This allows the conversion of the Windows `BOOL` type to be converted to
`Bool` implicitly. The implicit bridging allows for a more ergonomic
use of the native Windows APIs in Swift.
Due to the ambiguity between the Objective C `BOOL` and the Windows
`BOOL`, we must manually map the `BOOL` type to the appropriate type.
This required lifting the mapping entry for `ObjCBool` from the mapped
types XMACRO definition into the inline definition in the importer.
Take the opportunity to simplify the mapping code.
Adjust the standard library usage of the `BOOL` type which is now
eclipsed by the new `WindowsBool` type, preferring to use `Bool`
whenever possible.
Thanks to Jordan Rose for the suggestion to do this and a couple of
hints along the way.
This was partially implemented but the check looked at the lowered
types and not the AST types, and DynamicSelfType is erased at the
top level of a lowered type.
Also use the new mangling for reabstraction thunks with self, to
ensure we don't emit the same symbol with two different lowered
types.
Fixes <https://bugs.swift.org/browse/SR-10309>, <rdar://problem/49703441>.
OpaqueValueState used to store a SILValue, so back then the IsConsumable flag
was meaningful. But now we can just check if the ManagedValue has a cleanup
or not.
Also, we were passing around an opened ArchetypeType for no good reason.
The ownership kind is Any for trivial types, or Owned otherwise, but
whether a type is trivial or not will soon depend on the resilience
expansion.
This means that a SILModule now uniques two SILUndefs per type instead
of one, and serialization uses two distinct sentinel IDs for this
purpose as well.
For now, the resilience expansion is not actually used here, so this
change is NFC, other than changing the module format.
If the block is guaranteed, we need to be sure to copy here. This can happen for
instance with arguments (where this was caught). I added a SILGen test that
exposes this failure since this is not an actual bug in PrintAsObjC.
This undoes some of Joe's work in 8665342 to add a guarantee: if an
@objc convenience initializer only calls other @objc initializers that
eventually call a designated initializer, it won't result in an extra
allocation. While Objective-C /allows/ returning a different object
from an initializer than the allocation you were given, doing so
doesn't play well with some very hairy implementation details of
compiled nib files (or NSCoding archives with cyclic references in
general).
This guarantee only applies to
(1) calling `self.init`
(2) where the delegated-to initializer is @objc
because convenience initializers must do dynamic dispatch when they
delegate, and Swift only stores allocating entry points for
initializers in a class's vtable. To dynamically find an initializing
entry point, ObjC dispatch must be used instead.
(It's worth noting that this patch does NOT check that the calling
initializer is a convenience initializer when deciding whether to use
ObjC dispatch for `self.init`. If we ever add peer delegation to
designated initializers, which is totally a valid feature, that should
use static dispatch and therefore should not go through objc_msgSend.)
This change doesn't /always/ result in fewer allocations; if the
delegated-to initializer ends up returning a different object after
all, the original allocation was wasted. Objective-C has the same
problem (one of the reasons why factory methods exist for things like
NSNumber and NSArray).
We do still get most of the benefits of Joe's original change. In
particular, vtables only ever contain allocating initializer entry
points, never the initializing ones, and never /both/ (which was a
thing that could happen with 'required' before).
rdar://problem/46823518
When the Clang importer imports the components of a C function pointer
type, it generally translates foreign types into their native equivalents,
just for the convenience of Swift code working with those functions.
However, this translation must be unambiguously reversible, so (among
other things) it cannot do this when the native type is also a valid
foreign type. Specifically, this means that the Clang importer cannot
import ObjCBool as Swift.Bool in these positions because Swift.Bool
corresponds directly to the C type _Bool.
SIL type lowering manually reverses the type-import process using
a combination of duplicated logic and an abstraction pattern which
includes information about the original Clang type that was imported.
This abstraction pattern is generally able to tell SIL type lowering
exactly what type to reverse to. However, @convention(c) function
types may appear in positions from which it is impossible to recover
the original Clang function type; therefore the reversal must be
faithful to the proper rules. To do this we must propagate
bridgeability just as the imported would.
This reversal system is absolutely crazy, and we should really just
- record an unbridged function type for imported declarations and
- record an unbridged function type and Clang function type for
@convention (c) function types whenever we create them.
