diff options
Diffstat (limited to 'compiler/rustc_parse/src/parser')
| -rw-r--r-- | compiler/rustc_parse/src/parser/diagnostics.rs | 119 | ||||
| -rw-r--r-- | compiler/rustc_parse/src/parser/expr.rs | 105 | ||||
| -rw-r--r-- | compiler/rustc_parse/src/parser/item.rs | 2 | ||||
| -rw-r--r-- | compiler/rustc_parse/src/parser/mod.rs | 23 | ||||
| -rw-r--r-- | compiler/rustc_parse/src/parser/pat.rs | 10 | ||||
| -rw-r--r-- | compiler/rustc_parse/src/parser/path.rs | 73 | ||||
| -rw-r--r-- | compiler/rustc_parse/src/parser/stmt.rs | 127 | ||||
| -rw-r--r-- | compiler/rustc_parse/src/parser/ty.rs | 7 |
8 files changed, 274 insertions, 192 deletions
diff --git a/compiler/rustc_parse/src/parser/diagnostics.rs b/compiler/rustc_parse/src/parser/diagnostics.rs index 0e041df898c..bcc76c20815 100644 --- a/compiler/rustc_parse/src/parser/diagnostics.rs +++ b/compiler/rustc_parse/src/parser/diagnostics.rs @@ -4,7 +4,7 @@ use super::{ TokenExpectType, TokenType, }; use crate::errors::{ - AmbiguousPlus, AttributeOnParamType, BadQPathStage2, BadTypePlus, BadTypePlusSub, + AmbiguousPlus, AttributeOnParamType, BadQPathStage2, BadTypePlus, BadTypePlusSub, ColonAsSemi, ComparisonOperatorsCannotBeChained, ComparisonOperatorsCannotBeChainedSugg, ConstGenericWithoutBraces, ConstGenericWithoutBracesSugg, DocCommentDoesNotDocumentAnything, DocCommentOnParamType, DoubleColonInBound, ExpectedIdentifier, ExpectedSemi, ExpectedSemiSugg, @@ -84,6 +84,7 @@ impl RecoverQPath for Ty { } impl RecoverQPath for Pat { + const PATH_STYLE: PathStyle = PathStyle::Pat; fn to_ty(&self) -> Option<P<Ty>> { self.to_ty() } @@ -237,6 +238,7 @@ impl<'a> DerefMut for SnapshotParser<'a> { impl<'a> Parser<'a> { #[rustc_lint_diagnostics] + #[track_caller] pub fn struct_span_err<S: Into<MultiSpan>>( &self, sp: S, @@ -663,7 +665,6 @@ impl<'a> Parser<'a> { err.span_label(sp, label_exp); err.span_label(self.token.span, "unexpected token"); } - self.maybe_annotate_with_ascription(&mut err, false); Err(err) } @@ -788,59 +789,6 @@ impl<'a> Parser<'a> { None } - pub fn maybe_annotate_with_ascription( - &mut self, - err: &mut Diagnostic, - maybe_expected_semicolon: bool, - ) { - if let Some((sp, likely_path)) = self.last_type_ascription.take() { - let sm = self.sess.source_map(); - let next_pos = sm.lookup_char_pos(self.token.span.lo()); - let op_pos = sm.lookup_char_pos(sp.hi()); - - let allow_unstable = self.sess.unstable_features.is_nightly_build(); - - if likely_path { - err.span_suggestion( - sp, - "maybe write a path separator here", - "::", - if allow_unstable { - Applicability::MaybeIncorrect - } else { - Applicability::MachineApplicable - }, - ); - self.sess.type_ascription_path_suggestions.borrow_mut().insert(sp); - } else if op_pos.line != next_pos.line && maybe_expected_semicolon { - err.span_suggestion( - sp, - "try using a semicolon", - ";", - Applicability::MaybeIncorrect, - ); - } else if allow_unstable { - err.span_label(sp, "tried to parse a type due to this type ascription"); - } else { - err.span_label(sp, "tried to parse a type due to this"); - } - if allow_unstable { - // Give extra information about type ascription only if it's a nightly compiler. - err.note( - "`#![feature(type_ascription)]` lets you annotate an expression with a type: \ - `<expr>: <type>`", - ); - if !likely_path { - // Avoid giving too much info when it was likely an unrelated typo. - err.note( - "see issue #23416 <https://github.com/rust-lang/rust/issues/23416> \ - for more information", - ); - } - } - } - } - /// Eats and discards tokens until one of `kets` is encountered. Respects token trees, /// passes through any errors encountered. Used for error recovery. pub(super) fn eat_to_tokens(&mut