For a value of an opaque generic type `<T> x: T`, the language currently defines `type(of: x)` and `T.self` as both producing a type `T.Type`, and the result of substituting an existential type by `T == P` gives `P.Protocol`, so the `type(of:)` operation on `x` can only give the concrete protocol metatype when `x` is an existential in this case. The optimizer understood this rule, but the runtime did not, causing SR-3304.
Changes:
* Terminate all namespaces with the correct closing comment.
* Make sure argument names in comments match the corresponding parameter name.
* Remove redundant get() calls on smart pointers.
* Prefer using "override" or "final" instead of "virtual". Remove "virtual" where appropriate.
classType is unused without ObjC interop. Simplify the code a bit by increasing
the scope covered by the SWIFT_OBJC_INTEROP. It also silences the warning.
Previously we had two separate mechanisms to turn a metatype
into a string. The swift_typeName() function was used to print
the metatype in a human-readable fashion, whereas the
_swift_buildDemanglingForMetadata() was used when naming
generated generic Objective-C classes.
Unify them, since what swift_typeName() does is redundant;
instead of going directly from the metatype to a human-readable
string, we can get the mangling, and print that using the
demangler.
This fixes some issues with unnecessary parenthesis when
printing function types, and also allows Objective-C classes
to be instantiated with nested generic types as parameters.
We neglected to pass down the Hashable witness table parameters, leading to Heisenbugs because we would call into invalid witness pointers occasionally when loading the Hashable conformance from corrupted metadata. Fixes rdar://problem/28022201.
This allows dynamic casting to succeed between tuple types with
different element types, converting each element in turn. Fixes
rdar://problem/19892202.
Introduce narrow support for tuple/tuple dynamic casts that merely add
or remove labels, but require the element types to match exactly. This
gets us back to allowing the same correct dynamic casts as in Swift
3.0, when labels were completely ignored.
id-as-Any lets you pass Optional to an ObjC API that takes `nonnull id`, and also lets you bridge containers of `Optional` to `NSArray` etc. When this occurs, we can unwrap the value and bridge it so that inhabited optionals still pass into ObjC in the expected way, but we need something to represent `none` other than the `nil` pointer. Cocoa provides `NSNull` as the canonical "null for containers" object, which is the least bad of many possible answers. If we happen to have the rare nested optional `T??`, there is no precedented analog for these in Cocoa, so just generate a unique sentinel object to preserve the `nil`-ness depth so we at least don't lose information round-tripping across the ObjC-Swift bridge.
Making Optional conform to _ObjectiveCBridgeable is more or less enough to make this all work, though there are a few additional edge case things that need to be fixed up. We don't want to accept `AnyObject??` as an @objc-compatible type, so special-case Optional in `getForeignRepresentable`.
Implements SR-0140 (rdar://problem/27905315).
id-as-Any lets you pass Optional to an ObjC API that takes `nonnull id`, and also lets you bridge containers of `Optional` to `NSArray` etc. When this occurs, we can unwrap the value and bridge it so that inhabited optionals still pass into ObjC in the expected way, but we need something to represent `none` other than the `nil` pointer. Cocoa provides `NSNull` as the canonical "null for containers" object, which is the least bad of many possible answers. If we happen to have the rare nested optional `T??`, there is no precedented analog for these in Cocoa, so just generate a unique sentinel object to preserve the `nil`-ness depth so we at least don't lose information round-tripping across the ObjC-Swift bridge.
Making Optional conform to _ObjectiveCBridgeable is more or less enough to make this all work, though there are a few additional edge case things that need to be fixed up. We don't want to accept `AnyObject??` as an @objc-compatible type, so special-case Optional in `getForeignRepresentable`.
Implements SR-0140 (rdar://problem/27905315).
This makes it a bit easier to diagnose unexpected boxing problems in the debugger, by allowing `po [value _swiftTypeName]` to work, instead of forcing users to know how to call `swift_getTypeName` from lldb themselves.
If the Swift error wrapped in a _SwiftNativeNSError box conforms to
Hashable, the box now uses the Swift's conformance to Hashable.
Part of rdar://problem/27574348.
SILGen already attempts to extract an embedded NSError when
type-erasing to an Error existential; make the runtime do the same
thing dynamically.
Huge thanks to Joe Groff who noticed that I missed this path.
Imported Cocoa error types are represented by structs wrapping an
NSError. The conversion from these structs to Error would end up
boxing the structs in _SwiftNativeNSError, losing identity and leading
to a wrapping loop.
Instead, extract the embedded NSError if there is one. In the Swift
runtime, do this as part of the dynamic cast to NSError, using a (new,
defaulted) requirement in the Error type so we can avoid an extra
runtime lookup of the protocol. In SILGEn, do this by looking for the
_BridgedStoredNSError protocol conformance when erasing to an Error
type. Fixes SR-1562 / rdar://problem/26370984.
All generic bridgeable types can bridge for all their instantiations now. Removing this ferrets out some now-unnecessary traps that check for unbridgeable parameter types.
- Any is made into a keyword which is always resolved into a TypeExpr,
allowing the removal of the type system code to find TheAnyType before
an unconstrained lookup.
- Types called `Any` can be declared, they are looked up as any other
identifier is
- Renaming/redefining behaviour of source loc methods on
ProtocolCompositionTypeRepr. Added a createEmptyComposition static
method too.
- Code highlighting treats Any as a type
- simplifyTypeExpr also does not rely on source to get operator name.
- Any is now handled properly in canParseType() which was causing
generic param lists containing ‘Any’ to fail
- The import objc id as Any work has been relying on getting a decl for
the Any type. I fix up the clang importer to use Context.TheAnyType
(instead of getAnyDecl()->getDeclaredType()). When importing the id
typedef, we create a typealias to Any and declare it unavaliable.
