use crate::syntax::attrs::OtherAttrs;
use crate::syntax::cfg::CfgExpr;
use crate::syntax::discriminant::DiscriminantSet;
use crate::syntax::file::{Item, ItemForeignMod};
use crate::syntax::report::Errors;
use crate::syntax::Atom::*;
use crate::syntax::{
attrs, error, Api, Array, Derive, Doc, Enum, EnumRepr, ExternFn, ExternType, ForeignName, Impl,
Include, IncludeKind, Lang, Lifetimes, NamedType, Namespace, Pair, Ptr, Receiver, Ref,
Signature, SliceRef, Struct, Ty1, Type, TypeAlias, Var, Variant,
};
use proc_macro2::{Delimiter, Group, Span, TokenStream, TokenTree};
use quote::{format_ident, quote, quote_spanned};
use std::mem;
use syn::parse::{ParseStream, Parser};
use syn::punctuated::Punctuated;
use syn::{
Abi, Attribute, Error, Expr, Fields, FnArg, ForeignItem, ForeignItemFn, ForeignItemType,
GenericArgument, GenericParam, Generics, Ident, ItemEnum, ItemImpl, ItemStruct, Lit, LitStr,
Pat, PathArguments, Result, ReturnType, Signature as RustSignature, Token, TraitBound,
TraitBoundModifier, Type as RustType, TypeArray, TypeBareFn, TypeParamBound, TypePath, TypePtr,
TypeReference, Variant as RustVariant, Visibility,
};
pub(crate) mod kw {
syn::custom_keyword!(Pin);
syn::custom_keyword!(Result);
}
pub(crate) fn parse_items(
cx: &mut Errors,
items: Vec<Item>,
trusted: bool,
namespace: &Namespace,
) -> Vec<Api> {
let mut apis = Vec::new();
for item in items {
match item {
Item::Struct(item) => match parse_struct(cx, item, namespace) {
Ok(strct) => apis.push(strct),
Err(err) => cx.push(err),
},
Item::Enum(item) => apis.push(parse_enum(cx, item, namespace)),
Item::ForeignMod(foreign_mod) => {
parse_foreign_mod(cx, foreign_mod, &mut apis, trusted, namespace);
}
Item::Impl(item) => match parse_impl(cx, item) {
Ok(imp) => apis.push(imp),
Err(err) => cx.push(err),
},
Item::Use(item) => cx.error(item, error::USE_NOT_ALLOWED),
Item::Other(item) => cx.error(item, "unsupported item"),
}
}
apis
}
fn parse_struct(cx: &mut Errors, mut item: ItemStruct, namespace: &Namespace) -> Result<Api> {
let mut cfg = CfgExpr::Unconditional;
let mut doc = Doc::new();
let mut derives = Vec::new();
let mut namespace = namespace.clone();
let mut cxx_name = None;
let mut rust_name = None;
let attrs = attrs::parse(
cx,
mem::take(&mut item.attrs),
attrs::Parser {
cfg: Some(&mut cfg),
doc: Some(&mut doc),
derives: Some(&mut derives),
namespace: Some(&mut namespace),
cxx_name: Some(&mut cxx_name),
rust_name: Some(&mut rust_name),
..Default::default()
},
);
let named_fields = match item.fields {
Fields::Named(fields) => fields,
Fields::Unit => return Err(Error::new_spanned(item, "unit structs are not supported")),
Fields::Unnamed(_) => {
return Err(Error::new_spanned(item, "tuple structs are not supported"));
}
};
let mut lifetimes = Punctuated::new();
let mut has_unsupported_generic_param = false;
for pair in item.generics.params.into_pairs() {
let (param, punct) = pair.into_tuple();
match param {
GenericParam::Lifetime(param) => {
if !param.bounds.is_empty() && !has_unsupported_generic_param {
let msg = "lifetime parameter with bounds is not supported yet";
cx.error(¶m, msg);
has_unsupported_generic_param = true;
}
lifetimes.push_value(param.lifetime);
if let Some(punct) = punct {
lifetimes.push_punct(punct);
}
}
GenericParam::Type(param) => {
if !has_unsupported_generic_param {
let msg = "struct with generic type parameter is not supported yet";
cx.error(¶m, msg);
has_unsupported_generic_param = true;
}
}
GenericParam::Const(param) => {
if !has_unsupported_generic_param {
let msg = "struct with const generic parameter is not supported yet";
cx.error(¶m, msg);
has_unsupported_generic_param = true;
}
}
}
}
if let Some(where_clause) = &item.generics.where_clause {
cx.error(
where_clause,
"struct with where-clause is not supported yet",
);
}
let mut fields = Vec::new();
for field in named_fields.named {
let ident = field.ident.unwrap();
let mut cfg = CfgExpr::Unconditional;
let mut doc = Doc::new();
let mut cxx_name = None;
let mut rust_name = None;
let attrs = attrs::parse(
cx,
field.attrs,
attrs::Parser {
cfg: Some(&mut cfg),
doc: Some(&mut doc),
cxx_name: Some(&mut cxx_name),
rust_name: Some(&mut rust_name),
..Default::default()
},
);
let ty = match parse_type(&field.ty) {
Ok(ty) => ty,
