On May 13 18:57, Corinna Vinschen wrote: > On May 13 18:41, Denis Excoffier wrote: > > On 2013-05-13 17:49, Corinna Vinschen wrote: > > > Erm... hang on. Is that really a problem? 2147483647 is 0x7fffffff, > > > which is the maximum you get with a 4 byte time_t (== signed long) > > > anyway. If you switch the date to 2038-01-20, the value will be > > > negative, and therefore outside the scope of the 4 byte time_t. So this > > > is a hard restriction of using 4 byte time_t. > > > > > > The solution is: > > > > > > - Either somebody changes 32 bit Cygwin to 8 byte time_t while keeping > > > all the 4 byte time_t APIs intact to maintain compatibility with > > > existing binaries(*), > > > > > > - or, you switch to a 64 bit Windows and use 64 bit Cygwin ;) > > > > > I understand. > > > > I suppose you will however be willing to provide us a means to workaround > > the "autoconf mktime usability test failing" (see for example in > > gawk-4.1.0 where all the tm fields are set to 128). Now, instead of only > > failing (i presume), it hangs. Sorry, this specific point should have been > > noticed in my original post. > > > > Or do we have to patch every impacted ./configure? > > Good point. I guess the right thing to do here is for mktime to > return -1 instead of hanging. I look into that.
Looks like this is a result of gcc optimization settings. The upstream code computing time_t <-> struct tm conversions requires integer overflow to be fully defined, but gcc's -O2 option sets -fstrict-overflow which results in all kinds of agressive integer optimizations which disabled utilizing integer overflows for serious purposes. I fixed that by setting the -fwrapv option when building the affected localtime.cc file (thanks to Kai Tietz for pointing this out). Corinna -- Corinna Vinschen Please, send mails regarding Cygwin to Cygwin Maintainer cygwin AT cygwin DOT com Red Hat -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple