Host thunk libraries are always built as part of the main project now.
Guest thunk libraries are still cross-compiled in a CMake ExternalProject,
but *additionally* there are CMake targets in the main project to make
sure IDE engines can properly handle guest source files.
Notably, xcb_take_socket uses the callback_guest annotation, since the
given callback is never called on the host (instead it's manually forwarded
back to a helper guest thread for calling).
Function pointer arguments given to the guest thunk library aren't
callable on the host, so they need special handling on a case-by-case
basis. Similar problems arise when the guest-side tries to consume a
pointer returned from a native host library. To automate some common
scenarios, this change adds two new annotations:
"callback_guest" indicates the callback parameter is never called on the
host and hence can be marshalled like any other argument. Accidental host
calls to the function pointer are prevented by wrapping it in an opaque
type alias.
"returns_guest_pointer" indicates that the host function returns a pointer
usable in the guest context. This applies e.g. to functions that derive
the returned pointer from input guest pointer arguments.
Keeping this in the commit history to go back to later.
While these are required for static-pie builds to work, with the glibc
bug we can't use those yet.
Disable for now since it is is unnecessary.
Instead of searching inside the thunk folder for Guest and Host files
with a library name attached to it, also search for ones That are just
named `Host.cpp` and `Guest.cpp`.
Makes quickly pounding out a bunch of thunks significantly less tedious.
This is necessary for building FEX packages that contain some initial thunk libs.
Gives an initial foothold for a default location for the host and guest thunk folders
This interface is for native host code to be able to call back in to JIT
to execute guest code.
This is mainly for thunks but could be used for other purposes.
This can cross a couple ABI boundaries so one must be careful when
calling in to this
