As part of this, lift the now-unnecessary restriction against
combining a non-mutable addressor with a setter. I've also
tweaked some of the diagnostics.
This is in preparation for generalized accessors.
By formalizing ReferenceOwnership as a diagnostic argument kind, we get
less boilerplate, better type safety, better output consistency, and
last but not least: future proofing.
When performing a binding/assignment to a weak or unowned variable/property from an initialiser call, emit a warning that the instance will be immediately deallocated.
The Swift class model does not support overriding declarations where either
the overridden declaration or the overriding declaration are in an extension.
However, the Objective-C class model does, so marking the declaration as
@objc (when possible) will work around the limitation.
Customize the "cannot override declaration in extension" diagnostic to
suggest adding @objc to the overridden declaration in cases where
@objc is permitted. Fixes SR-6512 / rdar://problem/35787914.
Conditional conformances aren't quite ready yet for Swift 4.1, so
introduce the flag `-enable-experimental-conditional-conformances` to
enable conditional conformaces, and an error when one declares a
conditional conformance without specifying the flag.
Add this flag when building the standard library (which will vend
conditional conformances) and to all of the tests that need it.
Fixes rdar://problem/35728337.
* [SR-5856] Fix diagnostic message for static stored properties not supported in protocol extensions
* fix test failure in decl/var/properties.swift
this looks like a better place to test the new behavior, so removing changes to static_var.swift
This eliminates the need for an ugly and incomplete hack to suppress
noescape inference for setter arguments. It also means we stop emitting
redundant diagnostics for problems in storage types.
We don't actually need the TypeLoc for anything, but it was still
getting type-checked, which means it doesn't get the benefit of
inference from the initial value. In some cases the actual type of the
ParamDecl seems to get reset to the TypeLoc's type as well. Just do
the simple thing and set it directly ahead of time.
Fixes a source compatibility issue with Swift 3.0.
https://bugs.swift.org/browse/SR-3893
`1 { }` was parsed as a call expression with a trailing closure. This made the diagnostics for `var x = 1 { get { ... } }` extremely bad. Resolves SR-3671.
We cannot properly determine the context type of any parameter
(including 'self') until after we have determined the generic
environment for the enclosing function.
* [Fixit] Add a fixit for converting non-trailing closures to trailing closures.
* [test] Update test to reflect the added note about converting to trailing closures.
Parse 'var [behavior] x: T', and when we see it, try to instantiate the property's
implementation in terms of the given behavior. To start out, behaviors are modeled
as protocols. If the protocol follows this pattern:
```
protocol behavior {
associatedtype Value
}
extension behavior {
var value: Value { ... }
}
```
then the property is instantiated by forming a conformance to `behavior` where
`Self` is bound to the enclosing type and `Value` is bound to the property's
declared type, and invoking the accessors of the `value` implementation:
```
struct Foo {
var [behavior] foo: Int
}
/* behaves like */
extension Foo: private behavior {
@implements(behavior.Value)
private typealias `[behavior].Value` = Int
var foo: Int {
get { return value }
set { value = newValue }
}
}
```
If the protocol requires a `storage` member, and provides an `initStorage` method
to provide an initial value to the storage:
```
protocol storageBehavior {
associatedtype Value
var storage: Something<Value> { ... }
}
extension storageBehavior {
var value: Value { ... }
static func initStorage() -> Something<Value> { ... }
}
```
then a stored property of the appropriate type is instantiated to witness the
requirement, using `initStorage` to initialize:
```
struct Foo {
var [storageBehavior] foo: Int
}
/* behaves like */
extension Foo: private storageBehavior {
@implements(storageBehavior.Value)
private typealias `[storageBehavior].Value` = Int
@implements(storageBehavior.storage)
private var `[storageBehavior].storage`: Something<Int> = initStorage()
var foo: Int {
get { return value }
set { value = newValue }
}
}
```
In either case, the `value` and `storage` properties should support any combination
of get-only/settable and mutating/nonmutating modifiers. The instantiated property
follows the settability and mutating-ness of the `value` implementation. The
protocol can also impose requirements on the `Self` and `Value` types.
Bells and whistles such as initializer expressions, accessors,
out-of-line initialization, etc. are not implemented. Additionally, behaviors
that instantiate storage are currently only supported on instance properties.
This also hasn't been tested past sema yet; SIL and IRGen will likely expose
additional issues.
