 writeln!(w, "\t\t\terr: Box::into_raw(Box::new(e)),").unwrap();
95 writeln!(w, "\t\t\terr: std::ptr::null_mut(),").unwrap();
97 writeln!(w, "\t\t}},").unwrap();
98 writeln!(w, "\t\tresult_ok: false,").unwrap();
99 writeln!(w, "\t}}").unwrap();
100 writeln!(w, "}}").unwrap();
102 writeln!(w, "#[no_mangle]").unwrap();
103 writeln!(w, "pub extern \"C\" fn {}_free(_res: {}) {{ }}", mangled_container, mangled_container).unwrap();
104 writeln!(w, "impl Drop for {} {{", mangled_container).unwrap();
105 writeln!(w, "\tfn drop(&mut self) {{").unwrap();
106 writeln!(w, "\t\tif self.result_ok {{").unwrap();
108 writeln!(w, "\t\t\tif unsafe {{ !(self.contents.result as *mut ()).is_null() }} {{").unwrap();
109 writeln!(w, "\t\t\t\tlet _ = unsafe {{ Box::from_raw(self.contents.result) }};").unwrap();
110 writeln!(w, "\t\t\t}}").unwrap();
112 writeln!(w, "\t\t}} else {{").unwrap();
113 if err_type != "()" {
114 writeln!(w, "\t\t\tif unsafe {{ !(self.contents.err as *mut ()).is_null() }} {{").unwrap();
115 writeln!(w, "\t\t\t\tlet _ = unsafe {{ Box::from_raw(self.contents.err) }};").unwrap();
116 writeln!(w, "\t\t\t}}").unwrap();
118 writeln!(w, "\t\t}}").unwrap();
119 writeln!(w, "\t}}").unwrap();
120 writeln!(w, "}}").unwrap();
122 // TODO: Templates should use () now that they can, too
123 let templ_ok_type = if ok_type != "()" { ok_type } else { "u8" };
124 let templ_err_type = if err_type != "()" { err_type } else { "u8" };
126 writeln!(w, "impl From<crate::c_types::CResultTempl<{}, {}>> for {} {{", templ_ok_type, templ_err_type, mangled_container).unwrap();
127 writeln!(w, "\tfn from(mut o: crate::c_types::CResultTempl<{}, {}>) -> Self {{", templ_ok_type, templ_err_type).unwrap();
128 writeln!(w, "\t\tlet contents = if o.result_ok {{").unwrap();
130 writeln!(w, "\t\t\tlet result = unsafe {{ o.contents.result }};").unwrap();
131 writeln!(w, "\t\t\tunsafe {{ o.contents.result = std::ptr::null_mut() }};").unwrap();
132 writeln!(w, "\t\t\t{}Ptr {{ result }}", mangled_container).unwrap();
134 writeln!(w, "\t\t\tlet _ = unsafe {{ Box::from_raw(o.contents.result) }};").unwrap();
135 writeln!(w, "\t\t\to.contents.result = std::ptr::null_mut();").unwrap();
136 writeln!(w, "\t\t\t{}Ptr {{ result: std::ptr::null_mut() }}", mangled_container).unwrap();
138 writeln!(w, "\t\t}} else {{").unwrap();
139 if err_type != "()" {
140 writeln!(w, "\t\t\tlet err = unsafe {{ o.contents.err }};").unwrap();
141 writeln!(w, "\t\t\tunsafe {{ o.contents.err = std::ptr::null_mut(); }}").unwrap();
142 writeln!(w, "\t\t\t{}Ptr {{ err }}", mangled_container).unwrap();
144 writeln!(w, "\t\t\tlet _ = unsafe {{ Box::from_raw(o.contents.err) }};").unwrap();
145 writeln!(w, "\t\t\to.contents.err = std::ptr::null_mut();").unwrap();
146 writeln!(w, "\t\t\t{}Ptr {{ err: std::ptr::null_mut() }}", mangled_container).unwrap();
148 writeln!(w, "\t\t}};").unwrap();
149 writeln!(w, "\t\tSelf {{").unwrap();
150 writeln!(w, "\t\t\tcontents,").unwrap();
151 writeln!(w, "\t\t\tresult_ok: o.result_ok,").unwrap();
152 writeln!(w, "\t\t}}").unwrap();
