diff options
Diffstat (limited to 'compiler/rustc_parse/src/parser/expr.rs')
| -rw-r--r-- | compiler/rustc_parse/src/parser/expr.rs | 174 |
1 files changed, 99 insertions, 75 deletions
diff --git a/compiler/rustc_parse/src/parser/expr.rs b/compiler/rustc_parse/src/parser/expr.rs index 7a34bc7890c..00947a4c585 100644 --- a/compiler/rustc_parse/src/parser/expr.rs +++ b/compiler/rustc_parse/src/parser/expr.rs @@ -11,12 +11,11 @@ use crate::errors; use crate::maybe_recover_from_interpolated_ty_qpath; use ast::mut_visit::{noop_visit_expr, MutVisitor}; use ast::token::IdentIsRaw; -use ast::{CoroutineKind, ForLoopKind, GenBlockKind, Pat, Path, PathSegment}; +use ast::{CoroutineKind, ForLoopKind, GenBlockKind, MatchKind, Pat, Path, PathSegment}; use core::mem; use core::ops::ControlFlow; use rustc_ast::ptr::P; use rustc_ast::token::{self, Delimiter, Token, TokenKind}; -use rustc_ast::tokenstream::Spacing; use rustc_ast::util::case::Case; use rustc_ast::util::classify; use rustc_ast::util::parser::{prec_let_scrutinee_needs_par, AssocOp, Fixity}; @@ -27,7 +26,7 @@ use rustc_ast::{Arm, BlockCheckMode, Expr, ExprKind, Label, Movability, RangeLim use rustc_ast::{ClosureBinder, MetaItemLit, StmtKind}; use rustc_ast_pretty::pprust; use rustc_data_structures::stack::ensure_sufficient_stack; -use rustc_errors::{AddToDiagnostic, Applicability, Diag, PResult, StashKey}; +use rustc_errors::{Applicability, Diag, PResult, StashKey, Subdiagnostic}; use rustc_lexer::unescape::unescape_char; use rustc_macros::Subdiagnostic; use rustc_session::errors::{report_lit_error, ExprParenthesesNeeded}; @@ -861,6 +860,7 @@ impl<'a> Parser<'a> { ExprKind::MethodCall(_) => "a method call", ExprKind::Call(_, _) => "a function call", ExprKind::Await(_, _) => "`.await`", + ExprKind::Match(_, _, MatchKind::Postfix) => "a postfix match", ExprKind::Err(_) => return Ok(with_postfix), _ => unreachable!("parse_dot_or_call_expr_with_ shouldn't produce this"), } @@ -943,7 +943,10 @@ impl<'a> Parser<'a> { // Stitch the list of outer attributes onto the return value. // A little bit ugly, but the best way given the current code // structure - let res = self.parse_expr_dot_or_call_with_(e0, lo); + let res = ensure_sufficient_stack( + // this expr demonstrates the recursion it guards against + || self.parse_expr_dot_or_call_with_(e0, lo), + ); if attrs.is_empty() { res } else { @@ -996,13 +999,57 @@ impl<'a> Parser<'a> { } pub fn parse_dot_suffix_expr(&mut self, lo: Span, base: P<Expr>) -> PResult<'a, P<Expr>> { + // At this point we've consumed something like `expr.` and `self.token` holds the token + // after the dot. match self.token.uninterpolate().kind { token::Ident(..) => self.parse_dot_suffix(base, lo), token::Literal(token::Lit { kind: token::Integer, symbol, suffix }) => { - Ok(self.parse_expr_tuple_field_access(lo, base, symbol, suffix, None)) + let ident_span = self.token.span; + self.bump(); + Ok(self.mk_expr_tuple_field_access(lo, ident_span, base, symbol, suffix)) } token::Literal(token::Lit { kind: token::Float, symbol, suffix }) => { - Ok(self.parse_expr_tuple_field_access_float(lo, base, symbol, suffix)) + Ok(match self.break_up_float(symbol, self.token.span) { + // 1e2 + DestructuredFloat::Single(sym, _sp) => { + // `foo.1e2`: a single complete dot access, fully consumed. We end up with + // the `1e2` token in `self.prev_token` and the following token in + // `self.token`. + let ident_span = self.token.span; + self.bump(); + self.mk_expr_tuple_field_access(lo, ident_span, base, sym, suffix) + } + // 1. + DestructuredFloat::TrailingDot(sym, ident_span, dot_span) => { + // `foo.1.`: a single complete dot access and the start of another. + // We end up with the `sym` (`1`) token in `self.prev_token` and a dot in + // `self.token`. + assert!