[GHC] #3843: Merge plugins into HEAD

[GHC]

#3843: Merge plugins into HEAD
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    Reporter:  dreixel           |        Owner:  simonpj     
        Type:  task              |       Status:  new         
    Priority:  normal            |    Milestone:              
   Component:  Compiler          |      Version:  6.13        
    Keywords:                    |   Difficulty:              
          Os:  Unknown/Multiple  |     Testcase:              
Architecture:  Unknown/Multiple  |      Failure:  None/Unknown
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Comment(by simonpj):

 A core-to-core plugin pass does just what it sounds like: transforms the
 program to a new program.  I don't know a good way for a plugin to monitor
 what ''another'' core-to-core pass is doing; in this case the rewrite
 rules, which are fired by the Simplifier.  It's not clear to me how to do
 that.  What would it mean to "figure out what was rewritten and where",
 when the whole program is being radically transformed?

 It's a good goal, but I don't currently know how to achieve it.

 There is a (slightly moribund) core-to-core pass, enabled by `-frule-
 check`, that looks for places where a rule nearly (but not quite) applies,
 and reports those.  So it might be a start for what you want. The code is
 in `Rules.ruleCheckProgram`.

 Simon

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/3843#comment:4>
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