diff options
| -rw-r--r-- | lib/systems/default.nix | 18 | ||||
| -rw-r--r-- | lib/systems/platforms.nix | 2 | ||||
| -rw-r--r-- | pkgs/top-level/default.nix | 16 |
3 files changed, 29 insertions, 7 deletions
diff --git a/lib/systems/default.nix b/lib/systems/default.nix index 70d431837daa..d956969a18f9 100644 --- a/lib/systems/default.nix +++ b/lib/systems/default.nix @@ -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; } diff --git a/lib/systems/platforms.nix b/lib/systems/platforms.nix index 665950766f7e..4322c8e2ff68 100644 --- a/lib/systems/platforms.nix +++ b/lib/systems/platforms.nix @@ -474,7 +474,7 @@ rec { }; }; - selectPlatformBySystem = system: { + selectBySystem = system: { "i686-linux" = pc32; "x86_64-linux" = pc64; "armv5tel-linux" = sheevaplug; diff --git a/pkgs/top-level/default.nix b/pkgs/top-level/default.nix index 48dbe7118bc2..5d3da35c54fb 100644 --- a/pkgs/top-level/default.nix +++ b/pkgs/top-level/default.nix @@ -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 |