[SR-7406] Require availability checks for Swift KeyPath

jegnux commented 6 years ago


Previous ID	SR-7406
Radar	rdar://problem/39319212
Original Reporter	@jegnux
Type	Bug
Status	Resolved
Resolution	Done

Attachment: Download

Additional Detail from JIRA

| | | |------------------|-----------------| |Votes | 0 | |Component/s | Compiler | |Labels | Bug, KeyPaths | |Assignee | None | |Priority | Medium | md5: d56d2e77f97faa4da5f5f1f09f41acf5

is duplicated by:

SR-7402 Do availability checking on key path literals

Issue Description:

Description

Using a KeyPath of a new property is possible without any availability check, leading to a crash at runtime.

Steps to reproduce

Create a project with iOS 10.0 as iOS deployment target

In a UIViewController, write this line:

navigationItem[keyPath: \UINavigationItem.largeTitleDisplayMode] = .always

Expected Results

Have a compiler error:

'largeTitleDisplayMode' is only available on iOS 11.0 or newer

Have following Xcode fix-it:

Add 'if #available' version check
Add @available attribute to enclosing instance method
Add @available attribute to enclosing class

Actual Results

No compiler error, warning or wathever
When the code is run on iOS 10, an unrecognized selector sent to instance exception is thrown

belkadan commented 6 years ago

@swift-ci create

slavapestov commented 6 years ago

https://github.com/apple/swift/pull/17778

swiftlang / swift