Query optional build features through the C API

docs/source/pythonapi/capi.rst

@@ -16,6 +16,7 @@ Functions
    current_batch
    export_properties
    export_weight_windows
+   feature_enabled
    finalize
    find_cell
    find_material

include/openmc/capi.h

@@ -352,6 +352,15 @@ int openmc_properties_export(const char* filename);
 // \return Error code
 int openmc_properties_import(const char* filename);
 
+//! Get whether an optional build feature is enabled.
+//!
+//! Supported feature names are ``dagmc``, ``libmesh``, ``strict_fp``, and
+//! ``uwuw``.
+//! \param feature Name of the feature to query
+//! \param enabled Whether the feature is enabled
+//! \return Error code
+int openmc_get_feature_enabled(const char* feature, bool* enabled);
+
 // Error codes
 extern int OPENMC_E_UNASSIGNED;
 extern int OPENMC_E_ALLOCATE;

include/openmc/dagmc.h

@@ -1,11 +1,6 @@
 #ifndef OPENMC_DAGMC_H
 #define OPENMC_DAGMC_H
 
-namespace openmc {
-extern "C" const bool DAGMC_ENABLED;
-extern "C" const bool UWUW_ENABLED;
-} // namespace openmc
-
 // always include the XML interface header
 #include "openmc/xml_interface.h"
 

include/openmc/mesh.h

@@ -51,8 +51,6 @@ enum class ElementType { UNSUPPORTED = -1, LINEAR_TET, LINEAR_HEX };
 // Global variables
 //==============================================================================
 
-extern "C" const bool LIBMESH_ENABLED;
-
 class Mesh;
 
 namespace model {

include/openmc/output.h

@@ -10,8 +10,6 @@
 
 namespace openmc {
 
-extern "C" const bool STRICT_FP_ENABLED;
-
 //! \brief Display the main title banner as well as information about the
 //! program developers, version, and date/time which the problem was run.
 void title();

openmc/lib/__init__.py

@@ -12,7 +12,7 @@
 
 """
 
-from ctypes import CDLL, c_bool, c_int
+from ctypes import CDLL, byref, c_bool, c_char_p, c_int, POINTER
 import importlib.resources
 import os
 import sys
@@ -36,21 +36,38 @@
     from unittest.mock import Mock
     _dll = Mock()
 
+from .error import _error_handler
 
-def _dagmc_enabled():
-    return c_bool.in_dll(_dll, "DAGMC_ENABLED").value
+_dll.openmc_get_feature_enabled.argtypes = [c_char_p, POINTER(c_bool)]
+_dll.openmc_get_feature_enabled.restype = c_int
+_dll.openmc_get_feature_enabled.errcheck = _error_handler
 
-def _coord_levels():
-    return c_int.in_dll(_dll, "n_coord_levels").value
+def feature_enabled(feature: str) -> bool:
+    """Return whether OpenMC was built with an optional feature.
+
+    Parameters
+    ----------
+    feature : {'dagmc', 'libmesh', 'strict_fp', 'uwuw'}
+        Feature to query.
+
+    Returns
+    -------
+    bool
+        Whether the feature is enabled.
 
-def _libmesh_enabled():
-    return c_bool.in_dll(_dll, "LIBMESH_ENABLED").value
+    Raises
+    ------
+    InvalidArgumentError
+        If *feature* is not recognized.
 
