[SR-7230] Improve error message for statement that begins with open brace · swiftlang/swift#49778

(0 留言) (0 反應) (0 負責人)Swift (69,989 star) (10,719 fork)batch import

bugcompilerdiagnostics qualitygood first issue

描述


Previous ID	SR-7230
Radar	None
Original Reporter	@jckarter
Type	Bug


Votes	0
Component/s	Compiler
Labels	Bug, DiagnosticsQoI, StarterBug
Assignee	None
Priority	Medium

md5: 809fd159923a9a4b4bcf2169a9eb2a66

Issue Description:

Swift doesn't allow a statement to begin with an open brace, and the error message you get when you do is hostile to beginners, talking about "unused closures" rather than the syntactic issue:

https://twitter.com/twostraws/status/975740708601593857

This is likely to come up when a user is moving code around, so the error and associated fixits could be greatly improved.

貢獻者指南

技術棧: swift
領域: developer experience
議題類型: bug
難度: 2
預計時間: 1-3 hours
活動狀態: fresh
清晰度: clear
前置要求: basic Swift syntaxunderstanding of compiler diagnostics
新手友善度: 85
研究方向: Investigate the Swift compiler's parser in lib/Parse/Parser.cpp or related files to locate where errors for statements starting with open braces are emitted. The current error message mentions 'unused closures' instead of a syntax error. Improve the diagnostic to clearly indicate that a statement cannot begin with a brace and suggest possible corrections (e.g., wrapping in a closure or using a construct like `do {}`). Also update any fix it hints accordingly.