rdar://127379960
When the spare bits of an Error objects are used to store tag bits, this caused the enum tag to be lost, which caused the wrong enum cases to be matched.
Merge the three-stage operation originally designed for field vectors into a single unified loop that acts directly on the ivar offsets instead of using a faux field offset vector.
We really don’t need ‘em; we can just adjust the direct field offsets.
The runtime entry point currently uses a weird little hack that we will refactor away shortly.
When an @objc @implementation class requires the use of `ClassMetadataStrategy::Update` because some of its stored properties do not have fixed sizes, we adjust the direct field offsets during class realization by emitting a custom metadata update function which calls a new entry point in the Swift runtime. That entry point adjusts field offsets like `swift_updateClassMetadata2()`, but it only assumes that the class has Objective-C metadata, not Swift metadata.
This commit introduces an alternative mechanism which does the same thing without using any Swift-only metadata. It’s a rough implementation with important limitations:
• We’re currently using the field offset vector, which means that field offsets are being emitted into @objc @implementation classes; these will be removed.
• The new Swift runtime entry point duplicates a lot of `swift_updateClassMetadata2()`’s implementation; it will be refactored into something much smaller and more compact.
• Availability bounds for this feature have not yet been implemented.
Future commits in this PR will correct these issues.
We attempted to use the declaration if it exists, and fall back to dlsym. This didn't actually work and we always call dlsym. Include the right header (when available) and add a weak check to the direct call.
rdar://127116080
* [Runtime] Fix CVW for genreic single payload enums with no extra inhabitants
rdar://126728925
When the payload of a generic SPE did not have any extra inhabitants, we erroneously always treated it as the no payload case.
Additionally the offset and skip values were improperly computed.
* Fixed FileCheck string
The pointer location can be computed from the symbolic reference location and offset, which we already provide, but it's not clear that you should add them together, nor is it clear why this failure would occur. Add the location of the NULL pointer itself to the error message, and also mention that it's probably caused by a missing weak symbol.
Read a list of disabled process names from the prespecializations library, and turn the feature off if the current process matches. Also allow passing process names in environment variables. Processes can be disabled by name using SWIFT_DEBUG_LIB_PRESPECIALIZED_DISABLED_PROCESSES, and a disable can be overridden with SWIFT_DEBUG_LIB_PRESPECIALIZED_ENABLED_PROCESSES.
rdar://126216786
type(of:) now returns the dynamic type of the contents of
an extended existential (just like it does for a regular existential)
Mirror can now reflect fields of a value stored inside an extended
existential (just like it can with a regular existential). This
requires type(of:) support, since Mirror internals use that to
determine how to reflect a value.
Resolves rdar://102906195
WebAssembly does not support _Float16 type, so we need to guard the use
of the type. Unfortunately, Clang does not provide a good way to detect
the support of _Float16 type at compile time, so just disable for wasm
targets.
We can easily test all 2**16 values, so let's do it. Also now _Float16 is properly supported in clang, so we can pass arguments to CPP that way, which lets us get snan right on more platforms.
This introduces a non-Darwin (non-CrashReporter) storage for error
messages to allow extraction for crash reporting. This is initially
meant to be used on Windows, though it is generic enough to be used on
any platform.
The descriptor and arguments for prespecialized metadata will always be in the shared cache. Skip creating the mangling for any lookup involving pointers outside the shared cache, as an optimization.
This PR implements first set of changes required to support autodiff for coroutines. It mostly targeted to `_modify` accessors in standard library (and beyond), but overall implementation is quite generic.