Err(err) => {
cx.push(err);
continue;
}
};
let visibility = visibility_pub(&field.vis, ident.span());
let name = pair(Namespace::default(), &ident, cxx_name, rust_name);
let colon_token = field.colon_token.unwrap();
fields.push(Var {
cfg,
doc,
attrs,
visibility,
name,
colon_token,
ty,
});
}
let struct_token = item.struct_token;
let visibility = visibility_pub(&item.vis, struct_token.span);
let name = pair(namespace, &item.ident, cxx_name, rust_name);
let generics = Lifetimes {
lt_token: item.generics.lt_token,
lifetimes,
gt_token: item.generics.gt_token,
};
let brace_token = named_fields.brace_token;
Ok(Api::Struct(Struct {
cfg,
doc,
derives,
attrs,
visibility,
struct_token,
name,
generics,
brace_token,
fields,
}))
}
fn parse_enum(cx: &mut Errors, item: ItemEnum, namespace: &Namespace) -> Api {
let mut cfg = CfgExpr::Unconditional;
let mut doc = Doc::new();
let mut derives = Vec::new();
let mut repr = None;
let mut namespace = namespace.clone();
let mut cxx_name = None;
let mut rust_name = None;
let mut variants_from_header = None;
let attrs = attrs::parse(
cx,
item.attrs,
attrs::Parser {
cfg: Some(&mut cfg),
doc: Some(&mut doc),
derives: Some(&mut derives),
repr: Some(&mut repr),
namespace: Some(&mut namespace),
cxx_name: Some(&mut cxx_name),
rust_name: Some(&mut rust_name),
variants_from_header: Some(&mut variants_from_header),
..Default::default()
},
);
if !item.generics.params.is_empty() {
let vis = &item.vis;
let enum_token = item.enum_token;
let ident = &item.ident;
let generics = &item.generics;
let span = quote!(#vis #enum_token #ident #generics);
cx.error(span, "enum with generic parameters is not supported");
} else if let Some(where_clause) = &item.generics.where_clause {
cx.error(where_clause, "enum with where-clause is not supported");
}
let mut variants = Vec::new();
let mut discriminants = DiscriminantSet::new(repr);
for variant in item.variants {
match parse_variant(cx, variant, &mut discriminants) {
Ok(variant) => variants.push(variant),
Err(err) => cx.push(err),
}
}
let enum_token = item.enum_token;
let visibility = visibility_pub(&item.vis, enum_token.span);
let brace_token = item.brace_token;
let explicit_repr = repr.is_some();
let mut repr = U8;
match discriminants.inferred_repr() {
Ok(inferred) => repr = inferred,
Err(err) => {
let span = quote_spanned!(brace_token.span=> #enum_token {});
cx.error(span, err);
variants.clear();
}
}
let name = pair(namespace, &item.ident, cxx_name, rust_name);
let repr_ident = Ident::new(repr.as_ref(), Span::call_site());
let repr_type = Type::Ident(NamedType::new(repr_ident));
let repr = EnumRepr::Native {
atom: repr,
repr_type,
};
let generics = Lifetimes {
lt_token: None,
lifetimes: Punctuated::new(),
gt_token: None,
};
let variants_from_header_attr = variants_from_header;
let variants_from_header = variants_from_header_attr.is_some();
Api::Enum(Enum {
cfg,
doc,
derives,
attrs,
visibility,
enum_token,
name,
generics,
brace_token,
variants,
variants_from_header,
variants_from_header_attr,
repr,
explicit_repr,
})
}
fn parse_variant(
cx: &mut Errors,
mut variant: RustVariant,
discriminants: &mut DiscriminantSet,
) -> Result<Variant> {
let mut cfg = CfgExpr::Unconditional;
let mut doc = Doc::new();
let mut cxx_name = None;
let mut rust_name = None;
let attrs = attrs::parse(
cx,
mem::take(&mut variant.attrs),
attrs::Parser {
cfg: Some(&mut cfg),
doc: Some(&mut doc),
cxx_name: Some(&mut cxx_name),
rust_name: Some(&mut rust_name),
..Default::default()
},
);
match variant.fields {
Fields::Unit => {}
_ => {
let msg = "enums with data are not supported yet";
return Err(Error::new_spanned(variant, msg));
}
}
let expr = variant.discriminant.as_ref().map(|(_, expr)| expr);
let try_discriminant = match &expr {
Some(lit) => discriminants.insert(lit),
None => discriminants.insert_next(),
};
let discriminant = match try_discriminant {
Ok(discriminant) => discriminant,
Err(err) => return Err(Error::new_spanned(variant, err)),
};
let name = pair(Namespace::ROOT, &variant.ident, cxx_name, rust_name);
let expr = variant.discriminant.map(|(_, expr)| expr);
Ok(Variant {
cfg,
doc,
attrs,
name,
discriminant,
expr,
})
}
fn parse_foreign_mod(
cx: &mut Errors,
foreign_mod: ItemForeignMod,
out: &mut Vec<Api>,
