As I've been iterating on this work, I've been gradually mulling these
over, and I think this is the way to go for now. These should make it
a lot less cumbersome to write these kinds of traversals correctly.
The intent is to the sunset the existing expanded-components stuff
after I do a similar pass for function parameters.
This allows the AP to answer questions like how many
elements/parameters in the substituted type correspond to
this pack expansion.
I've threaded this through a lot of cases for foreign patterns
that probably won't ever need it.
- SILPackType carries whether the elements are stored directly
in the pack, which we're not currently using in the lowering,
but it's probably something we'll want in the final ABI.
Having this also makes it clear that we're doing the right
thing with substitution and element lowering. I also toyed
with making this a scalar type, which made it necessary in
various places, although eventually I pulled back to the
design where we always use packs as addresses.
- Pack boundaries are a core ABI concept, so the lowering has
to wrap parameter pack expansions up as packs. There are huge
unimplemented holes here where the abstraction pattern will
need to tell us how many elements to gather into the pack,
but a naive approach is good enough to get things off the
ground.
- Pack conventions are related to the existing parameter and
result conventions, but they're different on enough grounds
that they deserve to be separated.
`getValue` -> `value`
`getValueOr` -> `value_or`
`hasValue` -> `has_value`
`map` -> `transform`
The old API will be deprecated in the rebranch.
To avoid merge conflicts, use the new API already in the main branch.
rdar://102362022
We had two notions of canonical types, one is the structural property
where it doesn't contain sugared types, the other one where it does
not contain reducible type parameters with respect to a generic
signature.
Rename the second one to a 'reduced type'.
Since I am beginning to prepare for adding real move only types to the language,
I am renaming everything that has to do with copyable types "move only wrapped"
values instead of move only. The hope is this reduces/prevents any confusion in
between the two.
Before the introduction of parameterized existential types, there
was no generic structure under these types. Now that there is, we'll
need to recurse into them to pick up any latent generic types
and lower them appropriately.
rdar://94320481
Just forgot to change these when I changed the name of the SILType methods. In
summary:
1. withoutMoveOnly -> removingMoveOnlyWrapper
2. withMoveOnly -> addingMoveOnlyWrapper
Represent this in much the same way that collections do by creating an opaque value representing the source argument, and a conversion expression representing the destination argument.
A PackExpansionType is the interface type of the explicit expansion of a
corresponding set of variadic generic parameters.
Pack expansions are spelled as single-element tuples with a single variadic
component in most contexts except functions where they are allowed to appear without parentheses to match normal variadic declaration syntax.
```
func expand<T...>(_ xs: T...) -> (T...)
~~~~ ~~~~~~
```
A pack expansion type comes equipped with a pattern type spelled before
the ellipses - `T` in the examples above. This pattern type is the subject
of the expansion of the pack that is tripped when its variadic generic
parameter is substituted for a `PackType`.
A pack type looks a lot like a tuple in the surface language, except there
is no way for the user to spell a pack. Pack types are created by the solver
when it encounters an apply of a variadic generic function, as in
```
func print<T...>(_ xs: T...) {}
// Creates a pack type <String, Int, String>
print("Macs say Hello in", 42, " different languages")
```
Pack types substituted into the variadic generic arguments of a
PackExpansionType "trip" the pack expansion and cause it to produce a
new pack type with the pack expansion pattern applied.
```
typealias Foo<T...> = (T?...)
Foo<Int, String, Int> // Forces expansion to (Int?, String?, Int?)
```
The GSB will drop same-type requirements sometimes, when the
right hand side is smaller than the left. Change the order
when adding these requirements, which seems to work well
enough for my reduced testcase.
Also, ensure that everything works correctly with the
RequirementMachine, which doesn't have the same underlying
problems with same-type requirement handling.
Fixes rdar://86431977.
This change separates out the formation of the generic signature and
substitutions for a SIL substituted function type as a pre-pass
before doing the actual function type lowering. The only input we
really need to form this signature is the original abstraction pattern
that a type is being lowered against, and pre-computing it should make
the code less side-effecty and confusing. It also allows us to handle
generic nominal types in a more robust way; we transfer over all of
the nominal type requirements to the generalized generic signature,
then when recursively visiting the bindings, we same-type-constrain
the generic parameters used in those requirements to the newly-generalized
generic arguments. This ensures that the minimized signature preserves
any non-trivial requirements imposed by the nominal type, such as
conditional conformances on its type arguments, same-type constraints
among associated types, etc.
