[GHC] #8528: Preprocessor issues building GHC HEAD on Mavericks

[GHC]

#8528: Preprocessor issues building GHC HEAD on Mavericks
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        Reporter:  guest                |            Owner:
            Type:  bug                  |           Status:  new
        Priority:  high                 |        Milestone:
       Component:  Compiler             |          Version:  7.7
      Resolution:                       |         Keywords:  clang
Operating System:  MacOS X              |     Architecture:  x86_64 (amd64)
 Type of failure:  Building GHC failed  |       Difficulty:  Unknown
       Test Case:                       |       Blocked By:
        Blocking:                       |  Related Tickets:  #8480
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Comment (by nkpart):

 Turns out that rolling back alex was a red herring. I needed to make sure
 that alex was being built with GCC, not with clang.

 Alex can be built with clang (pretending to be gcc), but if you later call
 it with gcc (actually being gcc) then it fails in the way you see above.

 So at the moment, do not build alex with clang-as-gcc, then later call it
 with gcc-as-gcc.

 The diff in the Lexer.hs file that I posted above are actually the changes
 that arise when you switch from a GCC-compiled Alex (what I labeled 3.1.0)
 to a Clang-compiled Alex (3.1.2).

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8528#comment:10>
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