self, kets: &[&TokenKind]) { @@ -1625,9 +1573,40 @@ impl<'a> Parser<'a> { if self.eat(&token::Semi) { return Ok(()); } + + if self.recover_colon_as_semi() { + return Ok(()); + } + self.expect(&token::Semi).map(drop) // Error unconditionally } + pub(super) fn recover_colon_as_semi(&mut self) -> bool { + let line_idx = |span: Span| { + self.sess + .source_map() + .span_to_lines(span) + .ok() + .and_then(|lines| Some(lines.lines.get(0)?.line_index)) + }; + + if self.may_recover() + && self.token == token::Colon + && self.look_ahead(1, |next| line_idx(self.token.span) < line_idx(next.span)) + { + self.sess.emit_err(ColonAsSemi { + span: self.token.span, + type_ascription: self.sess.unstable_features.is_nightly_build().then_some(()), + }); + + self.bump(); + + return true; + } + + false + } + /// Consumes alternative await syntaxes like `await!(<expr>)`, `await <expr>`, /// `await? <expr>`, `await(<expr>)`, and `await { <expr> }`. pub(super) fn recover_incorrect_await_syntax( @@ -1790,37 +1769,27 @@ impl<'a> Parser<'a> { } } - pub(super) fn could_ascription_be_path(&self, node: &ast::ExprKind) -> bool { - (self.token == token::Lt && // `foo:<bar`, likely a typoed turbofish. - self.look_ahead(1, |t| t.is_ident() && !t.is_reserved_ident())) - || self.token.is_ident() && - matches!(node, ast::ExprKind::Path(..) | ast::ExprKind::Field(..)) && - !self.token.is_reserved_ident() && // v `foo:bar(baz)` - self.look_ahead(1, |t| t == &token::OpenDelim(Delimiter::Parenthesis)) - || self.look_ahead(1, |t| t == &token::OpenDelim(Delimiter::Brace)) // `foo:bar {` - || self.look_ahead(1, |t| t == &token::Colon) && // `foo:bar::<baz` - self.look_ahead(2, |t| t == &token::Lt) && - self.look_ahead(3, |t| t.is_ident()) - || self.look_ahead(1, |t| t == &token::Colon) && // `foo:bar:baz` - self.look_ahead(2, |t| t.is_ident()) - || self.look_ahead(1, |t| t == &token::ModSep) - && (self.look_ahead(2, |t| t.is_ident()) || // `foo:bar::baz` - self.look_ahead(2, |t| t == &token::Lt)) // `foo:bar::<baz>` - } - pub(super) fn recover_seq_parse_error( &mut self, delim: Delimiter, lo: Span, result: PResult<'a, P<Expr>>, ) -> P<Expr> { + use crate::parser::DUMMY_NODE_ID; match result { Ok(x) => x, Err(mut err) => { err.emit(); // Recover from parse error, callers expect the closing delim to be consumed. self.consume_block(delim, ConsumeClosingDelim::Yes); - self.mk_expr(lo.to(self.prev_token.span), ExprKind::Err) + debug!("recover_seq_parse_error: consumed tokens until {:?} {:?}", lo, self.token); + let res = self.mk_expr(lo.to(self.prev_token.span), ExprKind::Err); + if res.id == DUMMY_NODE_ID { + //panic!("debug now ....: {:?}", res); + res + } else { + res + } } } } @@ -1902,7 +1871,7 @@ impl<'a> Parser<'a> { && brace_depth == 0 && bracket_depth == 0 => { - debug!("recover_stmt_ return - Semi"); + debug!("recover_stmt_ return - Comma"); break; } _ => self.bump(), diff --git a/compiler/rustc_parse/src/parser/expr.rs b/compiler/rustc_parse/src/parser/expr.rs index bff9de5c652..7c55ac9cce2 100644 --- a/compiler/rustc_parse/src/parser/expr.rs +++ b/compiler/rustc_parse/src/parser/expr.rs @@ -174,10 +174,8 @@ impl<'a> Parser<'a> { self.parse_expr_prefix(attrs)? } }; - let last_type_ascription_set = self.last_type_ascription.is_some(); if !self.should_continue_as_assoc_expr(&lhs) { - self.last_type_ascription = None; return Ok(lhs); } @@ -296,14 +294,22 @@ impl<'a> Parser<'a> { continue; } + // Special cases: + if op.node == AssocOp::As { + lhs = self.parse_assoc_op_cast(lhs, lhs_span, ExprKind::Cast)?; + continue; + } else if op.node == AssocOp::DotDot || op.node == AssocOp::DotDotEq { + // If we didn't have to handle `x..`/`x..