Most SwiftShims were put in the swift namespace in C++ mode which broke certain things when importing them in a swift file in C++ mode. This was OK when they were only imported as part of the swift runtime but, now they are used in C++ mode both in the swift runtime and when C++ interop is enabled.
This broke when C++ interop was enabled because the `Swift` module contains references to symbols in the SwiftShims headers which are built without C++ interop enabled (no "swift" namespace). But, when C++ interop is enabled, the SwiftShims headers would put everything in the swift namespace meaning the symbols couldn't be found in the global namespace. Then, the compiler would error when trying to deserialize the Swift module.
This tells the compiler that repeated calls to this function will always generate the same result, which allows the optimizer to coalesce multiple calls, hoist calls out of loops, and other such nice things.
rdar://problem/20690429
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.
The standard library has grown significantly, and we need a new
directory structure that clearly reflects the role of the APIs, and
allows future growth.
See stdlib/{public,internal,private}/README.txt for more information.
Swift SVN r25876