Replace Cython with the CPython limited API (abi3)

MANIFEST.in

@@ -1,4 +1,3 @@
 include README.md pyproject.toml setup.py SConstruct SConscript
-recursive-include site_scons *.py
-recursive-include msgq *.py *.pyx *.pxd *.h *.cc
+recursive-include msgq *.py *.h *.cc
 global-exclude *.so *.o *.os *.a *.pyc

SConscript

@@ -1,4 +1,4 @@
-Import('env', 'envCython', 'common')
+Import('env', 'envPython', 'common')
 
 
 visionipc_dir = Dir('msgq/visionipc')
@@ -10,7 +10,7 @@ msgq_objects = env.SharedObject([
   'msgq/msgq.cc',
 ])
 msgq = env.Library('msgq', msgq_objects)
-msgq_python = envCython.Program('msgq/ipc_pyx.so', 'msgq/ipc_pyx.pyx', LIBS=envCython["LIBS"]+[msgq]+common)
+msgq_python = envPython.Program('msgq/ipc_pyx.so', 'msgq/ipc_module.cc', LIBS=[msgq]+common)
 
 # Build Vision IPC
 vipc_files = ['visionipc.cc', 'visionipc_server.cc', 'visionipc_client.cc']
@@ -24,9 +24,8 @@ vipc_objects = env.SharedObject(vipc_sources)
 visionipc = env.Library('visionipc', vipc_objects)
 
 
-vipc_libs = envCython["LIBS"] + [visionipc, msgq] + common
-envCython.Program(f'{visionipc_dir.abspath}/visionipc_pyx.so', f'{visionipc_dir.abspath}/visionipc_pyx.pyx',
-                  LIBS=vipc_libs)
+envPython.Program(f'{visionipc_dir.abspath}/visionipc_pyx.so', f'{visionipc_dir.abspath}/visionipc_module.cc',
+                  LIBS=[visionipc, msgq]+common)
 
 if GetOption('extras'):
   env.Program('msgq/test_runner', ['msgq/msgq_tests.cc'], LIBS=[msgq]+common)

SConstruct

@@ -62,21 +62,18 @@ env = Environment(
   CFLAGS="-std=gnu11",
   CXXFLAGS="-std=c++1z",
   CPPPATH=cpppath,
-  CYTHONCFILESUFFIX=".cpp",
-  tools=["default", "cython"]
 )
 
 Export('env', 'arch', 'common')
 
-envCython = env.Clone(LIBS=[])
-envCython["CCFLAGS"] += ["-Wno-#warnings", "-Wno-cpp", "-Wno-shadow", "-Wno-deprecated-declarations"]
-envCython["CCFLAGS"].remove('-Werror')
+# Python extension modules use the limited API, so one build works on every Python >= 3.11
+envPython = env.Clone(LIBS=[])
 if arch == "Darwin":
-  envCython["LINKFLAGS"] = ["-bundle", "-undefined", "dynamic_lookup"]
+  envPython["LINKFLAGS"] = ["-bundle", "-undefined", "dynamic_lookup"]
 else:
-  envCython["LINKFLAGS"] = ["-pthread", "-shared"]
+  envPython["LINKFLAGS"] = ["-pthread", "-shared"]
 
-Export('envCython')
+Export('envPython')
 
 
 SConscript(['SConscript'])

lefthook.yml

@@ -18,12 +18,12 @@ test:
     ty:
       run: ty check .
     codespell:
-      run: codespell {files} -L ned,stdio,master --builtin clear,rare,informal,usage,code,names,en-GB_to_en-US -S uv.lock,*_pyx.cpp
+      run: codespell {files} -L ned,stdio,master --builtin clear,rare,informal,usage,code,names,en-GB_to_en-US -S uv.lock
       files: git ls-tree -r HEAD --name-only
     cppcheck:
-      run: cppcheck --error-exitcode=1 --inline-suppr --language=c++ --force --quiet -j4 --check-level=exhaustive $(git ls-files '*.cc' | grep -v -E '(msgq_tests|test_runner)\.cc')
+      run: cppcheck --error-exitcode=1 --inline-suppr --library=python --language=c++ --force --quiet -j4 --check-level=exhaustive $(git ls-files '*.cc' | grep -v -E '(msgq_tests|test_runner)\.cc')
     cpplint:
-      run: cpplint --exclude=msgq/ipc_pyx.cpp --exclude=msgq/visionipc/visionipc_pyx.cpp --recursive --quiet --counting=detailed --linelength=240 --filter=-build,-legal,-readability,-runtime,-whitespace,+build/include_subdir,+build/forward_decl,+build/include_what_you_use,+build/deprecated,+whitespace/comma,+whitespace/line_length,+whitespace/empty_if_body,+whitespace/empty_loop_body,+whitespace/empty_conditional_body,+whitespace/forcolon,+whitespace/parens,+whitespace/semicolon,+whitespace/tab,+readability/braces msgq/
+      run: cpplint --recursive --quiet --counting=detailed --linelength=240 --filter=-build,-legal,-readability,-runtime,-whitespace,+build/include_subdir,+build/forward_decl,+build/include_what_you_use,+build/deprecated,+whitespace/comma,+whitespace/line_length,+whitespace/empty_if_body,+whitespace/empty_loop_body,+whitespace/empty_conditional_body,+whitespace/forcolon,+whitespace/parens,+whitespace/semicolon,+whitespace/tab,+readability/braces msgq/
 
     # *** tests ***
     test_runner: