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[GHC] #13546: Kind error with type equality
by GHC 10 Apr '17

10 Apr '17

#13546: Kind error with type equality -------------------------------------+------------------------------------- Reporter: int-index | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 (Type checker) | Keywords: TypeInType | 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: -------------------------------------+------------------------------------- This code {{{#!hs {-# LANGUAGE TypeInType, TypeFamilies, GADTs, ConstraintKinds #-} import Data.Kind data Dict c where Dict :: c => Dict c data T (t :: k) type family UnT (a :: Type) :: k where UnT (T t) = t untt :: Dict (UnT (T "a") ~ "a") untt = Dict tunt :: Dict (T (UnT (T "a")) ~ T "a") tunt = Dict }}} fails with this error: {{{ tunt.hs:17:8: error: • Couldn't match kind ‘k’ with ‘GHC.Types.Symbol’ ‘k’ is a rigid type variable bound by the type signature for: tunt :: forall k. Dict T (UnT (T "a")) ~ T "a" at tunt.hs:16:1-38 When matching types UnT (T "a") :: k "a" :: GHC.Types.Symbol • In the expression: Dict In an equation for ‘tunt’: tunt = Dict • Relevant bindings include tunt :: Dict T (UnT (T "a")) ~ T "a" (bound at tunt.hs:17:1) | 17 | tunt = Dict | }}} Instead I would expect these reductions to take place: {{{ 1. T (UnT (T "a")) ~ T "a" 2. T "a" ~ T "a" 3. constraint satisfied (refl) }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13546> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #13556: "Building and using Win32 DLLs" is dead link
by GHC 10 Apr '17

10 Apr '17

#13556: "Building and using Win32 DLLs" is dead link -------------------------------------+------------------------------------- Reporter: varosi | Owner: (none) Type: bug | Status: new Priority: low | Milestone: Component: Documentation | Version: 8.0.2 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Documentation Unknown/Multiple | bug Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- https://wiki.haskell.org/GHC/Using_the_FFI Here the link "Building and using Win32 DLLs" is dead. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13556> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10613: Mechanism for checking that we only enter single-entry thunks once
by GHC 10 Apr '17

10 Apr '17

#10613: Mechanism for checking that we only enter single-entry thunks once -------------------------------------+------------------------------------- Reporter: bgamari | Owner: Type: feature | Status: new request | Milestone: Priority: normal | Version: 7.10.1 Component: Compiler | Operating System: Unknown/Multiple Keywords: | Type of failure: Other Architecture: | Blocked By: Unknown/Multiple | Related Tickets: Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- During this week's GHC call it came up that it would be nice to have a linting mechanism for verifying that we only enter single-entry thunks once, as currently this invariant appears to be completely unchecked. Currently we do not record whether a thunk is intended to be single-entry when we emit its code. Moreover, I don't believe there is any room for this left in the info table to record this fact. There are two ways I can think of accomodating this, * stealing a bit from the thunk type field * add a flags field to `StgDebugInfo` such that the lint requires the `debug` way As far as implementing the check itself, I think it should be rather straightforward. When we enter a thunk we simply want to check whether it is single-entry. If it is then we replace it with a special type of `BLACKHOLE`-like thunk which crashes the program (or merely emits a warning) on entry. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10613> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8816: Make SPARC registerised again.
by GHC 10 Apr '17

10 Apr '17

#8816: Make SPARC registerised again. -----------------------------------+--------------------------------- Reporter: kgardas | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.6.3 Keywords: | Operating System: Solaris Architecture: sparc | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | -----------------------------------+--------------------------------- It looks like recent GHC switched to unregisterised build on SPARC by default. This is kind of regression with the past GHCs where registerised builds were supported. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8816> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #13479: Core Lint issues during slowtest
by GHC 10 Apr '17

10 Apr '17

#13479: Core Lint issues during slowtest -------------------------------------+------------------------------------- Reporter: bgamari | Owner: (none) Type: bug | Status: new Priority: high | Milestone: 8.2.1 Component: Compiler | Version: 8.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Compile-time Unknown/Multiple | crash or panic Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- I'm am seeing Core Lint failurse from the `T5626` test, {{{ *** Core Lint errors : in result of Simplifier *** <no location info>: warning: [RHS of go_s54c :: [Int] -> (Int, Int, Int, Int)] idArity 2 exceeds typeArity 1: go_s54c }}} The relevant bits of the program are, {{{#!hs Rec { go_s54c [Occ=LoopBreaker] :: [Int] -> (Int, Int, Int, Int) [LclId, Arity=2, CallArity=2, Str=<B,U>b, Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True, WorkFree=True, Expandable=True, Guidance=NEVER}] go_s54c = \ (ds_X35o :: [Int]) -> case ds_X35o of { [] -> case lvl_s4Vm of wild_00 { }; : y_a34y [Dmd=<B,A>] ys_a34z [Dmd=<B,U>] -> go_s54c ys_a34z } end Rec } lvl_s54d :: (Int, Int, Int, Int) [LclId, Arity=1, Str=x, Unf=Unf{Src=<vanilla>, TopLvl=True, Value=True, ConLike=True, WorkFree=True, Expandable=True, Guidance=NEVER}] lvl_s54d = go_s54c ([] @ Int) }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13479> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #12793: Performs unaligned access on SPARC64
by GHC 09 Apr '17

