Whole Kernel Bitcode

Existing tools such as wllvm gllvm don't seem to work without errors for the linux kernel.

This is not an alternative to those tools. They work with not just the kernel but any program. This is a tool specifically for the linux kernel. And hasn't been tested on other programs.

How it works

1. Compiles the kernel with llvm/clang.
2. Using the compile_commands.json generated by clang, it compiles each source file into a bitcode file.
3. Using the .buit-in.a.cmd files generated by the kernel build system, it hirarchically links the bitcode files into a single bitcode file.

Ceveats:

Certain source files in the kernel are assembly files. These files are not linked into the final bitcode file.

Notes

This has been tested on

• linux - 5.10.0
• defconfig
• llvm 10.0.1