name: vmlinux.h

on:
  pull_request:
  push:
    branches:
      - main
  workflow_dispatch:
    inputs:
      kernel-ref:
        description: 'Kernel version (Git tag/ref)'
        required: true
        # Keep in sync with string used in `checkout` invocation below.
        default: 'v6.19'
  workflow_call:

jobs:
  gen-headers:
    name: Generate vmlinux.h (${{ matrix.arch }})
    runs-on: ubuntu-latest
    strategy:
      matrix:
        arch:
          - x86_64
          - aarch64
          - arm
          - loongarch64
          - ppc64le
          - riscv64
          - s390x

    steps:

      - uses: actions/checkout@v7

      - name: Check out Linux source
        uses: actions/checkout@v7
        with:
          repository: 'torvalds/linux'
          ref: ${{ github.event_name == 'workflow_dispatch' && github.event.inputs.kernel-ref || 'v6.19' }}
          fetch-depth: 1
          path: linux/

      - name: Check out pahole source
        uses: actions/checkout@v7
        with:
          repository: 'acmel/dwarves'
          ref: 'next'
          fetch-depth: 1
          path: pahole/

      - name: Install pahole
        shell: bash
        run: |
          sudo apt -y install cmake git libdw-dev libelf-dev
          cd pahole
          mkdir -p build
          cmake -B=build -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=/usr
          make -C build -j$(nproc)
          sudo make -C build install

      - name: Install dependencies
        shell: bash
        run: |
          ./scripts/install-dependencies.sh
          ./scripts/install-bpftool.sh

      - name: Generate ${{ matrix.arch }}/vmlinux.h
        shell: bash
        run: ./scripts/gen-vmlinux-header.sh ${{ matrix.arch }}

      - name: Upload headers
        uses: actions/upload-artifact@v7
        with:
          name: vmlinux.h-${{ matrix.arch }}
          if-no-files-found: error
          path: ./vmlinux.h/${{ matrix.arch }}

  combine-headers:
    name: Combine all vmlinux.h headers
    runs-on: ubuntu-latest
    needs: gen-headers

    steps:
      - name: Download all artifacts
        uses: actions/download-artifact@v8
        with:
          pattern: vmlinux.h-*

      - name: Reorganize headers
        shell: bash
        run: |
          mkdir -p vmlinux.h
          for dir in vmlinux.h-*/; do
            arch="${dir#vmlinux.h-}"
            arch="${arch%/}"
            # Map architecture names to match include/ directory structure
            target_arch="$arch"
            case "$arch" in
              ppc64le) target_arch="powerpc" ;;
            esac
            mkdir -p "vmlinux.h/$target_arch"
            mv "$dir"* "vmlinux.h/$target_arch/"
          done

      - name: Upload combined headers
        uses: actions/upload-artifact@v7
        with:
          name: vmlinux.h
          if-no-files-found: error
          path: ./vmlinux.h