From 91f939a391032db72220e4be715b888d0f8db287 Mon Sep 17 00:00:00 2001
From: Jose Ignacio Marquez Damian <marquezj@ess.eu>
Date: Fri, 18 Nov 2022 18:26:31 +0100
Subject: [PATCH] Add flag for NCrystal

---
 include/openmc/settings.h               | 2 ++
 openmc/lib/__init__.py                  | 3 +++
 src/settings.cpp                        | 7 +++++++
 tests/regression_tests/ncrystal/test.py | 7 +++++++
 4 files changed, 19 insertions(+)

diff --git a/include/openmc/settings.h b/include/openmc/settings.h
index 9bb447005c..b01c75d45c 100644
--- a/include/openmc/settings.h
+++ b/include/openmc/settings.h
@@ -20,6 +20,8 @@ namespace openmc {
 // Global variable declarations
 //==============================================================================
 
+extern "C" const bool NCRYSTAL_ENABLED;
+
 namespace settings {
 
 // Boolean flags
diff --git a/openmc/lib/__init__.py b/openmc/lib/__init__.py
index c14b0d9c28..55e2ec11b3 100644
--- a/openmc/lib/__init__.py
+++ b/openmc/lib/__init__.py
@@ -42,6 +42,9 @@ else:
 def _dagmc_enabled():
     return c_bool.in_dll(_dll, "DAGMC_ENABLED").value
 
+def _ncrystal_enabled():
+    return c_bool.in_dll(_dll, "NCRYSTAL_ENABLED").value
+
 def _coord_levels():
     return c_int.in_dll(_dll, "n_coord_levels").value
 
diff --git a/src/settings.cpp b/src/settings.cpp
index 87c24eedd3..be7228d681 100644
--- a/src/settings.cpp
+++ b/src/settings.cpp
@@ -36,6 +36,13 @@ namespace openmc {
 // Global variables
 //==============================================================================
 
+#ifdef NCRYSTAL
+const bool NCRYSTAL_ENABLED = true;
+#else
+const bool NCRYSTAL_ENABLED = false;
+#endif
+
+
 namespace settings {
 
 // Default values for boolean flags
diff --git a/tests/regression_tests/ncrystal/test.py b/tests/regression_tests/ncrystal/test.py
index 51a0f07b72..0a47d634df 100644
--- a/tests/regression_tests/ncrystal/test.py
+++ b/tests/regression_tests/ncrystal/test.py
@@ -1,7 +1,14 @@
 import numpy as np
 import openmc
+import openmc.lib
+import pytest
+
 from tests.testing_harness import PyAPITestHarness
 
+pytestmark = pytest.mark.skipif(
+    not openmc.lib._ncrystal_enabled(),
+    reason="NCrystal materials are not enabled.")
+
 def compute_angular_distribution(cfg, E0, N):
     """Return a openmc.model.Model() object for a monoenergetic pencil
      beam hitting a 1 mm sphere filled with the material defined by