This revises and expands upon documentation for the standard library's
unsafe pointer types. This includes typed and raw pointers and buffers,
the MemoryLayout type, and some other top-level functions.
We need the encode string to be able to construct NSValues using the core valueWithBytes:objCType: API. This builtin only works with concrete, @objc-representable types for now, which should be sufficient for a stdlib-internal API.
We want to be robust against unexpected `nil`s when bringing `id`s into Swift as `Any`. Add a function that builds an AnyObject?-in-an-Any when we unexpectedly receive a nil.
As of now:
* old APIs are just marked as `deprecated` not `unavaiable`. To make it
easier to co-operate with other toolchain repos.
* Value variant of API is implemented as public @private
`_ofInstance(_:)`.
Update for SE-0107: UnsafeRawPointer
This adds a "mutating" initialize to UnsafePointer to make
Immutable -> Mutable conversions explicit.
These are quick fixes to stdlib, overlays, and test cases that are necessary
in order to remove arbitrary UnsafePointer conversions.
Many cases can be expressed better up by reworking the surrounding
code, but we first need a working starting point.
* Migrate from `UnsafePointer<Void>` to `UnsafeRawPointer`.
As proposed in SE-0107: UnsafeRawPointer.
`void*` imports as `UnsafeMutableRawPointer`.
`const void*` imports as `UnsafeRawPointer`.
Occurrences of `UnsafePointer<Void>` are replaced with UnsafeRawPointer.
* Migrate overlays from UnsafePointer<Void> to UnsafeRawPointer.
This requires explicit memory binding in several places,
particularly in NSData and CoreAudio.
* Fix a bunch of test cases for Void->Raw migration.
* qsort takes IUO values
* Bridge `Unsafe[Mutable]RawPointer as `void [const] *`.
* Parse #dsohandle as UnsafeMutableRawPointer
* Update a bunch of test cases for Void->Raw migration.
* Trivial fix for the SceneKit test case.
* Add an UnsafeRawPointer self initializer.
This is unfortunately necessary for assignment between types imported from C.
* Tiny simplification of the initializer.
* Migrate from `UnsafePointer<Void>` to `UnsafeRawPointer`.
As proposed in SE-0107: UnsafeRawPointer.
`void*` imports as `UnsafeMutableRawPointer`.
`const void*` imports as `UnsafeRawPointer`.
Occurrences of `UnsafePointer<Void>` are replaced with UnsafeRawPointer.
* Migrate overlays from UnsafePointer<Void> to UnsafeRawPointer.
This requires explicit memory binding in several places,
particularly in NSData and CoreAudio.
* Fix a bunch of test cases for Void->Raw migration.
* qsort takes IUO values
* Bridge `Unsafe[Mutable]RawPointer as `void [const] *`.
* Parse #dsohandle as UnsafeMutableRawPointer
* Update a bunch of test cases for Void->Raw migration.
* Trivial fix for the SceneKit test case.
* Add an UnsafeRawPointer self initializer.
This is unfortunately necessary for assignment between types imported from C.
* Tiny simplification of the initializer.
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.
- Previously we didn't know how to bridge address-only types. Add some
plumbing for this. Not fully general yet, but with a bit more work we
could allow resilient value types to adopt _ObjectiveCBridgable, too.
For now, this is just intended to support the id-as-Any work.
- Specifically when going from a type without any other known bridging
strategy, emit a call to the new `_bridgeAnythingToObjectiveC` entry
point from the previous commit.
The general rule here is that something needs to be SWIFT_CC(swift)
if it's just declared in Swift code using _silgen_name, as opposed to
importing something via a header.
Of course, SWIFT_CC(swift) expands to nothing by default for now, and
I haven't made an effort yet to add the indirect-result / context
parameter ABI attributes. This is just a best-effort first pass.
I also took the opportunity to shift a few files to just implement
their shims header and to demote a few things to be private stdlib
interfaces.
Implements SE-0055: https://github.com/apple/swift-evolution/blob/master/proposals/0055-optional-unsafe-pointers.md
- Add NULL as an extra inhabitant of Builtin.RawPointer (currently
hardcoded to 0 rather than being target-dependent).
- Import non-object pointers as Optional/IUO when nullable/null_unspecified
(like everything else).
- Change the type checker's *-to-pointer conversions to handle a layer of
optional.
- Use 'AutoreleasingUnsafeMutablePointer<NSError?>?' as the type of error
parameters exported to Objective-C.
- Drop NilLiteralConvertible conformance for all pointer types.
- Update the standard library and then all the tests.
I've decided to leave this commit only updating existing tests; any new
tests will come in the following commits. (That may mean some additional
implementation work to follow.)
The other major piece that's missing here is migration. I'm hoping we get
a lot of that with Swift 1.1's work for optional object references, but
I still need to investigate.
This is a staging attribute that will eventually mean "fixed-contents"
for structs and "closed" for enums, as described in
docs/LibraryEvolution.rst.
This is pretty much the minimal set of types that must be fixed-layout,
because SILGen makes assumptions about their lowering.
If desired, some SILGen refactoring can allow some of these to be
resilient. For example, bridging value types could be made to work
with resilient types.
This lets us eliminate the _getObjectiveCType() value witness, which
was working around the lack of proper type witness metadata in witness
tables. Boilerplate -= 1.
This reverts commit 052d2d0a69.
The only actual issue with the original change was a missing change to
the UIApplicationMain SILGen test, which needs to build SILGen
overlays to execute properly; -enable-source-import doesn't suffice.
Introduce a new entrypoint to _ObjectiveCBridgeable,
_unconditionallyBridgeFromObjectiveC, which handles unconditional
bridging from an optional Objective-C object (e.g., an NSString) to
its bridged Swift type. Use it in SILGen to perform NSString -> String
bridging rather than the custom entry point.
Another small step toward generalized bridging.
