When deriving `Hashable` and `Equatable` for enums, use
`Decl::isUnreachableAtRuntime()` to determine whether or not to insert
`_diagnoseUnavailableCodeReached()` traps for specific enum elements. This
fixes a bug where inappropriate traps were inserted for enum elements that are
unavailable for app extensions. It also fixes a bug where traps were inserted
when building a zippered library for macOS and enum elements were unavailable
on macOS but not for macCatalyst clients.
Resolves rdar://125371621
Introduce a predicate that determines when a given extension corresponds
to what one would get by existing the nominal type without spelling out
any constraints. This differs from the notion of a "constrained
extension" when the nominal type suppresses conformances on any of its
generic parameters, e.g.,
struct X<T: ~Copyable> { ... }
// doesn't spell out any constraints, but is constrained because it
// implicitly adds T: ~Copyable.
extension X { ... }
// does spell out constraints, but is not constrained because the
// generic signature matches that of X.
extension X where T: ~Copyable { }
Use this predicate when demangling a name to metadata, because name
mangling for extensions suppresses the generic signature for cases
where one "doesn't spell out any constraints."
Introduce metadata and runtime support for describing conformances to
"suppressible" protocols such as `Copyable`. The metadata changes occur
in several different places:
* Context descriptors gain a flag bit to indicate when the type itself has
suppressed one or more suppressible protocols (e.g., it is `~Copyable`).
When the bit is set, the context will have a trailing
`SuppressibleProtocolSet`, a 16-bit bitfield that records one bit for
each suppressed protocol. Types with no suppressed conformances will
leave the bit unset (so the metadata is unchanged), and older runtimes
don't look at the bit, so they will ignore the extra data.
* Generic context descriptors gain a flag bit to indicate when the type
has conditional conformances to suppressible protocols. When set,
there will be trailing metadata containing another
`SuppressibleProtocolSet` (a subset of the one in the main context
descriptor) indicating which suppressible protocols have conditional
conformances, followed by the actual lists of generic requirements
for each of the conditional conformances. Again, if there are no
conditional conformances to suppressible protocols, the bit won't be
set. Old runtimes ignore the bit and any trailing metadata.
* Generic requirements get a new "kind", which provides an ignored
protocol set (another `SuppressibleProtocolSet`) stating which
suppressible protocols should *not* be checked for the subject type
of the generic requirement. For example, this encodes a requirement
like `T: ~Copyable`. These generic requirements can occur anywhere
that there is a generic requirement list, e.g., conditional
conformances and extended existentials. Older runtimes handle unknown
generic requirement kinds by stating that the requirement isn't
satisfied.
Extend the runtime to perform checking of the suppressible
conformances on generic arguments as part of checking generic
requirements. This checking follows the defaults of the language, which
is that every generic argument must conform to each of the suppressible
protocols unless there is an explicit generic requirement that states
which suppressible protocols to ignore. Thus, a generic parameter list
`<T, Y where T: ~Escapable>` will check that `T` is `Copyable` but
not that it is `Escapable`, and check that `U` is both `Copyable` and
`Escapable`. To implement this, we collect the ignored protocol sets
from these suppressed requirements while processing the generic
requirements, then check all of the generic arguments against any
conformances not suppressed.
Answering the actual question "does `X` conform to `Copyable`?" (for
any suppressible protocol) looks at the context descriptor metadata to
answer the question, e.g.,
1. If there is no "suppressed protocol set", then the type conforms.
This covers types that haven't suppressed any conformances, including
all types that predate noncopyable generics.
2. If the suppressed protocol set doesn't contain `Copyable`, then the
type conforms.
3. If the type is generic and has a conditional conformance to
`Copyable`, evaluate the generic requirements for that conditional
conformance to answer whether it conforms.
The procedure above handles the bits of a `SuppressibleProtocolSet`
opaquely, with no mapping down to specific protocols. Therefore, the
same implementation will work even with future suppressible protocols,
including back deployment.
The end result of this is that we can dynamically evaluate conditional
conformances to protocols that depend on conformances to suppressible
protocols.
Implements rdar://123466649.
we only check if the loaded module is built from a package interface. This is
not enough as a binary module could just contain exportable decls if built with
experimental-skip-non-exportable-decls, essentially resulting in content equivalent
to interface content. This might be made a default behavior so this PR requires
a module to opt in to allow non-resilient access by a participating client in the
same package.
Since it affects module format, SWIFTMODULE_VERSION_MINOR is updated.
rdar://123651270
isResilient(ModuleDecl, ResilienceExpansion).
isResilient() returns the decl's resilience by definition
and should not be altered whether bypassing optimization
is enabled or not. The overloaded isResilient(ModuleDecl..)
is used for accessing a decl from a client module, which is
the appropriate place to opt in for non-resilience in package.
Resolves rdar://123031292
When determining whether a declaration should be considered unavailable at
runtime, ignore `@available` attributes for application extension platforms but
continue searching for other `@available` attributes that might still make the
declaration unavailable. This ensures corner cases like these are handled:
```
// Dubious, but allowed
@available(macOS, unavailable)
@available(macOSApplicationExtension, unavailable)
public func doublyUnavailableOnMacOSFunc() {}
// Expresses an uncommon, but valid constraint
@available(macCatalyst, unavailable)
@available(iOSApplicationExtension, unavailable)
public func confusingDiamondAvailabilityInheritanceFunc() {}
```
[transferring] Implement transferring result and clean up transferring param support by making transferring a bit on param instead of a ParamSpecifier.
Instead it is a bit on ParamDecl and SILParameterInfo. I preserve the consuming
behavior by making it so that the type checker changes the ParamSpecifier to
ImplicitlyCopyableConsuming if we have a default param specifier and
transferring is set. NOTE: The user can never write ImplicitlyCopyableConsuming.
NOTE: I had to expand the amount of flags that can be stored in ParamDecl so I
stole bits from TypeRepr and added some logic for packing option bits into
TyRepr and DefaultValue.
rdar://121324715
The reason why I am doing this is that I am going to be changing transferring to
not be a true ParamSpecifier. Instead, it is going to be a bit on Param that
changes the default ParamSpecifier used. That being said, I cannot use consuming
for this purpose since consuming today implies no implicit copy semantics, which
we do not want unless the user specifically asks for it by writing consuming.
By default package decls are treated as resilient, similar to public (non-frozen).
This PR adds support to allow direct access to package decls at use site if opted-in.
Requires the loaded module to be a binary module in the same package.
Resolves rdar://121626315
An @_objcImpl extension with no category name *should* implement not only the class’s main @interface, but also any class extension @interfaces. Start making this true by making ObjCInterfaceAndImplementationRequest return all of these decls as the interfaces for such an implementation.
This commit doesn’t actually change Sema or IRGen to process the extra interfaces, so it’s NFC.
This reduces the memory overhead of objcImpl from one word per Decl to one bit per Decl, at the cost of making cache lookups slightly slower (but it will only be consulted once for non-objcImpl decls, which is by far the most common case).