-def _uwuw_enabled():
-    return c_bool.in_dll(_dll, "UWUW_ENABLED").value
+    """
+    enabled = c_bool()
+    _dll.openmc_get_feature_enabled(feature.encode(), byref(enabled))
+    return enabled.value
 
-def _strict_fp_enabled():
-    return c_bool.in_dll(_dll, "STRICT_FP_ENABLED").value
+
+def _coord_levels():
+    return c_int.in_dll(_dll, "n_coord_levels").value
 
 
 from .error import *

src/dagmc.cpp

@@ -25,22 +25,6 @@
 #include <sstream>
 #include <string>
 
-namespace openmc {
-
-#ifdef OPENMC_DAGMC_ENABLED
-const bool DAGMC_ENABLED = true;
-#else
-const bool DAGMC_ENABLED = false;
-#endif
-
-#ifdef OPENMC_UWUW_ENABLED
-const bool UWUW_ENABLED = true;
-#else
-const bool UWUW_ENABLED = false;
-#endif
-
-} // namespace openmc
-
 #ifdef OPENMC_DAGMC_ENABLED
 
 namespace openmc {

src/mesh.cpp

@@ -61,12 +61,6 @@ namespace openmc {
 // Global variables
 //==============================================================================
 
-#ifdef OPENMC_LIBMESH_ENABLED
-const bool LIBMESH_ENABLED = true;
-#else
-const bool LIBMESH_ENABLED = false;
-#endif
-
 // Value used to indicate an empty slot in the hash table. We use -2 because
 // the value -1 is used to indicate a void material.
 constexpr int32_t EMPTY = -2;

src/output.cpp

@@ -44,11 +44,44 @@
 
 namespace openmc {
 
+extern "C" int openmc_get_feature_enabled(const char* feature, bool* enabled)
+{
+  if (!feature || !enabled) {
+    set_errmsg("Feature name and output pointer must not be null.");
+    return OPENMC_E_INVALID_ARGUMENT;
+  }
+
+  if (strcmp(feature, "dagmc") == 0) {
+#ifdef OPENMC_DAGMC_ENABLED
+    *enabled = true;
+#else
+    *enabled = false;
+#endif
+  } else if (strcmp(feature, "libmesh") == 0) {
+#ifdef OPENMC_LIBMESH_ENABLED
+    *enabled = true;
+#else
+    *enabled = false;
+#endif
+  } else if (strcmp(feature, "strict_fp") == 0) {
 #ifdef OPENMC_ENABLE_STRICT_FP
-const bool STRICT_FP_ENABLED = true;
+    *enabled = true;
+#else
+    *enabled = false;
+#endif
+  } else if (strcmp(feature, "uwuw") == 0) {
+#ifdef OPENMC_UWUW_ENABLED
+    *enabled = true;
 #else
-const bool STRICT_FP_ENABLED = false;
+    *enabled = false;
 #endif
+  } else {
+    set_errmsg(fmt::format("Unknown build feature '{}'.", feature));
+    return OPENMC_E_INVALID_ARGUMENT;
+  }
+
+  return 0;
+}
 
 //==============================================================================
 

tests/conftest.py

@@ -16,7 +16,7 @@
 
 def _check_build_environment():
     """Check STRICT_FP and cross section data, collecting any warnings."""
-    if not openmc.lib._strict_fp_enabled():
+    if not openmc.lib.feature_enabled('strict_fp'):
         _environment_warnings.append(
             "OpenMC was NOT built with -DOPENMC_ENABLE_STRICT_FP=on. "
             "Regression test results may not match reference values due to "

tests/regression_tests/dagmc/external/test.py

@@ -12,7 +12,7 @@
 from tests.testing_harness import PyAPITestHarness
 
 pytestmark = pytest.mark.skipif(
-    not openmc.lib._dagmc_enabled(),
+    not openmc.lib.feature_enabled('dagmc'),
     reason="DAGMC is not enabled.")
 
 # Test that an external DAGMC instance can be passed in through the C API

tests/regression_tests/dagmc/legacy/test.py

@@ -10,7 +10,7 @@
 from tests.testing_harness import PyAPITestHarness, config
 
 pytestmark = pytest.mark.skipif(
-    not openmc.lib._dagmc_enabled(),
+    not openmc.lib.feature_enabled('dagmc'),
     reason="DAGMC CAD geometry is not enabled.")
 
