[GHC] #13055: Adding INLINABLE pragma causes GHC panic

[GHC]

#13055: Adding INLINABLE pragma causes GHC panic
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        Reporter:  mpickering        |                Owner:
            Type:  bug               |               Status:  closed
        Priority:  high              |            Milestone:  8.2.1
       Component:  Compiler          |              Version:  8.0.1
      Resolution:  fixed             |             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 simonpj):

 I'm very confused about this.  The comment at the top of `GHC.Base` says
 {{{
 NOTA BENE: Do NOT use ($) anywhere in this module! The type of ($) is
 slightly magical (it can return unlifted types), and it is wired in.
 But, it is also *defined* in this module, with a non-magical type.
 GHC gets terribly confused (and *hangs*) if you try to use ($) in this
 module, because it has different types in different scenarios.

 This is not a problem in general, because the type ($), being wired in, is
 not
 written out to the interface file, so importing files don't get confused.
 The problem is only if ($) is used here. So don't!
 }}}
 (It should jolly well have a `Note` heading so we can refer to it.)

 But I don't understand that. The wired-in definition should override the
 local one, even in the module it is defined in.  I'd love a better
 understanding of what goes wrong.

 But life is short, I suppose.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13055#comment:7>
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