- ghc-tickets - Haskell.org

[GHC] #10968: Type hole cause bad type checking
by GHC 13 Jan '16

13 Jan '16

#10968: Type hole cause bad type checking -------------------------------------+------------------------------------- Reporter: ndtimofeev | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.2 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: -------------------------------------+------------------------------------- I've tried to compile that incorrect code on ghc-7.10.2 linux x86_64: {{{#!hs import Control.Monad.Reader type Tst m = ReaderT () (ReaderT Int m) f :: Monad m => Tst m () f = return () f1 :: ReaderT () m () -> ReaderT () m () f1 ev = f >> _ >> ev main :: IO () main = print $ runReaderT (f1 (return ())) () }}} But тypechecker does not reject f1 and have that: {{{ [1 of 1] Compiling Main ( /home/ndtimofeev/tst.hs, /home/ndtimofeev/tst.o ) ghc: panic! (the 'impossible' happened) (GHC version 7.10.2 for x86_64-unknown-linux): StgCmmEnv: variable not found $dFunctor_aYS local binds for: f_rsZ Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} If switch hole to undefined, i have normal typechecking error. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10968> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 4

Re: [GHC] #4220: EmptyDataDecls + DeriveFunctor == Panic!
by GHC 12 Jan '16

12 Jan '16

#4220: EmptyDataDecls + DeriveFunctor == Panic! -------------------------------------+------------------------------------- Reporter: conal | Owner: simonpj Type: bug | Status: closed Priority: normal | Milestone: 7.0.1 Component: Compiler | Version: 6.12.3 Resolution: fixed | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: Compile-time | Test Case: crash | deriving/should_compile/T4220 Blocked By: | Blocking: Related Tickets: #4302 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by thomie): * related: => #4302 Comment: commit 6efa3901fd6f1583fb654bd3659e88702dfd579a {{{ Author: simonpj(a)microsoft.com <unknown> Date: Thu Aug 12 13:13:19 2010 +0000 Fix Trac #4220 For deriving Functor, Foldable, Traversable with empty data cons I just generate a null equation f _ = error "urk" There are probably more lurking (eg Enum) but this will do for now. }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/4220#comment:9> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 0

Re: [GHC] #4302: Impossible when deriving empty data declaration
by GHC 12 Jan '16

12 Jan '16

#4302: Impossible when deriving empty data declaration -------------------------------------+------------------------------------- Reporter: mitar | Owner: Type: bug | Status: closed Priority: normal | Milestone: 7.4.1 Component: Compiler | Version: 6.12.3 Resolution: fixed | Keywords: Operating System: Linux | Architecture: x86_64 | (amd64) Type of failure: None/Unknown | Test Case: | deriving/should_compile/T4302 Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by thomie): commit 2fc5aa708982a414235d3aff68dea4329b546063 {{{ Author: simonpj(a)microsoft.com <unknown> Date: Mon Sep 13 17:03:55 2010 +0000 Fix Trac #4302, plus a little refactoring }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/4302#comment:3> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 0

Re: [GHC] #8040: installed include/HsVersions.h wants to #include "../includes/ghcautoconf.h"
by GHC 12 Jan '16

12 Jan '16

#8040: installed include/HsVersions.h wants to #include "../includes/ghcautoconf.h" -------------------------------------+------------------------------------- Reporter: hvr | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Build System | Version: 7.6.3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by angerman): This has also come up in the `shaking-up-ghc`[1] project, when trying to move the build products out of the source tree[2]. ---- [1]: https://github.com/snowleopard/shaking-up-ghc [2]: https://github.com/snowleopard/shaking-up-ghc/issues/113 -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8040#comment:2> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 0

[GHC] #11411: GHC allows you to quantify variables over TYPE 'Unlifted (a.k.a, #)
by GHC 12 Jan '16

12 Jan '16

#11411: GHC allows you to quantify variables over TYPE 'Unlifted (a.k.a, #) -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.1 (Type checker) | Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: GHC accepts Unknown/Multiple | invalid program Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- This should be disallowed, so [https://phabricator.haskell.org/D1757 sayeth goldfire]: {{{ $ inplace/bin/ghc-stage2 --interactive GHCi, version 8.1.20160109: http://www.haskell.org/ghc/ :? for help λ> :set -XKindSignatures λ> import GHC.Types λ> data Wat (a :: TYPE 'Unlifted) = Wat a λ> :i Wat data Wat (a :: #) = Wat a -- Defined at <interactive>:3:1 λ> :set -XMagicHash λ> :t Wat 1# Wat 1# :: Wat GHC.Prim.Int# λ> :t Wat 'a'# Wat 'a'# :: Wat GHC.Prim.Char# }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11411> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 2

[GHC] #11360: Test "termination" doesn't pass with reversed uniques
by GHC 12 Jan '16

