[GHC] #14036: GHCi HEAD segfaults upon startup with a prof build

[GHC]

#14036: GHCi HEAD segfaults upon startup with a prof build
-------------------------------------+-------------------------------------
        Reporter:  RyanGlScott       |                Owner:  (none)
            Type:  bug               |               Status:  patch
        Priority:  highest           |            Milestone:  8.4.1
       Component:  Compiler          |              Version:  8.3
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  GHCi crash        |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D3983
       Wiki Page:                    |
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Comment (by David Feuer <David.Feuer@…>):

 In [changeset:"60a3f11ff4b7e239a273498812fd9d31f6775726/ghc"
 60a3f11f/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="60a3f11ff4b7e239a273498812fd9d31f6775726"
 Fix pointer tagging mistake

 f9c6d53fe997f1c560cda6f346f4b201711df37c led to #14036. The
 problem turned out to be rather simple: the `obj` pointer was
 being tagged using `obj + arity`. Because this is C, that's done
 with *pointer arithmetic*, which is not at all what we want. Add
 appropriate casts.

 Reviewers: austin, bgamari, erikd, simonmar

 Reviewed By: bgamari

 Subscribers: rwbarton, thomie

 GHC Trac Issues: #14036

 Differential Revision: https://phabricator.haskell.org/D3983
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14036#comment:3>
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