trusted: bool,
namespace: &Namespace,
) {
let lang = match parse_lang(&foreign_mod.abi) {
Ok(lang) => lang,
Err(err) => return cx.push(err),
};
match lang {
Lang::Rust => {
if foreign_mod.unsafety.is_some() {
let unsafety = foreign_mod.unsafety;
let abi = &foreign_mod.abi;
let span = quote!(#unsafety #abi);
cx.error(span, "extern \"Rust\" block does not need to be unsafe");
}
}
Lang::Cxx => {}
}
let trusted = trusted || foreign_mod.unsafety.is_some();
let mut cfg = CfgExpr::Unconditional;
let mut namespace = namespace.clone();
let attrs = attrs::parse(
cx,
foreign_mod.attrs,
attrs::Parser {
cfg: Some(&mut cfg),
namespace: Some(&mut namespace),
..Default::default()
},
);
let mut items = Vec::new();
for foreign in foreign_mod.items {
match foreign {
ForeignItem::Type(foreign) => {
let ety = parse_extern_type(cx, foreign, lang, trusted, &cfg, &namespace, &attrs);
items.push(ety);
}
ForeignItem::Fn(foreign) => {
match parse_extern_fn(cx, foreign, lang, trusted, &cfg, &namespace, &attrs) {
Ok(efn) => items.push(efn),
Err(err) => cx.push(err),
}
}
ForeignItem::Macro(foreign) if foreign.mac.path.is_ident("include") => {
match foreign.mac.parse_body_with(parse_include) {
Ok(mut include) => {
include.cfg = cfg.clone();
items.push(Api::Include(include));
}
Err(err) => cx.push(err),
}
}
ForeignItem::Verbatim(tokens) => {
match parse_extern_verbatim(cx, tokens, lang, trusted, &cfg, &namespace, &attrs) {
Ok(api) => items.push(api),
Err(err) => cx.push(err),
}
}
_ => cx.error(foreign, "unsupported foreign item"),
}
}
if !trusted
&& items.iter().any(|api| match api {
Api::CxxFunction(efn) => efn.unsafety.is_none(),
_ => false,
})
{
cx.error(
foreign_mod.abi,
"block must be declared `unsafe extern \"C++\"` if it contains any safe-to-call C++ functions",
);
}
let mut types = items.iter().filter_map(|item| match item {
Api::CxxType(ety) | Api::RustType(ety) => Some(&ety.name),
Api::TypeAlias(alias) => Some(&alias.name),
_ => None,
});
if let (Some(single_type), None) = (types.next(), types.next()) {
let single_type = single_type.clone();
for item in &mut items {
if let Api::CxxFunction(efn) | Api::RustFunction(efn) = item {
if let Some(receiver) = &mut efn.receiver {
if receiver.ty.rust == "Self" {
receiver.ty.rust = single_type.rust.clone();
}
}
}
}
}
out.extend(items);
}
fn parse_lang(abi: &Abi) -> Result<Lang> {
let Some(name) = &abi.name else {
return Err(Error::new_spanned(
abi,
"ABI name is required, extern \"C++\" or extern \"Rust\"",
));
};
match name.value().as_str() {
"C++" => Ok(Lang::Cxx),
"Rust" => Ok(Lang::Rust),
_ => Err(Error::new_spanned(
abi,
"unrecognized ABI, requires either \"C++\" or \"Rust\"",
)),
}
}
fn parse_extern_type(
cx: &mut Errors,
foreign_type: ForeignItemType,
lang: Lang,
trusted: bool,
extern_block_cfg: &CfgExpr,
namespace: &Namespace,
attrs: &OtherAttrs,
) -> Api {
let mut cfg = extern_block_cfg.clone();
let mut doc = Doc::new();
let mut derives = Vec::new();
let mut namespace = namespace.clone();
let mut cxx_name = None;
let mut rust_name = None;
let mut attrs = attrs.clone();
attrs.extend(attrs::parse(
cx,
foreign_type.attrs,
attrs::Parser {
cfg: Some(&mut cfg),
doc: Some(&mut doc),
derives: Some(&mut derives),
namespace: Some(&mut namespace),
cxx_name: Some(&mut cxx_name),
rust_name: Some(&mut rust_name),
..Default::default()
},
));
let type_token = foreign_type.type_token;
let visibility = visibility_pub(&foreign_type.vis, type_token.span);
let name = pair(namespace, &foreign_type.ident, cxx_name, rust_name);
let generics = extern_type_lifetimes(cx, foreign_type.generics);
let colon_token = None;
let bounds = Vec::new();
let semi_token = foreign_type.semi_token;
(match lang {
Lang::Cxx => Api::CxxType,
Lang::Rust => Api::RustType,
})(ExternType {
cfg,
lang,
doc,
derives,
attrs,
visibility,
type_token,
name,
generics,
colon_token,
bounds,
semi_token,
trusted,
})
}
fn parse_extern_fn(
cx: &mut Errors,
mut foreign_fn: ForeignItemFn,
lang: Lang,
trusted: bool,
extern_block_cfg: &CfgExpr,
namespace: &Namespace,
attrs: &OtherAttrs,
) -> Result<Api> {
let mut cfg = extern_block_cfg.clone();
let mut doc = Doc::new();
let mut namespace = namespace.clone();
let mut cxx_name = None;
let mut rust_name = None;
let mut attrs = attrs.clone();
