[GHC] #793: Use gcc's libffi to replace Adjustor.c and ByteCodeFFI.hs?

[GHC]

#793: Use gcc's libffi to replace Adjustor.c and ByteCodeFFI.hs?
----------------------------+-----------------------------------------------
 Reporter:  simonmar        |          Owner:  simonmar        
     Type:  task            |         Status:  new             
 Priority:  normal          |      Milestone:  6.8 branch      
Component:  Runtime System  |        Version:  6.4.1           
 Severity:  normal          |     Resolution:                  
 Keywords:                  |     Difficulty:  Moderate (1 day)
 Testcase:  N/A             |   Architecture:  Unknown         
       Os:  Unknown         |  
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Comment (by simonmar):

 Replying to [comment:8 igloo]:
 > I don't think we should bundle it. It's the sort of thing where more
 obscure platforms need the latest version, and we don't another thing we
 have to make sure we keep up-to-date. Also, for the common case (including
 Windows users) it isn't necessary to have it, as the existing code can be
 used instead.

 I agree, except that I've just done a bit of digging and libffi would fix:

  * #1288 (stdcall in GHCi on Windows)
  * #738 (SELinux)
  * #631 (FFI in GHCi unregisterised)

 For #738, we could pinch the code from `libffi` which works around the
 issue (the license is unrestrictive).  For #1288, I'd rather just use
 `libffi` than implement it myself, but that means requiring `libffi` on
 Windows.  For #631, I assume it's not a problem to require `libffi` for
 unregisterised builds.

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/793#comment:9>
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