https://gcc.gnu.org/bugzilla/show_bug.cgi?id=18487
--- Comment #29 from Daniel Berlin <dberlin at gcc dot gnu.org> --- Let me try to explain a different way: The only functions GCC can warn about are those that don’t need the attributes in the first place. The way any warning would work is to detect whether it is pure/const, and then see how the user marked it. So anything it can properly detect as right or wrong didn’t need an attribute to begin with - the compiler could already tell if it was pure/const Rather than tell the user they got it wrong, you might as well tell the user to remove the attribute because it isn’t necessary and won’t be necessary. This is precisely why attributes are meant for when you are sure you know more than the compiler can tell, and *no other time *. It is a tool for experts. Giving a bunch of really contrived examples where users may update things wrong doesn’t seem like a good motivation to make a warning that can only possibly have a really high false positive rate. The same logic applies to a lot of expert-use-only attributes. It is assumed you know what you are doing, because the compiler can’t tell you you are wrong accurately On Sat, Sep 4, 2021 at 4:40 PM federico.kircheis at gmail dot com < gcc-bugzi...@gcc.gnu.org> wrote: > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=18487 > > --- Comment #28 from Federico Kircheis <federico.kircheis at gmail dot > com> --- > >Edit: sorry, my last comment about what GCC thinks is wrong. > > Unless it is going to inline the function call, in that case the > attributes are > as-if ignored (at least the case I've tested with GCC 11.2). > > -- > You are receiving this mail because: > You are on the CC list for the bug.
