diff --git a/compiler/rustc_parse/src/parser/expr.rs b/compiler/rustc_parse/src/parser/expr.rs index 9fad954adda..e0c70884fee 100644 --- a/compiler/rustc_parse/src/parser/expr.rs +++ b/compiler/rustc_parse/src/parser/expr.rs @@ -39,36 +39,6 @@ use rustc_span::{BytePos, ErrorGuaranteed, Pos, Span}; use thin_vec::{thin_vec, ThinVec}; use tracing::instrument; -/// Possibly accepts an `token::Interpolated` expression (a pre-parsed expression -/// dropped into the token stream, which happens while parsing the result of -/// macro expansion). Placement of these is not as complex as I feared it would -/// be. The important thing is to make sure that lookahead doesn't balk at -/// `token::Interpolated` tokens. -macro_rules! maybe_whole_expr { - ($p:expr) => { - if let token::Interpolated(nt) = &$p.token.kind { - match &**nt { - token::NtExpr(e) | token::NtLiteral(e) => { - let e = e.clone(); - $p.bump(); - return Ok(e); - } - token::NtPath(path) => { - let path = (**path).clone(); - $p.bump(); - return Ok($p.mk_expr($p.prev_token.span, ExprKind::Path(None, path))); - } - token::NtBlock(block) => { - let block = block.clone(); - $p.bump(); - return Ok($p.mk_expr($p.prev_token.span, ExprKind::Block(block, None))); - } - _ => {} - }; - } - }; -} - #[derive(Debug)] pub(super) enum LhsExpr { // Already parsed just the outer attributes. @@ -1421,7 +1391,27 @@ impl<'a> Parser<'a> { /// correctly if called from `parse_dot_or_call_expr()`. fn parse_expr_bottom(&mut self) -> PResult<'a, P> { maybe_recover_from_interpolated_ty_qpath!(self, true); - maybe_whole_expr!(self); + + if let token::Interpolated(nt) = &self.token.kind { + match &**nt { + token::NtExpr(e) | token::NtLiteral(e) => { + let e = e.clone(); + self.bump(); + return Ok(e); + } + token::NtPath(path) => { + let path = (**path).clone(); + self.bump(); + return Ok(self.mk_expr(self.prev_token.span, ExprKind::Path(None, path))); + } + token::NtBlock(block) => { + let block = block.clone(); + self.bump(); + return Ok(self.mk_expr(self.prev_token.span, ExprKind::Block(block, None))); + } + _ => {} + }; + } // Outer attributes are already parsed and will be // added to the return value after the fact. @@ -2190,7 +2180,26 @@ impl<'a> Parser<'a> { /// Matches `'-' lit | lit` (cf. `ast_validation::AstValidator::check_expr_within_pat`). /// Keep this in sync with `Token::can_begin_literal_maybe_minus`. pub fn parse_literal_maybe_minus(&mut self) -> PResult<'a, P> { - maybe_whole_expr!(self); + if let token::Interpolated(nt) = &self.token.kind { + match &**nt { + // FIXME(nnethercote) The `NtExpr` case should only match if + // `e` is an `ExprKind::Lit` or an `ExprKind::Unary` containing + // an `UnOp::Neg` and an `ExprKind::Lit`, like how + // `can_begin_literal_maybe_minus` works. But this method has + // been over-accepting for a long time, and to make that change + // here requires also changing some `parse_literal_maybe_minus` + // call sites to accept additional expression kinds. E.g. + // `ExprKind::Path` must be accepted when parsing range + // patterns. That requires some care. So for now, we continue + // being less strict here than we should be. + token::NtExpr(e) | token::NtLiteral(e) => { + let e = e.clone(); + self.bump(); + return Ok(e); + } + _ => {} + }; + } let lo = self.token.span; let minus_present = self.eat(&token::BinOp(token::Minus));