Without this change, SILGen will crash when compiling a use of the
derived protocol's requirement: it will instead attempt to use
the base protocol's requirement, but the code will have been
type-checked incorrectly for that.
This has a potential for source-compatibility impact if anyone's
using explicit override checking for their protocol requirements:
reasonable idioms like overriding a mutating requirement with a
non-mutating one will no longer count as an override. However,
this is arguably a bug-fix, because the current designed intent
of protocol override checking is to not allow any differences in
type, even "covariant" changes like making a mutating requirement
non-mutating. Moreover, we believe explicit override checking in
protocols is quite uncommon, so the overall compatibility impact
will be low.
This also has a potential for ABI impact whenever something that
was once an override becomes a non-override and thus requires a
new entry. It might require a contrived test case to demonstrate
that while using the derived entry, but it's quite possible to
imagine a situation where the derived entry is not used directly
but nonetheless has ABI impact.
Furthermore, as part of developing this patch (earlier versions of
which used stricter rules in places), I discovered a number of
places where the standard library was unintentionally introducing
a new requirement in a derived protocol when it intended only to
guide associated type deduction. Fixing that (as I have in this
patch) *definitely* has ABI impact.
* Make SIMD types codable. We're considering this a bugfix.
This is a very tiny ABI change, in that user-defined SIMD types compiled with an earlier version of 5.0 will be missing the necessary conformance to Codable. Discussed with Ben, and we're OK with this because we don't think there are such types yet, and it can be fixed with a recompile.
* Add basic tests
Many Foundation initializers could benefit from faster string
construction and subsequent reads in Swift 5. Add UTF-8 fast paths for
when constructing a string from a valid UTF-8 code units.
JSONEcoder/Decoder get another underscore in their ObjC name, as the one with a single underscore conflicts with older Swifts that had _JSONEcoder/Decoder as internal rather than fileprivate.
_JSONEncoder/Decoder get another underscore in their Swift name to avoid conflicting with the ObjC name from the ones in older overlays.
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 refactoring uses large portions of the already existing code for
x86_64 and s390 to implement AAPCS64 __VaListBuilder. The parts where
each implementation differ are the x86_64 header, and the order of the
general and vector registers.
The changes also addresses many of the request from the reviewers in
#20862 which were not addressed originally, like the reuse of the
already existing code, and the generalizations for the code to be useful
for platforms different than Linux (Android, for example).
Colocate the target specific library specification. Inline the single
site use of the place holder ICU_UC and ICU_I18N libraries rather than
trying to create special library processing code for that.
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.
* Revise the Unicode scalar/Character properties
* Minor revisions to `compactMapValues` docs.
* Add documentation for AdditiveArithmetic, revise Numeric
* Apply minor style updates to count(where:).
* Revise string interpolation docs.
- Convert table of interpolation examples to a list of examples. Tables
aren't supported by Swift markup, so this wouldn't render properly in
Xcode or on the web.
- Add a description of what a user must implement in a custom
string interpolation type to get the behavior they want.
* Revise isMultiple(of:) docs.
- In particular, add emphasis to mathematical symbols and equations to
match how we document such things elsewhere.
- I'm using asterisks for single symbols, and underscores for equations
because it's easier to read in-source when you don't have to escape
multiplication within emphasis.
* Add some abstracts to the SIMD vector types.
- Adds a dictionary of spelled out numbers. Only numbers < 10
should be spelled out according to editorial.
- Adds abstracts to some of the basic members.
- Includes parameter descriptions for the xyzw properties and inits,
but not for the unlabeled initializers. Combined with the protocol
extension method abstracts, this should complete coverage of the concrete
types.