153 writeln!(w, "\t}}").unwrap();
154 writeln!(w, "}}").unwrap();
157 writeln!(w, "impl Clone for {} {{", mangled_container).unwrap();
158 writeln!(w, "\tfn clone(&self) -> Self {{").unwrap();
159 writeln!(w, "\t\tif self.result_ok {{").unwrap();
160 writeln!(w, "\t\t\tSelf {{ result_ok: true, contents: {}Ptr {{", mangled_container).unwrap();
162 writeln!(w, "\t\t\t\tresult: Box::into_raw(Box::new(<{}>::clone(unsafe {{ &*self.contents.result }})))", ok_type).unwrap();
164 writeln!(w, "\t\t\t\tresult: std::ptr::null_mut()").unwrap();
166 writeln!(w, "\t\t\t}} }}").unwrap();
167 writeln!(w, "\t\t}} else {{").unwrap();
168 writeln!(w, "\t\t\tSelf {{ result_ok: false, contents: {}Ptr {{", mangled_container).unwrap();
169 if err_type != "()" {
170 writeln!(w, "\t\t\t\terr: Box::into_raw(Box::new(<{}>::clone(unsafe {{ &*self.contents.err }})))", err_type).unwrap();
172 writeln!(w, "\t\t\t\terr: std::ptr::null_mut()").unwrap();
174 writeln!(w, "\t\t\t}} }}").unwrap();
175 writeln!(w, "\t\t}}").unwrap();
176 writeln!(w, "\t}}").unwrap();
177 writeln!(w, "}}").unwrap();
178 writeln!(w, "#[no_mangle]").unwrap();
179 writeln!(w, "pub extern \"C\" fn {}_clone(orig: &{}) -> {} {{ orig.clone() }}", mangled_container, mangled_container, mangled_container).unwrap();
183 /// Writes out a C-callable concrete Vec<A> struct and utility methods
184 pub fn write_vec_block<W: std::io::Write>(w: &mut W, mangled_container: &str, inner_type: &str, clonable: bool) {
185 writeln!(w, "#[repr(C)]").unwrap();
186 writeln!(w, "pub struct {} {{", mangled_container).unwrap();
187 writeln!(w, "\tpub data: *mut {},", inner_type).unwrap();
188 writeln!(w, "\tpub datalen: usize").unwrap();
189 writeln!(w, "}}").unwrap();
191 writeln!(w, "impl {} {{", mangled_container).unwrap();
192 writeln!(w, "\t#[allow(unused)] pub(crate) fn into_rust(&mut self) -> Vec<{}> {{", inner_type).unwrap();
193 writeln!(w, "\t\tif self.datalen == 0 {{ return Vec::new(); }}").unwrap();
194 writeln!(w, "\t\tlet ret = unsafe {{ Box::from_raw(std::slice::from_raw_parts_mut(self.data, self.datalen)) }}.into();").unwrap();
195 writeln!(w, "\t\tself.data = std::ptr::null_mut();").unwrap();
196 writeln!(w, "\t\tself.datalen = 0;").unwrap();
197 writeln!(w, "\t\tret").unwrap();
198 writeln!(w, "\t}}").unwrap();
199 writeln!(w, "\t#[allow(unused)] pub(crate) fn as_slice(&self) -> &[{}] {{", inner_type).unwrap();
200 writeln!(w, "\t\tunsafe {{ std::slice::from_raw_parts_mut(self.data, self.datalen) }}").unwrap();
201 writeln!(w, "\t}}").unwrap();
202 writeln!(w, "}}").unwrap();
204 writeln!(w, "impl From<Vec<{}>> for {} {{", inner_type, mangled_container).unwrap();
205 writeln!(w, "\tfn from(v: Vec<{}>) -> Self {{", inner_type).unwrap();
206 writeln!(w, "\t\tlet datalen = v.len();").unwrap();
207 writeln!(w, "\t\tlet data = Box::into_raw(v.into_boxed_slice());").unwrap();
208 writeln!(w, "\t\tSelf {{ datalen, data: unsafe {{ (*data).as_mut_ptr() }} }}").unwrap();
209 writeln!(w, "\t}}").unwrap();
210 writeln!(w, "}}").unwrap();
