On Wed, Dec 24 2014, Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> wrote: > On Tue, 2014-12-23 at 11:01 -0800, Linus Torvalds wrote: >> On Tue, Dec 23, 2014 at 5:16 AM, Rasmus Villemoes <rv@xxxxxxxxxxxxxxxxxx> wrote: >> > There doesn't seem to be any reason for the special member of struct >> > token to be unsigned; AFAICT it is only ever being directly compared >> > to explicit characters and the SPECIAL_* enum constants using ==, != >> > and in a switch statement. Making it plain int avoids an annoying >> > warning from match_op in token.h when compiling with -Wsign-compare. >> >> Please don't use -Wsign-cpmpare to make decisions about code. >> >> "unsigned" is generally the much preferred type if there are no >> reasons for it to be signed. And -Wsign-compare on its own is not a >> reason, since it gives insane warnings for good code. >> >> -Wsign-compare is basically a "you can walk through the warnings and >> see if any of them are actually valid" thing. It's not worth it in any >> other form. Trying to be sign-compare clean will result in actively >> *worse* code in some circumstances (ie pointless casts etc etc). > > Additionally "compare with characters" trips another flag, chars are > unsigned by default on some archs :) And signed on others... if anything, that seems to be an argument _for_ the patch, since an int can always represent the entire range of char, while that is not true for unsigned. Anyway, I'm not going to pursue this further. Rasmus -- To unsubscribe from this list: send the line "unsubscribe linux-sparse" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
