Recursive type deprecation

lib/modules.nix

@@ -515,11 +515,20 @@ rec {
       # yield a value computed from the definitions
       value = if opt ? apply then opt.apply res.mergedValue else res.mergedValue;
 
-      warnDeprecation =
-        warnIf (opt.type.deprecationMessage != null)
-          "The type `types.${opt.type.name}' of option `${showOption loc}' defined in ${showFiles opt.declarations} is deprecated. ${opt.type.deprecationMessage}";
+      # Issue deprecation warnings recursively over all nested types of the
+      # given type. But don't recurse if a type with the same name was already
+      # visited before in order to prevent infinite recursion. So this only
+      # warns once per type name.
+      # Returns the new set of visited type names
+      recursiveWarn = visited: type:
+        let
+          maybeWarn = warnIf (type.deprecationMessage != null)
+            "The type `types.${type.name}' of option `${showOption loc}' defined in ${showFiles opt.declarations} is deprecated. ${type.deprecationMessage}";
+        in
+          if visited ? ${type.name} then visited
+          else lib.foldl' recursiveWarn (maybeWarn visited // { ${type.name} = null; }) (lib.attrValues type.nestedTypes);
 
-    in warnDeprecation opt //
+    in builtins.seq (recursiveWarn {} opt.type) opt //
       { value = builtins.addErrorContext "while evaluating the option `${showOption loc}':" value;
         inherit (res.defsFinal') highestPrio;
         definitions = map (def: def.value) res.defsFinal;

lib/tests/modules.sh

@@ -175,6 +175,9 @@ checkConfigOutput "true" config.submodule.config ./declare-submoduleWith-noshort
 ## submoduleWith should merge all modules in one swoop
 checkConfigOutput "true" config.submodule.inner ./declare-submoduleWith-modules.nix
 checkConfigOutput "true" config.submodule.outer ./declare-submoduleWith-modules.nix
+# Should also be able to evaluate the type name (which evaluates freeformType,
+# which evaluates all the modules defined by the type)
+checkConfigOutput "submodule" options.submodule.type.description ./declare-submoduleWith-modules.nix
 
 ## Paths should be allowed as values and work as expected
 checkConfigOutput "true" config.submodule.enable ./declare-submoduleWith-path.nix
@@ -269,6 +272,12 @@ checkConfigError 'A definition for option .fun.\[function body\]. is not of type
 checkConfigOutput "b a" config.result ./functionTo/list-order.nix
 checkConfigOutput "a c" config.result ./functionTo/merging-attrs.nix
 
+## Type deprecation
+checkConfigError 'The type `types.simple'\'' of option `simple'\'' defined in .* is deprecated. simple shall not be used' config.simple ./type-deprecation.nix
+checkConfigError 'The type `types.infinite'\'' of option `infinite'\'' defined in .* is deprecated. infinite shall not be used' config.infinite ./type-deprecation.nix
+checkConfigError 'The type `types.left'\'' of option `nested'\'' defined in .* is deprecated. left shall not be used' config.nested ./type-deprecation.nix
+checkConfigError 'The type `types.right'\'' of option `nested'\'' defined in .* is deprecated. right shall not be used' config.nested ./type-deprecation.nix
+
 cat <<EOF
 ====== module tests ======
 $pass Pass

lib/tests/modules/declare-submoduleWith-modules.nix

@@ -8,9 +8,6 @@
             default = false;
           };
         }
-        {
-          outer = true;
-        }
       ];
     };
     default = {};
@@ -25,6 +22,7 @@
     })
     {
       inner = true;
+      outer = true;
     }
   ];
 }

lib/tests/modules/type-deprecation.nix

@@ -0,0 +1,39 @@
+{ lib, ... }: {
+
+  options.simple = lib.mkOption {
+    type = lib.mkOptionType {
+      name = "simple";
+      deprecationMessage = "simple shall not be used";
+    };
+    default = throw "";
+  };
+
+  options.infinite = lib.mkOption {
+    type =
+      let
+        t = lib.mkOptionType {
+          name = "infinite";
+          deprecationMessage = "infinite shall not be used";
+        };
+        r = lib.types.either t (lib.types.attrsOf r);
+      in r;
+    default = throw "";
+  };
+
+  options.nested = lib.mkOption {
+    type =
+      let
+        left = lib.mkOptionType {
+          name = "left";
+          deprecationMessage = "left shall not be used";
+        };
+        right = lib.mkOptionType {
+          name = "right";
+          deprecationMessage = "right shall not be used";
+        };
+      in lib.types.either left right;
+
+    default = throw "";
+  };
+
+}

lib/types.nix

@@ -147,9 +147,13 @@ rec {
     , # The deprecation message to display when this type is used by an option
       # If null, the type isn't deprecated
       deprecationMessage ? null
+    , # The types that occur in the definition of this type. This is used to
+      # issue deprecation warnings recursively. Can also be used to reuse
+      # nested types
+      nestedTypes ? {}
     }:
     { _type = "option-type";
-      inherit name check merge emptyValue getSubOptions getSubModules substSubModules typeMerge functor deprecationMessage;
+      inherit name check merge emptyValue getSubOptions getSubModules substSubModules typeMerge functor deprecationMessage nestedTypes;
       description = if description == null then name else description;
     };
 
@@ -365,6 +369,7 @@ rec {
       getSubModules = elemType.getSubModules;
       substSubModules = m: listOf (elemType.substSubModules m);
       functor = (defaultFunctor name) // { wrapped = elemType; };
+      nestedTypes.elemType = elemType;
     };
 
     nonEmptyListOf = elemType:
@@ -389,6 +394,7 @@ rec {
       getSubModules = elemType.getSubModules;
       substSubModules = m: attrsOf (elemType.substSubModules m);
       functor = (defaultFunctor name) // { wrapped = elemType; };
+      nestedTypes.elemType = elemType;
     };
 
     # A version of attrsOf that's lazy in its values at the expense of
@@ -413,6 +419,7 @@ rec {
       getSubModules = elemType.getSubModules;
       substSubModules = m: lazyAttrsOf (elemType.substSubModules m);
       functor = (defaultFunctor name) // { wrapped = elemType; };
+      nestedTypes.elemType = elemType;
     };
 
     # TODO: drop this in the future:
@@ -421,6 +428,7 @@ rec {
       deprecationMessage = "Mixing lists with attribute values is no longer"
         + " possible; please use `types.attrsOf` instead. See"
         + " https://github.com/NixOS/nixpkgs/issues/1800 for the motivation.";
+      nestedTypes.elemType = elemType;
     };
 
     # Value of given type but with no merging (i.e. `uniq list`s are not concatenated).
@@ -433,6 +441,7 @@ rec {
       getSubModules = elemType.getSubModules;
       substSubModules = m: uniq (elemType.substSubModules m);
       functor = (defaultFunctor name) // { wrapped = elemType; };
+      nestedTypes.elemType = elemType;
     };
 
     # Null or value of ...
@@ -451,6 +460,7 @@ rec {
       getSubModules = elemType.getSubModules;
       substSubModules = m: nullOr (elemType.substSubModules m);
       functor = (defaultFunctor name) // { wrapped = elemType; };
+      nestedTypes.elemType = elemType;
     };
 
     functionTo = elemType: mkOptionType {
@@ -535,6 +545,9 @@ rec {
         substSubModules = m: submoduleWith (attrs // {
           modules = m;
         });
+        nestedTypes = lib.optionalAttrs (freeformType != null) {
+          freeformType = freeformType;
+        };
         functor = defaultFunctor name // {
           type = types.submoduleWith;
           payload = {
@@ -596,6 +609,8 @@ rec {
            then functor.type mt1 mt2
            else null;
       functor = (defaultFunctor name) // { wrapped = [ t1 t2 ]; };
+      nestedTypes.left = t1;
+      nestedTypes.right = t2;
     };
 
     # Any of the types in the given list
@@ -627,6 +642,8 @@ rec {
         substSubModules = m: coercedTo coercedType coerceFunc (finalType.substSubModules m);
         typeMerge = t1: t2: null;
         functor = (defaultFunctor name) // { wrapped = finalType; };
+        nestedTypes.coercedType = coercedType;
+        nestedTypes.finalType = finalType;
       };
 
     # Obsolete alternative to configOf.  It takes its option