* Use in_guaranteed for let captures
With this all let values will be captured with in_guaranteed convention
by the closure. Following are the main changes :
SILGen changes:
- A new CaptureKind::Immutable is introduced, to capture let values as in_guaranteed.
- SILGen of in_guaranteed capture had to be fixed.
in_guaranteed captures as per convention are consumed by the closure. And so SILGen should not generate a destroy_addr for an in_guaranteed capture.
But LetValueInitialization can push Dealloc and Release states of the captured arg in the Cleanup stack, and there is no way to access the CleanupHandle and disable the emission of destroy_addr while emitting the captures in SILGenFunction::emitCaptures.
So we now create, temporary allocation of the in_guaranteed capture iduring SILGenFunction::emitCaptures without emitting destroy_addr for it.
SILOptimizer changes:
- Handle in_guaranteed in CopyForwarding.
- Adjust dealloc_stack of in_guaranteed capture to occur after destroy_addr for on_stack closures in ClosureLifetimeFixup.
IRGen changes :
- Since HeapLayout can be non-fixed now, make sure emitSize is used conditionally
- Don't consider ClassPointerSource kind parameter type for fulfillments while generating code for partial apply forwarder.
The TypeMetadata of ClassPointSource kind sources are not populated in HeapLayout's NecessaryBindings. If we have a generic parameter on the HeapLayout which can be fulfilled by a ClassPointerSource, its TypeMetaData will not be found while constructing the dtor function of the HeapLayout.
So it is important to skip considering sources of ClassPointerSource kind, so that TypeMetadata of a dependent generic parameters gets populated in HeapLayout's NecessaryBindings.
In order to allow this, I've had to rework the syntax of substituted function types; what was previously spelled `<T> in () -> T for <X>` is now spelled `@substituted <T> () -> T for <X>`. I think this is a nice improvement for readability, but it did require me to churn a lot of test cases.
Distinguishing the substitutions has two chief advantages over the existing representation. First, the semantics seem quite a bit clearer at use points; the `implicit` bit was very subtle and not always obvious how to use. More importantly, it allows the expression of generic function types that must satisfy a particular generic abstraction pattern, which was otherwise impossible to express.
As an example of the latter, consider the following protocol conformance:
```
protocol P { func foo() }
struct A<T> : P { func foo() {} }
```
The lowered signature of `P.foo` is `<Self: P> (@in_guaranteed Self) -> ()`. Without this change, the lowered signature of `A.foo`'s witness would be `<T> (@in_guaranteed A<T>) -> ()`, which does not preserve information about the conformance substitution in any useful way. With this change, the lowered signature of this witness could be `<T> @substituted <Self: P> (@in_guaranteed Self) -> () for <A<T>>`, which nicely preserves the exact substitutions which relate the witness to the requirement.
When we adopt this, it will both obviate the need for the special witness-table conformance field in SILFunctionType and make it far simpler for the SILOptimizer to devirtualize witness methods. This patch does not actually take that step, however; it merely makes it possible to do so.
As another piece of unfinished business, while `SILFunctionType::substGenericArgs()` conceptually ought to simply set the given substitutions as the invocation substitutions, that would disturb a number of places that expect that method to produce an unsubstituted type. This patch only set invocation arguments when the generic type is a substituted type, which we currently never produce in type-lowering.
My plan is to start by producing substituted function types for accessors. Accessors are an important case because the coroutine continuation function is essentially an implicit component of the function type which the current substitution rules simply erase the intended abstraction of. They're also used in narrower ways that should exercise less of the optimizer.
Teach RemoteMirror how to project enum values
This adds two new functions to the SwiftRemoteMirror
facility that support inspecting enum values.
Currently, these support non-payload enums and
single-payload enums, including nested enums and
payloads with struct, tuple, and reference payloads.
In particular, it handles nested `Optional` types.
TODO: Multi-payload enums use different strategies for
encoding the cases that aren't yet supported by this
code.
Note: This relies on information from dataLayoutQuery
to correctly decode invalid pointer values that are used
to encode enums. Existing clients will need to augment
their DLQ functions before using these new APIs.
Resolves rdar://59961527
```
/// Projects the value of an enum.
///
/// Takes the address and typeref for an enum and determines the
/// index of the currently-selected case within the enum.
///
/// Returns true iff the enum case could be successfully determined.
/// In particular, note that this code may fail for valid in-memory data
/// if the compiler is using a strategy we do not yet understand.
SWIFT_REMOTE_MIRROR_LINKAGE
int swift_reflection_projectEnumValue(SwiftReflectionContextRef ContextRef,
swift_addr_t EnumAddress,
swift_typeref_t EnumTypeRef,
uint64_t *CaseIndex);
/// Finds information about a particular enum case.
///
/// Given an enum typeref and index of a case, returns:
/// * Typeref of the associated payload or zero if there is no payload
/// * Name of the case if known.
///
/// The Name points to a freshly-allocated C string on the heap. You
/// are responsible for freeing the string (via `free()`) when you are finished.
SWIFT_REMOTE_MIRROR_LINKAGE
int swift_reflection_getEnumCaseTypeRef(SwiftReflectionContextRef ContextRef,
swift_typeref_t EnumTypeRef,
unsigned CaseIndex,
char **CaseName,
swift_typeref_t *PayloadTypeRef);
```
Co-authored-by: Mike Ash <mikeash@apple.com>
If an enum has a payload case with zero size, we treat it as an empty case
for ABI purposes. Unfortunately, this meant that reflection metadata was
incomplete for such cases, with a Mirror reporting that the enum value
had zero children.
