T12622 fails in ghci way

T12622, which is intended to test StaticPointers, fails in the GHCi way with a core lint warning,

*** Core Lint errors : in result of Float out(FOS {Lam = Just 0,                                                                                              
                                                   Consts = True,                                                                                        
                                                   OverSatApps = False}) ***                                                                                 
<no location info>: warning:                                                                                                                               
    In the expression: >>=                                                                                                                               
                         @ IO                                                                                                                                
                         $fMonadIO                                                                                                                              
                         @ (Bool -> Bool)                                                                                                                           
                         @ ()                                                                                                                                   
                         (break<10>(s_a1DF) lvl_s3bD)                                                                                                               
                         lvl_s3bE                                                                                             
    s_a1DF :: StaticPtr (Bool -> Bool)                                                                                            
    [LclId,                                                                                                                   
     Unf=Unf{Src=<vanilla>, TopLvl=False, Value=False, ConLike=False,
             WorkFree=False, Expandable=False,
             Guidance=IF_ARGS [] 70 0}] is out of scope
*** Offending Program ***
g :: Bool
[LclIdX]
g = break<15>() True

$trModule_s3b7 :: Addr#
[LclId]
$trModule_s3b7 = "main"#

$trModule_s3b6 :: TrName
[LclId]
$trModule_s3b6 = TrNameS $trModule_s3b7

$trModule_s3b9 :: Addr#
[LclId]
$trModule_s3b9 = "Main"#

$trModule_s3b8 :: TrName
[LclId]
$trModule_s3b8 = TrNameS $trModule_s3b9

$trModule :: Module
[LclIdX]
$trModule = Module $trModule_s3b6 $trModule_s3b8

lvl_s3bj :: Addr#
[LclId]
lvl_s3bj = "error"#

lvl_s3bk :: [Char]
[LclId]
lvl_s3bk = unpackCString# lvl_s3bj

lvl_s3bl :: Addr#
[LclId]
lvl_s3bl = "main"#

lvl_s3bm :: [Char]
[LclId]
lvl_s3bm = unpackCString# lvl_s3bl

lvl_s3bn :: Addr#
[LclId]
lvl_s3bn = "Main"#

lvl_s3bo :: [Char]
[LclId]
lvl_s3bo = unpackCString# lvl_s3bn
lvl_s3bp :: Addr#
[LclId]
lvl_s3bp = "T12622.hs"#

lvl_s3bq :: [Char]
[LclId]
lvl_s3bq = unpackCString# lvl_s3bp

lvl_s3br :: Int
[LclId]
lvl_s3br = I# 21#

lvl_s3bs :: Int
[LclId]
lvl_s3bs = I# 14#

lvl_s3bt :: Int
[LclId]
lvl_s3bt = I# 21#

lvl_s3bu :: Int
[LclId]
lvl_s3bu = I# 64#

lvl_s3bv :: SrcLoc
[LclId]
lvl_s3bv
  = SrcLoc
      lvl_s3bm lvl_s3bo lvl_s3bq lvl_s3br lvl_s3bs lvl_s3bt lvl_s3bu

lvl_s3bw :: ([Char], SrcLoc)
[LclId]
lvl_s3bw = (lvl_s3bk, lvl_s3bv)

$dIP_s3bc :: CallStack
[LclId]
$dIP_s3bc = pushCallStack lvl_s3bw emptyCallStack

lvl_s3bx :: Addr#
[LclId]
lvl_s3bx = "couldn't find "#

lvl_s3by :: [Char]
[LclId]
lvl_s3by = unpackCString# lvl_s3bx

lookupKey :: forall a. StaticPtr a -> IO a
[LclIdX, Arity=1]
lookupKey
  = \ (@ a_a23X) (p_X1DX :: StaticPtr a_a23X) ->                              
      break<8>(p_X1DX)                              
      >>=                                                                     
        @ IO          
        $fMonadIO
        @ (Maybe (StaticPtr a_a23X))
        @ a_a23X             
        (break<1>(p_X1DX)           
         unsafeLookupStaticPtr              
           @ a_a23X (break<0>(p_X1DX) staticKey @ a_a23X p_X1DX))
        (\ (ds_d3as :: Maybe (StaticPtr a_a23X)) ->
           case ds_d3as of {                                     
             Nothing ->                            
               break<7>(p_X1DX)  
               error   
                 @ 'LiftedRep                                
                 @ (IO a_a23X)
                 ($dIP_s3bc                                  
                  `cast` (Sym (N:IP[0] <"callStack">_N <CallStack>_N)
                          :: (CallStack :: *) ~R# ((?callStack::CallStack) :: Constraint)))
                 (break<6>(p_X1DX)                                   
                  ++                                                                       
                    @ Char        
                    lvl_s3by
                    (break<5>(p_X1DX)
                     show   
                       @ StaticPtrInfo
                       $fShowStaticPtrInfo
                       (break<4>(p_X1DX) staticPtrInfo @ a_a23X p_X1DX)));
             Just p_a1DI ->               
               break<3>(p_a1DI)                                           
               return      
                 @ IO          
                 $fMonadIO
                 @ a_a23X 
                 (break<2>(p_a1DI) deRefStaticPtr @ a_a23X p_a1DI)
           })            
                                                                  
