January 2016 - ghc-tickets

[GHC] #11520: GHC falls into a hole
by GHC 11 Feb '16

11 Feb '16

#11520: GHC falls into a hole -------------------------------------+------------------------------------- Reporter: bgamari | Owner: Type: bug | Status: new Priority: normal | Milestone: 8.0.1 Component: Compiler | Version: 8.0.1-rc1 (Type checker) | 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: -------------------------------------+------------------------------------- {{{#!hs {-# LANGUAGE RankNTypes, PolyKinds, TypeInType, GADTs, UndecidableSuperClasses #-} module Play where import GHC.Types hiding (TyCon) data TyCon (a :: k) = TyCon data TypeRep (a :: k) where TypeCon :: forall (a :: k). TyCon a -> TypeRep k -> TypeRep a TypeApp :: forall k1 k2 (a :: k1 -> k2) (b :: k1). TypeRep a -> TypeRep b -> TypeRep (a b) class Typeable k => Typeable (a :: k) where typeRep :: TypeRep a data Compose (f :: k1 -> *) (g :: k2 -> k1) (a :: k2) = Compose (f (g a)) composeTyCon :: TyCon Compose composeTyCon = TyCon Fingerprint "Compose" instance (Typeable f, Typeable (g :: k), Typeable k) => Typeable (Compose f g) where typeRep = TypeApp (TypeApp (TypeCon composeTyCon typeRep) typeRep) typeRep instance (Typeable f, Typeable g, Typeable a) => Typeable (Compose f g a) where typeRep = TypeApp (TypeApp (TypeApp (TypeCon composeTyCon typeRep) typeRep) typeRep) typeRep }}} fails with {{{ λ> :load Bug.hs [1 of 1] Compiling Play ( Bug.hs, interpreted ) ghc: panic! (the 'impossible' happened) (GHC version 8.1.20160122 for x86_64-unknown-linux): fvProv falls into a hole {abet} Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11520> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11399: Ill-kinded instance head involving -XTypeInType can invoke GHC panic
by GHC 11 Feb '16

11 Feb '16

#11399: Ill-kinded instance head involving -XTypeInType can invoke GHC panic -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.1 (Type checker) | Keywords: TypeInType | Operating System: Unknown/Multiple Architecture: | Type of failure: Compile-time Unknown/Multiple | crash Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- This code: {{{#!hs {-# LANGUAGE FlexibleInstances, TypeInType #-} module FvProvFallsIntoAHole where import Data.Kind newtype UhOh (k :: * -> *) (a :: k *) = UhOh (k *) instance Functor k => Functor (UhOh k) where }}} produces this GHC panic: {{{ $ /opt/ghc/head/bin/ghc FvProvFallsIntoAHole.hs [1 of 1] Compiling FvProvFallsIntoAHole ( FvProvFallsIntoAHole.hs, FvProvFallsIntoAHole.o ) ghc: panic! (the 'impossible' happened) (GHC version 8.1.20160108 for x86_64-unknown-linux): fvProv falls into a hole {aq6} Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11399> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10734: pprint of ‘let’ inside ‘do’ prints invalid Haskell
by GHC 10 Feb '16

10 Feb '16

#10734: pprint of ‘let’ inside ‘do’ prints invalid Haskell -------------------------------------+------------------------------------- Reporter: Fuuzetsu | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Template | Version: 7.10.2 Haskell | Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Revisions: | -------------------------------------+------------------------------------- On GHC 7.10.1 {{{#!hs Prelude Language.Haskell.TH Language.Haskell.TH.Ppr> pprint <$> runQ [| do { let { x = 5 }; return x; } |] "do {let x_0 = 5; GHC.Base.return x_0}" }}} The let binding inside the resulting {{{do}}} should be inside curly braces too -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10734> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10022: Clean up GHC.RTS.Flags
by GHC 09 Feb '16