=`, it would be pretty easy to + // generalise it to the Fixity::None code. + lhs = self.parse_expr_range(prec, lhs, op.node, cur_op_span)?; + break; + } + let op = op.node; // Special cases: if op == AssocOp::As { lhs = self.parse_assoc_op_cast(lhs, lhs_span, ExprKind::Cast)?; continue; - } else if op == AssocOp::Colon { - lhs = self.parse_assoc_op_ascribe(lhs, lhs_span)?; - continue; } else if op == AssocOp::DotDot || op == AssocOp::DotDotEq { // If we didn't have to handle `x..`/`x..=`, it would be pretty easy to // generalise it to the Fixity::None code. @@ -364,7 +370,7 @@ impl<'a> Parser<'a> { let aopexpr = self.mk_assign_op(source_map::respan(cur_op_span, aop), lhs, rhs); self.mk_expr(span, aopexpr) } - AssocOp::As | AssocOp::Colon | AssocOp::DotDot | AssocOp::DotDotEq => { + AssocOp::As | AssocOp::DotDot | AssocOp::DotDotEq => { self.span_bug(span, "AssocOp should have been handled by special case") } }; @@ -373,9 +379,7 @@ impl<'a> Parser<'a> { break; } } - if last_type_ascription_set { - self.last_type_ascription = None; - } + Ok(lhs) } @@ -615,7 +619,9 @@ impl<'a> Parser<'a> { token::Ident(..) if this.may_recover() && this.is_mistaken_not_ident_negation() => { make_it!(this, attrs, |this, _| this.recover_not_expr(lo)) } - _ => return this.parse_expr_dot_or_call(Some(attrs)), + _ => { + return this.parse_expr_dot_or_call(Some(attrs)); + } } } @@ -743,7 +749,7 @@ impl<'a> Parser<'a> { ( // `foo: ` ExprKind::Path(None, ast::Path { segments, .. }), - TokenKind::Ident(kw::For | kw::Loop | kw::While, false), + token::Ident(kw::For | kw::Loop | kw::While, false), ) if segments.len() == 1 => { let snapshot = self.create_snapshot_for_diagnostic(); let label = Label { @@ -838,21 +844,19 @@ impl<'a> Parser<'a> { &mut self, cast_expr: P<Expr>, ) -> PResult<'a, P<Expr>> { + if let ExprKind::Type(_, _) = cast_expr.kind { + panic!("ExprKind::Type must not be parsed"); + } + let span = cast_expr.span; - let (cast_kind, maybe_ascription_span) = - if let ExprKind::Type(ascripted_expr, _) = &cast_expr.kind { - ("type ascription", Some(ascripted_expr.span.shrink_to_hi().with_hi(span.hi()))) - } else { - ("cast", None) - }; let with_postfix = self.parse_expr_dot_or_call_with_(cast_expr, span)?; // Check if an illegal postfix operator has been added after the cast. // If the resulting expression is not a cast, it is an illegal postfix operator. - if !matches!(with_postfix.kind, ExprKind::Cast(_, _) | ExprKind::Type(_, _)) { + if !matches!(with_postfix.kind, ExprKind::Cast(_, _)) { let msg = format!( - "{cast_kind} cannot be followed by {}", + "cast cannot be followed by {}", match with_postfix.kind { ExprKind::Index(_, _) => "indexing", ExprKind::Try(_) => "`?`", @@ -878,44 +882,13 @@ impl<'a> Parser<'a> { ); }; - // If type ascription is "likely an error", the user will already be getting a useful - // help message, and doesn't need a second. - if self.last_type_ascription.map_or(false, |last_ascription| last_ascription.1) { - self.maybe_annotate_with_ascription(&mut err, false); - } else if let Some(ascription_span) = maybe_ascription_span { - let is_nightly = self.sess.unstable_features.is_nightly_build(); - if is_nightly { - suggest_parens(&mut err); - } - err.span_suggestion( - ascription_span, - &format!