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.
One additional tweak (setting the scalar-aligned bit on foreign indices) had to be made to avoid a performance regression for long non-ASCII foreign strings.
• Convert _AbstractStringStorage to a protocol, and the free functions used to deduplicate implementations to extensions on that protocol.
• Move 'start' into the abstract type and use that to simplify some code
• Move the ASCII fast path for length into UTF16View.
• Add a weirder but faster way to check which (if any) of our NSString subclasses a given object is, and adopt it
Use the portable spelling for the nullability keywords (_Nullable, _Nonnullable,
_Null_unspecified) rather than the old spelling (__nullable, __nonnullable,
__null_unspecified). NFC.
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.
This allows removal of the DebugDescription protocol which is invalid
because no classes actually conform to it. The problem is that we need
to send a debugDescription message to an NSObject without loading
Foundation. This is exactly what shims are for. A very simple shim
solves the problem.
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
