[GHC] #11047: Provide call stacks in GHCi

[GHC]

#11047: Provide call stacks in GHCi
-------------------------------------+-------------------------------------
        Reporter:  simonmar          |                Owner:  simonmar
            Type:  task              |               Status:  new
        Priority:  high              |            Milestone:  8.0.1
       Component:  GHCi              |              Version:  7.11
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #545, #4837       |  Differential Rev(s):  Phab:D1407
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by luite):

 GHCJSi also runs code in a separate process, which works in a similar way.
 I haven't merged it in the GHCJS master branch yet since it requires some
 horrible hacking (with lots of copy/paste) of the GHC bytecode interpreter
 to make it not try to load/run the BCO in its own process (and then
 segfault). GHCJSi is actually a lot simpler than GHCJS TH in terms of
 communication, it just sends new pieces of code to run, and there's an
 additional command to abort the running computation (with an async
 exception), however stepping/tracing/breakpoints are not yet supported
 (GHCJSi uses the usual code generator, there is no bytecode interpreter).

 The other reason for it still being experimental is that I haven't
 properly designed input/output yet, GHCJSi just prints all the stdout
 output from the underlying node.js process (or browser), which sometimes
 messes up the prompt. If anyone is interested in designing and
 implementing some proper process boundary protocol, let me know, I'd be
 happy to help (time permitting).

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11047#comment:9>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler