NixOS · Jan 9, 2020 · Jan 9, 2020 · Jan 9, 2020 · Jan 9, 2020 · Jan 9, 2020
diff --git a/lib/default.nix b/lib/default.nix
@@ -101,7 +101,7 @@ let
       cleanSource sourceByRegex sourceFilesBySuffices
       commitIdFromGitRepo cleanSourceWith pathHasContext
       canCleanSource;
-    inherit (modules) evalModules closeModules unifyModuleSyntax
+    inherit (modules) evalModules unifyModuleSyntax
       applyIfFunction mergeModules
       mergeModules' mergeOptionDecls evalOptionValue mergeDefinitions
       pushDownProperties dischargeProperties filterOverrides
@@ -110,7 +110,7 @@ let
       mkFixStrictness mkOrder mkBefore mkAfter mkAliasDefinitions
       mkAliasAndWrapDefinitions fixMergeModules mkRemovedOptionModule
       mkRenamedOptionModule mkMergedOptionModule mkChangedOptionModule
-      mkAliasOptionModule doRename filterModules;
+      mkAliasOptionModule doRename;
     inherit (options) isOption mkEnableOption mkSinkUndeclaredOptions
       mergeDefaultOption mergeOneOption mergeEqualOption getValues
       getFiles optionAttrSetToDocList optionAttrSetToDocList'

diff --git a/lib/modules.nix b/lib/modules.nix
@@ -59,9 +59,12 @@ rec {
         };
       };
 
-      closed = closeModules (modules ++ [ internalModule ]) ({ inherit config options lib; } // specialArgs);
+      collected = collectModules
+        (specialArgs.modulesPath or "")
+        (modules ++ [ internalModule ])
+        ({ inherit config options lib; } // specialArgs);
 
-      options = mergeModules prefix (reverseList (filterModules (specialArgs.modulesPath or "") closed));
+      options = mergeModules prefix (reverseList collected);
 
       # Traverse options and extract the option values into the final
       # config set.  At the same time, check whether all option
@@ -87,31 +90,76 @@ rec {
       result = { inherit options config; };
     in result;
 
+  # collectModules :: (modulesPath: String) -> (modules: [ Module ]) -> (args: Attrs) -> [ Module ]
+  #
+  # Collects all modules recursively through `import` statements, filtering out
+  # all modules in disabledModules.
+  collectModules = let
 
- # Filter disabled modules. Modules can be disabled allowing
- # their implementation to be replaced.
- filterModules = modulesPath: modules:
-   let
-     moduleKey = m: if isString m then toString modulesPath + "/" + m else toString m;
-     disabledKeys = map moduleKey (concatMap (m: m.disabledModules) modules);
-   in
-     filter (m: !(elem m.key disabledKeys)) modules;
+      # Like unifyModuleSyntax, but also imports paths and calls functions if necessary
+      loadModule = args: fallbackFile: fallbackKey: m:
+        if isFunction m || isAttrs m then
+          unifyModuleSyntax fallbackFile fallbackKey (applyIfFunction fallbackKey m args)
+        else unifyModuleSyntax (toString m) (toString m) (applyIfFunction (toString m) (import m) args);
 
-  /* Close a set of modules under the ‘imports’ relation. */
-  closeModules = modules: args:
-    let
-      toClosureList = file: parentKey: imap1 (n: x:
-        if isAttrs x || isFunction x then
-          let key = "${parentKey}:anon-${toString n}"; in
-          unifyModuleSyntax file key (applyIfFunction key x args)
-        else
-          let file = toString x; key = toString x; in
-          unifyModuleSyntax file key (applyIfFunction key (import x) args));
-    in
-      builtins.genericClosure {
-        startSet = toClosureList unknownModule "" modules;
-        operator = m: toClosureList m._file m.key m.imports;
-      };
+      /*
+      Collects all modules recursively into the form
+
+        {
+          disabled = [ <list of disabled modules> ];
+          # All modules of the main module list
+          modules = [
+            {
+              key = <key1>;
+              module = <module for key1>;
+              # All modules imported by the module for key1
+              modules = [
+                {
+                  key = <key1-1>;
+                  module = <module for key1-1>;
+                  # All modules imported by the module for key1-1
+                  modules = [ ... ];
+                }
+                ...
+              ];
+            }
+            ...
+          ];
+        }
+      */
+      collectStructuredModules =
+        let
+          collectResults = modules: {
+            disabled = concatLists (catAttrs "disabled" modules);
+            inherit modules;
+          };
+        in parentFile: parentKey: initialModules: args: collectResults (imap1 (n: x:
+          let
+            module = loadModule args parentFile "${parentKey}:anon-${toString n}" x;
+            collectedImports = collectStructuredModules module._file module.key module.imports args;
+          in {
+            key = module.key;
+            module = module;
+            modules = collectedImports.modules;
+            disabled = module.disabledModules ++ collectedImports.disabled;
+          }) initialModules);
+
+      # filterModules :: String -> { disabled, modules } -> [ Module ]
+      #
+      # Filters a structure as emitted by collectStructuredModules by removing all disabled
+      # modules recursively. It returns the final list of unique-by-key modules
+      filterModules = modulesPath: { disabled, modules }:
+        let
+          moduleKey = m: if isString m then toString modulesPath + "/" + m else toString m;
+          disabledKeys = listToAttrs (map (k: nameValuePair (moduleKey k) null) disabled);
+          keyFilter = filter (attrs: ! disabledKeys ? ${attrs.key});
+        in map (attrs: attrs.module) (builtins.genericClosure {
+          startSet = keyFilter modules;
+          operator = attrs: keyFilter attrs.modules;
+        });
+
+    in modulesPath: initialModules: args:
+      filterModules modulesPath (collectStructuredModules unknownModule "" initialModules args);
 
   /* Massage a module into canonical form, that is, a set consisting
      of ‘options’, ‘config’ and ‘imports’ attributes. */

diff --git a/lib/tests/modules.sh b/lib/tests/modules.sh
@@ -177,6 +177,12 @@ checkConfigOutput "true" config.submodule.outer ./declare-submoduleWith-modules.
 # Temporarily disabled until https://github.com/NixOS/nixpkgs/pull/76861
 #checkConfigOutput "true" config.submodule.enable ./declare-submoduleWith-path.nix
 
+# Check that disabledModules works recursively and correctly
+checkConfigOutput "true" config.enable ./disable-recursive/main.nix
+checkConfigOutput "true" config.enable ./disable-recursive/{main.nix,disable-foo.nix}
+checkConfigOutput "true" config.enable ./disable-recursive/{main.nix,disable-bar.nix}
+checkConfigError 'The option .* defined in .* does not exist' config.enable ./disable-recursive/{main.nix,disable-foo.nix,disable-bar.nix}
+
 cat <<EOF
 ====== module tests ======
 $pass Pass

diff --git a/lib/tests/modules/disable-recursive/bar.nix b/lib/tests/modules/disable-recursive/bar.nix
@@ -0,0 +1,5 @@
+{
+  imports = [
+    ../declare-enable.nix
+  ];
+}
diff --git a/lib/tests/modules/disable-recursive/disable-bar.nix b/lib/tests/modules/disable-recursive/disable-bar.nix
@@ -0,0 +1,7 @@
+{
+
+  disabledModules = [
+    ./bar.nix
+  ];
+
+}
diff --git a/lib/tests/modules/disable-recursive/disable-foo.nix b/lib/tests/modules/disable-recursive/disable-foo.nix
@@ -0,0 +1,7 @@
+{
+
+  disabledModules = [
+    ./foo.nix
+  ];
+
+}
diff --git a/lib/tests/modules/disable-recursive/foo.nix b/lib/tests/modules/disable-recursive/foo.nix
@@ -0,0 +1,5 @@
+{
+  imports = [
+    ../declare-enable.nix
+  ];
+}
diff --git a/lib/tests/modules/disable-recursive/main.nix b/lib/tests/modules/disable-recursive/main.nix
@@ -0,0 +1,8 @@
+{
+  imports = [
+    ./foo.nix
+    ./bar.nix
+  ];
+
+  enable = true;
+}
diff --git a/nixos/doc/manual/development/replace-modules.xml b/nixos/doc/manual/development/replace-modules.xml
@@ -6,8 +6,8 @@
  <title>Replace Modules</title>
 
  <para>
-  Modules that are imported can also be disabled. The option declarations and
-  config implementation of a disabled module will be ignored, allowing another
+  Modules that are imported can also be disabled. The option declarations,
+  config implementation and the imports of a disabled module will be ignored, allowing another
   to take it's place. This can be used to import a set of modules from another
   channel while keeping the rest of the system on a stable release.
  </para>

diff --git a/nixos/modules/misc/documentation.nix b/nixos/modules/misc/documentation.nix
@@ -1,4 +1,4 @@
-{ config, lib, pkgs, baseModules, extraModules, modules, ... }:
+{ config, lib, pkgs, baseModules, extraModules, modules, modulesPath, ... }:
 
 with lib;
 
@@ -22,7 +22,10 @@ let
         scrubbedEval = evalModules {
           modules = [ { nixpkgs.localSystem = config.nixpkgs.localSystem; } ] ++ manualModules;
           args = (config._module.args) // { modules = [ ]; };
-          specialArgs = { pkgs = scrubDerivations "pkgs" pkgs; };
+          specialArgs = {
+            pkgs = scrubDerivations "pkgs" pkgs;
+            inherit modulesPath;
+          };
         };
         scrubDerivations = namePrefix: pkgSet: mapAttrs
           (name: value: