gh-133157: remove usage of _Py_NO_SANITIZE_UNDEFINED in pyexpat#134050
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picnixz wants to merge 7 commits intopython:mainfrom
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gh-133157: remove usage of _Py_NO_SANITIZE_UNDEFINED in pyexpat#134050picnixz wants to merge 7 commits intopython:mainfrom
_Py_NO_SANITIZE_UNDEFINED in pyexpat#134050picnixz wants to merge 7 commits intopython:mainfrom
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Hum, looks like it worked. But I don't know why the pointer alternative didn't work (in clang it does?). I guess it's because of some optimization and it got eliminated (or maybe what I did was also a UB c:) |
bateller
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May 15, 2025
picnixz
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May 20, 2025
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@encukou Could you have a look at this one please? I don't have a better alternative than using hacky unions (though it's a recommended construction as per ISO C11) |
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I think this could be simpler, see #135346. But I might be missing something. |
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Closing in favor of #135346 |
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IIUC ISO C11, we can use "union casts" (which are actually compound literals, and thus constructors) to pass use unions. The idea is to consider each different function pointer as a union of possible function pointers and store them as such. In some sense, we're doing singledispatch with known registered types.