Elaborate localSystem and crossSystem in a consistent manner

This commit is contained in:
John Ericson 2017-03-23 20:49:28 -04:00
parent d86caa3216
commit 3efc661a1d
3 changed files with 29 additions and 7 deletions

View file

@ -2,4 +2,22 @@ rec {
doubles = import ./doubles.nix;
parse = import ./parse.nix;
platforms = import ./platforms.nix;
# Elaborate a `localSystem` or `crossSystem` so that it contains everything
# necessary.
#
# `parsed` is inferred from args, both because there are two options with one
# clearly prefered, and to prevent cycles. A simpler fixed point where the RHS
# always just used `final.*` would fail on both counts.
elaborate = args: let
final = {
# Prefer to parse `config` as it is strictly more informative.
parsed = parse.mkSystemFromString (if args ? config then args.config else args.system);
# Either of these can be losslessly-extracted from `parsed` iff parsing succeeds.
system = parse.doubleFromSystem final.parsed;
config = parse.tripleFromSystem final.parsed;
# Just a guess, based on `system`
platform = platforms.selectBySystem final.system;
} // args;
in final;
}

View file

@ -474,7 +474,7 @@ rec {
};
};
selectPlatformBySystem = system: {
selectBySystem = system: {
"i686-linux" = pc32;
"x86_64-linux" = pc64;
"armv5tel-linux" = sheevaplug;

View file

@ -40,6 +40,7 @@
let # Rename the function arguments
configExpr = config;
crossSystem0 = crossSystem;
in let
lib = import ../../lib;
@ -52,12 +53,15 @@ in let
then configExpr { inherit pkgs; }
else configExpr;
# Allow setting the platform in the config file. Otherwise, let's use a
# reasonable default.
localSystem =
{ platform = lib.systems.platforms.selectPlatformBySystem args.localSystem.system; }
// builtins.intersectAttrs { platform = null; } config
// args.localSystem;
# From a minimum of `system` or `config` (actually a target triple, *not*
# nixpkgs configuration), infer the other one and platform as needed.
localSystem = lib.systems.elaborate (
# Allow setting the platform in the config file. This take precedence over
# the inferred platform, but not over an explicitly passed-in onw.
builtins.intersectAttrs { platform = null; } config
// args.localSystem);
crossSystem = lib.mapNullable lib.systems.elaborate crossSystem0;
# A few packages make a new package set to draw their dependencies from.
# (Currently to get a cross tool chain, or forced-i686 package.) Rather than