flakelight/builtinModules/packages.nix
Archit Gupta 9099db6c84 Avoid evaluating packages twice
Previously, the packages outputs would be evalutated using callPackage
on the package set, but the package set already contains the package. If
another package depends on it, the dependency would be the version from
the package set. By grabbing the packages from the package set, each
package only needs to be evaluated once.
2024-01-12 00:45:22 -08:00

88 lines
2.7 KiB
Nix

# flakelight -- Framework for simplifying flake setup
# Copyright (C) 2023 Archit Gupta <archit@accelbread.com>
# SPDX-License-Identifier: MIT
{ config, lib, inputs, flakelight, genSystems, ... }:
let
inherit (builtins) parseDrvName tryEval;
inherit (lib) filterAttrs findFirst mapAttrs mapAttrs' mkIf mkMerge mkOption
nameValuePair optionalAttrs;
inherit (lib.types) lazyAttrsOf nullOr str uniq;
inherit (flakelight) supportedSystem;
inherit (flakelight.types) overlay packageDef;
genPkg = pkgs: pkg: pkgs.callPackage pkg { };
genPkgs = pkgs: mapAttrs (_: genPkg pkgs) config.packages;
in
{
options = {
package = mkOption {
type = nullOr packageDef;
default = null;
};
packages = mkOption {
type = lazyAttrsOf packageDef;
default = { };
};
pname = mkOption {
type = nullOr str;
default = null;
};
packageOverlay = mkOption {
internal = true;
type = uniq overlay;
default = _: _: { };
};
};
config = mkMerge [
(mkIf (config.package != null) {
packages.default = config.package;
})
(mkIf (config.packages != { }) {
packageOverlay = final: prev:
let
getName = pkg: pkg.pname or (parseDrvName pkg.name).name;
inherit (prev.stdenv.hostPlatform) system;
baseNixpkgs = inputs.nixpkgs.legacyPackages.${system};
mockPkgs = import ../misc/nameMockedPkgs.nix prev;
defaultPkgName = findFirst (x: (tryEval x).success)
(throw ("Could not determine the name of the default package; " +
"please set the `pname` flakelight option to the intended name."))
[
(assert config.pname != null; config.pname)
(getName (mockPkgs.callPackage config.packages.default { }))
(getName (baseNixpkgs.callPackage config.packages.default { }))
(getName (import inputs.nixpkgs {
inherit (prev.stdenv.hostPlatform) system;
inherit (config.nixpkgs) config;
overlays = config.withOverlays ++ [ (final: _: genPkgs final) ];
}).default)
];
in
(optionalAttrs (config.packages ? default) {
${defaultPkgName} = genPkg final config.packages.default;
}) // genPkgs final;
overlay = final: prev: removeAttrs
(config.packageOverlay (final.appendOverlays config.withOverlays) prev)
[ "default" ];
outputs = rec {
packages = genSystems (pkgs:
filterAttrs (_: supportedSystem pkgs)
(mapAttrs (k: _: pkgs.${k}) config.packages));
checks = mapAttrs
(_: mapAttrs' (n: nameValuePair ("packages-" + n)))
packages;
};
})
];
}