Function _resolve_fast_native_entries

ci/meson/native_launchers.py:296–355

Resolve native launcher binaries for the Meson native file. Uses ctc-clang/ctc-clang++ native launchers which handle all platform- specific flags automatically (--target, --sysroot, -stdlib, includes, etc.) with near-zero startup overhead (~34ms vs ~1200ms for Python wrappers).

()

def _resolve_fast_native_entries() -> FastNativeEntries:
    """
    Resolve native launcher binaries for the Meson native file.

    Uses ctc-clang/ctc-clang++ native launchers which handle all platform-
    specific flags automatically (--target, --sysroot, -stdlib, includes, etc.)
    with near-zero startup overhead (~34ms vs ~1200ms for Python wrappers).

    Note: zccache wrapping is intentionally NOT applied here. The meson
    configure phase runs probes like ``<cc> -xc++ -E -v -`` to scan the
    compiler&#x27;s include search paths and capabilities. zccache (and other
    full-path compiler caches that meson does not recognise — see
    ``mesonbuild/envconfig.py:BinaryTable.parse_entry`` which only strips
    the literal strings ``'ccache'`` / ``'sccache'``) wraps those probes
    and causes them to hang or return non-parseable output, leading to
    "No include directory found" warnings followed by failing capability
    probes. Instead, zccache is applied as a post-patch on the generated
    ``build.ninja`` via ``inject_zccache_wrapping`` — probes run against
    the bare compiler, build runs through zccache as before. See issue
    #2714.

    Returns:
        FastNativeEntries with cc, cxx, and ar entries for the native file,
        or all-None fields if resolution fails (falls back to wrappers).
    """
    _none = FastNativeEntries(cc=None, cxx=None, ar=None)
    try:
        from clang_tool_chain.platform.paths import (
            find_tool_binary,
        )
    except ImportError:
        return _none

    try:
        ar_path = str(find_tool_binary("llvm-ar"))

        project_root = Path(__file__).resolve().parent.parent.parent
        ctc_c, ctc_cpp = _ensure_native_launcher(project_root)
        if ctc_c is None or ctc_cpp is None:
            return _none

        # Escape any single quotes in the path so the generated Meson
        # list-of-strings remains valid even if a path happens to contain
        # one. Paths under ``.cached/clang-native/`` are extremely unlikely
        # to contain ``'`` in practice, but defensive escaping costs nothing
        # and avoids a hard-to-debug native-file parse error.
        def _q(p: str) -> str:
            return p.replace("'", "\\'")

        return FastNativeEntries(
            cc=f"['{_q(ctc_c)}']",
            cxx=f"['{_q(ctc_cpp)}']",
            ar=f"['{_q(ar_path)}']",
        )

    except KeyboardInterrupt as ki:
        handle_keyboard_interrupt(ki)
        return _none  # unreachable, satisfies type checker