[GHC] #14634: Add print stacktrace to exception handler in runtime system

[GHC]

#14634: Add print stacktrace to exception handler in runtime system
-------------------------------------+-------------------------------------
        Reporter:  flip101           |                Owner:  (none)
            Type:  feature request   |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.2.2
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by bgamari):

 > Could this handler be moved into the RTS so that i can stacktraces with
 exceptions just like with error?

 Not easily; `HasCallStack` is implemented entirely in Haskell and the RTS
 has no knowledge of if. Perhaps you could teach the compiler to put the
 "current" `CallStack` in a known location where the RTS can find it;
 however, at this point you arguably might as well just build with profilng
 as the latter is significantly less ad-hoc and likely only slightly less
 efficient.

 If the exception you are trying to identify is produced by code that you
 control then you could easily capture the `CallStack` from the the
 throwing context. This won't work for exceptions arising from, e.g.,
 `base`, however.

 One alternative that is currently unimplemented is to use DWARF stack
 unwinding to produce callstacks. In principle we have the ability to do
 this now (see wiki:DWARF/Status) and wiring it up to the exception
 handling subsystem is "merely" a matter of deciding an approach. See
 wiki:Exceptions/StackTraces and #12096 for some possible options.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14634#comment:1>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler