core/pkgs/stdenv/cross/default.nix

{ lib, localSystem, crossSystem, config, overlays, crossOverlays ? [ ] }:

let
  bootStages = import ../. {
    inherit lib localSystem overlays;

    crossSystem = localSystem;
    crossOverlays = [ ];

    # Ignore custom stdenvs when cross compiling for compatibility
    config = builtins.removeAttrs config [ "replaceStdenv" ];
  };

in lib.init bootStages ++ [

  # Regular native packages
  (somePrevStage:
    lib.last bootStages somePrevStage // {
      # It's OK to change the built-time dependencies
      allowCustomOverrides = true;
    })

  # Build tool Packages
  (vanillaPackages: {
    inherit config overlays;
    selfBuild = false;
    stdenv = assert vanillaPackages.stdenv.buildPlatform == localSystem;
      assert vanillaPackages.stdenv.hostPlatform == localSystem;
      assert vanillaPackages.stdenv.targetPlatform == localSystem;
      vanillaPackages.stdenv.override { targetPlatform = crossSystem; };
    # It's OK to change the built-time dependencies
    allowCustomOverrides = true;
  })

  # Run Packages
  (buildPackages:
    let
      adaptStdenv = if crossSystem.isStatic then
        buildPackages.stdenvAdapters.makeStatic
      else
        lib.id;
    in {
      inherit config;
      overlays = overlays ++ crossOverlays;
      selfBuild = false;
      stdenv = adaptStdenv (buildPackages.stdenv.override (old: rec {
        buildPlatform = localSystem;
        hostPlatform = crossSystem;
        targetPlatform = crossSystem;

        # Prior overrides are surely not valid as packages built with this run on
        # a different platform, and so are disabled.
        overrides = _: _: { };
        extraBuildInputs = [ ] # Old ones run on wrong platform
          ++ lib.optionals hostPlatform.isDarwin [
            buildPackages.targetPackages.darwin.apple_sdk.frameworks.CoreFoundation
          ];
        allowedRequisites = null;

        hasCC = !targetPlatform.isGhcjs;

        cc = if crossSystem.useiOSPrebuilt or false then
          buildPackages.darwin.iosSdkPkgs.clang
        else if crossSystem.useAndroidPrebuilt or false then
          buildPackages."androidndkPkgs_${crossSystem.ndkVer}".clang
        else if targetPlatform.isGhcjs
        # Need to use `throw` so tryEval for splicing works, ugh.  Using
        # `null` or skipping the attribute would cause an eval failure
        # `tryEval` wouldn't catch, wrecking accessing previous stages
        # when there is a C compiler and everything should be fine.
        then
          throw "no C compiler provided for this platform"
        else if crossSystem.isDarwin then
          buildPackages.llvmPackages.libcxxClang
        else if crossSystem.useLLVM or false then
          buildPackages.llvmPackages.clang
        else
          buildPackages.gcc;

        extraNativeBuildInputs = old.extraNativeBuildInputs
          ++ lib.optionals (hostPlatform.isLinux && !buildPlatform.isLinux)
          [ buildPackages.patchelf ] ++ lib.optional (let
            f = p:
              !p.isx86 || builtins.elem p.libc [ "musl" "wasilibc" "relibc" ]
              || p.isiOS || p.isGenode;
          in f hostPlatform && !(f buildPlatform))
          buildPackages.updateAutotoolsGnuConfigScriptsHook;
      }));
    })

]