These are tests that fail in the next commit without this flag. This
does not add -verify-ignore-unrelated to all tests with -verify, only
the ones that would fail without it. This is NFC since this flag is
currently a no-op.
This is reasonable to diagnose with a warning, but dropping the 'open'
down to 'public' isn't the right fix, because now it's not a valid
override. The declaration has to get moved to another extension instead,
or the extension has to not set a default access level.
This turned out to be a source compat issue because the same logic
that emits the fix-it also updates the access of the member, which
then resulted in "must be as accessible as the declaration it
overrides" in the /same/ build. It's not immediately clear what caused
this; probably something's just being validated in a different order
than it was before. The change makes sense either way.
Stepping back, it's weird that a warning would change how the compiler
saw the code, and while we could check for 'override' explicitly, we
can't know if the member might be satisfying a protocol requirement.
Better to just not guess at the right answer here.
rdar://problem/47557376&28493971
NSObject.hashValue is provided to satisfy the hashValue constraint of
the Hashable protocol. However, it is not the correct customization
point for interoperating with Objective-C, because Objective-C code
will call through the -hash method. Warn about overrides of
NSObject.hashValue; users should override NSObject.hash instead.
Fixes rdar://problem/42780635.
Rather than deferring to the heavyweight validateDeclForNameLookup()
to perform the “get overridden decls” operation, perform a much more
minimal validation that only looks for exact matches when the ‘override’
modifier is present.
The more-extensive checking (e.g., that one didn’t forget an override
modifier) is only performed as part of the “full” type checking of
a declaration, which will typically only be done within the same source
file as the declaration. The intent here is to reduce the amount of
work performed to check overrides cross-file, and limit the dependencies
of the “get overridden decls” operation.
In today's Swift, only non-optional function parameters can be
non-escaping (and are by default). An optional function parameter uses
a function type as a generic argument to Optional, and like any other
generics that's considered an opaque and therefore possibly escaping
use of the type. This is certainly unfortunate since it means a
function parameter cannot be both Optional and non-escaping.
However, this "unfortunate" becomes a concrete problem when dealing
with Objective-C, which /does/ allow applying its 'noescape' attribute
to a callback block marked 'nullable'. This is fine for /uses/ of
methods with such parameters, but prevents anyone from /overriding/
these methods.
This patch pokes a very narrow hole into the override checking to
accomodate this: if a declaration comes from Objective-C, and it has
an optional, non-escaping closure parameter, it's okay to override it
in Swift with an optional, escaping closure parameter. This isn't
strictly safe because a caller could be relying on the
non-escaping-ness, but we don't have anything better for now. (This
behavior will probably be deprecated in the future.)
(Some people have noted that the old 'noescape' type attribute in
Swift still works, albeit with a warning. That's not something people
should have to type, though---we want to remove it from the language,
as described in SE-0103.)
rdar://problem/32903155