There are some specifics of implementation and known limitations:
- Only `@yield_once` coroutines are naturally supported
- VJP is a coroutine itself: it yields the results *and* returns a pullback closure as a normal return. This allows us to capture values produced in resume part of a coroutine (this is required for defers and other cleanups / commits)
- Pullback is a coroutine, we assume that coroutine cannot abort and therefore we execute the original coroutine in reverse from return via yield and then back to the entry
- It seems there is no semantically sane way to support `_read` coroutines (as we will need to "accept" adjoints via yields), therefore only coroutines with inout yields are supported (`_modify` accessors). Pullbacks of such coroutines take adjoint buffer as input argument, yield this buffer (to accumulate adjoint values in the caller) and finally return the adjoints indirectly.
- Coroutines (as opposed to normal functions) are not first-class values: there is no AST type for them, one cannot e.g. store them into tuples, etc. So, everywhere where AST type is required, we have to hack around.
- As there is no AST type for coroutines, there is no way one could register custom derivative for coroutines. So far only compiler-produced derivatives are supported
- There are lots of common things wrt normal function apply's, but still there are subtle but important differences. I tried to organize the code to enable code reuse, still it was not always possible, so some code duplication could be seen
- The order of how pullback closures are produced in VJP is a bit different: for normal apply's VJP produces both value and pullback closure via a single nested VJP apply. This is not so anymore with coroutine VJP's: yielded values are produced at `begin_apply` site and pullback closure is available only from `end_apply`, so we need to track the order in which pullbacks are produced (and arrange consumption of the values accordingly – effectively delay them)
- On the way some complementary changes were required in e.g. mangler / demangler
This patch covers the generation of derivatives up to SIL level, however, it is not enough as codegen of `partial_apply` of a coroutine is completely broken. The fix for this will be submitted separately as it is not directly autodiff-related.
---------
Co-authored-by: Andrew Savonichev <andrew.savonichev@gmail.com>
Co-authored-by: Richard Wei <rxwei@apple.com>
We need to check for overridden images on every image load, otherwise
XCTest (among others) may `dlopen()` an image that pulls in something
that is overridden, at which point the prespecialized metadata won't
match the image we loaded.
rdar://125727356
Emit metadata for runtime checks of conformances of associated types to
invertible protocols, e.g., `T.Assoc: Copyable`. This allows us to
correctly handle, e.g., dynamic casting involving conditional
conformances that have such constraints.
The model we use here is to emit an invertible-protocol constraint
that leaves only the specific bit clear in the invertible protocol
set.
When we fail to look up a type by name, we print an error, then try to compare anyway, which crashes. Skip the comparison when that happens.
While we're in there, modify _swift_validatePrespecializedMetadata to be more useful for debugging, by removing the parameters and having it print the results directly.
Form a set of suppressed protocols for a function type based on
the extended flags (where future compilers can start recording
suppressible protocols) and the existing "noescape" bit. Compare
that against the "ignored" suppressible protocol requirements, as we
do for other types.
This involves a behavior change if any client has managed to evade the
static checking for noescape function types, but it's unlikely that
existing code has done so (and it was unsafe anyway).
Add more runtime support for checking suppressible protocol requirements:
* Parameter packs now check all of the arguments appropriately
* Most structural types now implement checking (these are hard to test).
Introduce metadata and runtime support for describing conformances to
"suppressible" protocols such as `Copyable`. The metadata changes occur
in several different places:
* Context descriptors gain a flag bit to indicate when the type itself has
suppressed one or more suppressible protocols (e.g., it is `~Copyable`).
When the bit is set, the context will have a trailing
`SuppressibleProtocolSet`, a 16-bit bitfield that records one bit for
each suppressed protocol. Types with no suppressed conformances will
leave the bit unset (so the metadata is unchanged), and older runtimes
don't look at the bit, so they will ignore the extra data.
* Generic context descriptors gain a flag bit to indicate when the type
has conditional conformances to suppressible protocols. When set,
there will be trailing metadata containing another
`SuppressibleProtocolSet` (a subset of the one in the main context
descriptor) indicating which suppressible protocols have conditional
conformances, followed by the actual lists of generic requirements
for each of the conditional conformances. Again, if there are no
conditional conformances to suppressible protocols, the bit won't be
set. Old runtimes ignore the bit and any trailing metadata.
