dotnet/roslyn

Parse await expression in VB when method is not async

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#10,320 建立於 2016年4月4日

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 (2 留言) (0 反應) (0 負責人)C# (20,414 star) (4,257 fork)batch import
Area-CompilersBugConcept-Diagnostic ClarityLanguage-VBhelp wanted

描述

If you use an await expression in VB when the enclosing method is not async, you get an error that you cannot use await in a non-async method, and you also get a syntax error. In most cases we could drop the syntax error and just report the former error message.

We could also check that we bind properly if we relax the parser. See C# issue #10232.

貢獻者指南

技術棧
csharp
領域
tooling
議題類型
bug
難度面向新貢獻者的預計實作難度，1 表示很小改動，5 表示專家級工作。
3
預計時間有經驗貢獻者完成調查、實作、測試並準備 pull request 的粗略時間範圍。
1-3 hours
活動狀態議題目前的可參與程度：新鮮、活躍、陳舊、阻塞或等待維護者輸入。
stale
清晰度議題是否清楚說明預期改動、驗收標準和下一步。
mostly clear
前置要求
basic understanding of Roslyn parserVB.NET languageerror handling in compilers
新手友善度1-100 的估計分數，表示該議題對首次貢獻者的友善程度。
30
研究方向
Examine the VB parser code in the Roslyn repository, particularly the part that parses await expressions. Review the linked C# issue #10232 for a similar fix pattern. Identify where the syntax error is emitted and ensure that only the semantic error (await in non async method) is reported, dropping the redundant syntax error.