Re: [GHC] #15788: Core Lint error, from visible kind applications

20 Oct 2018

      #15788: Core Lint error, from visible kind applications
-------------------------------------+-------------------------------------
        Reporter:  Iceland_jack      |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.6.1
      Resolution:                    |             Keywords:  #12045
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------
Description changed by Iceland_jack:

Old description:
...
{{{#!hs
{-# Language RankNTypes       #-}
{-# Language GADTs            #-}
{-# Language TypeApplications #-}
{-# Language PolyKinds        #-}
{-# Options_GHC -dcore-lint #-}
import Data.Kind
data A :: forall k. Type where
 MkA :: A @k
}}}
this cute bug crashes under the [https://phabricator.haskell.org/D5229
visible kind application] diff, produces:
{{{
$ ghci -ignore-dot-ghci 545_bug.hs
GHCi, version 8.7.20181017: http://www.haskell.org/ghc/  :? for help
[1 of 1] Compiling Main             ( 545_bug.hs, interpreted )
*** Core Lint errors : in result of Tidy Core ***
<no location info>: warning:
    In the type ‘forall (k :: k_a1xN[sk:1]) k. A’
    @ k_a1xN[sk:1] is out of scope
*** Offending Program ***
$WMkA [InlPrag=INLINE[2]] :: forall (k :: k_a1xN[sk:1]) k. A
[GblId[DataConWrapper],
 Caf=NoCafRefs,
 Unf=Unf{Src=InlineStable, TopLvl=True, Value=True, ConLike=True,
         WorkFree=True, Expandable=True,
         Guidance=ALWAYS_IF(arity=0,unsat_ok=True,boring_ok=True)
         Tmpl= \ (@ (k_a1y5 :: k_a1xN[sk:1])) (@ k_X1xP) ->
                 MkA @ k_X1xP @ k_a1y5}]
$WMkA
  = \ (@ (k_a1y5 :: k_a1xN[sk:1])) (@ k_X1xP) ->
      MkA @ k_X1xP @ k_a1y5
$trModule1_r1zb :: Addr#
[GblId, Caf=NoCafRefs, Unf=OtherCon []]
$trModule1_r1zb = "main"#
$trModule2_r1zu :: TrName
[GblId, Caf=NoCafRefs, Unf=OtherCon []]
$trModule2_r1zu = TrNameS $trModule1_r1zb
$trModule3_r1zv :: Addr#
[GblId, Caf=NoCafRefs, Unf=OtherCon []]
$trModule3_r1zv = "Main"#
$trModule4_r1zw :: TrName
[GblId, Caf=NoCafRefs, Unf=OtherCon []]
$trModule4_r1zw = TrNameS $trModule3_r1zv
$trModule :: Module
[GblId, Caf=NoCafRefs, Unf=OtherCon []]
$trModule = Module $trModule2_r1zu $trModule4_r1zw
$krep_r1zx :: KindRep
[GblId, Caf=NoCafRefs, Unf=OtherCon []]
$krep_r1zx = KindRepVar 1#
$krep1_r1zy :: KindRep
[GblId, Caf=NoCafRefs, Unf=OtherCon []]
$krep1_r1zy = KindRepVar 0#
$tcA1_r1zz :: Addr#
[GblId, Caf=NoCafRefs, Unf=OtherCon []]
$tcA1_r1zz = "A"#
$tcA2_r1zA :: TrName
[GblId, Caf=NoCafRefs, Unf=OtherCon []]
$tcA2_r1zA = TrNameS $tcA1_r1zz
$tcA :: TyCon
[GblId, Unf=OtherCon []]
$tcA
  = TyCon
      16201120719427956884##
      13080046616073797921##
      $trModule
      $tcA2_r1zA
      2#
      krep$*
$krep2_r1zB :: [KindRep]
[GblId, Caf=NoCafRefs, Unf=OtherCon []]
$krep2_r1zB = : @ KindRep $krep1_r1zy ([] @ KindRep)
$krep3_r1zC :: [KindRep]
[GblId, Caf=NoCafRefs, Unf=OtherCon []]
$krep3_r1zC = : @ KindRep $krep_r1zx $krep2_r1zB
$krep4_r1zD :: KindRep
[GblId, Unf=OtherCon []]
$krep4_r1zD = KindRepTyConApp $tcA $krep3_r1zC
$tc'MkA1_r1zE :: Addr#
[GblId, Caf=NoCafRefs, Unf=OtherCon []]
$tc'MkA1_r1zE = "'MkA"#
$tc'MkA2_r1zF :: TrName
[GblId, Caf=NoCafRefs, Unf=OtherCon []]
$tc'MkA2_r1zF = TrNameS $tc'MkA1_r1zE
$tc'MkA :: TyCon
[GblId, Unf=OtherCon []]
$tc'MkA
  = TyCon
      1695572187443655535##
      16213897990811765752##
      $trModule
      $tc'MkA2_r1zF
      2#
      $krep4_r1zD
*** End of Offense ***

...
<no location info>: error:
Compilation had errors

...
*** Exception: ExitFailure 1
}}}
New description:

 {{{#!hs
 {-# Language RankNTypes       #-}
 {-# Language GADTs            #-}
 {-# Language TypeApplications #-}
 {-# Language PolyKinds        #-}

 {-# Options_GHC -dcore-lint #-}

 import Data.Kind

 data A :: forall k. Type where
  MkA :: A @k
 }}}

 this cute bug crashes under the [https://phabricator.haskell.org/D5229
 visible kind application] diff, produces:

 {{{
 $ ghci -ignore-dot-ghci 545_bug.hs
 GHCi, version 8.7.20181017: http://www.haskell.org/ghc/  :? for help
 [1 of 1] Compiling Main             ( 545_bug.hs, interpreted )
 *** Core Lint errors : in result of Tidy Core ***
 <no location info>: warning:
     In the type ‘forall (k :: k_a1xN[sk:1]) k. A’
     @ k_a1xN[sk:1] is out of scope
 *** Offending Program ***
 $WMkA [InlPrag=INLINE[2]] :: forall (k :: k_a1xN[sk:1]) k. A
 [GblId[DataConWrapper],
  Caf=NoCafRefs,
  Unf=Unf{Src=InlineStable, TopLvl=True, Value=True, ConLike=True,
          WorkFree=True, Expandable=True,
          Guidance=ALWAYS_IF(arity=0,unsat_ok=True,boring_ok=True)
          Tmpl= \ (@ (k_a1y5 :: k_a1xN[sk:1])) (@ k_X1xP) ->
                  MkA @ k_X1xP @ k_a1y5}]
 $WMkA
   = \ (@ (k_a1y5 :: k_a1xN[sk:1])) (@ k_X1xP) ->
       MkA @ k_X1xP @ k_a1y5

 $trModule1_r1zb :: Addr#
 [GblId, Caf=NoCafRefs, Unf=OtherCon []]
 $trModule1_r1zb = "main"#

 $trModule2_r1zu :: TrName
 [GblId, Caf=NoCafRefs, Unf=OtherCon []]
 $trModule2_r1zu = TrNameS $trModule1_r1zb

 $trModule3_r1zv :: Addr#
 [GblId, Caf=NoCafRefs, Unf=OtherCon []]
 $trModule3_r1zv = "Main"#

 $trModule4_r1zw :: TrName
 [GblId, Caf=NoCafRefs, Unf=OtherCon []]
 $trModule4_r1zw = TrNameS $trModule3_r1zv

 $trModule :: Module
 [GblId, Caf=NoCafRefs, Unf=OtherCon []]
 $trModule = Module $trModule2_r1zu $trModule4_r1zw

 $krep_r1zx :: KindRep
 [GblId, Caf=NoCafRefs, Unf=OtherCon []]
 $krep_r1zx = KindRepVar 1#

 $krep1_r1zy :: KindRep
 [GblId, Caf=NoCafRefs, Unf=OtherCon []]
 $krep1_r1zy = KindRepVar 0#

 $tcA1_r1zz :: Addr#
 [GblId, Caf=NoCafRefs, Unf=OtherCon []]
 $tcA1_r1zz = "A"#

 $tcA2_r1zA :: TrName
 [GblId, Caf=NoCafRefs, Unf=OtherCon []]
 $tcA2_r1zA = TrNameS $tcA1_r1zz

 $tcA :: TyCon
 [GblId, Unf=OtherCon []]
 $tcA
   = TyCon
       16201120719427956884##
       13080046616073797921##
       $trModule
       $tcA2_r1zA
       2#
       krep$*

 $krep2_r1zB :: [KindRep]
 [GblId, Caf=NoCafRefs, Unf=OtherCon []]
 $krep2_r1zB = : @ KindRep $krep1_r1zy ([] @ KindRep)

 $krep3_r1zC :: [KindRep]
 [GblId, Caf=NoCafRefs, Unf=OtherCon []]
 $krep3_r1zC = : @ KindRep $krep_r1zx $krep2_r1zB

 $krep4_r1zD :: KindRep
 [GblId, Unf=OtherCon []]
 $krep4_r1zD = KindRepTyConApp $tcA $krep3_r1zC

 $tc'MkA1_r1zE :: Addr#
 [GblId, Caf=NoCafRefs, Unf=OtherCon []]
 $tc'MkA1_r1zE = "'MkA"#

 $tc'MkA2_r1zF :: TrName
 [GblId, Caf=NoCafRefs, Unf=OtherCon []]
 $tc'MkA2_r1zF = TrNameS $tc'MkA1_r1zE

 $tc'MkA :: TyCon
 [GblId, Unf=OtherCon []]
 $tc'MkA
   = TyCon
       1695572187443655535##
       16213897990811765752##
       $trModule
       $tc'MkA2_r1zF
       2#
       $krep4_r1zD

 *** End of Offense ***

 <no location info>: error:
 Compilation had errors

 *** Exception: ExitFailure 1
 }}}

 Another example that fails

 {{{#!hs
 data
  Kl_kind :: forall (m :: k -> Type). Type where
  Kl      :: k -> Kl_kind @(m :: k -> Type)
 }}}

--

-- 
Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15788#comment:2
GHC http://www.haskell.org/ghc/
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