#8215: Out of scope with `-dcore-lint` and derived instances in GHCi ------------------------------------+------------------------------------- Reporter: nomeata | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.6.3 Keywords: | Operating System: Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+------------------------------------- At revision 9e2e84e01cbf2bc1da1fc7260709f63687206d76 (current HEAD), I observe this failure: {{{ $ ./inplace/bin/ghc-stage2 --interactive GHCi, version 7.7.20130902: http://www.haskell.org/ghc/ :? for help Loading package ghc-prim ... linking ... done. Loading package integer-gmp ... linking ... done. Loading package base ... linking ... done. Prelude> newtype Age = Age Int deriving Show Prelude> newtype Bar = Bar Age deriving Show Prelude> Bar (Age 1)) <interactive>:4:12: parse error on input `)' Prelude> Bar (Age 1) Bar (Age 1) Prelude> Leaving GHCi. [jojo@kirk:3] Mo, der 02.09.2013 um 16:47 Uhr Keep Smiling :-) ~/build/haskell/ghc $ ./inplace/bin/ghc-stage2 --interactive -dcore-lint GHCi, version 7.7.20130902: http://www.haskell.org/ghc/ :? for help Loading package ghc-prim ... linking ... done. Loading package integer-gmp ... linking ... done. Loading package base ... linking ... done. Prelude> newtype Age = Age Int deriving Show Prelude> newtype Bar = Bar Age deriving Show *** Core Lint errors : in result of Desugar (after optimization) *** <no location info>: Warning: In the expression: GHC.Show.showsPrec @ :Interactive.Age :Interactive.$fShowAge (GHC.Types.I# 11) (ds_dq3 `cast` (:Interactive.NTCo:Bar[0] :: :Interactive.Bar ~# :Interactive.Age)) :Interactive.$fShowAge :: GHC.Show.Show :Interactive.Age [LclIdX[DFunId], Str=DmdType] is out of scope *** Offending Program *** Rec { $cshowsPrec_apH :: GHC.Types.Int -> :Interactive.Bar -> GHC.Show.ShowS [LclId, Str=DmdType] $cshowsPrec_apH = \ (a_apF :: GHC.Types.Int) (ds_dq3 :: :Interactive.Bar) -> GHC.Show.showParen (GHC.Classes.>= @ GHC.Types.Int GHC.Classes.$fOrdInt a_apF (GHC.Types.I# 11)) (GHC.Base.. @ GHC.Base.String @ GHC.Base.String @ GHC.Base.String (GHC.Show.showString (GHC.CString.unpackCString# "Bar "#)) (GHC.Show.showsPrec @ :Interactive.Age :Interactive.$fShowAge (GHC.Types.I# 11) (ds_dq3 `cast` (:Interactive.NTCo:Bar[0] :: :Interactive.Bar ~# :Interactive.Age)))) :Interactive.$fShowBar [InlPrag=[ALWAYS] CONLIKE] :: GHC.Show.Show :Interactive.Bar [LclIdX[DFunId], Str=DmdType, Unf=DFun: \ -> GHC.Show.D:Show TYPE :Interactive.Bar $cshowsPrec_apH $cshow_apS $cshowList_apU] :Interactive.$fShowBar = GHC.Show.D:Show @ :Interactive.Bar $cshowsPrec_apH $cshow_apS $cshowList_apU $cshowList_apU [Occ=LoopBreaker] :: [:Interactive.Bar] -> GHC.Show.ShowS [LclId, Str=DmdType] $cshowList_apU = GHC.Show.showList__ @ :Interactive.Bar (GHC.Show.showsPrec @ :Interactive.Bar :Interactive.$fShowBar (GHC.Types.I# 0)) $cshow_apS [Occ=LoopBreaker] :: :Interactive.Bar -> GHC.Base.String [LclId, Str=DmdType] $cshow_apS = GHC.Show.$dmshow @ :Interactive.Bar :Interactive.$fShowBar end Rec } *** End of Offense *** <no location info>: Compilation had errors *** Exception: ExitFailure 1 }}} I do not observe this in GHC. I’ll write a test case for this. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8215 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler