Modeling the universal AvailabilityDomain as the bottom element of a lattice
containing all domains was useful for checking unavailability, but it makes
some other algorithms harder to write elegantly using availability domain
algebra. Instead, special case `*` in unavailability computations and only form
an availability domain lattice with the ABI stable platform domains,
`anyAppleOS`, and `Swift`.
Some Darwin platforms like DriverKit use a system prefix on all of their search paths. Even though DriverKit isn't supported, add support to get the system prefix from SDKSettings when constructing the default search paths.
This requires the DarwinSDKInfo to be gotten earlier in CompilerInvocation, pass that down to ASTContext through CompilerInstance.
-platform-availability-inheritance-map-path is no longer needed to support visionOS in tests, remove that and its supporting code that gets an alternative DarwinSDKInfo.
rdar://166277280
`anyAppleOS` represents a meta-platform for availability checks that can be
used to check availability across all of Apple's operating systems. It
supports versions 26.0 and up since version 26.0 is the first OS version number
that is aligned accross macOS, iOS, watchOS, tvOS, and visionOS.
Apple platform-specific availability specification take precedence over
`anyAppleOS` availability specifications when specified simultaneously.
Resolves rdar://153834380.
Availability version remapping currently only applies to code built for
visionOS. We plan to introduce more platform kinds and standalone availability
domains that will require version remapping, though, so it's time to
rearchitect and simplify the code to make it easier to generalize.
`AvailabilityDomain` is now responsible for version remapping and much of the
previously duplicated utilities have been consolidated.
Add support for the `Swift` availability domain, which represents availability
with respect to the Swift runtime. Use of this domain is restricted by the
experimental feature `SwiftRuntimeAvailability`.
A "permanently enabled" availability domain is one that has been declared
always available and is also simultaneously has either an attribute that
makes it deprecated or universally unavailable.
Emit fix-its that remove (or update) `@available` attributes that restrict
availability in a permanently enabled domain. Also, emit warnings about
`if #available` queries that always return true because they check a
permanently enabled domain.
Resolves rdar://157601761.
An always enabled availability domain is implicitly available in all contexts,
so uses of declarations that are marked as `@available` in the domain are never
rejected. This is useful for an availability domain representing a feature flag
that has become permanently enabled.
Partially resolves rdar://157593409.
When emitting statement diagnostics for `if #available` queries, diagnose the
availability of the decls representing the referenced availability domains.
Among other things, this checks that the domains are sufficiently visible to be
used in the containing function body context.
Cache the result of turning a `ValueDecl` into an `AvailabilityDomain`. Use
split caching to make the common case of the decl not representing an
availability domain efficient.
NFC.
When importing custom availability domains with dynamic predicates from Clang
modules, synthesize predicate functions for `if #available` queries and call
them when generating SIL.
Resolves rdar://138441312.
When the CustomAvailability experimental feature is enabled, make it an error
to specify an unrecognized availability domain name. Also, add these
diagnostics to a diagnostic group so that developers can control their behavior
when they are warnings.
Resolves rdar://152741624.
When compiling for visionOS, iOS availability attributes are remapped into the
visionOS availability domain automatically. While the version remapping was
being performed correctly, there was a regression that caused the platform name
to be printed incorrectly in many diagnostics. Whenever an iOS version is
remapped to a visionOS version, availability diagnostics will now present
those versions as visionOS versions instead of iOS versions.
Resolves rdar://146293165.
When serializing `@available` attributes, if the attribute applies to a custom
domain include enough information to deserialize the reference to that domain.
Resolves rdar://138441265.
https://github.com/swiftlang/swift/pull/79807 caused a regression in which
`AvailabilityContext` stopped tracking the available version range for the
active platform domain for certain platforms. Fix this by reverting to checking
`AvailabilityDomain::isActive()` to determine when a given platform
`AvailabilityDomain` represents the target platform. The compiler's existing
mapping from target triple to platform domain is incomplete and it's not clear
to me whether fixing that could cause other regressions.
Resolves rdar://147413616.
This is very brittle in this first iteration. For now we require the
declaration representing the availability domain be deserialized before it can
be looked up by name since Clang does not have a lookup table for availabilty
domains in its module representation. As a result, it only works for bridging
headers that are not precompiled.
Part of rdar://138441266.
Store `CustomAvailabilityDomain` instances in a folding set on `ASTContext`.
This instances of custom domains to be created without needing to cache them in
disparate locations.
Introduce a constructor that takes an `llvm::VersionTuple` directly, instead of
needing to spell out `VersionRange::allGTE(<tuple>)` which is unnecessarily
verbose.
Introduce `SemanticAvailableAttr` conveniences to compute the deprecated and
obsoleted ranges for an attribute and ensure they remap versions when needed.
Now that `AvailabilityContext` supports multiple unavailable domains, it's no
longer necessary to have a total ordering amongst the Swift,
PackageDescription, and Embedded availability domains.
This simplifies the code to emit availabilty diagnostics and ensures that they
display domain names consistently. While updating existing diagnostics, improve
consistency along other dimensions as well.
Delay resolution of availability domain identifiers parsed in availability
specifications until type-checking. This allows custom domain specifications to
be written in `if #available` queries.
This will unblock parsing and type-checking availability queries that specify
custom availability domains, e.g.:
```
if #available(CustomDomain) {
// Use declarations protected by @available(CustomDomain)
}
```
Implement lookup of availability domains for identifiers on
`AvailabilityDomainOrIdentifier`. Add a bit to that type which represents
whether or not lookup has already been attempted. This allows both
`AvailableAttr` and `AvailabilitySpec` to share a common implementation of
domain lookup.
One to get the active domain for the compilation target and another to get the
ABI compatibility domain for a given domain. The ABI compatibility domain will
be needed for queries that compute whether an unavailable declaration is still
reachable at runtime.
NFC.
This operation describes the partial ordering with which Availability domains
form a lattice.
As a temporary measure, a containment ordering needs to be specified for the
Swift language, Embedded, and Package Description domains. Without this
ordering, there won't be a way for AvailabilityContext to preserve the
invariant that the unavailable domain of a child context contains the
unavailable domain for the parent. However, once AvailabilityContext is
refactored to represent the status of multiple availability domains
simultaneously, the ordering of these domains relative to each other can be
relaxed.
NFC.
Represent an AvailabilityDomain as a pointer union where one member of the
union is inline storage for built-in domains with known requirements and the
other member of the union is a pointer to an externally allocated domain
definition.
NFC.
It was difficult to preserve the existing, buggy behavior of availability
attribute inference with respect to attributes specifying availability for
non-platform-specific domains. Instead, this change improves attribute merging
by tracking every domain independently, and only merging attributes from the
same domain.
Allan Shortlidge
Ian Anderson