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Author vstinner
Recipients Mark.Shannon, kj, vstinner
Date 2022-03-30.14:33:08
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Message-id <>
GH-32192 "Add _PyCFunction_CAST() macro" is special. It's used to define functions in PyTypeObject.tp_methods or PyModuleDef.m_methods.

Casting a function pointer can cause issues with Control Flow Integrity (CFI) implemented in LLVM. The _thread module has an undefined behavior fixed by the commit 9eea6eaf23067880f4af3a130e3f67c9812e2f30 of bpo-33015. Previously, a cast ignored that the callback has no return value, whereas pthread_create() requires a function which as a void* return value.

To fix compiler warnings, the (PyCFunction)func cast was replaced with the (PyCFunction)(void(*)(void))func cast to fix bpo-bpo-33012 GCC 8 compiler warning:

    warning: cast between incompatible function types (...)
Date User Action Args
2022-03-30 14:33:08vstinnersetrecipients: + vstinner, Mark.Shannon, kj
2022-03-30 14:33:08vstinnersetmessageid: <>
2022-03-30 14:33:08vstinnerlinkissue47164 messages
2022-03-30 14:33:08vstinnercreate