09 Feb '16

#10022: Clean up GHC.RTS.Flags -------------------------------------+------------------------------------- Reporter: | Owner: thoughtpolice | Status: new Type: bug | Milestone: 7.12.1 Priority: normal | Version: 7.10.1-rc1 Component: | Operating System: Unknown/Multiple libraries/base | Type of failure: None/Unknown Keywords: | Blocked By: Architecture: | Related Tickets: #9970 Unknown/Multiple | Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- There's some cleanup to do for `GHC.RTS.Flags`, based on the comments in https://ghc.haskell.org/trac/ghc/ticket/5364#comment:11 -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10022> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11465: Eliminate check_lifted check in TcValidity
by GHC 08 Feb '16

08 Feb '16

#11465: Eliminate check_lifted check in TcValidity -------------------------------------+------------------------------------- Reporter: simonpj | Owner: Type: bug | 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: -------------------------------------+------------------------------------- In `TcValidity`, when checking for valid types, we had a long-standing test, embodied in a local function called `check_lifted`, which checked that a number of places had a lifted type of kind `*` and not an unlifted one of kind `#`. But that test is out-dated now; the kind system does the job. So this ticket is to remove the `check_lifted` test. See the discussion in #11120, starting at comment:19. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11465> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11163: New exhaustiveness checker breaks T5642
by GHC 08 Feb '16

08 Feb '16

#11163: New exhaustiveness checker breaks T5642 -------------------------------------+------------------------------------- Reporter: bgamari | Owner: Type: bug | Status: new Priority: high | Milestone: 8.0.1 Component: Compiler | Version: 7.10.2 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Compile-time Unknown/Multiple | performance bug Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- The new exhaustiveness checker drastically increases compile time of the `T5642` testcase. From the profile it appears that a great deal of time is being spent evaluating `Check.mkPmId.occname`, {{{ COST CENTRE MODULE %time %alloc mkPmId.occname Check 73.7 16.9 mkOneConFull Check 3.4 10.2 deSugar HscMain 2.8 14.8 mkOneConFull.arguments Check 2.5 5.5 pmTraverse Check 1.6 0.8 mkOneConFull.subst1 Check 1.5 5.9 wrapK.go Check 1.5 5.9 cMatcher Check 1.2 2.7 canEvVar TcCanonical 1.0 3.4 }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11163> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11161: New exhaustiveness checker breaks concurrent/prog001
by GHC 08 Feb '16

08 Feb '16

#11161: New exhaustiveness checker breaks concurrent/prog001 -------------------------------------+------------------------------------- Reporter: bgamari | Owner: Type: bug | Status: new Priority: normal | Milestone: 8.0.1 Component: Compiler | Version: 7.10.2 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Compile-time Unknown/Multiple | performance bug Test Case: | Blocked By: concurrent/prog001 | Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- The new exhaustiveness checker appears to allocate until the machine runs out of memory while compiling the `concurrent/prog001` testcase. In particular it stalls while desugaring the `Thread` module. The fact that this module contains non-trivial pattern matching, coupled with the compiler gets stuck in `Desugar`, and the fact that I've noted other performance issues with the new exhaustiveness checker (see #10711) leads me to believe that this patch is to blame. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11161> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11160: New exhaustiveness checker breaks ghcirun004
by GHC 08 Feb '16

08 Feb '16

#11160: New exhaustiveness checker breaks ghcirun004 -------------------------------------+------------------------------------- Reporter: bgamari | Owner: Type: bug | Status: new Priority: high | Milestone: Component: Compiler | Version: 7.10.2 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Compile-time Unknown/Multiple | performance bug Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- The new exhaustiveness checker has broken `tests/ghci/should_run/ghcirun004`, which now hangs in desugaring. If one removes all but a few hundred of `foo`'s equations in the test things return to sanity. It appears that the compile time is scaling non-linearly with the number of equations, ||= no. equations =||= compile wall time =|| || 150 || 0.4 s || || 250 || 0.89 s || || 300 || 1.22 s || || 350 || 1.85 s || || 400 || 2.65 s || || 500 || 4.86 s || || 550 || 6.60 s || || 600 || 8.65 s || || 650 || 10.27 s || || 700 || 12.84 s || || 1000 || 38.51 s || -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11160> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11303: Pattern matching against sets of strings sharing a prefix blows up pattern checker
by GHC 08 Feb '16

