From e81a5c65d9b254e625b96dfc756f1695ee1824ed Mon Sep 17 00:00:00 2001 From: clubby789 Date: Thu, 26 Oct 2023 11:35:11 +0000 Subject: Recover ternary expression as error --- compiler/rustc_parse/src/parser/diagnostics.rs | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) (limited to 'compiler/rustc_parse') diff --git a/compiler/rustc_parse/src/parser/diagnostics.rs b/compiler/rustc_parse/src/parser/diagnostics.rs index 64db7d9809e..7b5bb319ed8 100644 --- a/compiler/rustc_parse/src/parser/diagnostics.rs +++ b/compiler/rustc_parse/src/parser/diagnostics.rs @@ -504,8 +504,10 @@ impl<'a> Parser<'a> { // Special-case "expected `;`" errors if expected.contains(&TokenType::Token(token::Semi)) { - if self.prev_token == token::Question && self.maybe_recover_from_ternary_operator() { - return Ok(true); + // If the user is trying to write a ternary expression, recover it and + // return an Err to prevent a cascade of irrelevant diagnostics + if self.prev_token == token::Question && let Err(e) = self.maybe_recover_from_ternary_operator() { + return Err(e); } if self.token.span == DUMMY_SP || self.prev_token.span == DUMMY_SP { @@ -1428,10 +1430,10 @@ impl<'a> Parser<'a> { /// Rust has no ternary operator (`cond ? then : else`). Parse it and try /// to recover from it if `then` and `else` are valid expressions. Returns - /// whether it was a ternary operator. - pub(super) fn maybe_recover_from_ternary_operator(&mut self) -> bool { + /// an err if this appears to be a ternary expression. + pub(super) fn maybe_recover_from_ternary_operator(&mut self) -> PResult<'a, ()> { if self.prev_token != token::Question { - return false; + return PResult::Ok(()); } let lo = self.prev_token.span.lo(); @@ -1449,8 +1451,9 @@ impl<'a> Parser<'a> { if self.eat_noexpect(&token::Colon) { match self.parse_expr() { Ok(_) => { - self.sess.emit_err(TernaryOperator { span: self.token.span.with_lo(lo) }); - return true; + return Err(self + .sess + .create_err(TernaryOperator { span: self.token.span.with_lo(lo) })); } Err(err) => { err.cancel(); @@ -1459,8 +1462,7 @@ impl<'a> Parser<'a> { } } self.restore_snapshot(snapshot); - - false + Ok(()) } pub(super) fn maybe_recover_from_bad_type_plus(&mut self, ty: &Ty) -> PResult<'a, ()> { -- cgit 1.4.1-3-g733a5