June 2018 - ghc-tickets

[GHC] #11610: Remove IEThingAll constructor from IE datatype
by GHC 12 Jan '19

12 Jan '19

#11610: Remove IEThingAll constructor from IE datatype -------------------------------------+------------------------------------- Reporter: mpickering | Owner: Type: task | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.3 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- It seems that now `IEThingWith` can include a wildcard that the `IEThingAll` constructor is a special case. I'm not sure how involved this would be but it seems worth doing. {{{ | IEThingAll (Located name) -- ^ Class/Type plus all methods/constructors -- -- - 'ApiAnnotation.AnnKeywordId's : 'ApiAnnotation.AnnOpen', -- 'ApiAnnotation.AnnDotdot','ApiAnnotation.AnnClose', -- 'ApiAnnotation.AnnType' -- For details on above see note [Api annotations] in ApiAnnotation -- See Note [Located RdrNames] in HsExpr | IEThingWith (Located name) IEWildcard [Located name] [Located (FieldLbl name)] -- ^ Class/Type plus some methods/constructors -- and record fields; see Note [IEThingWith] -- - 'ApiAnnotation.AnnKeywordId's : 'ApiAnnotation.AnnOpen', -- 'ApiAnnotation.AnnClose', -- 'ApiAnnotation.AnnComma', -- 'ApiAnnotation.AnnType' -- For details on above see note [Api annotations] in ApiAnnotation }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11610> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 4

[GHC] #13587: addTopDecls fails with typed Template Haskell
by GHC 12 Jan '19

12 Jan '19

#13587: addTopDecls fails with typed Template Haskell -------------------------------------+------------------------------------- Reporter: tmcdonell | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Template | Version: 8.2.1-rc1 Haskell | Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- The following untyped Template Haskell works as expected: {{{#!hs --- AddTopDecls.hs --- {-# LANGUAGE TemplateHaskell #-} {-# LANGUAGE QuasiQuotes #-} module AddTopDecls where import Language.Haskell.TH import Language.Haskell.TH.Syntax importDoubleToDouble :: String -> ExpQ importDoubleToDouble fname = do n <- newName fname d <- forImpD CCall unsafe fname n [t|Double -> Double|] addTopDecls [d] varE n --- Main.hs --- {-# LANGUAGE TemplateHaskell #-} module Main where import AddTopDecls main :: IO () main = do let sin' = $(importDoubleToDouble "sin") cos' = $(importDoubleToDouble "cos") -- print (sin' 0) print (cos' pi) }}} However it fails if I convert to the equivalent typed version: {{{#!hs --- AddTopDecls.hs --- {-# LANGUAGE TemplateHaskell #-} {-# LANGUAGE QuasiQuotes #-} module AddTopDecls where import Language.Haskell.TH import Language.Haskell.TH.Syntax importDoubleToDouble :: String -> Q (TExp (Double -> Double)) importDoubleToDouble fname = do n <- newName fname d <- forImpD CCall unsafe fname n [t|Double -> Double|] addTopDecls [d] unsafeTExpCoerce (varE n) --- Main.hs --- {-# LANGUAGE TemplateHaskell #-} module Main where import AddTopDecls main :: IO () main = do let sin' = $$(importDoubleToDouble "sin") cos' = $$(importDoubleToDouble "cos") -- print (sin' 0) print (cos' pi) }}} With the error: {{{ > ghci Main.hs -ddump-splices GHCi, version 8.2.0.20170404: http://www.haskell.org/ghc/ :? for help [1 of 2] Compiling AddTopDecls ( AddTopDecls.hs, interpreted ) [2 of 2] Compiling Main ( Main.hs, interpreted ) Main.hs:9:19-44: Splicing expression importDoubleToDouble "sin" ======> sin_a4s2 Main.hs:1:1: Splicing top-level declarations added with addTopDecls ======> foreign import ccall unsafe "sin" Main.sin :: Double -> Double Main.hs:9:19: error: • GHC internal error: ‘sin_a4s2’ is not in scope during type checking, but it passed the renamer tcl_env of environment: [a4dl :-> Identifier[sin'::t1, TopLevelLet [] False], a4dm :-> Identifier[cos'::t1, TopLevelLet [] False], r4cW :-> Identifier[main::IO (), TopLevelLet]] • In the expression: sin_a4s2 In the result of the splice: $importDoubleToDouble "sin" To see what the splice expanded to, use -ddump-splices In the Template Haskell splice $$(importDoubleToDouble "sin") | 9 | let sin' = $$(importDoubleToDouble "sin") | ^^^^^^^^^^^^^^^^^^^^^^^^^^ }}} Tested with 7.10.3, 8.0.2, and 8.2.0-rc1. Unfortunately I can't use untyped TH in my real use case, so if you have any suggestions for a workaround that would also be great. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13587> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 12

[GHC] #10946: Typed hole inside typed Template Haskell bracket causes panic
by GHC 12 Jan '19

12 Jan '19

#10946: Typed hole inside typed Template Haskell bracket causes panic -------------------------------------+------------------------------------- Reporter: jstolarek | Owner: Type: bug | Status: new Priority: high | Milestone: 8.0.1 Component: Template | Version: 7.10.1 Haskell | Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Compile-time Unknown/Multiple | crash Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | -------------------------------------+------------------------------------- When I say: {{{#!hs m :: a -> a m x = $$([||_||]) }}} I get: {{{ T10946.hs:47:13:ghc: panic! (the 'impossible' happened) (GHC version 7.10.1 for x86_64-unknown-linux): No skolem info: a_apJ[sk] }}} This happens both with GHC 7.10.1 and latest HEAD (e2b579e8d77357e8b36f57d15daead101586ac8e). -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10946> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 19

[GHC] #12103: Typed Template Haskell missing many utilities provided by untyped variant
by GHC 12 Jan '19

12 Jan '19

#12103: Typed Template Haskell missing many utilities provided by untyped variant -------------------------------------+------------------------------------- Reporter: bgamari | Owner: Type: bug | Status: new Priority: normal | Milestone: 8.2.1 Component: Template | Version: 8.0.1 Haskell | Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- Currently typed TH feels a bit second-class as it lacks a number of handy utilities which are provided in the untyped case. In my brief look at this I encountered the following, {{{#!hs type TExpQ a = Q (TExp a) stringT :: String -> TExpQ String trueT, false :: TExpQ Bool }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12103> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 5

[GHC] #10945: Typed Template Haskell splices broken in HEAD (7.11)
by GHC 12 Jan '19

12 Jan '19

#10945: Typed Template Haskell splices broken in HEAD (7.11) -------------------------------------+------------------------------------- Reporter: jstolarek | Owner: Type: bug | Status: new Priority: high | Milestone: 8.0.1 Component: Template | Version: 7.11 Haskell | Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | -------------------------------------+------------------------------------- In the latest HEAD (e2b579e8d77357e8b36f57d15daead101586ac8e) when I say: {{{#!hs $$(return [ SigD (mkName "m") (ForallT [PlainTV (mkName "a")] [] (AppT (AppT ArrowT (VarT (mkName "a"))) (VarT (mkName "a")))) , FunD (mkName "m") [Clause [VarP (mkName "x")] (NormalB (VarE (mkName "x"))) []] ]) }}} I get: {{{ ghc-stage2: panic! (the 'impossible' happened) (GHC version 7.11.20151007 for x86_64-unknown-linux): runRnSplice $$(return [SigD (mkName "m") (ForallT [PlainTV (mkName "a")] [] (AppT (AppT ArrowT (VarT (mkName "a"))) (VarT (mkName "a")))), FunD (mkName "m") [Clause [VarP (mkName "x")] (NormalB (VarE (mkName "x"))) []]]) }}} This code compiles correctly in GHC 7.10.1. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10945> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 13

[GHC] #11452: Typed Template Haskell sneakily allows impredicativity
by GHC 12 Jan '19

12 Jan '19

#11452: Typed Template Haskell sneakily allows impredicativity -------------------------------------+------------------------------------- Reporter: goldfire | Owner: goldfire Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- The following module is accepted: {{{#!hs {-# LANGUAGE ExplicitForAll, TemplateHaskell #-} module Bug where impred :: forall a. a -> a impred = $$( [|| \x -> x ||] ) }}} But that requires an intermediate `TExp (forall a. a -> a)`. Will fix in ongoing work. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11452> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 6

[GHC] #10949: Document typed Template Haskell
by GHC 12 Jan '19

12 Jan '19

#10949: Document typed Template Haskell -------------------------------------+------------------------------------- Reporter: goldfire | Owner: Type: bug | Status: new Priority: high | Milestone: 8.0.1 Component: Template | Version: 7.10.2 Haskell | Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Documentation Unknown/Multiple | bug Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | -------------------------------------+------------------------------------- As far as I can tell, typed Template Haskell is completely missing from the manual. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10949> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 3

