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.
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
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.
This unusual situation can happen if an address is converted to a raw pointer and that pointer is stored to a memory location.
In this case the walkers need to follow load instructions even if the visitor and current projection path don't say so.
Fixes a miscompile
rdar://122805546
We need to keep the original linkage because it would be illegal to call a shared not-serialized function from a serialized function.
Also, rename the API to create the specialized function.
Generic specialization already takes care of removing metatype arguments of generic functions.
But sometimes non-generic functions have metatype arguments which must be removed.
We need handle this case with a function signature optimization.
This enables, for example, to use `OptionSet` in embedded swift.
rdar://121206953
