Mark Dickinson <dicki...@gmail.com> added the comment: Thanks for the report; I agree that there's a potential issue here, and I also think that all these definitions *should* be preprocessor defines. (Idle question: does C99 require that LONG_MAX and friends are usable in the preprocessor? I see it in e.g. 7.18.2p2 for INT32_MAX and friends, but I'm not sure if there's something similar for LONG_MAX and co.)
Can you suggest a suitable fix for the PY_ULLONG_MAX and PY_LLONG_MAX defines? Note that a configure-based fix may need to take into account the special needs of Windows---for which configure isn't used, of course---and OS X---where the same code, based on a single run of configure, should be able to compile to the correct thing both in 32-bit and 64-bit mode, so that universal builds work; see PC/pyconfig.h and Include/pymacconfig.h respectively for dealing with these issues. BTW, do you know of any modern non-Windows platforms that don't define LLONG_MIN and LLONG_MAX? It may well be that the "two's complement" fallback hasn't been exercised in recent years. > Incidentally, the "two's complement" comment is wrong. > It also relies on unsigned long long being widest type with no > padding bits, and -LLONG_MAX-1 not being a trap representation. Agreed---that comment needs to be better. I think it's fine, though, for practical purposes to assume an absence of padding bits and no trap representation; IIRC there are places internally (e.g., in the bitwise operators section of the 'int' type implementation) that already assume two's complement + no padding bits + no trap representation. (I *thought* I had an old issue open somewhere about documenting---and possibly testing---these assumptions, but now I can't find it.) ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue10325> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
