Function check_env_flag

python/setup.py:215–216

(name: str, default: str = "")

def locate_llvm(build_dir: str = None) -> str:
    """Resolve the LLVM/MLIR install dir used to build the plugin.

    Order: LLVM_INSTALL_DIR env -> Triton build CMakeCache (LLVM_SYSPATH /
    LLVM_DIR) -> newest ~/.triton/llvm/llvm-* cache.