Add extraConfigs attribute inside options. This attribute is used to

insert definitions from an external location.  As opposed to other
defintions, these definitions are always embedded into a list which allow
to add multiple definitions with one module.

!!! This feature _should not_ be used as a new mean to define options.

svn path=/nixpkgs/trunk/; revision=17481

pkgs/lib/modules.nix

@@ -230,10 +230,14 @@ rec {
               }"
           );
 
-          config = lib.zipWithNames (modulesNames modules) (name: values:
+          config = lib.zipWithNames (modulesNames modules) (name: values_:
             let
               hasOpt = builtins.hasAttr name result.options;
               opt = lib.getAttr name result.options;
+              values = values_ ++
+                optionals
+                  (hasOpt && isOption opt && opt ? extraConfigs)
+                  opt.extraConfigs;
 
             in if hasOpt && isOption opt then
               let defs = evalProperties values; in

pkgs/lib/options.nix

@@ -25,6 +25,7 @@ rec {
     # merge (function used to merge definitions into one definition: [ /type/ ] -> /type/)
     # apply (convert the option value to ease the manipulation of the option result)
     # options (set of sub-options declarations & definitions)
+    # extraConfigs (list of possible configurations)
   };
 
   mapSubOptions = f: opt:
@@ -138,14 +139,17 @@ rec {
         assert opt1 ? merge -> ! opt2 ? merge;
         assert opt1 ? apply -> ! opt2 ? apply;
         assert opt1 ? type -> ! opt2 ? type;
-        if opt1 ? options || opt2 ? options then
+        opt1 // opt2
-          opt1 // opt2 // {
+        // optionalAttrs (opt1 ? options || opt2 ? options) {
             options =
                (toList (attrByPath ["options"] [] opt1))
             ++ (toList (attrByPath ["options"] [] opt2));
           }
-        else
+        // optionalAttrs (opt1 ? extraConfigs || opt2 ? extraConfigs) {
-          opt1 // opt2
+            extraConfigs =
+               (attrByPath ["extraConfigs"] [] opt1)
+            ++ (attrByPath ["extraConfigs"] [] opt2);
+          }
       )) {} opts;