diff options
Diffstat (limited to 'compiler/rustc_parse/src/parser/ty.rs')
-rw-r--r-- | compiler/rustc_parse/src/parser/ty.rs | 204 |
1 files changed, 69 insertions, 135 deletions
diff --git a/compiler/rustc_parse/src/parser/ty.rs b/compiler/rustc_parse/src/parser/ty.rs index 400c8dbe9..a29b696ae 100644 --- a/compiler/rustc_parse/src/parser/ty.rs +++ b/compiler/rustc_parse/src/parser/ty.rs @@ -1,10 +1,9 @@ use super::{Parser, PathStyle, TokenType}; use crate::errors::{ - DynAfterMut, ExpectedFnPathFoundFnKeyword, ExpectedMutOrConstInRawPointerType, + self, DynAfterMut, ExpectedFnPathFoundFnKeyword, ExpectedMutOrConstInRawPointerType, FnPointerCannotBeAsync, FnPointerCannotBeConst, FnPtrWithGenerics, FnPtrWithGenericsSugg, - InvalidDynKeyword, LifetimeAfterMut, NeedPlusAfterTraitObjectLifetime, - NegativeBoundsNotSupported, NegativeBoundsNotSupportedSugg, NestedCVariadicType, + InvalidDynKeyword, LifetimeAfterMut, NeedPlusAfterTraitObjectLifetime, NestedCVariadicType, ReturnTypesUseThinArrow, }; use crate::{maybe_recover_from_interpolated_ty_qpath, maybe_whole}; @@ -14,8 +13,9 @@ use rustc_ast::ptr::P; use rustc_ast::token::{self, Delimiter, Token, TokenKind}; use rustc_ast::util::case::Case; use rustc_ast::{ - self as ast, BareFnTy, FnRetTy, GenericBound, GenericBounds, GenericParam, Generics, Lifetime, - MacCall, MutTy, Mutability, PolyTraitRef, TraitBoundModifier, TraitObjectSyntax, Ty, TyKind, + self as ast, BareFnTy, BoundPolarity, FnRetTy, GenericBound, GenericBounds, GenericParam, + Generics, Lifetime, MacCall, MutTy, Mutability, PolyTraitRef, TraitBoundModifier, + TraitObjectSyntax, Ty, TyKind, }; use rustc_errors::{Applicability, PResult}; use rustc_span::source_map::Span; @@ -23,10 +23,10 @@ use rustc_span::symbol::{kw, sym, Ident}; use rustc_span::Symbol; use thin_vec::{thin_vec, ThinVec}; -/// Any `?` or `~const` modifiers that appear at the start of a bound. +/// Any `?`, `!`, or `~const` modifiers that appear at the start of a bound. struct BoundModifiers { /// `?Trait`. - maybe: Option<Span>, + bound_polarity: BoundPolarity, /// `~const Trait`. maybe_const: Option<Span>, @@ -34,11 +34,13 @@ struct BoundModifiers { impl BoundModifiers { fn to_trait_bound_modifier(&self) -> TraitBoundModifier { - match (self.maybe, self.maybe_const) { - (None, None) => TraitBoundModifier::None, - (Some(_), None) => TraitBoundModifier::Maybe, - (None, Some(_)) => TraitBoundModifier::MaybeConst, - (Some(_), Some(_)) => TraitBoundModifier::MaybeConstMaybe, + match (self.bound_polarity, self.maybe_const) { + (BoundPolarity::Positive, None) => TraitBoundModifier::None, + (BoundPolarity::Negative(_), None) => TraitBoundModifier::Negative, + (BoundPolarity::Maybe(_), None) => TraitBoundModifier::Maybe, + (BoundPolarity::Positive, Some(_)) => TraitBoundModifier::MaybeConst, + (BoundPolarity::Negative(_), Some(_)) => TraitBoundModifier::MaybeConstNegative, + (BoundPolarity::Maybe(_), Some(_)) => TraitBoundModifier::MaybeConstMaybe, } } } @@ -315,9 +317,8 @@ impl<'a> Parser<'a> { } } else { let msg = format!