On Fri, Aug 14, 2015 at 09:33:46AM -0600, Jeff Law wrote: > >Ok, I'll investigate and come back to y'all when/if I find something. > Thanks. I still regret using the TREE_TYPE as a way to chain elements in > the free list:( I didn't want to add another pointer field...
It's actually plain to see what's happening. Before isolate-paths we've got <bb 2>: ... SR.5_10 = MEM[(const struct A &)0B]; ... c_13 = C::size (&p1); ... if (_14 != 0) goto <bb 3>; else goto <bb 4>; <bb 3>: fn1 (&D.2434.OutBufCur, &b, c_13); Then in isolate-paths in find_explicit_erroneous_behaviour we're walking the stmts in bb 2 and we find a null dereference, so insert_trap_and_remove_trailing_statements comes in play and turns bb 2 into: <bb 2>: ... SR.5_10 = MEM[(const struct A &)0B]; __builtin_trap (); i.e. it removs the defining statement for c_13. Then find_explicit_erroneous_behaviour walks over bb 3, hits the fn1 (&D.2434.OutBufCur, &b, c_13); statement, and ICEs on the c_13 argument: it's a released SSA name with NULL TREE_TYPE. The question now is what to do with that. Skip SSA_NAME_IN_FREE_LIST? That sounds weird. Note that we're going to remove bb 3 and bb 4 anyway... Marek