On 12 July 2016 at 19:23, Eric Blake <ebl...@redhat.com> wrote: > This violates POSIX, which requires that: > http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/stdint.h.html#tag_13_48 > "Each instance of these macros shall be replaced by a constant > expression suitable for use in #if preprocessing directives, and this > expression shall have the same type as would an expression that is an > object of the corresponding type converted according to the integer > promotions." > > That is, it is valid C to write '#if SIZE_MAX == 0xffffffff', while my > replacement fails that test: > > foo.c:6:26: error: missing binary operator before token "(" > #define SIZE_MAX ((sizeof(char)) * -1) > ^ > foo.c:7:5: note: in expansion of macro ‘SIZE_MAX’
I tested this patch with a compile on OSX, and it does compile without warnings or errors. (NB: haven't tested that it fixes the warning that was being complained about in the other patchset.) I don't have a very strong opinion about whether it's the best fix, but a couple of thoughts: * my inclination is to prefer not to override system headers except where we've checked and know they're broken (ie in a future world where Apple get their headers right I'd rather we automatically ended up using their version rather than ours) * we don't have any #if ...SIZE_MAX, but we do have some for other kinds of _MAX constant. thanks -- PMM