The main point of this change is to make sure that a shared function always has a body: both, in the optimizer pipeline and in the swiftmodule file.
This is important because the compiler always needs to emit code for a shared function. Shared functions cannot be referenced from outside the module.
In several corner cases we missed to maintain this invariant which resulted in unresolved-symbol linker errors.
As side-effect of this change we can drop the shared_external SIL linkage and the IsSerializable flag, which simplifies the serialization and linkage concept.
I noticed that I enabled ownership verification on all of the simple run swift
tests, but I didn't on the simple build swift tests. I have prepared a commit
that enables that. This commit contains some test fixes needed to make it pass.
In a previous commit, I banned in the verifier any SILValue from producing
ValueOwnershipKind::Any in preparation for this.
This change arises out of discussions in between John, Andy, and I around
ValueOwnershipKind::Trivial. The specific realization was that this ownership
kind was an unnecessary conflation of the a type system idea (triviality) with
an ownership idea (@any, an ownership kind that is compatible with any other
ownership kind at value merge points and can only create). This caused the
ownership model to have to contort to handle the non-payloaded or trivial cases
of non-trivial enums. This is unnecessary if we just eliminate the any case and
in the verifier separately verify that trivial => @any (notice that we do not
verify that @any => trivial).
NOTE: This is technically an NFC intended change since I am just replacing
Trivial with Any. That is why if you look at the tests you will see that I
actually did not need to update anything except removing some @trivial ownership
since @any ownership is represented without writing @any in the parsed sil.
rdar://46294760
This is how we originally controlled whether or not we printed out ownership
annotations when we printed SIL. Since then, I have changed (a few months ago I
believe) the ownership model eliminator to know how to eliminate these
annotations from the SIL itself. So this hack can be removed.
As an additional benefit, this will let me rename -enable-sil-ownership to
-enable-sil-ownership-verifier. This will I hope eliminate confusion around this
option in the short term while I am preparing to work on semantic sil again.
rdar://42509812
It was only used in a few tests. Those tests now use -emit-sil instead
of -emit-silgen, with some functions marked @_transparent and a few
CHECK: lines changed now that the mandatory optimizations get to run.
Also, add a third [serializable] state for functions whose bodies we
*can* serialize, but only do so if they're referenced from another
serialized function.
This will be used for bodies synthesized for imported definitions,
such as init(rawValue:), etc, and various thunks, but for now this
change is NFC.
This ensures that we can write FileCheck patterns that match the end of sil
functions. Just using a FileCheck pattern against a brace is not sufficient in
the context of checking the SIL emitted by SILGen. This is because we could match a
different function's body and match the closing brace against the other
function's end brace.
With this change, one can be specific by checking:
// CHECK: } {{.*}} end sil function '<mangled name>'
The inspiration for this change is rdar://28685236. While updating SILGen tests
for that I have found many instances of SILGen tests pattern matching against
the wrong function bodies. This change will allow me to eliminate these problems
robustly.
rdar://29077869
