depot/third_party/nixpkgs/pkgs/development/tools/haskell/hadrian/make-hadrian.nix

69 lines
2.6 KiB
Nix

# Hadrian is the build system used to (exclusively) build GHC. It can
# (theoretically) be used starting with GHC 9.4 and is required since 9.6. It is
# developed in the GHC source tree and specific to the GHC version it is released
# with, i.e. Hadrian always needs to be built from the same GHC source tree as
# the GHC we want to build.
#
# This fact makes it impossible to integrate Hadrian into our Haskell package
# sets which are also used to bootstrap GHC, since a package set can bootstrap
# multiple GHC versions (usually two major versions). A bootstrap set would need
# knowledge of the GHC it would eventually bootstrap which would make the logic
# unnecessarily complicated.
#
# Luckily Hadrian is, while annoying to bootstrap, relatively simple. Specifically
# all it requires to build is (relative to the GHC we are trying to build) a
# build->build GHC and build->build Haskell packages. We can get all of this
# from bootPkgs which is already passed to the GHC expression.
#
# The solution is the following: The GHC expression passes its source tree and
# version along with some parameters to this function (./make-hadrian.nix)
# which acts as a common expression builder for all Hadrian version as well as
# related packages that are managed in the GHC source tree. Its main job is to
# expose all possible compile time customization in a common interface and
# take care of all differences between Hadrian versions.
{
bootPkgs,
lib,
}:
{
# GHC source tree and version to build hadrian & friends from.
# These are passed on to the actual package expressions.
ghcSrc,
ghcVersion,
# Contents of a non-default UserSettings.hs to use when building hadrian, if any.
# Should be a string or null.
userSettings ? null,
}:
let
callPackage' =
f: args:
bootPkgs.callPackage f (
{
inherit ghcSrc ghcVersion;
}
// args
);
ghc-platform = callPackage' ./ghc-platform.nix { };
ghc-toolchain = callPackage' ./ghc-toolchain.nix {
inherit ghc-platform;
};
in
callPackage' ./hadrian.nix (
{
inherit userSettings;
}
// lib.optionalAttrs (lib.versionAtLeast ghcVersion "9.9") {
# Starting with GHC 9.9 development, additional in tree packages are required
# to build hadrian. (Hackage-released conditional dependencies are handled
# in ./hadrian.nix without requiring intervention here.)
inherit ghc-platform ghc-toolchain;
}
// lib.optionalAttrs (lib.versionAtLeast ghcVersion "9.11") {
# See https://gitlab.haskell.org/ghc/ghc/-/commit/145a6477854d4003a07573d5e7ffa0c9a64ae29c
Cabal = bootPkgs.Cabal_3_14_0_0;
}
)