 @pytest.fixture

tests/regression_tests/dagmc/refl/test.py

@@ -6,7 +6,7 @@
 from tests.testing_harness import PyAPITestHarness
 
 pytestmark = pytest.mark.skipif(
-    not openmc.lib._uwuw_enabled(),
+    not openmc.lib.feature_enabled('uwuw'),
     reason="UWUW is not enabled.")
 
 class UWUWTest(PyAPITestHarness):

tests/regression_tests/dagmc/universes/test.py

@@ -7,7 +7,7 @@
 from tests.testing_harness import PyAPITestHarness
 
 pytestmark = pytest.mark.skipif(
-    not openmc.lib._dagmc_enabled(),
+    not openmc.lib.feature_enabled('dagmc'),
     reason="DAGMC CAD geometry is not enabled.")
 
 

tests/regression_tests/dagmc/uwuw/test.py

@@ -6,7 +6,7 @@
 from tests.testing_harness import PyAPITestHarness
 
 pytestmark = pytest.mark.skipif(
-    not openmc.lib._uwuw_enabled(),
+    not openmc.lib.feature_enabled('uwuw'),
     reason="UWUW is not enabled.")
 
 class UWUWTest(PyAPITestHarness):

tests/regression_tests/external_moab/test.py

@@ -16,7 +16,7 @@
 from tests.testing_harness import PyAPITestHarness
 
 pytestmark = pytest.mark.skipif(
-    not openmc.lib._dagmc_enabled(),
+    not openmc.lib.feature_enabled('dagmc'),
     reason="DAGMC is not enabled.")
 
 TETS_PER_VOXEL = 12

tests/regression_tests/surface_source_write/test.py

@@ -1075,7 +1075,7 @@ def model_dagmc_2():
 
 
 @pytest.mark.skipif(
-    not openmc.lib._dagmc_enabled(), reason="DAGMC CAD geometry is not enabled."
+    not openmc.lib.feature_enabled('dagmc'), reason="DAGMC CAD geometry is not enabled."
 )
 @pytest.mark.skipif(config["event"] is True, reason="Results from history-based mode.")
 @pytest.mark.parametrize(

tests/regression_tests/unstructured_mesh/test.py

@@ -255,10 +255,10 @@ def model():
 @pytest.mark.parametrize("test_opts", test_cases)
 def test_unstructured_mesh_tets(model, test_opts):
     # skip the test if the library is not enabled
-    if test_opts['library'] == 'moab' and not openmc.lib._dagmc_enabled():
+    if test_opts['library'] == 'moab' and not openmc.lib.feature_enabled('dagmc'):
         pytest.skip("DAGMC (and MOAB) mesh not enabled in this build.")
 
-    if test_opts['library'] == 'libmesh' and not openmc.lib._libmesh_enabled():
+    if test_opts['library'] == 'libmesh' and not openmc.lib.feature_enabled('libmesh'):
         pytest.skip("LibMesh is not enabled in this build.")
 
     # skip the tracklength test for libmesh
@@ -302,7 +302,7 @@ def test_unstructured_mesh_tets(model, test_opts):
     harness.main()
 
 
-@pytest.mark.skipif(not openmc.lib._libmesh_enabled(),
+@pytest.mark.skipif(not openmc.lib.feature_enabled('libmesh'),
                     reason='LibMesh is not enabled in this build.')
 def test_unstructured_mesh_hexes(model):
     regular_mesh_tally = model.tallies[0]

tests/unit_tests/dagmc/test.py

@@ -10,7 +10,7 @@
 from tests import cdtemp
 
 pytestmark = pytest.mark.skipif(
-    not openmc.lib._dagmc_enabled(),
+    not openmc.lib.feature_enabled('dagmc'),
     reason="DAGMC CAD geometry is not enabled.")
 
 

tests/unit_tests/dagmc/test_convert_to_multigroup.py

@@ -8,7 +8,7 @@
 import openmc.lib
 
 pytestmark = pytest.mark.skipif(
-    not openmc.lib._dagmc_enabled(),
+    not openmc.lib.feature_enabled('dagmc'),
     reason="DAGMC CAD geometry is not enabled.")
 
