diff options
Diffstat (limited to 'compiler/rustc_parse/src/parser/item.rs')
| -rw-r--r-- | compiler/rustc_parse/src/parser/item.rs | 163 |
1 files changed, 118 insertions, 45 deletions
diff --git a/compiler/rustc_parse/src/parser/item.rs b/compiler/rustc_parse/src/parser/item.rs index e55b5ce71..bda301c52 100644 --- a/compiler/rustc_parse/src/parser/item.rs +++ b/compiler/rustc_parse/src/parser/item.rs @@ -1,4 +1,6 @@ -use super::diagnostics::{dummy_arg, ConsumeClosingDelim, Error}; +use crate::errors::{DocCommentDoesNotDocumentAnything, UseEmptyBlockNotSemi}; + +use super::diagnostics::{dummy_arg, ConsumeClosingDelim}; use super::ty::{AllowPlus, RecoverQPath, RecoverReturnSign}; use super::{AttrWrapper, FollowedByType, ForceCollect, Parser, PathStyle, TrailingToken}; @@ -13,7 +15,7 @@ use rustc_ast::{EnumDef, FieldDef, Generics, TraitRef, Ty, TyKind, Variant, Vari use rustc_ast::{FnHeader, ForeignItem, Path, PathSegment, Visibility, VisibilityKind}; use rustc_ast::{MacArgs, MacCall, MacDelimiter}; use rustc_ast_pretty::pprust; -use rustc_errors::{struct_span_err, Applicability, PResult, StashKey}; +use rustc_errors::{struct_span_err, Applicability, IntoDiagnostic, PResult, StashKey}; use rustc_span::edition::Edition; use rustc_span::lev_distance::lev_distance; use rustc_span::source_map::{self, Span}; @@ -664,6 +666,14 @@ impl<'a> Parser<'a> { mut parse_item: impl FnMut(&mut Parser<'a>) -> PResult<'a, Option<Option<T>>>, ) -> PResult<'a, Vec<T>> { let open_brace_span = self.token.span; + + // Recover `impl Ty;` instead of `impl Ty {}` + if self.token == TokenKind::Semi { + self.sess.emit_err(UseEmptyBlockNotSemi { span: self.token.span }); + self.bump(); + return Ok(vec![]); + } + self.expect(&token::OpenDelim(Delimiter::Brace))?; attrs.extend(self.parse_inner_attributes()?); @@ -750,8 +760,8 @@ impl<'a> Parser<'a> { ) .span_label(self.token.span, "this doc comment doesn't document anything") .help( - "doc comments must come before what they document, maybe a \ - comment was intended with `//`?", + "doc comments must come before what they document, if a comment was \ + intended use `//`", ) .emit(); self.bump(); @@ -1283,12 +1293,10 @@ impl<'a> Parser<'a> { /// Parses an enum declaration. fn parse_item_enum(&mut self) -> PResult<'a, ItemInfo> { if self.token.is_keyword(kw::Struct) { - let mut err = self.struct_span_err( - self.prev_token.span.to(self.token.span), - "`enum` and `struct` are mutually exclusive", - ); + let span = self.prev_token.span.to(self.token.span); + let mut err = self.struct_span_err(span, "`enum` and `struct` are mutually exclusive"); err.span_suggestion( - self.prev_token.span.to(self.token.span), + span, "replace `enum struct` with", "enum", Applicability::MachineApplicable, @@ -1305,12 +1313,20 @@ impl<'a> Parser<'a> { let mut generics = self.parse_generics()?; generics.where_clause = self.parse_where_clause()?; - let (variants, _) = self - .parse_delim_comma_seq(Delimiter::Brace, |p| p.parse_enum_variant()) - .map_err(|e| { - self.recover_stmt(); - e - })?; + // Possibly recover `enum Foo;` instead of `enum Foo {}` + let (variants, _) = if self.token == TokenKind::Semi { + self.sess.emit_err(UseEmptyBlockNotSemi { span: self.token.span }); + self.bump(); + (vec![], false) + } else { + self.parse_delim_comma_seq(Delimiter::Brace, |p| p.parse_enum_variant()).map_err( + |mut