This is obviously the right thing to do in terms of ensuring
that two different expressions of the same signature always result
in the same type. It also has the pleasant side-effect of causing
the canonical function type to never be expressed in terms of type
parameters which have been equated with concrete types, which means
that various consumers that work primarily with canonical types
(such as SILGen and IRGen) no longer have to worry about such types,
at least when decomposing a generic function signature.
There was a weirdness with ProtocolType::get() that was causing me grief
while trying to refactor getDeclaredType() and related code in another
patch.
Instead of caching the result like we do elsewhere, this would directly
store the new type into the ProtocolDecl. This is smelly, so let's not
do that.
I don't think this caused any problems until now, but it will
come up once the parent type can itself be a BoundGenericType,
because then we need to inherit recursive properties from the
generic arguments.
Being generic, the '_unwrapped' intrinsics force trafficking through memory, and while they're transparent so always get inlined, we don't do memory promotion in -Onone. Emitting the branch inline lets loadable optionals stay values leading to better -Onone codegen. (It also lets us throw away a surprising amount of support code for these optional intrinsics.)
We already have detailed knowledge of Optional's layout in SILGen, so these intrinsics were almost unused. They were only used in a few obscure places by some optional-to-bool conversions, used by 'is [A]' collection tests and the codegen for 'lazy' properties. Change these over to generate an EnumIsCaseExpr that we can directly lower to a 'select_enum' instruction in SILGen, leading to better codegen and obviating the need for these intrinsic functions.
This is a follow-up to the change that allowed one to omit @objc (or
the name in an @objc) when it can be inferred by matching a
requirement. There is no point in suggesting that one add @objc if it
will be inferred anyway, since it's just syntactic noise.
The verifier now asserts that Throws, ThrowsLoc and isBodyThrowing()
match up.
Also, add /*Label=*/ comments where necessary to make the long argument
lists easier to read, and cleaned up some inconsistent naming conventions.
I caught a case where ClangImporter where we were passing in a loc as
StaticLoc instead of FuncLoc, but probably this didn't affect anything.
When a non-@objc witness matches an @objc requirement except for
@objc-ness, treat it the same way whether it's an optional requirement
or not, except that it's a warning for the optional case. Should
finish off rdar://problem/25159872.
When an optional requirement of an @objc protocol has a selector that
collides with an entity that has a different *Swift* name but produces
an Objective-C method with the same selector, we have an existing
diagnostic complaining about the conflict. In such cases, make a few
suggestions (with Fix-Its) to improve the experience:
* Change Swift name to match the requirement, adding or modifying the
@objc as appropriate.
* Add "@nonobjc" to silence the diagnostic, explicitly opting out of
matching an @objc requirement.
This is intended to help with migration of Swift 2 code into Swift
3. The Swift 2 code will produce selectors that match Objective-C
methods in the protocol from Swift names that don't match; this helps
fix up those Swift names so that we now match.
Fixes the rest of rdar://problem/25159872. In some sense, it's a
stop-gap for more detailed checking of near-misses for optional
requirements, but it's not clear how wide-reaching such changes would
be.
When an optional requirement of an @objc protocol has a selector that
collides with an entity that has a different *Swift* name but produces
an Objective-C method with the same selector, we have an existing
diagnostic complaining about the conflict. In such cases, make a few
suggestions (with Fix-Its) to improve the experience:
* Change Swift name to match the requirement, adding or modifying the
@objc as appropriate.
* Add "@nonobjc" to silence the diagnostic, explicitly opting out of
matching an @objc requirement.
This is intended to help with migration of Swift 2 code into Swift
3. The Swift 2 code will produce selectors that match Objective-C
methods in the protocol from Swift names that don't match; this helps
fix up those Swift names so that we now match.
Fixes the rest of rdar://problem/25159872. In some sense, it's a
stop-gap for more detailed checking of near-misses for optional
requirements, but it's not clear how wide-reaching such changes would
be.
Implements SE-0055: https://github.com/apple/swift-evolution/blob/master/proposals/0055-optional-unsafe-pointers.md
- Add NULL as an extra inhabitant of Builtin.RawPointer (currently
hardcoded to 0 rather than being target-dependent).
- Import non-object pointers as Optional/IUO when nullable/null_unspecified
(like everything else).
- Change the type checker's *-to-pointer conversions to handle a layer of
optional.
- Use 'AutoreleasingUnsafeMutablePointer<NSError?>?' as the type of error
parameters exported to Objective-C.
- Drop NilLiteralConvertible conformance for all pointer types.
- Update the standard library and then all the tests.
I've decided to leave this commit only updating existing tests; any new
tests will come in the following commits. (That may mean some additional
implementation work to follow.)
The other major piece that's missing here is migration. I'm hoping we get
a lot of that with Swift 1.1's work for optional object references, but
I still need to investigate.
- Extract the cache entry type to a top-level type that can be used in the
signature of the function.
