On Mon, Nov 11, 2013 at 9:41 AM, Eric Botcazou <ebotca...@adacore.com> wrote: >> But throw what? It is up to the runtimes of -fnon-call-exceptions languages >> to decide if they actually want to throw or do something else in the signal >> handlers, and what exactly to throw. > > Throw nothing per se, __builtin_throw would simply trap and ensure that the > exception thrown by the signal handlers can be handled properly, i.e. it would > be recognized by the exception machinery of the compiler as throwing.
Sorry, I don't understand what you are proposing. Simply trapping doesn't tell you anything about caused the trap. There are at least two distinct possibilities: NULL pointer dereference and integer division by zero. There should be some way to distinguish those two cases. It's reasonably easy to do so in a signal handler. When should we do if the compiler generate a call to __builtin_throw? Since I probably misunderstand, let me ask it a different way. Let's say there is code that the compiler can prove will dereference a NULL pointer. What should the compiler generate for that case? Ian
