llvm-trunk-linux-mainline.yml

name: Test workflow with LLVM trunk and Linux mainline

on:
  push:
    branches:
    - llvm-trunk
    - llvm-trunk-next
    paths:
    - '.github/workflows/llvm-trunk-linux-mainline.yml'
    - 'ci/linux-mainline/**'
    - 'patches/v2.0/**'
    - 'scripts/**'
  workflow_dispatch:
  schedule:
  # Meaningless hh:mm field to avoid peak control traffic on GitHub
  - cron: '44 22 * * *'

# Allow at most one run from any workflow in this repo at the same time, as most
# of them will operate on some shared directories of self-hosted runners and
# interfere with each other. Without this setting, the below could happen:
#
#                T1      T2      T3      T4
#     runner1 -(R1J1--------------------R1J2)-
#             ---------(R2J1----R2J2)---------
#
# Now:
#
#                T1      T2      T3      T4      T5      T6
#     runner1 -(R1J1----R1J2)--xxxxxxxxxxxxxx--xxxxxxxxxxxxxx-
#             -xxxxxxxxxxxxxx--(R2J1----R2J2)--xxxxxxxxxxxxxx-
#     runner2 -xxxxxxxxxxxxxx--xxxxxxxxxxxxxx--(R3J1----R3J2)-
#
# Ideally we want a single runner to finish all jobs from a workflow before
# accepting any other job. But I don't know how.
#
#                T1      T2      T3      T4      T5      T6
#     runner1 -(R1J1----R1J2)--xxxxxxxxxxxxxx-----------------
#             -xxxxxxxxxxxxxx--(R3J1----R3J2)-----------------
#     runner2 ---------(R2J1----R2J2)--xxxxxxxxxxxxxx---------
#             ---------xxxxxxxxxxxxxx--(R4J1----R4J2)---------
#
# Or maybe we should redesign the abstraction: what ought to be workflows? what
# ought to be jobs? and what ought to be steps?

concurrency:
  group: ${{ github.repository }}

env:
  MCDC_HOME: /home/github-runner/mcdc-workdir

jobs:
  find_runner:
    name: Find an available self-hosted runner
    runs-on: self-hosted
    # Enforce this same runner for all later jobs that depend on this one
    # FIXME this requires each runner has a label the same as its name
    outputs:
      runner_name: ${{ runner.name }}
    # Dummy, do nothing
    steps:
    - uses: actions/checkout@v4

  install_deps:
    name: 1. Install dependencies
    needs: find_runner
    # Enforce the same runner
    runs-on: ${{ needs.find_runner.outputs.runner_name }}
    outputs:
      runner_name: ${{ runner.name }}
    steps:
    - uses: actions/checkout@v4
    - name: Install dependencies
      run: ./ci/linux-mainline/1_install_deps.sh

  pull_source:
    name: 2. Pull the source code and apply patches
    needs: install_deps
    # Enforce the same runner
    runs-on: ${{ needs.install_deps.outputs.runner_name }}
    outputs:
      runner_name: ${{ runner.name }}
    steps:
    - uses: actions/checkout@v4
    - name: Create a workspace from clean slate
      run: |
        rm -rf $MCDC_HOME
        mkdir -p $MCDC_HOME
    - name: Pull the source code and apply patches
      run: ./ci/linux-mainline/2_pull_source.sh ${{ github.repository }} ${{ github.ref_name }}

  get_llvm:
    name: 3. Get LLVM
    needs: pull_source
    # Enforce the same runner
    runs-on: ${{ needs.pull_source.outputs.runner_name }}
    outputs:
      runner_name: ${{ runner.name }}
    steps:
    - uses: actions/checkout@v4
    - name: Build from source
      run: ./ci/linux-mainline/3_get_llvm.sh
    - name: Print LLVM build resource usage
      run: |
        cat /tmp/time.log
        du -sh $MCDC_HOME/llvm-project

  build_kernel:
    name: 4. Build the kernel
    needs: get_llvm
    # Enforce the same runner
    runs-on: ${{ needs.get_llvm.outputs.runner_name }}
    outputs:
      runner_name: ${{ runner.name }}
    steps:
    - uses: actions/checkout@v4
    - name: Set up LLVM path
      run: echo "$MCDC_HOME/llvm-project/build/bin" >> $GITHUB_PATH
    - name: Print toolchain version
      run: |
        clang -v
        llc --version
    - name: Build the kernel
      run: ./ci/linux-mainline/4_build_kernel.sh
    - name: Print full kernel build log
      run: cat /tmp/make.log
    - name: Print kernel build resource usage
      run: |
        cat /tmp/time.log
        du -sh $MCDC_HOME/linux
    - name: Print kernel binary layout
      run: |
        llvm-readelf --sections -W $MCDC_HOME/linux/vmlinux

  boot_kernel_and_collect_coverage:
    name: 5. Boot the kernel and collect coverage
    needs: build_kernel
    # Enforce the same runner
    runs-on: ${{ needs.build_kernel.outputs.runner_name }}
    outputs:
      runner_name: ${{ runner.name }}
    steps:
    - uses: actions/checkout@v4
    - name: Set up LLVM path
      run: echo "$MCDC_HOME/llvm-project/build/bin" >> $GITHUB_PATH
    - name: Print toolchain version
      run: |
        clang -v
        llc --version
    - name: Boot the kernel and collect coverage
      run: ./ci/linux-mainline/5_boot_kernel_and_collect_coverage.sh
    - name: Print the index of coverage report (immediately after reset)
      run: cat $MCDC_HOME/analysis_reset/text-coverage-reports/index.txt
    - name: Print the index of coverage report
      run: cat $MCDC_HOME/analysis/text-coverage-reports/index.txt