diff options
Diffstat (limited to 'src/libsyntax/parse/parser.rs')
| -rw-r--r-- | src/libsyntax/parse/parser.rs | 166 |
1 files changed, 109 insertions, 57 deletions
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs index 6264b7f3ed3..d1a683b0bd5 100644 --- a/src/libsyntax/parse/parser.rs +++ b/src/libsyntax/parse/parser.rs @@ -40,7 +40,7 @@ use ast::{Visibility, WhereClause}; use ast::{BinOpKind, UnOp}; use {ast, attr}; use codemap::{self, CodeMap, Spanned, spanned, respan}; -use syntax_pos::{self, Span, BytePos, mk_sp}; +use syntax_pos::{self, Span, Pos, BytePos, mk_sp}; use errors::{self, DiagnosticBuilder}; use ext::tt::macro_parser; use parse; @@ -685,7 +685,7 @@ impl<'a> Parser<'a> { pub fn parse_seq_to_before_gt_or_return<T, F>(&mut self, sep: Option<token::Token>, mut f: F) - -> PResult<'a, (P<[T]>, bool)> + -> PResult<'a, (Vec<T>, bool)> where F: FnMut(&mut Parser<'a>) -> PResult<'a, Option<T>>, { let mut v = Vec::new(); @@ -706,7 +706,7 @@ impl<'a> Parser<'a> { if i % 2 == 0 { match f(self)? { Some(result) => v.push(result), - None => return Ok((P::from_vec(v), true)) + None => return Ok((v, true)) } } else { if let Some(t) = sep.as_ref() { @@ -715,7 +715,7 @@ impl<'a> Parser<'a> { } } - return Ok((P::from_vec(v), false)); + return Ok((v, false)); } /// Parse a sequence bracketed by '<' and '>', stopping @@ -723,7 +723,7 @@ impl<'a> Parser<'a> { pub fn parse_seq_to_before_gt<T, F>(&mut self, sep: Option<token::Token>, mut f: F) - -> PResult<'a, P<[T]>> where + -> PResult<'a, Vec<T>> where F: FnMut(&mut Parser<'a>) -> PResult<'a, T>, { let (result, returned) = self.parse_seq_to_before_gt_or_return(sep, @@ -735,7 +735,7 @@ impl<'a> Parser<'a> { pub fn parse_seq_to_gt<T, F>(&mut self, sep: Option<token::Token>, f: F) - -> PResult<'a, P<[T]>> where + -> PResult<'a, Vec<T>> where F: FnMut(&mut Parser<'a>) -> PResult<'a, T>, { let v = self.parse_seq_to_before_gt(sep, f)?; @@ -746,7 +746,7 @@ impl<'a> Parser<'a> { pub fn parse_seq_to_gt_or_return<T, F>(&mut self, sep: Option<token::Token>, f: F) - -> PResult<'a, (P<[T]>, bool)> where + -> PResult<'a, (Vec<T>, bool)> where F: FnMut(&mut Parser<'a>) -> PResult<'a, Option<T>>, { let (v, returned) = self.parse_seq_to_before_gt_or_return(sep, f)?; @@ -1039,13 +1039,13 @@ impl<'a> Parser<'a> { let other_bounds = if self.eat(&token::BinOp(token::Plus)) { self.parse_ty_param_bounds()? } else { - P::new() + Vec::new() }; let all_bounds = Some(TraitTyParamBound(poly_trait_ref, TraitBoundModifier::None)).into_iter() - .chain(other_bounds.into_vec()) + .chain(other_bounds) .collect(); - Ok(ast::TyKind::PolyTraitRef(all_bounds)) + Ok(ast::TyKind::TraitObject(all_bounds)) } } @@ -1128,7 +1128,7 @@ impl<'a> Parser<'a> { self.expect_keyword(keywords::Const)?; let ident = self.parse_ident()?; self.expect(&token::Colon)?; - let ty = self.parse_ty_sum()?; + let ty = self.parse_ty()?; let default = if self.check(&token::Eq) { self.bump(); let expr = self.parse_expr()?; @@ -1244,30 +1244,30 @@ impl<'a> Parser<'a> { /// Parse