------- Comment #4 from hubicka at ucw dot cz 2009-02-17 18:01 ------- Subject: Re: LTO and -fwhole-program do not play along well
> > Hi, > > functions are brought local in function_and_variable_visibility that > > needs to be scheduled after LTO is read in. > > The pas computes externaly_visible flags that should be up-to-date for > > early IPA passes before LTO is written out, so I guess we need early > > function_and_vairable_visibility pass and late one where the first one > > is not bringing functions local at -fwhole-program -lto > > OK, but I think there is a bigger issue here. Even if -flto is *not* > used, we get link errors. Just by compiling each file with > -fwhole-program is enough to reproduce the failure: > > $ gcc -fwhole-program -c f1.c > $ gcc -fwhole-program -c f2.c > $ gcc -fwhole-program -o f f1.o f2.o > > This is just a natural side-effect of using -fwhole-program. It was > not intended to be used like this. This is intended behaviour. -fwhole-program essentially hides everything except for main and functions/variables explicitly marked via attribute, so this is exepcted. You need to use --combine and or -lto to compile programs consisting of multiple compilation units with -fwhole-program. Honza -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39203
