This does not remove the llvm dependency for waterbox, just the submodule. The script pulling and checking out llvm kind of conflicts with the submodule, and having it be a submodule is not necessary here anyways.
* Waterbox setup has been revamped to use the latest llvm parts (llvm 16 for compiler_rt/libunwind/libcxx/libcxxabi).
* Clang is now possible to use, and is the preferred compiler (due to superior performance).
* Supported compilers are now clang 14/15/16, and gcc 12.
* Other core updates are mixed in.
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Co-authored-by: Morilli <35152647+Morilli@users.noreply.github.com>
Waterbox supports threads now, but they're not real threads on the host side because that's complicated and can be nondeterministic. Instead, everything is scheduled to share one host thread. This means that scheduling is actually cooperative and certain patterns of spinlocks and other nonsense can fail to work at all, but "regular" code probably will.
With this, add DobieStation PS2 core. This core was selected because it has threads and is otherwise simple to port; easy to build and a good core/frontend separation. It's not a wonderful core however, with low speed (made abysmally lower by our lack of real threads) and low compatibility, so it remains a curiosity for now.
The goal here is to provide an unwind implementation that works. We (probably) don't have a working ldso, so reconfigure libunwind to work without that. To do that, it needs __eh_frame_* variables which it can addressof to find the locations of .eh_frame and .eh_frame_hdr. There is no way I could get gold to add these at all, so switch back to ld and add a custom linkscript. The custom linkscript gives us the opportunity to simplify the savestate memory mapping stuff inside ElfLoader, which should knock a bit of time off of state loads -- those VirtualProtect calls are not cheap. This also removes a potential source of nondeterminism with certain clever out of range pointers.
Any waterbox core that I didn't recompile for this commit will assert now until it is recompiled, because .wbxsyscall is in the wrong palace.
Create an all new waterbox build environment:
WSL2 + Ubuntu 20.04 LTS (Other linuxes may work)
Musl libc with waterbox customizations
LLVM's libclang-rt, libunwind, libcxxabi, libcxx
Static linking to elf files
Compared with the old system, this is easier to set up a dev env for and easier to update in the future. The executables are larger but produce smaller savestates due to static linking. The modern toolchain means advanced library features and language features that sometimes appear in some upstream cores will be reusable.
Morilli