Introduce a new request kind to capture the computation of the set of
overridden declarations of a given declaration, eliminating the
stateful “setOverriddenDecls()” calls from the type checker.
Several kinds of declarations can override other declarations, but the
computation and storage for these “overridden” declarations was scattered in
at least 3 different places, with different resolution paths. Pull them
all together into two bits of LazySemanticInfo in ValueDecl (“have we computed
overrides?” and “are there any overrides?”), with a side table for the
actual list of overrides.
One side effect here is that the AST can now represent multiple overridden
declarations, although only associated type declarations track this
information.
Start using LazyResolver::resolveOverriddenDecl() more consistently, unifying
it with the separate path we had for associated type overrides. All of this
is staging for a move to the request-evaluator for overridden declaration
computation.
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.
We sometimes serialized the “isObjC” state, and sometimes not. When we did serialize it,
we rarely used the bit for anything. Serialize it for all declarations where it makes
sense, and consistently call setIsObjC() with the deserialized value.
Now that @inlinable is a supported feature, we need to handle cases
where a function is inlinable but it references some type that imports
differently in different Swift versions. To start, handle the case
where a SIL function's type is now invalid and therefore the entire
function can't be imported. This doesn't open up anything interesting
yet, but it's a start.
Part of rdar://problem/40899824
The meaning of this bit changed way back in 3639343c53, but I forgot
to update this fast path. Thanks to this code falling back to the slow
path if things didn't work out, there wasn't a correctness issue here,
but it might have been doing more work than necessary.
Cross-references are identified by their containing module, with the
assumption that two modules will never have the same name. However, an
overlay has the same name as its underlying Clang module, which means
that there can be two declarations with the same name, the same type,
and the same module name. This is the underlying cause of the
'UIEdgeInsetsZero' problem, but it also affects the CloudKit overlay.
By tracking a bit that just says "this came from Clang", we're able
to resolve otherwise ambiguous cross-references.
(Why didn't we do it this way all along? Because if a declaration
moves from Clang to Swift or vice versa, that would break the
cross-reference. But that's only interesting if the swiftmodule format
is meant to be persistent across changing dependencies, and it looks
like we're moving away from that anyway. It's also a little weird for
SerializedModuleLoader to have special cases for Clang, but this isn't
the first.)
Note that I'm not reverting the UIEdgeInsetsZero workaround here; the
end state will have that coming just from UIKit as originally
described.
rdar://problem/40839486
This allows us to filter them out in cases that would otherwise be
ambiguous. The particular prompting situation looks a lot like the
test case: a protocol, plus a forward-declared class with the same
name. (Normally we ignore forward-declared classes, but SourceKit's
module interface generation feature makes dummy ClassDecls for them
instead.)
https://bugs.swift.org/browse/SR-4851
Introduce some metaprogramming of accessors and generally prepare
for storing less-structured accessor lists.
NFC except for a change to the serialization format.
LLVM r334399 (and related Clang changes) moved clang::VersionTuple to
llvm::VersionTuple. Update Swift to match.
Patch by Jason Molenda.
rdar://problem/41025046
Trade a tiny bit of speed in the happy path for a more sensible
result, and make sure to preserve the information about what was being
looked up when a cross-reference turns out to be ambiguous. No
intended functionality change.
Now that we use the C names of imported types in mangled names, it's
safe to resolve a compatibility alias when a type gets an
NS_SWIFT_NAME for the first time, rather than requiring the developer
to recompile the imported library.
This doesn't include generic types, which only applies for Objective-C
generics. There shouldn't be additional complications here but I want
to be extra careful.
rdar://problem/39661212
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).
Convert NameAliasType’s internal representation from tail-allocating an
array of Substitutions (to be treated as a SubstitutionList) to store a
single SubstitutionMap. Serialize using that SubstitutionMap.
Allow substitution maps to be serialized directly (via an ID), writing out
the replacement types and conformances as appropriate. This is a more
efficient form of serialization than the current SubstitutionList approach,
because it maintains uniqueness of substitution maps within a module file,
and is a step toward eliminating SubstitutionList entirely.
Avoid storing more information than necessary in witnesses
and establishing the invariant that we only use out-of-line
storage when we require substitutions.
Absence of synthetic generic environment should not affect
serialization of the required substitutions because they can
come from outer requirement context for static members.
Resolves: rdar://problem/36497404
We should always go through the Clang importer to reinstantiate them. Serializing them leads to the possibility of us ending up with multiple conformances with different identities that ought to be equivalent.
We should always go through the Clang importer to reinstantiate them. Serializing them leads to the possibility of us ending up with multiple conformances with different identities that ought to be equivalent.
