This is necessary because:
```
func foo() -> some P
func foo() -> some P
```
theoretically defines two distinct return types, but there'd be no way to disambiguate them. Disallow overloading only by opaque return type.
The initialization of an instance property that has an attached
property delegate involves the initial value written on the property
declaration, the implicit memberwise initializer, and the default
arguments to the implicit memberwise initializer. Implement SILGen
support for each of these cases.
There is a small semantic change to the creation of the implicit
memberwise initializer due to SE-0242 (default arguments for the
memberwise initializer). Specifically, the memberwise initializer will
use the original property type for the parameter to memberwise
initializer when either of the following is true:
- The corresponding property has an initial value specified with the
`=` syntax, e.g., `@Lazy var i = 17`, or
- The corresponding property has no initial value, but the property
delegate type has an `init(initialValue:)`.
The specific case that changed is when a property has an initial value
specified as a direct initialization of the delegate *and* the
property delegate type has an `init(initialValue:)`, e.g.,
```swift
struct X {
@Lazy(closure: { ... })
var i: Int
}
```
Previously, this would have synthesized an initializer:
```swift
init(i: Int = ???) { ... }
```
However, there is no way for the initialization specified within the
declaration of i to be expressed via the default argument. Now, it
synthesizes an initializer:
```swift
init(i: Lazy<Int> = Lazy(closure: { ... }))
```
When a property has an attached property delegate, a backing storage
property of the corresponding delegate type will be
synthesized. Perform this synthesis, and also synthesize the
getter/setter for the original property to reference the backing
storage property.
The initializer associated with a lazy property should not be executed
directly, because it is subsumed by code synthesized into the
getter. Generalize the terminology here so we can re-use this path for
property delegate initialization.
A property with an attached delegate can be initialized in one of two ways:
* By directly specifying initialization arguments on the attribute,
e.g., "@SomeDelegate(x: 17, y: 42) var a".
* By initializing the original property itself, which goes through the
delegate type's init(initialValue:) initializer, e.g.,
"@Lazy var x = 17".
Implement support for both forms of initialization, including type
inference and checking for inconsistencies (e.g., if the annotation on
the property type doesn't match what the delegate type would
provide).
A custom attribute can be resolved to a property delegate type. Allow
this for property declarations (only), and diagnose the various places
where properties cannot have property delegates.
To represent the abstracted interface of an opaque type, we need a generic signature that refines
the outer context generic signature with an additional generic parameter representing the underlying
type and its exposed constraints. Opaque types also need to be keyed by their originating decl, so
that we can treat values of the same opaque type as the same. When we check a FuncDecl with an
opaque type specified as its return type, create an OpaqueTypeDecl and associate it with the
originating decl. (A representation for *types* derived from the opaque decl will come next.)
* Moves the IsStatic flag from VarDecl to AbstractStorageDecl.
* Adds a StaticSubscriptKind to SubscriptDecl.
* Updates serialization for these changes.
* Updates SubscriptDecl constructor call sites for these changes.
While checking for superclasses in isUnitTest, we need to handle
circular inheritance. For good measure, add tests for protocols as well.
The new API is designed to behave the same as walkInheritedProtocols
except that is walks over superclasses.
rdar://49434989
This is a step in the direction of fixing the fallthrough bug. Specifically, in
this commit I give case stmts a set of var decls for the bodies of the case
statement. I have not wired them up to anything except the var decl
list/typechecking.
rdar://47467128
* [typechecker] fix an issue with redeclaration checking
* [typechecker] use mapSignatureFunctionType in getOverloadSignatureType() to compute the type for the enum element decl, etc
* [typechecker] allow matching enums to functions as well, not just functions to enums
* [typechecker] fix the check for two enums
* [typechecker] check for nominal types as well when comparing enum elements
* [test] add more tests
* [typechecker] check for typealias as well
This is in preparation for fixing issues around SILGenPattern fallthrough
emission and bad rename/edit all in scope of case stmt var decls. Specifically,
I am going to ensure that we can get from any VarDecl in the following to any
other VarDecl:
switch x {
case .a(let v1, let v2), .b(let v1, let v2):
...
fallthrough
case .c(let v1, let v2), .d(let v1, let v2):
...
}
This will be done by:
1. Pointing the var decls in .d at the corresponding var decls in .c.
2. Pointing the var decls in .c at the corresponding var decls in .b.
3. Pointing the var decls in .b at the corresponding var decls in .a.
4. Pointing the var decls in .a at the case stmt. Recognizing that we are asking
for the next VarDecl, but have a case stmt, we check if we have a fallthrough
case stmt. If so, follow down the fallthrough case stmts until you find a
fallthrough case stmt that doesn't fallthrough itself and then return the
corresponding var decl in the last case label item in that var decl (in the
above .d).
In a subsequent commit I am going to add case body var decls. The only change as
a result of that is that I will insert them into the VarDecl double linked list
after the last case var decl of each case stmt.
I did not wire anything up to it.
This is in preparation for fixing issues around SILGenPattern fallthrough
emission and bad rename/edit all in scope of case stmt var decls. Specifically,
I am going to ensure that we can get from any VarDecl in the following to any
other VarDecl:
switch x {
case .a(let v1, let v2), .b(let v1, let v2):
...
fallthrough
case .c(let v1, let v2), .d(let v1, let v2):
...
}
This will be done by:
1. Pointing the var decls in .d at the corresponding var decls in .c.
2. Pointing the var decls in .c at the corresponding var decls in .b.
3. Pointing the var decls in .b at the corresponding var decls in .a.
4. Pointing the var decls in .a at the case stmt. Recognizing that we are asking
for the next VarDecl, but have a case stmt, we check if we have a fallthrough
case stmt (which I am going to add in a subsequent commit). If so, follow down
the fallthrough case stmts until you find a fallthrough case stmt that doesn't
fallthrough itself and then return the corresponding var decl in the last case
label item in that var decl (in the above .d).
I also put in some asserts to make sure that we never try to vend a parent value
that is a nullptr.
rdar://47467128
The observer in a dynamic replacement of variables with a observer will
provide the dynamic replacement for the original.
var original : Int = 0 {
didSet {
print("original")
}
}
@_dynamicReplacement(for: original)
var replacement : Int = 0 {
didSet {
print("replacement")
}
}
rdar://48518788
Introduce stored property default argument kind
Fix indent
Assign nil to optionals with no initializers
Don't emit generator for stored property default arg
Fix problem with rebase
Indentation
Serialize stored property default arg text
Fix some tests
Add missing constructor in test
Print stored property's initializer expression
cleanups
preserve switch
complete_constructor
formatting
fix conflict
If a value decl is internal hasTestableOrPrivateImport will succeed (or
fail) without looking at the filename. However this breaks when we query
an internal storage decl with private formal access for a private
setter: the query would fail because no filename was serialized for the
decl (we only serialize filenames for private decls). So in the special
case of a internal storage with private accessor also serialize the
filename.
rdar://48516545
Rather than eagerly doing a bunch of name lookups to establish the known
protocol kind, lazily match the ProtocolDecl to the list of known
protocols as-needed. This eliminates a bunch of up-front unqualified
name lookups when spinning up a type checker.
