diff options
Diffstat (limited to 'compiler/rustc_parse/src/parser/expr.rs')
| -rw-r--r-- | compiler/rustc_parse/src/parser/expr.rs | 177 |
1 files changed, 104 insertions, 73 deletions
diff --git a/compiler/rustc_parse/src/parser/expr.rs b/compiler/rustc_parse/src/parser/expr.rs index 27de9bd7268..ee712a8e1b5 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); } @@ -301,9 +299,6 @@ impl<'a> Parser<'a> { 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 +359,7 @@ 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 +368,7 @@ impl<'a> Parser<'a> { break; } } - if last_type_ascription_set { - self.last_type_ascription = None; - } + Ok(lhs) } @@ -743,7 +736,7 @@ 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 { @@ -838,33 +831,31 @@ 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(_) => "`?`", ExprKind::Field(_, _) => "a field access", ExprKind::MethodCall(_) => "a method call", ExprKind::Call(_, _) => "a function call", - ExprKind::Await(_) => "`.await`", + ExprKind::Await(_, _) => "`.await`", ExprKind::Err => return Ok(with_postfix), _ => unreachable!("parse_dot_or_call_expr_with_ shouldn't produce this"), } ); - let mut err = self.struct_span_err(span, &msg); + let mut err = self.struct_span_err(span, msg); let suggest_parens = |err: &mut Diagnostic| { let suggestions = vec![ @@ -878,44 +869,13 @@ 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 +970,7 @@ 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 +984,7 @@ 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 +1137,7 @@ 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 +1168,6 @@ 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(); // `(` @@ -1229,6 +1180,10 @@ impl<'a> Parser<'a> { self.restore_snapshot(snapshot); let close_paren = self.prev_token.span; let span = lo.to(close_paren); + // filter shorthand fields + let fields: Vec<_> = + fields.into_iter().filter(|field| !field.is_shorthand).collect(); + if !fields.is_empty() && // `token.kind` should not be compared here. // This is because the `snapshot.token.kind` is treated as the same as @@ -1260,9 +1215,7 @@ impl<'a> Parser<'a> { return Some(self.mk_expr_err(span)); } Ok(_) => {} - Err(mut err) => { - err.emit(); - } + Err(err) => err.cancel(), } } _ => {} @@ -1351,6 +1304,8 @@ impl<'a> Parser<'a> { }) } else if self.check(&token::OpenDelim(Delimiter::Bracket)) { self.parse_expr_array_or_repeat(Delimiter::Bracket) + } else if self.is_builtin() { + self.parse_expr_builtin() } else if self.check_path() { self.parse_expr_path_start() } else if self.check_keyword(kw::Move) @@ -1499,8 +1454,19 @@ impl<'a> Parser<'a> { } fn parse_expr_path_start(&mut self) -> PResult<'a, P<Expr>> { + let maybe_eq_tok = self.prev_token.clone(); let (qself, path) = if self.eat_lt() { - let (qself, path) = self.parse_qpath(PathStyle::Expr)?; + let lt_span = self.prev_token.span; + let (qself, path) = self.parse_qpath(PathStyle::Expr).map_err(|mut err| { + // Suggests using '<=' if there is an error parsing qpath when the previous token + // is an '=' token. Only emits suggestion if the '<' token and '=' token are + // directly adjacent (i.e. '=<') + if maybe_eq_tok.kind == TokenKind::Eq && maybe_eq_tok.span.hi() == lt_span.lo() { + let eq_lt = maybe_eq_tok.span.to(lt_span); + err.span_suggestion(eq_lt, "did you mean", "<=", Applicability::Unspecified); + } + err + })?; (Some(qself), path) } else { (None, self.parse_path(PathStyle::Expr)?) @@ -1516,7 +1482,6 @@ 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 +1500,7 @@ 