https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64780
--- Comment #1 from David Malcolm <dmalcolm at gcc dot gnu.org> --- We seem to have two choices here: (A) default to --enable-host-shared when jit is an enabled language (B) have the toplevel configure reject jit as language if --enable-host-shared is not supplied. FWIW apparently Darwin defaults to position-independent code, so it's not explicitly needed there. That said, I think I prefer (B), since there is a performance cost: my thinking here is that there are people who perform benchmarking of GCC (and publish their results on prominent websites). If they turn on the jit and use the same configuration to do their benchmarking of the rest of GCC, they'll see GCC 5 be apparently slower than earlier releases. You're a gcc expert, and you ran into this issue, so it's clearly unreasonable to expect a 3rd-party reviewer to notice this detail on their own. So I'm thinking of implementing (B), and putting in a note in the error message recommending that people configure and build GCC twice to avoid the performance hit, so that it can be self-documenting.
