Calling `emitBeginBorrowOperation` on something which is `load_borrow`
for example with guaranteed ownership doesn't produce `begin_borrow`
instruction, so we need to be careful not to emit mismatched `end_borrow`
in such cases.
Implement "init accessor" component emission which is paired with
"init accessor" write strategy. Use `SILUndef` for a "setter" operand
of an "assign_or_init" instruction in cases when property with init
accessor doesn't have a setter. DI would detect re-initialization
attempts to produce diagnostics.
Instead of dealing with substitutions during raw SIL lowering,
let's produce a partial apply without argument to produce a
substituted reference that could be used by SILVerifier and
raw SIL lowering stages.
DI marks all of of the previously initialized properties and Raw SIL
lowering emits `destroy_addr` before calling init accessor for such
properties to destroy previously set value.
- Adds a missing check to `collectClassSelfUses` to find assign_or_init instructions;
- RawSIL lowering should start emitting access around synthesized member references.
This instruction is similar to AssignByWrapperInst, but instead of having
a destination operand, the initialization is fully factored into the init
function operand. Like AssignByWrapper, AssignOrInit has partial application
operands of both the initializer and the setter, and DI will lower the
instruction to a call based on whether the assignment is initialization or
a setter call.
- 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.
Type wrapper originated assignment instructions are lowered similar
to property wrapper ones except they don't require initializer call
because assignments are done to tuple fields.
If only the init-closure is used and the setter-closure is dead, the argument to the setter partial_apply also needs to be delete - in case it's a load.
Otherwise it would cause a memory lifetime failure.
* Refactoring: replace "Destination" and the ownership qualifier by a single "Mode". This represents much better the mode how the instruction is to be lowered. NFC
* Make assign_by_wrapper printable and parseable.
* Fix lowering of the assign modes for indirect results of the init-closure: The indirect result was initialized and not assigned to. The fix is to insert a destroy_addr before calling the init closure. This fixes a memory lifetime error and/or a memory leak. Found by inspection.
* Fix an iterator-invalidation crash in RawSILInstLowering
* Add tests for lowering assign_by_wrapper.
So far we left this cleanup to SILCombine.
But the unused partial_apply (i.e. the "set" in case it's an init or the "init" in case it's a set) violates memory lifetime rules in case "self" is an inout.
Once we verify that, it would result in a memory lifetime violation.
In case of a tuple as value type, the initializer and setter takes the tuple elements as separate arguments. This was just not handled in the assign_by_wrapper instruction lowering.
rdar://problem/53866473
I am doing this so I can start writing DI tests without this lowering occuring.
There never was a real reason for this code to be in DI beyond convenience. Now
it just makes writing tests more difficult. To prevent any test delta, I changed
all current DI tests to run this pass after DI.