* Generic requirements get a new "kind", which provides an ignored
protocol set (another `SuppressibleProtocolSet`) stating which
suppressible protocols should *not* be checked for the subject type
of the generic requirement. For example, this encodes a requirement
like `T: ~Copyable`. These generic requirements can occur anywhere
that there is a generic requirement list, e.g., conditional
conformances and extended existentials. Older runtimes handle unknown
generic requirement kinds by stating that the requirement isn't
satisfied.
Extend the runtime to perform checking of the suppressible
conformances on generic arguments as part of checking generic
requirements. This checking follows the defaults of the language, which
is that every generic argument must conform to each of the suppressible
protocols unless there is an explicit generic requirement that states
which suppressible protocols to ignore. Thus, a generic parameter list
`<T, Y where T: ~Escapable>` will check that `T` is `Copyable` but
not that it is `Escapable`, and check that `U` is both `Copyable` and
`Escapable`. To implement this, we collect the ignored protocol sets
from these suppressed requirements while processing the generic
requirements, then check all of the generic arguments against any
conformances not suppressed.
Answering the actual question "does `X` conform to `Copyable`?" (for
any suppressible protocol) looks at the context descriptor metadata to
answer the question, e.g.,
1. If there is no "suppressed protocol set", then the type conforms.
This covers types that haven't suppressed any conformances, including
all types that predate noncopyable generics.
2. If the suppressed protocol set doesn't contain `Copyable`, then the
type conforms.
3. If the type is generic and has a conditional conformance to
`Copyable`, evaluate the generic requirements for that conditional
conformance to answer whether it conforms.
The procedure above handles the bits of a `SuppressibleProtocolSet`
opaquely, with no mapping down to specific protocols. Therefore, the
same implementation will work even with future suppressible protocols,
including back deployment.
The end result of this is that we can dynamically evaluate conditional
conformances to protocols that depend on conformances to suppressible
protocols.
Implements rdar://123466649.
Extend TypeDecoder with support for inverse requirements, passing them
along to the type builder. Then implement support for inverse
requirements within the AST demangler, which addresses the round-trip
demangling failures we've been seeing.
The runtime and remote inspection facilities still need metadata to
deal with inverse requirements.
Fixes rdar://124564447.
LLVM is presumably moving towards `std::string_view` -
`StringRef::startswith` is deprecated on tip. `SmallString::startswith`
was just renamed there (maybe with some small deprecation inbetween, but
if so, we've missed it).
The `SmallString::startswith` references were moved to
`.str().starts_with()`, rather than adding the `starts_with` on
`stable/20230725` as we only had a few of them. Open to switching that
over if anyone feels strongly though.
We can't use os_log functionality in logd, diagnosticd, or notifyd. Check for them and disable tracing in those processes.
Add a new TracingCommon.h for common code shared between swiftCore and swift_Concurrency tracing. Add a single function that checks if tracing should be enabled, which now checks if os_signpost_enabled is available, and if the process is one of these. Modify the tracing code to check this before creating os_log objects.
rdar://124226334
We were retaining one too many times in the two `_DeathTest` tests,
which caused the tests to fail. This was previously masked by a bug.
rdar://124212794
Fix overflow detection on unowned refcounts so that we create a side table when incrementing from 126. Implement strong refcount overflow to the side table.
The unowned refcount is never supposed to be 127, because that (sometimes) represents the immortal refcount. We attempt to detect that by checking newValue == Offsets::UnownedRefCountMask, but the mask is shifted so that condition is never true. We managed to hit the side table case when incrementing from 127, because it looks like the immortal case. But that broke when we fixed immortal side table initialization in b41079a8f54ae2d61c68cdda46c74232084af020. With that change, we now create an immortal side table when overflowing the unowned refcount, then try to increment the unowned refcount in that immortal side table, which traps.
rdar://123788910