08 Feb '16

#11303: Pattern matching against sets of strings sharing a prefix blows up pattern checker -------------------------------------+------------------------------------- Reporter: bgamari | Owner: gkaracha Type: bug | Status: new Priority: normal | Milestone: 8.0.1 Component: Compiler | Version: 7.11 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Compile-time Unknown/Multiple | performance bug Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- hvr stumbled upon this issue while attempting to bootstrap GHC with GHC HEAD. In so doing he found that GHC HEAD required more than 10 GB of memory while compiling `genprimopcode` (and never completed). It appears that this blow-up is due to the new pattern checker. In particular it appears that the pattern checker is affected quite adversely by sets of patterns sharing a prefix. For instance, this example, {{{#!hs import System.Environment main :: IO () main = do args <- getArgs print $ case head args of "--primop-primop-info" -> "turtle" "--primop-tag" -> "asdf" "--primop-list" -> "casdhf" "--primop-vector-uniques" -> "this" "--primop-vector-tys" -> "is" "--primop-vector-tys-exports" -> "silly" "--primop-vector-tycons" -> "hmmm" "--make-haskell-wrappers" -> "123512" "--make-haskell-source" -> "as;dg" "--make-latex-doc" -> "adghiw" _ -> error "Should not happen, known_args out of sync?" }}} As written GHC requires over ten gigabytes of heap and several minutes to compile the example. If one perform `s/--primop-//` to this example it takes 500ms to compile. Alternatively, if on replace the first `-` in each of the `--primop` strings with a unique character (thus breaking the shared prefixes) compilation time is a bit shy of a second. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11303> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11491: GHC 10.7.3 panic while executing 'stack upgrade' on Mac OSX El Capitan
by GHC 07 Feb '16

