The descriptor map is keyed by a simplified mangling that canonicalizes the differences that we accept in _contextDescriptorMatchesMangling, such as the ability to specify any kind of type with an OtherNominalType node.
This simplified mangling is not necessarily unique, but we use _contextDescriptorMatchesMangling for the final equality checking when looking up entries in the map, so occasional collisions are acceptable and get resolved when probing the table.
The table is meant to be comprehensive, so it includes all descriptors that can be looked up by name, and a negative result means the descriptor does not exist in the shared cache. We add a flag to the options that can mark it as non-definitive in case we ever need to degrade this, and fall back to a full search after a negative result.
The map encompasses the entire shared cache but we need to reject lookups for types in images that aren't loaded. The map includes an image index which allows us to cheaply query whether a given descriptor is in a loaded image or not, so we can ignore ones which are not.
TypeMetadataPrivateState now has a separate sections array for sections within the shared cache. _searchTypeMetadataRecords consults the map first. If no result is found in the map and the map is marked as comprehensive, then only the sections outside the shared cache need to be scanned.
Replace the SWIFT_DEBUG_ENABLE_LIB_PRESPECIALIZED environment variable with one specifically for metadata and one for descriptor lookup so they can be controlled independently. Also add SWIFT_DEBUG_VALIDATE_LIB_PRESPECIALIZED_DESCRIPTOR_LOOKUP which consults the map and does the full scan, and ensures they produce the same result, for debugging purposes.
Enhance the environment variable code to track whether a variable was set at all. This allows SWIFT_DEBUG_ENABLE_LIB_PRESPECIALIZED to override the default in either direction.
Remove the disablePrespecializedMetadata global and instead modify the mapConfiguration to disable prespecialized metadata when an image is loaded that overrides one in the shared cache.
rdar://113059233
It cannot be used for executing general-purpose work, because such function would need to have a different signature to pass isolated actor instance.
And being explicit about using this method only for deinit allows to use object pointer for comparison with executor identity.
* [Concurrency] Fix task excutor handling of default actor isolation
The task executor API did not properly account for taking the default
actor locking into account when running code on it, we just took the job
and ran it without checking with the serial executor at all, which
resulted in potential concurrent executions inside the actor --
violating actor isolation.
Here we change the TaskExecutor enqueue API to accept the "target"
serial executor, which in practice will be either generic or a specific
default actor, and coordinate with it when we perform a
runSynchronously.
The SE proposal needs to be amended to showcase this new API, however
without this change we are introducing races so we must do this before
the API is stable.
* Remove _swift_task_enqueueOnTaskExecutor as we don't use it anymore
* no need for the new protocol requirement
* remove the enqueue(_ job: UnownedJob, isolatedTo unownedSerialExecutor: UnownedSerialExecutor)
Thankfully we dont need it after all
* Don't add swift_defaultActor_enqueue_withTaskExecutor and centralize the task executor getting to enqueue()
* move around extern definitions
This reverts c07aa9c425 which was done to
avoid a crash in optimnized caused by this PR:
https://github.com/apple/swift/pull/41088
Since this was almost 2 years ago, we probably don't have this issue
anymore as far as I can see other resolved issues, so try to remove the
workaround.
Resolves rdar://88711954
The existing lookup uses a hash table with the type's mangled name as the key. Building that key is costly. Add a new table that uses pointer keys, so that we can use the descriptor and arguments directly as the key.
rdar://127621414
Emitting a signpost for the first time can trigger lazy setup of the logging system, and doing this in the wrong context can cause deadlocks. Check to see if the logging system is already set up, and only emit signposts if it has been to avoid triggering this.
As it's hard to determine if the "is it set up?" function is available in the SDK we're building against, only do this in OS builds, as it's not particularly useful in local builds.
rdar://124620772
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.
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
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.
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.
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
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.
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.
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
Don't use `#cmakedefine` to define values that can be zero.
`#cmakedefine` only sets the definition when the corresponding value in
CMake itself has a truthy value. `0` has a false-y value, so
SWIFT_VERSION_MINOR is undefined for 6.0 resulting in some things
breaking.