("expected type, found {}", super::token_descr(&self.token)); - let mut err = self.struct_span_err(self.token.span, &msg); + let mut err = self.struct_span_err(self.token.span, msg); err.span_label(self.token.span, "expected type"); - self.maybe_annotate_with_ascription(&mut err, true); return Err(err); }; @@ -369,7 +370,7 @@ impl<'a> Parser<'a> { fn parse_bare_trait_object(&mut self, lo: Span, allow_plus: AllowPlus) -> PResult<'a, TyKind> { let lt_no_plus = self.check_lifetime() && !self.look_ahead(1, |t| t.is_like_plus()); - let bounds = self.parse_generic_bounds_common(allow_plus, None)?; + let bounds = self.parse_generic_bounds_common(allow_plus)?; if lt_no_plus { self.sess.emit_err(NeedPlusAfterTraitObjectLifetime { span: lo }); } @@ -396,7 +397,7 @@ impl<'a> Parser<'a> { ) -> PResult<'a, TyKind> { if plus { self.eat_plus(); // `+`, or `+=` gets split and `+` is discarded - bounds.append(&mut self.parse_generic_bounds(Some(self.prev_token.span))?); + bounds.append(&mut self.parse_generic_bounds()?); } Ok(TyKind::TraitObject(bounds, TraitObjectSyntax::None)) } @@ -588,24 +589,18 @@ impl<'a> Parser<'a> { // Always parse bounds greedily for better error recovery. if self.token.is_lifetime() { self.look_ahead(1, |t| { - if let token::Ident(symname, _) = t.kind { + if let token::Ident(sym, _) = t.kind { // parse pattern with "'a Sized" we're supposed to give suggestion like // "'a + Sized" - self.struct_span_err( - self.token.span, - &format!("expected `+` between lifetime and {}", symname), - ) - .span_suggestion_verbose( - self.token.span.shrink_to_hi(), - "add `+`", - " +", - Applicability::MaybeIncorrect, - ) - .emit(); + self.sess.emit_err(errors::MissingPlusBounds { + span: self.token.span, + hi: self.token.span.shrink_to_hi(), + sym, + }); } }) } - let bounds = self.parse_generic_bounds(None)?; + let bounds = self.parse_generic_bounds()?; *impl_dyn_multi = bounds.len() > 1 || self.prev_token.kind == TokenKind::BinOp(token::Plus); Ok(TyKind::ImplTrait(ast::DUMMY_NODE_ID, bounds)) } @@ -636,7 +631,7 @@ impl<'a> Parser<'a> { }; // Always parse bounds greedily for better error recovery. - let bounds = self.parse_generic_bounds(None)?; + let bounds = self.parse_generic_bounds()?; *impl_dyn_multi = bounds.len() > 1 || self.prev_token.kind == TokenKind::BinOp(token::Plus); Ok(TyKind::TraitObject(bounds, syntax)) } @@ -657,11 +652,7 @@ impl<'a> Parser<'a> { let path = self.parse_path_inner(PathStyle::Type, ty_generics)?; if self.eat(&token::Not) { // Macro invocation in type position - Ok(TyKind::MacCall(P(MacCall { - path, - args: self.parse_delim_args()?, - prior_type_ascription: self.last_type_ascription, - }))) + Ok(TyKind::MacCall(P(MacCall { path, args: self.parse_delim_args()? }))) } else if allow_plus == AllowPlus::Yes && self.check_plus() { // `Trait1 + Trait2 + 'a` self.parse_remaining_bounds_path(ThinVec::new(), path, lo, true) @@ -671,23 +662,15 @@ impl<'a> Parser<'a> { } } - pub(super) fn parse_generic_bounds( - &mut self, - colon_span: Option<Span>, - ) -> PResult<'a, GenericBounds> { - self.parse_generic_bounds_common(AllowPlus::Yes, colon_span) + pub(super) fn parse_generic_bounds(&mut self) -> PResult<'a, GenericBounds> { + self.parse_generic_bounds_common(AllowPlus::Yes) } /// Parses bounds of a type parameter `BOUND + BOUND + ...