----- Original Message ----- > From: "Aaron Ballman via cfe-commits" <cfe-commits@lists.llvm.org> > To: "Joshua Hurwitz" <hurwi...@google.com> > Cc: "cfe-commits" <cfe-commits@lists.llvm.org> > Sent: Tuesday, November 15, 2016 12:17:28 PM > Subject: Re: [PATCH] Warning for main returning a bool. > > On Fri, Oct 14, 2016 at 1:17 PM, Joshua Hurwitz via cfe-commits > <cfe-commits@lists.llvm.org> wrote: > > See attached. > > > > Returning a bool from main is a special case of return type > > mismatch. The > > common convention when returning a bool is that 'true' (== 1) > > indicates > > success and 'false' (== 0) failure. But since main expects a return > > value of > > 0 on success, returning a bool is usually unintended. > > I am not convinced that this is a high-value diagnostic. Returning a > Boolean from main() may or may not be a bug (the returned value is > generally a convention more than anything else). Also, why Boolean > and > not, say, long long or float?
I've seen this error often enough, but I think we need to be careful about false positives here. I recommend that we check only for explicit uses of boolean immediates (i.e. return true; or return false;) -- these are often bugs. Aaron, I disagree that the return value is just some kind of convention. It has a clear meaning. Furthermore, the behavior of the system can be quite different for a non-zero exit code than otherwise, and users who don't understand what's going on can find it very difficult to understand what's going wrong. Thanks again, Hal > > ~Aaron > > > > > _______________________________________________ > > cfe-commits mailing list > > cfe-commits@lists.llvm.org > > http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits > > > _______________________________________________ > cfe-commits mailing list > cfe-commits@lists.llvm.org > http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits > -- Hal Finkel Lead, Compiler Technology and Programming Languages Leadership Computing Facility Argonne National Laboratory _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
