‘CPyModule__ctypes’ undeclared

[juhasch]

Bug Report
When trying to use mypyc with ctypes, I get a compile error:

$ mypyc ioctl.py 
running build_ext
building 'ioctl' extension
gcc -pthread -B /home/mypy/source/compiler_compat -DNDEBUG -fwrapv -O2 -Wall -fPIC -O2 -isystem /home/mypy/source/include -fPIC -O2 -isystem /home/mypy/source/include -fPIC -I/home/mypy/source/lib/python3.11/site-packages/mypyc/lib-rt -I/home/mypy/source/include/python3.11 -c build/__native.c -o build/temp.linux-x86_64-cpython-311/build/__native.o -O3 -g1 -Werror -Wno-unused-function -Wno-unused-label -Wno-unreachable-code -Wno-unused-variable -Wno-unused-command-line-argument -Wno-unknown-warning-option -Wno-unused-but-set-variable -Wno-ignored-optimization-argument -Wno-cpp
build/__native.c: In function ‘CPyDef___top_level__’:
build/__native.c:189:17: error: ‘CPyModule__ctypes’ undeclared (first use in this function); did you mean ‘CPyModule_ctypes’?
  189 |     cpy_r_r19 = CPyModule__ctypes;
      |                 ^~~~~~~~~~~~~~~~~
      |                 CPyModule_ctypes
build/__native.c:189:17: note: each undeclared identifier is reported only once for each function it appears in
build/__native.c: At top level:
cc1: note: unrecognized command-line option ‘-Wno-ignored-optimization-argument’ may have been intended to silence earlier diagnostics
cc1: note: unrecognized command-line option ‘-Wno-unknown-warning-option’ may have been intended to silence earlier diagnostics
cc1: note: unrecognized command-line option ‘-Wno-unused-command-line-argument’ may have been intended to silence earlier diagnostics
error: command '/usr/bin/gcc' failed with exit code 1

To Reproduce
Test script ioctl.py:

import ctypes

class _GPIOchipInfo(ctypes.Structure):
    _fields_ = [
        ('name', ctypes.c_char * 32),
        ('label', ctypes.c_char * 32),
        ('lines', ctypes.c_uint32),
    ]

Workaround

Adding
#define CPyModule__ctypes CPyModule_ctypes
in the CPy.h include file "fixes" this error and the compiler succeeds.

Your Environment

• Mypy version used: 1.7.1
• Python version used: 3.11.6

[JotaRata]

Is mypyc meant to be used with ctypes?

If so what advatages does it have?

[DaanDeMeyer]

Same problem here. We're trying to compiler our script using mypyc to improve startup time. Our script uses ctypes to access features from libc and libseccomp that are not available in the standard library.