llvm-project-redist

Repackages llvm-project source releases with the Bazel build overlay pre-applied and publishes them to the Bazel Central Registry as the llvm-project module. Bazel is not tested as part of the LLVM release process, so patches are sometimes required to fix build issues after a release is cut. This repo manages those patches and the automation that gets working archives into the BCR.

This is not a fork of llvm-project. Patches should be reflected upstream and not deviate from the desires and direction of the LLVM org.

Discussion and issues

For issues related to LLVM itself, please use the upstream llvm-project issue tracker or LLVM Discourse forums. This repo's issue tracker is only for problems specific to the BCR packaging and release automation.

How it works

When LLVM cuts a release, a GitHub Actions workflow detects it, downloads the upstream source tarball, verifies its GPG signature, applies the Bazel overlay and any version-specific patches, and repackages the result as deterministic .tar.xz and .tar.zst archives. The archives are published as a GitHub release with provenance attestations and SRI integrity files, then automatically submitted to the BCR.

Version scheme

Release type	Version	Tag	Example
Base release	X.Y.Z	llvmorg-X.Y.Z	20.1.0
Patched release	X.Y.Z.bcr.N	llvmorg-X.Y.Z.bcr.N	20.1.0.bcr.1

Base releases match upstream LLVM versions. Patched releases (.bcr.N) incorporate fixes for Bazel compatibility issues discovered after the upstream release.

Repository structure

versions/
  17.0.3/
    version.txt                              # release version (e.g. 17.0.3.bcr.5)
    presubmit.yml                            # BCR presubmit test config
    patches/
      001_fix_build.patch                    # git-formatted patches, applied in order
.bcr/
  presubmit.yml                              # template for new versions
  source.template.json                       # BCR source.json template
  metadata.template.json                     # BCR metadata.json template

The upstream tarball, its GPG signature, and the LLVM release signing key are downloaded from official sources at build time and never committed.

Local development

# Set up local presubmit testing (mirrors BCR workflow)
bazel run //tools:setup_presubmit -- 17.0.3

# Build a release archive locally
bazel run //tools:build -- --llvm-version 17.0.3

# Validate version directories
bazel run //tools:validate_patches -- versions

# Regenerate Python dependency lockfile
bazel run //tools:requirements.update

# Run tests
bazel test //tools/...

# Run pre-commit hooks
pre-commit run --all-files

Contributing

See CONTRIBUTING.md.

Maintenance

See MAINTENANCE.md for workflow descriptions and failure recovery procedures for maintainers of llvm-project-redist.