When generic metadata for a class is requested in the same module where
the class is defined, rather than a call to the generic metadata
accessor or to a variant of typeForMangledNode, a call to a new
accessor--a canonical specialized generic metadata accessor--is emitted.
The new function is defined schematically as follows:
MetadataResponse `canonical specialized metadata accessor for C<K>`(MetadataRequest request) {
(void)`canonical specialized metadata accessor for superclass(C<K>)`(::Complete)
(void)`canonical specialized metadata accessor for generic_argument_class(C<K>, 1)`(::Complete)
...
(void)`canonical specialized metadata accessor for generic_argument_class(C<K>, count)`(::Complete)
auto *metadata = objc_opt_self(`canonical specialized metadata for C<K>`);
return {metadata, MetadataState::Complete};
}
where generic_argument_class(C<K>, N) denotes the Nth generic argument
which is both (1) itself a specialized generic type and is also (2) a
class. These calls to the specialized metadata accessors for these
related types ensure that all generic class types are registered with
the Objective-C runtime.
To enable these new canonical specialized generic metadata accessors,
metadata for generic classes is prespecialized as needed. So are the
metaclasses and the corresponding rodata.
Previously, the lazy objc naming hook was registered during process
execution when the first generic class metadata was instantiated. Since
that instantiation may occur "before process launch" (i.e. if the
generic metadata is prespecialized), the lazy naming hook is now
installed at process launch.
It needs to have the getFixedBufferAlignment because that is the value we use to determine whether the type
will be stored inline in the buffer or outline in an allocated buffer
rdar://62443743
`SynthesizedFileUnit` is a container for synthesized declarations. Currently, it
only supports module-level declarations.
It is used by the SIL differentiation transform, which generates implicit struct
and enum declarations.
This slightly regresses the standard library build (intentionally) while
generally improving the build of dispatch, foundation, xctest.
Rather than continuing to rely on the short-term hack of special casing
the standard library, identify the module where the decl originates
from. If the module is the current module, then assume that the symbol
need not be imported (static linking does not currently work on Windows
anyways). This allows for properly identifying the module where the
symbol will be homed.
Because we no longer special case the standard library here, a few known
metadata types will be incorrectly marked as being imported rather than
local.
Since linked entities which have `Shared` SILLinkage should be module
local, special case them to always be local. Without this the metadata
access function is still marked incorrectly.
With this computation we now get nearly all the cases correct. Dispatch
no longer has to rely on the linker relaxing the import to a local
binding. XCTest is also clean. Foundation misses the following case:
- `$sSS10FoundationE19_bridgeToObjectiveCAA8NSStringCyF`
The regressed cases in swiftCore are:
- `$sBi64_WV`
- `$sBi8_WV`
- `$sBi16_WV`
- `$sBi32_WV`
- `$sBpWV`
- `$syycWV`
- `$sBoWV`
- `$sBOWV`
- `$sBbWV`
- `$sytWV`
The logic here used to consist of a couple of ad-hoc checks,
followed by a general assumption that if something had already
been emitted, it could be referenced directly, whereas everything
else had to go through a GOT entry.
This is way too conservative. Instead, let's try to correctly
calculate what translation unit an entity is going to end up in.
SIL differentiability witnesses are a new top-level SIL construct mapping
an "original" SIL function and derivative configuration to derivative SIL
functions.
This patch adds `SILDifferentiabilityWitness` IRGen.
`SILDifferentiabilityWitness` has a fixed `{ i8*, i8* }` layout:
JVP and VJP derivative function pointers.
Resolves TF-1146.
This reverts commit 8247525471. While
correct, it has uncovered several issues in existing code bases that
need to be sorted out before we can land it again.
Fixes rdar://problem/57846390.
Prespecialized metadata records must refer to value witness tables that
have correct values for size and stride. In order to do that, a
prespecialized value witness table must emitted and referred to. Here,
a fully specialized value witness table is emitted.
For the moment, the value witness table is fully specialized. Having it
be specialized, though, will likely cause serious code size problems,
since it results in specialized value witness functions being generated.
rdar://problem/58088270
Metadata accessors are dependent on prespecializations of the metadata
of generic, in-module types. Those prespecializations are themselves
dependent on usages of the types in functions. Consequently, the
accessors must be emitted after all the functions are emitted.
When possible, directly reference metadata prespecializations. Doing so
is possible when the type is defined in the same module, because in
those cases the metadata accessor can be modified to ensure that the
prespecialized metadata is canonical.
rdar://problem/56994171
Added worklist of prespecializations awaiting lazy emission to
IRGenModule. Added map from type decl to list of bound types for which
prespecializations will be emitted.
For now, no specializations are emitted.