attrs.extend(attrs::parse(
cx,
mem::take(&mut foreign_fn.attrs),
attrs::Parser {
cfg: Some(&mut cfg),
doc: Some(&mut doc),
namespace: Some(&mut namespace),
cxx_name: Some(&mut cxx_name),
rust_name: Some(&mut rust_name),
..Default::default()
},
));
let generics = &foreign_fn.sig.generics;
if generics.where_clause.is_some()
|| generics.params.iter().any(|param| match param {
GenericParam::Lifetime(lifetime) => !lifetime.bounds.is_empty(),
GenericParam::Type(_) | GenericParam::Const(_) => true,
})
{
return Err(Error::new_spanned(
foreign_fn,
"extern function with generic parameters is not supported yet",
));
}
if let Some(variadic) = &foreign_fn.sig.variadic {
return Err(Error::new_spanned(
variadic,
"variadic function is not supported yet",
));
}
if foreign_fn.sig.asyncness.is_some() && !cfg!(feature = "experimental-async-fn") {
return Err(Error::new_spanned(
foreign_fn,
"async function is not directly supported yet, but see https://cxx.rs/async.html \
for a working approach, and https://github.com/pcwalton/cxx-async for some helpers; \
eventually what you wrote will work but it isn't integrated into the cxx::bridge \
macro yet",
));
}
if foreign_fn.sig.constness.is_some() {
return Err(Error::new_spanned(
foreign_fn,
"const extern function is not supported",
));
}
if let Some(abi) = &foreign_fn.sig.abi {
return Err(Error::new_spanned(
abi,
"explicit ABI on extern function is not supported",
));
}
let mut receiver = None;
let mut args = Punctuated::new();
for arg in foreign_fn.sig.inputs.pairs() {
let (arg, comma) = arg.into_tuple();
match arg {
FnArg::Receiver(arg) => {
if let Some((ampersand, lifetime)) = &arg.reference {
receiver = Some(Receiver {
pinned: false,
ampersand: *ampersand,
lifetime: lifetime.clone(),
mutable: arg.mutability.is_some(),
var: arg.self_token,
colon_token: Token,
ty: NamedType::new(Ident::new("Self", arg.self_token.span)),
shorthand: true,
pin_tokens: None,
mutability: arg.mutability,
});
continue;
}
if let Some(colon_token) = arg.colon_token {
let ty = parse_type(&arg.ty)?;
if let Type::Ref(reference) = ty {
if let Type::Ident(ident) = reference.inner {
receiver = Some(Receiver {
pinned: reference.pinned,
ampersand: reference.ampersand,
lifetime: reference.lifetime,
mutable: reference.mutable,
var: Token),
colon_token,
ty: ident,
shorthand: false,
pin_tokens: reference.pin_tokens,
mutability: reference.mutability,
});
continue;
}
}
}
return Err(Error::new_spanned(arg, "unsupported method receiver"));
}
FnArg::Typed(arg) => {
let ident = match arg.pat.as_ref() {
Pat::Ident(pat) => pat.ident.clone(),
Pat::Wild(pat) => {
Ident::new(&format!("arg{}", args.len()), pat.underscore_token.span)
}
_ => return Err(Error::new_spanned(arg, "unsupported signature")),
};
let ty = parse_type(&arg.ty)?;
let cfg = CfgExpr::Unconditional;
let doc = Doc::new();
let attrs = OtherAttrs::none();
let visibility = Token);
let name = pair(Namespace::default(), &ident, None, None);
let colon_token = arg.colon_token;
args.push_value(Var {
cfg,
doc,
attrs,
visibility,
name,
colon_token,
ty,
});
if let Some(comma) = comma {
args.push_punct(*comma);
}
}
}
}
let mut throws_tokens = None;
let ret = parse_return_type(&foreign_fn.sig.output, &mut throws_tokens)?;
let throws = throws_tokens.is_some();
let asyncness = foreign_fn.sig.asyncness;
let unsafety = foreign_fn.sig.unsafety;
let fn_token = foreign_fn.sig.fn_token;
let inherited_span = unsafety.map_or(fn_token.span, |unsafety| unsafety.span);
let visibility = visibility_pub(&foreign_fn.vis, inherited_span);
let name = pair(namespace, &foreign_fn.sig.ident, cxx_name, rust_name);
let generics = generics.clone();
let paren_token = foreign_fn.sig.paren_token;
let semi_token = foreign_fn.semi_token;
Ok(match lang {
Lang::Cxx => Api::CxxFunction,
Lang::Rust => Api::RustFunction,
}(ExternFn {
cfg,
lang,
doc,
attrs,
visibility,
name,
sig: Signature {
asyncness,
unsafety,
fn_token,
generics,
receiver,
args,
ret,
throws,
paren_token,
throws_tokens,
},
semi_token,
trusted,
}))
}
fn parse_extern_verbatim(
cx: &mut Errors,
tokens: TokenStream,
lang: Lang,
trusted: bool,
extern_block_cfg: &CfgExpr,
namespace: &Namespace,
attrs: &OtherAttrs,
) -> Result<Api> {
|input: ParseStream| -> Result<Api> {