07 Feb '16

#11491: GHC 10.7.3 panic while executing 'stack upgrade' on Mac OSX El Capitan ----------------------------------------+--------------------------------- Reporter: hienqnguyen | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.3 Keywords: | Operating System: MacOS X Architecture: Unknown/Multiple | Type of failure: None/Unknown Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: ----------------------------------------+--------------------------------- {{{ /Users/tdoan$ stack upgrade Fetched package index. Populated index cache. stack-1.0.2: download Warning: /private/var/folders/wl/8jbs0c_w8xj_5z0059bpz1v80000gn/T/stack- upgrade8446/stack-1.0.2/stack.yaml: Unrecognized field in ImageOptsMonoid: containers Cabal-1.22.6.0: copying precompiled package SHA-1.6.4.2: copying precompiled package ansi-terminal-0.6.2.3: copying precompiled package auto-update-0.1.3: copying precompiled package base-orphans-0.4.5: copying precompiled package base16-bytestring-0.1.1.6: copying precompiled package ansi-wl-pprint-0.6.7.3: download ansi-wl-pprint-0.6.7.3: configure base64-bytestring-1.0.0.1: copying precompiled package byteable-0.1.1: copying precompiled package bytestring-builder-0.10.6.0.0: copying precompiled package cereal-0.4.1.1: copying precompiled package cryptohash-0.11.6: copying precompiled package data-default-class-0.0.1: copying precompiled package ansi-wl-pprint-0.6.7.3: build dlist-0.7.1.2: copying precompiled package extra-1.4.2: download extra-1.4.2: configure extra-1.4.2: build ansi-wl-pprint-0.6.7.3: copy/register file-embed-0.0.9: download file-embed-0.0.9: configure file-embed-0.0.9: build file-embed-0.0.9: copy/register extra-1.4.2: copy/register filelock-0.1.0.1: download filelock-0.1.0.1: configure generics-sop-0.2.0.0: download filelock-0.1.0.1: build generics-sop-0.2.0.0: configure generics-sop-0.2.0.0: build filelock-0.1.0.1: copy/register gitrev-1.2.0: download gitrev-1.2.0: configure gitrev-1.2.0: build gitrev-1.2.0: copy/register hourglass-0.2.9: copying precompiled package ieee754-0.7.6: download ieee754-0.7.6: configure ieee754-0.7.6: build ieee754-0.7.6: copy/register Progress: 21/136 -- While building package generics-sop-0.2.0.0 using: /Users/tdoan/.stack/setup-exe-cache/x86_64-osx/setup-Simple- Cabal-1.22.5.0-ghc-7.10.3 --builddir=.stack- work/dist/x86_64-osx/Cabal-1.22.5.0 build --ghc-options " -ddump-hi -ddump-to-file" Process exited with code: ExitFailure 1 Logs have been written to: /private/var/folders/wl/8jbs0c_w8xj_5z0059bpz1v80000gn/T/stack- upgrade8446/stack-1.0.2/.stack-work/logs/generics-sop-0.2.0.0.log Configuring generics-sop-0.2.0.0... Building generics-sop-0.2.0.0... Preprocessing library generics-sop-0.2.0.0... [ 1 of 13] Compiling Generics.SOP.Sing ( src/Generics/SOP/Sing.hs, .stack-work/dist/x86_64-osx/Cabal-1.22.5.0/build/Generics/SOP/Sing.o ) [ 2 of 13] Compiling Generics.SOP.Constraint ( src/Generics/SOP/Constraint.hs, .stack- work/dist/x86_64-osx/Cabal-1.22.5.0/build/Generics/SOP/Constraint.o ) [ 3 of 13] Compiling Generics.SOP.BasicFunctors ( src/Generics/SOP/BasicFunctors.hs, .stack- work/dist/x86_64-osx/Cabal-1.22.5.0/build/Generics/SOP/BasicFunctors.o ) [ 4 of 13] Compiling Generics.SOP.Classes ( src/Generics/SOP/Classes.hs, .stack- work/dist/x86_64-osx/Cabal-1.22.5.0/build/Generics/SOP/Classes.o ) [ 5 of 13] Compiling Generics.SOP.NP ( src/Generics/SOP/NP.hs, .stack-work/dist/x86_64-osx/Cabal-1.22.5.0/build/Generics/SOP/NP.o ) [ 6 of 13] Compiling Generics.SOP.Metadata ( src/Generics/SOP/Metadata.hs, .stack- work/dist/x86_64-osx/Cabal-1.22.5.0/build/Generics/SOP/Metadata.o ) [ 7 of 13] Compiling Generics.SOP.Dict ( src/Generics/SOP/Dict.hs, .stack-work/dist/x86_64-osx/Cabal-1.22.5.0/build/Generics/SOP/Dict.o ) [ 8 of 13] Compiling Generics.SOP.NS ( src/Generics/SOP/NS.hs, .stack-work/dist/x86_64-osx/Cabal-1.22.5.0/build/Generics/SOP/NS.o ) [ 9 of 13] Compiling Generics.SOP.GGP ( src/Generics/SOP/GGP.hs, .stack-work/dist/x86_64-osx/Cabal-1.22.5.0/build/Generics/SOP/GGP.o ) [10 of 13] Compiling Generics.SOP.Universe ( src/Generics/SOP/Universe.hs, .stack- work/dist/x86_64-osx/Cabal-1.22.5.0/build/Generics/SOP/Universe.o ) [11 of 13] Compiling Generics.SOP.TH ( src/Generics/SOP/TH.hs, .stack-work/dist/x86_64-osx/Cabal-1.22.5.0/build/Generics/SOP/TH.o ) [12 of 13] Compiling Generics.SOP.Instances ( src/Generics/SOP/Instances.hs, .stack- work/dist/x86_64-osx/Cabal-1.22.5.0/build/Generics/SOP/Instances.o ) ghc: panic! (the 'impossible' happened) (GHC version 7.10.3 for x86_64-apple-darwin): Loading temp shared object failed: dlopen(/var/folders/wl/8jbs0c_w8xj_5z0059bpz1v80000gn/T/ghc8794_0/libghc_70.dylib, 5): Library not loaded: /usr/local/opt/ghc/lib/ghc-7.10.3/templ_GJPvtLC64aA4c1Jl10o2qt /libHStemplate-haskell-2.10.0.0-GJPvtLC64aA4c1Jl10o2qt-ghc7.10.3.dylib Referenced from: /var/folders/wl/8jbs0c_w8xj_5z0059bpz1v80000gn/T/ghc8794_0/libghc_70.dylib Reason: image not found Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug /Users/tdoan$ stack --version Version 1.0.0 x86_64 }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11491> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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