NixOS · Mar 8, 2019 · Mar 8, 2019 · Mar 8, 2019
Showing with 76 additions and 11 deletions.

+1 −1 lib/default.nix

+2 −1 lib/trivial.nix

+1 −3 nixos/modules/system/activation/top-level.nix

+51 −0 pkgs/top-level/config.nix

+21 −6 pkgs/top-level/default.nix
diff --git a/lib/default.nix b/lib/default.nix
@@ -59,7 +59,7 @@ let
       stringLength sub substring tail;
     inherit (trivial) id const concat or and bitAnd bitOr bitXor bitNot
       boolToString mergeAttrs flip mapNullable inNixShell min max
-      importJSON warn info nixpkgsVersion version mod compare
+      importJSON warn info showWarnings nixpkgsVersion version mod compare
       splitByAndCompare functionArgs setFunctionArgs isFunction;
     inherit (fixedPoints) fix fix' converge extends composeExtensions
       makeExtensible makeExtensibleWithCustomName;

diff --git a/lib/trivial.nix b/lib/trivial.nix
@@ -259,9 +259,10 @@ rec {
   # TODO: figure out a clever way to integrate location information from
   # something like __unsafeGetAttrPos.
 
-  warn = msg: builtins.trace "WARNING: ${msg}";
+  warn = msg: builtins.trace "[1;31mwarning: ${msg}[0m";
   info = msg: builtins.trace "INFO: ${msg}";
 
+  showWarnings = warnings: res: lib.fold (w: x: warn w x) res warnings;
 
   ## Function annotations
 

diff --git a/nixos/modules/system/activation/top-level.nix b/nixos/modules/system/activation/top-level.nix
@@ -130,11 +130,9 @@ let
 
   failedAssertions = map (x: x.message) (filter (x: !x.assertion) config.assertions);
 
-  showWarnings = res: fold (w: x: builtins.trace "[1;31mwarning: ${w}[0m" x) res config.warnings;
-
   baseSystemAssertWarn = if failedAssertions != []
     then throw "\nFailed assertions:\n${concatStringsSep "\n" (map (x: "- ${x}") failedAssertions)}"
-    else showWarnings baseSystem;
+    else showWarnings config.warnings baseSystem;
 
   # Replace runtime dependencies
   system = fold ({ oldDependency, newDependency }: drv:

diff --git a/pkgs/top-level/config.nix b/pkgs/top-level/config.nix
@@ -0,0 +1,51 @@
+# This file defines the structure of the `config` nixpkgs option.
+
+{ lib, config, ... }:
+
+with lib;
+
+let
+
+  mkMeta = args: mkOption (builtins.removeAttrs args [ "feature" ] // {
+    type = args.type or (types.uniq types.bool);
+    default = args.default or false;
+    description = args.description or ''
+      Whether to ${args.feature} while evaluating nixpkgs.
+    '' + ''
+      Changing the default will not cause any rebuilds.
+    '';
+  });
+
+  mkMassRebuild = args: mkOption (builtins.removeAttrs args [ "feature" ] // {
+    type = args.type or (types.uniq types.bool);
+    default = args.default or false;
+    description = (args.description or ''
+      Whether to ${args.feature} while building nixpkgs packages.
+    '') + ''
+      Changing the default may cause a mass rebuild.
+    '';
+  });
+
+  options = {
+
+    /* Internal stuff */
+
+    warnings = mkOption {
+      type = types.listOf types.str;
+      default = [];
+      internal = true;
+    };
+
+    /* Config options */
+
+    doCheckByDefault = mkMassRebuild {
+      feature = "run <literal>checkPhase</literal> by default";
+    };
+
+  };
+
+in {
+
+  inherit options;
+
+}
diff --git a/pkgs/top-level/default.nix b/pkgs/top-level/default.nix
@@ -41,7 +41,7 @@
 } @ args:
 
 let # Rename the function arguments
-  configExpr = config;
+  config0 = config;
   crossSystem0 = crossSystem;
 
 in let
@@ -50,22 +50,37 @@ in let
   # Allow both:
   # { /* the config */ } and
   # { pkgs, ... } : { /* the config */ }
-  config =
-    if lib.isFunction configExpr
-    then configExpr { inherit pkgs; }
-    else configExpr;
+  config1 =
+    if lib.isFunction config0
+    then config0 { inherit pkgs; }
+    else config0;
 
   # 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 one.
-    builtins.intersectAttrs { platform = null; } config
+    builtins.intersectAttrs { platform = null; } config1
     // args.localSystem);
 
   crossSystem = if crossSystem0 == null then localSystem
                 else lib.systems.elaborate crossSystem0;
 
+  configEval = lib.evalModules {
+    modules = [
+      ./config.nix
+      ({ options, ... }: {
+        _file = "nixpkgs.config";
+        # filter-out known options, FIXME: remove this eventually
+        config = builtins.intersectAttrs options config1;
+      })
+    ];
+  };
+
+  # take all the rest as-is
+  config = lib.showWarnings configEval.config.warnings
+    (config1 // builtins.removeAttrs configEval.config [ "_module" ]);
+
   # 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
   # give `all-packages.nix` all the arguments to this function, even ones that