nccl rules for Bazel

This repository contains Starlark implementation of nccl rules in Bazel.

These rules provide some macros and rules that make it easier to build nccl with Bazel.

Getting Started

Traditional WORKSPACE approach

Add the following to your WORKSPACE file and replace the placeholders with actual values.

load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
http_archive(
    name = "rules_nccl",
    sha256 = "{sha256_to_replace}",
    strip_prefix = "rules_nccl-{git_commit_hash}",
    urls = ["https://.../{git_commit_hash}.tar.gz"],
)
load("@rules_nccl//nccl:repositories.bzl", "rules_nccl_dependencies")
rules_nccl_dependencies()

Bzlmod

Add the following to your MODULE.bazel file and replace the placeholders with actual values.

bazel_dep(name = "rules_nccl", version = "0.0.1")

# pick a specific version (this is optional an can be skipped)
archive_override(
    module_name = "rules_nccl",
    integrity = "{SRI value}",  # see https://developer.mozilla.org/en-US/docs/Web/Security/Subresource_Integrity
    urls = "https://.../{git_commit_hash}.tar.gz",
    strip_prefix = "rules_nccl-{git_commit_hash}",
)

nccl = use_extension("@rules_nccl//nccl:extensions.bzl", "toolchain")
nccl.local_toolchain(
    name = "local_nccl",
    nccl_path = "",
)
use_repo(nccl, "local_nccl")

Available dependencies

• nccl_runtime: Can be used to compile and link to NCCL shared library.
• nccl_runtime_static: Can be used to compile and link to NCCL static library.
• @rules_nccl//nccl:runtime: Default is same as nccl_runtime.

Tests

bazel test //nccl/tests:all