Instead of visiting all members of all types and extensions, bail out
early if the type is not a class or protocol, or the extension is not
extending a class. This means we don't visit structs, enums or
protocol extensions at all, which will avoid delayed parsing.
Also, we were evaluating isObjC() on each member, which is an expensive
operation; if the member does not have an explicit @objc we would still
have to check if it overrides an @objc method or witnesses an @objc
protocol requirement.
Since most members are not ever found by dynamic lookup, this is wasted
work. Instead, let's rely on AnyObject lookup filtering non-@objc
members at the call site, which it was already doing anyway.
CSDiag could re-typecheck closure or other expression which has editor
placeholder inside allowing type variables be bound to unresolved
type, which doesn't really form a valid solution to be applied to AST.
So we need to guard against trying to transform placeholder into a call
to `_undefined` in such case, otherwise in asserts build it's going to
crash with an assert but in release build it would crash in some other
place e.g. xSILGen or trying to type-check captures.
Resolves: rdar://problem/48937223
Resolves: rdar://problem/51599529
When applying generic arguments to a local generic type within a generic
function, ensure that we correctly produce the contextual substitutions from
the generic function. Fixed with Pavel, who painstakingly tracked down
the bogus substitution.
Fixes SR-9954 / rdar://problem/48223824.
Check the availability of decls that declare an opaque return type to ensure they deploy to a
runtime that supports opaque types.
rdar://problem/50731151
Opaque result type archetypes can involve type variables, which
then get introduced into GenericSignatureBuilders and the
generated GenericSignatures. Allocate them in the proper arena
So we don’t end up with use-after-free errors.
Fixes rdar://problem/50309503.
Escapingness is a property of the type of a value, not a property of a function
parameter. Having it as a separate parameter flag just meant one more piece of
state that could get out of sync and cause weird problems.
Instead, always look at the noescape bit in a function type as the canonical
source of truth.
This does mean that '@escaping' is now printed in a few diagnostics where it was
not printed before; we can investigate these as separate issues, but it is
correct to print it there because the function types in question are, in fact,
escaping.
Fixes <https://bugs.swift.org/browse/SR-10256>, <rdar://problem/49522774>.
This is a defensive move to avoid duplicated work and guard against crashes
when a multi-expression closure body or TapExpr has not been type checked yet.
Fixes <rdar://problem/48852402>.
`openUnboundGenericType` eagerly tries to add conditional requirements
associated with chain of parents of the given type if type has been
declared inside of constrained extension. But one of the parent types
might be unbound e.g. `A.B` which means it has to be opened, which
by itself, would add such requirements.
Resolves: rdar://problem/49371608