a possibly mutable type pub fn parse_mt(&mut self) -> PResult<'a, MutTy> { let mutbl = self.parse_mutability()?; - let t = self.parse_ty()?; + let t = self.parse_ty_no_plus()?; Ok(MutTy { ty: t, mutbl: mutbl }) } /// Parse optional return type [ -> TY ] in function decl pub fn parse_ret_ty(&mut self) -> PResult<'a, FunctionRetTy> { if self.eat(&token::RArrow) { - Ok(FunctionRetTy::Ty(self.parse_ty()?)) + Ok(FunctionRetTy::Ty(self.parse_ty_no_plus()?)) } else { let pos = self.span.lo; Ok(FunctionRetTy::Default(mk_sp(pos, pos))) } } - /// Parse a type in a context where `T1+T2` is allowed. - pub fn parse_ty_sum(&mut self) -> PResult<'a, P<Ty>> { + /// Parse a type. + pub fn parse_ty(&mut self) -> PResult<'a, P<Ty>> { let lo = self.span.lo; - let lhs = self.parse_ty()?; + let lhs = self.parse_ty_no_plus()?; if !self.eat(&token::BinOp(token::Plus)) { return Ok(lhs); } - let bounds = self.parse_ty_param_bounds()?; + let mut bounds = self.parse_ty_param_bounds()?; // In type grammar, `+` is treated like a binary operator, // and hence both L and R side are required. @@ -1277,14 +1277,66 @@ impl<'a> Parser<'a> { "at least one type parameter bound \ must be specified"); } + if let TyKind::Path(None, ref path) = lhs.node { + let poly_trait_ref = PolyTraitRef { + bound_lifetimes: Vec::new(), + trait_ref: TraitRef { path: path.clone(), ref_id: lhs.id }, + span: lhs.span, + }; + let poly_trait_ref = TraitTyParamBound(poly_trait_ref, TraitBoundModifier::None); + bounds.insert(0, poly_trait_ref); + } else { + let mut err = struct_span_err!(self.sess.span_diagnostic, lhs.span, E0178, + "expected a path on the left-hand side \ + of `+`, not `{}`", + pprust::ty_to_string(&lhs)); + err.span_label(lhs.span, &format!("expected a path")); + let hi = bounds.iter().map(|x| match *x { + ast::TraitTyParamBound(ref tr, _) => tr.span.hi, + ast::RegionTyParamBound(ref r) => r.span.hi, + }).max_by_key(|x| x.to_usize()); + let full_span = hi.map(|hi| Span { + lo: lhs.span.lo, + hi: hi, + expn_id: lhs.span.expn_id, + }); + match (&lhs.node, full_span) { + (&TyKind::Rptr(ref lifetime, ref mut_ty), Some(full_span)) => { + let ty_str = pprust::to_string(|s| { + use print::pp::word; + use print::pprust::PrintState; + + word(&mut s.s, "&")?; + s.print_opt_lifetime(lifetime)?; + s.print_mutability(mut_ty.mutbl)?; + s.popen()?; + s.print_type(&mut_ty.ty)?; + s.print_bounds(" +", &bounds)?; + s.pclose() + }); + err.span_suggestion(full_span, "try adding parentheses (per RFC 438):", + ty_str); + } + + _ => { + help!(&mut err, + "perhaps you forgot parentheses? (per RFC 438)"); + } + } + err.emit(); + } let sp = mk_sp(lo, self.prev_span.hi); - let sum = ast::TyKind::ObjectSum(lhs, bounds); + let sum = TyKind::TraitObject(bounds); Ok(P(Ty {id: ast::DUMMY_NODE_ID, node: sum, span: sp})) } - /// Parse a type. - pub fn parse_ty(&mut self) -> PResult<'a, P<Ty>> { + /// Parse a type in restricted contexts where `+` is not permitted. + /// Example 1: `&'a TYPE` + /// `+` is prohibited to maintain operator priority (P(+) < P(&)). + /// Example 2: `value1 as TYPE + value2` + /// `+` is prohibited to avoid interactions with expression grammar. + pub fn parse_ty_no_plus(&mut self) -> PResult<'a, P<Ty>> { maybe_whole!