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
Following up from #71795, we must borrow the base of any non-copyable
`borrowing`/`nonmutating` accessor, and we want to borrow the base
of any accessor appearing in a `borrow` expr. Fixes#71606.
The reason why I am doing this is that I am going to be changing transferring to
not be a true ParamSpecifier. Instead, it is going to be a bit on Param that
changes the default ParamSpecifier used. That being said, I cannot use consuming
for this purpose since consuming today implies no implicit copy semantics, which
we do not want unless the user specifically asks for it by writing consuming.
A baked-in assumption was that the generic parameters of the KeyPath
family of types have no conformance requirements. That's no longer the
case with NoncopyableGenerics, so we need to dig up conformances when
forming the substitution map, as-needed.
The distributed-actor-as-actor conformance is synthesized by the
frontend, so make sure that when we access the API that exposes it
(asLocalActor), we be sure to mark the conformance as "used".
This is a very specific workaround for general problem with
compiler-synthesized conformances. SIL deserialization can bring in a
reference to a conformance late in the SIL pipeline, after the point at
which SILGen can create the conformance. We should be able to address
this systemically to remove the hack.
Mark the result of a move-only addressor as unresolved. The pointed-at value
cannot be consumed so ensure that only [read] or [modify] accesses are
performed. Update the move-only checker to recognize code patterns
from addressors.
A TypeExpr and other kinds of non-lvalue bases that the borrowed-base
visitor doesn't care about can be handled by calling back into the
original SILGenLValue instance.
resolves rdar://117082469
I think from SIL's perspective, it should only worry about whether the
type is move-only. That includes MoveOnlyWrapped SILTypes and regular
types that cannot be copied.
Most of the code querying `SILType::isPureMoveOnly` is in SILGen, where
it's very likely that the original AST type is sitting around already.
In such cases, I think it's fine to ask the AST type if it is
noncopyable. The clarity of only asking the ASTType if it's noncopyable
is beneficial, I think.
I was originally hoping to reuse mark_must_check for multiple types of checkers.
In practice, this is not what happened... so giving it a name specifically to do
with non copyable types makes more sense and makes the code clearer.
Just a pure rename.
In opaque values mode, emit the unowned copy instructions to convert as
follows:
strong_copy_unowned_value: `@owned $sil_unowned T` -> `@owned $T`
unowned_copy_value: `@owned T` -> `@owned $sil_unowned T`
Doing so is necessary in opaque values mode where it is needed to deal
with unowned values directly rather than indirectly via `load_unowned`s
and `store_unowned`s.
In opaque values mode, emit the new weak copy instructions to convert as
follows:
strong_copy_weak_value: `@owned $sil_weak T?` -> `@owned $T?`
weak_copy_value: `@owned $T?` -> `@owned $@sil_weak T?`
Doing so is necessary in opaque values mode where it is needed to deal
with weak values directly rather than indirectly via `load_weak`s and
`store_weak`s.
This is a futile attempt to discourage future use of getType() by
giving it a "scary" name.
We want people to use getInterfaceType() like with the other decl kinds.
When a value's preferred existential representation is opaque, if the
value is not an address (which can only happen in opaque values mode),
emit open_existential_value rather than open_existential_addr.
Also, the store_borrow work in the previous patch caused some additional issues
to crop up. I fixed them in this PR and added some tests in the process.
When setting a value at a key-path, in opaque values mode, don't create
a temporary and store the new value into it. That is necessary when
using lowered addresses because intrinsic's signature is
```
sil @swift_setAtWritableKeyPath : $@convention(thin) <τ_0_0, τ_0_1> (@inout τ_0_0, @guaranteed WritableKeyPath<τ_0_0, τ_0_1>, @in τ_0_1) -> ()
```
but is incorrect in opaque values mode where values are passed directly
to `@in` parameters.
This prevents another type of copy of noncopyable value error.
I also as a small change, changed the tuple version to use a formal access
temporary since we are projecting a component out implying that the lifetime of
the temporary must end within the formal access. Otherwise, we cause the
lifetime of the temporary to outlive the access. This can be seen in the change
to read_accessor.swift where we used to extend the lifetime of the destroy_addr
outside of the coroutine access we are performing.
We want these to be borrowed in most cases and to create an appropriate onion
wrapping. Since we are doing this in more cases now, we fix a bunch of cases
where we used to be forced to insert a copy since a coroutine or access would
end too early.
Instead of taking a setter type, let's switch over to a more general
`AccessorKind` which allows us to cover init accessors and simplify
`emitApplySetterToBase`.
This is a preliminary step towards enabling default initialization of
init accessor properties in user-defined initializers because this logic
would have to be shared by multiple places during SILGen.
Without this, we emit a copy of noncopyable type error since we do not insert a
mark_must_check on lazily initialized global initializers.
rdar://111402912
`Initialization` is stateful and not meant to be emitted into multiple times across different contexts.
If emitting into an initialization causes it to be split or aborted, that will carry over into
further uses of the initialization. This was happening during `if` and `switch` expression
emission, leading to miscompiles or compiler crashes. Fix this by saving only the buffer when
we prepare emission for a statement expression, and creating the initialization in the scope
where the expression for a branch actually gets emitted. Fixes rdar://112213253.
