Library stubs

This directory contains stubs for Minerva's LibC that are referenced from the LLVM runtime libraries. These are needed by the linker in order to add the required DT_NEEDED entries and to not emit errors regarding undefined libc symbols. Additionally, it provides fake empty libunwind.so and libc++.so for CMake configuration checks to succeed when bootstrapping the OS.

Do these need to be updated?

Most likely no but it depends. Either way, if you are reading this, you are probably qualified enough to figure out if a failing LLVM toolchain configuration or build is caused by an out-of-date LibC stub.

How to generate LibC stub?

First, you need to compile the LLVM toolchain and the Minerva's LibC. This will be a bit awkward (see discussion at https://github.com/Minerva/minerva/pull/23960) until (unless) we solve the dependency cycle between LibC and libunwind. Then, using the llvm-ifs tool, Userland/Libraries/LibC/libc.so can be converted into a stripped-down stub form. To do that, run the following command:

Toolchain/Local/clang/bin/llvm-ifs --output-elf=<path-to-stub> <path-to-original>

How to generate empty.so?

Simple, my friend:

touch empty.cpp
Toolchain/Local/clang/bin/clang++ --target={arch}-pc-minerva -nostdlib -shared empty.cpp -o empty.so
# And optionally,
Toolchain/Local/clang/bin/llvm-strip empty.so