212 writeln!(w, "#[no_mangle]").unwrap();
213 writeln!(w, "pub extern \"C\" fn {}_free(_res: {}) {{ }}", mangled_container, mangled_container).unwrap();
214 writeln!(w, "impl Drop for {} {{", mangled_container).unwrap();
215 writeln!(w, "\tfn drop(&mut self) {{").unwrap();
216 writeln!(w, "\t\tif self.datalen == 0 {{ return; }}").unwrap();
217 writeln!(w, "\t\tunsafe {{ Box::from_raw(std::slice::from_raw_parts_mut(self.data, self.datalen)) }};").unwrap();
218 writeln!(w, "\t}}").unwrap();
219 writeln!(w, "}}").unwrap();
221 writeln!(w, "impl Clone for {} {{", mangled_container).unwrap();
222 writeln!(w, "\tfn clone(&self) -> Self {{").unwrap();
223 writeln!(w, "\t\tlet mut res = Vec::new();").unwrap();
224 writeln!(w, "\t\tif self.datalen == 0 {{ return Self::from(res); }}").unwrap();
225 writeln!(w, "\t\tres.extend_from_slice(unsafe {{ std::slice::from_raw_parts_mut(self.data, self.datalen) }});").unwrap();
226 writeln!(w, "\t\tSelf::from(res)").unwrap();
227 writeln!(w, "\t}}").unwrap();
228 writeln!(w, "}}").unwrap();
232 /// Writes out a C-callable concrete (A, B, ...) struct and utility methods
233 pub fn write_tuple_block<W: std::io::Write>(w: &mut W, mangled_container: &str, types: &[String], clonable: bool) {
234 writeln!(w, "#[repr(C)]").unwrap();
235 writeln!(w, "pub struct {} {{", mangled_container).unwrap();
236 for (idx, ty) in types.iter().enumerate() {
237 writeln!(w, "\tpub {}: {},", ('a' as u8 + idx as u8) as char, ty).unwrap();
239 writeln!(w, "}}").unwrap();
241 let mut tuple_str = "(".to_owned();
242 for (idx, ty) in types.iter().enumerate() {
243 if idx != 0 { tuple_str += ", "; }
248 writeln!(w, "impl From<{}> for {} {{", tuple_str, mangled_container).unwrap();
249 writeln!(w, "\tfn from (tup: {}) -> Self {{", tuple_str).unwrap();
250 writeln!(w, "\t\tSelf {{").unwrap();
251 for idx in 0..types.len() {
252 writeln!(w, "\t\t\t{}: tup.{},", ('a' as u8 + idx as u8) as char, idx).unwrap();
254 writeln!(w, "\t\t}}").unwrap();
255 writeln!(w, "\t}}").unwrap();
256 writeln!(w, "}}").unwrap();
257 writeln!(w, "impl {} {{", mangled_container).unwrap();
258 writeln!(w, "\t#[allow(unused)] pub(crate) fn to_rust(mut self) -> {} {{", tuple_str).unwrap();
259 write!(w, "\t\t(").unwrap();
260 for idx in 0..types.len() {
261 write!(w, "{}self.{}", if idx != 0 {", "} else {""}, ('a' as u8 + idx as u8) as char).unwrap();
263 writeln!(w, ")").unwrap();
264 writeln!(w, "\t}}").unwrap();
265 writeln!(w, "}}").unwrap();
268 writeln!(w, "impl Clone for {} {{", mangled_container).unwrap();
269 writeln!(w, "\tfn clone(&self) -> Self {{").unwrap();
270 writeln!(w, "\t\tSelf {{").unwrap();
271 for idx in 0..types.len() {
272 writeln!(w, "\t\t\t{}: self.{}.clone(),", ('a' as u8 + idx as u8) as char, ('a' as u8 + idx as u8) as char).unwrap();
274 writeln!(w, "\t\t}}").unwrap();
275 writeln!(w, "\t}}").unwrap();
276 writeln!(w, "}}").unwrap();
277 writeln!(w, "#[no_mangle]").unwrap();
278 writeln!(w, "pub extern \"C\" fn {}_clone(orig: &{}) -> {} {{ orig.clone() }}", mangled_container, mangled_container, mangled_container).unwrap();
