swiftlang/swift

[SR-5984] Error message for accidentally calling function in #selector(foo()) could suggest removing parens

Open

#48,543 创建于 2017年9月26日

在 GitHub 查看
 (3 评论) (0 反应) (0 负责人)Swift (69,989 star) (10,719 fork)batch import
bugcompilerdiagnostics qualitygood first issuetype checker

描述
Previous ID SR-5984
Radar rdar://problem/34640740
Original Reporter @huonw
Type Bug
Status In Progress
Resolution

Swift 4.0
Votes 0
Component/s Compiler
Labels Bug, DiagnosticsQoI, StarterBug, TypeChecker
Assignee None
Priority Medium

md5: 939952c8851f309540d6ce3aaa7d7c15

Issue Description:

import Foundation

class Foo {
    @objc func foo() {
        _ = #selector(foo())
    }
}

call-selector.swift:5:13: error: argument of '#selector' does not refer to an '@objc' method, property, or initializer
        _ = #selector(foo())
            ^         ~~~~~

This is close to the correct syntax (#selector(foo)) and the compiler could help guide the user to this. This probably comes up most often with selectors for methods with no arguments (https://bugs.swift.org/browse/SR-1016).

贡献者指南

技术栈
swiftcpp
领域
developer experiencetooling
议题类型
bug
难度面向新贡献者的预计实现难度，1 表示很小改动，5 表示专家级工作。
3
预计时间有经验贡献者完成调查、实现、测试并准备 pull request 的粗略时间范围。
half day
活动状态议题当前的可参与程度：新鲜、活跃、陈旧、阻塞或等待维护者输入。
stale
清晰度议题是否清楚说明期望改动、验收标准和下一步。
clear
前置要求
Swift programming languagecompiler diagnosticsC++ basicsXcode or build environment
新手友好度1-100 的估计分数，表示该议题对首次贡献者的友好程度。
60
研究方向
This issue suggests improving the error message for `#selector(foo())` to suggest removing parentheses, similar to SR 1016. The modification is likely in the Swift compiler's type checker or diagnostic emission code, specifically in files related to selector handling. Start by examining the existing error message in the compiler source, possibly in `lib/Sema/TypeCheckObjC.cpp` or similar. Look for how `#selector` is validated and where the error 'argument of #selector does not refer to an @objc method' is generated. The goal is to detect when the user accidentally included parentheses and emit a fix it hint.
[SR-5984] Error message for accidentally calling function in #selector(foo()) could suggest removing parens · swiftlang/swift#48543 | Good First Issue