On Thursday, 25 February 2016 at 02:58:08 UTC, Walter Bright
wrote:
A big chunk of that was getting D to catch C++ exceptions. And
before I did this work, neither GDC nor LDC did, either. It's
not a simple matter of just turning it on given Dwarf EH.
That's beside the point, the C++ interop needed to be worked out
either way and is not specific to the DMD backend. In that stupid
example I gave, I was referring to the DWARF EH implementation
itself, which will have taken you a non-negligible amount of time
due to all the barely documented details, unless you are even
more of a super-human compiler implementation expert than I
already know you are. ;)
Don't get me wrong, I couldn't care less about the details of how
long it took whom to implement C++ EH interop (or the fact that
it did exist before in LDC/Calypso, and in the form of prototypes
for vanilla GDC/LDC, etc.).
I'm only playing devil's advocate because many people here make
it seem as if there was no cost to supporting multiple compilers,
while there most definitely is. This ranges from the blatant
duplication of work over PR issues to the fact that big
language/compiler features are all but impossible to implement
for anybody but you, since you are the only one who knows how to
implement them on DMD (and in the current situation, not having
them available in DMD would be a deal-breaker).
Sure, the fact that you know all the nitty-gritty details of one
backend might make implementing certain changes easier for you,
as you pointed out. But the fact that this one backend is obscure
compared to the usual suspects, poorly documented and
license-encumbered pretty much ensures that you will remain the
only person to tackle such projects in the future.
— David
