In anticipation of needing to compute runtime unavailability to determine
whether declarations should be printed in swiftinterfaces, factor out the code
that computes runtime unavailability into a shared utility based on
`DeclAvailabilityConstraints`.
NFC.
In implicit contexts that are universally unavailable, allow writable key paths
to be formed to properties with setters that are also marked as universally
unavailable. This fixes a regression from the previous commit where the code
synthesized for `@Observable` properties in universally unavailable classes was
rejected by the availability checker.
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.
Generalize the implementation of `SemanticDeclAvailabilityRequest` in
preparation for adding a new case to `SemanticDeclAvailability`. Use the
centralized availability constraint query instead of implementing a bespoke
algorithm for gathering constraints. Simplify `SemanticDeclAvailability` by
removing a case that is no longer relevant.
Part of rdar://138441307.
Choose names that don't imply availability is versioned, since custom
availability will support domains that are version-less (they are simply
available or unavailable).
When building up AvailabilityContexts, we assume that all of the enclosing
decls have already been accounted for in the AvailabilityContext that we are
constraining. Therefore, it doesn't make sense to merge availability
constraints from the enclosing extension of the target decl.
Switch to calling `swift::getAvailabilityConstraintsForDecl()` to get the
unsatisfied availability constraints that should be diagnosed.
This was intended to be NFC, but it turns out it fixed a bug in the recently
introduced objc_implementation_direct_to_storage.swift test. In the test,
the stored properties are as unavailable as the context that is accessing them
so the accesses should not be diagnosed. However, this test demonstrates a
bigger issue with `@objc @implementation`, which is that it allows the
implementations of Obj-C interfaces to be less available than the interface,
which effectively provides an availability checking loophole that can be used
to invoke unavailable code.
This new query is designed to become the canonical source of information
regarding whether a declaration is available to use in a given
`AvailabilityContext`. It should be adopted as the foundational building block
for all other queries that answer more specific questions about the
availability of a specific delcaration.
The implementation of this query has been copied from a variety of sources
which should eventually be deleted once the new query has been fully adopted.
NFC.
AvailabilityConstraint models a superset of UnavailabilityDiagnosticInfo and
will become the currency type for unsatisfied availability everywhere. NFC.
Put AvailabilityRange into its own header with very few dependencies so that it
can be included freely in other headers that need to use it as a complete type.
NFC.