12 Jan '16

#11360: Test "termination" doesn't pass with reversed uniques -------------------------------------+------------------------------------- Reporter: niteria | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: GHC rejects Unknown/Multiple | valid program Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- It fails with (full trace https://phabricator.haskell.org/P80) {{{ *** Core Lint errors : in result of Tidy Core *** <no location info>: warning: In the expression: ReplaceApply @ k_a18o1Q @ (Apply t1_X18o1T t2_X18o1O) @ n_a18o1O @ (Apply r1_X18o1Q r2_X18o1M) @ r2_X18o1M @ t2_X18o1O @ r1_X18o1Q @ t1_X18o1T @~ (<Apply t1_X18o1T t2_X18o1O>_N :: Apply t1_X18o1T t2_X18o1O ~# Apply t1_X18o1T t2_X18o1O) @~ (<Apply r1_X18o1Q r2_X18o1M>_N :: Apply r1_X18o1Q r2_X18o1M ~# Apply r1_X18o1Q r2_X18o1M) dt_a18nR6 dt_a18nR5 Argument value doesn't match argument type: Fun type: (Apply r1_X18o1Q t2_X18o1O ~# Apply t1_X18o1T t2_X18o1O, Apply r1_X18o1Q r2_X18o1M ~# Apply r1_X18o1Q r2_X18o1M) => Replace k_a18o1Q t1_X18o1T n_a18o1O r1_X18o1Q -> Replace k_a18o1Q t2_X18o1O n_a18o1O r2_X18o1M -> Replace k_a18o1Q (Apply r1_X18o1Q t2_X18o1O) n_a18o1O (Apply r1_X18o1Q r2_X18o1M) Arg type: Apply t1_X18o1T t2_X18o1O ~# Apply t1_X18o1T t2_X18o1O Arg: CO: <Apply t1_X18o1T t2_X18o1O>_N }}} Steps to reproduce: 1. Add line `TEST_HC_OPTS += -dinitial-unique=16777000 -dunique-increment=-1` after line `TEST_HC_OPTS = -fforce-recomp -dcore-lint -dcmm-lint -dno-debug-output -no-user-$(GhcPackageDbFlag) -rtsopts $(EXTRA_HC_OPTS)` in `mk/test.mk` 2. `make TESTS=termination` I suspect this is the same problem I'm running at https://mail.haskell.org/pipermail/ghc-devs/2016-January/010902.html, since the same change to `substTyWith` makes the test pass for me. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11360> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 5

[GHC] #11387: Typecasting using type application syntax
by GHC 12 Jan '16

12 Jan '16

#11387: Typecasting using type application syntax -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: Type: feature | Status: new request | Priority: normal | Milestone: Component: Compiler | Version: Keywords: | Operating System: Unknown/Multiple TypeApplications | Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: #11350 Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- I created #11350 to allow visible (static) type applications in patterns. I had a [https://ghc.haskell.org/trac/ghc/ticket/11350#comment:2 thought] about translating non-parametric type applications in patterns as a runtime type check (`Typeable`) and decided to create a ticket in case it made any sense. Example: {{{#!hs doubleWhenInt :: forall a. Typeable a => a -> a doubleWhenInt x = case eqT @Int @a of Just Refl -> x + x Nothing -> x -- Becomes… doubleWhenInt :: Typeable a => a -> a doubleWhenInt @Int n = n + n doubleWhenInt @_ x = x }}} Thoughts? -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11387> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 3

[GHC] #11390: GHC does not warn about redundant equations
by GHC 12 Jan '16

12 Jan '16

#11390: GHC does not warn about redundant equations -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.1 Keywords: warnings | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- Given the Phab:D1535 effort in GHC 8.0 I was curious how an example from Richard's post [https://typesandkinds.wordpress.com/2015/09/09/what-are- type-families/ What are type families?] would fare: {{{ % ghci -Wall -XTypeFamilies -ignore-dot-ghci GHCi, version 8.1.20160105: http://www.haskell.org/ghc/ :? for help Prelude> :set +m Prelude> type family F1 a where Prelude| F1 Int = Bool Prelude| Prelude> let Prelude| sillyId :: F1 Char -> F1 Char Prelude| sillyId x = x Prelude| Prelude> }}} This seems to fly, even though as the blog post noted, ”[...] sillyId can’t ever be called on a value.” Isn't the clause redundant and should be defined using `EmptyCase` (#2431) as `sillyId x = case x of {}`? It seems GHC doesn't care that the pattern match in the equation `absurd2 _ = ...` is redundant either: {{{#!hs data Void absurd1 :: Void -> a; absurd1 = \case absurd2 :: Void -> a absurd2 _ = undefined }}} Is this intended or known behaviour? -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11390> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 15

[GHC] #11356: GHC panic
by GHC 12 Jan '16

12 Jan '16

#11356: GHC panic -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.1 (Type checker) | Keywords: | Operating System: Linux Architecture: x86 | Type of failure: Compile-time | crash Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- The attached file causes GHC (version 8.1.20160102) panic. I tried shrinking, attached code is bogus at this point. Interestingly inlining the type synonym `T = Nat` into Category's superclass context fixes the panic, and causes a regular error. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11356> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 9

Re: [GHC] #4243: Make a proper options parser for the RTS
by GHC 11 Jan '16

11 Jan '16

#4243: Make a proper options parser for the RTS -------------------------------------+------------------------------------- Reporter: igloo | Owner: Type: task | Status: new Priority: normal | Milestone: 8.0.1 Component: Runtime System | Version: 6.13 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: 7535 Related Tickets: #9839 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by simonmar): I'd prefer not to add a dependency on an external tool if possible. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/4243#comment:21> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 0