This approach does lead to less-than-optimal generalized generic
signatures getting generated, since nominal type generic arguments
get same-type-bound either to other generic arguments or fixed to
concrete types almost always. It would be useful to do a minimization
pass on the final generic signature to eliminate these unnecessary
generic arguments, but that can be done in a follow-up PR.
Literal closures are only ever directly referenced in the context of the expression they're written in,
so it's wasteful to emit them at their fully-substituted calling convention and then reabstract them if
they're passed directly to a generic function. Avoid this by saving the abstraction pattern of the context
before emitting the closure, and then lowering its main entry point's calling convention at that
level of abstraction. Generalize some of the prolog/epilog code to handle converting arguments and returns
to the correct representation for a different abstraction level.
Literal closures are only ever directly referenced in the context of the expression they're written in,
so it's wasteful to emit them at their fully-substituted calling convention and then reabstract them if
they're passed directly to a generic function. Avoid this by saving the abstraction pattern of the context
before emitting the closure, and then lowering its main entry point's calling convention at that
level of abstraction. Generalize some of the prolog/epilog code to handle converting arguments and returns
to the correct representation for a different abstraction level.
Literal closures are only ever directly referenced in the context of the expression they're written in,
so it's wasteful to emit them at their fully-substituted calling convention and then reabstract them if
they're passed directly to a generic function. Avoid this by saving the abstraction pattern of the context
before emitting the closure, and then lowering its main entry point's calling convention at that
level of abstraction. Generalize some of the prolog/epilog code to handle converting arguments and returns
to the correct representation for a different abstraction level.
When converting an ObjC method type which is being called as async to a
Swift function type, some of the values passed to the ObjC method's
completion handler are converted to return values of the Swift function.
The flag and error parameters, however, if present, are ignored.
When abstracting the result type for the Swift method, the formal type
of the corresponding parameter in the ObjC method's completion handler
is used. Digging out that parameter entails indexing into the
parameters of the completion handler. Previously, the indexing logic
relied on the error appearing before the flag if both appeared before
the value of interest. Here, the indexing is tweaked to check both
special indices for each possible index until the first that matches
neither is found.
rdar://81625544
Address a FIXME where lowered types rather than formal types were used
when converting from objc to native types which resulted in a failure to
convert block types.
Remove the default argument for the `memberType`
parameter and enforce that GenericFunctionType is
not passed. Also add a defaulted overload for the
property case, as they should never have a
GenericFunctionType interface type.
Only the root archetype is a OpaqueTypeArchetypeType; the nested types are
NestedArchetypeType. Use the correct predicate here.
Also remove a dead check in tuple lowering; the isa<OpaqueTypeArchetypeType>()
check is dominated by isTypeParameterOrOpaqueArchetype() which is always
true if isa<OpaqueTypeArchetypeType>() is true anyway.
Fixes rdar://problem/79597666.
AbstractionPattern::matchesTuple() is used by various assertions, and
the condition was too strict. Relax the condition to fix an assertion
failure in the case where an opaque result type has a tuple as its
underlying type.
Fixes https://bugs.swift.org/browse/SR-14426 / rdar://problem/76057095.
This change adds support for calling `operator()` from Swift code.
As the C++ interop manifesto describes, `operator()` is imported into Swift as `callAsFunction`.
Import APIs with the `swift_async_error` attribute in `zero_argument` or `nonzero_argument`
modes by checking the corresponding boolean argument to indicate the error status, instead of
treating it as part of the result tuple. rdar://70594666
Plumb generic signatures through the codegen for invoking foreign APIs as async, so that we
correctly handle APIs declared on ObjC lightweight generic classes. rdar://74361267
An ObjC API maybe imported as async that had multiple non-error arguments to
its completion handler, which we treat in Swift as returning a tuple. Use a new
form of abstraction pattern to represent this return type, to maintain the
correct relation between individual tuple elements and the Clang block parameter
types they map to.
