From 79703eef083d70046873dbb86f08e2ff08f58197 Mon Sep 17 00:00:00 2001
From: Robert Hensing <robert@roberthensing.nl>
Date: Mon, 10 Apr 2023 17:55:34 +0200
Subject: [PATCH] nixos,nixpkgs: Add module classes

This allows modules that declare their class to be checked.
While that's not most user modules, frameworks can take advantage
of this by setting declaring the module class for their users.
That way, the mistake of importing a module into the wrong hierarchy
can be reported more clearly in some cases.
---
 doc/doc-support/default.nix          | 5 ++++-
 nixos/lib/eval-cacheable-options.nix | 1 +
 nixos/lib/eval-config-minimal.nix    | 4 +++-
 nixos/lib/testing/default.nix        | 5 ++++-
 nixos/modules/misc/documentation.nix | 1 +
 pkgs/top-level/default.nix           | 1 +
 6 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/doc/doc-support/default.nix b/doc/doc-support/default.nix
index bea3e12a70b3..67195a4a58b0 100644
--- a/doc/doc-support/default.nix
+++ b/doc/doc-support/default.nix
@@ -45,7 +45,10 @@ let
   # NB: This file describes the Nixpkgs manual, which happens to use module
   #     docs infra originally developed for NixOS.
   optionsDoc = pkgs.nixosOptionsDoc {
-    inherit (pkgs.lib.evalModules { modules = [ ../../pkgs/top-level/config.nix ]; }) options;
+    inherit (pkgs.lib.evalModules {
+      modules = [ ../../pkgs/top-level/config.nix ];
+      specialArgs.class = "nixpkgsConfig";
+    }) options;
     documentType = "none";
     transformOptions = opt:
       opt // {
diff --git a/nixos/lib/eval-cacheable-options.nix b/nixos/lib/eval-cacheable-options.nix
index c3ba2ce66375..d26967ebe09b 100644
--- a/nixos/lib/eval-cacheable-options.nix
+++ b/nixos/lib/eval-cacheable-options.nix
@@ -33,6 +33,7 @@ let
     ];
     specialArgs = {
       inherit config pkgs utils;
+      class = "nixos";
     };
   };
   docs = import "${nixosPath}/doc/manual" {
diff --git a/nixos/lib/eval-config-minimal.nix b/nixos/lib/eval-config-minimal.nix
index d45b9ffd4261..7e28f4305127 100644
--- a/nixos/lib/eval-config-minimal.nix
+++ b/nixos/lib/eval-config-minimal.nix
@@ -40,7 +40,9 @@ let
     inherit prefix modules;
     specialArgs = {
       modulesPath = builtins.toString ../modules;
-    } // specialArgs;
+    } // specialArgs // {
+      class = "nixos";
+    };
   };
 
 in
diff --git a/nixos/lib/testing/default.nix b/nixos/lib/testing/default.nix
index 9d4f9dbc43d7..1bd6278ce684 100644
--- a/nixos/lib/testing/default.nix
+++ b/nixos/lib/testing/default.nix
@@ -1,7 +1,10 @@
 { lib }:
 let
 
-  evalTest = module: lib.evalModules { modules = testModules ++ [ module ]; };
+  evalTest = module: lib.evalModules {
+    modules = testModules ++ [ module ];
+    specialArgs.class = "nixosTest";
+  };
   runTest = module: (evalTest ({ config, ... }: { imports = [ module ]; result = config.test; })).config.result;
 
   testModules = [
diff --git a/nixos/modules/misc/documentation.nix b/nixos/modules/misc/documentation.nix
index e0c6af4abe10..1821dd866cb1 100644
--- a/nixos/modules/misc/documentation.nix
+++ b/nixos/modules/misc/documentation.nix
@@ -39,6 +39,7 @@ let
             _module.check = false;
           } ] ++ docModules.eager;
           specialArgs = specialArgs // {
+            class = "nixos";
             pkgs = scrubDerivations "pkgs" pkgs;
             # allow access to arbitrary options for eager modules, eg for getting
             # option types from lazy modules
diff --git a/pkgs/top-level/default.nix b/pkgs/top-level/default.nix
index b32aabc3a1fd..f54ce84aedad 100644
--- a/pkgs/top-level/default.nix
+++ b/pkgs/top-level/default.nix
@@ -82,6 +82,7 @@ in let
         config = config1;
       })
     ];
+    specialArgs.class = "nixpkgsConfig";
   };
 
   # take all the rest as-is