Now that the cached character stride in indices always mean the
stride in the full string, we can stop looking at whether a substring
has a character-aligned end index.
This fixes a compatibility issue with potential future UTF-8 encoded
foreign String forms, as well as simplifying the code a bit — we no
longer need to do an availability check on inlinable fast paths.
The isForeignUTF8 bit is never set by any past or current stdlib
version, but it allows us to introduce UTF-8 encoded foreign forms
without breaking inlinable index encoding validation introduced in
Swift 5.7.
- Split forward and backward direction into separate code paths.
This makes the code more readable and paves the way for future
improvements. (E.g., switching to a linear-time algorithm for
breaking backwards.)
- `Substring.index(after:)` now uses the same grapheme breaking paths
as `String.index(after:)`.
- The cached stride value in string indices is now well-defined even
on indices that aren’t character-aligned.
Emit and resolve idValue of KeyPath as an absolute pointer if relative
function pointer is turned-off on Wasm target.
The existing ABI can't distinguish an idValue between function pointer
or data pointer in use-site at compile-time and also at runtime. So this
patch adds a new id resolution scheme `ResolvedAbsolute` to distinguish
them at runtime properly.
When SWIFT_COMPACT_ABSOLUTE_FUNCTION_POINTER is enabled, relative direct
pointers whose pointees are functions will be turned into absolute
pointer at compile-time.
Starting with Android 11, AArch64 placed a tag in the top byte of pointers to
allocations, which has been slowly rolling out to more devices and collides
with Swift's tags. Moving these tags to the second byte works around this
problem.
Moved the _gCRAnnotations declarations to their own object module,
which will help to avoid duplicate symbol problems (at least with .a
files).
Also tweaked things to make it so that the demangler and runtime
versions of the message setting code will interoperate (and so that
they'll interoperate better with other implementations that might
creep in from somewhere, like the one in LLVMSupport).
rdar://91095592
