In #69257, we modified `ObjCReason` to carry a pointer to the @implementation attribute for the `MemberOfObjCImplementationExtension` kind. This made it mark the @implementation attribute as invalid, suppressing diagnostics from the ObjCImplementationChecker.
However, invalidating the attribute *also* causes it to be skipped by serialization. That isn’t a problem if the diagnostics are errors, since we’ll never emit the serialized module, but #74135 softened these diagnostics to warnings for early adopters.
The upshot was that if Swift emitted one of these warnings when it compiled a library, clients of that library would see the objcImpl extension as a normal extension instead. This would cause various kinds of mischief: ambiguous name lookups because implementations weren’t being excluded, overrides failing because an implementation was `public` instead of `open`, asserts and crashes in SILGen and IRGen because stored properties were found in seemingly normal extensions, etc.
Fix this by setting a separate bit on ObjCImplementationAttr, rather than the invalid bit, and modifying the implementation checker to manually suppress many diagnostics when that bit is set.
Fixes rdar://134730183.
Previously, the opaque types in patterns were printed using their full stable
reference which cannot be resolved when parsing a swiftinterface.
Resolves rdar://127771885.
Preserve the warning to use `internal import` instead of `@_implementationOnly`
to imports of Swift modules only. This warning can be noisy, limiting it may
prevent users from outright learning to ignore it. Typical uses of an
`@_implementationOnly` import of a clang module is often for a project
internal module instead of a layering concern as we have with Swift module
targets. We can leave legacy uses of `@_implementationOnly` in peace for now.
The warnings about `using '@_implementationOnly' without enabling library evolution for 'client'
may lead to instability during execution` and `@_implementationOnly' is deprecated, use
'internal import' instead` were wrongly restricted to only Swift import targets.
Make sure they are raised for clang module targets as well.
rdar://135233043
Some requirement machine work
Rename requirement to Value
Rename more things to Value
Fix integer checking for requirement
some docs and parser changes
Minor fixes
This expands the downgrade for Objective-C requirements to all requirements
until strict concurrency checking is enabled (either via a flag in Swift 5
language mode or by switching to Swift 6 language mode).
Resolves: rdar://134503878
For the purposes of availability calculations, direct use of
`llvm::VersionTuple` and `VersionRange` is discouraged, since these fundamental
version representations are divorced from their context. For example, comparing
an iOS platform version to a visionOS platform version is invalid since the
versioning systems of the two platforms differ. Although visionOS inherits
avialability from iOS, an iOS version must be converted to a visionOS version
prior to comparison. In the future, `AvailabilityContext` can be enriched to
carry the information necessary to verify that its algebraic operations are
being performed on compatible values.
NFC.
`UnavailabilityReason` does not live up to its name because it only models
potential unavailability due to an unmet OS version requirement. It does not
model unavailability caused by explicit annotation, language mode requirements,
obsoletion, etc. `AvailabilityContext` already models an OS version
requirement, so use it instead.
NFC.
An `AvailabilityContext` represents an abstract version range in which
something is available. In the future, these version ranges may not necessarily
always correspond to operating system version ranges.
NFC.