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, @@ -1807,6 +1772,61 @@ impl<'a> Parser<'a> { self.maybe_recover_from_bad_qpath(expr) } + /// Parse `builtin # ident(args,*)`. + fn parse_expr_builtin(&mut self) -> PResult<'a, P<Expr>> { + self.parse_builtin(|this, lo, ident| { + if ident.name == sym::offset_of { + return Ok(Some(this.parse_expr_offset_of(lo)?)); + } + + Ok(None) + }) + } + + pub(crate) fn parse_builtin<T>( + &mut self, + parse: impl FnOnce(&mut Parser<'a>, Span, Ident) -> PResult<'a, Option<T>>, + ) -> PResult<'a, T> { + let lo = self.token.span; + + self.bump(); // `builtin` + self.bump(); // `#` + + let Some((ident, false)) = self.token.ident() else { + let err = errors::ExpectedBuiltinIdent { span: self.token.span } + .into_diagnostic(&self.sess.span_diagnostic); + return Err(err); + }; + self.sess.gated_spans.gate(sym::builtin_syntax, ident.span); + self.bump(); + + self.expect(&TokenKind::OpenDelim(Delimiter::Parenthesis))?; + let ret = if let Some(res) = parse(self, lo, ident)? { + Ok(res) + } else { + let err = errors::UnknownBuiltinConstruct { span: lo.to(ident.span), name: ident.name } + .into_diagnostic(&self.sess.span_diagnostic); + return Err(err); + }; + self.expect(&TokenKind::CloseDelim(Delimiter::Parenthesis))?; + + ret + } + + pub(crate) fn parse_expr_offset_of(&mut self, lo: Span) -> PResult<'a, P<Expr>> { + let container = self.parse_ty()?; + self.expect(&TokenKind::Comma)?; + + let seq_sep = SeqSep { sep: Some(token::Dot), trailing_sep_allowed: false }; + let (fields, _trailing, _recovered) = self.parse_seq_to_before_end( + &TokenKind::CloseDelim(Delimiter::Parenthesis), + seq_sep, + Parser::parse_field_name, + )?; + let span = lo.to(self.token.span); + Ok(self.mk_expr(span, ExprKind::OffsetOf(container, fields.to_vec().into()))) + } + /// Returns a string literal if the next token is a string literal. /// In case of error returns `Some(lit)` if the next token is a literal with a wrong kind, /// and returns `None` if the next token is not literal at all. @@ -1855,7 +1875,7 @@ impl<'a> Parser<'a> { let token = self.token.clone(); let err = |self_: &Self| { let msg = format!("unexpected token: {}", super::token_descr(&token)); - self_.struct_span_err(token.span, &msg) + self_.struct_span_err(token.span, msg) }; // On an error path, eagerly consider a lifetime to be an unclosed character lit if self.token.is_lifetime() { @@ -1922,6 +1942,7 @@ impl<'a> Parser<'a> { let recovered = self.recover_after_dot(); let token = recovered.as_ref().unwrap_or(&self.token); let span = token.span; + token::Lit::from_token(token).map(|token_lit| { self.bump(); (token_lit, span) @@ -2875,6 +2896,10 @@ impl<'a> Parser<'a> { }) } + pub(crate) fn is_builtin(&self) -> bool { + self.token.is_keyword(kw::Builtin) && self.look_ahead(1, |t| *t == token::Pound) + } + /// Parses a `try {...}` expression (`try` token already eaten). fn parse_try_block(&mut self, span_lo: Span) -> PResult<'a, P<Expr>> { let (attrs, body) = self.parse_inner_attrs_and_block()?; @@ -3013,6 +3038,11 @@ 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 +3054,7 @@ impl<'a> Parser<'a> { break; } } + None } }; @@ -3252,7 +3283,7 @@ impl<'a> Parser<'a> { fn mk_await_expr(&mut self, self_arg: P<Expr>, lo: Span) -> P<Expr> { let span = lo.to(self.prev_token.span); - let await_expr = self.mk_expr(span, ExprKind::Await(self_arg)); + let await_expr = self.mk_expr(span, ExprKind::Await(self_arg, self.prev_token.span)); self.recover_from_await_method_call(); await_expr } |