On 07/02/2018 06:14 PM, Michael Matz wrote:
There is no such language in the psABI, no (at least I haven't found anything; you had me worried for a moment :) ). But there's stronger one: all functions through which unwinding is expected must provide CFI. So, yes, such code isn't strictly conforming. But there we are, there's much code that isn't and we still have to sensibly deal with it (if we can). IMHO making guesses is better than to stop unwinding. And IMHO guessing that it's FP-using is better than guessing that it's leaf, especially if the PC in question was the result of a prior unwinding step (making it clear that it certainly was_not_ leaf).
Well, the previous frame could have been a signal handler frame, but I see your point.
Anyway, I've proposed a BoF for these topics for the next Cauldron. Thanks, Florian
