[Bug lto/45375] [meta-bug] Issues with building Mozilla with LTO

[hubicka at ucw dot cz]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45375

--- Comment #104 from Jan Hubicka <hubicka at ucw dot cz> 2011-06-18 08:53:37 UTC ---
> Even with 8c1fce46fc0 reverted libxul fails to link during
> a profiledbuild. Normal build is fine.

I didn't really tested profiledbuild for a while, so I will check.
Last time I tried we was able to build libxul but still had problems
building one of later libraries because of the COMDAT issues. I filled
Mozilla PR for that (the problem really is including some classes but not
linking with their implementation).

What worked well for me is to profile w/o LTO and LTO final build.  This is
recommended way anyway as LTO -fprofile-generae build is unnecesarily
expensive.

What is the official way of building mozilla with FDO?

Does the non-FDO problem persist for you?  The Jul 10 commit was part of
longer series of alias rewrite and I fixed some of fallout afterwards (and
was able to build mozilla).  Didn't see the particular problem you report
however.

Honza