In Embedded Swift, witness method lookup is done from specialized witness tables.
For this to work, the type of witness_method must be specialized as well.
Otherwise the method call would be done with wrong parameter conventions (indirect instead of direct).
In Embedded Swift, witness method lookup is done from specialized witness tables.
For this to work, the type of witness_method must be specialized as well.
Otherwise the method call would be done with wrong parameter conventions (indirect instead of direct).
For now this will only be used for HopToMainActorIfNeeded thunks. I am creating
this now since in the past there has only been one option for creating
thunks... to create the thunk in SILGen using SILGenThunk. This code is hard to
test and there is a lot of it. By using an instruction here we get a few benefits:
1. We decouple SILGen from needing to generate new kinds of thunks. This means
that SILGenThunk does not need to expand to handle more thunks.
2. All thunks implemented via ThunkInst will be easy to test in a decoupled way
with SIL tests.
3. Even though this stabilizes the patient, we still have many thunks in SILGen
and various parts of the compiler. Over time, we can swap to this model,
allowing us to hopefully eventually delete SILGenThunk.
MandatoryPerformanceOptimizations already did most of the vtable specialization work.
So it makes sense to remove the VTableSpecializerPass completely and do everything in MandatoryPerformanceOptimizations.
The reason why is that we want to distinguish inbetween SILFunction's that are
marked as unspecified by SILGen and those that are parsed from textual SIL that
do not have any specified isolation. This will make it easier to write nice
FileCheck tests against SILGen output on what is the inferred isolation for
various items.
NFCI.
The generality of the `AvailabilityContext` name made it seem like it
encapsulates more than it does. Really it just augments `VersionRange` with
additional set algebra operations that are useful for availability
computations. The `AvailabilityContext` name should be reserved for something
pulls together more than just a single version.
Some requirement machine work
Rename requirement to Value
Rename more things to Value
Fix integer checking for requirement
some docs and parser changes
Minor fixes
Also, move this rule from the computation of lowered captures in SIL,
to the computation of AST captures in Sema. This allows us to
correctly handle the case where an async function nests inside a
sync function. It also removes a special case that was added recently
to cope with a generic `self` type.
Fixes rdar://129366819.
If there is no read from an indirect argument, this argument has to be dropped.
At the call site the store to the argument's memory location could have been removed (based on the callee's memory effects).
Therefore, converting such an unused indirect argument to a direct argument, would load an uninitialized value at the call site.
This would lead to verifier errors and in worst case to a miscompile because IRGen can implicitly use dead arguments, e.g. for getting the type of a class reference.
Instead of adding a "flag" (`m` in `...Tgm5`) make it more generic to allow to drop any unused argument.
Add all dropped arguments with a `t<n-1>` (where `<n-1>` is empty for n === 0). For example `...Ttt2g5`.
Do this even if the function then contains references to other functions with wrong linkage. Instead fix the linkage later.
Fixes a false error in embedded swift.
rdar://134352676
