[GHC] #8493: Can't compile happy + ghc with clang's CPP

[GHC]

#8493: Can't compile happy + ghc with clang's CPP
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        Reporter:  maxs                 |            Owner:
            Type:  bug                  |           Status:  new
        Priority:  highest              |        Milestone:  7.8.1
       Component:  libraries (other)    |          Version:  7.7
      Resolution:                       |         Keywords:  happy clang
Operating System:  MacOS X              |     Architecture:
 Type of failure:  Building GHC failed  |  Unknown/Multiple
       Test Case:                       |       Difficulty:  Unknown
        Blocking:                       |       Blocked By:
                                        |  Related Tickets:
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Comment (by maxs):

 I don't think we have a problem with indentation if you use happy 1.18.10
 or happy HEAD (2cfc3b70cd). If you use happy 1.19 to compile happy, you
 may have indentation problems with clang. But HEAD fixed that.

 We do however have a problem with some lines with preprocessor "comments".

 Happy Version 1.18.10 can compile happy HEAD (with clang).
 But if you then try to compile a happy program (like GHC or happy HEAD)
 with happy HEAD, it will error on:

 {{{
 <built-in>:2:2: Not in scope: `#'
 }}}

 Which is from the happy processed files. They look like:

 {{{
 {-# LINE 1 "templates/GenericTemplate.hs" #-}
 # 1 "templates/GenericTemplate.hs"
 # 1 "<built-in>" 1
 # 1 "templates/GenericTemplate.hs" 2
 -- $Id: GenericTemplate.hs,v 1.26 2005/01/14 14:47:22 simonmar Exp $
 ...
 }}}

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8493#comment:5>
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