Make use of ZAP's new support for specifying the parent of an endpoint.

Specific changes:

* Remove unused FIXED_NETWORKS bit from endpoint_config.h.
* Add FIXED_PARENT_ENDPOINTS which lists the parents of each fixed endpoint.
* Condition the fixed endpoint initialization code on FIXED_ENDPOINT_COUNT > 0
  and remove some Darwin hackery that was needed because it was not thus
  conditioned.
* Add initialization of parentEndpointId for fixed endpoints from
  FIXED_PARENT_ENDPOINTS.

At the moment FIXED_PARENT_ENDPOINTS uses 0 to mean "no parent specified", but I
am hoping the ZAP folks will fix things so that we can just have
kInvalidEndpointId in there and the code in emberAfEndpointConfigure can become
simpler/smaller.

Author: bzbarsky-apple

src/app/util/attribute-storage.cpp

@@ -183,10 +183,15 @@ void emberAfEndpointConfigure()
     static_assert(FIXED_ENDPOINT_COUNT <= std::numeric_limits<decltype(ep)>::max(),
                   "FIXED_ENDPOINT_COUNT must not exceed the size of the endpoint data type");
 
-    uint16_t fixedEndpoints[]             = FIXED_ENDPOINT_ARRAY;
-    uint16_t fixedDeviceTypeListLengths[] = FIXED_DEVICE_TYPE_LENGTHS;
-    uint16_t fixedDeviceTypeListOffsets[] = FIXED_DEVICE_TYPE_OFFSETS;
-    uint8_t fixedEmberAfEndpointTypes[]   = FIXED_ENDPOINT_TYPES;
+    emberEndpointCount = FIXED_ENDPOINT_COUNT;
+
+#if FIXED_ENDPOINT_COUNT > 0
+
+    constexpr uint16_t fixedEndpoints[]             = FIXED_ENDPOINT_ARRAY;
+    constexpr uint16_t fixedDeviceTypeListLengths[] = FIXED_DEVICE_TYPE_LENGTHS;
+    constexpr uint16_t fixedDeviceTypeListOffsets[] = FIXED_DEVICE_TYPE_OFFSETS;
+    constexpr uint8_t fixedEmberAfEndpointTypes[]   = FIXED_ENDPOINT_TYPES;
+    constexpr EndpointId fixedParentEndpoints[]     = FIXED_PARENT_ENDPOINTS;
 
 #if ZAP_FIXED_ENDPOINT_DATA_VERSION_COUNT > 0
     // Initialize our data version storage.  If
@@ -201,7 +206,6 @@ void emberAfEndpointConfigure()
     }
 #endif // ZAP_FIXED_ENDPOINT_DATA_VERSION_COUNT > 0
 
-    emberEndpointCount                = FIXED_ENDPOINT_COUNT;
     DataVersion * currentDataVersions = fixedEndpointDataVersions;
     for (ep = 0; ep < FIXED_ENDPOINT_COUNT; ep++)
     {
@@ -210,6 +214,14 @@ void emberAfEndpointConfigure()
             Span<const EmberAfDeviceType>(&fixedDeviceTypeList[fixedDeviceTypeListOffsets[ep]], fixedDeviceTypeListLengths[ep]);
         emAfEndpoints[ep].endpointType = &generatedEmberAfEndpointTypes[fixedEmberAfEndpointTypes[ep]];
         emAfEndpoints[ep].dataVersions = currentDataVersions;
+        if (fixedParentEndpoints[ep] == 0)
+        {
+            emAfEndpoints[ep].parentEndpointId = kInvalidEndpointId;
+        }
+        else
+        {
+            emAfEndpoints[ep].parentEndpointId = fixedParentEndpoints[ep];
+        }
 
         emAfEndpoints[ep].bitmask.Set(EmberAfEndpointOptions::isEnabled);
         emAfEndpoints[ep].bitmask.Set(EmberAfEndpointOptions::isFlatComposition);
@@ -219,6 +231,8 @@ void emberAfEndpointConfigure()
         currentDataVersions += emberAfClusterCountByIndex(ep, /* server = */ true);
     }
 
+#endif // FIXED_ENDPOINT_COUNT > 0
+
 #if CHIP_DEVICE_CONFIG_DYNAMIC_ENDPOINT_COUNT
     if (MAX_ENDPOINT_COUNT > FIXED_ENDPOINT_COUNT)
     {

src/app/zap-templates/templates/app/endpoint_config.zapt

@@ -95,7 +95,7 @@ static_assert(ATTRIBUTE_LARGEST <= CHIP_CONFIG_MAX_ATTRIBUTE_STORE_ELEMENT_SIZE,
 // Array of endpoint types supported on each endpoint
 #define FIXED_ENDPOINT_TYPES {{endpoint_fixed_endpoint_type_array}}
 
-// Array of networks supported on each endpoint
-#define FIXED_NETWORKS {{endpoint_fixed_network_array}}
+// Array of parent endpoints for each endpoint
+#define FIXED_PARENT_ENDPOINTS {{endpoint_fixed_parent_id_array}}
 
 {{/endpoint_config}}