When storing a closure with type `() throws(any Error) -> ()` as
a fully opaque error, we want to leave it unchanged, instead of
re-abstracting it to throw the error indirectly. Thus, we had
a special carveout here.
However, the carveout was too broad, because if the thrown error
type contained type parameters, the resulting AbstractionPattern
was invalid.
While fixing this I realized this entire hack is unsound in some
cases, if you view the same value as a `() throws(U) -> ()` vs
an `() -> throws(any Error) -> ()`.
Perhaps we should always box the thrown error when maximally
abstracting a closure, but that would also be an ABI break.
- Fixes https://github.com/swiftlang/swift/issues/84051
When a generic function has potentially Escapable outputs, those outputs
declare lifetime dependencies, which have no effect when substitution
leads to those types becoming `Escapable` in a concrete context.
This means that type substitution should canonically eliminate lifetime
dependencies targeting Escapable parameters or returns, and that
type checking should allow a function value with potentially-Escapable
lifetime dependencies to bind to a function type without those dependencies
when the target of the dependencies is Escapable.
Fixes rdar://147533059.
To ensure that dependent values have a persistent-enough memory representation
to point into, when an immutable binding is referenced as an addressable
argument to a call, have SILGen retroactively emit a stack allocation and
materialization that covers the binding's scope.
To ensure that dependent values have a persistent-enough memory representation
to point into, when an immutable binding is referenced as an addressable
argument to a call, have SILGen retroactively emit a stack allocation and
materialization that covers the binding's scope.
This attribute makes it so that a parameter of the annotated type, as well as
any type structurally containing that type as a field, becomes passed as
if `@_addressable` if the return value of the function has a dependency on
the parameter. This allows nonescapable values to take interior pointers into
such types.
`Builtin.FixedArray<let N: Int, T: ~Copyable & ~Escapable>` has the layout of `N` elements of type `T` laid out
sequentially in memory (with the tail padding of every element occupied by the array). This provides a primitive
on which the standard library `Vector` type can be built.
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)
Factor AbstractionPattern::conformsToKnownProtocol and lower ~Escapable using the same logic as ~Copyable.
Adds support for conditionally Escapable enums.
Correctly sets the SILType::isTrivial flags for conditionally escapable structs and enums in environments (extensions)
that provide an Escapable conformance, such as:
struct NE<E: ~Escapable> : ~Escapable {}
extension NE: Escapable {
func foo() -> Self {
// Self is both Escapable and trivial here.
self
}
}
Fixes rdar://125950218 ([nonescapable] support conditionally escapable enums)
This fixes TypeLowering for ~Copyable generics, such as:
struct S<T: ~Copyable>: ~Copyable {
var x: T
}
extension S: Copyable where T: Copyable {}
func foo<T>(s: S<T>) -> ()
Previously, TypeLowering would ignore the implicit Copyable
requirement on the archetype 'T'.
When a closure throws a generic error type, we were retrieving the
substituted error type (involving archetypes) when we needed to be
working with the interface type.
Fixes rdar://124484012.
We want a conditionally-copyable type to still be classified as trivial in cases
where it's bitwise-copyable, has a trivial deinit, and is Copyable. The previous
implementation here only checked at the declaration level whether a type was
Copyable or not; get a more accurate answer by consulting the combination
of information in the substituted type and abstraction pattern we have
available during type lowering so that we classify definitely-copyable substitutions
of a conditionally-copyable type as trivial. Should fix rdar://123654553 and
rdar://123658878.
The main piece that's still missing here is support for closures;
they actually mostly work, but they infer the wrong isolation for
actor-isolated closures (it's not expressed in the type, so obviously
they're non-isolated), so it's not really functional. We also have
a significant problem where reabstraction thunks collide incorrectly
because we don't mangle (or represent!) formal isolation into
SILFunctionType; that's another follow-up. Otherwise, I think SILGen
is working.
rdar://119329771
This layout allows adding pre-specializations for trivial types that have a different size, but the same stride. This is especially useful for collections, where the stride is the important factor.
We were attempting to perform substitution against the original pattern
even when it didn't have a substitution map, and then trying to cover
for the resulting errors by adjusting to `any Error`... which isn't
always correct. Do the substitution only when it makes sense.
Fixes rdar://119217570 & rdar://119219214.
This peephole optimization in SILGen requires us to use the thrown
error for the context of a closure type rather than the thrown error
for the closure AST node itself.
If the pattern doesn't have any pack parameters in it anymore,
we need to recover the substituted count type from the original
count type.
Fixes rdar://problem/112065340.
Reformatting everything now that we have `llvm` namespaces. I've
separated this from the main commit to help manage merge-conflicts and
for making it a bit easier to read the mega-patch.
This is phase-1 of switching from llvm::Optional to std::optional in the
next rebranch. llvm::Optional was removed from upstream LLVM, so we need
to migrate off rather soon. On Darwin, std::optional, and llvm::Optional
have the same layout, so we don't need to be as concerned about ABI
beyond the name mangling. `llvm::Optional` is only returned from one
function in
```
getStandardTypeSubst(StringRef TypeName,
bool allowConcurrencyManglings);
```
It's the return value, so it should not impact the mangling of the
function, and the layout is the same as `std::optional`, so it should be
mostly okay. This function doesn't appear to have users, and the ABI was
already broken 2 years ago for concurrency and no one seemed to notice
so this should be "okay".
I'm doing the migration incrementally so that folks working on main can
cherry-pick back to the release/5.9 branch. Once 5.9 is done and locked
away, then we can go through and finish the replacement. Since `None`
and `Optional` show up in contexts where they are not `llvm::None` and
`llvm::Optional`, I'm preparing the work now by going through and
removing the namespace unwrapping and making the `llvm` namespace
explicit. This should make it fairly mechanical to go through and
replace llvm::Optional with std::optional, and llvm::None with
std::nullopt. It's also a change that can be brought onto the
release/5.9 with minimal impact. This should be an NFC change.
variadic-tuple results. There are three parts to this.
First, fix the emission of indirect result parameters to do a
proper abstraction-pattern-aware traversal of tuple patterns.
There was a FIXME here and everything.
Second, fix the computation of substituted abstraction
patterns to properly handle vanishing tuples. The previous code
was recursively destructuring tuples, but only when it saw a
tuple as the substituted type, which of course breaks on vanishing
tuples.
Finally, fix the emission of returns into vanishing tuple
patterns by allowing the code to not produce a TupleInitialization
when the tuple pattern vanishes. We should always get a singleton
element initializer in this case.
Fixes rdar://109843932, plus a closely-related test case for
vanishing tuples that I added myself.