But for now, it's what we've got.
rdar://43656704
Dynamic replacements are currently written in extensions as
extension ExtendedType {
@_dynamicReplacement(for: replacedFun())
func replacement() { }
}
The runtime implementation allows an implementation in the future where
dynamic replacements are gather in a scope and can be dynamically
enabled and disabled.
For example:
dynamic_extension_scope CollectionOfReplacements {
extension ExtentedType {
func replacedFun() {}
}
extension ExtentedType2 {
func replacedFun() {}
}
}
CollectionOfReplacements.enable()
CollectionOfReplacements.disable()
To make that work, enter appropriate scopes (ArgumentScopes and
FormalEvaluationScopes) at a bunch of places. But note that l-value
emission generally can't enter such a scope, so in generic routines
like emitOpenExistentialExpr we have to just assert that we're
already in a scope.
This comes up when we import a static factory method as a convenience init.
The thunk was using DynamicSelfType as the type of a basic block argument,
because that was the type of the 'self' parameter in -swift-version 5.
Fixes <rdar://problem/44242156>.
This is NFC for now, but I plan to build on this to (1) immediately
remove some unnecessary materialization and loads of the base value
and (2) to allow clients to load a borrowed value.
I made this change by removing the SILOption and then doing a compile, fix loop. I
purposely did not move around the code to make the refactoring really easy to
see.
Separate out the semantic state for the ‘dynamic’ check (from the
presence of the attribute), and move all of the computation of the
‘dynamic’ bit into the request-evaluator.
In the process, this fixes a bug where implicitly-synthesized initializers
in subclasses of imported classes would not be implicitly made ‘final’.
More groundwork for protocols with superclass constraints.
In several places we need to distinguish between existential
types that have a superclass term (MyClass & Proto) and
existential types containing a protocol with a superclass
constraint.
This is similar to how I can write 'AnyObject & Proto', or
write 'Proto1 & Proto2' where Proto1 has an ': AnyObject'
in its inheritance clause.
Note that some of the usages will be revisited later as
I do more refactoring and testing. This is just a first pass.
The storage kind has been replaced with three separate "impl kinds",
one for each of the basic access kinds (read, write, and read/write).
This makes it far easier to mix-and-match implementations of different
accessors, as well as subtleties like implementing both a setter
and an independent read/write operation.
AccessStrategy has become a bit more explicit about how exactly the
access should be implemented. For example, the accessor-based kinds
now carry the exact accessor intended to be used. Also, I've shifted
responsibilities slightly between AccessStrategy and AccessSemantics
so that AccessSemantics::Ordinary can be used except in the sorts of
semantic-bypasses that accessor synthesis wants. This requires
knowing the correct DC of the access when computing the access strategy;
the upshot is that SILGenFunction now needs a DC.
Accessor synthesis has been reworked so that only the declarations are
built immediately; body synthesis can be safely delayed out of the main
decl-checking path. This caused a large number of ramifications,
especially for lazy properties, and greatly inflated the size of this
patch. That is... really regrettable. The impetus for changing this
was necessity: I needed to rework accessor synthesis to end its reliance
on distinctions like Stored vs. StoredWithTrivialAccessors, and those
fixes were exposing serious re-entrancy problems, and fixing that... well.
Breaking the fixes apart at this point would be a serious endeavor.
It is safe to omit the retain/release dance in the reabstraction thunk
because we know we have an aditional reference outstanding for the
is_escaping verification.
The problem with throwing an objc exception inside a noescape closure is
that we verify the reference count of the closure sentinel. The
reabstraction thunk would increase the reference count call the
implementation function that then throws skipping the decrement.
rdar://40857699
Replace two prominent uses of SubstitutionList, in ConcreteDeclRef and
Witness, with SubstitutionMap. Deal with the myriad places where we
now have substitution maps and need substitution lists (or vice versa)
caused by this change.
Overall, removes ~50 explicit uses of SubstitutionList (of ~400).
closure lifetimes.
SILGen will now unconditionally emit
%cvt = convert_escape_to_noescape [guaranteed] %op
instructions. The mandatory ClosureLifetimeFixup pass ensures that %op's
lifetime spans %cvt's uses.
The code in DefiniteInitialization that handled a subset of cases is
removed.
