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Diffstat (limited to 'infra/libkookie/nixpkgs/pkgs/top-level/splice.nix')
| -rw-r--r-- | infra/libkookie/nixpkgs/pkgs/top-level/splice.nix | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/infra/libkookie/nixpkgs/pkgs/top-level/splice.nix b/infra/libkookie/nixpkgs/pkgs/top-level/splice.nix new file mode 100644 index 000000000000..a093442d3698 --- /dev/null +++ b/infra/libkookie/nixpkgs/pkgs/top-level/splice.nix @@ -0,0 +1,137 @@ +# 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 + + spliceReal = { pkgsBuildBuild, pkgsBuildHost, pkgsBuildTarget + , pkgsHostHost, pkgsHostTarget + , pkgsTargetTarget + }: let + mash = + # Other pkgs sets + pkgsBuildBuild // pkgsBuildTarget // pkgsHostHost // pkgsTargetTarget + # The same pkgs sets one probably intends + // pkgsBuildHost // pkgsHostTarget; + merge = name: { + inherit name; + value = let + defaultValue = mash.${name}; + # `or {}` is for the non-derivation attsert splicing case, where `{}` is the identity. + valueBuildBuild = pkgsBuildBuild.${name} or {}; + valueBuildHost = pkgsBuildHost.${name} or {}; + valueBuildTarget = pkgsBuildTarget.${name} or {}; + valueHostHost = throw "`valueHostHost` unimplemented: pass manually rather than relying on splice."; + valueHostTarget = pkgsHostTarget.${name} or {}; + valueTargetTarget = pkgsTargetTarget.${name} or {}; + augmentedValue = defaultValue + # TODO(@Ericson2314): Stop using old names after transition period + // (lib.optionalAttrs (pkgsBuildHost ? ${name}) { nativeDrv = valueBuildHost; }) + // (lib.optionalAttrs (pkgsHostTarget ? ${name}) { crossDrv = valueHostTarget; }) + // { + __spliced = + (lib.optionalAttrs (pkgsBuildBuild ? ${name}) { buildBuild = valueBuildBuild; }) + // (lib.optionalAttrs (pkgsBuildTarget ? ${name}) { buildTarget = valueBuildTarget; }) + // { hostHost = valueHostHost; } + // (lib.optionalAttrs (pkgsTargetTarget ? ${name}) { targetTarget = valueTargetTarget; + }); + }; + # Get the set of outputs of a derivation. If one derivation fails to + # evaluate we don't want to diverge the entire splice, so we fall back + # on {} + tryGetOutputs = value0: let + inherit (builtins.tryEval value0) success value; + in getOutputs (lib.optionalAttrs success value); + getOutputs = value: lib.genAttrs + (value.outputs or (lib.optional (value ? out) "out")) + (output: value.${output}); + in + # The derivation along with its outputs, which we recur + # on to splice them together. + if lib.isDerivation defaultValue then augmentedValue // spliceReal { + pkgsBuildBuild = tryGetOutputs valueBuildBuild; + pkgsBuildHost = tryGetOutputs valueBuildHost; + pkgsBuildTarget = tryGetOutputs valueBuildTarget; + pkgsHostHost = tryGetOutputs valueHostHost; + pkgsHostTarget = getOutputs valueHostTarget; + pkgsTargetTarget = tryGetOutputs valueTargetTarget; + # Just recur on plain attrsets + } else if lib.isAttrs defaultValue then spliceReal { + pkgsBuildBuild = valueBuildBuild; + pkgsBuildHost = valueBuildHost; + pkgsBuildTarget = valueBuildTarget; + pkgsHostHost = {}; + pkgsHostTarget = valueHostTarget; + pkgsTargetTarget = valueTargetTarget; + # 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)); + + splicePackages = { pkgsBuildBuild, pkgsBuildHost, pkgsBuildTarget + , pkgsHostHost, pkgsHostTarget + , pkgsTargetTarget + } @ args: + if actuallySplice then spliceReal args else pkgsHostTarget; + + splicedPackages = splicePackages { + inherit (pkgs) + pkgsBuildBuild pkgsBuildHost pkgsBuildTarget + pkgsHostHost pkgsHostTarget + pkgsTargetTarget + ; + } // { + # These should never be spliced under any circumstances + inherit (pkgs) + pkgsBuildBuild pkgsBuildHost pkgsBuildTarget + pkgsHostHost pkgsHostTarget + pkgsTargetTarget + buildPackages pkgs targetPackages + ; + inherit (pkgs.stdenv) buildPlatform targetPlatform hostPlatform; + }; + + splicedPackagesWithXorg = splicedPackages // builtins.removeAttrs splicedPackages.xorg [ + "callPackage" "newScope" "overrideScope" "packages" + ]; + +in + +{ + inherit splicePackages; + + # 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 splicedPackagesWithXorg; + + newScope = extra: lib.callPackageWith (splicedPackagesWithXorg // extra); + + # Haskell package sets need this because they reimplement their own + # `newScope`. + __splicedPackages = splicedPackages // { recurseForDerivations = false; }; +} |