(suffix.is_none()); + self.token = Token::new(token::Ident(sym, IdentIsRaw::No), ident_span); + self.bump_with((Token::new(token::Dot, dot_span), self.token_spacing)); + self.mk_expr_tuple_field_access(lo, ident_span, base, sym, None) + } + // 1.2 | 1.2e3 + DestructuredFloat::MiddleDot( + sym1, + ident1_span, + _dot_span, + sym2, + ident2_span, + ) => { + // `foo.1.2` (or `foo.1.2e3`): two complete dot accesses. We end up with + // the `sym2` (`2` or `2e3`) token in `self.prev_token` and the following + // token in `self.token`. + let next_token2 = + Token::new(token::Ident(sym2, IdentIsRaw::No), ident2_span); + self.bump_with((next_token2, self.token_spacing)); + self.bump(); + let base1 = + self.mk_expr_tuple_field_access(lo, ident1_span, base, sym1, None); + self.mk_expr_tuple_field_access(lo, ident2_span, base1, sym2, suffix) + } + DestructuredFloat::Error => base, + }) } _ => { self.error_unexpected_after_dot(); @@ -1116,41 +1163,6 @@ impl<'a> Parser<'a> { } } - fn parse_expr_tuple_field_access_float( - &mut self, - lo: Span, - base: P<Expr>, - float: Symbol, - suffix: Option<Symbol>, - ) -> P<Expr> { - match self.break_up_float(float, self.token.span) { - // 1e2 - DestructuredFloat::Single(sym, _sp) => { - self.parse_expr_tuple_field_access(lo, base, sym, suffix, None) - } - // 1. - DestructuredFloat::TrailingDot(sym, ident_span, dot_span) => { - assert!(suffix.is_none()); - self.token = Token::new(token::Ident(sym, IdentIsRaw::No), ident_span); - let next_token = (Token::new(token::Dot, dot_span), self.token_spacing); - self.parse_expr_tuple_field_access(lo, base, sym, None, Some(next_token)) - } - // 1.2 | 1.2e3 - DestructuredFloat::MiddleDot(symbol1, ident1_span, dot_span, symbol2, ident2_span) => { - self.token = Token::new(token::Ident(symbol1, IdentIsRaw::No), ident1_span); - // This needs to be `Spacing::Alone` to prevent regressions. - // See issue #76399 and PR #76285 for more details - let next_token1 = (Token::new(token::Dot, dot_span), Spacing::Alone); - let base1 = - self.parse_expr_tuple_field_access(lo, base, symbol1, None, Some(next_token1)); - let next_token2 = Token::new(token::Ident(symbol2, IdentIsRaw::No), ident2_span); - self.bump_with((next_token2, self.token_spacing)); // `.` - self.parse_expr_tuple_field_access(lo, base1, symbol2, suffix, None) - } - DestructuredFloat::Error => base, - } - } - /// Parse the field access used in offset_of, matched by `$(e:expr)+`. /// Currently returns a list of idents. However, it should be possible in /// future to also do array indices, which might be arbitrary expressions. @@ -1252,24 +1264,18 @@ impl<'a> Parser<'a> { Ok(fields.into_iter().collect()) } - fn parse_expr_tuple_field_access( + fn mk_expr_tuple_field_access( &mut self, lo: Span, + ident_span: Span, base: P<Expr>, field: Symbol, suffix: Option<Symbol>, - next_token: Option<(Token, Spacing)>, ) -> P<Expr> { - match next_token { - Some(next_token) => self.bump_with(next_token), - None => self.bump(), - } - let span = self.prev_token.span; - let field = ExprKind::Field(base, Ident::new(field, span)); if let Some(suffix) = suffix { - self.expect_no_tuple_index_suffix(span, suffix); + self.expect_no_tuple_index_suffix(ident_span, suffix); } - self.mk_expr(lo.to(span), field) + self.mk_expr(lo.to(ident_span), ExprKind::Field(base, Ident::new(field, ident_span))) } /// Parse a function call expression, `expr(...)`. @@ -1376,6 +1382,13 @@ impl<'a> Parser<'a> { return Ok(self.mk_await_expr(self_arg, lo)); } + // Post-fix match + if self.eat_keyword(kw::Match) { + let match_span = self.prev_token.span; + self.psess.gated_spans.gate(sym::postfix_match, match_span); + return self.parse_match_block(lo, match_span, self_arg, MatchKind::Postfix); + } + let fn_span_lo = self.token.span; let mut seg = self.parse_path_segment(PathStyle::Expr, None)?; self.check_trailing_angle_brackets(&seg, &[&token::OpenDelim(Delimiter::Parenthesis)]); @@ -1936,11 +1949,11 @@ impl<'a> Parser<'a> { /// 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) + Ok(match ident.name { + sym::offset_of => Some(this.parse_expr_offset_of(lo)?), + sym::type_ascribe => Some(this.parse_expr_type_ascribe(lo)?), + _ => None, + }) }) } @@ -1975,6 +1988,7 @@ impl<'a> Parser<'a> { ret } + /// Built-in macro for `offset_of!