Enums that are not used as a type in XML can now suppress codegen intended for DataModel::Decode

src/app/common/templates/config-data.yaml

@@ -12,6 +12,19 @@ WeakEnums:
     - RadioFaultEnum
     - StepMode
 
+EnumsNotUsedInDataModelStruct:
+    # List of enums that are not used in a DataModel Struct. By adding an enum
+    # to this list you prevent incorrectly assuming from code that you are
+    # able to use kUnknownEnumValue safely. This happens for derivate clusters
+    # such as ModeBase where there are CommonTag, DerivedClusterTags, MfgTags.
+    - "DishwasherMode::ModeTag"
+    - "LaundryWasherMode::ModeTag"
+    - "RefrigeratorAndTemperatureControlledCabinetMode::ModeTag"
+    - "RvcRunMode::ModeTag"
+    - "RvcRunMode::StatusCode"
+    - "RvcCleanMode::ModeTag"
+    - "RvcCleanMode::StatusCode"
+
 CommandHandlerInterfaceOnlyClusters:
     # List of clusters that are implemented entirely with
     # CommandHandlerInterface and hence do not need generated command dispatch.

src/app/zap-templates/templates/app/cluster-enums-check.zapt

@@ -9,6 +9,7 @@ namespace app {
 namespace Clusters {
 {{#zcl_clusters}}
 {{#zcl_enums}}
+{{#unless (isInConfigList (concat (asUpperCamelCase ../name) "::" label) "EnumsNotUsedInDataModelStruct")}}
 static auto __attribute__((unused)) EnsureKnownEnumValue({{asUpperCamelCase ../name}}::{{asType label}} val)
 {
     using EnumType = {{asUpperCamelCase ../name}}::{{asType label}};
@@ -33,6 +34,7 @@ static auto __attribute__((unused)) EnsureKnownEnumValue({{asUpperCamelCase ../n
         return static_cast<EnumType>({{first_unused_enum_value mode="first_unused"}});
     }
 }
+{{/unless}}
 {{/zcl_enums}}
 
 {{/zcl_clusters}}

src/app/zap-templates/templates/app/cluster-enums.zapt

@@ -24,11 +24,18 @@ enum class {{asType label}} : {{asUnderlyingZclType name}} {
 {{#zcl_enum_items}}
 k{{asUpperCamelCase label}} = {{asHex value 2}},
 {{/zcl_enum_items}}
+{{#unless (isInConfigList (concat (asUpperCamelCase ../name) "::" label) "EnumsNotUsedInDataModelStruct")}}
 // All received enum values that are not listed above will be mapped
 // to kUnknownEnumValue. This is a helper enum value that should only
 // be used by code to process how it handles receiving and unknown
 // enum value. This specific should never be transmitted.
 kUnknownEnumValue = {{first_unused_enum_value mode="first_unused"}},
+{{else}}
+// kUnknownEnumValue intentionally not defined. This enum is not used
+// in a DataModel struct, likely because it is a part of a derivative
+// cluster. As a result having kUnknownEnumValue in this enum is error
+// prone, and was removed.
+{{/unless}}
 };
 {{#if (isInConfigList label "WeakEnums")}}
 #else // CHIP_USE_ENUM_CLASS_FOR_IM_ENUM

src/controller/python/templates/python-cluster-Objects-py.zapt

@@ -54,11 +54,18 @@ class {{asUpperCamelCase name}}(Cluster):
 {{#zcl_enum_items}}
             k{{asUpperCamelCase label}} = {{asHex value 2}}
 {{/zcl_enum_items}}
+{{#unless (isInConfigList (concat (asUpperCamelCase ../name) "::" label) "EnumsNotUsedInDataModelStruct")}}
             # All received enum values that are not listed above will be mapped
             # to kUnknownEnumValue. This is a helper enum value that should only
             # be used by code to process how it handles receiving and unknown
             # enum value. This specific should never be transmitted.
             kUnknownEnumValue = {{first_unused_enum_value mode="first_unused"}},
+{{else}}
+            # kUnknownEnumValue intentionally not defined. This enum is not used
+            # in a DataModel struct, likely because it is a part of a derivative
+            # cluster. As a result having kUnknownEnumValue in this enum is error
+            # prone, and was removed.
+{{/unless}}
 
 {{#last}}
 {{/last}}

src/controller/python/templates/templates.json

@@ -8,6 +8,9 @@
         "templates/chip/helper.js",
         "controller/python/templates/helper.js"
     ],
+    "resources": {
+        "config-data": "../../../../src/app/common/templates/config-data.yaml"
+    },
     "override": "../../../../src/app/zap-templates/common/override.js",
     "partials": [
         {