(self, NtTy, |x| x); let lo = self.span.lo; @@ -1298,7 +1350,7 @@ impl<'a> Parser<'a> { let mut ts = vec![]; let mut last_comma = false; while self.token != token::CloseDelim(token::Paren) { - ts.push(self.parse_ty_sum()?); + ts.push(self.parse_ty()?); if self.check(&token::Comma) { last_comma = true; self.bump(); @@ -1323,7 +1375,7 @@ impl<'a> Parser<'a> { } else if self.check(&token::OpenDelim(token::Bracket)) { // VECTOR self.expect(&token::OpenDelim(token::Bracket))?; - let t = self.parse_ty_sum()?; + let t = self.parse_ty()?; // Parse the `; e` in `[ i32; e ]` // where `e` is a const expression @@ -1404,7 +1456,7 @@ impl<'a> Parser<'a> { `*mut T` or `*const T` as appropriate)"); Mutability::Immutable }; - let t = self.parse_ty()?; + let t = self.parse_ty_no_plus()?; Ok(MutTy { ty: t, mutbl: mutbl }) } @@ -1451,7 +1503,7 @@ impl<'a> Parser<'a> { }) }; - let t = self.parse_ty_sum()?; + let t = self.parse_ty()?; Ok(Arg { ty: t, @@ -1469,7 +1521,7 @@ impl<'a> Parser<'a> { pub fn parse_fn_block_arg(&mut self) -> PResult<'a, Arg> { let pat = self.parse_pat()?; let t = if self.eat(&token::Colon) { - self.parse_ty_sum()? + self.parse_ty()? } else { P(Ty { id: ast::DUMMY_NODE_ID, @@ -1610,7 +1662,7 @@ impl<'a> Parser<'a> { pub fn parse_qualified_path(&mut self, mode: PathStyle) -> PResult<'a, (QSelf, ast::Path)> { let span = self.prev_span; - let self_type = self.parse_ty_sum()?; + let self_type = self.parse_ty()?; let mut path = if self.eat_keyword(keywords::As) { self.parse_path(PathStyle::Type)? } else { @@ -1711,8 +1763,8 @@ impl<'a> Parser<'a> { let (lifetimes, types, bindings) = self.parse_generic_values_after_lt()?; ast::AngleBracketedParameterData { lifetimes: lifetimes, - types: P::from_vec(types), - bindings: P::from_vec(bindings), + types: types, + bindings: bindings, }.into() } else if self.eat(&token::OpenDelim(token::Paren)) { let lo = self.prev_span.lo; @@ -1720,10 +1772,10 @@ impl<'a> Parser<'a> { let inputs = self.parse_seq_to_end( &token::CloseDelim(token::Paren), SeqSep::trailing_allowed(token::Comma), - |p| p.parse_ty_sum())?; + |p| p.parse_ty())?; let output_ty = if self.eat(&token::RArrow) { - Some(self.parse_ty()?) + Some(self.parse_ty_no_plus()?) } else { None }; @@ -1771,8 +1823,8 @@ impl<'a> Parser<'a> { identifier: identifier, parameters: ast::AngleBracketedParameterData { lifetimes: lifetimes, - types: P::from_vec(types), - bindings: P::from_vec(bindings), + types: types, + bindings: bindings, }.into(), }); @@ -2933,12 +2985,12 @@ impl<'a> Parser<'a> { } // Special cases: if op == AssocOp::As { - let rhs = self.parse_ty()?; + let rhs = self.parse_ty_no_plus()?; let (lo, hi) = (lhs_span.lo, rhs.span.hi); lhs = self.mk_expr(lo, hi, ExprKind::Cast(lhs, rhs), ThinVec::new()); continue } else if op == AssocOp::Colon { - let