https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69383
Jonathan Wakely <redi at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |WAITING Last reconfirmed| |2016-01-20 Ever confirmed|0 |1 --- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> --- Please provide preprocessed source so I can see what silliness Firefox does this time, but basically this is undefined behaviour: In file included from ../../../dist/system_wrappers/stdlib.h:3:0, from ../../../dist/include/mozilla/mozalloc.h:15, from ../../../dist/stl_wrappers/cstdlib:39, I'm not going to hold off fixing bugs in the real standard library because of projects that have their own fake standard library with undefined behaviour.