https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85091
Richard Biener <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |WAITING Last reconfirmed| |2018-03-27 Ever confirmed|0 |1 --- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> --- This looks like a GC / memory corruption issue to me. Can you check whether using -fchecking uncovers anything? I expect the issue will be impossible to reproduce for us, can you nevertheless please reproduce the output of i686-w64-mingw32-g++ -c -std=c++17 -Wnonnull -Woverloaded-virtual -O2 -v 16795.cpp ? That is, if you append '-v'?