[GHC] #9370: unfolding info as seen when building a module depends on flags in a previously-compiled module

[GHC]

#9370: unfolding info as seen when building a module depends on flags in a
previously-compiled module
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        Reporter:  carter            |                Owner:  richardfung
            Type:  bug               |               Status:  new
        Priority:  high              |            Milestone:  8.2.1
       Component:  Compiler          |              Version:  7.8.3
      Resolution:                    |             Keywords:  newcomer,
                                     |  Inlining
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Compile-time      |  Unknown/Multiple
  performance bug                    |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #8635             |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by richardfung):

 Not really sadly.. I've been just trying to understand all the code.

 I started looking from where --make starts, trying to go down to where the
 ModInfo is actually generated.

 I see that mkIface_ generates the [IfaceDecl] that gets passed to
 addFingerprints which eventually returns the ModIface which we save and I
 believe reuse, but that's the farthest I've gotten; I still don't know
 where IfaceIdInfo is set to NoInfo.

 At least.. I think that's what's happening?

 Given the fact I haven't even started looking at the second part of this
 problem, checking when to inline, I'm beginning to wonder if I'm in over
 my head!

 Any advice would certainly be appreciated.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9370#comment:26>
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