[Bug middle-end/51212] ICE: verify_flow_info failed: BB 3 can not throw but has an EH edge with -fgnu-tm -fnon-call-exceptions and transaction_callable

[rth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51212

--- Comment #3 from Richard Henderson <rth at gcc dot gnu.org> 2011-12-21 
17:18:11 UTC ---
As far as the compiler goes that all sounds plausible.

The main problem is that we would have to make libitm exception safe.
I'm 100% sure that won't work at the moment.  I'm also sure that it
would be exceedingly awkward to take an exception in the middle of
the actual transaction.

Unless Torvald has a brilliant idea there, I'm inclined to simply
emit a sorry for combining -fgnu-tm and -fnon-call-exceptions.

Unless we redefine that combination such that we only support the
exception case for NULL, but non-null faulting memory references
just crash.  In that case we can simply test for NULL at the start
of the accessors and explicitly throw the exception.