[GHC] #12115: CoreLint error in safe program

[GHC]

#12115: CoreLint error in safe program
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        Reporter:  osa1              |                Owner:
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.0.1
      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:                    |
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Comment (by Simon Peyton Jones <simonpj@…>):

 In [changeset:"e9e61f18a548b70693f4ccd245bc56335c94b498/ghc"
 e9e61f18/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="e9e61f18a548b70693f4ccd245bc56335c94b498"
 Reduce special-casing for nullary unboxed tuple

 When we built the kind of a nullary unboxed tuple, we said, in
 TysWiredIn.mk_tuple:

     res_rep | arity == 0 = voidRepDataConTy
                   -- See Note [Nullary unboxed tuple] in Type
             | otherwise  = unboxedTupleRepDataConTy

 But this is bogus.  The Note deals with what the 'unarise' transformation
 does, and up to that point it's simpler and more uniform to treat
 nullary unboxed tuples the same as all the others.

 Nicer now.  And it fixes the Lint error in Trac #12115
 }}}

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12115#comment:1>
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