It appears that sjlj exceptions are broken (PRs 19774/25266/28493). I'm not sure this is true for _every_ target, but it appears to be true for many.
So it seems that those of us affected by this bug have three workarounds: 1) compile everything with -fno-exceptions and remove all eh from project code 2) implement dwarf2 eh for the target 3) fix the #19774 regression Given the relative significance of tasks #1 and #2, I'm surprised that a fix for #19774 isn't higher priority. In any case, I am attempting to fix it myself. I have been dumping trees and have narrowed it down to either the eh or vregs RTL pass, and would be glad to hear if anyone else has information on this problem. Aaron