Padraig O'Sullivan wrote: > On Wed, Nov 11, 2009 at 9:07 AM, Paul McCullagh > <[email protected]> wrote: >> Hi Padraig, >> >> On Nov 11, 2009, at 2:56 PM, Padraig O'Sullivan wrote: >> >>>> Just one change I am not sure of: >>>> >>>> datalog_xt.cc: line 1206 >>>> >>>> #ifdef DEBUG >>>> if (dlb_buffer_offset + (xtLogOffset) dlb_buffer_len > >>>> dlb_max_write_offset) >>>> dlb_max_write_offset = dlb_buffer_offset + >>>> (xtLogOffset) dlb_buffer_len; >>>> #endif >>>> >>>> --> >>>> >>>> #ifdef DEBUG >>>> if (dlb_buffer_offset + dlb_buffer_len > >>>> dlb_max_write_offset) >>>> dlb_max_write_offset = dlb_buffer_offset + >>>> (xtLogOffset) dlb_buffer_len; >>>> #endif >>>> >>>> This is a case of "off_t + size_t > off_t". >>>> >>>> The size_t was cast to an off_t in case size_t is 4 bytes and off_t is 8. >>>> >>>> So we want to make sure that the calculation is done using 8 byte values >>>> in >>>> this case. >>>> >>>> Did you get a warning on this line? Maybe due to signed to unsigned >>>> conversion? >>> Sorry, that's my bad. I meant to revert that change before commiting. >>> Yes, I had gotten a warning to do with comparison of signed and >>> unsigned integers in a few places in that file. I was going to try and >>> fix those warnings but then decided it would be better to not do that >>> and just updated the compiler flags to include -Wno-sign-compare >>> instead. >> Turning the warning off is a quick solution, but I would really like to know >> how to write this code so that all compilers are happy! >> >> I have no problem with changing the code, but I don't want to change it, >> just to run into a warning on some other system. > > Ah, ok. I didn't change anything as I wasn't sure if things were done > like that for a certain reason or not. The warning pops up in quite a > few places in that file for me when I compile with debug symbols. > >> In particular, I am wondering why the compiler is generating a warning in >> this case where we have an explicit conversion? > > I'm not sure either and would be interested in learning if someone > could provide an answer.
/me reminds myself to read _all_ of the morning email before beginning to respond. :) Lemme take a peek at it and see if I can get you an answer on that. Monty _______________________________________________ Mailing list: https://launchpad.net/~drizzle-discuss Post to : [email protected] Unsubscribe : https://launchpad.net/~drizzle-discuss More help : https://help.launchpad.net/ListHelp
