cargoxx/flake.nix

{
  description = "cargoxx";

  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
    flake-utils.url = "github:numtide/flake-utils";
  };

  outputs = { self, nixpkgs, flake-utils }:
    flake-utils.lib.eachDefaultSystem (system:
      let
        pkgs = import nixpkgs { inherit system; };

        cargoxx-bin = pkgs.gcc15Stdenv.mkDerivation {
          pname = "cargoxx";
          version = "0.1.0";
          src = ./.;
          nativeBuildInputs = [ pkgs.cmake pkgs.ninja ];
          buildInputs = [ pkgs.sqlite pkgs.reproc pkgs.catch2_3 ];
          configurePhase = ''
            cmake -S build -B build/release -G Ninja \
              -DCMAKE_BUILD_TYPE=Release
          '';
          buildPhase = ''
            cmake --build build/release
          '';
          installPhase = ''
            mkdir -p $out/bin
            cp build/release/cargoxx $out/bin/
          '';
          hardeningDisable = [ "all" ];
        };

        buildCppPackage = { src, name ? null, ... }@args:
          let
            lock = builtins.fromTOML (builtins.readFile (src + "/Cargoxx.lock"));
            isDep = p: p ? linkdb_source;
            isRoot = p: !(isDep p);
            root = builtins.head (builtins.filter isRoot lock.package);
            depPkgs = builtins.filter isDep lock.package;
            pname = if name != null then name else root.name;

            pkgsAt = rev:
              (builtins.getFlake "github:NixOS/nixpkgs/${rev}")
                .legacyPackages.${system};

            evalDep = p:
              let rev = if (p ? nixpkgs_rev) && (p.nixpkgs_rev != "")
                        then p.nixpkgs_rev
                        else lock.nixpkgs_rev;
              in (pkgsAt rev).${p.nixpkgs_attr};

            depInputs = map evalDep depPkgs;

            usesPkgConfig = builtins.any
              (p: (p.linkdb_source or "") == "pkg-config") depPkgs;

            nixpkgsSource = (builtins.getFlake
              "github:NixOS/nixpkgs/${lock.nixpkgs_rev}").outPath;
            flakeUtilsSource = (builtins.getFlake
              "github:numtide/flake-utils/${lock.flake_utils_rev}").outPath;

            mkDepTomlEntry = p:
              let
                derivation = evalDep p;
                rev = if (p ? nixpkgs_rev) && (p.nixpkgs_rev != "")
                      then p.nixpkgs_rev else lock.nixpkgs_rev;
              in ''
                [[dep]]
                name = "${p.name}"
                nixpkgs_attr = "${p.nixpkgs_attr}"
                nixpkgs_rev = "${rev}"
                store_path = "${derivation}"
              '';

            vendorToml = pkgs.writeText "vendor.toml" (''
              schema = 1

              [nixpkgs]
              rev = "${lock.nixpkgs_rev}"
              store_path = "${nixpkgsSource}"

              [flake_utils]
              rev = "${lock.flake_utils_rev}"
              store_path = "${flakeUtilsSource}"
            '' + builtins.concatStringsSep "\n" (map mkDepTomlEntry depPkgs));
          in pkgs.gcc15Stdenv.mkDerivation {
            inherit pname src;
            version = root.version;
            nativeBuildInputs =
              [ cargoxx-bin pkgs.cmake pkgs.ninja ]
              ++ pkgs.lib.optional usesPkgConfig pkgs.pkg-config;
            buildInputs = depInputs;
            dontConfigure = true;
            buildPhase = ''
              export HOME=$(mktemp -d)
              cargoxx build --release --offline --vendor ${vendorToml}
            '';
            installPhase = ''
              mkdir -p $out/bin
              cp build/release/${pname}     $out/bin/ 2>/dev/null || \
              cp build/release/${pname}_bin $out/bin/${pname}
            '';
            hardeningDisable = [ "all" ];
          };
      in {
        packages.default = cargoxx-bin;
        lib.buildCppPackage = buildCppPackage;
        devShells.default = pkgs.gcc15Stdenv.mkDerivation {
          name = "cargoxx-dev";
          version = "0.1.0";
          nativeBuildInputs = [ pkgs.ninja pkgs.cmake ];
          buildInputs = [ pkgs.reproc pkgs.sqlite pkgs.catch2_3 ];
          hardeningDisable = [ "all" ];
        };
      });
}