Now that the generic signature is computable on demand, this predicate is doubly useless. All of the callers intended to ask "hasInterfaceType" anyways.
The general class of cycle here is when validation asks for the generic signature which triggers requirement checking which forces us to ask for the generic signature of the extension again. We should look into a more principled solution.
See rdar://55263708
Computing the interface type of a typealias used to push validation forward and recompute the interface type on the fly. This was fragile and inconsistent with the way interface types are computed in the rest of the decls. Separate these two notions, and plumb through explicit interface type computations with the same "computeType" idiom. This will better allow us to identify the places where we have to force an interface type computation.
Also remove access to the underlying type loc. It's now just a cache location the underlying type request will use. Push a type repr accessor to the places that need it, and push the underlying type accessor for everywhere else. Getting the structural type is still preferred for pre-validated computations.
This required the resetting of a number of places where we were - in many cases tacitly - asking the question "does the interface type exist". This enables the removal of validateDeclForNameLookup
Define a request for computing the interface type of the underlying type of a typealias. This can be used in place of the declared interface type of the alias itself when it is nested to preserve the fragile validation ordering issues that can cause.
Define a request that provides the generic signature for a given generic context. This unblocks a ton of cleanup and will allow us to remove validateExtension, validateDeclForNameLookup, and a lot of the surrounding infrastructure.
Being more honest about which declarations actually have a generic signature computed has naturally introduced more cycles in requests. hasComputedGenericSignature() now acts as a recursion breaker. In the future, we should purge any uses of this accessor that specifically head-off cycles as the cycle itself is probably part of a larger structural problem.
First, remove the AvailabilityContext parameter; it was confusing because
we actually always want to use the deployment target here.
Then, split this method up into three methods:
- isAlwaysWeakImported(): simply checks for a @_weakLinked attribute, either
on the declaration itself or one of its parent contexts.
- getAvailabilityForLinkage(): returns the OS version availability when
this declaration was introduced, or if the declaration does not have
explicit availability, check it's storage (if its an accessor), or its
parent contexts.
- isWeakImported(ModuleDecl *fromModule): combines these two checks to
determine if the declaration should be weak linked when referenced from
the given module, or if it might be weak referenced from some module
(if the module parameter is null).
This eliminates the entire 'lazy generic environment' concept;
essentially, all generic environments are now lazy, and since
each signature has exactly one environment, their construction
no longer needs to be co-ordinated with deserialization.
This avoids a re-entrant lookup while doing lazy member loading,
and eliminates a usage of LookupDirectFlags::IgnoreNewExtensions,
and the last usage of NominalTypeDecl::makeMemberVisible().
Unify a bunch of quasi-independent callsites into a single request that
builds up a generic signature from a variety of inference sources. This
draws the extension typealias workaround for SE-0229 into TypeCheckDecl
where we can better work on refactoring it. The goal is to use this as
a springboard to requests that compute generic environments for various
and sundry decls.
Rework the lazy function body parsing mechanism to use the
request-evaluator, so that asking for the body of a function will
initiate parsing. Clean up a number of callers to
AbstractFunctionDecl::getBody() that don't actually need the body, so
we don't perform unnecessary parsing.
This change does not delay parsing of function bodies in the general
case; rather, it sets up the infrastructure to always delay parsing of
function bodies.
Rework the lazy function body parsing mechanism to use the
request-evaluator, so that asking for the body of a function will
initiate parsing. Clean up a number of callers to
AbstractFunctionDecl::getBody() that don't actually need the body, so
we don't perform unnecessary parsing.
This change does not delay parsing of function bodies in the general
case; rather, it sets up the infrastructure to always delay parsing of
function bodies.
Ensure that lazy parsing of the members of nominal type definitions
and extensions is handled through a request. Most of the effort here
is in establishing a new request zone for parser requests.
Introduce callables: values of types that declare `func callAsFunction`
methods can be called like functions. The call syntax is shorthand for
applying `func callAsFunction` methods.
```swift
struct Adder {
var base: Int
func callAsFunction(_ x: Int) -> Int {
return x + base
}
}
var adder = Adder(base: 3)
adder(10) // desugars to `adder.callAsFunction(10)`
```
`func callAsFunction` argument labels are required at call sites.
Multiple `func callAsFunction` methods on a single type are supported.
`mutating func callAsFunction` is supported.
SR-11378 tracks improving `callAsFunction` diagnostics.
