Concise magic file names
Concise magic file names 관련
Available from Swift 5.8
SE-0274 (apple/swift-evolution) adjusts the #file magic identifier to use the format Module/Filename, e.g. MyApp/ContentView.swift. Previously, #file contained the whole path to the Swift file, e.g. /Users/twostraws/Desktop/WhatsNewInSwift/WhatsNewInSwift/ContentView.swift, which is unnecessarily long and also likely to contain things you’d rather not reveal.
Important
Right now this behavior is not enabled by default. SE-0362 (apple/swift-evolution) adds a new -enable-upcoming-feature compiler flag designed to let developers opt into new features before they are fully enabled in the language, so to enable the new #file behavior you should add -enable-upcoming-feature ConciseMagicFile to Other Swift Flags in Xcode.
If you’d like to have the old behavior after this flag is enabled, you should use #filePath instead:
// New behavior, when enabled
print(#file)
// Old behavior, when needed
print(#filePath)
The Swift Evolution proposal for this change (apple/swift-evolution) is worth reading because it mentions surprisingly large improvements in binary size and execution performance, and also for this quite brilliant paragraph explaining why having the full path is often a bad idea:
“The full path to a source file may contain a developer's username, hints about the configuration of a build farm, proprietary versions or identifiers, or the Sailor Scout you named an external disk after.”
Other Changes in Swift 5.8