nixpkgs/pkgs/top-level/pkg-config/defaultPkgConfigPackages.nix

/*
  A set of aliases to be used in generated expressions.

  In case of ambiguity, this will pick a sensible default.

  This was initially based on cabal2nix's mapping.

  It'd be nice to generate this mapping, based on a set of derivations.
  It can not be fully automated, so it should be a expression or tool
  that makes suggestions about which pkg-config module names can be added.
*/
pkgs:

let
  inherit (pkgs) lib;
  inherit (lib)
    all
    flip
    mapAttrs
    mapAttrsToList
    getAttrFromPath
    importJSON
    ;

  data = importJSON ./pkg-config-data.json;
  inherit (data) modules;

  platform = pkgs.stdenv.hostPlatform;

  isSupported =
    moduleData:
    moduleData ? supportedWhenPlatformAttrsEqual
    -> all (x: x) (
      mapAttrsToList (
        k: v: platform ? ${k} && platform.${k} == v
      ) moduleData.supportedWhenPlatformAttrsEqual
    );

  modulePkgs = flip mapAttrs modules (
    _moduleName: moduleData:
    if moduleData ? attrPath && isSupported moduleData then
      getAttrFromPath moduleData.attrPath pkgs
    else
      null
  );

in
modulePkgs