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Description
Bug report
Bug description:
I see a problem calling variadic functions imported from dynamic libraries under macOS on Apple Silicon.
I’m using a bit of code sample from https://docs.python.org/3/library/ctypes.html#specifying-the-required-argument-types-function-prototypes
First with Intel macOS Python (running via Rosetta):
% python3
Python 3.11.6 (main, Nov 3 2023, 03:33:27) [Clang 14.0.0 (clang-1400.0.29.202)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import platform
>>> platform.version()
'Darwin Kernel Version 23.3.0: Wed Dec 20 21:31:00 PST 2023; root:xnu-10002.81.5~7/RELEASE_ARM64_T6020'
>>> platform.processor()
'i386'
>>> from ctypes import *
>>> libc = cdll.LoadLibrary("libc.dylib")
>>> printf = libc.printf
>>> printf.argtypes = [c_char_p, c_char_p, c_int, c_double]
>>> printf(b"String '%s', Int %d, Double %f\n", b"Hi", 10, 2.2)
String 'Hi', Int 10, Double 2.200000
37
>>> And now with native Apple Silicon Python:
% python3
Python 3.11.7 (main, Dec 4 2023, 18:10:11) [Clang 15.0.0 (clang-1500.1.0.2.5)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import platform
>>> platform.version()
'Darwin Kernel Version 23.3.0: Wed Dec 20 21:31:00 PST 2023; root:xnu-10002.81.5~7/RELEASE_ARM64_T6020'
>>> platform.processor()
'arm'
>>> from ctypes import *
>>> libc = cdll.LoadLibrary("libc.dylib")
>>> printf = libc.printf
>>> printf.argtypes = [c_char_p, c_char_p, c_int, c_double]
>>> printf(b"String '%s', Int %d, Double %f\n", b"Hi", 10, 2.2)
String '(null)', Int 0, Double 0.000000
40
>>> As you can see the results are incorrect.
CPython versions tested on:
3.11
Operating systems tested on:
macOS