let unparsed_attrs = input.call(Attribute::parse_outer)?;
let visibility: Visibility = input.parse()?;
if input.peek(Token![type]) {
parse_extern_verbatim_type(
cx,
unparsed_attrs,
visibility,
input,
lang,
trusted,
extern_block_cfg,
namespace,
attrs,
)
} else if input.peek(Token![fn]) {
parse_extern_verbatim_fn(input)
} else {
let span = input.cursor().token_stream();
Err(Error::new_spanned(
span,
"unsupported foreign item, expected `type` or `fn`",
))
}
}
.parse2(tokens)
}
fn parse_extern_verbatim_type(
cx: &mut Errors,
unparsed_attrs: Vec<Attribute>,
visibility: Visibility,
input: ParseStream,
lang: Lang,
trusted: bool,
extern_block_cfg: &CfgExpr,
namespace: &Namespace,
attrs: &OtherAttrs,
) -> Result<Api> {
let type_token: Token![type] = input.parse()?;
let ident: Ident = input.parse()?;
let generics: Generics = input.parse()?;
let lifetimes = extern_type_lifetimes(cx, generics);
let lookahead = input.lookahead1();
if lookahead.peek(Token![=]) {
// type Alias = crate::path::to::Type;
parse_type_alias(
cx,
unparsed_attrs,
visibility,
type_token,
ident,
lifetimes,
input,
lang,
extern_block_cfg,
namespace,
attrs,
)
} else if lookahead.peek(Token![:]) {
// type Opaque: Bound2 + Bound2;
parse_extern_type_bounded(
cx,
unparsed_attrs,
visibility,
type_token,
ident,
lifetimes,
input,
lang,
trusted,
extern_block_cfg,
namespace,
attrs,
)
} else {
Err(lookahead.error())
}
}
fn extern_type_lifetimes(cx: &mut Errors, generics: Generics) -> Lifetimes {
let mut lifetimes = Punctuated::new();
let mut has_unsupported_generic_param = false;
for pair in generics.params.into_pairs() {
let (param, punct) = pair.into_tuple();
match param {
GenericParam::Lifetime(param) => {
if !param.bounds.is_empty() && !has_unsupported_generic_param {
let msg = "lifetime parameter with bounds is not supported yet";
cx.error(¶m, msg);
has_unsupported_generic_param = true;
}
lifetimes.push_value(param.lifetime);
if let Some(punct) = punct {
lifetimes.push_punct(punct);
}
}
GenericParam::Type(param) => {
if !has_unsupported_generic_param {
let msg = "extern type with generic type parameter is not supported yet";
cx.error(¶m, msg);
has_unsupported_generic_param = true;
}
}
GenericParam::Const(param) => {
if !has_unsupported_generic_param {
let msg = "extern type with const generic parameter is not supported yet";
cx.error(¶m, msg);
has_unsupported_generic_param = true;
}
}
}
}
Lifetimes {
lt_token: generics.lt_token,
lifetimes,
gt_token: generics.gt_token,
}
}
fn parse_extern_verbatim_fn(input: ParseStream) -> Result<Api> {
input.parse::<RustSignature>()?;
input.parse::<Token![;]>()?;
unreachable!()
}
fn parse_type_alias(
cx: &mut Errors,
unparsed_attrs: Vec<Attribute>,
visibility: Visibility,
type_token: Token![type],
ident: Ident,
generics: Lifetimes,
input: ParseStream,
lang: Lang,
extern_block_cfg: &CfgExpr,
namespace: &Namespace,
attrs: &OtherAttrs,
) -> Result<Api> {
let eq_token: Token![=] = input.parse()?;
let ty: RustType = input.parse()?;
let semi_token: Token![;] = input.parse()?;
let mut cfg = extern_block_cfg.clone();
let mut doc = Doc::new();
let mut derives = Vec::new();
let mut namespace = namespace.clone();
let mut cxx_name = None;
let mut rust_name = None;
let mut attrs = attrs.clone();
attrs.extend(attrs::parse(
cx,
unparsed_attrs,
attrs::Parser {
cfg: Some(&mut cfg),
doc: Some(&mut doc),
derives: Some(&mut derives),
namespace: Some(&mut namespace),
cxx_name: Some(&mut cxx_name),
rust_name: Some(&mut rust_name),
..Default::default()
},
));
if lang == Lang::Rust {
let span = quote!(#type_token #semi_token);
let msg = "type alias in extern \"Rust\" block is not supported";
return Err(Error::new_spanned(span, msg));
}
let visibility = visibility_pub(&visibility, type_token.span);
let name = pair(namespace, &ident, cxx_name, rust_name);
Ok(Api::TypeAlias(TypeAlias {
cfg,
doc,
derives,
attrs,
visibility,
type_token,
name,
generics,
eq_token,
ty,
semi_token,
}))
}
fn parse_extern_type_bounded(
cx: &mut Errors,
unparsed_attrs: Vec<Attribute>,
visibility: Visibility,
type_token: Token![type],
ident: Ident,
generics: Lifetimes,
input: ParseStream,
lang: Lang,
trusted: bool,
extern_block_cfg: &CfgExpr,
namespace: &Namespace,
attrs: &OtherAttrs,
) -> Result<Api> {
let mut bounds = Vec::new();