e| { + e.span_label(id.span, "while parsing this enum"); + self.recover_stmt(); + e + }, + )? + }; let enum_definition = EnumDef { variants: variants.into_iter().flatten().collect() }; Ok((id, ItemKind::Enum(enum_definition, generics))) @@ -1332,7 +1348,8 @@ impl<'a> Parser<'a> { let struct_def = if this.check(&token::OpenDelim(Delimiter::Brace)) { // Parse a struct variant. - let (fields, recovered) = this.parse_record_struct_body("struct", false)?; + let (fields, recovered) = + this.parse_record_struct_body("struct", ident.span, false)?; VariantData::Struct(fields, recovered) } else if this.check(&token::OpenDelim(Delimiter::Parenthesis)) { VariantData::Tuple(this.parse_tuple_struct_body()?, DUMMY_NODE_ID) @@ -1386,8 +1403,11 @@ impl<'a> Parser<'a> { VariantData::Unit(DUMMY_NODE_ID) } else { // If we see: `struct Foo<T> where T: Copy { ... }` - let (fields, recovered) = - self.parse_record_struct_body("struct", generics.where_clause.has_where_token)?; + let (fields, recovered) = self.parse_record_struct_body( + "struct", + class_name.span, + generics.where_clause.has_where_token, + )?; VariantData::Struct(fields, recovered) } // No `where` so: `struct Foo<T>;` @@ -1395,8 +1415,11 @@ impl<'a> Parser<'a> { VariantData::Unit(DUMMY_NODE_ID) // Record-style struct definition } else if self.token == token::OpenDelim(Delimiter::Brace) { - let (fields, recovered) = - self.parse_record_struct_body("struct", generics.where_clause.has_where_token)?; + let (fields, recovered) = self.parse_record_struct_body( + "struct", + class_name.span, + generics.where_clause.has_where_token, + )?; VariantData::Struct(fields, recovered) // Tuple-style struct definition with optional where-clause. } else if self.token == token::OpenDelim(Delimiter::Parenthesis) { @@ -1425,12 +1448,18 @@ impl<'a> Parser<'a> { let vdata = if self.token.is_keyword(kw::Where) { generics.where_clause = self.parse_where_clause()?; - let (fields, recovered) = - self.parse_record_struct_body("union", generics.where_clause.has_where_token)?; + let (fields, recovered) = self.parse_record_struct_body( + "union", + class_name.span, + generics.where_clause.has_where_token, + )?; VariantData::Struct(fields, recovered) } else if self.token == token::OpenDelim(Delimiter::Brace) { - let (fields, recovered) = - self.parse_record_struct_body("union", generics.where_clause.has_where_token)?; + let (fields, recovered) = self.parse_record_struct_body( + "union", + class_name.span, + generics.where_clause.has_where_token, + )?; VariantData::Struct(fields, recovered) } else { let token_str = super::token_descr(&self.token); @@ -1446,6 +1475,7 @@ impl<'a> Parser<'a> { fn parse_record_struct_body( &mut self, adt_ty: &str, + ident_span: Span, parsed_where: bool, ) -> PResult<'a, (Vec<FieldDef>, /* recovered */ bool)> { let mut fields = Vec::new(); @@ -1460,6 +1490,7 @@ impl<'a> Parser<'a> { match field { Ok(field) => fields.push(field), Err(mut err) => { + err.span_label(ident_span, format!