update-upstream.yml

name: Update from Upstream

on:
  workflow_dispatch:
    inputs:
      to_ref:
        description: "Upstream version tag to import up to, e.g., 1.9.0"
        required: true
        type: string

permissions:
  contents: write
  pull-requests: write

jobs:
  update:
    name: Import Upstream Commits
    runs-on: ubuntu-latest
    steps:
      - name: Checkout
        uses: actions/checkout@v6
        with:
          fetch-depth: 0
          token: ${{ secrets.GITHUB_TOKEN }}

      - name: Configure git
        run: |
          git config user.name "github-actions[bot]"
          git config user.email "41898282+github-actions[bot]@users.noreply.github.com"

      - name: Import upstream commits
        id: import
        run: |
          # Auto-detect from_ref: find latest *-bsd tag, strip suffix to get upstream ref
          from=$(git tag -l '*-bsd' --sort=-v:refname | head -1 | sed 's/-bsd$//')
          if [ -z "$from" ]; then
            echo "No *-bsd tags found. Tag the initial import first (e.g., git tag 1.8.11-bsd)." >&2
            exit 1
          fi
          target="${{ inputs.to_ref }}"

          branch="update-upstream-${target}"
          git branch -D "$branch" 2>/dev/null || true
          git push origin --delete "$branch" 2>/dev/null || true
          git checkout -b "$branch"

          scripts/import-upstream.sh "$from" "$target" 2>&1 | tee import-log.txt

          imported=$(grep -oP 'Imported: \K[0-9]+' import-log.txt || echo "0")
          echo "imported=$imported" >> "$GITHUB_OUTPUT"
          echo "branch=$branch" >> "$GITHUB_OUTPUT"
          echo "from=$from" >> "$GITHUB_OUTPUT"

      - name: Create or update PR
        if: steps.import.outputs.imported != '0'
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          TARGET: ${{ inputs.to_ref }}
          BRANCH: ${{ steps.import.outputs.branch }}
          FROM: ${{ steps.import.outputs.from }}
        run: |
          git push origin "$BRANCH"

          # Generate PR body
          cat > pr-body.md <<EOF
          ## Upstream Update: picolibc ${TARGET}

          **Upstream compare**: [${FROM:0:12}...${TARGET}](https://github.com/picolibc/picolibc/compare/${FROM:0:12}...${TARGET})

          ### Imported commits
          $(git log --oneline main..HEAD | head -50)

          ### Checklist
          - [ ] Review imported commits
          - [ ] Verify license scan passes
          - [ ] Update version table in README.md
          - [ ] Merge with **rebase** to preserve commit history
          - [ ] After merge, tag will be created automatically
          EOF

          existing_pr=$(gh pr list --head "$BRANCH" --json number --jq '.[0].number' 2>/dev/null || true)
          if [[ -n "$existing_pr" ]]; then
            gh pr edit "$existing_pr" --title "Update from upstream picolibc ${TARGET}" --body-file pr-body.md
          else
            gh pr create --base main --head "$BRANCH" --title "Update from upstream picolibc ${TARGET}" --body-file pr-body.md
          fi