let colon_token: Option<Token![:]> = input.parse()?;
if colon_token.is_some() {
loop {
match input.parse()? {
TypeParamBound::Trait(TraitBound {
paren_token: None,
modifier: TraitBoundModifier::None,
lifetimes: None,
path,
}) if if let Some(derive) = path.get_ident().and_then(Derive::from) {
bounds.push(derive);
true
} else {
false
} => {}
bound => cx.error(bound, "unsupported trait"),
}
let lookahead = input.lookahead1();
if lookahead.peek(Token![+]) {
input.parse::<Token![+]>()?;
} else if lookahead.peek(Token![;]) {
break;
} else {
return Err(lookahead.error());
}
}
}
let semi_token: Token![;] = input.parse()?;
let mut cfg = extern_block_cfg.clone();
let mut doc = Doc::new();
let mut derives = Vec::new();
let mut namespace = namespace.clone();
let mut cxx_name = None;
let mut rust_name = None;
let mut attrs = attrs.clone();
attrs.extend(attrs::parse(
cx,
unparsed_attrs,
attrs::Parser {
cfg: Some(&mut cfg),
doc: Some(&mut doc),
derives: Some(&mut derives),
namespace: Some(&mut namespace),
cxx_name: Some(&mut cxx_name),
rust_name: Some(&mut rust_name),
..Default::default()
},
));
let visibility = visibility_pub(&visibility, type_token.span);
let name = pair(namespace, &ident, cxx_name, rust_name);
Ok(match lang {
Lang::Cxx => Api::CxxType,
Lang::Rust => Api::RustType,
}(ExternType {
cfg,
lang,
doc,
derives,
attrs,
visibility,
type_token,
name,
generics,
colon_token,
bounds,
semi_token,
trusted,
}))
}
fn parse_impl(cx: &mut Errors, imp: ItemImpl) -> Result<Api> {
let impl_token = imp.impl_token;
let mut cfg = CfgExpr::Unconditional;
attrs::parse(
cx,
imp.attrs,
attrs::Parser {
cfg: Some(&mut cfg),
..Default::default()
},
);
if !imp.items.is_empty() {
let mut span = Group::new(Delimiter::Brace, TokenStream::new());
span.set_span(imp.brace_token.span.join());
return Err(Error::new_spanned(span, "expected an empty impl block"));
}
if let Some((bang, path, for_token)) = &imp.trait_ {
let self_ty = &imp.self_ty;
let span = quote!(#bang #path #for_token #self_ty);
return Err(Error::new_spanned(
span,
"unexpected impl, expected something like `impl UniquePtr<T> {}`",
));
}
if let Some(where_clause) = imp.generics.where_clause {
return Err(Error::new_spanned(
where_clause,
"where-clause on an impl is not supported yet",
));
}
let mut impl_generics = Lifetimes {
lt_token: imp.generics.lt_token,
lifetimes: Punctuated::new(),
gt_token: imp.generics.gt_token,
};
for pair in imp.generics.params.into_pairs() {
let (param, punct) = pair.into_tuple();
match param {
GenericParam::Lifetime(def) if def.bounds.is_empty() => {
impl_generics.lifetimes.push_value(def.lifetime);
if let Some(punct) = punct {
impl_generics.lifetimes.push_punct(punct);
}
}
_ => {
let span = quote!(#impl_token #impl_generics);
return Err(Error::new_spanned(
span,
"generic parameter on an impl is not supported yet",
));
}
}
}
let mut negative_token = None;
let mut self_ty = *imp.self_ty;
if let RustType::Verbatim(ty) = &self_ty {
let mut iter = ty.clone().into_iter();
if let Some(TokenTree::Punct(punct)) = iter.next() {
if punct.as_char() == '!' {
let ty = iter.collect::<TokenStream>();
if !ty.is_empty() {
negative_token = Some(Token));
self_ty = syn::parse2(ty)?;
}
}
}
}
let ty = parse_type(&self_ty)?;
let ty_generics = match &ty {
Type::RustBox(ty)
| Type::RustVec(ty)
| Type::UniquePtr(ty)
| Type::SharedPtr(ty)
| Type::WeakPtr(ty)
| Type::CxxVector(ty) => match &ty.inner {
Type::Ident(ident) => ident.generics.clone(),
_ => Lifetimes::default(),
},
Type::Ident(_)
| Type::Ref(_)
| Type::Ptr(_)
| Type::Str(_)
| Type::Fn(_)
| Type::Void(_)
| Type::SliceRef(_)
| Type::Array(_) => Lifetimes::default(),
};
let negative = negative_token.is_some();
let brace_token = imp.brace_token;
Ok(Api::Impl(Impl {
cfg,
impl_token,
impl_generics,
negative,
ty,
ty_generics,
brace_token,
negative_token,
}))
}
fn parse_include(input: ParseStream) -> Result<Include> {
if input.peek(LitStr) {
let lit: LitStr = input.parse()?;
let span = lit.span();
return Ok(Include {
cfg: CfgExpr::Unconditional,
path: lit.value(),
kind: IncludeKind::Quoted,
begin_span: span,
end_span: span,
});
}
if input.peek(Token![<]) {
let mut path = String::new();
let langle: Token![<] = input.parse()?;
while !input.is_empty() && !input.peek(Token![>]) {
