Add support for dpNP (#12)

* Add support for dpNP

Support for dpNP requires biulding of Cython module.

* Small fixes

Add dpnp in conda build dependencies.
Add missing comma in setup.py.
Import module os and Extension class.

conda-recipe/meta.yaml

@@ -20,6 +20,7 @@ requirements:
         - llvm-spirv
         - numba
         - dpctl
+        - dpnp
     run:
         - python
         - numba >=0.51

setup.py

@@ -1,7 +1,39 @@
-from setuptools import find_packages, setup
+import os
+from setuptools import Extension, find_packages, setup
+from Cython.Build import cythonize
 
-packages = find_packages(include=["numba_dppy", "numba_dppy.*"])
 
+def get_ext_modules():
+    ext_modules = []
+
+    dpnp_present = False
+    try:
+        import dpnp
+    except:
+        pass
+    else:
+        dpnp_present = True
+
+    if dpnp_present:
+        dpnp_lib_path = []
+        dpnp_lib_path += [os.path.dirname(dpnp.__file__)]
+        ext_dpnp_glue = Extension(name='numba_dppy.dpnp_glue.dpnp_fptr_interface',
+                                  sources=['numba_dppy/dpnp_glue/dpnp_fptr_interface.pyx'],
+                                  include_dirs=[dpnp.get_include()],
+                                  libraries=['dpnp_backend_c'],
+                                  library_dirs=dpnp_lib_path,
+                                  runtime_library_dirs=dpnp_lib_path,
+                                  language="c++")
+        ext_modules += [ext_dpnp_glue]
+
+    if dpnp_present:
+        return cythonize(ext_modules)
+    else:
+        return ext_modules
+
+
+packages = find_packages(include=["numba_dppy", "numba_dppy.*"])
+build_requires = ["cython"]
 install_requires = [
     "numba",
     "dpctl",
@@ -13,7 +45,9 @@
     description="Numba extension for Intel CPU and GPU backend",
     url="https://github.com/IntelPython/numba-dppy",
     packages=packages,
+    setup_requires=build_requires,
     install_requires=install_requires,
+    ext_modules=get_ext_modules(),
     author="Intel Corporation",
     classifiers=[
         "Development Status :: 4 - Beta",