action.yml

name: setup-macos-llvm
description: >
  macOS ARM64 setup shared by ci-macos.yml and ci-macos-e2e.yml: xlings +
  the xlings-managed LLVM + a dev mcpp sandbox wired to that exact LLVM.
  Exports LLVM_ROOT, CXX, MCPP_LLVM_VER, MCPP, XLINGS_BIN.

  Kept separate from bootstrap-mcpp: macOS does not reuse the ~/.mcpp cache
  lineage — it builds its sandbox from the freshly resolved LLVM package on
  every run, which is exactly the property the macOS job exists to prove.

inputs:
  xlings-version:
    description: xlings release to bootstrap from
    required: false
    # Floor imposed by the index, not a routine bump — see
    # .github/actions/bootstrap-mcpp/action.yml for why 0.4.69 is required
    # (two packages named `lua` in one repo need openxlings/xlings#381).
    default: '2026.8.30.2'

runs:
  using: composite
  steps:
    - name: Cache xlings
      uses: actions/cache@v4
      with:
        path: ~/.xlings
        key: xlings-macos15-arm64-v3-xl${{ inputs.xlings-version }}-${{ hashFiles('.xlings.json') }}
        restore-keys: |
          xlings-macos15-arm64-v3-xl${{ inputs.xlings-version }}-

    - name: Bootstrap xlings
      shell: bash
      env:
        XLINGS_NON_INTERACTIVE: '1'
        XLINGS_VERSION: ${{ inputs.xlings-version }}
      run: |
        WORK=$(mktemp -d)
        tarball="xlings-${XLINGS_VERSION}-macosx-arm64.tar.gz"
        # Retried and verified — .github/tools/fetch_release.sh. A bare curl
        # here is the `curl: (52) Empty reply from server` flake.
        bash "$GITHUB_WORKSPACE/.github/tools/fetch_release.sh" \
          "https://github.com/d2learn/xlings/releases/download/v${XLINGS_VERSION}/${tarball}" \
          "${WORK}/${tarball}"
        tar -xzf "${WORK}/${tarball}" -C "${WORK}"
        XLINGS_DIR="${WORK}/xlings-${XLINGS_VERSION}-macosx-arm64"
        "$XLINGS_DIR/subos/default/bin/xlings" self install
        export PATH="$HOME/.xlings/subos/default/bin:$PATH"
        xlings --version
        echo "PATH=$HOME/.xlings/subos/default/bin:$PATH" >> "$GITHUB_ENV"

    - name: Install LLVM via xlings
      shell: bash
      run: |
        # latest-first: test binaries now link the toolchain's own libc++
        # (A1 root fix in flags.cppm), so new llvm releases are
        # self-consistent — the macOS job is the proof for each new default.
        xlings install llvm -y || xlings install llvm@20.1.7 -y
        LLVM_ROOT=$(find "$HOME/.xlings" -path "*/xpkgs/xim-x-llvm/*/bin/clang++" | head -1 | xargs dirname | xargs dirname)
        ls "$LLVM_ROOT/bin/clang++"
        "$LLVM_ROOT/bin/clang++" --version
        echo "LLVM_ROOT=$LLVM_ROOT" >> "$GITHUB_ENV"
        echo "CXX=$LLVM_ROOT/bin/clang++" >> "$GITHUB_ENV"

    - name: Bootstrap mcpp via xlings
      shell: bash
      run: |
        # Pinned to .xlings.json, shared implementation. A bare
        # `xlings install mcpp` resolved 0.0.105 here on a cold cache — below
        # the index floor, which makes every descriptor read return nothing.
        MCPP=$(bash "$GITHUB_WORKSPACE/.github/tools/install_pinned_mcpp.sh" "$GITHUB_WORKSPACE")
        echo "MCPP=$MCPP" >> "$GITHUB_ENV"
        echo "XLINGS_BIN=$HOME/.xlings/subos/default/bin/xlings" >> "$GITHUB_ENV"

    - name: Configure dev mcpp sandbox to reuse xlings LLVM
      shell: bash
      run: |
        # Use EXACTLY the LLVM the install step resolved (env LLVM_ROOT) — a
        # version-glob pick chose a stale cached 20.1.7 next to the freshly
        # installed 22.1.8 and silently tested the wrong toolchain.
        LLVM_PKG="$LLVM_ROOT"
        test -d "$LLVM_PKG"
        LLVM_VER=$(basename "$LLVM_PKG")
        echo "MCPP_LLVM_VER=$LLVM_VER" >> "$GITHUB_ENV"
        MCPP_LLVM_LINK="$HOME/.mcpp/registry/data/xpkgs/xim-x-llvm/$LLVM_VER"
        printf '1\n' > "$LLVM_PKG/.mcpp_ok"

        mkdir -p "$HOME/.mcpp/registry/data/xpkgs/xim-x-llvm"
        rm -rf "$MCPP_LLVM_LINK"
        ln -s "$LLVM_PKG" "$MCPP_LLVM_LINK"

        mkdir -p "$HOME/.mcpp"
        cat > "$HOME/.mcpp/config.toml" <<EOF
        # mcpp global config for CI. Dev binaries under target/.../bin/mcpp
        # fall back to ~/.mcpp; keep its registry isolated while reusing
        # the LLVM package already installed by \`xlings install llvm\`.
        [xlings]
        binary = "$HOME/.xlings/subos/default/bin/xlings"

        [index]
        default = "mcpplibs"

        [index.repos."mcpplibs"]
        url = "https://github.com/mcpp-community/mcpp-index.git"

        [cache]
        search_ttl_seconds = 3600

        [build]
        default_jobs    = 0
        default_backend = "ninja"
        EOF

        cat "$HOME/.mcpp/config.toml"
        ls "$MCPP_LLVM_LINK/bin/clang++"