Tweak the field type metadata emission slightly to preserve the payload
type for such enum cases.
Fixes <https://bugs.swift.org/browse/SR-12044> / <rdar://problem/58861157>.
In particular, this fixes the size calculation for nested enums,
specifically enums within Optionals. Without this, the
reflection library computes `v` below as requiring two bytes
instead of one.
```
enum E {
case a
case b
}
let v = Optional<E>
```
This also adds a number of test cases for enums alone and
wrapped in optionals, including:
* Zero-case enums are allocated zero size and have zero extra inhabitants
* Zero-case enums in optionals also get zero size
* One-case no-payload enums are allocated zero size and have zero extra inhabitants
* One-case no-payload enums in optionals get one byte allocated and have zero extra inhabitants
* 254-case enums have only two extra inhabitants, so putting them in thrice-nested optionals requires an extra byte
* Various cases where each nested optional gets an extra byte
Resolves rdar://31154770
In order for the cross-module optimization to work, it needs to generate
symbolic references, which were disabled in PE/COFF. This commit enables
them and marks some Reflection tests with XFAIL since
swift-reflection-dump still doesn't handle symbolic references.
Collect the relative and symbol relocations from ELF images in order to resolve pointer values
read from disk. This allows us to enable symbolic-referencing-all-the-things for ELF platforms.
As the base of the "remote" address space ObjectMemoryReader presents for an image, use the
image's own preferred VM address mappings. If there are multiple images loaded, differentiate
them by using the top 16 bits of the remote address space as an index into the array of images.
This should make it so that absolute pointers in the file Just Work without sliding in most
cases; we'd only need to mix in the image index in order to have a value that is also a valid
remote address.
If somebody called `demangleType` or `demangleSymbol` using a demangler that was already
in the middle of demangling a string, then the state for the new demangler would clobber the old
demangler. This manifested in rdar://problem/50380275 because, as part of demangling a
string with a symbolic reference to a private type's context, we would demangle the debug string
for the referenced context using the same demangler. If there were additional operators in the
original string after the symbolic reference, these never got demangled because the demangler
was now in the state of having completed demangling the other string, so we would drop nesting,
and incorrectly report field types of, for instance, `Array<PrivateStruct>` or
`(PrivateStruct, OtherStruct)` as just being `PrivateStruct`.
This is a likely situation to be in, especially now that `Demangler` objects also serve as
arena allocators for their demangled nodes, so change the top-level demangler entry points
to use an RAII object to push and pop the existing state instead of unilaterally clobbering
the existing state.
Previously even if a type's metadata was optimized away, we would still
emit a field descriptor, which in turn could reference nominal type
descriptors for other types via symbolic references, etc.
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.
The naming convention is different on Windows than on Unix-like
environments. In order to follow the convention we need to substitute
the prefix and the suffix. Take the opportunity to rename the
`target-dylib-extension` to the CMake-like variable
`target-shared-library-suffix` and introduce
`target-shared-library-prefix`. This helps linking the test suite
binaries on Windows.
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
Previously, they would forward their unused spare bits to be used by other multi-payload enums, but
did not implement anything for single-payload extra inhabitants.
Bitwise takability is now part of the layout of a type, because
non-bitwise takable types are never stored inline in an
existential or resilient global's buffer, even if they would
fit.
The basic rule is that weak references, unknown-refcounted
unowned references, and aggregates that contain them, are not
bitwise takable, whereas everything else is bitwise takable.
Also, since the bitwise takable for an unowned reference
depends on the reference counting style, we have to record the
superclass of a protocol, if any, to correctly determine the
reference counting style of the protocol existential.
Right now we expect that every class and protocol has a field
descriptor that tells us if the entity is @objc or not.
For imported types, the descriptor will not exist if we did not
directly emit a field whose concrete type contains the imported
type. For example, in lldb, we might have a generic type whose
runtime substituted type includes an imported type.
In this case, TypeLowering would fail to produce a layout because
it did not find a field descriptor for the imported type.
A better approach is to have the TypeDecoder call a different
factory method for imported types, and handle them specially in
TypeLowering, bypassing the field type metadata altogether.
Extending the mangling of symbolic references to also include indirect
symbolic references. This allows mangled names to refer to context
descriptors (both type and protocol) not in the current source file.
For now, only permit indirect symbolic references within the current module,
because remote mirrors (among other things) is unable to handle relocations.
Co-authored-by: Joe Groff <jgroff@apple.com>
We can use the extra inhabitants of the type metadata field as extra inhabitants of the entire
existential container, allowing `Any?` and similar types to be the same size as non-optional
existentials.
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
The TypeDecoder doesn't support the new box mangling yet and instead
just decodes it as Builtin.NativeObject, but that's OK because the
Remote Mirrors lowered the old box mangling as Builtin.NativeObject
anyway.
I am going to leave in the infrastructure around this just in case. But there is
no reason to keep this in the tests themselves. I can always just revert this
and I don't think merge conflicts are likely due to previous work I did around
the tooling for this.
We were hoping to use these to allow for plus_zero to be easily reverted. It
turns out that it took more tooling/time than we inticipated, so I am going back
to the old way of doing things. So remove the dead tests.
rdar://34222540
