Add `async` to the type system. `async` can be written as part of a
function type or function declaration, following the parameter list, e.g.,
func doSomeWork() async { ... }
`async` functions are distinct from non-`async` functions and there
are no conversions amongst them. At present, `async` functions do not
*do* anything, but this commit fully supports them as a distinct kind
of function throughout:
* Parsing of `async`
* AST representation of `async` in declarations and types
* Syntactic type representation of `async`
* (De-/re-)mangling of function types involving 'async'
* Runtime type representation and reconstruction of function types
involving `async`.
* Dynamic casting restrictions for `async` function types
* (De-)serialization of `async` function types
* Disabling overriding, witness matching, and conversions with
differing `async`
The new function swift_getCanonicalSpecializedMetadata takes a metadata
request, a prespecialized non-canonical metadata, and a cache as its
arguments. The idea of the function is either to bless the provided
prespecialized metadata as canonical if there is not currently a
canonical metadata record for the type it describes or else to return
the actual canonical metadata.
When called, the metadata cache checks for a preexisting entry for this
metadata. If none is found, the passed-in prespecialized metadata is
added to the cache. Otherwise, the metadata record found in the cache
is returned.
rdar://problem/56995359
Two protocol conformance descriptors are passed to
swift_compareProtocolConformanceDecriptors from generic metadata
accessors when there is a canonical prespecialization and one of the
generic arguments has a protocol requirement.
Previously, the descriptors were incorrectly being passed without
ptrauth processing: one from the witness table in the arguments that are
passed in to the accessor and one known statically.
Here, the descriptor in the witness table is authed using the
ProtocolConformanceDescriptor schema. Then, both descriptors are signed
using the ProtocolConformanceDescriptorsAsArguments schema. Finally, in
the runtime function, the descriptors are authed.
This simply uses the qualified names for `StringRef` and `Optional` to
help with use of regular expressions to identify the usage to help
migrate the references away from `LLVMSupport` to enable explicitly
vending a custom `LLVMSupport` in the runtime.
When generic metadata for a class is requested in the same module where
the class is defined, rather than a call to the generic metadata
accessor or to a variant of typeForMangledNode, a call to a new
accessor--a canonical specialized generic metadata accessor--is emitted.
The new function is defined schematically as follows:
MetadataResponse `canonical specialized metadata accessor for C<K>`(MetadataRequest request) {
(void)`canonical specialized metadata accessor for superclass(C<K>)`(::Complete)
(void)`canonical specialized metadata accessor for generic_argument_class(C<K>, 1)`(::Complete)
...
(void)`canonical specialized metadata accessor for generic_argument_class(C<K>, count)`(::Complete)
auto *metadata = objc_opt_self(`canonical specialized metadata for C<K>`);
return {metadata, MetadataState::Complete};
}
where generic_argument_class(C<K>, N) denotes the Nth generic argument
which is both (1) itself a specialized generic type and is also (2) a
class. These calls to the specialized metadata accessors for these
related types ensure that all generic class types are registered with
the Objective-C runtime.
To enable these new canonical specialized generic metadata accessors,
metadata for generic classes is prespecialized as needed. So are the
metaclasses and the corresponding rodata.
Previously, the lazy objc naming hook was registered during process
execution when the first generic class metadata was instantiated. Since
that instantiation may occur "before process launch" (i.e. if the
generic metadata is prespecialized), the lazy naming hook is now
installed at process launch.
This removes the last reference to the `llvm::` namespace in the
standard library. All uses of the LLVMSupport library now are
namespaced into the `__swift::__runtime` namespace. This allows us to
incrementally vend the LLVMSupport library and make the separation
explicit.
There are a set of headers shared between the Swift compiler and the
runtime. Ensure that we explicitly use `llvm::ArrayRef` rather than
`ArrayRef` which is aliased to `::llvm::ArrayRef`. Doing so enables us
to replace the `ArrayRef` with an inline namespaced version fixing ODR
violations when the swift runtime is loaded into an address space with
LLVM.
