One of the request triggers added to `ConformanceLookupTable` in
https://github.com/apple/swift/pull/68384 can cause circular request
evaluation. Revert the request trigger since it doesn't appear to be necessary
for the test cases introduced in that PR.
Resolves rdar://115314044
Previously, conformances inherited through a base class could be missed in lazy
typechecking mode if types in the inheritance clause were not already resolved.
Provide member macros with similar information about conformances to
what extension macros receive, allowing member macros to document
which conformances they care about (e.g., Decodable) and then
receiving the list of conformances that aren't already available for
the type in question. For example, a macro such as
@attached(member, conformances: Decodable, Encodable, names:
named(init(from:), encode(to:)))
macro Codable() = ...
Expanded on a type that is not already Decodable/Encodable would be
provided with Decodable and Encodable (via the new
`missingConformancesTo:` argument to the macro implementation) when
the type itself does not conform to those types.
Member macros still cannot produce conformances, so this is likely to
be used in conjunction with extension macros most of the time. The
extension macro declares the conformance, and can also declare any
members that shouldn't be part of the primary type definition---such
as initializers that shouldn't suppress the memberwise initializer. On
the other hand, the member macro will need to define any members that
must be in the primary definition, such as required initializers,
members that must be overridable by subclasses, and stored properties.
Codable synthesis is an example that benefits from member macros with
conformances, because for classes it wants to introduce a required
initializer for decoding and an overridable encode operation, and
these must be members of the nominal type itself. Specifically, the
`Codable` macro above is likely to have two attached member roles:
@attached(member, conformances: Decodable, Encodable, names:
named(init(from:), encode(to:)))
@attached(extension, conformances: Decodable, Encodable, names:
named(init(from:), encode(to:)))
macro Codable() = ...
where the "extension" role is responsible for defining the conformance
(always), and the "member" creates the appropriate members for classes
(`init` vs. `required init`).
Tracked by rdar://112532829.
Wrap the `InheritedEntry` array available on both `ExtensionDecl` and
`TypeDecl` in a new `InheritedTypes` class. This class will provide shared
conveniences for working with inherited type clauses. NFC.
Fix two inter-related issues with extension macros that provide
conformances to a protocol, the combined effect of which is that one
cannot meaningfully provide extension macros that implement
conformances to a protocol like Equatable or Hashable that also
supports auto-synthesis.
The first issue involves name lookup of operators provided by macro
expansions. The logic for performing qualified lookup in addition to
unqualified lookup (for operators) did not account for extension
macros in the same manner as it did for member macros, so we would not
find a macro-produced operator (such as operator==) in witness
matching.
The second issue is more fundamental, which is that the conformance
lookup table would create `NormalProtocolConformance` instances for
pre-macro-expansion conformance entries, even though these should
always have been superseded by explicit conformances within the macro
expansion buffers. The end result is that we could end up with two
`NormalProtocolConformance` records for the same conformance. Some
code was taught to ignore the pre-expansion placeholder conformances,
other code was not. Instead, we now refuse to create a
`NormalProtocolConformance` for the pre-expansion entries, and remove
all of the special-case checks for this, so we always using the
superseding explicit conformances produced by the macro expansions (or
error if the macros don't produce them).
Fixes rdar://113994346 / https://github.com/apple/swift/issues/66348
stated in the original source.
If an extension macro can introduce protocol conformances, macro expansion
will check which of those protocols already have a stated conformance in the
original source. The protocols that don't will be passed as arguments to
extension macro expansion, indicating to the macro that it should only add
conformances to those protocols.
The conformance lookup table is the central point of truth to
establish which protocols a nominal type conforms to. Ensure that we
expand conformance macros into that table.
Fixes rdar://106886651.
Remove the allowUnavailable parameter to lookupConformance(), and instead
explicitly check the result for hasUnavailableConformance() in the places
where we used to pass 'false'.
Also, narrow down this check in those places to the Sendable protocol
only, fixing a regression with Hashable conformance synthesis.
Fixes rdar://problem/94460143.
When a class has an unavailable conformance to a protocol, do not
inherit that unavailable conformance, because it can get in the way of
subclasses defining their own (properly-available) conformance.
Fixes rdar://89992569.
A recent change to `Sendable` conformance handling resulted in subclasses of global-actor-confined classes being rejected if they explicitly declared a conformance to `Sendable`.
