diff options
Diffstat (limited to 'compiler/rustc_parse/src/parser')
| -rw-r--r-- | compiler/rustc_parse/src/parser/item.rs | 112 | ||||
| -rw-r--r-- | compiler/rustc_parse/src/parser/ty.rs | 8 |
2 files changed, 90 insertions, 30 deletions
diff --git a/compiler/rustc_parse/src/parser/item.rs b/compiler/rustc_parse/src/parser/item.rs index 516e301ec3a..618aa3fd002 100644 --- a/compiler/rustc_parse/src/parser/item.rs +++ b/compiler/rustc_parse/src/parser/item.rs @@ -223,7 +223,7 @@ impl<'a> Parser<'a> { (Ident::empty(), ItemKind::Use(tree)) } else if self.check_fn_front_matter(def_final) { // FUNCTION ITEM - let (ident, sig, generics, body) = self.parse_fn(attrs, fn_parse_mode, lo)?; + let (ident, sig, generics, body) = self.parse_fn(attrs, fn_parse_mode, lo, vis)?; (ident, ItemKind::Fn(Box::new(Fn { defaultness: def(), sig, generics, body }))) } else if self.eat_keyword(kw::Extern) { if self.eat_keyword(kw::Crate) { @@ -1511,9 +1511,16 @@ impl<'a> Parser<'a> { let (ident, is_raw) = self.ident_or_err()?; if !is_raw && ident.is_reserved() { let err = if self.check_fn_front_matter(false) { + let inherited_vis = Visibility { + span: rustc_span::DUMMY_SP, + kind: VisibilityKind::Inherited, + tokens: None, + }; // We use `parse_fn` to get a span for the function let fn_parse_mode = FnParseMode { req_name: |_| true, req_body: true }; - if let Err(mut db) = self.parse_fn(&mut Vec::new(), fn_parse_mode, lo) { + if let Err(mut db) = + self.parse_fn(&mut Vec::new(), fn_parse_mode, lo, &inherited_vis) + { db.delay_as_bug(); } let mut err = self.struct_span_err( @@ -1793,8 +1800,9 @@ impl<'a> Parser<'a> { attrs: &mut Vec<Attribute>, fn_parse_mode: FnParseMode, sig_lo: Span, + vis: &Visibility, ) -> PResult<'a, (Ident, FnSig, Generics, Option<P<Block>>)> { - let header = self.parse_fn_front_matter()?; // `const ... fn` + let header = self.parse_fn_front_matter(vis)?; // `const ... fn` let ident = self.parse_ident()?; // `foo` let mut generics = self.parse_generics()?; // `<'a, T, ...>` let decl = @@ -1903,12 +1911,15 @@ impl<'a> Parser<'a> { /// Parses all the "front matter" (or "qualifiers") for a `fn` declaration, /// up to and including the `fn` keyword. The formal grammar is: /// - /// ``` + /// ```text /// Extern = "extern" StringLit? ; /// FnQual = "const"? "async"? "unsafe"? Extern? ; /// FnFrontMatter = FnQual "fn" ; /// ``` - pub(super) fn parse_fn_front_matter(&mut self) -> PResult<'a, FnHeader> { + /// + /// `vis` represents the visibility that was already parsed, if any. Use + /// `Visibility::Inherited` when no visibility is known. + pub(super) fn parse_fn_front_matter(&mut self, orig_vis: &Visibility) -> PResult<'a, FnHeader> { let sp_start = self.token.span; let constness = self.parse_constness(); @@ -1934,51 +1945,94 @@ impl<'a> Parser<'a> { Ok(false) => unreachable!(), Err(mut err) => { // Qualifier keywords ordering check + enum WrongKw { + Duplicated(Span), + Misplaced(Span), + } - // This will allow the machine fix to directly place the keyword in the correct place - let current_qual_sp = if self.check_keyword(kw::Const) { - Some(async_start_sp) + // This will allow the machine fix to directly place the keyword in the correct place or to indicate + // that the keyword is already present and the second instance should be removed. + let wrong_kw = if self.check_keyword(kw::Const) { + match constness { + Const::Yes(sp) => Some(WrongKw::Duplicated(sp)), + Const::No => Some(WrongKw::Misplaced(async_start_sp)), + } } else if self.check_keyword(kw::Async) { - Some(unsafe_start_sp) + match asyncness { + Async::Yes { span, .. } => Some(WrongKw::Duplicated(span)), + Async::No => Some(WrongKw::Misplaced(unsafe_start_sp)), + } } else if self.check_keyword(kw::Unsafe) { - Some(ext_start_sp) + match unsafety { + Unsafe::Yes(sp) => Some(WrongKw::Duplicated(sp)), + Unsafe::No => Some(WrongKw::Misplaced(ext_start_sp)), + } } else { None }; - if let Some(current_qual_sp) = current_qual_sp { - let current_qual_sp = current_qual_sp.to(self.prev_token.span); - if let Ok(current_qual) = self.span_to_snippet(current_qual_sp) { - let invalid_qual_sp = self.token.uninterpolated_span(); - let invalid_qual = self.span_to_snippet(invalid_qual_sp).unwrap(); + // The keyword is already present, suggest removal of the second instance + if let Some(WrongKw::Duplicated(original_sp)) = wrong_kw { + let original_kw = self + .span_to_snippet(original_sp) + .expect("Span extracted directly from keyword should always work"); + + err.span_suggestion( + self.token.uninterpolated_span(), + &format!