The Objective-C runtime expects a signed pointer here. The existing test
would have caught this, except it was always disabled because the
symbol name passed to the dlsym() check should not have had the leading
'_'.
Fixes <rdar://problem/57679510>.
In preparation for the prespecialization of metadata for generic
classes, make checkMetadataState always return that the state of
prespecialized class metadata is complete, as is done for generic
structs and enums already.
Add mangling scheme for `@differentiable` and `@differentiable(linear)` function
types. Mangling support is important for debug information, among other things.
Update docs and add tests.
Resolves TF-948.
Extracted implementation of SpecializedGenericStructMetadataBuilder into
SpecializedGenericNominalMetadataBuilderBase, a CRTP with a template
template argument for the CRTP superclass and a template argument for
the implementation. That new type is now subclassed by
SpecializedGenericStructMetadataBuilder. Additionally, this new type is
also subclassed by the newly added SpecializedGenericEnumMetadataBuilder
which is responsible for build the prespecialization of generic enum
metadata.
rdar://problem/56960887
SR-3871: Dynamic casting of existentials stored in Obj-C references
Arbitrary Swift objects get packaged into __SwiftValue containers so
that pointers to them can be passed into Obj-C. (Obviously, Obj-C
code can't do anything particularly useful with such pointers other
than refcount them and give them back to Swift code.) Those values come
back into Swift as either `Any` (existential box) or `AnyObject`
(anonymous object pointer) values. Dynamically casting those requires
first inspecting the outer value to get access to the actual type and
value in the __SwiftValue container.
The tryDynamicCastBoxedSwiftValue() function that handles this
was missing a check for the `Any` case, which is why directly
casting from `Any` would routinely fail.
Resolves SR-3871
Added a new flag to the GenericMetadataPatternFlags flagset for whether
the metadata has a set of flags at its tail. When that flag is set,
there will be an extra uint64_t flagset at the end of the metadata. For
struct metadata, the type of that flagset will be
StructMetadataTrailingFlags. The first flag in that trailing flagset
indicates whether the metadata was statically specialized. The second
flag in that trailing flagset indicates whether the metadata is
statically canonical.
When verifying the metadata cache, a check is done for whether the
metadata was statically specialized and whether it was known to be
canonical statically. If so, verification is skipped. Skipping it is
necessary because the known-canonical statically specialized metadata
will not be in the cache. In that case, the canonical statically
specialized metadata will be returned from the metadata accessor and
never be cached.
SR-5289: Teach Mirror how to inspect weak, unowned, and unmanaged refs
Correctly reflect weak, unowned, and unmanaged references
to both Swift and Obj-C types (including existential references to
such types) that occur in both Swift class objects and in Swift
structs.
This includes the specific reported case (unowned reference to an
Obj-C object) and several related ones.
Related changes in this PR:
* Tweak internal bitmap used for tracking ownership modifiers
to reject unsupported combinations.
* Move FieldType into ReflectionMirror.mm
FieldType is really just an internal implementation detail
of this one source file, so it does not belong in an ABI header.
* Use TypeReferenceOwnership directly to track field ownership
This avoids bitwise copying of properties and localizes some
of the knowledge about reference ownership
* Generate a top-level "copyFieldContents" from ReferenceStorage.def
Adding new ownership types to ReferenceStorage.def will now
automatically produce calls to `copy*FieldContents` - failure
to provide a suitable implementation will fail the build.
* Add `deallocateBoxForExistentialIn` to match `allocateBoxForExistentialIn`
Caveat: The unit tests are not as strict as I'd like. Attempting to make them
so ran afoul of otherwise-unrelated bugs in dynamic casting.
* SR-5289: Support reflecting weak, unowned, and unmanaged refs
This refactors how we handle reference ownership
when reflecting fields of struct and class objects.
There are now explicit paths for each type of reference
and some simple exhaustiveness checks to fail the build
if a new reference type is added in the future without
updating this logic.
Add code to the 5.0 compatibility library that scans for conformances pointing to a NULL type and rewrites them to point to a dummy type that the 5.0 protocol conformance checking code will safely ignore.
