I have exported Rust code to a LLVM-IR (.ll) file and was able to compile and link it manually using both, clang and llc + link.exe. It required to link against a lot of system libraries, Rust libraries and a temporary generated .o file from Rust. I am developing on Windows.

My goal is to run the .ll file using lli. For this I have to tell lli where to find the missing symbols. I couldn’t get the solution from this question to work. I tried -load and -extra-archive + -extra-object. Sadly, there is no output, not even if the sources where found.

For clang it was necessary to add 3 types of sources:

• Rust libraries, e.g.:

  C:Users$USER_NAME.rustuptoolchainsstable-x86_64-pc-windows-msvclibrustlibx86_64-pc-windows-msvcliblibstd-$RANDOM_STRING.rlib
  

• System libraries, e.g.:

  -lws2_32
  

• And a temporary file generated by running cargo rustc --release -- -C save-temps:

  .targetreleasedeps$PROJECT_NAME.$RANDOM_STRING.rcgu.o
  

How do I pass these files to lli correctly?

Context

My goal is to debug the Rust generated LLVM-IR. I found this answer but found this tool to be more promising. However, it requires lli as far as I can tell.

Update

The correct way of linking is before passing the .ll file. This way lli is complaining about wrong paths, etc. Libraries are passed with:

• Rust libraries, e.g.:

  --extra-archive="C:Users$USER_NAME.rustuptoolchainsstable-x86_64-pc-windows-msvclibrustlibx86_64-pc-windows-msvcliblibstd-$RANDOM_STRING.rlib"
  

• And a temporary .o file:

  --extra-object=".targetreleasedeps$PROJECT_NAME.$RANDOM_STRING.rcgu.o"
  

• System libraries .lib would be:

  --extra-archive="C:Program Files (x86)Microsoft Visual Studio2019BuildToolsVCToolsMSVC14.29.30133libx64msvcrt.lib"
  

However, ‘lli’ is still complaining about not found symbols which are in ws2_32.lib and userenv.lib. For some reason it cannot load them from the static library, but clang can when building? Adding windows libraries dynamically fixed it:

--load="C:WindowsSystem32ws2_32.dll"

Yet, there is another error:

LLVM ERROR: Could not resolve external global address: __rust_no_alloc_shim_is_unstable

The allocator shim was supposed to be added with the temporary file. And I assume it is this way when building with clang.