Introduce a new expression macro that produces an value of type
`(any AnyActor)?` that describes the current actor isolation. This
isolation will be `nil` in non-isolated code, and refer to either the
actor instance of shared global actor in other cases.
This is currently behind the experimental feature flag
OptionalIsolatedParameters.
ASL is deprecated in macOS 10.12. It may be time to transition to os_log now
that deployment targets have been raised to 10.12, but until that project
starts these warnings are just pollution.
Filed rdar://121066531 to track adoption of `os_log()` if appropriate.
Makes the BSD and `__APPLE__` branches consistent and suppresses the following
warning:
```
warning: pointer is missing a nullability type specifier
```
There is a small bug fix here in the identification of the catch node,
where the leading `{` of a closure was considered to be "inside" the
closure for code like
{ ... }()
causing us to assume that the call to the closure would catch the error
within the closure.
Other than that, introduce the thrown error type into the type checker's
modeling of `withoutActuallyEscaping(_:do:)`, and mirror that in the
library declaration.
Make `init(catching:)` and `get()` use typed throws. The former infers
the `Failure` type from the closure provided (once full type inference
is in place) and the latter only throws errors of the `Failure` type.
These are provided for FixedWidthInteger & UnsignedInteger (the base implementation, following Knuth's Algorithm D) and SignedInteger (converting to magnitudes and calling the former). Previously no default implementations were available, requiring every type to implement these operations.
These defaults will not be optimal for large fixed-width integers, so types vending Int512 or similar integers should still provide their own implementations, but they are unconditionally available as a fallback, which simplifies the process of writing such types, and work well enough as a fallback for modest fixed-width integer types like Int64 or 32b or smaller platforms or Int128 on 64b platforms.
Additionally rework the concrete implementations to guarantee that we always trap when the quotient is not representable, and to improve performance for 64b integers on arm64_32, and added some new test coverage for these operations.
These class methods are internal, but because they are overridden and are
part of a `@usableFromInline`, `@_fixed_layout` class, we they can't be
moved over to typed throws without breaking ABI. However, they are
only ever called from typed-throws functions, which already need a
do...catch dance to downcast the error itself. Make them `throws`
instead, which is ABI-compatible, but eliminates the need for
do...catch hackery in the function itself.
Replace the hackish use of `@_disfavoredOverload` with the more principled
use of `@_silgen_name` for the entrypoint we are maintaining, then rename
these functions in source to `__rethrows_map` to indicate what they're for.
While here, make them `throws` instead of `rethrows`. The ABI is the
same, and `throws` allows us do avoid to do/catch tricks with rethrows
functions.
Adopt typed throws for the `map` operation to propagate thrown error
types through the `map` API. This is done in a manner that is backward
compatible for almost all cases:
* The new typed-throws entrypoint is `@_alwaysEmitIntoClient` so it
can back-deploy all the way back.
* The old `rethrows` entrypoint is left in place, using
`@usableFromInline` with `internal` so it is part of the ABI but not
the public interface, and `@_disfavoredOverload` so the type checker
avoids it while building the standard library itself. The old
entrypoint is implemented in terms of the new one.
Note that the implementation details for the existential collection
"box" classes rely on method overriding of `_map` operations, and the
types are frozen, so we don't get to change their signatures. However,
these are only implementations, not API: the actual API `map`
functions can be upgraded to typed throws.
Note that this code makes use of a known hole in `rethrows` checking
to allow calling between `rethrows` and typed throws. We'll need to do
something about this for source-compatibility reasons, but I'll follow
up with that separately.
Obsolete the `-enable-swift3-objc-inference` option and related options by
removing support for inferring `@objc` attributes using Swift 3 rules.
Automated migration from Swift 3 has not been supported by the compiler for
many years.
Create a version of the metadata specialization code which is abstracted so that it can work in different contexts, such as building specialized metadata from dylibs on disk rather than from inside a running process.
The GenericMetadataBuilder class is templatized on a ReaderWriter. The ReaderWriter abstracts out everything that's different between in-process and external construction of this data. Instead of reading and writing pointers directly, the builder calls the ReaderWriter to resolve and write pointers. The ReaderWriter also handles symbol lookups and looking up other Swift types by name.
This is accompanied by a simple implementation of the ReaderWriter which works in-process. The abstracted calls to resolve and write pointers are implemented using standard pointer dereferencing.
A new SWIFT_DEBUG_VALIDATE_EXTERNAL_GENERIC_METADATA_BUILDER environment variable uses the in-process ReaderWriter to validate the builder by running it in parallel with the existing metadata builder code in the runtime. When enabled, the GenericMetadataBuilder is used to build a second copy of metadata built by the runtime, and the two are compared to ensure that they match. When this environment variable is not set, the new builder code is inactive.
The builder is incomplete, and this initial version only works on structs. Any unsupported type produces an error, and skips the validation.
rdar://116592420
