On Nov 6, 2011, at 1:58 PM, Alexander Best wrote: > On Sun Nov 6 11, Dimitry Andric wrote: >> On 2011-11-06 21:33, Alexander Best wrote: >> ... >>> the problem is, something like >>> >>> uint x; >>> >>> if (x < 0) ... >>> >>> clang will warn about this, yet it is 100% valid code so my vote would be to >>> make such an error into a warning. >> >> Sorry, but checking something unsigned to be smaller than zero is bogus, >> or at the least superfluous, and it's perfectly sane to warn about this, >> especially since the compiler is not going to emit code for it at all. > > there was a discussion with the topic > "disable -Wtautological-compare for clang" on freebsd-toolchain@ and most of > the devs considered this code *not* to be bogus. ;)
The code actually is bogus. It may be masking a real problem, because often times it is a "sanity check" to make sure that you aren't doing something naughty, like passing -1 for the length. However, if you then pass the unsigned through a signed value, it suddenly becomes negative, and you have a hard to spot bug. IIR the the tread, there weren't too many people offering an opinion... Warner_______________________________________________ freebsd-toolchain@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-toolchain To unsubscribe, send any mail to "freebsd-toolchain-unsubscr...@freebsd.org"
