On Thursday, 12 November 2015 at 06:50:31 UTC, Walter Bright
wrote:
The tricky part with the personality function will likely be
recognizing std::exception* exceptions. I wonder if forwarding
the call to __gxx_personality_v0 will work.
This should be rather simple; you know it is C++ because of the
metadata, and if you have access to RTTI (can just be hacked
together with pragma(mangle, …)), you just do the type comparison
then.
What has me quite a bit more worried is the lifetime handling
involved in the usual "throw std::exception subclass by value,
catch base class by reference" idiom. If I remember correctly,
both GCC and Clang handle this by injecting a runtime function
call into the end of the catch blocks. Their implementation must
also support keeping the value around for rethrowing. At this
point, I'm not aware of any fundamental incompatibilities, but it
will certainly add to the complexity of the solution.
— David
