diff options
Diffstat (limited to 'src/libsyntax/parse/parser.rs')
| -rw-r--r-- | src/libsyntax/parse/parser.rs | 87 |
1 files changed, 64 insertions, 23 deletions
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs index 2b6f91bbc99..eb6420165da 100644 --- a/src/libsyntax/parse/parser.rs +++ b/src/libsyntax/parse/parser.rs @@ -17,7 +17,7 @@ use ast::{Public, Unsafety}; use ast::{Mod, BiAdd, Arg, Arm, Attribute, BindByRef, BindByValue}; use ast::{BiBitAnd, BiBitOr, BiBitXor, BiRem, BiLt, BiGt, Block}; use ast::{BlockCheckMode, CaptureByRef, CaptureByValue, CaptureClause}; -use ast::{ConstImplItem, ConstTraitItem, Crate, CrateConfig}; +use ast::{Constness, ConstImplItem, ConstTraitItem, Crate, CrateConfig}; use ast::{Decl, DeclItem, DeclLocal, DefaultBlock, DefaultReturn}; use ast::{UnDeref, BiDiv, EMPTY_CTXT, EnumDef, ExplicitSelf}; use ast::{Expr, Expr_, ExprAddrOf, ExprMatch, ExprAgain}; @@ -1160,7 +1160,8 @@ impl<'a> Parser<'a> { let TyParam {ident, bounds, default, ..} = try!(p.parse_ty_param()); try!(p.expect(&token::Semi)); (ident, TypeTraitItem(bounds, default)) - } else if try!(p.eat_keyword(keywords::Const)) { + } else if p.is_const_item() { + try!(p.expect_keyword(keywords::Const)); let ident = try!(p.parse_ident()); try!(p.expect(&token::Colon)); let ty = try!(p.parse_ty_sum()); @@ -1175,13 +1176,7 @@ impl<'a> Parser<'a> { }; (ident, ConstTraitItem(ty, default)) } else { - let style = try!(p.parse_unsafety()); - let abi = if try!(p.eat_keyword(keywords::Extern)) { - try!(p.parse_opt_abi()).unwrap_or(abi::C) - } else { - abi::Rust - }; - try!(p.expect_keyword(keywords::Fn)); + let (constness, unsafety, abi) = try!(p.parse_fn_front_matter()); let ident = try!(p.parse_ident()); let mut generics = try!(p.parse_generics()); @@ -1195,7 +1190,8 @@ impl<'a> Parser<'a> { generics.where_clause = try!(p.parse_where_clause()); let sig = ast::MethodSig { - unsafety: style, + unsafety: unsafety, + constness: constness, decl: d, generics: generics, abi: abi, @@ -4359,12 +4355,46 @@ impl<'a> Parser<'a> { } /// Parse an item-position function declaration. - fn parse_item_fn(&mut self, unsafety: Unsafety, abi: abi::Abi) -> PResult<ItemInfo> { + fn parse_item_fn(&mut self, + unsafety: Unsafety, + constness: Constness, + abi: abi::Abi) + -> PResult<ItemInfo> { let (ident, mut generics) = try!(self.parse_fn_header()); let decl = try!(self.parse_fn_decl(false)); generics.where_clause = try!(self.parse_where_clause()); let (inner_attrs, body) = try!(self.parse_inner_attrs_and_block()); - Ok((ident, ItemFn(decl, unsafety, abi, generics, body), Some(inner_attrs))) + Ok((ident, ItemFn(decl, unsafety, constness, abi, generics, body), Some(inner_attrs))) + } + + /// true if we are looking at `const ID`, false for things like `const fn` etc + pub fn is_const_item(&mut self) -> bool { + self.token.is_keyword(keywords::Const) && + !self.look_ahead(1, |t| t.is_keyword(keywords::Fn)) + } + + /// parses all the "front matter" for a `fn` declaration, up to + /// and including the `fn` keyword: + /// + /// - `const fn` + /// - `unsafe fn` + /// - `extern fn` + /// - etc + pub fn parse_fn_front_matter(&mut self) -> PResult<(ast::Constness, ast::Unsafety, abi::Abi)> { + let is_const_fn = try!