There were several bits of code which were unnecessarily
repeating the core logic of breaking down an access strategy
and either setting up an LValue or directly emitting it.
These places have now been unified to just create and then
load or othrwise use an LValue.
Introduce a visitor which handles the common parts of breaking
down an access strategy and computing information like the
LValueTypeData. In addition to its direct benefits (which are
somewhat lost in the boilerplate of capturing local state into
the visitor subclass), this eliminates some of the ad-hocness
of how the various emission paths use AccessStrategy.
Finally, implement the MaterializeToTemporary strategy in its
full generality by using the actual read and write sub-strategies
instead of always falling back on calling the getter and setter.
This part is not NFC because it causes us to perform the read
part of a read/write to a stored-with-observers property by
directly accessing the storage instead of calling the getter.
Modifies SILGen and the `Swift._diagnoseUnexpectedNilOptional` call to print a slightly different message for force unwraps which were implicitly inserted by the compiler for IUOs. The message is chosen based on the presence of certain flags in the `ForceValueExpr`, not on the type of the value being unwrapped.
The other side of #17404. Since we don't want to generate up front key path metadata for properties/subscripts with no withheld implementation details, the client should generate a key path component that can be used to represent a key path component based on its public interface.
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.
Client code can make a best effort at emitting a key path referencing a property with its publicly exposed API, which in the common case will match what the defining module would produce as the canonical key path component representation of the declaration. We can reduce the code size impact of these descriptors by not emitting them when there's no hidden or possibly-resiliently-changed-in-the-past information about a storage declaration, having the property descriptor symbol reference a sentinel value telling client key paths to use their definition of the key path component.
This causes default arguments to get emitted after formal evaluation of `self`, allowing protocol methods to access the opened `Self` type of an existential receiver. Fixes rdar://problem/39524104
This reverts commit 742e7fc583. This
causes other source compatibility regressions due to the extended exclusive access to
the existential (such as rdar://problem/39524104). A false-positive
exclusivity failure might lead to runtime errors, whereas the cases we
can't support previous to this patch can at least reliably be handled
statically.
Every SubstitutionMap::toList() invocation would ASTContext-allocate
arrays for all of the conformances, then return a SmallVector of the
underlying substitutions, which both wastes memory *and* puts the onus
on the caller to allocate a copy of that outer SmallVector into the
ASTContext if it's going to be stored anywhere.
Stop the madness by caching an ASTContext-allocated SubstitutionList
within the storage for the SubstitutionMap. This both reduces repeated
allocations and eliminates the potential for errors.
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.
Replace manual substitution mapping by using the existing ProtocolConformanceRef::getAssociatedConformance helper to look up the Equatable conformance from Hashable. Replace use of manual Substitution construction with SubstitutionMaps.
- Fix some type system issues with looking up member types in/out of context.
- Correctly upcast a class-constrained existential or archetype to the base class when referencing a base class field on a generic type.
Fixes SR-7106 | rdar://problem/38070998.
A public subscript might have generic indexes that aren't unconditionally Hashable, or might use indexes that are retroactively made Hashable, so the property descriptor on the implementer's side can't always resiliently provide this information to the final instantiated KeyPath.
Along the .none path, select_enum+cond_br causes the ownership verifier to
trigger since the .none path looks like a leak. By using a switch_enum, we avoid
this problem since the ownership verifier thinks the switch_enum consumes the
input value and views the owned value along the .some path as a value with
separate ownership.
rdar://34222540