let token: TokenTree = input.parse()?;
match token {
TokenTree::Ident(token) => path += &token.to_string(),
TokenTree::Literal(token)
if token
.to_string()
.starts_with(|ch: char| ch.is_ascii_digit()) =>
{
path += &token.to_string();
}
TokenTree::Punct(token) => path.push(token.as_char()),
_ => return Err(Error::new(token.span(), "unexpected token in include path")),
}
}
let rangle: Token![>] = input.parse()?;
return Ok(Include {
cfg: CfgExpr::Unconditional,
path,
kind: IncludeKind::Bracketed,
begin_span: langle.span,
end_span: rangle.span,
});
}
Err(input.error("expected \"quoted/path/to\" or <bracketed/path/to>"))
}
fn parse_type(ty: &RustType) -> Result<Type> {
match ty {
RustType::Reference(ty) => parse_type_reference(ty),
RustType::Ptr(ty) => parse_type_ptr(ty),
RustType::Path(ty) => parse_type_path(ty),
RustType::Array(ty) => parse_type_array(ty),
RustType::BareFn(ty) => parse_type_fn(ty),
RustType::Tuple(ty) if ty.elems.is_empty() => Ok(Type::Void(ty.paren_token.span.join())),
_ => Err(Error::new_spanned(ty, "unsupported type")),
}
}
fn parse_type_reference(ty: &TypeReference) -> Result<Type> {
let ampersand = ty.and_token;
let lifetime = ty.lifetime.clone();
let mutable = ty.mutability.is_some();
let mutability = ty.mutability;
if let RustType::Slice(slice) = ty.elem.as_ref() {
let inner = parse_type(&slice.elem)?;
let bracket = slice.bracket_token;
return Ok(Type::SliceRef(Box::new(SliceRef {
ampersand,
lifetime,
mutable,
bracket,
inner,
mutability,
})));
}
let inner = parse_type(&ty.elem)?;
let pinned = false;
let pin_tokens = None;
Ok(match &inner {
Type::Ident(ident) if ident.rust == "str" => {
if ty.mutability.is_some() {
return Err(Error::new_spanned(ty, "unsupported type"));
} else {
Type::Str
}
}
_ => Type::Ref,
}(Box::new(Ref {
pinned,
ampersand,
lifetime,
mutable,
inner,
pin_tokens,
mutability,
})))
}
fn parse_type_ptr(ty: &TypePtr) -> Result<Type> {
let star = ty.star_token;
let mutable = ty.mutability.is_some();
let constness = ty.const_token;
let mutability = ty.mutability;
let inner = parse_type(&ty.elem)?;
Ok(Type::Ptr(Box::new(Ptr {
star,
mutable,
inner,
mutability,
constness,
})))
}
fn parse_type_path(ty: &TypePath) -> Result<Type> {
let path = &ty.path;
if ty.qself.is_none() && path.leading_colon.is_none() && path.segments.len() == 1 {
let segment = &path.segments[0];
let ident = segment.ident.clone();
match &segment.arguments {
PathArguments::None => return Ok(Type::Ident(NamedType::new(ident))),
PathArguments::AngleBracketed(generic) => {
if ident == "UniquePtr" && generic.args.len() == 1 {
if let GenericArgument::Type(arg) = &generic.args[0] {
let inner = parse_type(arg)?;
return Ok(Type::UniquePtr(Box::new(Ty1 {
name: ident,
langle: generic.lt_token,
inner,
rangle: generic.gt_token,
})));
}
} else if ident == "SharedPtr" && generic.args.len() == 1 {
if let GenericArgument::Type(arg) = &generic.args[0] {
let inner = parse_type(arg)?;
return Ok(Type::SharedPtr(Box::new(Ty1 {
name: ident,
langle: generic.lt_token,
inner,
rangle: generic.gt_token,
})));
}
} else if ident == "WeakPtr" && generic.args.len() == 1 {
if let GenericArgument::Type(arg) = &generic.args[0] {
let inner = parse_type(arg)?;
return Ok(Type::WeakPtr(Box::new(Ty1 {
name: ident,
langle: generic.lt_token,
inner,
rangle: generic.gt_token,
})));
}
} else if ident == "CxxVector" && generic.args.len() == 1 {
if let GenericArgument::Type(arg) = &generic.args[0] {
let inner = parse_type(arg)?;
return Ok(Type::CxxVector(Box::new(Ty1 {
name: ident,
langle: generic.lt_token,
inner,
rangle: generic.gt_token,
})));
}
} else if ident == "Box" && generic.args.len() == 1 {
if let GenericArgument::Type(arg) = &generic.args[0] {
let inner = parse_type(arg)?;
return Ok(Type::RustBox(Box::new(Ty1 {
name: ident,
langle: generic.lt_token,
inner,
rangle: generic.gt_token,
})));
}
} else if ident == "Vec" && generic.args.len() == 1 {
if let GenericArgument::Type(arg) = &generic.args[0] {
let inner = parse_type(arg)?;
return Ok(Type::RustVec(Box::new(Ty1 {
name: ident,
langle: generic.lt_token,
inner,
rangle: generic.gt_token,
})));
}
} else if ident == "Pin" && generic.args.len() == 1 {
if let GenericArgument::Type(arg) = &generic.args[0] {
let inner = parse_type(arg)?;
