Adding test to prevent gh-1344 from reoccuring

Adds a simple C extension, compiled with C compiler that includes
dpctl_capi header file. This mimics use dpctl_capi from numba_dpex.

Author: oleksandr-pavlyk

dpctl/tests/_c_ext.c

@@ -0,0 +1,110 @@
+//==- py_sycl-ls.c - Example of C extension working with                -===//
+//  DPCTLSyclInterface C-interface library.
+//
+//                      Data Parallel Control (dpctl)
+//
+// Copyright 2022 Intel Corporation
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// This file implements C Python extension using DPCTLSyclInterface library.
+///
+//===----------------------------------------------------------------------===//
+
+// clang-format off
+#include "Python.h"
+#include "dpctl_capi.h"
+// clang-format on
+
+PyObject *py_is_usm_ndarray(PyObject *self_unused, PyObject *args)
+{
+    PyObject *arg = NULL;
+    PyObject *res = NULL;
+    int status = -1;
+    int check = -1;
+
+    (void)(self_unused); // avoid unused arguments warning
+    status = PyArg_ParseTuple(args, "O", &arg);
+    if (!status) {
+        PyErr_SetString(PyExc_TypeError, "Expecting single argument");
+        return NULL;
+    }
+
+    check = PyObject_TypeCheck(arg, &PyUSMArrayType);
+    if (check == -1) {
+        PyErr_SetString(PyExc_RuntimeError, "Type check failed");
+        return NULL;
+    }
+
+    res = (check) ? Py_True : Py_False;
+    Py_INCREF(res);
+
+    return res;
+}
+
+PyObject *py_usm_ndarray_ndim(PyObject *self_unused, PyObject *args)
+{
+    PyObject *arg = NULL;
+    struct PyUSMArrayObject *array = NULL;
+    PyObject *res = NULL;
+    int status = -1;
+    int ndim = -1;
+
+    (void)(self_unused); // avoid unused arguments warning
+    status = PyArg_ParseTuple(args, "O!", &PyUSMArrayType, &arg);
+    if (!status) {
+        PyErr_SetString(
+            PyExc_TypeError,
+            "Expecting single argument of type dpctl.tensor.usm_ndarray");
+        return NULL;
+    }
+
+    array = (struct PyUSMArrayObject *)arg;
+    ndim = UsmNDArray_GetNDim(array);
+
+    res = PyLong_FromLong(ndim);
+    return res;
+}
+
+static PyMethodDef CExtMethods[] = {
+    {"is_usm_ndarray", py_is_usm_ndarray, METH_VARARGS,
+     "Checks if input object is an usm_ndarray instance"},
+    {"usm_ndarray_ndim", py_usm_ndarray_ndim, METH_VARARGS,
+     "Get ndim property of an usm_ndarray instance"},
+    {NULL, NULL, 0, NULL} /* Sentinel */
+};
+
+static struct PyModuleDef c_ext_module = {
+    PyModuleDef_HEAD_INIT,
+    "_c_ext", /* name of module */
+    "",       /* module documentation, may be NULL */
+    -1,       /* size of per-interpreter state of the module,
+                 or -1 if the module keeps state in global variables. */
+    CExtMethods,
+    NULL,
+    NULL,
+    NULL,
+    NULL};
+
+PyMODINIT_FUNC PyInit__c_ext(void)
+{
+    PyObject *m = NULL;
+
+    import_dpctl();
+
+    m = PyModule_Create(&c_ext_module);
+    return m;
+}

dpctl/tests/setup_c_ext.py

@@ -0,0 +1,32 @@
+#                      Data Parallel Control (dpctl)
+#
+# Copyright 2020-2023 Intel Corporation
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import setuptools
+
+import dpctl
+
+ext = setuptools.Extension(
+    "_c_ext",
+    ["_c_ext.c"],
+    include_dirs=[dpctl.get_include()],
+    language="c",
+)
+
+setuptools.setup(
+    name="test_c_ext",
+    version="0.0.0",
+    ext_modules=[ext],
+)

dpctl/tests/test_headers.py

@@ -0,0 +1,52 @@
+import pytest
+
+import dpctl
+import dpctl.tensor as dpt
+
+
+@pytest.fixture(scope="session")
+def dpctl_c_extension(tmp_path_factory):
+    import os
+    import os.path
+    import shutil
+    import subprocess
+    import sys
+    import sysconfig
+
+    curr_dir = os.path.dirname(__file__)
+    dr = tmp_path_factory.mktemp("_c_ext")
+    for fn in ["_c_ext.c", "setup_c_ext.py"]:
+        shutil.copy(
+            src=os.path.join(curr_dir, fn),
+            dst=dr,
+            follow_symlinks=False,
+        )
+    res = subprocess.run(
+        [sys.executable, "setup_c_ext.py", "build_ext", "--inplace"],
+        cwd=dr,
+        env=os.environ,
+    )
+    if res.returncode == 0:
+        import glob
+        from importlib.util import module_from_spec, spec_from_file_location
+
+        sfx = sysconfig.get_config_vars()["EXT_SUFFIX"]
+        pth = glob.glob(os.path.join(dr, "_c_ext*" + sfx))
+        if not pth:
+            pytest.fail("C extension was not built")
+        spec = spec_from_file_location("_c_ext", pth[0])
+        builder_module = module_from_spec(spec)
+        spec.loader.exec_module(builder_module)
+        return builder_module
+    else:
+        pytest.fail("C extension could not be built")
+
+
+def test_c_headers(dpctl_c_extension):
+    try:
+        x = dpt.empty(10)
+    except (dpctl.SyclDeviceCreationError, dpctl.SyclQueueCreationError):
+        pytest.skip()
+
+    assert dpctl_c_extension.is_usm_ndarray(x)
+    assert dpctl_c_extension.usm_ndarray_ndim(x) == x.ndim