( - "{}remove the type ascription", - if is_nightly { "alternatively, " } else { "" } - ), - "", - if is_nightly { - Applicability::MaybeIncorrect - } else { - Applicability::MachineApplicable - }, - ); - } else { - suggest_parens(&mut err); - } + suggest_parens(&mut err); + err.emit(); }; Ok(with_postfix) } - fn parse_assoc_op_ascribe(&mut self, lhs: P<Expr>, lhs_span: Span) -> PResult<'a, P<Expr>> { - let maybe_path = self.could_ascription_be_path(&lhs.kind); - self.last_type_ascription = Some((self.prev_token.span, maybe_path)); - let lhs = self.parse_assoc_op_cast(lhs, lhs_span, ExprKind::Type)?; - self.sess.gated_spans.gate(sym::type_ascription, lhs.span); - Ok(lhs) - } - /// Parse `& mut? <expr>` or `& raw [ const | mut ] <expr>`. fn parse_expr_borrow(&mut self, lo: Span) -> PResult<'a, (Span, ExprKind)> { self.expect_and()?; @@ -1010,7 +983,7 @@ impl<'a> Parser<'a> { }; if has_dot { // expr.f - e = self.parse_expr_dot_suffix(lo, e)?; + e = self.parse_dot_suffix_expr(lo, e)?; continue; } if self.expr_is_complete(&e) { @@ -1024,13 +997,7 @@ impl<'a> Parser<'a> { } } - fn look_ahead_type_ascription_as_field(&mut self) -> bool { - self.look_ahead(1, |t| t.is_ident()) - && self.look_ahead(2, |t| t == &token::Colon) - && self.look_ahead(3, |t| t.can_begin_expr()) - } - - fn parse_expr_dot_suffix(&mut self, lo: Span, base: P<Expr>) -> PResult<'a, P<Expr>> { + fn parse_dot_suffix_expr(&mut self, lo: Span, base: P<Expr>) -> PResult<'a, P<Expr>> { match self.token.uninterpolate().kind { token::Ident(..) => self.parse_dot_suffix(base, lo), token::Literal(token::Lit { kind: token::Integer, symbol, suffix }) => { @@ -1183,9 +1150,7 @@ impl<'a> Parser<'a> { /// Parse a function call expression, `expr(...)`. fn parse_expr_fn_call(&mut self, lo: Span, fun: P<Expr>) -> P<Expr> { - let snapshot = if self.token.kind == token::OpenDelim(Delimiter::Parenthesis) - && self.look_ahead_type_ascription_as_field() - { + let snapshot = if self.token.kind == token::OpenDelim(Delimiter::Parenthesis) { Some((self.create_snapshot_for_diagnostic(), fun.kind.clone())) } else { None @@ -1216,7 +1181,6 @@ impl<'a> Parser<'a> { if !self.may_recover() { return None; } - match (seq.as_mut(), snapshot) { (Err(err), Some((mut snapshot, ExprKind::Path(None, path)))) => { snapshot.bump(); // `(` @@ -1260,9 +1224,7 @@ impl<'a> Parser<'a> { return Some(self.mk_expr_err(span)); } Ok(_) => {} - Err(mut err) => { - err.emit(); - } + Err(err) => err.cancel(), } } _ => {} @@ -1516,7 +1478,6 @@ impl<'a> Parser<'a> { let mac = P(MacCall { path, args: self.parse_delim_args()?, - prior_type_ascription: self.last_type_ascription, }); (lo.to(self.prev_token.span), ExprKind::MacCall(mac)) } else if self.check(&token::OpenDelim(Delimiter::Brace)) @@ -1535,7 +1496,7 @@ impl<'a> Parser<'a> { } /// Parse `'label: $expr`. The label is already parsed. - fn parse_expr_labeled( + pub(super) fn parse_expr_labeled( &mut self, label_: Label, mut consume_colon: bool, @@ -3013,6 +2974,11 @@ impl<'a> Parser<'a> { } else { e.span_label(pth.span, "while parsing this struct"); } + + if !recover { + return Err(e); + } + e.emit(); // If the next token is a comma, then try to parse @@ -3024,6 +2990,7 @@ impl<'a> Parser<'a> { break; } } + None } }; diff --git a/compiler/rustc_parse/src/parser/item.rs b/compiler/rustc_parse/src/parser/item.rs index 9e003bfc097..64ff7f1fb2c 100644 --- a/compiler/rustc_parse/src/parser/item.rs +++ b/compiler/rustc_parse/src/parser/item.rs @@ -443,7 +443,7 @@ impl<'a> Parser<'a> { Ok(args) => { self.eat_semi_for_macro_if_needed(&args); self.complain_if_pub_macro(vis, false); - Ok(MacCall { path, args, prior_type_ascription: self.last_type_ascription }) + Ok(MacCall { path, args }) } Err(mut err) => { diff --git a/compiler/rustc_parse/src/parser/mod.rs b/compiler/rustc_parse/src/parser/mod.rs index 1c34e491f21..93a01fafa10 100644 --- a/compiler/rustc_parse/src/parser/mod.rs +++ b/compiler/rustc_parse/src/parser/mod.rs @@ -148,9 +148,6 @@ pub struct Parser<'a> { max_angle_bracket_count: u32, last_unexpected_token_span: Option<Span>, - /// Span pointing at the `:` for the last type ascription the parser has seen, and whether