mirror of
https://github.com/NixOS/nixpkgs.git
synced 2024-11-24 22:50:49 +00:00
863d79b364
Each bootstrapping stage ought to just depend on the previous stage, but poorly-written compilers break this elegence. This provides an easy-enough way to depend on the next stage: targetPackages. PLEASE DO NOT USE IT UNLESS YOU MUST! I'm hoping someday in a pleasant future I can revert this commit :)
86 lines
3.9 KiB
Nix
86 lines
3.9 KiB
Nix
# The `splicedPackages' package set, and its use by `callPackage`
|
|
#
|
|
# The `buildPackages` pkg set is a new concept, and the vast majority package
|
|
# expression (the other *.nix files) are not designed with it in mind. This
|
|
# presents us with a problem with how to get the right version (build-time vs
|
|
# run-time) of a package to a consumer that isn't used to thinking so cleverly.
|
|
#
|
|
# The solution is to splice the package sets together as we do below, so every
|
|
# `callPackage`d expression in fact gets both versions. Each# derivation (and
|
|
# each derivation's outputs) consists of the run-time version, augmented with a
|
|
# `nativeDrv` field for the build-time version, and `crossDrv` field for the
|
|
# run-time version.
|
|
#
|
|
# We could have used any names we want for the disambiguated versions, but
|
|
# `crossDrv` and `nativeDrv` were somewhat similarly used for the old
|
|
# cross-compiling infrastructure. The names are mostly invisible as
|
|
# `mkDerivation` knows how to pull out the right ones for `buildDepends` and
|
|
# friends, but a few packages use them directly, so it seemed efficient (to
|
|
# @Ericson2314) to reuse those names, at least initially, to minimize breakage.
|
|
#
|
|
# For performance reasons, rather than uniformally splice in all cases, we only
|
|
# do so when `pkgs` and `buildPackages` are distinct. The `actuallySplice`
|
|
# parameter there the boolean value of that equality check.
|
|
lib: pkgs: actuallySplice:
|
|
|
|
let
|
|
defaultBuildScope = pkgs.buildPackages // pkgs.buildPackages.xorg;
|
|
# TODO(@Ericson2314): we shouldn't preclude run-time fetching by removing
|
|
# these attributes. We should have a more general solution for selecting
|
|
# whether `nativeDrv` or `crossDrv` is the default in `defaultScope`.
|
|
pkgsWithoutFetchers = lib.filterAttrs (n: _: !lib.hasPrefix "fetch" n) pkgs;
|
|
defaultRunScope = pkgsWithoutFetchers // pkgs.xorg;
|
|
|
|
splicer = buildPkgs: runPkgs: let
|
|
mash = buildPkgs // runPkgs;
|
|
merge = name: {
|
|
inherit name;
|
|
value = let
|
|
defaultValue = mash.${name};
|
|
buildValue = buildPkgs.${name} or {};
|
|
runValue = runPkgs.${name} or {};
|
|
augmentedValue = defaultValue
|
|
// (lib.optionalAttrs (buildPkgs ? ${name}) { nativeDrv = buildValue; })
|
|
// (lib.optionalAttrs (runPkgs ? ${name}) { crossDrv = runValue; });
|
|
# Get the set of outputs of a derivation
|
|
getOutputs = value:
|
|
lib.genAttrs (value.outputs or []) (output: value.${output});
|
|
in
|
|
# Certain *Cross derivations will fail assertions, but we need their
|
|
# nativeDrv. We are assuming anything that fails to evaluate is an
|
|
# attrset (including derivation) and thus can be unioned.
|
|
if !(builtins.tryEval defaultValue).success then augmentedValue
|
|
# The derivation along with its outputs, which we recur
|
|
# on to splice them together.
|
|
else if lib.isDerivation defaultValue then augmentedValue
|
|
// splicer (getOutputs buildValue) (getOutputs runValue)
|
|
# Just recur on plain attrsets
|
|
else if lib.isAttrs defaultValue then splicer buildValue runValue
|
|
# Don't be fancy about non-derivations. But we could have used used
|
|
# `__functor__` for functions instead.
|
|
else defaultValue;
|
|
};
|
|
in lib.listToAttrs (map merge (lib.attrNames mash));
|
|
|
|
splicedPackages =
|
|
if actuallySplice
|
|
then splicer defaultBuildScope defaultRunScope // {
|
|
# These should never be spliced under any circumstances
|
|
inherit (pkgs) pkgs buildPackages __targetPackages
|
|
buildPlatform targetPlatform hostPlatform;
|
|
}
|
|
else pkgs // pkgs.xorg;
|
|
|
|
in
|
|
|
|
{
|
|
# We use `callPackage' to be able to omit function arguments that can be
|
|
# obtained `pkgs` or `buildPackages` and their `xorg` package sets. Use
|
|
# `newScope' for sets of packages in `pkgs' (see e.g. `gnome' below).
|
|
callPackage = pkgs.newScope {};
|
|
|
|
callPackages = lib.callPackagesWith splicedPackages;
|
|
|
|
newScope = extra: lib.callPackageWith (splicedPackages // extra);
|
|
}
|