- Rewrite the implementation of the type in terms of standard LLVM ADTs
instead of manual bit manipulation.
- Add support for trivial-with-optional types (none of which exist yet).
- Drop the use of SIL/BridgedTypes.def; the only non-trivial non-object
bridged type today is 'Bool' (for ObjCBool and DarwinBoolean) and that's
already trivially bridged to CBool too.
- Save an Identifier lookup when possible.
- Finally, rename the function to getForeignRepresentationInfo.
No intended functionality change.
With the exception of a specific whitelist of cases where the
Foundation module defines conformances to _ObjectiveCBridgeable for
standard library types, only permit an _ObjectiveCBridgeable
conformance in the same module as the type that's conforming to the
protocol. Among other things, this prevents the optimizer from
concluding that a dynamic cast between a Swift value type and its
bridged Objective-C class type can never succeed. See
34ff1c8e6d
for the optimizer issue. As part of this, bring the whitelist in sync
with reality, now that the compiler enforces it.
Introduce abstraction patterns for curried C-functions-as-methods for type lowering, and plumb the "foreign self parameter index" through call emission so that we emit the "self" parameter in the right position. This gets us handling C functions imported as methods with explicit swift_name attributes in simple, fully-applied cases. There's still more work to be done for properties, partial applications, and initializers introduced by extensions.
Migrate the check for whether a given type is representable in
Objective-C, which is currently used to verify when @objc can be
inferred or verify that an explicitly-written @objc is well-formed,
from Sema into a set of queries on the Type within the AST library, so
it can be used in other parts of the compiler.
As part of this refactoring, clean up and improve a number of aspects
of this code:
* Unify the "trivially representable" and "representable" code paths
into a single code path that covers these cases. Clarify the
different levels of "representable" we have in both the code and
in comments.
* Distinguish between representation in C vs. representation in
Objective-C. While we aren't using this now, I'm anticipating it
being useful to allow exporting C interfaces via @_cdecl (or
similar).
* Eliminate the special cases for bridging String/Array/Dictionary/Set
with their Foundation counterparts; we now consult
_ObjectiveCBridgeable conformances exclusively to get this
information.
* Cache foreign-representation information on the ASTContext in a
manner that will let us more easily get the right answer across
different contexts while providing more sharing than the TypeChecker
version.
Annoyingly, this only seemed to fix a small class of error where we
were permitting Unsafe(Mutable)Pointer<T> to be representable in
Objective-C when T was representable but not trivially representable,
e.g., T=String or T=AnyObject.Type.
There's an immediate need for this in the core libs, and we have most of the necessary pieces on hand to make it easy to implement. This is an unpolished initial implementation, with the following limitations, among others:
- It doesn't support bridging error conventions,
- It relies on ObjC interop,
- It doesn't check for symbol name collisions,
- It has an underscored name with required symbol name `@cdecl("symbol_name")`, awaiting official bikeshed painting.
Fix some interface type/context type confusion in the AST synthesis from the previous patch, add a unique private mangling for behavior protocol conformances, and set up SILGen to emit the conformances when property declarations with behaviors are visited. Disable synthesis of the struct memberwise initializer if any instance properties use behaviors; codegen will need to be redesigned here.
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.
Similarly to how we've always handled parameter types, we
now recursively expand tuples in result types and separately
determine a result convention for each result.
The most important code-generation change here is that
indirect results are now returned separately from each
other and from any direct results. It is generally far
better, when receiving an indirect result, to receive it
as an independent result; the caller is much more likely
to be able to directly receive the result in the address
they want to initialize, rather than having to receive it
in temporary memory and then copy parts of it into the
target.
The most important conceptual change here that clients and
producers of SIL must be aware of is the new distinction
between a SILFunctionType's *parameters* and its *argument
list*. The former is just the formal parameters, derived
purely from the parameter types of the original function;
indirect results are no longer in this list. The latter
includes the indirect result arguments; as always, all
the indirect results strictly precede the parameters.
Apply instructions and entry block arguments follow the
argument list, not the parameter list.
A relatively minor change is that there can now be multiple
direct results, each with its own result convention.
This is a minor change because I've chosen to leave
return instructions as taking a single operand and
apply instructions as producing a single result; when
the type describes multiple results, they are implicitly
bound up in a tuple. It might make sense to split these
up and allow e.g. return instructions to take a list
of operands; however, it's not clear what to do on the
caller side, and this would be a major change that can
be separated out from this already over-large patch.
Unsurprisingly, the most invasive changes here are in
SILGen; this requires substantial reworking of both call
emission and reabstraction. It also proved important
to switch several SILGen operations over to work with
RValue instead of ManagedValue, since otherwise they
would be forced to spuriously "implode" buffers.
There's a group of methods in `DeclContext` with names that start with *is*,
such as `isClassOrClassExtensionContext()`. These names suggests a boolean
return value, while the methods actually return a type declaration. This
patch replaces the *is* prefix with *getAs* to better reflect their interface.