` expressions. pub(crate) fn parse_expr_offset_of(&mut self, lo: Span) -> PResult<'a, P<Expr>> { let container = self.parse_ty()?; self.expect(&TokenKind::Comma)?; @@ -2004,6 +2018,15 @@ impl<'a> Parser<'a> { Ok(self.mk_expr(span, ExprKind::OffsetOf(container, fields))) } + /// Built-in macro for type ascription expressions. + pub(crate) fn parse_expr_type_ascribe(&mut self, lo: Span) -> PResult<'a, P<Expr>> { + let expr = self.parse_expr()?; + self.expect(&token::Comma)?; + let ty = self.parse_ty()?; + let span = lo.to(self.token.span); + Ok(self.mk_expr(span, ExprKind::Type(expr, ty))) + } + /// 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. @@ -2040,16 +2063,6 @@ impl<'a> Parser<'a> { &mut self, mk_lit_char: impl FnOnce(Symbol, Span) -> L, ) -> PResult<'a, L> { - if let token::Interpolated(nt) = &self.token.kind - && let token::NtExpr(e) | token::NtLiteral(e) = &nt.0 - && matches!(e.kind, ExprKind::Err(_)) - { - let mut err = self - .dcx() - .create_err(errors::InvalidInterpolatedExpression { span: self.token.span }); - err.downgrade_to_delayed_bug(); - return Err(err); - } let token = self.token.clone(); let err = |self_: &Self| { let msg = format!("unexpected token: {}", super::token_descr(&token)); @@ -2756,7 +2769,7 @@ impl<'a> Parser<'a> { }; return if self.token.kind == token::CloseDelim(Delimiter::Parenthesis) { // We know for sure we have seen `for ($SOMETHING in $EXPR)`, so we recover the - // parser state and emit a targetted suggestion. + // parser state and emit a targeted suggestion. let span = vec![start_span, self.token.span]; let right = self.prev_token.span.between(self.look_ahead(1, |t| t.span)); self.bump(); // ) @@ -2891,8 +2904,20 @@ impl<'a> Parser<'a> { /// Parses a `match ... { ... }` expression (`match` token already eaten). fn parse_expr_match(&mut self) -> PResult<'a, P<Expr>> { let match_span = self.prev_token.span; - let lo = self.prev_token.span; let scrutinee = self.parse_expr_res(Restrictions::NO_STRUCT_LITERAL, None)?; + + self.parse_match_block(match_span, match_span, scrutinee, MatchKind::Prefix) + } + + /// Parses the block of a `match expr { ... }` or a `expr.match { ... }` + /// expression. This is after the match token and scrutinee are eaten + fn parse_match_block( + &mut self, + lo: Span, + match_span: Span, + scrutinee: P<Expr>, + match_kind: MatchKind, + ) -> PResult<'a, P<Expr>> { if let Err(mut e) = self.expect(&token::OpenDelim(Delimiter::Brace)) { if self.token == token::Semi { e.span_suggestion_short( @@ -2935,7 +2960,7 @@ impl<'a> Parser<'a> { }); return Ok(self.mk_expr_with_attrs( span, - ExprKind::Match(scrutinee, arms), + ExprKind::Match(scrutinee, arms, match_kind), attrs, )); } @@ -2943,7 +2968,7 @@ impl<'a> Parser<'a> { } let hi = self.token.span; self.bump(); - Ok(self.mk_expr_with_attrs(lo.to(hi), ExprKind::Match(scrutinee, arms), attrs)) + Ok(self.mk_expr_with_attrs(lo.to(hi), ExprKind::Match(scrutinee, arms, match_kind), attrs)) } /// Attempt to recover from match arm body with statements and no surrounding braces. @@ -3451,8 +3476,8 @@ impl<'a> Parser<'a> { let in_if_guard = self.restrictions.contains(Restrictions::IN_IF_GUARD); let async_block_err = |e: &mut Diag<'_>, span: Span| { - errors::AsyncBlockIn2015 { span }.add_to_diagnostic(e); - errors::HelpUseLatestEdition::new().add_to_diagnostic(e); + errors::AsyncBlockIn2015 { span }.add_to_diag(e); + errors::HelpUseLatestEdition::new().add_to_diag(e); }; while self.token != token::CloseDelim(close_delim) { @@ -3560,8 +3585,7 @@ impl<'a> Parser<'a> { match self.expect_one_of(&[token::Comma], &[token::CloseDelim(close_delim)]) { Ok(_) => { - if let Some(f) = - parsed_field.or_else(|guar| field_ident(self, guar).ok_or(guar)).ok() + if let Ok(f) = parsed_field.or_else(|guar| field_ident(self, guar).ok_or(guar)) { // Only include the field if there's no parse error for the field name. fields.push(f); @@ -3952,7 +3976,7 @@ impl MutVisitor for CondChecker<'_> { | ExprKind::While(_, _, _) | ExprKind::ForLoop { .. } | ExprKind::Loop(_, _, _) - | ExprKind::Match(_, _) + | ExprKind::Match(_, _, _) | ExprKind::Closure(_) | ExprKind::Block(_, _) | ExprKind::Gen(_, _, _) |