=== LLDB Improvement on FreeBSD

Links: +
link:https://github.com/llvm/llvm-project/issues/180061[LLVM Meta Issue] URL: link:https://github.com/llvm/llvm-project/issues/180061[] +

Contact: Minsoo Choo <minsoochoo0122@proton.me>

Due to the licensing issue with GDB (GPLv3), FreeBSD has adopted LLVM, including LLDB, in its base system since FreeBSD 10.0.
However, most kernel developers still rely on KGDB, a patched version of a recent GDB, to debug the kernel.
This is partly a matter of personal preference (some find GDB's command syntax more comfortable), but there are also practical reasons: LLDB lacks several features that KGDB provides (see below for details) and has insufficient support even in the base system.
My work aims to achieve feature parity with KGDB by the end of April.

The improvements I have made so far are listed in the link above.
Note that small bug fixes are not included in that list.

The following are not supported: i386, arm, powerpc32, powerpc64be, and mips*.
FreeBSD 13 and earlier are also unsupported.
The targeted LLVM version is 23, although this work may be backported to FreeBSD's in-tree LLVM and MFCed to stable/14 and stable/15 after mailto:dim@FreeBSD.org[Dimitry Andric] finishes his LLVM 21 MFV.

I started this work in late January, and it is projected to be complete by April.
Beyond feature parity, there are further possible improvements, such as minidump2elf support and adding UUIDs to kernel and core dump ELF headers.

The biggest blocker for this project is a lack of reviewers knowledgeable in both FreeBSD internals and KGDB internals.
If you have time, please provide feedback on my pull requests.
Testers on non-x86 and non-arm64 machines would also be very welcome.
If you find any issues, please file a bug and ping me on llvm/llvm-project.

Sponsor: The FreeBSD Foundation