 

tests/unit_tests/dagmc/test_h5m_subdir.py

@@ -6,7 +6,7 @@
 import pytest
 
 pytestmark = pytest.mark.skipif(
-    not openmc.lib._dagmc_enabled(), reason="DAGMC CAD geometry is not enabled."
+    not openmc.lib.feature_enabled('dagmc'), reason="DAGMC CAD geometry is not enabled."
 )
 
 

tests/unit_tests/dagmc/test_lost_particles.py

@@ -7,7 +7,7 @@
 import pytest
 
 pytestmark = pytest.mark.skipif(
-    not openmc.lib._dagmc_enabled(),
+    not openmc.lib.feature_enabled('dagmc'),
     reason="DAGMC CAD geometry is not enabled.")
 
 

tests/unit_tests/dagmc/test_model.py

@@ -9,7 +9,7 @@
 from openmc.utility_funcs import change_directory
 
 pytestmark = pytest.mark.skipif(
-    not openmc.lib._dagmc_enabled(),
+    not openmc.lib.feature_enabled('dagmc'),
     reason="DAGMC CAD geometry is not enabled.")
 
 

tests/unit_tests/dagmc/test_plot.py

@@ -4,7 +4,7 @@
 
 
 pytestmark = pytest.mark.skipif(
-    not openmc.lib._dagmc_enabled(), reason="DAGMC CAD geometry is not enabled."
+    not openmc.lib.feature_enabled('dagmc'), reason="DAGMC CAD geometry is not enabled."
 )
 
 def test_plotting_dagmc_model(request):

tests/unit_tests/test_lib.py

@@ -315,6 +315,15 @@ def test_settings(lib_init):
     settings.seed = 11
 
 
+def test_feature_enabled():
+    assert isinstance(openmc.lib.feature_enabled('dagmc'), bool)
+    assert isinstance(openmc.lib.feature_enabled('libmesh'), bool)
+    assert isinstance(openmc.lib.feature_enabled('strict_fp'), bool)
+    assert isinstance(openmc.lib.feature_enabled('uwuw'), bool)
+    with pytest.raises(exc.InvalidArgumentError, match="Unknown build feature"):
+        openmc.lib.feature_enabled('not-a-feature')
+
+
 def test_tally_mapping(lib_init):
     tallies = openmc.lib.tallies
     assert isinstance(tallies, Mapping)

tests/unit_tests/test_mesh.py

@@ -453,7 +453,9 @@ def simple_umesh(request):
             return sp.meshes[1]
 
 
-@pytest.mark.skipif(not openmc.lib._dagmc_enabled(), reason="DAGMC not enabled.")
+@pytest.mark.skipif(
+    not openmc.lib.feature_enabled('dagmc'), reason="DAGMC not enabled."
+)
 @pytest.mark.parametrize('export_type', ('.vtk', '.vtu'))
 def test_umesh(run_in_tmpdir, simple_umesh, export_type):
     """Performs a minimal UnstructuredMesh simulation, reads in the resulting
@@ -507,9 +509,9 @@ def test_write_vtkhdf(mesh_file, mesh_library, request, run_in_tmpdir):
     necessary to read in the unstructured mesh from a statepoint file to ensure
     it has all the required attributes
     """
-    if mesh_library == 'moab' and not openmc.lib._dagmc_enabled():
+    if mesh_library == 'moab' and not openmc.lib.feature_enabled('dagmc'):
         pytest.skip("DAGMC not enabled.")
-    if mesh_library == 'libmesh' and not openmc.lib._libmesh_enabled():
+    if mesh_library == 'libmesh' and not openmc.lib.feature_enabled('libmesh'):
         pytest.skip("LibMesh not enabled.")
 
     model = openmc.Model()