name: bootstrap

# The headline guarantee of a self-hosted, C-free toolchain: assembled from the
# checked-in IR seed with clang alone, the compiler recompiles its own source
# and reproduces that seed **byte-for-byte**. A regression here (a compiler
# change that was never reseeded) is otherwise invisible until someone runs it
# locally. This job fails the moment out.ll != seed.ll.
on:
  push:
    branches: [main]
  pull_request:
  workflow_dispatch: {}

jobs:
  cfree-fixpoint:
    runs-on: docker
    container: node:20-bookworm
    steps:
      - name: Install clang-16
        run: |
          set -eu
          export DEBIAN_FRONTEND=noninteractive
          apt-get update -qq
          apt-get install -y -qq --no-install-recommends clang-16 git ca-certificates
          clang-16 --version | head -1

      - name: Check out the triggering commit
        env:
          # the repository that triggered the run, so a fork or a mirror tests itself
          REPO_URL: ${{ github.server_url }}/${{ github.repository }}.git
        run: |
          set -eu
          git config --global --add safe.directory '*'
          git clone "$REPO_URL" .
          git checkout "${GITHUB_SHA}" 2>/dev/null || git checkout "${GITHUB_REF_NAME:-main}"
          git log --oneline -1
          # See ci.yml for why the Linux build injects the stdio shim via LUDIC_CC.
          echo "LUDIC_CC=clang-16 $(pwd)/tools/ci/linux_stdio_shim.ll" >> "$GITHUB_ENV"
          echo "LUDIC_HOME=$(pwd)" >> "$GITHUB_ENV"

      - name: Bootstrap x from the seed
        run: |
          set -eu
          mkdir -p bin
          clang-16 tools/ci/linux_stdio_shim.ll selfhost/ludicc.seed.ll -o bin/ludicc
          bin/ludicc tools/ludic-cli/main.ludic -o bin/ludic

      - name: Rebuild the compiler from the seed and assert byte-identity
        # `ludic dev bootstrap-cfree` assembles the seed with clang, has that seed
        # compiler recompile selfhost.ludic to out.ll, and `cmp`s out.ll against
        # the checked-in seed. It returns non-zero if they differ — i.e. if the
        # seed is stale relative to the compiler source.
        run: bin/ludic dev bootstrap-cfree