rhs = self.parse_ty()?; + let rhs = self.parse_ty_no_plus()?; let (lo, hi) = (lhs_span.lo, rhs.span.hi); lhs = self.mk_expr(lo, hi, ExprKind::Type(lhs, rhs), ThinVec::new()); continue @@ -3706,7 +3758,7 @@ impl<'a> Parser<'a> { let mut ty = None; if self.eat(&token::Colon) { - ty = Some(self.parse_ty_sum()?); + ty = Some(self.parse_ty()?); } let init = self.parse_initializer()?; Ok(P(ast::Local { @@ -3727,7 +3779,7 @@ impl<'a> Parser<'a> { -> PResult<'a, StructField> { let name = self.parse_ident()?; self.expect(&token::Colon)?; - let ty = self.parse_ty_sum()?; + let ty = self.parse_ty()?; Ok(StructField { span: mk_sp(lo, self.prev_span.hi), ident: Some(name), @@ -4144,7 +4196,7 @@ impl<'a> Parser<'a> { fn parse_colon_then_ty_param_bounds(&mut self) -> PResult<'a, TyParamBounds> { if !self.eat(&token::Colon) { - Ok(P::new()) + Ok(Vec::new()) } else { self.parse_ty_param_bounds() } @@ -4190,7 +4242,7 @@ impl<'a> Parser<'a> { } } - return Ok(P::from_vec(result)); + return Ok(result); } /// Matches typaram = IDENT (`?` unbound)? optbounds ( EQ ty )? @@ -4202,7 +4254,7 @@ impl<'a> Parser<'a> { let default = if self.check(&token::Eq) { self.bump(); - Some(self.parse_ty_sum()?) + Some(self.parse_ty()?) } else { None }; @@ -4297,7 +4349,7 @@ impl<'a> Parser<'a> { let mut err = self.diagnostic().struct_span_err(self.span, &msg); let span_hi = self.span.hi; - let span_hi = match self.parse_ty() { + let span_hi = match self.parse_ty_no_plus() { Ok(..) => self.span.hi, Err(ref mut err) => { self.cancel(err); @@ -4320,14 +4372,14 @@ impl<'a> Parser<'a> { if p.look_ahead(1, |t| t == &token::Eq) { Ok(None) } else { - Ok(Some(p.parse_ty_sum()?)) + Ok(Some(p.parse_ty()?)) } } )?; // If we found the `>`, don't continue. if !returned { - return Ok((lifetimes, types.into_vec(), Vec::new())); + return Ok((lifetimes, types, Vec::new())); } // Then parse type bindings. @@ -4338,7 +4390,7 @@ impl<'a> Parser<'a> { let lo = p.span.lo; let ident = p.parse_ident()?; p.expect(&token::Eq)?; - let ty = p.parse_ty()?; + let ty = p.parse_ty_no_plus()?; let hi = ty.span.hi; let span = mk_sp(lo, hi); return Ok(TypeBinding{id: ast::DUMMY_NODE_ID, @@ -4348,7 +4400,7 @@ impl<'a> Parser<'a> { }); } )?; - Ok((lifetimes, types.into_vec(), bindings.into_vec())) + Ok((lifetimes, types, bindings)) } fn forbid_lifetime(&mut self) -> PResult<'a, ()> { @@ -4436,7 +4488,7 @@ impl<'a> Parser<'a> { vec![] }; - let bounded_ty = self.parse_ty()?; + let bounded_ty = self.parse_ty_no_plus()?; if self.eat(&token::Colon) { let bounds = self.parse_ty_param_bounds()?; @@ -4459,7 +4511,7 @@ impl<'a> Parser<'a> { parsed_something = true; } else if self.eat(&token::Eq) { - // let ty = try!(self.parse_ty()); + // let ty = try!