From 0e19fb92e1eb7f91aa5570b2ac782c9a42a6e329 Mon Sep 17 00:00:00 2001 From: Yiming Lei Date: Wed, 30 Nov 2022 12:01:00 -0800 Subject: While parsing enum variant, the error message always disappear Because the error message that emit out is from main error of parser The information of enum variant disappears while parsing enum variant with error We only check the syntax of expecting token, i.e, in case #103869 It will error it without telling the message that this error is from pasring enum variant. Propagate the sub-error from parsing enum variant to the main error of parser by chaining it with map_err Check the sub-error before emitting the main error of parser and attach it. Fix #103869 --- compiler/rustc_parse/src/parser/item.rs | 5 ++++- compiler/rustc_parse/src/parser/mod.rs | 4 ++++ 2 files changed, 8 insertions(+), 1 deletion(-) (limited to 'compiler/rustc_parse/src/parser') diff --git a/compiler/rustc_parse/src/parser/item.rs b/compiler/rustc_parse/src/parser/item.rs index 767fb9378be..7ce89b5c359 100644 --- a/compiler/rustc_parse/src/parser/item.rs +++ b/compiler/rustc_parse/src/parser/item.rs @@ -1414,7 +1414,10 @@ impl<'a> Parser<'a> { Ok((Some(vr), TrailingToken::MaybeComma)) }, - ) + ).map_err(|mut err|{ + err.help("enum variants can be `Variant`, `Variant = `, `Variant(Type, ..., TypeN)` or `Variant { fields: Types }`"); + err + }) } /// Parses `struct Foo { ... }`. diff --git a/compiler/rustc_parse/src/parser/mod.rs b/compiler/rustc_parse/src/parser/mod.rs index 4d8bff28b05..bebb012660a 100644 --- a/compiler/rustc_parse/src/parser/mod.rs +++ b/compiler/rustc_parse/src/parser/mod.rs @@ -943,6 +943,10 @@ impl<'a> Parser<'a> { Err(e) => { // Parsing failed, therefore it must be something more serious // than just a missing separator. + for xx in &e.children { + // propagate the help message from sub error 'e' to main error 'expect_err; + expect_err.children.push(xx.clone()); + } expect_err.emit(); e.cancel(); -- cgit 1.4.1-3-g733a5