swiftlang/swift

Bad diagnostic for `any P!`

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#72,662 建立於 2024年3月28日

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 (6 留言) (0 反應) (2 負責人)Swift (69,989 star) (10,719 fork)batch import
TypeResolverbugcompilerdiagnostics qualityexistentialsgood first issueimplicitly unwrapped optionalsswift 6.0type checkertypesunexpected behavior

描述

Description

No response

Reproduction

protocol P {}

// error: using '!' is not allowed here; perhaps '?' was intended? [implicitly_unwrapped_optional_in_illegal_position]
// error: optional 'any' type must be written '(any P2)?' [incorrect_optional_any]
let _: any P!

Expected behavior

A single error, optional 'any' type must be written '(any P)!', as in the case of let _: any P?.

Environment

Swift version 6.0-dev (LLVM 48dc0c6fa01ce9e, Swift 19fbe5b33d423d1) Target: x86_64-apple-macosx14.0

Additional information

This https://github.com/apple/swift/labels/good%20first%20issue will suit an experienced Swift user.

貢獻者指南

技術棧
swift
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。
half day
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。
blocked
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
Swift compiler basicsDiagnostic system
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。
40
研究方向
This bug report describes an incorrect diagnostic for `any P!` in Swift. The compiler currently emits two errors instead of one when encountering an implicitly unwrapped optional in an illegal position with `any`. The fix likely involves modifying the error checking logic in the parser or type checker to suppress the spurious first error. The issue has two assignees but no open PRs, indicating someone may be working on it. Comments on the issue may provide additional context.