Add check of element hash

.github/workflows/oneapi.yml

@@ -87,7 +87,7 @@ jobs:
       - name: Build DOLFINx Python interface
         run: |
           . /opt/intel/oneapi/setvars.sh
-          pip -v install --check-build-dependencies --no-build-isolation python/
+          pip -v install --check-build-dependencies --no-build-isolation --config-settings=cmake.build-type="Developer" python/
       - name: Set default DOLFINx JIT options
         run: |
           mkdir -p ~/.config/dolfinx

cpp/dolfinx/fem/utils.h

@@ -360,13 +360,17 @@ Form<T, U> create_form_factory(
   }
 
   // Check argument function spaces
-#ifndef NDEBUG
   for (std::size_t i = 0; i < spaces.size(); ++i)
   {
     assert(spaces[i]->element());
-    // TODO: Hash check of element
+    if (auto element_hash = ufcx_form.finite_element_hashes[i];
+        element_hash != 0
+        and element_hash != spaces[i]->element()->basix_element().hash())
+    {
+      throw std::runtime_error("Cannot create form. Elements are different to "
+                               "those used to compile the form.");
+    }
   }
-#endif
 
   // Extract mesh from FunctionSpace, and check they are the same
   if (!mesh and !spaces.empty())

python/test/unit/fem/test_forms.py

@@ -10,7 +10,11 @@
 
 import pytest
 
+import basix
+import basix.ufl
+import dolfinx
 from dolfinx.fem import extract_function_spaces, form, functionspace
+from dolfinx.fem.forms import form_cpp_class
 from dolfinx.mesh import create_unit_square
 from ufl import TestFunction, TrialFunction, dx, inner
 
@@ -48,3 +52,60 @@ def test_extract_forms():
     assert Vr[1] is V1._cpp_object
     with pytest.raises(AssertionError):
         extract_function_spaces(a, 1)
+
+
+def test_incorrect_element():
+    """Test that an error is raised if an incorrect element is used."""
+    mesh = create_unit_square(MPI.COMM_WORLD, 32, 31)
+    element = basix.ufl.element(
+        "Lagrange",
+        "triangle",
+        4,
+        lagrange_variant=basix.LagrangeVariant.gll_warped,
+        dtype=dolfinx.default_real_type,
+    )
+    incorrect_element = basix.ufl.element(
+        "Lagrange",
+        "triangle",
+        4,
+        lagrange_variant=basix.LagrangeVariant.equispaced,
+        dtype=dolfinx.default_real_type,
+    )
+
+    space = functionspace(mesh, element)
+    incorrect_space = functionspace(mesh, incorrect_element)
+
+    u = TrialFunction(space)
+    v = TestFunction(space)
+
+    a = inner(u, v) * dx
+
+    dtype = dolfinx.default_scalar_type
+    ftype = form_cpp_class(dtype)
+
+    ufcx_form, module, code = dolfinx.jit.ffcx_jit(
+        mesh.comm, a, form_compiler_options={"scalar_type": dtype}
+    )
+
+    f = ftype(
+        module.ffi.cast("uintptr_t", module.ffi.addressof(ufcx_form)),
+        [space._cpp_object, space._cpp_object],
+        [],
+        [],
+        {dolfinx.cpp.fem.IntegralType.cell: []},
+        {},
+        mesh._cpp_object,
+    )
+    dolfinx.fem.Form(f, ufcx_form, code)
+
+    with pytest.raises(RuntimeError):
+        f = ftype(
+            module.ffi.cast("uintptr_t", module.ffi.addressof(ufcx_form)),
+            [incorrect_space._cpp_object, incorrect_space._cpp_object],
+            [],
+            [],
+            {dolfinx.cpp.fem.IntegralType.cell: []},
+            {},
+            mesh._cpp_object,
+        )
+        dolfinx.fem.Form(f, ufcx_form, code)