Mention the type, the requirement, and the extension in the error that
follows. In editor mode, try to insert stubs for the missing requirement
as well so the user isn't just left with a pile of unactionable errors.
The change to resolve ObjC #keyPath expression components caused some source
breakage as they are now being checked for availability issues. This change
updates availability checking to demote error diagnostics to warnings
within #keyPath expressions. There were cases in the source compat suite where
unavailble properites were used in #keyPath expressions, but they caused no
issues at runtime because the properties' ObjC runtime name was still correct
(e.g. the same as its renamed-to property in Swift).
* [Parser] Update 'Confusables.def' file to include confusable and base character names
* [Parser] Add a new utility method to return the names of the confusable and base characters for a given confusable codepoint
* [Parser] Update diagnostic for confusable character during lexing to mention confusable and base character names
* [Sema] If there is just a single confusable character, emit a tailored diagnostic that also mentions the character names
* [Diagnostics] Add new diagnostic messages to the localization file
* [Test] Update confusables test
* [Utils] Update unicode confusables txt file and update script to regenerate confusables def file
* [Parse] Regenerate 'Confusables.def' using updated script
* [Utils] Adjust generate_confusables script based on review feedback
Fix a mistake with name mapping. Updated header comment. Fix a couple of linting issues.
* [Parse] Regenerate 'Confusables.def' file once again after script changes
* [Parse] Add the newline after end of 'getConfusableAndBaseCodepointNames' method
* [Test] Update diagnostic message in 'Syntax/Parser/diags.swift'
* [Diagnostics] Update 'does not override' diagnostic message to include protocol context as well
* [Sema] Check whether the override context is a class or a protocol for diagnostic purposes
* [Test] Update tests with new diagnostic message for overrides in protocol context
* [Sema] Adjust diagnostic for overrides in structs and enums to use the existing 'override_nonclass_decl' diagnostic
This change permits a subclass to redeclare an unavailable member from a superclass. For instance, suppose you write this code (or, more likely, a version where `Base` is an ObjC class):
```swift
class Base {
@available(*, unavailable) init() {}
}
class Derived: Base {
/* override */ init() {}
}
```
Previously, Swift would reject `Derived.init()` without the `override` keyword, telling you that you should add it, but it would also reject it *with* the `override` keyword, telling you that you can't override something that's unavailable. This PR makes Swift accept it without the `override` keyword; declaring it with the keyword is still forbidden.
Fixes rdar://65702529.
