Correct the IRGen for the standard library. The thinko here assumed that the else case would be evaluated for the standard library build. We ended up incorrectly handling the well-known VWTs from the runtime when building the standard library.
This adjusts the runtime function declaration handling to track the
owning module for the well known functions. This allows us to ensure
that we are able to properly identify if the symbol should be imported
or not when building the shared libraries. This will require a
subsequent tweak to allow for checking for static library linkage to
ensure that we do not mark the symbol as DLLImport when doing static
linking.
Put AvailabilityRange into its own header with very few dependencies so that it
can be included freely in other headers that need to use it as a complete type.
NFC.
Remove `IRGenModule::useDllStorage()` as there is a standalone version
that is available and the necessary information is public from the
`IRGenModule` type. Additionally, avoid the wrapped `isStandardLibrary`
preferring to use the same method off of the public accessors. This
works towards removing some of the standard library special casing so
that it is possible to support both static and dynamic standard
libraries on Windows.
`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.
As per #65930, the Clang importer's Clang instance may be configured with a different (higher) OS version than the compilation target itself in order to be able to load pre-compiled Clang modules that are aligned with the broader SDK, and match the SDK deployment target against which Swift modules are also built. Code-generation, however, must use the actual compilation target triple. This matches how Swift itself loads Swift module dependencies as well: dependency '.swiftinterface' files are type-checked against the availability epoch and code-generated against the actual compilation triple.
Resolves rdar://113712186
Motivated by need for protocol-based dynamic dispatch, which hasn't been possible in Embedded Swift due to a full ban on existentials. This lifts that restriction but only for class-bound existentials: Class-bound existentials are already (even in desktop Swift) much more lightweight than full existentials, as they don't need type metadata, their containers are typically 2 words only (reference + wtable pointer), don't incur copies (only retains+releases).
Included in this PR:
[x] Non-generic class-bound existentials, executable tests for those.
[x] Extension methods on protocols and using those from a class-bound existential.
[x] RuntimeEffects now differentiate between Existential and ExistentialClassBound.
[x] PerformanceDiagnostics don't flag ExistentialClassBound in Embedded Swift.
[x] WTables are generated in IRGen when needed.
Left for follow-up PRs:
[ ] Generic classes support
The generality of the `AvailabilityContext` name made it seem like it
encapsulates more than it does. Really it just augments `VersionRange` with
additional set algebra operations that are useful for availability
computations. The `AvailabilityContext` name should be reserved for something
pulls together more than just a single version.
This makes sure that Swift respects `-Xcc -stdlib=libc++` flags.
Clang already has existing logic to discover the system-wide libc++ installation on Linux. We rely on that logic here.
Importing a Swift module that was built with a different C++ stdlib is not supported and emits an error.
The Cxx module can be imported when compiling with any C++ stdlib. The synthesized conformances, e.g. to CxxRandomAccessCollection also work. However, CxxStdlib currently cannot be imported when compiling with libc++, since on Linux it refers to symbols from libstdc++ which have different mangled names in libc++.
rdar://118357548 / https://github.com/swiftlang/swift/issues/69825
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)
In embedded swift features are available independent of deployment and runtime targets because the runtime library is always statically linked to the program.
Typed pointers are slowly being removed. There's a lot more cleanup to
do here, since really all `IRGenModule::.*PtrTy` should just be `PtrTy`,
but this at least gets us compiling for now.
