It is necessary for opaque values where for casts that will newly start
out as checked_cast_brs and be lowered to checked_cast_addr_brs, since
the latter has the source formal type, IRGen relies on being able to
access it, and there's no way in general to obtain the source formal
type from the source lowered type.
"reborrow" flag on the SILArgument avoids transitive walk over the phi operandsi
to determine if it is a reborrow in multiple utilities.
SIL transforms must keep the flag up-to-date by calling SILArgument::setReborrow.
SILVerifier checks to ensure the flag is not invalidated.
Currently "escaping" is not used anywhere.
Although nonescaping closures are representationally trivial pointers to their
on-stack context, it is useful to model them as borrowing their captures, which
allows for checking correct use of move-only values across the closure, and
lets us model the lifetime dependence between a closure and its captures without
an ad-hoc web of `mark_dependence` instructions.
During ownership elimination, We eliminate copy/destroy_value instructions and
end the partial_apply's lifetime with an explicit dealloc_stack as before,
for compatibility with existing IRGen and non-OSSA aware passes.
Add ScopedAddressOperand and ScopedAddressValue abstraction utilities
Introduce verification for store_borrow to validate its uses are correctly enclosed in their scope.
Include end_borrow/end_access as implicit uses while validating a borrow introducer
Add flow sensitive verifier rule for store_borrow/end_borrow pair
Make sure store_borrow is always to an alloc_stack
Make sure uses to store borrow location are via its return address only
This change ensures all store_borrows are ended with an end_borrow, and uses of the store_borrow
destination are all in the enclosing store_borrow scope and via the store_borrow return address.
Fix tests to reflect new store_borrow pattern
The old syntax was
@opened("UUID") constraintType
Where constraintType was the right hand side of a conformance requirement.
This would always create an archetype where the interface type was `Self`,
so it couldn't cope with member types of opened existential types.
Member types of opened existential types is now a thing with SE-0309, so
this lack of support prevented writing SIL test cases using this feature.
The new syntax is
@opened("UUID", constraintType) interfaceType
The interfaceType is a type parameter rooted in an implicit `Self`
generic parameter, which is understood to be the underlying type of the
existential.
Fixes rdar://problem/93771238.
