In theory this is a source break if someone had a weird custom
conforming type, but I suspect in practice conformances to
this protocol are never defined.
The reason we want this requirement is that often you will see
code like the following:
protocol Point {
associatedtype Scalar: SIMDScalar
associatedtype Vector: SIMD where Vector.Scalar == Scalar
}
extension Point where Vector == SIMD2<Scalar> { ... }
When `Vector` is equated with `SIMD2<Scalar>`, we get an infinite
sequence of implied same-type requirements:
Vector.MaskStorage == SIMD2<Scalar.MaskScalar>
Vector.MaskStorage.MaskStorage == SIMD2<Scalar.MaskScalar.MaskScalar>
...
The protocol fails to typecheck with an error because the requirement
machine cannot build a rewrite system.
If SIMDScalar requires that MaskScalar.MaskScalar == MaskScalar, then
we instead get
Vector.MaskStorage == SIMD2<Scalar.MaskScalar>
Vector.MaskStorage.MaskStorage == SIMD2<Scalar.MaskScalar>
Vector.MaskStorage.MaskStorage == Vector.MaskStorage
...
Which ties off the recursion.
In theory, a more advanced implementation could represent this kind of
infinite recursion in 'closed form', but we don't have that yet, and I
believe adding this same-type requirement makes sense anyway.
Fixes rdar://problem/95075552.
Adding `_runAsyncMain` to the api-digester list since we're adding
`@preconcurrency` when we add `@Sendable`. These two should negate each
other, but the api-digester isn't quite smart enough to understand that.
* Audit and correct AsyncSequence Sendability
* Annotate availability on Sendable conformances for AsyncSequences
* Fix typo of Sendable.Iterator
* Correct tests to use sendable builders
* Add @preconcurrency annotations and fixup one remaining missing @Sendable case
* Move preconcurrency to correct syntactical position
* Use unchecked Sendable conditional conformance instead of marking all internals as preconcurrency and sendable
* Use unchecked Sendable conditional conformance instead of marking all internals as preconcurrency and sendable for dropWhile
* claim ABI changes for marking of @preconcurrency as expected
ABI descriptors should always be emitted as sidecars for library-evolution-enabled modules.
However, generating these files requires traversing the entire module (like indexing), which may
hit additional deserialization issues. To unblock builds, this patch introduces a flag to skip
the traversing logic so that we emit an empty ABI descriptor file. The empty file serves as
a placeholder so that build system doesn't need to know the details.
Emitted at the emit-module step, ABI descriptor is of an entensible JSON format. This patch sets
up a segment in the file to also keep track of all compile-time constant values for other tools
to consume. As the initial step, we only keep track of string literals in the source files.
Unfortunately, we can't make this optimization work internally for now.
However, we can revisit it later. One strategy would be to emit the
witness as a private declaration, so that clients call it through the
witness table.
Fixes rdar://problem/86861522.
The first generic parameter of an `OpaqueTypeDecl` was still being used
as the "underlying" interface type of the opaque type, which is
incorrect for both structural and named opaque result types. Eliminate
this notion, because the (declared) interface type already has the
correct structure.
Only ABI checking depended on the old "underlying" type, so rework it to
instead substitute into properly for structural opaque result types as
well.
Deserialization required a small adjustment to eliminate a cycle
because the interface type of an `OpaqueTypeDecl` involves opaque
archetype types, which reference the declaration itself... so
deserialize the interface type later, now that it's correct.
Asynchronous functions isolated to global actors hop to the global at
the beginning of the function but do not hop back on return. For
`MainActor.run`, this means that we would not "hop back" off the main
actor after executing the closure, which lead to too much code running
on the main thread. Dropping the "async" ensures that we hop back.
While we my also want the general "hop back" semantics for
asynchronous actor-isolated functions, for now this addresses the
problem with `MainActor.run`.
Fixes rdar://82138050.
Previously, we use USR as a delegate for mangled name. However, USR won't incorporate name changes made
by attributes like @_silgen_name. Instead, we should add a dedicated field for canonical mangled names.
rdar://84202064
Previously, we use USR as a delegate for mangled name. However, USR won't incorporate name changes made
by attributes like @_silgen_name. Instead, we should add a dedicated field for canonical mangled names.
rdar://84202064
Add the generated ABI baseline for the _Concurency model on x86_64
macOS, along with a test that checks the built _Concurrency model
against that baseline.
Right now, the test is a mess, because we have some ABI breaks to
unwind. Add it so the test passes, and then we'll audit and address
every change.
Fixes rdar://83673282.