("`{}` already used earlier, remove this one", original_kw), + "".to_string(), + Applicability::MachineApplicable, + ) + .span_note(original_sp, &format!("`{}` first seen here", original_kw)); + } + // The keyword has not been seen yet, suggest correct placement in the function front matter + else if let Some(WrongKw::Misplaced(correct_pos_sp)) = wrong_kw { + let correct_pos_sp = correct_pos_sp.to(self.prev_token.span); + if let Ok(current_qual) = self.span_to_snippet(correct_pos_sp) { + let misplaced_qual_sp = self.token.uninterpolated_span(); + let misplaced_qual = self.span_to_snippet(misplaced_qual_sp).unwrap(); err.span_suggestion( - current_qual_sp.to(invalid_qual_sp), - &format!("`{}` must come before `{}`", invalid_qual, current_qual), - format!("{} {}", invalid_qual, current_qual), - Applicability::MachineApplicable, - ).note("keyword order for functions declaration is `default`, `pub`, `const`, `async`, `unsafe`, `extern`"); + correct_pos_sp.to(misplaced_qual_sp), + &format!("`{}` must come before `{}`", misplaced_qual, current_qual), + format!("{} {}", misplaced_qual, current_qual), + Applicability::MachineApplicable, + ).note("keyword order for functions declaration is `default`, `pub`, `const`, `async`, `unsafe`, `extern`"); } } - // Recover incorrect visibility order such as `async pub`. + // Recover incorrect visibility order such as `async pub` else if self.check_keyword(kw::Pub) { let sp = sp_start.to(self.prev_token.span); if let Ok(snippet) = self.span_to_snippet(sp) { - let vis = match self.parse_visibility(FollowedByType::No) { + let current_vis = match self.parse_visibility(FollowedByType::No) { Ok(v) => v, Err(mut d) => { d.cancel(); return Err(err); } }; - let vs = pprust::vis_to_string(&vis); + let vs = pprust::vis_to_string(¤t_vis); let vs = vs.trim_end(); - err.span_suggestion( - sp_start.to(self.prev_token.span), - &format!("visibility `{}` must come before `{}`", vs, snippet), - format!("{} {}", vs, snippet), - Applicability::MachineApplicable, - ); + + // There was no explicit visibility + if matches!(orig_vis.kind, VisibilityKind::Inherited) { + err.span_suggestion( + sp_start.to(self.prev_token.span), + &format!("visibility `{}` must come before `{}`", vs, snippet), + format!("{} {}", vs, snippet), + Applicability::MachineApplicable, + ); + } + // There was an explicit visibility + else { + err.span_suggestion( + current_vis.span, + "there is already a visibility modifier, remove one", + "".to_string(), + Applicability::MachineApplicable, + ) + .span_note(orig_vis.span, "explicit visibility first seen here"); + } } } return Err(err); diff --git a/compiler/rustc_parse/src/parser/ty.rs b/compiler/rustc_parse/src/parser/ty.rs index 9bfde0e3900..02a774ba129 100644 --- a/compiler/rustc_parse/src/parser/ty.rs +++ b/compiler/rustc_parse/src/parser/ty.rs @@ -474,7 +474,13 @@ impl<'a> Parser<'a> { params: Vec<GenericParam>, recover_return_sign: RecoverReturnSign, ) -> PResult<'a, TyKind> { - let ast::FnHeader { ext, unsafety, constness, asyncness } = self.parse_fn_front_matter()?; + let inherited_vis = rustc_ast::Visibility { + span: rustc_span::DUMMY_SP, + kind: rustc_ast::VisibilityKind::Inherited, + tokens: None, + }; + let ast::FnHeader { ext, unsafety, constness, asyncness } = + self.parse_fn_front_matter(&inherited_vis)?; let decl = self.parse_fn_decl(|_| false, AllowPlus::No, recover_return_sign)?; let whole_span = lo.to(self.prev_token.span); if let ast::Const::Yes(span) = constness { |