shayne-fletcher / ocaml-scripts

Set of scripts to help building OCaml projects using buck2.

ocaml-scripts

Experimental scripts to build a BUCK/TARGETS file from an opam switch. Forwords: this is Python, for now, because we hope to reuse most of this experiment to improve supercaml in tp2, which requires python.

Ultimately we want to reuse these to setup ocaml projects at Meta, and to support buck2/ocaml for OSS.

Disclaimer: all scripts are a work in progress, please update them to fit your needs and report your changes back.

All scripts display a help screen showing all possible arguments by adding -h or --help to their command line.

BUCK_PATH usually is something like ./third-party/BUCK or ./third-party/ocaml/BUCK in Buck's root directory.

dromedary.py

You can use dromedary.py to generate an opam switch or use an existing one.

Running python3 dromedary.py -o BUCK_PATH JSON_CONFIG will use the JSON configuration file JSON_CONFIG to generate a new Opam switch and install the configured packages. The Buck 2 file BUCK_PATH is generated from the packages of the generated switch.

Running python3 dromedary.py -s SWITCH_NAME -o BUCK_PATH will parse the Opam switch SWITCH_NAME for package information and create a BUCK file at BUCK_PATH. If no -s SWITCH_NAME is given, the currently active one is used. To exclude packages from BUCK_PATH, use -e with a space separated list of package names: python3 dromedary.py -s SWITCH_NAME -o BUCK_PATH -e ocaml_lsp_server ocamlformat does not include the packages ocaml_lsp_server and ocamlformat.

JSON configuration:

See file ./dromedary_example.json.

{
    "name": "./third-party",
    "compiler": "ocaml-base-compiler",
    "packages": [
        "menhirLib",
        "sedlex=3.2",
        "alcotest>=1.7.0"
    ]
}

• name - Either the path to the directory to generate the Opam switch in or the global name of the switch. The path is relative to the directory of the JSON file. If this is missing, "./" is used.
• compiler - The compiler to use for the switch. If this is missing, "ocaml-variants" is used.
• packages - An array of Opam packages to install, may contain version numbers, each string is passed verbatim to opam install. Must be present.

Note: dromedary.py internally uses the scripts meta2json.py and rules.py, so no need to call them separately.

meta2json.py

Running python3 meta2json.py -o JSON_PATH or python3 dromedary.py -j JSON_PATH -o BUCK_PATH will dump all the collected information for the current opam switch in the env into a .json file JSON_PATH (data.json is provided as an example). To exclude packages from the generated file(s), use -e with a space separated list of package names: python3 meta2json.py -o JSON_PATH -e ocaml_lsp_server ocamlformat does not include the packages ocaml_lsp_server and ocamlformat.

rules.py

Running python3 rules.py -i JSON_PATH -s SWITCH_ROOT_PATH -o BUCK_PATH will read the previously generated json file JSON_PATH and create a BUCK file BUCK_PATH aimed at OSS releases.

These scripts are provided for internal experimentation only and should not be used until we settle on a proper workflow.

Note: rules.py and dromedary.py might generate warnings like the following ones, which are expected: these are native libraries name that we try to locate in the opam switch (and where we fail, because they are system wide libraries, not opam ones).

WARNING:root:Could not find file: /data/users/vsiles/opam/4.14.0+flambda/lib/ctypes/libintegers_stubs.a
WARNING:root:Could not find file: /data/users/vsiles/opam/4.14.0+flambda/lib/mtime/clock/os/librt.a
...

Join the ocaml-scripts community

See the CONTRIBUTING file for how to help out.

License

ocaml-scripts is MIT licensed, as found in the LICENSE file.