[GHC] #8467: Stack overflow when optimizing recursive newtype

20 Oct 2013

      #8467: Stack overflow when optimizing recursive newtype
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       Reporter:  goldfire          |             Owner:
           Type:  bug               |            Status:  new
       Priority:  normal            |         Milestone:
      Component:  Compiler          |           Version:  7.7
       Keywords:                    |  Operating System:  Unknown/Multiple
   Architecture:  Unknown/Multiple  |   Type of failure:  None/Unknown
     Difficulty:  Unknown           |         Test Case:
     Blocked By:                    |          Blocking:
Related Tickets:                    |
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 I have

 {{{
 module Bug where

 newtype Void = Void Void

 data Decision a = Disproved (a -> Void)

 foo :: () -> Decision Int
 foo _ = Disproved (\_ -> undefined)
 }}}

 When I

 {{{
...
ghc -O Bug.hs
 }}}
I get

 {{{
 [1 of 1] Compiling Bug              ( Bug.hs, Bug.o )
 stack overflow: use +RTS -K<size> to increase it
 }}}

 The module compiles fine without `-O`. This was tested on 7.7.20131011.

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Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8467
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