This changes how host trampolines for guest functions are created. Instead
of doing this purely on the guest-side, it's either the host-side that
creates them in a single step *or* a cooperative two-step initialization
process must be used. In the latter, trampolines are allocated and partially
initialized on the guest and must be finalized on the host before use.
This will help compiling on older distros which are shipping older
Vulkan-Headers.
We need to catch newer Vulkan features earlier than what distros ship
since it is highly common that users will update their drivers through
means that make their drivers be newer.
For example to build on Ubuntu 20.04 we will support symbols much newer
than what that verison of the distro supports.
We could wrap all uses of newer features behind `#ifdef` checks, or
include the newest version of the loader that FEX itself supports.
The submodule is much cleaner and resolves the issue of drivers
supporting newer vulkan versions than libvulkan-dev.
Again super common with Nvidia blob users, kisak-ppa users, or people
updating mesa directly to be on the bleeding edge.
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).
This could also prove useful for guest libraries, however the implicit
dependency of libEGL on libGL (via glXGetProcAddress) cannot be resolved
easily with the current build setup.
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
Ryan Houdek