Noncopyable types may have user-defined code in their `deinit`s that requires
passing the type's generic parameters, so a box for a captured noncopyable type
needs to capture the generic environment even when the captured type is fixed-
layout. Fixes rdar://138958210.
For types like `Atomic` and `Mutex`, we want to know that even though they are
technically bitwise-takable, they differ from other bitwise-takable types until
this point because they are not also "bitwise-borrowable"; while borrowed,
they are pinned in memory, so they cannot be passed by value as a borrowed
parameter, unlike copyable bitwise-takable types. Add a bit to the value witness
table flags to record this.
Note that this patch does not include any accompanying runtime support for
propagating the flag into runtime-instantiated type metadata. There isn't yet
any runtime functionality that varies based on this flag, so that can
be implemented separately.
rdar://136396806
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
Although I don't plan to bring over new assertions wholesale
into the current qualification branch, it's entirely possible
that various minor changes in main will use the new assertions;
having this basic support in the release branch will simplify that.
(This is why I'm adding the includes as a separate pass from
rewriting the individual assertions)
Call `swift_clearSensitive` after destroying or taking "sensitive" struct types.
Also, support calling C-functions with "sensitive" parameters or return values. In SIL, sensitive types are address-only and so are sensitive parameters/return values.
Though, (small) sensitive C-structs are passed directly to/from C-functions. We need re-abstract such parameter and return values for C-functions.
An empty struct that is noncopyable can nonetheless have a `deinit`, so
it is not trivially destructible. In such cases, embedded them in
another empty struct means that the outer struct should also not be
trivially destructible. Make it so.
First, "can have an absence of Copyable" is a rather confusing notion,
so the query is flipped to "can be Copyable". Next, it's more robust to
ask if a conformance exists for the TypeDecl to answer that question,
rather than trying to replicate what happens within that conformance
lookup.
Also renames `TypeDecl::isEscapable` to match.
Conflicts:
- `lib/AST/TypeCheckRequests.cpp` renamed `isMoveOnly` which requires
a static_cast on rebranch because `Optional` is now a `std::optional`.
I've renamed the method to `TypeDecl::isNoncopyable`, because the query
doesn't make sense for many other kinds of `ValueDecl`'s beyond the
`TypeDecl`'s. In fact, it looks like no one was relying on that anyway.
Thus, we now have a distinction where in Sema, you ask whether
a `Type` or `TypeDecl` is "Noncopyable". But within SIL, we still
preserve the notion of "move-only" since there is additionally the
move-only type wrapper for types that otherwise support copying.
This attribute can be attached to a noncopyable struct to specify that its
storage is raw, meaning the type definition is (with some limitations)
able to do as it pleases with the storage. This provides a basis for
implementing types for things like atomics, locks, and data structures
that use inline storage to store conditionally-initialized values.
The example in `test/Prototypes/UnfairLock.swift` demonstrates the use
of a raw layout type to wrap Darwin's `os_unfair_lock` APIs, allowing
a lock value to be stored inside of classes or other types without
needing a separate allocation, and using the borrow model to enforce
safe access to lock-guarded storage.
* [Executors][Distributed] custom executors for distributed actor
* harden ordering guarantees of synthesised fields
* the issue was that a non-default actor must implement the is remote check differently
* NonDefaultDistributedActor to complete support and remote flag handling
* invoke nonDefaultDistributedActorInitialize when necessary in SILGen
* refactor inline assertion into method
* cleanup
* [Executors][Distributed] Update module version for NonDefaultDistributedActor
* Minor docs cleanup
* we solved those fixme's
* add mangling test for non-def-dist-actor
And use the new bit to ensure we don't try to lower move-only types
with common layout value witness surrogates. Take a bit in the runtime
value witness flags to represent types that are not copyable.
Noncopyable types aren't really "POD", but the bit is still useful to track
whether a noncopyable type has a no-op destroy operation, so rename the
existing bit to be more specific within IRGen's implementation.
Don't rename it in the runtime or Builtin names yet, since doing so will
require a naming transition for compatibility.