`, possibly with trailing `+`. /// /// See `parse_generic_bound` for the `BOUND` grammar. - fn parse_generic_bounds_common( - &mut self, - allow_plus: AllowPlus, - colon_span: Option<Span>, - ) -> PResult<'a, GenericBounds> { + fn parse_generic_bounds_common(&mut self, allow_plus: AllowPlus) -> PResult<'a, GenericBounds> { let mut bounds = Vec::new(); - let mut negative_bounds = Vec::new(); // In addition to looping while we find generic bounds: // We continue even if we find a keyword. This is necessary for error recovery on, @@ -704,19 +687,12 @@ impl<'a> Parser<'a> { self.sess.emit_err(InvalidDynKeyword { span: self.token.span }); self.bump(); } - match self.parse_generic_bound()? { - Ok(bound) => bounds.push(bound), - Err(neg_sp) => negative_bounds.push(neg_sp), - } + bounds.push(self.parse_generic_bound()?); if allow_plus == AllowPlus::No || !self.eat_plus() { break; } } - if !negative_bounds.is_empty() { - self.error_negative_bounds(colon_span, &bounds, negative_bounds); - } - Ok(bounds) } @@ -724,55 +700,22 @@ impl<'a> Parser<'a> { fn can_begin_bound(&mut self) -> bool { // This needs to be synchronized with `TokenKind::can_begin_bound`. self.check_path() - || self.check_lifetime() - || self.check(&token::Not) // Used for error reporting only. - || self.check(&token::Question) - || self.check(&token::Tilde) - || self.check_keyword(kw::For) - || self.check(&token::OpenDelim(Delimiter::Parenthesis)) - } - - fn error_negative_bounds( - &self, - colon_span: Option<Span>, - bounds: &[GenericBound], - negative_bounds: Vec<Span>, - ) { - let sub = if let Some(bound_list) = colon_span { - let bound_list = bound_list.to(self.prev_token.span); - let mut new_bound_list = String::new(); - if !bounds.is_empty() { - let mut snippets = bounds.iter().map(|bound| self.span_to_snippet(bound.span())); - while let Some(Ok(snippet)) = snippets.next() { - new_bound_list.push_str(" + "); - new_bound_list.push_str(&snippet); - } - new_bound_list = new_bound_list.replacen(" +", ":", 1); - } - - Some(NegativeBoundsNotSupportedSugg { - bound_list, - num_bounds: negative_bounds.len(), - fixed: new_bound_list, - }) - } else { - None - }; - - let last_span = *negative_bounds.last().expect("no negative bounds, but still error?"); - self.sess.emit_err(NegativeBoundsNotSupported { negative_bounds, last_span, sub }); + || self.check_lifetime() + || self.check(&token::Not) + || self.check(&token::Question) + || self.check(&token::Tilde) + || self.check_keyword(kw::For) + || self.check(&token::OpenDelim(Delimiter::Parenthesis)) } /// Parses a bound according to the grammar: /// ```ebnf /// BOUND = TY_BOUND | LT_BOUND /// ``` - fn parse_generic_bound(&mut self) -> PResult<'a, Result<GenericBound, Span>> { - let anchor_lo = self.prev_token.span; + fn parse_generic_bound(&mut self) -> PResult<'a, GenericBound> { let lo = self.token.span; let has_parens = self.eat(&token::OpenDelim(Delimiter::Parenthesis)); let inner_lo = self.token.span; - let is_negative = self.eat(&token::Not); let modifiers = self.parse_ty_bound_modifiers()?; let bound = if self.token.is_lifetime() { @@ -782,7 +725,7 @@ impl<'a> Parser<'a> { self.parse_generic_ty_bound(lo, has_parens, modifiers)? }; - Ok(if is_negative { Err(anchor_lo.to(self.prev_token.span)) } else { Ok(bound) }) + Ok(bound) } /// Parses a lifetime ("outlives") bound, e.g. `'a`, according to: @@ -807,16 +750,17 @@ impl<'a> Parser<'a> { /// Emits an error if any trait bound modifiers were present. fn error_lt_bound_with_modifiers(&self, modifiers: BoundModifiers) { if let Some(span) = modifiers.maybe_const { - self.struct_span_err( - span, - "`~const` may only modify trait bounds, not lifetime bounds", - ) - .emit(); + self.sess.emit_err(errors::TildeConstLifetime { span }); } - if let Some(span) = modifiers.maybe { - self.struct_span_err(span, "`?