core/pkgs/build-support/rust/build-rust-crate/helpers.nix

{ stdenv, lib }: {
  kernel = stdenv.hostPlatform.parsed.kernel.name;
  abi = stdenv.hostPlatform.parsed.abi.name;
  cpu = stdenv.hostPlatform.parsed.cpu.name;
  updateFeatures = f: up: functions:
    lib.deepSeq f (lib.foldl' (features: fun: fun features)
      (lib.attrsets.recursiveUpdate f up) functions);
  mapFeatures = features: map (fun: fun { features = features; });
  mkFeatures = feat:
    lib.foldl (features: featureName:
      if feat.${featureName} or false then
        [ featureName ] ++ features
      else
        features) [ ] (lib.attrNames feat);
  include = includedFiles: src:
    builtins.filterSource (path: type:
      lib.any (f:
        let p = toString (src + ("/" + f));
        in p == path || (lib.strings.hasPrefix (p + "/") path)) includedFiles)
    src;
  exclude = excludedFiles: src:
    builtins.filterSource (path: type:
      lib.all (f: !lib.strings.hasPrefix (toString (src + ("/" + f))) path)
      excludedFiles) src;
}