LLVM tutorial with Dune (Part 2)

Hi everyone, I just made an updated version of the OCaml LLVM since the posted one is pretty out of date. Check it out here: https://github.com/adamrk/llvm-ocaml-tutorial. The main changes are:

  • switch build system to dune from ocamlbuild
  • switch lexing and parsing to use ocamllex/menhir instead of camlp4
  • update to newer LLVM API (version 6.0.0)

There are also a couple outstanding issues that I can’t figure out, so if you have any ideas how to fix these it’d be really helpful:

  • Menhir is generated files which cause warnings during compilation:
ocamlc lib/parser__mock.mli.inferred
  File "parser__mock.ml.mock", line 388, characters 9-18:
  Warning 3: deprecated: Not_found
ocamlopt lib/.kaleidoscope_lib.objs/kaleidoscope_lib__Parser.{cmx,o}
  File "parser.ml", line 161, characters 45-612:
  Warning 9: the following labels are not bound in this record pattern: state

Are there any ways to prevent Menhir from causing these warnings? I’m currently handling it by suppressing the warnings with

  (flags (:standard -warn-error -3-9))))

in the dune file. Alternatively, is there a way to suppress the warnings only for these specific files?

  • The cstubs are currently printing to stderr because when I set them to print to stdout, those calls don’t occur until the program exists. Any ideas on why that happens and if there is a better fix?
  • I’m currently linking the cstubs dynamically which is annoying. Does anyone know if there’s a way to statically link them in?

Edit: actually it appears that the Warning 9 problem was fixed in the latest version of Menhir (20181113). Not_found is actually only deprecated in Base/Core so I got rid of that error by not opening Core at the toplevel. I’m still curious about if there’s an easy way to suppress warnings only for specific files though.


You can locally disable the warnings with [@ocaml.warning “-9”] or [@@ocaml.warning “-9”]. If you use a version of ocaml prior to 4.06, you may be better off by wrapping the module with

[@@@ocaml.warning “-9”]
[@@@ocaml.warning “+9”]
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