A live range representing the ownership of addressible memory.
This live range represents the minimal guaranteed lifetime of the object being addressed. Uses of derived addresses
may be extended up to the ends of this scope without violating ownership.
.liveOut objects (@in_guaranteed, @out and globals) have no instruction range.
.local objects (alloc_stack, yield, @in, @inout) report the single live range of the full assignment that reaches
this address.
.owned values (boxes and references) simply report OSSA liveness.
.borrow values report each borrow scope's range. The effective live range is their intersection. A valid use must
lie within
Compute the live range for the borrow scopes of a guaranteed value. This returns a separate instruction range for
each of the value's borrow introducers. Unioning those ranges would be incorrect. We typically want their
intersection.
Only rewrite the mark_dependence to depend on the function argument when the
dependent value is actually returned.
Also, find all uses even if an escaping use is seen.
This avoids a lot of confusion because the callers expect this type. Fixing it just required some redundancy and
bridging in the EnclosigValues implementation.
For years, optimizer engineers have been hitting a common bug caused by passes
assuming all SILValues have a parent function only to be surprised by SILUndef.
Generally we see SILUndef not that often so we see this come up later in
testing. This patch eliminates that problem by making SILUndef uniqued at the
function level instead of the module level. This ensures that it makes sense for
SILUndef to have a parent function, eliminating this possibility since we can
define an API to get its parent function.
rdar://123484595
These were always redundant. And there is no way to emit them
correctly for valid OSA when the original dependence scope is in the
caller.
NFC without:
-enable-experimental-feature NonescapableTypes
-enable-lifetime-dependence-diagnostics
Improve noescape function handling. Use the mayEscape API.
Improve handling of @_unsafeNonescapableResult.
Improve handling of initialized scopes. Use findSingleInitializer.
Provide APIs needed by lifetime dependence diagnostics, namely LifetimeDependenceConvention.
Reorganize the APIs so it's easy to find related functionality which
API is responsible for which functionality.
Remove the originalFunctionConvention complexity. It is no longer
needed for lifetime dependence inference, and generally should be
avoided in SIL.
Add some placeholder FIXMEs because this not a good PR in which to
change existing functionality.