281 write!(w, "#[no_mangle]\npub extern \"C\" fn {}_new(", mangled_container).unwrap();
282 for (idx, gen) in types.iter().enumerate() {
283 write!(w, "{}{}: ", if idx != 0 { ", " } else { "" }, ('a' as u8 + idx as u8) as char).unwrap();
284 //if !self.write_c_type_intern(&mut created_container, gen, generics, false, false, false) { return false; }
285 write!(w, "{}", gen).unwrap();
287 writeln!(w, ") -> {} {{", mangled_container).unwrap();
288 write!(w, "\t{} {{ ", mangled_container).unwrap();
289 for idx in 0..types.len() {
290 write!(w, "{}, ", ('a' as u8 + idx as u8) as char).unwrap();
292 writeln!(w, "}}\n}}\n").unwrap();
294 writeln!(w, "#[no_mangle]").unwrap();
295 writeln!(w, "pub extern \"C\" fn {}_free(_res: {}) {{ }}", mangled_container, mangled_container).unwrap();
298 /// Prints the docs from a given attribute list unless its tagged no export
299 pub fn writeln_docs<W: std::io::Write>(w: &mut W, attrs: &[syn::Attribute], prefix: &str) {
300 for attr in attrs.iter() {
301 let tokens_clone = attr.tokens.clone();
302 let mut token_iter = tokens_clone.into_iter();
303 if let Some(token) = token_iter.next() {
305 TokenTree::Punct(c) if c.as_char() == '=' => {
306 // syn gets '=' from '///' or '//!' as it is syntax for #[doc = ""]
308 TokenTree::Group(_) => continue, // eg #[derive()]
309 _ => unimplemented!(),
313 syn::AttrStyle::Inner(_) => {
314 match token_iter.next().unwrap() {
315 TokenTree::Literal(lit) => {
316 // Drop the first and last chars from lit as they are always "
317 let doc = format!("{}", lit);
318 writeln!(w, "{}//!{}", prefix, &doc[1..doc.len() - 1]).unwrap();
320 _ => unimplemented!(),
323 syn::AttrStyle::Outer => {
324 match token_iter.next().unwrap() {
325 TokenTree::Literal(lit) => {
326 // Drop the first and last chars from lit as they are always "
327 let doc = format!("{}", lit);
328 writeln!(w, "{}///{}", prefix, &doc[1..doc.len() - 1]).unwrap();
330 _ => unimplemented!(),
337 /// Print the parameters in a method declaration, starting after the open parenthesis, through and
338 /// including the closing parenthesis and return value, but not including the open bracket or any
339 /// trailing semicolons.
341 /// Usable both for a function definition and declaration.
343 /// this_param is used when returning Self or accepting a self parameter, and should be the
344 /// concrete, mapped type.
345 pub fn write_method_params<W: std::io::Write>(w: &mut W, sig: &syn::Signature, this_param: &str, types: &mut TypeResolver, generics: Option<&GenericTypes>, self_ptr: bool, fn_decl: bool) {
346 if sig.constness.is_some() || sig.asyncness.is_some() || sig.unsafety.is_some() ||
347 sig.abi.is_some() || sig.variadic.is_some() {
350 if sig.generics.lt_token.is_some() {
351 for generic in sig.generics.params.iter() {
353 syn::GenericParam::Type(_)|syn::GenericParam::Lifetime(_) => {
354 // We ignore these, if they're not on skipped args, we'll blow up
355 // later, and lifetimes we just hope the C client enforces.
