When checking for false positives, we want to make sure that if a
debug_value is dropped, we also find a real instruction that shares
the same scope as the debug_value or has a scope that is a child
of the scope of the debug_value, and has an inlinedAt equal to the
inlinedAt of the debug_value or it's inlinedAt chain contains the
inlinedAt of the debug_value. However, this instruction shouldn't be
another debug_value.
The check was supossed to check if(!I.isDebugInstruction())
but it checked if(I.isDebugInstruction())
This patch fixes that bug.
Regardless of consumes of copies, if the original lexical value is not
consumed on a dead-end path, it must remain live to that dead-end.
rdar://145226757
At one point, OpenedArchetypeType did not exist as a separate subclass
of ArchetypeType, so this method did something. Now, it's just
equivalent to calling is<> or isa<>.
I also removed a couple of asserts that were obvious no-ops as a result.
To handle borrowing operands that produce a dependence value but do not create a
nested borrow scope. This includes non-reborrow borrowed-from and guaranteed
mark_dependence [nonescaping].
This also fixes a case where we would have inferred the wrong isolation (which
the assert caught). I think we missed this since it only comes up with final
classes.
rdar://142568522
CSE uses OSSA rauw which creates copies and copies that are created to optimize
across borrow scopes are unoptimizable. This PR avoids this situation for now.
Introduce a new experimental feature StrictSendableMetatypes that stops
treating all metatypes as `Sendable`. Instead, metatypes of generic
parameters and existentials are only considered Sendable if their
corresponding instance types are guaranteed to be Sendable.
Start with enforcing this property within region isolation. Track
metatype creation instructions and put them in the task's isolation
domain, so that transferring them into another isolation domain
produces a diagnostic. As an example:
func f<T: P>(_: T.Type) {
let x: P.Type = T.self
Task.detached {
x.someStaticMethod() // oops, T.Type is not Sendable
}
}
executing unknown code
This means we have to claw back some performance by recognizing harmless
releases.
Such as releases on types we known don't call a deinit with unknown
side-effects.
rdar://143497196
rdar://143141695
It's sufficient just to have a struct with a kind and a value. There
aren't any cases where the payload's original type benefits from being
statically preserved--they're only ever obtained as `SILValue`s. Keep
the type safety by way of constructors.
This is necessary to fix a recent OSSA bug that breaks common occurrences on
mark_dependence [nonescaping]. Rather than reverting that change above, we make
forward progress toward implicit borrows scopes, as was the original intention.
In the near future, all InteriorPointer instructions will create an implicit
borrow scope. This means we have the option of not emitting extraneous
begin/end_borrow instructions around intructions like ref_element_addr,
open_existential, and project_box. After that, we can also migrate
GuaranteedForwarding instructions like tuple_extract and struct_extract.
To find if all the uses are within a guaranteed value, we should find all borrow introducers.
swift::findOwnershipReferenceAggregate looks only through forwarding operations with single operands.
For simplicity, continue using swift::findOwnershipReferenceAggregate, but return false when it does
not find a borrow introducer.
Handle the special case of an guaranteed return value with no uses.
Fixes an assertion crash.
Unfortunately I don't have an isolated test case for this.
But this problem showed up in the `Interpreter/moveonly_read_modify_coroutines.swift` test with OSSA modules and will therefore be tested by this test once we enable OSSA modules.
The problem with `is_escaping_closure` was that it didn't consume its operand and therefore reference count checks were unreliable.
For example, copy-propagation could break it.
As this instruction was always used together with an immediately following `destroy_value` of the closure, it makes sense to combine both into a `destroy_not_escaped_closure`.
It
1. checks the reference count and returns true if it is 1
2. consumes and destroys the operand
This is used for synthetic uses like _ = x that do not act as a true use but
instead only suppress unused variable warnings. This patch just adds the
instruction.
Eventually, we can use it to move the unused variable warning from Sema to SIL
slimmming the type checker down a little bit... but for now I am using it so
that other diagnostic passes can have a SIL instruction (with SIL location) so
that we can emit diagnostics on code like _ = x. Today we just do not emit
anything at all for that case so a diagnostic SIL pass would not see any
instruction that it could emit a diagnostic upon. In the next patch of this
series, I am going to add SILGen support to do that.
To determine where a lifetime ends within dead-end blocks,
OSSACanonicalizeOwned uses OSSACompleteLifetime's
visitAvailabilityBoundary. This API takes a liveness which it uses to
walk forward to the availability boundary. Specifically, the liveness
passed from OSSACanonicalizeOwned to OSSACompleteLifetime is a variation
of OSSACanonicalizeOwned's own liveness (it has destroys added).
There is a mismatch in the characteristics of livenesses created by
OSSACanonicalizeOwned and OSSACompleteLifetime: The former deals with
not only direct uses of a value but also uses of its copies; that
introduces the possibility for consuming uses in the middle of liveness.
The latter on the other hand deals only with uses of a single value
(nestedly, but at each level of nesting only a single value). Passing a
liveness from the former to the latter without handling this mismatch
is incorrect: OSSACompleteLifetime understands consuming uses to always
end a lifetime, even when they are in the middle of a copy-extended
liveness. The result is that OSSACompleteLifetime produces non-sensical
results when provided with such a liveness.
To address this, fixup the liveness passed from OSSACanonicalizeOwned to
OSSACompleteLifetime by demoting consuming uses that appear within
(that's to say _not_ on the boundary) of liveness to non-consuming uses.
rdar://142846936
When visiting a consuming use of a move-only value (which can be
produced by a forwarding operation), the inner rewriter must bail out.
Otherwise, it would produce a copy of that move-only value.
rdar://142520491
