From cb4f96545ed26fa5d4db5611491c8d18f5ac584c Mon Sep 17 00:00:00 2001
From: Matti Kortelainen <matti.kortelainen@cern.ch>
Date: Fri, 29 Aug 2025 21:44:24 +0200
Subject: [PATCH] List PortableTestHost{Collection,Object} nested type aliases
 before their aliased types in classes_def.xml

In ROOT presently the type alias gets listed in the rootmap file only
if the alias is requested before the real type. Having the type alias
in the rootmap file is necessary to avoid header parsing for the
execution of the read rules that use the type alias names.
---
 .../PortableTestObjects/src/classes_def.xml   | 22 +++++++++++++------
 1 file changed, 15 insertions(+), 7 deletions(-)

diff --git a/DataFormats/PortableTestObjects/src/classes_def.xml b/DataFormats/PortableTestObjects/src/classes_def.xml
index caafb7f08ea21..6a57029fdcbd1 100644
--- a/DataFormats/PortableTestObjects/src/classes_def.xml
+++ b/DataFormats/PortableTestObjects/src/classes_def.xml
@@ -1,15 +1,29 @@
 <lcgdict>
   <class name="portabletest::TestHostCollection"/>
+  <!-- portabletest::TestHostCollection::Layout alias must be listed before the aliased-to type -->
+  <class name="portabletest::TestHostCollection::Layout"/>
   <class name="edm::Wrapper<portabletest::TestHostCollection>" splitLevel="0"/>
 
-  <class name="portabletest::TestStruct"/>
   <class name="portabletest::TestHostObject"/>
+  <!-- portabletest::TestHostObject::Product alias must be listed before the aliased-to type -->
+  <class name="portabletest::TestHostObject::Product"/>
   <class name="edm::Wrapper<portabletest::TestHostObject>"/>
+  <class name="portabletest::TestStruct"/>
 
   <class name="portabletest::TestSoALayout<128,false>"/>
   <class name="portabletest::TestSoALayout2<128,false>"/>
   <class name="portabletest::TestSoALayout3<128,false>"/>
 
+  <!-- Collection declaration for dictionary -->
+  <class name="portabletest::TestHostMultiCollection2"/>
+  <!-- portabletest::TestHostObject::Implementation alias must be listed before the aliased-to type -->
+  <class name="portabletest::TestHostMultiCollection2::Implementation"/>
+
+  <!-- Collection declaration for dictionary -->
+  <class name="portabletest::TestHostMultiCollection3"/>
+  <!-- portabletest::TestHostObject::Implementation alias must be listed before the aliased-to type -->
+  <class name="portabletest::TestHostMultiCollection3::Implementation"/>
+
   <!-- Recursive templates (with no data) ensuring we have one CollectionLeaf<index, type> for each layout in the collection -->
   <class name="portablecollection::CollectionImpl<0, portabletest::TestSoALayout<128, false>, portabletest::TestSoALayout2<128, false>>"/>
   <class name="portablecollection::CollectionImpl<1, portabletest::TestSoALayout2<128, false>>"/>
@@ -18,9 +32,6 @@
   <class name="portablecollection::CollectionLeaf<0, portabletest::TestSoALayout<128, false>>"/>
   <class name="portablecollection::CollectionLeaf<1, portabletest::TestSoALayout2<128, false>>"/>
 
-  <!-- Collection declaration for dictionary -->
-  <class name="portabletest::TestHostMultiCollection2"/>
-
   <class name="edm::Wrapper<portabletest::TestHostMultiCollection2>" splitLevel="0"/>
 
   <!-- Recursive templates (with no data) ensuring we have one CollectionLeaf<index, type> for each layout in the collection -->
@@ -35,9 +46,6 @@
   -->
   <class name="portablecollection::CollectionLeaf<2, portabletest::TestSoALayout3<128, false>>"/>
 
-  <!-- Collection declaration for dictionary -->
-  <class name="portabletest::TestHostMultiCollection3"/>
-
   <class name="edm::Wrapper<portabletest::TestHostMultiCollection3>" splitLevel="0"/>
 
   <class name="portabletest::TestProductWithPtr<alpaka_common::DevHost>"/>