(self.parse_ty_no_plus()); let hi = self.prev_span.hi; let span = mk_sp(lo, hi); // where_clause.predicates.push( @@ -4631,7 +4683,7 @@ impl<'a> Parser<'a> { // self: TYPE let eself_ident = expect_ident(self); if self.eat(&token::Colon) { - let ty = self.parse_ty_sum()?; + let ty = self.parse_ty()?; (SelfKind::Explicit(ty, Mutability::Immutable), eself_ident) } else { (SelfKind::Value(Mutability::Immutable), eself_ident) @@ -4643,7 +4695,7 @@ impl<'a> Parser<'a> { self.bump(); let eself_ident = expect_ident(self); if self.eat(&token::Colon) { - let ty = self.parse_ty_sum()?; + let ty = self.parse_ty()?; (SelfKind::Explicit(ty, Mutability::Mutable), eself_ident) } else { (SelfKind::Value(Mutability::Mutable), eself_ident) @@ -4800,14 +4852,14 @@ impl<'a> Parser<'a> { let (name, node) = if self.eat_keyword(keywords::Type) { let name = self.parse_ident()?; self.expect(&token::Eq)?; - let typ = self.parse_ty_sum()?; + let typ = self.parse_ty()?; self.expect(&token::Semi)?; (name, ast::ImplItemKind::Type(typ)) } else if self.is_const_item() { self.expect_keyword(keywords::Const)?; let name = self.parse_ident()?; self.expect(&token::Colon)?; - let typ = self.parse_ty_sum()?; + let typ = self.parse_ty()?; self.expect(&token::Eq)?; let expr = self.parse_expr()?; self.expect(&token::Semi)?; @@ -4931,7 +4983,7 @@ impl<'a> Parser<'a> { }; // Parse the trait. - let mut ty = self.parse_ty_sum()?; + let mut ty = self.parse_ty()?; // Parse traits, if necessary. let opt_trait = if could_be_trait && self.eat_keyword(keywords::For) { @@ -4972,7 +5024,7 @@ impl<'a> Parser<'a> { ItemKind::DefaultImpl(unsafety, opt_trait.unwrap()), None)) } else { if opt_trait.is_some() { - ty = self.parse_ty_sum()?; + ty = self.parse_ty()?; } generics.where_clause = self.parse_where_clause()?; @@ -5124,7 +5176,7 @@ impl<'a> Parser<'a> { let mut vis = p.parse_visibility(false)?; let ty_is_interpolated = p.token.is_interpolated() || p.look_ahead(1, |t| t.is_interpolated()); - let mut ty = p.parse_ty_sum()?; + let mut ty = p.parse_ty()?; // Handle `pub(path) type`, in which `vis` will be `pub` and `ty` will be `(path)`. if vis == Visibility::Public && !ty_is_interpolated && @@ -5132,7 +5184,7 @@ impl<'a> Parser<'a> { ty = if let TyKind::Paren(ref path_ty) = ty.node { if let TyKind::Path(None, ref path) = path_ty.node { vis = Visibility::Restricted { path: P(path.clone()), id: path_ty.id }; - Some(p.parse_ty_sum()?) + Some(p.parse_ty()?) } else { None } @@ -5250,7 +5302,7 @@ impl<'a> Parser<'a> { fn parse_item_const(&mut self, m: Option<Mutability>) -> PResult<'a, ItemInfo> { let id = self.parse_ident()?; self.expect(&token::Colon)?; - let ty = self.parse_ty_sum()?; + let ty = self.parse_ty()?; self.expect(&token::Eq)?; let e = self.parse_expr()?; self.expect(&token::Semi)?; @@ -5491,7 +5543,7 @@ impl<'a> Parser<'a> { let ident = self.parse_ident()?; self.expect(&token::Colon)?; - let ty = self.parse_ty_sum()?; + let ty = self.parse_ty()?; let hi = self.span.hi; self.expect(&token::Semi)?; Ok(ForeignItem { @@ -5580,7 +5632,7 @@ impl<'a> Parser<'a> { let mut tps = self.parse_generics()?; tps.where_clause = self.parse_where_clause()?; self.expect(&token::Eq)?; - let ty = self.parse_ty_sum()?; + let ty = self.parse_ty()?; self.expect(&token::Semi)?; Ok((ident, ItemKind::Ty(ty, tps), None)) } |