New submission from tzickel: In Windows, there is a mechanizm called SEH that allows C/C++ programs to catch OS Exceptions (such as divide by zero, page faults, etc..).
Python's ctypes module for some reason forces the user to wrap all ctypes FFI calls with a special SEH wrapper that converts those exceptions to Python exceptions. For the UNIX people think about it that python installs a signal handler without you asking (or being able to remove it) when calling FFI functions. The main issue with this, is that when you want to debug why a DLL behaves badly and you want a process dump (or catch the stack trace in the DLL) you can't without attaching a debugger and catching first-chance exceptions (because the ctypes SEH handling masks the issue). My proposal is to have both in python 2 and in python 3 an option to call an FFI function with selectively using or not SEH. Here is the SEH wrap (as you can see it's not optional in runtime): https://github.com/python/cpython/blob/master/Modules/_ctypes/callproc.c#L806 ---------- components: ctypes messages: 254143 nosy: amaury.forgeotdarc, belopolsky, meador.inge, tzickel priority: normal severity: normal status: open title: Python 2 & 3 don't allow the user to disable ctypes SEH in windows type: behavior versions: Python 2.7, Python 3.6 _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue25562> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
