Peter Maydell <peter.mayd...@linaro.org> writes: > 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)
That's a good point. > * we don't have any #if ...SIZE_MAX, but we do have some > for other kinds of _MAX constant.