it - /// looked like it could have been a mistyped path or literal `Option:Some(42)`). - pub last_type_ascription: Option<(Span, bool /* likely path typo */)>, /// If present, this `Parser` is not parsing Rust code but rather a macro call. subparser_name: Option<&'static str>, capture_state: CaptureState, @@ -165,7 +162,7 @@ pub struct Parser<'a> { // This type is used a lot, e.g. it's cloned when matching many declarative macro rules with nonterminals. Make sure // it doesn't unintentionally get bigger. #[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))] -rustc_data_structures::static_assert_size!(Parser<'_>, 288); +rustc_data_structures::static_assert_size!(Parser<'_>, 320); /// Stores span information about a closure. #[derive(Clone)] @@ -470,7 +467,6 @@ impl<'a> Parser<'a> { unmatched_angle_bracket_count: 0, max_angle_bracket_count: 0, last_unexpected_token_span: None, - last_type_ascription: None, subparser_name, capture_state: CaptureState { capturing: Capturing::No, @@ -832,10 +828,11 @@ impl<'a> Parser<'a> { } fn expect_any_with_type(&mut self, kets: &[&TokenKind], expect: TokenExpectType) -> bool { - kets.iter().any(|k| match expect { + let res = kets.iter().any(|k| match expect { TokenExpectType::Expect => self.check(k), TokenExpectType::NoExpect => self.token == **k, - }) + }); + res } fn parse_seq_to_before_tokens<T>( @@ -941,10 +938,14 @@ impl<'a> Parser<'a> { // propagate the help message from sub error 'e' to main error 'expect_err; expect_err.children.push(xx.clone()); } - expect_err.emit(); - e.cancel(); - break; + if self.token == token::Colon { + // we will try to recover in `maybe_recover_struct_lit_bad_delims` + return Err(expect_err); + } else { + expect_err.emit(); + break; + } } } } @@ -959,7 +960,6 @@ impl<'a> Parser<'a> { let t = f(self)?; v.push(t); } - Ok((v, trailing, recovered)) } @@ -1045,6 +1045,7 @@ impl<'a> Parser<'a> { f: impl FnMut(&mut Parser<'a>) -> PResult<'a, T>, ) -> PResult<'a, (ThinVec<T>, bool /* trailing */)> { let (val, trailing, recovered) = self.parse_seq_to_before_end(ket, sep, f)?; + if !recovered { self.eat(ket); } diff --git a/compiler/rustc_parse/src/parser/pat.rs b/compiler/rustc_parse/src/parser/pat.rs index f2422fe307c..3c4b2977af9 100644 --- a/compiler/rustc_parse/src/parser/pat.rs +++ b/compiler/rustc_parse/src/parser/pat.rs @@ -406,11 +406,11 @@ impl<'a> Parser<'a> { // Parse pattern starting with a path let (qself, path) = if self.eat_lt() { // Parse a qualified path - let (qself, path) = self.parse_qpath(PathStyle::Expr)?; + let (qself, path) = self.parse_qpath(PathStyle::Pat)?; (Some(qself), path) } else { // Parse an unqualified path - (None, self.parse_path(PathStyle::Expr)?) + (None, self.parse_path(PathStyle::Pat)?) }; let span = lo.to(self.prev_token.span); @@ -666,7 +666,7 @@ impl<'a> Parser<'a> { fn parse_pat_mac_invoc(&mut self, path: Path) -> PResult<'a, PatKind> { self.bump(); let args = self.parse_delim_args()?; - let mac = P(MacCall { path, args, prior_type_ascription: self.last_type_ascription }); + let mac = P(MacCall { path, args }); Ok(PatKind::MacCall(mac)) } @@ -789,11 +789,11 @@ impl<'a> Parser<'a> { let lo = self.token.span; let (qself, path) = if self.eat_lt() { // Parse a qualified path - let (qself, path) = self.parse_qpath(PathStyle::Expr)?; + let (qself, path) = self.parse_qpath(PathStyle::Pat)?; (Some(qself), path) } else { // Parse an unqualified path - (None, self.parse_path(PathStyle::Expr)?) + (None, self.parse_path(PathStyle::Pat)?) }; let hi = self.prev_token.span; Ok(self.mk_expr(lo.to(hi), ExprKind::Path(qself, path))) diff --git a/compiler/rustc_parse/src/parser/path.rs b/compiler/rustc_parse/src/parser/path.rs index ae73760bd8c..323588c4ff5 100644 --- a/compiler/rustc_parse/src/parser/path.rs +++ b/compiler/rustc_parse/src/parser/path.rs @@ -1,5 +1,6 @@ use super::ty::{AllowPlus, RecoverQPath, RecoverReturnSign}; use super::{Parser, Restrictions, TokenType}; +use crate::errors::PathSingleColon; use crate::{errors, maybe_whole}; use rustc_ast::ptr::P; use rustc_ast::token::{self, Delimiter, Token, TokenKind}; @@ -8,7 +9,7 @@ use rustc_ast::{ AssocConstraintKind, BlockCheckMode, GenericArg, GenericArgs, Generics, ParenthesizedArgs, Path, PathSegment, QSelf, }; -use rustc_errors::{Applicability, PResult}; +use rustc_errors::{pluralize, Applicability, IntoDiagnostic, PResult}; use rustc_span::source_map::{BytePos, Span}; use rustc_span::symbol::{kw, sym, Ident}; use std::mem; @@ -16,7 +17,7 @@ use thin_vec::ThinVec; use tracing::debug; /// Specifies how to parse a path. -#[derive(Copy, Clone, PartialEq)] +#[derive(Copy, Clone, PartialEq, Debug)] pub enum PathStyle { /// In some contexts, notably in expressions, paths with generic arguments are ambiguous /// with something else. For example, in expressions `segment < ....` can be interpreted @@ -24,7 +25,19 @@ pub enum PathStyle { /// In all such contexts the non-path interpretation is preferred by default for practical /// reasons, but the path interpretation can be forced by the disambiguator `::`, e.g. /// `x<y>` - comparisons, `x::<y>` - unambiguously a path. + /// + /// Also, a path may never be followed by a `:`. This means that we can eagerly recover if + /// we encounter it. Expr, + /// The same as `Expr`, but may be followed by a `:`. + /// For example, this code: + /// ```rust + /// struct S; + /// + /// let S: S; + /// // ^ Followed by a `:` + /// ``` + Pat, /// In other contexts, notably in types, no ambiguity exists and paths can be written /// without the disambiguator, e.g., `x<y>` - unambiguously a path. /// Paths with disambiguators are still accepted, `x::<Y>` - unambiguously a path too. @@ -38,6 +51,12 @@ pub enum PathStyle { Mod, } +impl PathStyle { + fn has_generic_ambiguity(&self) -> bool { + matches!(self, Self::Expr | Self::Pat) + } +} + impl<'a> Parser<'a> { /// Parses a qualified path. /// Assumes that the leading `<` has been parsed already. @@ -183,7 +202,9 @@ impl<'a> Parser<'a> { segments.push(PathSegment::path_root(lo.shrink_to_lo().with_ctxt(mod_sep_ctxt))); } self.parse_path_segments(&mut segments, style, ty_generics)?; - + if segments.len() > 1 { + //panic!("debug now ..."); + } Ok(Path { segments, span: lo.to(self.prev_token.span), tokens: None }) } @@ -195,7 +216,7 @@ impl<'a> Parser<'a> { ) -> PResult<'a, ()> { loop { let segment = self.parse_path_segment(style, ty_generics)?; - if style == PathStyle::Expr { + if style.has_generic_ambiguity() { // In order to check for trailing angle brackets, we must have finished // recursing (`parse_path_segment` can indirectly call this function), // that is, the next token must be the highlighted part of the below example: @@ -217,6 +238,29 @@ impl<'a> Parser<'a> { segments.push(segment); if self.is_import_coupler() || !self.eat(&token::ModSep) { + if style == PathStyle::Expr + && self.may_recover() + && self.token == token::Colon + && self.look_ahead(1, |token| token.is_ident() && !token.is_reserved_ident()) + { + // Emit a special error message for `a::b:c` to help users + // otherwise, `a: c` might have meant to introduce a new binding + if self.token.span.lo() == self.prev_token.span.hi() + && self.look_ahead(1, |token| self.token.span.hi() == token.span.lo()) + { + self.bump(); // bump past the colon + self.sess.emit_err(PathSingleColon { + span: self.prev_token.span, + type_ascription: self + .sess + .unstable_features + .is_nightly_build() + .then_some(()), + }); + } + continue; + } + return Ok(()); } } @@ -270,8 +314,25 @@ impl<'a> Parser<'a> { ty_generics, )?; self.expect_gt().map_err(|mut err| { + // Try to recover a `:` into a `::` + if self.token == token::Colon + && self.look_ahead(1, |token| { + token.is_ident() && !token.is_reserved_ident() + }) + { + err.cancel(); + err = PathSingleColon { + span: self.token.span, + type_ascription: self + .sess + .unstable_features + .is_nightly_build() + .then_some(()), + } + .into_diagnostic(self.diagnostic()); + } // Attempt to find places where a missing `>` might belong. - if let Some(arg) = args + else if let Some(arg) = args .iter() .rev() .find(|arg| !matches!(arg, AngleBracketedArg::Constraint(_))) @@ -679,6 +740,7 @@ impl<'a> Parser<'a> { &mut self, ty_generics: Option<&Generics>, ) -> PResult<'a, Option<GenericArg>> { + debug!("pain"); let start = self.token.span; let arg = if self.check_lifetime() && self.look_ahead(1, |t| !t.is_like_plus()) { // Parse lifetime argument. @@ -687,6 +749,7 @@ impl<'a> Parser<'a> { // Parse const argument. GenericArg::Const(self.parse_const_arg()?) } else if self.check_type() { + debug!("type"); // Parse type argument. // Proactively create a parser snapshot enabling us to rewind and try to reparse the diff --git a/compiler/rustc_parse/src/parser/stmt.rs b/compiler/rustc_parse/src/parser/stmt.rs index fbe5b88c49e..8e8788beeba 100644 --- a/compiler/rustc_parse/src/parser/stmt.rs +++ b/compiler/rustc_parse/src/parser/stmt.rs @@ -10,6 +10,8 @@ use super::{ use crate::errors; use crate::maybe_whole; +use crate::errors::MalformedLoopLabel; +use ast::Label; use rustc_ast as ast; use rustc_ast::ptr::P; use rustc_ast::token::{self, Delimiter, TokenKind}; @@ -19,7 +21,8 @@ use rustc_ast::{Block, BlockCheckMode, Expr, ExprKind, HasAttrs, Local, Stmt}; use rustc_ast::{StmtKind, DUMMY_NODE_ID}; use rustc_errors::{Applicability, DiagnosticBuilder, ErrorGuaranteed, PResult}; use rustc_span::source_map::{BytePos, Span}; -use rustc_span::symbol::{kw, sym}; +use rustc_span::symbol::{kw, sym, Ident}; + use std::mem; use thin_vec::{thin_vec, ThinVec}; @@ -186,7 +189,7 @@ impl<'a> Parser<'a> { _ => MacStmtStyle::NoBraces, }; - let mac = P(MacCall { path, args, prior_type_ascription: self.last_type_ascription }); + let mac = P(MacCall { path, args }); let kind = if (style == MacStmtStyle::Braces && self.token != token::Dot @@ -546,10 +549,36 @@ impl<'a> Parser<'a> { } let stmt = match self.parse_full_stmt(recover) { Err(mut err) if recover.yes() => { - self.maybe_annotate_with_ascription(&mut err, false); if let Some(ref mut snapshot) = snapshot { snapshot.recover_diff_marker(); } + if self.token == token::Colon { + // if next token is following a colon, it's likely a path + // and we can suggest a path separator + let ident_span = self.prev_token.span; + self.bump(); + if self.token.span.lo() == self.prev_token.span.hi() { + err.span_suggestion_verbose( + self.prev_token.span, + "maybe write a path separator here", + "::", + Applicability::MaybeIncorrect, + ); + } + if self.look_ahead(1, |token| token == &token::Eq) { + err.span_suggestion_verbose( + ident_span.shrink_to_lo(), + "you might have meant to introduce a new binding", + "let ", + Applicability::MaybeIncorrect, + ); + } + if self.sess.unstable_features.is_nightly_build() { + // FIXME(Nilstrieb): Remove this again after a few months. + err.note("type ascription syntax has been removed, see issue #101728 <https://github.com/rust-lang/rust/issues/101728>"); + } + } + err.emit(); self.recover_stmt_(SemiColonMode::Ignore, BlockMode::Ignore); Some(self.mk_stmt_err(self.token.span)) @@ -580,19 +609,25 @@ impl<'a> Parser<'a> { }; let mut eat_semi = true; + let mut add_semi_to_stmt = false; + match &mut stmt.kind { // Expression without semicolon. StmtKind::Expr(expr) if self.token != token::Eof && classify::expr_requires_semi_to_be_stmt(expr) => { // Just check for errors and recover; do not eat semicolon yet. // `expect_one_of` returns PResult<'a, bool /* recovered */> - let replace_with_err = - match self.expect_one_of(&[], &[token::Semi, token::CloseDelim(Delimiter::Brace)]) { + + let expect_result = self.expect_one_of(&[], &[token::Semi, token::CloseDelim(Delimiter::Brace)]); + + let replace_with_err = 'break_recover: { + match expect_result { // Recover from parser, skip type error to avoid extra errors. - Ok(true) => true, - Err(mut e) => { - if let TokenKind::DocComment(..) = self.token.kind && - let Ok(snippet) = self.span_to_snippet(self.token.span) { + Ok(true) => true, + Err(mut e) => { + if let TokenKind::DocComment(..) = self.token.kind + && let Ok(snippet) = self.span_to_snippet(self.token.span) + { let sp = self.token.span; let marker = &snippet[..3]; let (comment_marker, doc_comment_marker) = marker.split_at(2); @@ -606,21 +641,72 @@ impl<'a> Parser<'a> { format!("{} {}", comment_marker, doc_comment_marker), Applicability::MaybeIncorrect, ); - } + } + + if self.recover_colon_as_semi() { + // recover_colon_as_semi has already emitted a nicer error. + e.cancel(); + add_semi_to_stmt = true; + eat_semi = false; + + break 'break_recover false; + } + + match &expr.kind { + ExprKind::Path(None, ast::Path { segments, .. }) if segments.len() == 1 => { + if self.token == token::Colon + && self.look_ahead(1, |token| { + token.is_whole_block() || matches!( + token.kind, + token::Ident(kw::For | kw::Loop | kw::While, false) + | token::OpenDelim(Delimiter::Brace) + ) + }) + { + let snapshot = self.create_snapshot_for_diagnostic(); + let label = Label { + ident: Ident::from_str_and_span( + &format!("'{}", segments[0].ident), + segments[0].ident.span, + ), + }; + match self.parse_expr_labeled(label, false) { + Ok(labeled_expr) => { + e.cancel(); + self.sess.emit_err(MalformedLoopLabel { + span: label.ident.span, + correct_label: label.ident, + }); + *expr = labeled_expr; + break 'break_recover false; + } + Err(err) => { + err.cancel(); + self.restore_snapshot(snapshot); + } + } + } + } + _ => {} + } - if let Err(mut e) = - self.check_mistyped_turbofish_with_multiple_type_params(e, expr) - { - if recover.no() { - return Err(e); + if let Err(mut e) = + self.check_mistyped_turbofish_with_multiple_type_params(e, expr) + { + if recover.no() { + return Err(e); + } + e.emit(); + self.recover_stmt(); } - e.emit(); - self.recover_stmt(); + + true + } - true + Ok(false) => false } - _ => false }; + if replace_with_err { // We already emitted an error, so don't emit another type error let sp = expr.span.to(self.prev_token.span); @@ -643,9 +729,10 @@ impl<'a> Parser<'a> { StmtKind::Empty | StmtKind::Item(_) | StmtKind::Local(_) | StmtKind::Semi(_) => eat_semi = false, } - if eat_semi && self.eat(&token::Semi) { + if add_semi_to_stmt || (eat_semi && self.eat(&token::Semi)) { stmt = stmt.add_trailing_semicolon(); } + stmt.span = stmt.span.to(self.prev_token.span); Ok(Some(stmt)) } diff --git a/compiler/rustc_parse/src/parser/ty.rs b/compiler/rustc_parse/src/parser/ty.rs index 3ceb3a2bef1..37c441fbecb 100644 --- a/compiler/rustc_parse/src/parser/ty.rs +++ b/compiler/rustc_parse/src/parser/ty.rs @@ -317,7 +317,6 @@ impl<'a> Parser<'a> { let msg = format!("expected type, found {}", super::token_descr(&self.token)); 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); }; @@ -651,11 +650,7 @@ 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) |