[GHC] #7143: ghc-7.6.0.20120810-x86_64-windows.exe -> ghc can't figure out LLVM version

[GHC]

#7143: ghc-7.6.0.20120810-x86_64-windows.exe -> ghc can't figure out LLVM version
-------------------------------------------------+-------------------------
        Reporter:  cetinsert                     |            Owner:
            Type:  bug                           |  dterei
        Priority:  high                          |           Status:  new
       Component:  Compiler (LLVM)               |        Milestone:  7.8.1
      Resolution:                                |          Version:
Operating System:  Windows                       |  7.6.1-rc1
 Type of failure:  Incorrect warning at          |         Keywords:  llvm
  compile-time                                   |     Architecture:
       Test Case:                                |  Unknown/Multiple
        Blocking:                                |       Difficulty:
                                                 |  Unknown
                                                 |       Blocked By:
                                                 |  Related Tickets:
-------------------------------------------------+-------------------------

Comment (by schyler):

 Using the HP ghc on Windows you get an error like this (even if llc and
 opt are directly callable from the *same* command line):

 {{{
 <no location info>:
     Warning: Couldn't figure out LLVM version!
              Make sure you have installed LLVM
 }}}

 This occurs with all versions of llvm.

 ghc --info is interesting:
 {{{
  [("Project name","The Glorious Glasgow Haskell Compilation System")
  ,("GCC extra via C opts"," -fwrapv")
  ,("C compiler command","$topdir/../mingw/bin/gcc.exe")
  ,("C compiler flags"," -fno-stack-protector  -Wl,--hash-size=31 -Wl
 ,--reduce-memory-overheads")
  ,("ar command","$topdir/../mingw/bin/ar.exe")
  ,("ar flags","q")
  ,("ar supports at file","YES")
  ,("touch command","$topdir/touchy.exe")
  ,("dllwrap command","$topdir/../mingw/bin/dllwrap.exe")
  ,("windres command","$topdir/../mingw/bin/windres.exe")
  ,("perl command","$topdir/../perl/perl.exe")
  ,("target os","OSMinGW32")
  ,("target arch","ArchX86")
  ,("target word size","4")
  ,("target has GNU nonexec stack","False")
  ,("target has .ident directive","True")
  ,("target has subsections via symbols","False")
  ,("LLVM llc command","")
  ,("LLVM opt command","")
  ,("Project version","7.6.3")
  ,("Booter version","7.4.1")
  ,("Stage","2")
  ,("Build platform","i386-unknown-mingw32")
  ,("Host platform","i386-unknown-mingw32")
  ,("Target platform","i386-unknown-mingw32")
  ,("Have interpreter","YES")
  ,("Object splitting supported","YES")
  ,("Have native code generator","YES")
  ,("Support SMP","YES")
  ,("Unregisterised","NO")
  ,("Tables next to code","YES")
  ,("RTS ways","l debug  thr thr_debug thr_l thr_p dyn debug_dyn thr_dyn
 thr_debug_dyn")
  ,("Leading underscore","YES")
  ,("Debug on","False")
  ,("LibDir","C:\\Program Files (x86)\\Haskell Platform\\2013.2.0.0\\lib")
  ,("Global Package DB","C:\\Program Files (x86)\\Haskell
 Platform\\2013.2.0.0\\lib\\package.conf.d")
  ,("Gcc Linker flags","[\"-Wl,--hash-size=31\",\"-Wl,--reduce-memory-
 overheads\"]")
  ,("Ld Linker flags","[\"--hash-size=31\",\"--reduce-memory-overheads\"]")
  ]
 }}}

 For some reason the commands to interface with llc/opt are empty. I was
 able to work around it by doing this;

 `alias ghc-llvm="ghc -pgmlo opt -pgmlc llc -fllvm"`

 ... and then using `ghc-llvm` whenever I wanted to use llvm. This works
 perfectly.

 The 64-bit GHC from GHC HQ has the same problem, and the same workaround
 works for me.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7143#comment:8>
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