[GHC] #9780: dep_orphs in Dependencies redundantly records type family orphans

[GHC]

#9780: dep_orphs in Dependencies redundantly records type family orphans
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        Reporter:  ezyang            |                   Owner:
            Type:  bug               |                  Status:  new
        Priority:  normal            |               Milestone:  7.10.1
       Component:  Compiler          |                 Version:  7.9
      Resolution:                    |                Keywords:
Operating System:  Unknown/Multiple  |            Architecture:
 Type of failure:  Compile-time      |  Unknown/Multiple
  performance bug                    |               Test Case:
      Blocked By:                    |                Blocking:
 Related Tickets:                    |  Differential Revisions:
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Changes (by thomie):

 * status:  closed => new
 * resolution:  fixed =>


Comment:

 I now realize this bug report is not just about changing the invalid
 comment, but also about performing the optimization mentioned in the
 title. In `main/HscTypes.hs`:
 {{{
          , dep_orphs  :: [Module]
                         -- ^ Transitive closure of orphan modules (whether
                         -- home or external pkg).
                         --
                         -- (Possible optimization: don't include family
                         -- instance orphans as they are anyway included in
                         -- 'dep_finsts'.  But then be careful about code
                         -- which relies on dep_orphs having the complete
 list!)
 }}}

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9780#comment:2>
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