These are the minimal changes to make the reverse interop header compile
when embedded Swift is used. Previously, the _SwiftStdlibCxxOverlay.h
and the generated interop header disagreed on the mangling of a symbol.
This is not sufficient yet to use the embedded Swift standard library from
reverse interop, there are some missing symbols while linking. But this
PR enables doing reverse interop without using the stdlib types like
swift::String in C++. Follow-up PRs will fix the rest of the issues.
rdar://154740225
Extend the previous commit’s support for functions that return Never to also properly generate code for *throwing* Never functions. This is a little subtle because:
• At the SWIFT_CALL level, throwing Never functions are *not* noreturn
• At the thunk level, throwing Never functions are noreturn *only* if you’re using exceptions; if you’re using swift::Expected, they should throw
• In either case, the compiler cannot statically prove that thunks are noreturn except on the error path, so we need to add an abort() call on the success path
This allows easier use and more wider API exposure from the Swift stdlib
In the future, all functions and method should incorporate argument labels, but it's not yet clear how
This macro applies always_inline in addition to inline. It also applies artificial, which lets debugger know that this is an artificial function. The used attribute is added in debug builds to ensure that the symbol is emitted in the binary so that LLDB can invoke it.
This is done by exposing nested Index and UTF8View type in String. Nested types aren't
supported yet, so we need to employ a number of hacks to emit them.
