README.md

OCaml rules for Bazel

Rules

• ocaml_native_binary
• ocaml_bytecode_binary
• ocaml_interface

Overview

Build OCaml with Bazel. Very experimental.

Setup

Add the following to your WORKSPACE file.

git_repository(
    name = "io_bazel_rules_ocaml",
    remote = "https://github.com/jin/rules_ocaml.git",
    commit = "7a0a6e5226af5f09eb6e3379b901d8f2ffdb8bbf",
)

load("@io_bazel_rules_ocaml//ocaml:repo.bzl", "ocaml_repositories")
ocaml_repositories(
    opam_packages = {
        # Put your OPAM dependencies here
        "lwt": "3.1.0",
        "yojson": "1.4.0",
    },
)

and this to your BUILD files.

load("@io_bazel_rules_ocaml//ocaml:ocaml.bzl", "ocaml_native_binary", "ocaml_bytecode_binary", "ocaml_interface")

ocaml_repositories() will download and compile the OCaml toolchain, including ocamlbuild, ocamlfind and OPAM itself, as the official source doesn't release binaries directly and requires the use of OPAM for installations.

The initial load time of toolchain compilation will take a few minutes and will not happen again for the same project.

Rules

ocaml_native_binary/ocaml_bytecode_binary

Generates a native binary using ocamlopt or bytecode binary using ocamlc.

ocaml_native_library(name, srcs, src_root, opam_packages)
ocaml_bytecode_library(name, srcs, src_root, opam_packages)

Example

ocaml_native_binary(
    name = "hello_world",
    srcs = glob(["examples/*.ml"]),
    src_root = "examples/hello_world.ml",
    opam_packages = ["yojson", "lwt"],
)

ocaml_bytecode_binary(
    name = "other_binary",
    srcs = [
      "examples/foo.ml",
      "examples/bar.ml",
      "examples/entry.ml",
    ],
    src_root = "examples/entry.ml",
    opam_packages = ["pkg_foo", "pkg_bar"],
)

Attributes
name	Name, required A unique name for this target
srcs	List of labels, required List of OCaml .ml source files used to build the library
src_root	Label, optional The OCaml .ml source file used for the binary's entry point. Defaults to main.ml if not specified.
opam_packages	List of strings, optional The name of the OPAM package dependencies required by this binary. The packages (and their versions) must already be defined in your WORKSPACE file's ocaml_repositories().

ocaml_interface

Generates a .mli file of the source file.

ocaml_interface(name, src)

Attributes
name	Name, required A unique name for this target
src	Label The OCaml .ml source file used for generating the interface file

Example

ocaml_interface(
    name = "hello_world_interface",
    src = "examples/hello_world.ml",
)

Projects using rules_ocaml

• https://github.com/jin/scheme.ml