""" Task definitions for invoke command line utility for python bindings

overview article.

"""

import cffi

import invoke

import pathlib

import sys

import os

import shutil

import re

import glob

on_win = sys.platform.startswith("win")

@invoke.task

def clean(c):

"""Remove any built objects"""

for file_pattern in (

"*.o",

"*.so",

"*.obj",

"*.dll",

"*.exp",

"*.lib",

"*.pyd",

"cffi_example*", # Is this a dir?

"cython_wrapper.cpp",

):

for file in glob.glob(file_pattern):

os.remove(file)

for dir_pattern in "Release":

for dir in glob.glob(dir_pattern):

shutil.rmtree(dir)

def print_banner(msg):

print("==================================================")

print("= {} ".format(msg))

@invoke.task()

def build_cmult(c, path=None):

"""Build the shared library for the sample C code"""

# Moving this type hint into signature causes an error (???)

c: invoke.Context

if on_win:

if not path:

print("Path is missing")

else:

# Using c.cd didn't work with paths that have spaces :/

path = f'"{path}vcvars32.bat" x86' # Enter the VS venv

path += f'&& cd "{os.getcwd()}"' # Change to current dir

path += "&& cl /LD cmult.c" # Compile

# Uncomment line below, to suppress stdout

# path = path.replace("&&", " >nul &&") + " >nul"

c.run(path)

else:

print_banner("Building C Library")

cmd = "gcc -c -Wall -Werror -fpic cmult.c -I /usr/include/python3.7"

invoke.run(cmd)

invoke.run("gcc -shared -o libcmult.so cmult.o")

print("* Complete")

@invoke.task()

def test_ctypes(c):

"""Run the script to test ctypes"""

print_banner("Testing ctypes Module for C")

# pty and python3 didn't work for me (win).

if on_win:

invoke.run("python ctypes_c_test.py")

else:

invoke.run("python3 ctypes_c_test.py", pty=True)

@invoke.task()

def test_ctypes_cpp(c):

"""Run the script to test ctypes"""

print_banner("Testing ctypes Module for C++")

# pty and python3 didn't work for me (win).

if on_win:

invoke.run("python ctypes_cpp_test.py")

else:

invoke.run("python3 ctypes_cpp_test.py", pty=True)

@invoke.task()

def build_cffi(c):

"""Build the CFFI Python bindings"""

print_banner("Building CFFI Module")

ffi = cffi.FFI()

this_dir = pathlib.Path().resolve()

h_file_name = this_dir / "cmult.h"

with open(h_file_name) as h_file:

# cffi does not like our preprocessor directives, so we remove them

lns = h_file.read().splitlines()

flt = filter(lambda ln: not re.match(r" *#", ln), lns)

flt = map(lambda ln: ln.replace("EXPORT_SYMBOL ", ""), flt)

ffi.cdef(str("\n").join(flt))

ffi.set_source(

"cffi_example",

# Since we are calling a fully built library directly no custom source

# is necessary. We need to include the .h files, though, because behind

# the scenes cffi generates a .c file which contains a Python-friendly

# wrapper around each of the functions.

'#include "cmult.h"',

# The important thing is to include the pre-built lib in the list of

# libraries we are linking against:

libraries=["cmult"],

library_dirs=[this_dir.as_posix()],

extra_link_args=["-Wl,-rpath,."],

)

ffi.compile()

print("* Complete")

@invoke.task()

def test_cffi(c):

"""Run the script to test CFFI"""

print_banner("Testing CFFI Module")

invoke.run("python cffi_test.py", pty=not on_win)

@invoke.task()

def build_cppmult(c):

"""Build the shared library for the sample C++ code"""

print_banner("Building C++ Library")

invoke.run(

"g++ -O3 -Wall -Werror -shared -std=c++11 -fPIC cppmult.cpp "

"-o libcppmult.so "

)

print("* Complete")

def compile_python_module(cpp_name, extension_name):

invoke.run(

"g++ -O3 -Wall -Werror -shared -std=c++11 -fPIC "

"`python3 -m pybind11 --includes` "

"-I /usr/include/python3.7 -I . "

"{0} "

"-o {1}`python3.7-config --extension-suffix` "

"-L. -lcppmult -Wl,-rpath,.".format(cpp_name, extension_name)

)

@invoke.task(build_cppmult)

def build_pybind11(c):

"""Build the pybind11 wrapper library"""

print_banner("Building PyBind11 Module")

compile_python_module("pybind11_wrapper.cpp", "pybind11_example")

print("* Complete")

@invoke.task()

def test_pybind11(c):

"""Run the script to test PyBind11"""

print_banner("Testing PyBind11 Module")

invoke.run("python3 pybind11_test.py", pty=True)

@invoke.task(build_cppmult)

def build_cython(c):

"""Build the cython extension module"""

print_banner("Building Cython Module")

# Run cython on the pyx file to create a .cpp file

invoke.run("cython --cplus -3 cython_example.pyx -o cython_wrapper.cpp")

# Compile and link the cython wrapper library

compile_python_module("cython_wrapper.cpp", "cython_example")

print("* Complete")

@invoke.task()

def test_cython(c):

"""Run the script to test Cython"""

print_banner("Testing Cython Module")

invoke.run("python3 cython_test.py", pty=True)

@invoke.task(

clean,

build_cmult,

build_cppmult,

test_ctypes,

test_ctypes_cpp,

build_cffi,

test_cffi,

build_pybind11,

test_pybind11,

build_cython,

test_cython,

)

def all(c):

"""Build and run all tests"""

pass