let pin_token = kw::Pin(ident.span());
if let Type::Ref(mut inner) = inner {
inner.pinned = true;
inner.pin_tokens =
Some((pin_token, generic.lt_token, generic.gt_token));
return Ok(Type::Ref(inner));
}
}
} else {
let mut lifetimes = Punctuated::new();
let mut only_lifetimes = true;
for pair in generic.args.pairs() {
let (param, punct) = pair.into_tuple();
if let GenericArgument::Lifetime(param) = param {
lifetimes.push_value(param.clone());
if let Some(punct) = punct {
lifetimes.push_punct(*punct);
}
} else {
only_lifetimes = false;
break;
}
}
if only_lifetimes {
return Ok(Type::Ident(NamedType {
rust: ident,
generics: Lifetimes {
lt_token: Some(generic.lt_token),
lifetimes,
gt_token: Some(generic.gt_token),
},
}));
}
}
}
PathArguments::Parenthesized(_) => {}
}
}
Err(Error::new_spanned(ty, "unsupported type"))
}
fn parse_type_array(ty: &TypeArray) -> Result<Type> {
let inner = parse_type(&ty.elem)?;
let Expr::Lit(len_expr) = &ty.len else {
let msg = "unsupported expression, array length must be an integer literal";
return Err(Error::new_spanned(&ty.len, msg));
};
let Lit::Int(len_token) = &len_expr.lit else {
let msg = "array length must be an integer literal";
return Err(Error::new_spanned(len_expr, msg));
};
let len = len_token.base10_parse::<usize>()?;
if len == 0 {
let msg = "array with zero size is not supported";
return Err(Error::new_spanned(ty, msg));
}
let bracket = ty.bracket_token;
let semi_token = ty.semi_token;
Ok(Type::Array(Box::new(Array {
bracket,
inner,
semi_token,
len,
len_token: len_token.clone(),
})))
}
fn parse_type_fn(ty: &TypeBareFn) -> Result<Type> {
if ty.lifetimes.is_some() {
return Err(Error::new_spanned(
ty,
"function pointer with lifetime parameters is not supported yet",
));
}
if ty.variadic.is_some() {
return Err(Error::new_spanned(
ty,
"variadic function pointer is not supported yet",
));
}
let args = ty
.inputs
.iter()
.enumerate()
.map(|(i, arg)| {
let (ident, colon_token) = match &arg.name {
Some((ident, colon_token)) => (ident.clone(), *colon_token),
None => {
let fn_span = ty.paren_token.span.join();
let ident = format_ident!("arg{}", i, span = fn_span);
let colon_token = Token;
(ident, colon_token)
}
};
let ty = parse_type(&arg.ty)?;
let cfg = CfgExpr::Unconditional;
let doc = Doc::new();
let attrs = OtherAttrs::none();
let visibility = Token);
let name = pair(Namespace::default(), &ident, None, None);
Ok(Var {
cfg,
doc,
attrs,
visibility,
name,
colon_token,
ty,
})
})
.collect::<Result<_>>()?;
let mut throws_tokens = None;
let ret = parse_return_type(&ty.output, &mut throws_tokens)?;
let throws = throws_tokens.is_some();
let asyncness = None;
let unsafety = ty.unsafety;
let fn_token = ty.fn_token;
let generics = Generics::default();
let receiver = None;
let paren_token = ty.paren_token;
Ok(Type::Fn(Box::new(Signature {
asyncness,
unsafety,
fn_token,
generics,
receiver,
args,
ret,
throws,
paren_token,
throws_tokens,
})))
}
fn parse_return_type(
ty: &ReturnType,
throws_tokens: &mut Option<(kw::Result, Token![<], Token![>])>,
) -> Result<Option<Type>> {
let mut ret = match ty {
ReturnType::Default => return Ok(None),
ReturnType::Type(_, ret) => ret.as_ref(),
};
if let RustType::Path(ty) = ret {
let path = &ty.path;
if ty.qself.is_none() && path.leading_colon.is_none() && path.segments.len() == 1 {
let segment = &path.segments[0];
let ident = segment.ident.clone();
if let PathArguments::AngleBracketed(generic) = &segment.arguments {
if ident == "Result" && generic.args.len() == 1 {
if let GenericArgument::Type(arg) = &generic.args[0] {
ret = arg;
*throws_tokens =
Some((kw::Result(ident.span()), generic.lt_token, generic.gt_token));
}
}
}
}
}
match parse_type(ret)? {
Type::Void(_) => Ok(None),
ty => Ok(Some(ty)),
}
}
fn visibility_pub(vis: &Visibility, inherited: Span) -> Token![pub] {
Token => vis.span,
Visibility::Restricted(vis) => vis.pub_token.span,
Visibility::Inherited => inherited,
})
}
fn pair(
namespace: Namespace,
default: &Ident,
cxx: Option<ForeignName>,
rust: Option<Ident>,
) -> Pair {
Pair {
namespace,
cxx: cxx
.unwrap_or_else(|| ForeignName::parse(&default.to_string(), default.span()).unwrap()),
rust: rust.unwrap_or_else(|| default.clone()),
}
}
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