[GHC] #8143: File name module name mismatch in Parser.hs in HEAD

[GHC]

#8143: File name module name mismatch in Parser.hs in HEAD
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        Reporter:  carter            |            Owner:
            Type:  bug               |           Status:  new
        Priority:  normal            |        Milestone:
       Component:  Compiler          |          Version:  7.7
      Resolution:                    |         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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Comment (by carter):

 Seems to be that the Parser.hs file generated by Parser.y.pp  has some
 leading white space on its CPP pragmas


 {{{
  #if __GLASGOW_HASKELL__ >= 707
 -- Required on x86 to avoid the register allocator running out of
 -- stack slots when compiling this module with -fPIC -dynamic.
 {-# OPTIONS_GHC -fcmm-sink #-}
  #endif

 }}}

 If I change it to

 {{{
 #if __GLASGOW_HASKELL__ >= 707
 -- Required on x86 to avoid the register allocator running out of
 -- stack slots when compiling this module with -fPIC -dynamic.
 {-# OPTIONS_GHC -fcmm-sink #-}
 #endif

 }}}

 the build works

 The offending original code  seems to be this:

 {{{
 -- CPP tricks because we want the directives in the output of the
 -- first CPP pass.
 --
 -- Clang note, 6/17/2013 by aseipp: It is *extremely* important (for
 -- some reason) that there be a line of whitespace between the two
 -- definitions here, and the subsequent use of __IF_GHC_77__ - this
 -- seems to be a bug in clang or something, where having the line of
 -- whitespace will make the preprocessor correctly format the rendered
 -- lines in the 'two step' CPP pass. No, this is not a joke.
 #define __IF_GHC_77__ #if __GLASGOW_HASKELL__ >= 707
 #define __ENDIF__ #endif

 __IF_GHC_77__
 -- Required on x86 to avoid the register allocator running out of
 -- stack slots when compiling this module with -fPIC -dynamic.
 {-# OPTIONS_GHC -fcmm-sink #-}
 __ENDIF__

 }}}

 I'm trying a test build of Current HEAD where my host c compiler is
 gcc-4.8, and my ./configure with-gcc=clang where I put the CPP in
 directly. (i'm not sure why we need the __IF_GHC_77__ and __ENDIF__)

 alternatively, to prevent the leading whitespace,
 something like

 {{{
 #define __IF_GHC_77__  /
 #if __GLASGOW_HASKELL__ >= 707

 }}}

 might make sense?

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8143#comment:2>
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