[GHC] #9878: Static pointers in GHCi cause panic

[GHC]

#9878: Static pointers in GHCi cause panic
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              Reporter:  monoidal    |            Owner:  facundo.dominguez
                  Type:  bug         |           Status:  new
              Priority:  normal      |        Milestone:
             Component:  Compiler    |          Version:  7.9
            Resolution:              |         Keywords:
      Operating System:              |     Architecture:  Unknown/Multiple
  Unknown/Multiple                   |       Difficulty:  Unknown
       Type of failure:  GHCi crash  |       Blocked By:
             Test Case:              |  Related Tickets:
              Blocking:              |
Differential Revisions:              |
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Comment (by qnikst):

 There are 2 issues here:

 1.  That we don't support static pointers in ghci without fobject code.
 This is because module constructor that we are creating is not called, and
 because `speEntry` expressions that float out on desugarer phase is not
 instantiated by ghci.

 2. Also staticPtrKeys works incorrectly:
 a. it segfaults
 b. it memoizes it's result:

 {{{
 Prelude> :l Static
 Ok, modules loaded: Static.
 Prelude Static> length GHC.StaticPtr.currentStaticPtrKeys
 Prelude Static> length GHC.StaticPtr.staticPtrKeys
 staticPtrKeys    <-- debug ouput (function was called)
 0
 Prelude Static> f99  <-- forcing module loading
 True
 Prelude Static> length GHC.StaticPtr.staticPtrKeys
 0                    <-- no debug output (function was not called)
 Prelude Static> fmap length GHC.StaticPtr.currentStaticPtrKeys <-- IO
 variant
 staticPtrKeys        <-- debug output
 count: 1025
 1025
 }}}


 While I don't know an easy way to workaround 1st issue, I'll attach
 patches for the 2a and 2b.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9878#comment:8>
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