$dTypeable_s3bA :: TypeRep Bool
[LclId]                   
$dTypeable_s3bA = mkTrCon @ * @ Bool $tcBool ([] @ SomeTypeRep)
                            
s_s3bC :: StaticPtr (Bool -> Bool)                             
[LclId]                         
s_s3bC                            
  = case break<9>()             
         sg                  
           @ Bool                      
           ($dTypeable_s3bA                                      
            `cast` (Sym N:Typeable[0] <*>_N <Bool>_N
                    :: (TypeRep Bool :: *) ~R# (Typeable Bool :: Constraint)))
    of
    { T s_a38b ->
    s_a38b
    }

lvl_s3bD :: IO (Bool -> Bool)
[LclId]
lvl_s3bD = lookupKey @ (Bool -> Bool) s_s3bC

lvl_s3bE :: (Bool -> Bool) -> IO ()
[LclId]
lvl_s3bE
  = \ (f_a1DG :: Bool -> Bool) ->
      break<12>(f_a1DG)
      print @ Bool $fShowBool (break<11>(f_a1DG) f_a1DG True)

main :: IO ()
[LclIdX]
main
  = break<14>()
    break<13>(s_s3bC)
    >>=
      @ IO
      $fMonadIO
      @ (Bool -> Bool)
      @ ()
      (break<10>(s_a1DF) lvl_s3bD)
      lvl_s3bE

main :: IO ()
[LclIdX]
main = runMainIO @ () main

*** End of Offense ***


<no location info>: error:
Compilation had errors


*** Exception: ExitFailure 1
===== program output begins here
===== program output begins here

T12622:6:30: error:
    Not in scope: ‘Main.main’
    No module named ‘Main’ is imported.

Trac metadata

Trac field	Value
Version	8.1
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system
Architecture

changed milestone to %8.2.1

changed weight to 5

added Tbug Trac import labels

mentioned in commit 140a2d1c

Trac metadata

Trac field	Value
Related	- → #12622 (closed)

assigned to @facundominguez

Facundo, any ideas?

added StaticPointers label

assigned to @bgamari and unassigned @facundominguez

changed milestone to %8.2.2

changed weight to 7

I'm afraid this will need to wait for 8.2.2. Bumping priority to ensure I get to it.

Trac metadata

Trac field	Value
Priority	normal → high

I'll try to have a look at this on the plane to ICFP.

Trac metadata

Trac field	Value
Test case	- → T12622
Related	#12622 (closed) → #12356, #12622 (closed)

It looks like the cause here is that we started out with,

main :: IO ()
[LclIdX]
main
  = break<14>()
    let {
      s_a2kk :: StaticPtr (Bool -> Bool)
      [LclId]
      s_a2kk = ...
    } in
    break<13>(s_a2kk) 
    >>=
      @ IO
      GHC.Base.$fMonadIO
      @ (Bool -> Bool)
      @ ()
      (break<10>(s_a2kk) lookupKey @ (Bool -> Bool) s_a2kk)
      (...)

But then FloatOut floats s_a2kk out of the let giving it a new name (s_s3Sy) in the process. Somehow main then gets partially rewritten to,

main :: IO ()
[LclIdX]
main
  = break<14>()
    break<13>(s_s3Sy)
    >>=
      @ IO
      $fMonadIO
      @ (Bool -> Bool)
      @ ()
      (break<10>(s_a2kk) lvl_s3Sz)
      lvl_s3SA

Note the mention of s_a2kk remaining in break<10>, despite the fact that the reference in break<13> was correctly renamed.

Trac metadata

Trac field	Value
Differential revisions	- → D3920

mentioned in commit cd857dd4

added 1 deleted label

closed

removed 1 deleted label

Merged to ghc-8.2 as 9565e526.

Trac metadata

Trac field	Value
Resolution	Unresolved → ResolvedFixed

added compiler crash label

added Phigh label