nixpkgs/pkgs/build-support/lib/meson.nix

{ stdenv, lib }:

let
  inherit (lib) boolToString optionals;

  # See https://mesonbuild.com/Reference-tables.html#cpu-families
  cpuFamily = platform: with platform;
    /**/ if isAarch32 then "arm"
    else if isx86_32  then "x86"
    else platform.uname.processor;

  makeMesonFlags = { mesonFlags ? [], ... }:
    let
      crossFile = builtins.toFile "cross-file.conf" ''
        [properties]
        bindgen_clang_arguments = ['-target', '${stdenv.targetPlatform.config}']
        needs_exe_wrapper = ${boolToString (!stdenv.buildPlatform.canExecute stdenv.hostPlatform)}

        [host_machine]
        system = '${stdenv.targetPlatform.parsed.kernel.name}'
        cpu_family = '${cpuFamily stdenv.targetPlatform}'
        cpu = '${stdenv.targetPlatform.parsed.cpu.name}'
        endian = ${if stdenv.targetPlatform.isLittleEndian then "'little'" else "'big'"}

        [binaries]
        llvm-config = 'llvm-config-native'
        rust = ['rustc', '--target', '${stdenv.targetPlatform.rust.rustcTargetSpec}']
      '';
      crossFlags = optionals (stdenv.hostPlatform != stdenv.buildPlatform) [ "--cross-file=${crossFile}" ];
    in crossFlags ++ mesonFlags;

in
{
  inherit makeMesonFlags;
}