dotnet/roslyn

VB parsing string-interpolation in erroneous code has poor error recovery

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#3,617 建立於 2015年6月22日

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 (15 留言) (0 反應) (1 負責人)C# (20,414 star) (4,257 fork)batch import
Area-CompilersBugConcept-Diagnostic Clarityhelp wanted

描述

Watch this video: string-interpolation-parsing

I get into this situation often when I'm copying+pasting code around, or breaking a method up into smaller methods by deleting "sub" and then re-adding a bunch of "sub" and "end sub" statements where appropriate.

WHAT I OBSERVE: When there's a valid statement, regular strings and interpolated string parse fine.

When there's an invalid statement, regular strings parse fine, but interpolated strings don't recognize their terminating quote, so the remainder of the entire file gets "stringed out".

WHAT I EXPECT: interpolated strings should believe themselves terminated at the terminating quote, just like regular strings do.

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csharp
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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
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清晰度議題是否清楚說明預期改動、驗收標準和下一步。
clear
前置要求
Visual Basic syntaxcompiler parsing basicserror recovery conceptsRoslyn VB parser code
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
Investigate the VB parser's handling of string interpolation in error recovery. Look at the relevant parsing code in the VB syntax parser, likely in files such as 'VbParse.vb' or 'SyntaxParser.vb'. The issue is that interpolated strings do not terminate on the closing quote when there is a prior syntax error. Examine the existing error recovery logic for regular strings versus interpolated strings and propose a fix that ensures the terminating quote is recognized even in error scenarios.