Rewrite the handling for the `CxxStdlib` implicit linking to use a
slightly more functional style for filtering. Additionally, add Windows
to the list providing the overlay. The Windows linking scenario is a
slightly more complicated as the library names differ between static and
dynamic variants to disambiguate between import libraries and static
libraries. Take this into account when embedding the library name so
that the linker can find the appropriate content.
Also, make some related changes, like updating a path in the Android doc, making sure the
`unknown` vendor is always used, and using `CPU` instead of `CODEGENERATOR`.
Before this patch we tried to do lookup in the _ObjC module for the retain/release functions. Now we use the clang module that the reference type lives in.
The logic is here for this in the importer, which means the module interface tests make it appear that the behavior is correct, but lazy member lookup still finds the constructors, so this patch fixes that part.
- #58975 switched many tests from XFAIL on linux to linux-gnu, so seven
fail on the Android CI and two natively. They are now explicitly excluded.
- #39605 added several C++ Interop tests, 11 of which fail on the Android CI,
so disable them for now.
- #42478 removed the @noescape attribute for the non-Android
SIL/clang-function-types tests, so I remove it for Android too.
- My pull #40779 moved the Swift pointer tags to the second byte, so
SILOptimizer/concat_string_literals.64 will need to be updated for that,
disabled it for now.
- Compiler-rt moved the directory in which it places those libraries for
Android, llvm/llvm-project@a68ccba, so lit.cfg is updated for that.
The main point of this change is to make sure that a shared function always has a body: both, in the optimizer pipeline and in the swiftmodule file.
This is important because the compiler always needs to emit code for a shared function. Shared functions cannot be referenced from outside the module.
In several corner cases we missed to maintain this invariant which resulted in unresolved-symbol linker errors.
As side-effect of this change we can drop the shared_external SIL linkage and the IsSerializable flag, which simplifies the serialization and linkage concept.
There are three major changes here:
1. The addition of "SILFunctionTypeRepresentation::CXXMethod".
2. C++ methods are imported with their members *last*. Then the arguments are switched when emitting the IR for an application of the function.
3. Clang decls are now marked as foreign witnesses.
These are all steps towards being able to have C++ protocol conformance.
