http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49820
--- Comment #14 from Eric Botcazou <ebotcazou at gcc dot gnu.org> 2011-07-27 11:23:25 UTC --- > My example does indeed give a warning when compiled with -Wstrict-overflow=2. > Unfortunately, -Wall implies only -Wstrict-overflow=1 so I got no warning in > the first place. I think the warning levels need to be adjusted so that we get > the warning with -Wall because the consequences are no less serious than > ignoring an overflow check with if(a+const<a), which gives a warning with > -Wstrict-overflow=1 If you are doing clever things, adjust the warning level you're using. They have been chosen after considering several trade-offs, so changing them would entail redoing the full analysis. Patches welcome.
