diff options
Diffstat (limited to 'compiler/rustc_parse/src/parser/diagnostics.rs')
| -rw-r--r-- | compiler/rustc_parse/src/parser/diagnostics.rs | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/compiler/rustc_parse/src/parser/diagnostics.rs b/compiler/rustc_parse/src/parser/diagnostics.rs index 4c918c6702e..6596a06afab 100644 --- a/compiler/rustc_parse/src/parser/diagnostics.rs +++ b/compiler/rustc_parse/src/parser/diagnostics.rs @@ -2353,6 +2353,28 @@ impl<'a> Parser<'a> { Err(err) } + /// Try to recover from an unbraced const argument whose first token [could begin a type][ty]. + /// + /// [ty]: token::Token::can_begin_type + pub(crate) fn recover_unbraced_const_arg_that_can_begin_ty( + &mut self, + mut snapshot: SnapshotParser<'a>, + ) -> Option<P<ast::Expr>> { + match snapshot.parse_expr_res(Restrictions::CONST_EXPR, None) { + // Since we don't know the exact reason why we failed to parse the type or the + // expression, employ a simple heuristic to weed out some pathological cases. + Ok(expr) if let token::Comma | token::Gt = snapshot.token.kind => { + self.restore_snapshot(snapshot); + Some(expr) + } + Ok(_) => None, + Err(err) => { + err.cancel(); + None + } + } + } + /// Creates a dummy const argument, and reports that the expression must be enclosed in braces pub fn dummy_const_arg_needs_braces( &self, |