build.yml

name: Build
on:
  - push
  - pull_request

jobs:
  natives-linux:
    name: Linux (x86_64) native library compilation
    runs-on: ubuntu-latest
    container:
      image: ubuntu:18.04
      env:
        GCC: gcc-8

    defaults:
      run:
        working-directory: src/main/c

    steps:
      - name: Checkout the target branch
        uses: actions/checkout@v3
      - name: Setup Java
        uses: actions/setup-java@v3
        with:
          distribution: temurin
          java-version: 8
          # Don't need the dependency cache here (or in any of the other native
          # library compilation steps), because we're not invoking the Java
          # compiler in this step. We only need the JDK for its headers.
      - name: Install build prerequisites
        run: |
          apt-get update
          apt-get --assume-yes install make $GCC

      - name: Build the Linux native libraries (x86_64 only)
        run: |
          make clean-linux
          make linux64

      # The names of the artifacts containing native libraries correspond
      # exactly to the directories inside `src/main/c/resources/native`. That
      # way, the Java build job can pull down all artifacts and unpack them
      # into that directory to overwrite the versions in-repo. This is sadly
      # necessary because the actions/download-artifact@v3 action flattens
      # paths inside artifacts. If it retained full relative paths, we could
      # put Linux and Windows natives inside the same artifact, and we could be
      # flexible with the artifact names. But it doesn't, so we can't, and we
      # can't.
      - name: Upload Linux native libraries
        uses: actions/upload-artifact@v3
        with:
          name: linux
          path: src/main/c/resources/native/linux

  java:
    name: Java compilation
    runs-on: ubuntu-latest

    needs:
      - natives-linux

    steps:
      # We use Spotless in “ratchet mode” to incrementally enforce code
      # formatting throughout the project. In order to ensure feature branches
      # don't regress formatting when compared with the master branch, we need
      # to have a local copy of the master branch for comparison.
      - name: Checkout the master branch
        uses: actions/checkout@v3
        with:
          ref: master
      - name: Checkout the target branch
        uses: actions/checkout@v3
      - name: Setup Java
        uses: actions/setup-java@v3
        with:
          distribution: temurin
          java-version: 8
          cache: gradle

      - name: Download native libraries
        uses: actions/download-artifact@v3
        with:
          path: src/main/c/resources/native

      - name: Build the Java library
        run: ./gradlew build

      - name: Determine commit hash for artifact filename
        id: vars
        run: echo "short-rev=$(git rev-parse --short HEAD)" >>$GITHUB_OUTPUT
      - name: Upload build artifacts
        uses: actions/upload-artifact@v3
        with:
          name: nrjavaserial-${{steps.vars.outputs.short-rev}}
          path: build/libs/*.jar