bjoernager/rust
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add auto keyword, parse auto trait, lower to HIR

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Adds an `IsAuto` field to `ItemTrait` which flags if the trait was
declared as an `auto trait`.

Auto traits cannot have generics nor super traits.
This commit is contained in:
leonardo.yvens 2017-10-12 09:51:31 -03:00
parent 06506bb751
commit 1f4b630899
17 changed files with 122 additions and 31 deletions
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46
src/libsyntax/parse/parser.rs
View file

@ -16,12 +16,13 @@ use ast::{Mod, Arg, Arm, Attribute, BindingMode, TraitItemKind};
use ast::Block;
use ast::{BlockCheckMode, CaptureBy};
use ast::{Constness, Crate};
use ast::Generics;
use ast::Defaultness;
use ast::EnumDef;
use ast::{Expr, ExprKind, RangeLimits};
use ast::{Field, FnDecl};
use ast::{ForeignItem, ForeignItemKind, FunctionRetTy};
use ast::{Ident, ImplItem, Item, ItemKind};
use ast::{Ident, ImplItem, IsAuto, Item, ItemKind};
use ast::{Lifetime, LifetimeDef, Lit, LitKind, UintTy};
use ast::Local;
use ast::MacStmtStyle;
@ -5078,7 +5079,17 @@ impl<'a> Parser<'a> {
}
}
}
Ok((ident, ItemKind::Trait(unsafety, tps, bounds, trait_items), None))
Ok((ident, ItemKind::Trait(IsAuto::No, unsafety, tps, bounds, trait_items), None))
}
fn parse_item_auto_trait(&mut self, unsafety: Unsafety) -> PResult<'a, ItemInfo> {
let ident = self.parse_ident()?;
self.expect(&token::OpenDelim(token::Brace))?;
self.expect(&token::CloseDelim(token::Brace))?;
// Auto traits cannot have generics, super traits nor contain items.
Ok((ident,
ItemKind::Trait(IsAuto::Yes, unsafety, Generics::default(), Vec::new(), Vec::new()),
None))
}
/// Parses items implementations variants
@ -6127,6 +6138,37 @@ impl<'a> Parser<'a> {
maybe_append(attrs, extra_attrs));
return Ok(Some(item));
}
if self.eat_keyword(keywords::Auto) {
self.expect_keyword(keywords::Trait)?;
// AUTO TRAIT ITEM
let (ident,
item_,
extra_attrs) = self.parse_item_auto_trait(ast::Unsafety::Normal)?;
let prev_span = self.prev_span;
let item = self.mk_item(lo.to(prev_span),
ident,
item_,
visibility,
maybe_append(attrs, extra_attrs));
return Ok(Some(item));
}
if self.check_keyword(keywords::Unsafe) &&
self.look_ahead(1, |t| t.is_keyword(keywords::Auto)) {
self.expect_keyword(keywords::Unsafe)?;
self.expect_keyword(keywords::Auto)?;
self.expect_keyword(keywords::Trait)?;
// UNSAFE AUTO TRAIT ITEM
let (ident,
item_,
extra_attrs) = self.parse_item_auto_trait(ast::Unsafety::Unsafe)?;
let prev_span = self.prev_span;
let item = self.mk_item(lo.to(prev_span),
ident,
item_,
visibility,
maybe_append(attrs, extra_attrs));
return Ok(Some(item));
}
if self.eat_keyword(keywords::Struct) {
// STRUCT ITEM
let (ident, item_, extra_attrs) = self.parse_item_struct()?;