` may only modify trait bounds, not lifetime bounds") - .emit(); + match modifiers.bound_polarity { + BoundPolarity::Positive => {} + BoundPolarity::Negative(span) => { + self.sess.emit_err(errors::ModifierLifetime { span, sigil: "!" }); + } + BoundPolarity::Maybe(span) => { + self.sess.emit_err(errors::ModifierLifetime { span, sigil: "?" }); + } } } @@ -824,19 +768,14 @@ impl<'a> Parser<'a> { fn recover_paren_lifetime(&mut self, lo: Span, inner_lo: Span) -> PResult<'a, ()> { let inner_span = inner_lo.to(self.prev_token.span); self.expect(&token::CloseDelim(Delimiter::Parenthesis))?; - let mut err = self.struct_span_err( - lo.to(self.prev_token.span), - "parenthesized lifetime bounds are not supported", - ); - if let Ok(snippet) = self.span_to_snippet(inner_span) { - err.span_suggestion_short( - lo.to(self.prev_token.span), - "remove the parentheses", - snippet, - Applicability::MachineApplicable, - ); - } - err.emit(); + let span = lo.to(self.prev_token.span); + let (sugg, snippet) = if let Ok(snippet) = self.span_to_snippet(inner_span) { + (Some(span), snippet) + } else { + (None, String::new()) + }; + + self.sess.emit_err(errors::ParenthesizedLifetime { span, sugg, snippet }); Ok(()) } @@ -857,24 +796,23 @@ impl<'a> Parser<'a> { } else if self.eat_keyword(kw::Const) { let span = self.prev_token.span; self.sess.gated_spans.gate(sym::const_trait_impl, span); - - self.struct_span_err(span, "const bounds must start with `~`") - .span_suggestion( - span.shrink_to_lo(), - "add `~`", - "~", - Applicability::MachineApplicable, - ) - .emit(); + self.sess.emit_err(errors::ConstMissingTilde { span, start: span.shrink_to_lo() }); Some(span) } else { None }; - let maybe = self.eat(&token::Question).then_some(self.prev_token.span); + let bound_polarity = if self.eat(&token::Question) { + BoundPolarity::Maybe(self.prev_token.span) + } else if self.eat(&token::Not) { + self.sess.gated_spans.gate(sym::negative_bounds, self.prev_token.span); + BoundPolarity::Negative(self.prev_token.span) + } else { + BoundPolarity::Positive + }; - Ok(BoundModifiers { maybe, maybe_const }) + Ok(BoundModifiers { bound_polarity, maybe_const }) } /// Parses a type bound according to: @@ -944,14 +882,10 @@ impl<'a> Parser<'a> { self.parse_remaining_bounds(bounds, true)?; self.expect(&token::CloseDelim(Delimiter::Parenthesis))?; let sp = vec![lo, self.prev_token.span]; - let sugg = vec![(lo, String::from(" ")), (self.prev_token.span, String::new())]; - self.struct_span_err(sp, "incorrect braces around trait bounds") - .multipart_suggestion( - "remove the parentheses", - sugg, - Applicability::MachineApplicable, - ) - .emit(); + self.sess.emit_err(errors::IncorrectBracesTraitBounds { + span: sp, + sugg: errors::IncorrectBracesTraitBoundsSugg { l: lo, r: self.prev_token.span }, + }); } else { self.expect(&token::CloseDelim(Delimiter::Parenthesis))?; } |