llir3

README

This is the Go code from Step 3 of:

https://github.com/llir/llvm/issues/86#issuecomment-498357924

Being worked on to add enough DWARF metadata, so that -g on the clang command line works and embeds decent ".debug_*" sections.

When main.go is run, it will generate an LLVM IR file to stdout, so you'll probably want to redirect it to a file:

$ go run main.go > foo.ll

This .ll file can be compiled to a Linux executable using clang:

$ clang --target=x86_64-pc-linux-gnu -g -Wno-override-module -o foo foo.ll

To view the DWARF debugging sections, use llvm-dwarfdump:

$ llvm-dwarfdump -color foo | more

The goal is to add DWARF to Wasm binaries, so a working debugger for Wasm can be created.

A working command to generate Wasm from the .ll is:

$ clang --compile --target=wasm32-unknown-unknown-wasm -g -Wno-override-module -o foo.wasm foo.ll

Note that the --compile option to clang is required. Without it, clang will attempt to link the Wasm for the current system, and fail:

$ clang --target=wasm32-unknown-unknown-wasm -g -Wno-override-module -o foo.wasm foo.ll
wasm-ld: error: unknown file type: /lib/crt1.o
wasm-ld: error: unable to find library -lc
wasm-ld: error: cannot open /opt/llvm8-wasm/lib/clang/8.0.1/lib/libclang_rt.builtins-wasm32.a: No such file or directory
clang-8: error: lld command failed with exit code 1 (use -v to see invocation)