Add constraint fix `AllowAutoClosurePointerConversion` and corresponding diagnostic
`AutoClosurePointerConversionFailure`. When we discover that we're trying to do an
inout-to-pointer conversion in `matchTypes`, add the constraint fix, which tries to do the
conversion as if the pointer type is a regular function argument.
Since all of the specific diagnostics which constitute requirement
failure now operate on types, their interfaces could be simplified
and associated requirement types could be stored in RequirementFailure.
Each candidate with incorrect labels (but everything else lined up)
gets a note on its declarationm which says what is expected and what
has been given.
Diagnose situation when a single "tuple" parameter is given N arguments e.g.
```swift
func foo<T>(_ x: (T, Bool)) {}
foo(1, false) // foo exptects a single argument of tuple type `(1, false)`
```
Additionally, refactor some of the logic for the original add $ diagnostic
so that a lot of logic can be shared between the two. Also rename the
original fix and diagnostic to better reflect their purpose.
Introduce a fix to detect and diagnose situations when omitted
generic arguments couldn't be deduced by the solver based on
the enclosing context.
Example:
```swift
struct S<T> {
}
_ = S() // There is not enough context to deduce `T`
```
Resolves: rdar://problem/51203824
Emit separate notes for generic parameters found in operator, initializer
and function declarations. As well as clarify types of `declared in type`
note.
All places where `invalid member ref` fix/diagnostic is used already
have a reference to the potential member choice declaration, which
diagnostic could take advantage of.
This is useful for `CSDiag` when it detects that all
overload choices have the same problem. Since there
are going to be no solutions, choice declaration could
be supplied to `invalid ref` diagnostic directly.
Resolves: rdar://problem/50467583
Resolves: rdar://problem/50682022
Resolves: rdar://problem/50909555
Extend use of `missing protocol conformance` fix to cover contextual
failures, such as:
- Assignment mismatches, where destination requires source to conform
to certain protocol (or protocol composition);
- Incorrect returns where returned type doesn't conform to the
protocol specified in the signature.
This commit adds `ConstraintSystem::getCalleeLocator`, which forms a
locator that describes the callee of a given expression. This function
is then used to replace various places where this logic is duplicated.
This commit also changes the conditions under which a ConstructorMember
callee locator is formed. Previously it was formed for a CallExpr with a
TypeExpr function expr. However, now such a locator is formed if the
function expr is of AnyMetatypeType. This allows it to be more lenient
with invalid code, as well as work with DotSelfExpr.
Resolves SR-10694.
Extend use of `missing protocol conformance` fix to cover contextual
failures, such as:
- Assignment mismatches, where destination requires source to conform
to certain protocol (or protocol composition);
- Incorrect returns where returned type doesn't conform to the
protocol specified in the signature.