This behavior is technically correct because actor-isolated types are implicitly `Sendable`, but the source compatibility regression was not desirable. We are also considering requiring subclasses to explicitly repeat their superclass's `Sendable` conformance, so it makes sense to allow these redundant conformances in the general case to ease that potential transition.
Fixes rdar://88700507.
Many, many, many types in the Swift compiler are intended to only be allocated in the ASTContext. We have previously implemented this by writing several `operator new` and `operator delete` implementations into these types. Factor those out into a new base class instead.
Implicit synthesis of `Sendable` conformances for global actor-isolated
class types interacts poorly with the conformance lookup table's
attempt at modeling inherited conformances, so a `Sendable` conformance
will get created and inherited, but is then "missing" when we try to
form the actual inherited conformance.
The proper fix for this issue is likely to eliminate the modeling of
inherited conformances within the conformance lookup table, which
introduces a lot of redundance and, apparently, some bugs. For now,
patch over the issue to work around a crash.
Narrowly works around rdar://81700570.
It's been quite a long time since this unused parameter was introduced.
The intent is to produce the module as a root for the search - that is,
computing the set of conformances visible from that module, not the set
of conformances inside of that module. Callers have since been providing
all manner of module-scoped contexts to it.
Let's just get rid of it. When we want to teach protocol conformance
lookup to do this, we can revert this commit as a starting point and try
again.
Parse and provide semantic checking for '@unchecked Sendable', for a
Sendable conformance that doesn't perform additional semantic checks
for correctness.
Part of rdar://78269000.
If a conformance is found in an imported module as well as the current module,
and one of the two conformances is conditionally unavailable on the current
deployment target, pick the one that is always available.
Fixes <rdar://problem/78633800>.
The uncached, rarely-used getLocalProtocols() does not benefit from
having its own distinct implementation. Reimplement it on top of
getLocalConformances() to simplify things and benefit from the
request-evaluator infrastructure.
By convention, most structs and classes in the Swift compiler include a `dump()` method which prints debugging information. This method is meant to be called only from the debugger, but this means they’re often unused and may be eliminated from optimized binaries. On the other hand, some parts of the compiler call `dump()` methods directly despite them being intended as a pure debugging aid. clang supports attributes which can be used to avoid these problems, but they’re used very inconsistently across the compiler.
This commit adds `SWIFT_DEBUG_DUMP` and `SWIFT_DEBUG_DUMPER(<name>(<params>))` macros to declare `dump()` methods with the appropriate set of attributes and adopts this macro throughout the frontend. It does not pervasively adopt this macro in SILGen, SILOptimizer, or IRGen; these components use `dump()` methods in a different way where they’re frequently called from debugging code. Nor does it adopt it in runtime components like swiftRuntime and swiftReflection, because I’m a bit worried about size.
Despite the large number of files and lines affected, this change is NFC.
ProtocolConformanceRef already has an invalid state. Drop all of the
uses of Optional<ProtocolConformanceRef> and just use
ProtocolConformanceRef::forInvalid() to represent it. Mechanically
translate all of the callers and callsites to use this new
representation.
Push the relevant work this was doing down into the callers. Most of them didn't want to validate the entire extension and force its generic parameters, they just wanted to validate the nominal type.
We must eagerly validate the generic signature of extensions, though. This avoids a class of cycles where non-generic members of an extension with a generic signaure will call through to getGenericSignatureOfContext and force the generic signature anyways. When this calls through to protocol witness matching, the signature can be recursively computed.
Like the last commit, SourceFile is used a lot by Parse and Sema, but
less so by the ClangImporter and (de)Serialization. Split it out to
cut down on recompilation times when something changes.
This commit does /not/ split the implementation of SourceFile out of
Module.cpp, which is where most of it lives. That might also be a
reasonable change, but the reason I was reluctant to is because a
number of SourceFile members correspond to the entry points in
ModuleDecl. Someone else can pick this up later if they decide it's a
good idea.
No functionality change.
Most of AST, Parse, and Sema deal with FileUnits regularly, but SIL
and IRGen certainly don't. Split FileUnit out into its own header to
cut down on recompilation times when something changes.
No functionality change.
These can be recreated if needed in a client library. To do this, I've
added a new ConformanceLookupKind::NonInherited, which can also be
used elsewhere in the project where we're already filtering out
inherited conformances some other way.
Note that this doesn't drop inherited conformances from the entire
serialized interface, just from the list that a class explicitly
declares. They still get referenced sometimes.
rdar://problem/50541451 and possibly others
