A nix-shell environment for Data.BitCode.Plugin

The purpose of this repository is to facilitate the testing of the ghc plugin that produces bitcode instead of textual ir files.

See also the README at data-bitcode-plugin.

Running via nix

$ nix-shell

should be sufficient to drop into a nix shell with the patched ghc and the data-bitcode-plugin package in the packages database.

Taking the bitcode backend for a spin

Executing ghc with the Data.BitCode.Plugin plugin

[nix-shell]$ ghc examples/HelloWorld.hs -fplugin Data.BitCode.Plugin -fllvm

should produce the examples/HelloWorld binary via the bitcode compilation pass.

Breaking (and fixing) the bitcode backend

Simply add more complex modules to the examples folder, and try to compile them as above. If this does not lead to the expected result, please open a pull request with your module!

Fixing the compilation should often only require to look into src/Data/BitCode/LLVM/Gen.hs in the data-bitcode-plugin package. And comparing it to the current llvm backend in ghc at compiler/llvmGen/LlvmCodeGen/CodeGen.hs.