lib.systems.parse.mkSystemFromSkeleton

The following is the current implementation of this function.

mkSystemFromSkeleton =
    {
      cpu,
      # Optional, but fallback too complex for here.
      # Inferred below instead.
      vendor ?
        assert false;
        null,
      kernel,
      # Also inferred below
      abi ?
        assert false;
        null,
    }@args:
    let
      getCpu = name: cpuTypes.${name} or (throw "Unknown CPU type: ${name}");
      getVendor = name: vendors.${name} or (throw "Unknown vendor: ${name}");
      getKernel = name: kernels.${name} or (throw "Unknown kernel: ${name}");
      getAbi = name: abis.${name} or (throw "Unknown ABI: ${name}");

      parsed = {
        cpu = getCpu args.cpu;
        vendor =
          if args ? vendor then
            getVendor args.vendor
          else if isDarwin parsed then
            vendors.apple
          else if isWindows parsed then
            vendors.pc
          else
            vendors.unknown;
        kernel =
          if hasPrefix "darwin" args.kernel then
            getKernel "darwin"
          else if hasPrefix "netbsd" args.kernel then
            getKernel "netbsd"
          else
            getKernel (removeAbiSuffix args.kernel);
        abi =
          if args ? abi then
            getAbi args.abi
          else if isLinux parsed || isWindows parsed then
            if isAarch32 parsed then
              if versionAtLeast (parsed.cpu.version or "0") "6" then abis.gnueabihf else abis.gnueabi
            # Default ppc64 BE to ELFv2
            else if isPower64 parsed && isBigEndian parsed then
              abis.gnuabielfv2
            else
              abis.gnu
          else
            abis.unknown;
      };

    in
    mkSystem parsed;