[GHC] #14946: GHC Calls CPP for HS with -undef

[GHC]

#14946: GHC Calls CPP for HS with -undef
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           Reporter:  Phyx-          |             Owner:  (none)
               Type:  bug            |            Status:  new
           Priority:  normal         |         Milestone:
          Component:  Compiler       |           Version:  8.2.2
           Keywords:                 |  Operating System:  Unknown/Multiple
       Architecture:                 |   Type of failure:  Incorrect result
  Unknown/Multiple                   |  at runtime
          Test Case:                 |        Blocked By:
           Blocking:                 |   Related Tickets:
Differential Rev(s):                 |         Wiki Page:
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 GHC Is calling the C preprocessor when processing HS files with `-undef`
 which unsets and compiler pre-defines.

 Essentially it means you cannot use any normal compiler defines to check
 for platform or intrinsics support.

 Is this really the intended behavior?

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14946>
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