Implement class_id workaround for all methods

src/pcms/field/layout/omega_h_entity.cpp

@@ -54,7 +54,9 @@ OmegaHEntityLayout::OmegaHEntityLayout(Omega_h::Mesh& mesh, int entity_dim,
                                        int num_components,
                                        CoordinateSystem coordinate_system,
                                        std::string global_id_name)
-  : dimension_(mesh.dim()),
+  // dimension_ is the first member, so this runs before the class_ids_/
+  // class_dims_ initializers below read the mesh's classification tags.
+  : dimension_((EnsureClassification(mesh), mesh.dim())),
     entity_dim_(entity_dim),
     num_components_(num_components),
     num_global_dof_holder_(mesh.nglobal_ents(entity_dim)),

src/pcms/field/layout/omega_h_lagrange.cpp

@@ -3,7 +3,6 @@
 #include "pcms/utility/mesh_geometry.h"
 #include "pcms/utility/omega_h_array_utils.h"
 #include "pcms/utility/profile.h"
-#include <Omega_h_class.hpp>
 #include <stdexcept>
 
 namespace pcms
@@ -49,35 +48,6 @@ Omega_h::Write<Omega_h::GO> BuildGids(Omega_h::Mesh& mesh, int entity_dim,
   return gids;
 }
 
-// Some meshes (e.g. certain XGC meshes) are stored without any geometric
-// classification (no class_id/class_dim tags). The layout and its
-// discretization read these tags on every mesh dimension, so derive a default
-// classification when it is missing. classify_elements +
-// finalize_classification populate a geometrically meaningful class_dim on all
-// dimensions but do not create class_id (that normally comes from a geometric
-// model we don't have here), so fill any missing class_id with 0.
-// Classification is only consulted for coupling DOF matching
-// (field_exchange_planner); standalone field transfer never reads it, so a
-// default id is sufficient to keep such meshes usable.
-void EnsureClassification(Omega_h::Mesh& mesh)
-{
-  if (mesh.has_tag(mesh.dim(), "class_id") &&
-      mesh.has_tag(mesh.dim(), "class_dim")) {
-    return;
-  }
-  if (!mesh.has_tag(mesh.dim(), "class_dim")) {
-    Omega_h::classify_elements(&mesh);
-    Omega_h::finalize_classification(&mesh);
-  }
-  for (int d = 0; d <= mesh.dim(); ++d) {
-    if (!mesh.has_tag(d, "class_id")) {
-      mesh.add_tag<Omega_h::ClassId>(
-        d, "class_id", 1,
-        Omega_h::Read<Omega_h::ClassId>(mesh.nents(d), 0, "class_id"));
-    }
-  }
-}
-
 Kokkos::View<bool*, DeviceMemorySpace> BuildOwned(Omega_h::Mesh& mesh,
                                                   int entity_dim)
 {

src/pcms/utility/mesh_geometry.h

@@ -2,6 +2,7 @@
 #define PCMS_UTILITY_MESH_GEOMETRY_H
 
 #include <Omega_h_array.hpp>
+#include <Omega_h_class.hpp>
 #include <Omega_h_for.hpp>
 #include <Omega_h_mesh.hpp>
 
@@ -93,6 +94,35 @@ inline Omega_h::Reals get_entity_centroids(Omega_h::Mesh& mesh,
   return Omega_h::Reals(centroids);
 }
 
+// Some meshes (e.g. certain XGC meshes) are stored without any geometric
+// classification (no class_id/class_dim tags). Layouts read these tags on
+// every mesh dimension, so derive a default classification when it is
+// missing. classify_elements + finalize_classification populate a
+// geometrically meaningful class_dim on all dimensions but do not create
+// class_id (that normally comes from a geometric model we don't have here),
+// so fill any missing class_id with 0.
+// Classification is only consulted for coupling DOF matching
+// (field_exchange_planner); standalone field transfer never reads it, so a
+// default id is sufficient to keep such meshes usable.
+inline void EnsureClassification(Omega_h::Mesh& mesh)
+{
+  if (mesh.has_tag(mesh.dim(), "class_id") &&
+      mesh.has_tag(mesh.dim(), "class_dim")) {
+    return;
+  }
+  if (!mesh.has_tag(mesh.dim(), "class_dim")) {
+    Omega_h::classify_elements(&mesh);
+    Omega_h::finalize_classification(&mesh);
+  }
+  for (int d = 0; d <= mesh.dim(); ++d) {
+    if (!mesh.has_tag(d, "class_id")) {
+      mesh.add_tag<Omega_h::ClassId>(
+        d, "class_id", 1,
+        Omega_h::Read<Omega_h::ClassId>(mesh.nents(d), 0, "class_id"));
+    }
+  }
+}
+
 } // namespace pcms
 
 #endif // PCMS_UTILITY_MESH_GEOMETRY_H