("while parsing this {adt_ty}")); err.emit(); break; } @@ -1555,7 +1586,10 @@ impl<'a> Parser<'a> { token::CloseDelim(Delimiter::Brace) => {} token::DocComment(..) => { let previous_span = self.prev_token.span; - let mut err = self.span_err(self.token.span, Error::UselessDocComment); + let mut err = DocCommentDoesNotDocumentAnything { + span: self.token.span, + missing_comma: None, + }; self.bump(); // consume the doc comment let comma_after_doc_seen = self.eat(&token::Comma); // `seen_comma` is always false, because we are inside doc block @@ -1564,18 +1598,13 @@ impl<'a> Parser<'a> { seen_comma = true; } if comma_after_doc_seen || self.token == token::CloseDelim(Delimiter::Brace) { - err.emit(); + self.sess.emit_err(err); } else { if !seen_comma { - let sp = self.sess.source_map().next_point(previous_span); - err.span_suggestion( - sp, - "missing comma here", - ",", - Applicability::MachineApplicable, - ); + let sp = previous_span.shrink_to_hi(); + err.missing_comma = Some(sp); } - return Err(err); + return Err(err.into_diagnostic(&self.sess.span_diagnostic)); } } _ => { @@ -1715,6 +1744,7 @@ impl<'a> Parser<'a> { fn parse_field_ident(&mut self, adt_ty: &str, lo: Span) -> PResult<'a, Ident> { let (ident, is_raw) = self.ident_or_err()?; if !is_raw && ident.is_reserved() { + let snapshot = self.create_snapshot_for_diagnostic(); let err = if self.check_fn_front_matter(false) { let inherited_vis = Visibility { span: rustc_span::DUMMY_SP, @@ -1723,20 +1753,63 @@ impl<'a> Parser<'a> { }; // 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 AttrVec::new(), fn_parse_mode, lo, &inherited_vis) + match self.parse_fn(&mut AttrVec::new(), fn_parse_mode, lo, &inherited_vis) { + Ok(_) => { + let mut err = self.struct_span_err( + lo.to(self.prev_token.span), + &format!("functions are not allowed in {adt_ty} definitions"), + ); + err.help( + "unlike in C++, Java, and C#, functions are declared in `impl` blocks", + ); + err.help("see https://doc.rust-lang.org/book/ch05-03-method-syntax.html for more information"); + err + } + Err(err) => { + err.cancel(); + self.restore_snapshot(snapshot); + self.expected_ident_found() + } + } + } else if self.eat_keyword(kw::Struct) { + match self.parse_item_struct() { + Ok((ident, _)) => { + let mut err = self.struct_span_err( + lo.with_hi(ident.span.hi()), + &format!("structs are not allowed in {adt_ty} definitions"), + ); + err.help("consider creating a new `struct` definition instead of nesting"); + err + } + Err(err) => { + err.cancel(); + self.restore_snapshot(snapshot); + self.expected_ident_found() + } + } + } else { + let mut err = self.expected_ident_found(); + if self.eat_keyword_noexpect(kw::Let) + && let removal_span = self.prev_token.span.until(self.token.span) + && let Ok(ident) = self.parse_ident_common(false) + // Cancel this error, we don't need it. + .map_err(|err| err.cancel()) + && self.token.kind == TokenKind::Colon { - db.delay_as_bug(); + err.span_suggestion( + removal_span, + "remove this `let` keyword", + String::new(), + Applicability::MachineApplicable, + ); + err.note("the `let` keyword is not allowed in `struct` fields"); + err.note("see <https://doc.rust-lang.org/book/ch05-01-defining-structs.html> for more information"); + err.emit(); + return Ok(ident); + } else { + self.restore_snapshot(snapshot); } - let mut err = self.struct_span_err( - lo.to(self.prev_token.span), - &format!("functions are not allowed in {adt_ty} definitions"), - ); - err.help("unlike in C++, Java, and C#, functions are declared in `impl` blocks"); - err.help("see https://doc.rust-lang.org/book/ch05-03-method-syntax.html for more information"); err - } else { - self.expected_ident_found() }; return Err(err); } |