357 _ => unimplemented!(),
362 let mut first_arg = true;
363 let mut num_unused = 0;
364 for inp in sig.inputs.iter() {
366 syn::FnArg::Receiver(recv) => {
367 if !recv.attrs.is_empty() || recv.reference.is_none() { unimplemented!(); }
368 write!(w, "this_arg: {}{}",
369 match (self_ptr, recv.mutability.is_some()) {
370 (true, true) => "*mut ",
371 (true, false) => "*const ",
372 (false, true) => "&mut ",
373 (false, false) => "&",
374 }, this_param).unwrap();
378 syn::FnArg::Typed(arg) => {
379 if types.skip_arg(&*arg.ty, generics) { continue; }
380 if !arg.attrs.is_empty() { unimplemented!(); }
381 // First get the c type so that we can check if it ends up being a reference:
382 let mut c_type = Vec::new();
383 types.write_c_type(&mut c_type, &*arg.ty, generics, false);
385 syn::Pat::Ident(ident) => {
386 if !ident.attrs.is_empty() || ident.subpat.is_some() {
389 write!(w, "{}{}{}: ", if first_arg { "" } else { ", " }, if !fn_decl || c_type[0] == '&' as u8 || c_type[0] == '*' as u8 { "" } else { "mut " }, ident.ident).unwrap();
392 syn::Pat::Wild(wild) => {
393 if !wild.attrs.is_empty() { unimplemented!(); }
394 write!(w, "{}unused_{}: ", if first_arg { "" } else { ", " }, num_unused).unwrap();
397 _ => unimplemented!(),
399 w.write(&c_type).unwrap();
403 write!(w, ")").unwrap();
405 syn::ReturnType::Type(_, rtype) => {
406 write!(w, " -> ").unwrap();
407 if let Some(mut remaining_path) = first_seg_self(&*rtype) {
408 if remaining_path.next().is_none() {
409 write!(w, "{}", this_param).unwrap();
413 if let syn::Type::Reference(r) = &**rtype {
414 // We can't return a reference, cause we allocate things on the stack.
415 types.write_c_type(w, &*r.elem, generics, true);
417 types.write_c_type(w, &*rtype, generics, true);
424 /// Print the main part of a method declaration body, starting with a newline after the function
425 /// open bracket and converting each function parameter to or from C-mapped types. Ends with "let
426 /// mut ret = " assuming the next print will be the unmapped Rust function to call followed by the
427 /// parameters we mapped to/from C here.
428 pub fn write_method_var_decl_body<W: std::io::Write>(w: &mut W, sig: &syn::Signature, extra_indent: &str, types: &TypeResolver, generics: Option<&GenericTypes>, to_c: bool) {
429 let mut num_unused = 0;
430 for inp in sig.inputs.iter() {
432 syn::FnArg::Receiver(_) => {},
433 syn::FnArg::Typed(arg) => {
434 if types.skip_arg(&*arg.ty, generics) { continue; }
435 if !arg.attrs.is_empty() { unimplemented!(); }
436 macro_rules! write_new_var {
437 ($ident: expr, $ty: expr) => {
439 if types.write_to_c_conversion_new_var(w, &$ident, &$ty, generics, false) {
440 write!(w, "\n\t{}", extra_indent).unwrap();
443 if types.write_from_c_conversion_new_var(w, &$ident, &$ty, generics) {
444 write!(w, "\n\t{}", extra_indent).unwrap();
450 syn::Pat::Ident(ident) => {
451 if !ident.attrs.is_empty() || ident.subpat.is_some() {
454 write_new_var!(ident.ident, *arg.ty);
456 syn::Pat::Wild(w) => {
457 if !w.attrs.is_empty() { unimplemented!(); }
458 write_new_var!(syn::Ident::new(&format!("unused_{}", num_unused), Span::call_site()), *arg.ty);
461 _ => unimplemented!(),
467 syn::ReturnType::Type(_, _) => {
468 write!(w, "let mut ret = ").unwrap();
474 /// Prints the parameters in a method call, starting after the open parenthesis and ending with a
475 /// final return statement returning the method's result. Should be followed by a single closing
478 /// The return value is expected to be bound to a variable named `ret` which is available after a
479 /// method-call-ending semicolon.