`getValue` -> `value`
`getValueOr` -> `value_or`
`hasValue` -> `has_value`
`map` -> `transform`
The old API will be deprecated in the rebranch.
To avoid merge conflicts, use the new API already in the main branch.
rdar://102362022
In preparation for moving to llvm's opaque pointer representation
replace getPointerElementType and CreateCall/CreateLoad/Store uses that
dependent on the address operand's pointer element type.
This means an `Address` carries the element type and we use
`FunctionPointer` in more places or read the function type off the
`llvm::Function`.
`PointerType::getElementType` has been removed entirely as part of the
opaque pointers migration. Update to `getPointerElementType` for now
until we've also migrated.
Since these types have an implicit stored property, this requires
adding an abstraction over fields to IRGen, at least throughout
the class code. In some ways I think this significantly improves
the code, especially in how we approach missing members.
Fixes rdar://72202671.
of adding a property.
This better matches what the actual implementation expects,
and it avoids some possibilities of weird mismatches. However,
it also requires special-case initialization, destruction, and
dynamic-layout support, none of which I've added yet.
In order to get NSObject default actor subclasses to use Swift
refcounting (and thus avoid the need for the default actor runtime
to generally use ObjC refcounting), I've had to introduce a
SwiftNativeNSObject which we substitute as the superclass when
inheriting directly from NSObject. This is something we could
do in all NSObject subclasses; for now, I'm just doing it in
actors, although it's all actors and not just default actors.
We are not yet taking advantage of our special knowledge of this
class anywhere except the reference-counting code.
I went around in circles exploring a number of alternatives for
doing this; at one point I basically had a completely parallel
"ForImplementation" superclass query. That proved to be a lot
of added complexity and created more problems than it solved.
We also don't *really* get any benefit from this subclassing
because there still wouldn't be a consistent superclass for all
actors. So instead it's very ad-hoc.
When the first element in the heap layout was non fixed we would use the
mininum size of the total heap layout for the initial offset. This would
create unneccessary large heap layouts.
rdar://61716736
This change modifies spare bit masks so that they are arranged in
the byte order of the target platform. It also modifies and
consolidates the code that gathers and scatters bits into enum
values.
All enum-related validation tests are now passing on IBM Z (s390x)
which is a big-endian platform.
Wait until we know the full size of the SpareBitVector before we
construct it from the spare bit masks of the individual elements
in the struct. This process mirrors the way we construct the rest
of the struct type.
This should reduce the number of short-lived allocations required
to build small struct types (especially after #25240). It also
provides a convenient place to insert code to handle the
construction of big-endian bit masks on when targeting big-endian
machines, assuming we decide to go down that route.
Field offset vectors are always filled out with either zero or the static layout's offset, depending on the metadata initialization strategy. This change means that the static layout's offset will only be non-zero for properties with a statically-known layout. Existing runtimes doing dynamic class layout assign class properties a zero offset if the field offset vector entry is zero and the property is zero-sized. So this effectively brings the compiler into accord with the runtime (for all newly-compiled Swift code, which will eventually be all Swift code because the current public releases of Swift 5 are not yet considered ABI-stable) and guarantees a zero value for the offset everywhere.
Since the runtime will agree with the compiler about the zero value of the offset, the compiler can continue to emit such offset variables as constant. The exception to this rule is if the class has non-fragile ObjC ancestry, in which case the ObjC runtime (which is not aware of this special rule for empty fields) will attempt to slide it along with everything else.
Fixes rdar://48031465, in which the `FixedClassMetadataBuilder` for a class with a legacy-fixed layout was writing a non-zero offset for an empty field into the field offset vector, causing the runtime to not apply the special case and thus to compute a non-zero offset, which it then attempted to copy into the global field offset variable, which the compiler had emitted as a true-constant zero.
The type info for a class described its layout using a combination of a
StructLayout and ClassLayout, with different information stored in both.
Since we never use a class as a struct, it's simpler to add the relevant
bits to ClassLayout, and not build a StructLayout at all.
Also, drop inherited properties from the ClassLayout -- they're no
longer needed.
