name: LLVM distribution

# Builds the LLVM that the Linux release helpers link
# (native/llvm-codegen/llvm-dist.mjs): LLVM from its release sources with
# ThinLTO and native/llvm-codegen/llvm.profdata.gz, for each Linux
# architecture. Each job builds a helper against it and one against LLVM's
# release archive, requires the two to give identical objects on this
# checkout's helper inputs (scripts/check-llvm-dist.mjs), prints both
# helpers' times, and attaches the archive to the LLVM_DIST_TAG release.
# The arm64 build uses the profile collected on x64; its job log reports how
# many functions the profile no longer matches. Run it after a profile refresh
# or an LLVM version change, with a new LLVM_DIST_TAG.
on:
  workflow_dispatch:

permissions:
  contents: read

concurrency: ${{ github.workflow }}

jobs:
  build:
    name: Build LLVM (${{ matrix.arch }})
    if: github.repository == 'vercel-labs/scriptc'
    strategy:
      fail-fast: false
      matrix:
        include:
          - arch: x64
            runner: ubuntu-24.04
            llvm_asset: LLVM-22.1.8-Linux-X64
          - arch: arm64
            runner: ubuntu-24.04-arm
            llvm_asset: LLVM-22.1.8-Linux-ARM64
    runs-on: ${{ matrix.runner }}
    # About an hour for LLVM on 4 cores, and 5 minutes for each helper link.
    timeout-minutes: 240
    permissions:
      contents: write
    steps:
      - uses: actions/checkout@v4
      - uses: pnpm/action-setup@v4
        with:
          version: 11.1.3
      - uses: actions/setup-node@v4
        with:
          node-version: "24"
          cache: pnpm
      - name: Install LLVM's release archive and sources
        run: |
          sudo apt-get update
          sudo apt-get install --yes ninja-build zlib1g-dev libzstd-dev
          base=https://github.com/llvm/llvm-project/releases/download/llvmorg-22.1.8
          curl -fL --retry 3 -o "$RUNNER_TEMP/llvm.tar.xz" "$base/${{ matrix.llvm_asset }}.tar.xz"
          tar -xJf "$RUNNER_TEMP/llvm.tar.xz" -C "$RUNNER_TEMP"
          mv "$RUNNER_TEMP/${{ matrix.llvm_asset }}" "$RUNNER_TEMP/llvm-22.1.8"
          curl -fL --retry 3 -o "$RUNNER_TEMP/llvm-src.tar.xz" "$base/llvm-project-22.1.8.src.tar.xz"
          tar -xJf "$RUNNER_TEMP/llvm-src.tar.xz" -C "$RUNNER_TEMP"
          rm "$RUNNER_TEMP/llvm.tar.xz" "$RUNNER_TEMP/llvm-src.tar.xz"
          echo "$RUNNER_TEMP/llvm-22.1.8/bin" >> "$GITHUB_PATH"
      - run: pnpm install --frozen-lockfile
      - run: pnpm --filter @scriptc/compiler --filter scriptc build
      - name: Build the distribution
        run: >-
          node scripts/build-llvm-dist.mjs --source "$RUNNER_TEMP/llvm-project-22.1.8.src"
          --prefix "$RUNNER_TEMP/dist/scriptc-llvm-22.1.8-linux-${{ matrix.arch }}"
          --archive "$RUNNER_TEMP/scriptc-llvm-22.1.8-linux-${{ matrix.arch }}.tar.xz"
          --work "$RUNNER_TEMP/llvm-dist-work"
      - name: Build a helper against each LLVM
        env:
          HELPER: llvm-linux-${{ matrix.arch }}-gnu
        run: |
          LLVM_DIR="$RUNNER_TEMP/llvm-22.1.8/lib/cmake/llvm" pnpm --filter "@scriptc/$HELPER" build:native
          cp "packages/$HELPER/bin/scriptc-llvm-codegen" "$RUNNER_TEMP/helper-release-archive"
          LLVM_DIR="$RUNNER_TEMP/dist/scriptc-llvm-22.1.8-linux-${{ matrix.arch }}/lib/cmake/llvm" \
            SCRIPTC_LLVM_THINLTO=1 pnpm --filter "@scriptc/$HELPER" build:native
          cp "packages/$HELPER/bin/scriptc-llvm-codegen" "$RUNNER_TEMP/helper-profiled"
      - name: Compare the helpers
        run: >-
          node scripts/check-llvm-dist.mjs --baseline "$RUNNER_TEMP/helper-release-archive"
          --candidate "$RUNNER_TEMP/helper-profiled" --rounds 3 --work "$RUNNER_TEMP/llvm-check"
      - name: Attach the archive to the release
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          ARCHIVE: ${{ runner.temp }}/scriptc-llvm-22.1.8-linux-${{ matrix.arch }}.tar.xz
        run: |
          tag=$(node --input-type=module -e "import { LLVM_DIST_TAG } from './native/llvm-codegen/llvm-dist.mjs'; console.log(LLVM_DIST_TAG)")
          # Both architectures' jobs create the release if it is missing.
          gh release view "$tag" > /dev/null 2>&1 ||
            gh release create "$tag" --target "$GITHUB_SHA" --title "$tag" --latest=false \
              --notes "LLVM 22.1.8 built with ThinLTO and the helper profile, for the Linux LLVM helpers (scripts/build-llvm-dist.mjs)." ||
            gh release view "$tag" > /dev/null
          gh release upload "$tag" "$ARCHIVE" "$ARCHIVE.sha256" --clobber