https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70590
--- Comment #6 from Markus Trippelsdorf <trippels at gcc dot gnu.org> --- (In reply to Patrick Palka from comment #5) > (In reply to Markus Trippelsdorf from comment #4) > > (In reply to Patrick Palka from comment #3) > > > (In reply to Jakub Jelinek from comment #2) > > > > location references block not in block tree generally means insufficient > > > > unsharing, where some function that got through gimple-low.c where > > > > TREE_SET_BLOCK has been used on some of the trees is sharing trees with > > > > a > > > > different function. > > > > > > That makes sense. So in cxx_eval_call_expression we should > > > unconditionally > > > unshare the result of the call because the two caches (fundef_copies_table > > > and constexpr_call_table) may cause us to share the same trees in > > > different > > > functions. Alternatively we can just call unshare_expr once in the > > > top-level cxx_eval_outermost_constant_expression, I think. Markus, does > > > this patch fix the build for you? > > > > No. It now ICEs: in maybe_constant_value_1, at cp/constexpr.c:4328 > > What about just this instead? This one fixes the issue. Firefox now builds fine. Thanks.