name: Build libkrun (linux, glibc 2.35)

# Rebuild the bundled linux libkrun.so on ubuntu-22.04 so its glibc floor is
# 2.35 — the same floor the release binaries get (they also build on 22.04, see
# release.yml). A libkrun built on a newer distro (e.g. Ubuntu 24.04 / glibc
# 2.39) loads fine there but fails on 22.04 with "GLIBC_2.39 not found", which is
# exactly how a hand-built lib slipped a 2.39 floor into v1.2.0.
#
# SKIP_LIBKRUNFW=1: reuse the committed lib/linux-<arch>/libkrunfw.so (it wraps a
# guest-kernel blob, floor GLIBC_2.2 — host-glibc-independent), so we skip the
# multi-minute kernel rebuild and only recompile libkrun itself.
#
# Dispatch-only. Uploads lib/linux-<arch>/ as an artifact; the rebuilt .so is
# then committed into the repo (git-LFS) and shipped in the next release.

on:
  workflow_dispatch:
    inputs:
      rebuild_libkrunfw:
        description: "Rebuild libkrunfw from source (full guest-kernel rebuild) instead of reusing the committed .so. Needed when a libkrunfw patch changed the guest kernel."
        type: boolean
        default: false

jobs:
  build:
    name: libkrun ${{ matrix.arch }}
    strategy:
      fail-fast: false
      matrix:
        include:
          - arch: x86_64
            runner: ubuntu-22.04
          - arch: aarch64
            runner: ubuntu-22.04-arm
    runs-on: ${{ matrix.runner }}
    steps:
      - uses: actions/checkout@v4
        with:
          submodules: recursive   # libkrun links against the libkrunfw source
          lfs: true               # committed libkrunfw.so reused under SKIP_LIBKRUNFW

      - name: Free disk space
        run: |
          sudo rm -rf /usr/share/dotnet /opt/ghc /usr/local/lib/android \
            /opt/hostedtoolcache/CodeQL 2>/dev/null || true
          df -h / | tail -1

      # By default reuse the committed libkrunfw.so (skips the multi-minute guest
      # kernel rebuild). When a libkrunfw patch changed the guest kernel, dispatch
      # with rebuild_libkrunfw=true so libkrunfw.so is rebuilt from the submodule
      # source and picked up here.
      - name: Build libkrun (GPU=1)
        run: |
          if [ "${{ inputs.rebuild_libkrunfw }}" = "true" ]; then
            echo "Rebuilding libkrunfw from source"
            GPU=1 ./scripts/build-libkrun-linux.sh
          else
            SKIP_LIBKRUNFW=1 GPU=1 ./scripts/build-libkrun-linux.sh
          fi

      - name: Assert glibc floor <= 2.35
        run: |
          so="lib/linux-${{ matrix.arch }}/libkrun.so"
          maxv=$(objdump -T "$so" | grep -oE 'GLIBC_[0-9]+\.[0-9]+' \
            | sed 's/GLIBC_//' | sort -V | tail -1)
          echo "max GLIBC required by $so: ${maxv:-none}"
          if [ -n "$maxv" ] && [ "$(printf '%s\n2.35\n' "$maxv" | sort -V | tail -1)" != "2.35" ]; then
            echo "::error::$so requires glibc $maxv (> 2.35) — floor not lowered"
            exit 1
          fi
          echo "OK: glibc floor is <= 2.35"

      - uses: actions/upload-artifact@v4
        with:
          name: libkrun-linux-${{ matrix.arch }}
          path: lib/linux-${{ matrix.arch }}/
          if-no-files-found: error

  # Cross-build the Windows libkrunfw.dll (guest kernel wrapped for a Windows
  # host) with mingw-w64 on Linux. The kernel builds with native gcc; only the
  # final bundle link uses the mingw toolchain (Makefile OS=Windows path). Only
  # runs when refreshing libkrunfw, since the .dll wraps the guest kernel.
  windows-libkrunfw:
    name: libkrunfw.dll (windows cross)
    if: ${{ inputs.rebuild_libkrunfw }}
    runs-on: ubuntu-22.04
    steps:
      - uses: actions/checkout@v4
        with:
          submodules: recursive
          lfs: false

      - name: Free disk space
        run: |
          sudo rm -rf /usr/share/dotnet /opt/ghc /usr/local/lib/android \
            /opt/hostedtoolcache/CodeQL 2>/dev/null || true

      - name: Install build + mingw toolchain
        run: |
          sudo apt-get update
          sudo apt-get install -y make gcc bc bison flex libelf-dev libssl-dev \
            python3-pyelftools curl xz-utils cpio kmod gcc-mingw-w64-x86-64

      - name: Build libkrunfw.dll (mingw cross)
        run: cd libkrunfw && make OS=Windows -j"$(nproc)"

      - uses: actions/upload-artifact@v4
        with:
          name: libkrunfw-windows-x86_64
          path: libkrunfw/libkrunfw.dll
          if-no-files-found: error