[GHC] #14838: missing "incomplete-patterns" warning for TH-generated functions
by GHC 12 Jan '19

12 Jan '19

#14838: missing "incomplete-patterns" warning for TH-generated functions -------------------------------------+------------------------------------- Reporter: gelisam | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Template | Version: 8.2.2 Haskell | Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Incorrect Unknown/Multiple | error/warning at compile-time Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- "incomplete-patterns" warnings are generated for TH-generated case expressions, but not for TH-generated functions, so the behaviour is inconsistent. For example: {{{#!hs {-# LANGUAGE TemplateHaskell #-} module Lib where import Language.Haskell.TH qIncompleteCase :: Q [Dec] qIncompleteCase = [d| incompleteCase :: Bool -> () incompleteCase b = case b of True -> () |] qIncompleteFunction :: Q [Dec] qIncompleteFunction =[d| incompleteFunction :: Bool -> () incompleteFunction True = () |] }}} {{{#!hs {-# LANGUAGE TemplateHaskell #-} module Bug where import Lib $qIncompleteCase $qIncompleteFunction incompleteCase' :: Bool -> () incompleteCase' b = case b of True -> () incompleteFunction' :: Bool -> () incompleteFunction' True = () }}} When compiling the above two files with `-Wall`, GHC 8.2.2 produces an "incomplete-patterns" warning for `qIncompleteCase`, `incompleteCase'`, and `incompleteFunction'`, but not for `qIncompleteFunction`. I would prefer to get a warning for `qIncompleteFunction` as well. My use case is the [https://hackage.haskell.org/package/surjective surjective] package, in which I intentionally generate code which produces warnings in order to warn the user about corresponding issues in their code. I could generate [https://github.com/gelisam/surjective/blob/master/src/Surjective.hs#L158-L1… better error messages] if GHC generated warnings for TH-generated functions as well. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14838> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 13

[GHC] #14271: ghci hangs with -fexternal-interpreter -prof
by GHC 10 Jan '19

10 Jan '19

#14271: ghci hangs with -fexternal-interpreter -prof ----------------------------------------+------------------------------- Reporter: AndreasK | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: GHCi | Version: 8.2.1 Keywords: | Operating System: Windows Architecture: Unknown/Multiple | Type of failure: GHCi crash Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: ----------------------------------------+------------------------------- {{{ ghci -fexternal-interpreter -prof GHCi, version 8.2.1: http://www.haskell.org/ghc/ :? for help Access violation in generated code when reading 00000001001e0418 }}} * The address remains the same between reruns (and reinstalls) of ghc. * Closing the hanging process leaves the launched ghc active in the background. * The directory I launch ghci from doesn't seem to matter. * I have only tried it on my desktop so far (Win10/Skylake) -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14271> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 13

[GHC] #14576: Internal error when compiling TH code with profiling on Windows
by GHC 10 Jan '19

10 Jan '19

#14576: Internal error when compiling TH code with profiling on Windows -------------------------------------+------------------------------------- Reporter: lazac | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: GHC API | Version: 8.2.1 Keywords: | Operating System: Unknown/Multiple Architecture: x86_64 | Type of failure: Compile-time (amd64) | crash or panic Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- When using the GHC API with this minimal example, compiled with profiling enabled: {{{#!hs module Main where import GHC import GHC.Paths ( libdir ) main = runGhc (Just libdir) $ do env <- getSession dflags <- getSessionDynFlags setSessionDynFlags dflags target <- guessTarget "A.hs" Nothing setTargets [target] load LoadAllTargets }}} Invoking the main executable: {{{ testprof }}} While A.hs contains a TH splice: {{{#!hs {-# LANGUAGE TemplateHaskell #-} module A where $(return []) }}} The compiler crashes: {{{ testprof.exe: internal error: IMAGE_REL_AMD64_ADDR32[NB]: High bits are set in 10e6109d0 for .text (GHC version 8.2.1 for x86_64_unknown_mingw32) Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug This application has requested the Runtime to terminate it in an unusual way. Please contact the application's support team for more information. }}} The walkaround is to use -fexternal-interpreter, in that case, the crash does not happen. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14576> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 5