Add rule python.cython

[Freed-Wu]

• Before adding new features and new modules, please go to issues to submit the relevant feature description first.
• Write good commit messages and use the same coding conventions as the rest of the project.
• Please commit code to dev branch and we will merge into master branch in feature
• Ensure your edited codes with four spaces instead of TAB.

---

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Future work:

• rule python.module to set the correct extension for python module.
• rule python.autopxd to convert *.h to *.pxd
• allow rule python.cython to output C++
• allow rule python.cython to use -I for *.pxd

cython use a header file with extension pxd. Should we use same add_includedirs() for it?
That is, if we

add_includedirs(".")

We will

cython -3omain.c -I. main.py

[Freed-Wu]

print(1)

$ cython -3omain.c main.py
$ cythonize -b main.c
$ python -c 'import main'
1

For xmake:

add_rules("mode.debug", "mode.release")
add_requires("python 3.x")

rule("python.cython")
    set_extensions(".py", ".pyx")
    before_buildcmd_file(function(target, batchcmds, sourcefile, opt)
        local language = target:extraconf("rules", "python.cython", "language")
        local ext
        local arg = "-3"
        if language == "c" then
            ext = "c"
            local rule = target:rule("python.cython"):clone()
            rule:add("deps", "c", {order = true})
            target:rule_add(rule)
        elseif language == "c++" then
            ext = "cc"
            arg = arg .. "+"
            local rule = target:rule("python.cython"):clone()
            rule:add("deps", "c++", {order = true})
            target:rule_add(rule)
        end
        local dirname = path.join(target:autogendir(), "rules", "python", "cython")
        local sourcefile_c = path.join(dirname, path.basename(sourcefile) .. "." .. ext)

        -- add objectfile
        local objectfile = target:objectfile(sourcefile_c)
        table.insert(target:objectfiles(), objectfile)

        -- add commands
        batchcmds:show_progress(opt.progress, "${color.build.object}compiling.python %s", sourcefile)
        batchcmds:mkdir(path.directory(sourcefile_c))
        import("lib.detect.find_tool")
        local cython = find_tool("cython")
        assert(cython, "cython not found! please `pip install cython`.")
        batchcmds:vrunv(cython.program,
            { arg, "-o", path(sourcefile_c), path(sourcefile) })
        batchcmds:compile(sourcefile_c, objectfile)

        -- add deps
        batchcmds:add_depfiles(sourcefile)
        batchcmds:set_depmtime(os.mtime(objectfile))
        batchcmds:set_depcache(target:dependfile(objectfile))
    end)

target("main")
add_rules("python.library", "python.cython", { soabi = true, language = "c++" })
add_files("src/*.py")
add_packages("python")

$ xmake --rebuild --verbose
[ 50%]: compiling.python src/main.py
/usr/bin/cython -3+ -o build/.gens/shm/linux/x86_64/release/rules/python/cython/main.cc src/main.py
/usr/bin/gcc -c -m64 -fPIC -fvisibility=hidden -fvisibility-inlines-hidden -O3 -isystem /usr/include/python3.13 -DNDEBUG -o build/.objs/shm/linux/x86_64/release/gens/rules/python/cython/main.cc.o build/.gens/shm/linux/x86_64/release/rules/python/cython/main.cc
checking for g++ ... /usr/bin/g++
checking for the shared library linker (sh) ... g++
checking for flags (-fPIC) ... ok
[ 75%]: linking.release shm.cpython-313-x86_64-linux-gnu.so
/usr/bin/g++ -o build/linux/x86_64/release/shm.cpython-313-x86_64-linux-gnu.so build/.objs/shm/linux/x86_64/release/gens/rules/python/cython/main.cc.o -shared -m64 -fPIC
[100%]: build ok, spent 0.804s
$ cd build/linux/x86_64/release/
$ python -c 'import main'
Traceback (most recent call last):
  File "<string>", line 1, in <module>
    import main
ImportError: dynamic module does not define module export function (PyInit_main)

[Freed-Wu]

python.library should be renamed to python.module, same as nodejs.module, lua.module, platform.linux.module, etc.

[waruqi]

please add some examples in tests

[waruqi]

please add an example in https://github.com/xmake-io/xmake/tree/dev/tests/projects/pybind