480 pub fn write_method_call_params<W: std::io::Write>(w: &mut W, sig: &syn::Signature, extra_indent: &str, types: &TypeResolver, generics: Option<&GenericTypes>, this_type: &str, to_c: bool) {
481 let mut first_arg = true;
482 let mut num_unused = 0;
483 for inp in sig.inputs.iter() {
485 syn::FnArg::Receiver(recv) => {
486 if !recv.attrs.is_empty() || recv.reference.is_none() { unimplemented!(); }
488 write!(w, "self.this_arg").unwrap();
492 syn::FnArg::Typed(arg) => {
493 if types.skip_arg(&*arg.ty, generics) {
496 write!(w, ", ").unwrap();
499 types.no_arg_to_rust(w, &*arg.ty, generics);
503 if !arg.attrs.is_empty() { unimplemented!(); }
504 macro_rules! write_ident {
507 write!(w, ", ").unwrap();
511 types.write_to_c_conversion_inline_prefix(w, &*arg.ty, generics, false);
512 write!(w, "{}", $ident).unwrap();
513 types.write_to_c_conversion_inline_suffix(w, &*arg.ty, generics, false);
515 types.write_from_c_conversion_prefix(w, &*arg.ty, generics);
516 write!(w, "{}", $ident).unwrap();
517 types.write_from_c_conversion_suffix(w, &*arg.ty, generics);
522 syn::Pat::Ident(ident) => {
523 if !ident.attrs.is_empty() || ident.subpat.is_some() {
526 write_ident!(ident.ident);
528 syn::Pat::Wild(w) => {
529 if !w.attrs.is_empty() { unimplemented!(); }
530 write_ident!(format!("unused_{}", num_unused));
533 _ => unimplemented!(),
538 write!(w, ")").unwrap();
540 syn::ReturnType::Type(_, rtype) => {
541 write!(w, ";\n\t{}", extra_indent).unwrap();
543 let self_segs_iter = first_seg_self(&*rtype);
544 if to_c && first_seg_self(&*rtype).is_some() {
545 // Assume rather blindly that we're returning an associated trait from a C fn call to a Rust trait object.
546 write!(w, "ret").unwrap();
547 } else if !to_c && self_segs_iter.is_some() && self_segs_iter.unwrap().next().is_none() {
548 // If we're returning "Self" (and not "Self::X"), just do it manually
549 write!(w, "{} {{ inner: Box::into_raw(Box::new(ret)), is_owned: true }}", this_type).unwrap();
551 let new_var = types.write_from_c_conversion_new_var(w, &syn::Ident::new("ret", Span::call_site()), rtype, generics);
553 write!(w, "\n\t{}", extra_indent).unwrap();
555 types.write_from_c_conversion_prefix(w, &*rtype, generics);
556 write!(w, "ret").unwrap();
557 types.write_from_c_conversion_suffix(w, &*rtype, generics);
559 let ret_returned = if let syn::Type::Reference(_) = &**rtype { true } else { false };
560 let new_var = types.write_to_c_conversion_new_var(w, &syn::Ident::new("ret", Span::call_site()), &rtype, generics, true);
562 write!(w, "\n\t{}", extra_indent).unwrap();
564 types.write_to_c_conversion_inline_prefix(w, &rtype, generics, true);
565 write!(w, "{}ret", if ret_returned && !new_var { "*" } else { "" }).unwrap();
566 types.write_to_c_conversion_inline_suffix(w, &rtype, generics, true);
573 /// Prints concrete generic parameters for a struct/trait/function, including the less-than and
574 /// greater-than symbols, if any generic parameters are defined.
575 pub fn maybe_write_generics<W: std::io::Write>(w: &mut W, generics: &syn::Generics, types: &TypeResolver, concrete_lifetimes: bool) {
576 let mut gen_types = GenericTypes::new();
577 assert!(gen_types.learn_generics(generics, types));
578 if !generics.params.is_empty() {
579 write!(w, "<").unwrap();
580 for (idx, generic) in generics.params.iter().enumerate() {
582 syn::GenericParam::Type(type_param) => {
583 let mut printed_param = false;
584 for bound in type_param.bounds.iter() {
585 if let syn::TypeParamBound::Trait(trait_bound) = bound {
586 assert_simple_bound(&trait_bound);
587 write!(w, "{}{}", if idx != 0 { ", " } else { "" }, gen_types.maybe_resolve_ident(&type_param.ident).unwrap()).unwrap();
589 unimplemented!("Can't print generic params that have multiple non-lifetime bounds");
591 printed_param = true;
595 syn::GenericParam::Lifetime(lt) => {
596 if concrete_lifetimes {
597 write!(w, "'static").unwrap();
599 write!(w, "{}'{}", if idx != 0 { ", " } else { "" }, lt.lifetime.ident).unwrap();
602 _ => unimplemented!(),
605 write!(w, ">").unwrap();