diff --git a/src/test/ui-fulldeps/pprust-expr-roundtrip.rs b/src/test/ui-fulldeps/pprust-expr-roundtrip.rs index 09f58521e5d..89c17cf4b3a 100644 --- a/src/test/ui-fulldeps/pprust-expr-roundtrip.rs +++ b/src/test/ui-fulldeps/pprust-expr-roundtrip.rs @@ -32,13 +32,15 @@ use syntax::print::pprust; use syntax::ptr::P; -fn parse_expr(ps: &ParseSess, src: &str) -> P { +fn parse_expr(ps: &ParseSess, src: &str) -> Option> { let src_as_string = src.to_string(); - let mut p = parse::new_parser_from_source_str(ps, - FileName::Custom(src_as_string.clone()), - src_as_string); - p.parse_expr().unwrap() + let mut p = parse::new_parser_from_source_str( + ps, + FileName::Custom(src_as_string.clone()), + src_as_string, + ); + p.parse_expr().map_err(|mut e| e.cancel()).ok() } @@ -209,22 +211,23 @@ fn run() { let printed = pprust::expr_to_string(&e); println!("printed: {}", printed); - let mut parsed = parse_expr(&ps, &printed); - - // We want to know if `parsed` is structurally identical to `e`, ignoring trivial - // differences like placement of `Paren`s or the exact ranges of node spans. - // Unfortunately, there is no easy way to make this comparison. Instead, we add `Paren`s - // everywhere we can, then pretty-print. This should give an unambiguous representation of - // each `Expr`, and it bypasses nearly all of the parenthesization logic, so we aren't - // relying on the correctness of the very thing we're testing. - RemoveParens.visit_expr(&mut e); - AddParens.visit_expr(&mut e); - let text1 = pprust::expr_to_string(&e); - RemoveParens.visit_expr(&mut parsed); - AddParens.visit_expr(&mut parsed); - let text2 = pprust::expr_to_string(&parsed); - assert!(text1 == text2, - "exprs are not equal:\n e = {:?}\n parsed = {:?}", - text1, text2); + // Ignore expressions with chained comparisons that fail to parse + if let Some(mut parsed) = parse_expr(&ps, &printed) { + // We want to know if `parsed` is structurally identical to `e`, ignoring trivial + // differences like placement of `Paren`s or the exact ranges of node spans. + // Unfortunately, there is no easy way to make this comparison. Instead, we add `Paren`s + // everywhere we can, then pretty-print. This should give an unambiguous representation + // of each `Expr`, and it bypasses nearly all of the parenthesization logic, so we + // aren't relying on the correctness of the very thing we're testing. + RemoveParens.visit_expr(&mut e); + AddParens.visit_expr(&mut e); + let text1 = pprust::expr_to_string(&e); + RemoveParens.visit_expr(&mut parsed); + AddParens.visit_expr(&mut parsed); + let text2 = pprust::expr_to_string(&parsed); + assert!(text1 == text2, + "exprs are not equal:\n e = {:?}\n parsed = {:?}", + text1, text2); + } }); }