Add a missing fix_lifetime. This miscompiles with OSSA because
`object` is destroyed before `bridgeObject` is retained.
Reinterpreting a reference to a trivial type always requires a
fix_lifetime.
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.
Old Swift and new Swift runtimes and overlays need to coexist in the same process. This means there must not be any classes which have the same ObjC runtime name in old and new, because the ObjC runtime doesn't like name collisions.
When possible without breaking source compatibility, classes were renamed in Swift, which results in a different ObjC name.
Public classes were renamed only on the ObjC side using the @_objcRuntimeName attribute.
This is similar to the work done in pull request #19295. That only renamed @objc classes. This renames all of the others, since even pure Swift classes still get an ObjC name.
rdar://problem/46646438
This commit supersedes 2866b4a which was overwritten by 4ab45df.
Store small string code units in little-endian byte order. This way
the code units are in the same order on all machines and can be
safely treated as an array of bytes.
In anticipation of potential future HW features, e.g. armv8.5 memory
tagging, only use the high 4 bytes as discriminator bits in
_BridgeObject rather than the top 8 bits. Utilize two perf flags to
cover this instead. This requires shifting around a fair amount of
internal complexity.
Remove Discriminator, Flags, etc., abstractions from
StringObject. These cause code divergence between 32-bit and 64-bit
ABI, complicate ABI changes, and otherwise contribute to bloat.
We now have plenty of extra inhabitants in the variant enum, so we can get rid of the 7-bit hack.
It’d also be possible now to increase small string capacity to a spacious 11 bytes; however this needs a full overhaul of the 32-bit representation, so it needs a little bit more time in the oven.
Less inlining for hashing and comparison. Saves code size on very
frequent String comparison in exchange for costing us in some of our
ridiculuous micro-benchmarks.
Also adds in more _effects for better codegen
After rebasing on master and incorporating more 32-bit support,
perform a bunch of cleanup, documentation updates, comments, move code
back to String declaration, etc.
Refactor and rename _StringGutsSlice, apply NFC-aware fast paths to a
new buffered iterator.
Also, fix bug in _typeName which used to assume ASCIIness and better
SIL optimizations on StringObject.
Add inlinability annotations to restore performance parity with 4.2 String.
Take advantage of known NFC as a fast-path for comparison, and
overhaul comparison dispatch.
RRC improvements and optmizations.
* Refactor out RRC implementation into dedicated file.
* Change our `_invariantCheck` pattern to generate efficient code in
asserts builds and make the optimizer job's easier.
* Drop a few Bidi shims we no longer need.
* Restore View decls to String, workaround no longer needed
* Cleaner unicode helper facilities
This is a giant squashing of a lot of individual changes prototyping a
switch of String in Swift 5 to be natively encoded as UTF-8. It
includes what's necessary for a functional prototype, dropping some
history, but still leaves plenty of history available for future
commits.
My apologies to anyone trying to do code archeology between this
commit and the one prior. This was the lesser of evils.
* Remove case destructuring to _
* Remove some Iterator.Element
* Which idiot wrote this? Oh.
* Switch NibbleSort to just use default impls... shouldn't change perf
The resilience model forces inlinable code to use resiliently conservative access paths for properties in the same module, but some stdlib methods by design escapes storage of a global variable. The additional `Builtin.addressof` validation introduced in #15608 exposed the latent issue here.
Switch StringObject and StringGuts from opaquely storing tagged cocoa
strings into storing small strings. Plumb small string support
throughout the standard library's routines.
In theory there could be a "fixed-layout" enum that's not exhaustive
but promises not to add any more cases with payloads, but we don't
need that distinction today.
(Note that @objc enums are still "fixed-layout" in the actual sense of
"having a compile-time known layout". There's just no special way to
spell that.)
[string] Clean up StringObject; Clarify its tagged BridgeObjects.
Bifurcate StringObjects raw bit-pattern initializers to expose whether
the caller is passing a value rather than a reference. This way,
StringObject can call the approprite BridgeObject helper and
participate in upcoming peephole optimizations like retains of
known-values. This is all meant to be a NOP.
Additionally, do some cleanup while we're at it.
Include the initial implementation of _StringGuts, a 2-word
replacement for _LegacyStringCore. 64-bit Darwin supported, 32-bit and
Linux support in subsequent commits.