(self.eat_keyword(keywords::Const)); + let (constness, unsafety, abi) = if is_const_fn { + (Constness::Const, Unsafety::Normal, abi::Rust) + } else { + let unsafety = try!(self.parse_unsafety()); + let abi = if try!(self.eat_keyword(keywords::Extern)) { + try!(self.parse_opt_abi()).unwrap_or(abi::C) + } else { + abi::Rust + }; + (Constness::NotConst, unsafety, abi) + }; + try!(self.expect_keyword(keywords::Fn)); + Ok((constness, unsafety, abi)) } /// Parse an impl item. @@ -4380,7 +4410,8 @@ impl<'a> Parser<'a> { let typ = try!(self.parse_ty_sum()); try!(self.expect(&token::Semi)); (name, TypeImplItem(typ)) - } else if try!(self.eat_keyword(keywords::Const)) { + } else if self.is_const_item() { + try!(self.expect_keyword(keywords::Const)); let name = try!(self.parse_ident()); try!(self.expect(&token::Colon)); let typ = try!(self.parse_ty_sum()); @@ -4445,13 +4476,7 @@ impl<'a> Parser<'a> { } Ok((token::special_idents::invalid, vec![], ast::MacImplItem(m))) } else { - let unsafety = try!(self.parse_unsafety()); - let abi = if try!(self.eat_keyword(keywords::Extern)) { - try!(self.parse_opt_abi()).unwrap_or(abi::C) - } else { - abi::Rust - }; - try!(self.expect_keyword(keywords::Fn)); + let (constness, unsafety, abi) = try!(self.parse_fn_front_matter()); let ident = try!(self.parse_ident()); let mut generics = try!(self.parse_generics()); let (explicit_self, decl) = try!(self.parse_fn_decl_with_self(|p| { @@ -4464,6 +4489,7 @@ impl<'a> Parser<'a> { abi: abi, explicit_self: explicit_self, unsafety: unsafety, + constness: constness, decl: decl }, body))) } @@ -5252,7 +5278,7 @@ impl<'a> Parser<'a> { // EXTERN FUNCTION ITEM let abi = opt_abi.unwrap_or(abi::C); let (ident, item_, extra_attrs) = - try!(self.parse_item_fn(Unsafety::Normal, abi)); + try!(self.parse_item_fn(Unsafety::Normal, Constness::NotConst, abi)); let last_span = self.last_span; let item = self.mk_item(lo, last_span.hi, @@ -5287,6 +5313,21 @@ impl<'a> Parser<'a> { return Ok(Some(item)); } if try!(self.eat_keyword(keywords::Const) ){ + if self.check_keyword(keywords::Fn) { + // CONST FUNCTION ITEM + try!(self.bump()); + let (ident, item_, extra_attrs) = + try!(self.parse_item_fn(Unsafety::Normal, Constness::Const, abi::Rust)); + let last_span = self.last_span; + let item = self.mk_item(lo, + last_span.hi, + ident, + item_, + visibility, + maybe_append(attrs, extra_attrs)); + return Ok(Some(item)); + } + // CONST ITEM if try!(self.eat_keyword(keywords::Mut) ){ let last_span = self.last_span; @@ -5340,7 +5381,7 @@ impl<'a> Parser<'a> { // FUNCTION ITEM try!(self.bump()); let (ident, item_, extra_attrs) = - try!(self.parse_item_fn(Unsafety::Normal, abi::Rust)); + try!(self.parse_item_fn(Unsafety::Normal, Constness::NotConst, abi::Rust)); let last_span = self.last_span; let item = self.mk_item(lo, last_span.hi, @@ -5361,7 +5402,7 @@ impl<'a> Parser<'a> { }; try!(self.expect_keyword(keywords::Fn)); let (ident, item_, extra_attrs) = - try!(self.parse_item_fn(Unsafety::Unsafe, abi)); + try!(self.parse_item_fn(Unsafety::Unsafe, Constness::NotConst, abi)); let last_span = self.last_span; let item = self.mk_item(lo, last_span.hi, |