If there are any conversion restrictions present while trying to repair
failures related to contextual type, let's give `simplifyRestrictedConstraintImpl`
a chance to run and fix the problem.
Resolves: rdar://problem/59773317
When there is a conversion from e.g. `(A) -> Void` to `(B) -> Void`
matching between `A` and `B` is going to have a special locator which
doesn't end in `TupleElement`, so `repairFailures` has to account
for that and fix it just like regular argument mismatch.
Resolves: rdar://problem/59066040
Originally type mismatches associated with conversions between
function types were only covered for coercions and assignments
but fix coverage grew since then and now it makes sense
to remove special case and let `repairFailures` take care of it.
Currently single parameter tuple splat fix/diagnostic supports only
cases where parameter is a concrete tuple type, let's enhance that to
support generic parameters as well e.g.:
```swift
func foo<T>(_: T) {}
foo(0, 1, 2) // `T` expects arguments to form a tuple e.g. `foo((0, 1, 2))`
```
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>.
Cases with arguments form `(Self.Type) -> (Arg...) -> Self`
function types, so `areConservativelyCompatibleArgumentLabels`
should remove curried self before trying to match argument/parameter
labels.
Resolves: rdar://problem/49159472
Try to fix constraint system in a way where member
reference is going to be defined in terms of its use,
which makes it seem like parameters match arguments
exactly. Such helps to produce solutions and diagnose
failures related to missing members precisely.
These changes would be further extended to diagnose use
of unavailable members and other structural member failures.
Resolves: rdar://problem/34583132
Resolves: rdar://problem/36989788
Resolved: rdar://problem/39586166
Resolves: rdar://problem/40537782
Resolves: rdar://problem/46211109
When trying to diagnose problems related to calls where
function is represented by a member of nominal type let's
attempt to be more cautious while type-checking function
expression without it's arguments, because it could produce
unrelated diagnostics.
Resolves: rdar://problem/32551313, rdar://problem/28456467, rdar://problem/31671195
Enum elements have to be treated the same way as regular functions
when passed as values, which means labels have to be stripped from
their argument types.
Resolves: rdar://problem/32300339.