09 Apr '17

#12793: Performs unaligned access on SPARC64 --------------------------------+---------------------------------------- Reporter: jrtc27 | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 Keywords: | Operating System: Linux Architecture: sparc | Type of failure: Building GHC failed Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: --------------------------------+---------------------------------------- (Filed under Architecture: sparc, since there's no sparc64 in the dropdown...) Trying to build GHC on sparc64 currently crashes with a SIGBUS (unaligned access). This is because sparc64 uses the C backend (only 32-bit sparc has native code gen), but is unaware that it can't perform unaligned accesses. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12793> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #5553: sendWakeup error in simple test program with MVars and killThread
by GHC 09 Apr '17

09 Apr '17

#5553: sendWakeup error in simple test program with MVars and killThread -------------------------------------+------------------------------------- Reporter: bit | Owner: (none) Type: bug | Status: new Priority: high | Milestone: 7.4.2 Component: Runtime System | Version: 8.0.1 Resolution: | Keywords: Operating System: Linux | Architecture: x86 Type of failure: Incorrect result | Test Case: at runtime | Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by rrnewton): I'm getting this error too, in a different program (on some runs only), with GHC 8.0.2. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/5553#comment:11> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #12396: Panic when specializing in another module
by GHC 08 Apr '17

08 Apr '17

#12396: Panic when specializing in another module -------------------------------------+------------------------------------- Reporter: crockeea | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 Keywords: | 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: -------------------------------------+------------------------------------- In the attached example (which requires `criterion` and `deepseq`), when compiled with `ghc -O2 -funfolding-use-threshold1000 Main.hs`, I get the following error on `Main.hs`: {{{ ghc: panic! (the 'impossible' happened) (GHC version 8.0.1 for x86_64-unknown-linux): StgCmmEnv: variable not found $d(%,%)_aaTF local binds for: $trModule $sfool $trModule1 $trModule2 $wlvl_rgY8 lvl_rgY9 lvl1_rgYa lvl3_rgYc lvl4_rgYd lvl5_rgYe lvl6_rgYf lvl7_rgYg lvl8_rgYh lvl9_rgYi lvl10_rgYj lvl11_rgYk lvl12_rgYl lvl13_rgYm lvl14_rgYn lvl15_rgYo lvl16_rgYp lvl17_rgYq lvl18_rgYr lvl19_rgYs lvl20_rgYt lvl21_rgYu lvl22_rgYv lvl23_rgYw lvl24_rgYx lvl25_rgYy lvl26_rgYz lvl27_rgYA lvl28_rgYB lvl29_rgYC lvl30_rgYD lvl31_rgYE lvl32_rgYF lvl33_rgYG lvl34_rgYH lvl35_rgYI lvl36_rgYJ lvl37_rgYK lvl38_rgYL lvl39_rgYM lvl40_rgYN lvl41_rgYO lvl42_rgYP lvl43_rgYQ lvl44_rgYR lvl45_rgYS lvl46_rgYT lvl47_rgYU lvl48_rgYV lvl49_rgYW lvl50_rgYX lvl51_rgYY lvl52_rgYZ lvl53_rgZ0 lvl54_rgZ1 lvl55_rgZ2 lvl56_rgZ3 lvl57_rgZ4 lvl58_rgZ5 lvl59_rgZ6 lvl60_rgZ7 lvl61_rgZ8 lvl62_rgZ9 lvl63_rgZa lvl64_rgZb lvl65_rgZc lvl66_rgZd ww1_rgZe ww2_rgZf ww3_rgZg ww4_rgZh pinfo_rgZi pinfo1_rgZj pinfo2_rgZk pinfo3_rgZl lvl67_rgZm lvl68_rgZn lvl69_rgZo $wgo12_rgZp eta_sh1k wild_sh1l v_sh1m sat_sh1n }}} I initially found this bug when I added a `SPECIALIZE` pragma for `fool` in `Main.hs`. However, I need `funfolding-use-threshold1000` and the constraint synonym `UCRTElt` in `Foo.hs` to trigger the bug. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12396> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #13548: the 'impossible' happened during building PureScript for profiling
by GHC 08 Apr '17

08 Apr '17

#13548: the 'impossible' happened during building PureScript for profiling -------------------------------------+------------------------------------- Reporter: hdgarrood | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.2 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Compile-time Unknown/Multiple | crash or panic Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- Repro steps: * `git clone https://github.com/purescript/purescript` * `cd purescript` * `git checkout v0.11.2` * `stack build --profile` The error was: {{{ [ 23 of 145] Compiling Language.PureScript.Constants ( src/Language/PureScript/Constants.hs, .stack- work/dist/x86_64-linux/Cabal-1.24.2.0/build/Language/PureScript/Constants.p_o ) ghc: panic! (the 'impossible' happened) (GHC version 8.0.2 for x86_64-unknown-linux): kindPrimRep.go rep_sfuE Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug -- While building package purescript-0.11.2 using: /home/harry/.stack/setup-exe-cache/x86_64-linux/Cabal- simple_mPHDZzAJ_1.24.2.0_ghc-8.0.2 --builddir=.stack- work/dist/x86_64-linux/Cabal-1.24.2.0 build lib:purescript exe:purs --ghc- options " -ddump-hi -ddump-to-file" Process exited with code: ExitFailure 1 }}} Sorry that this is pretty much the complete opposite of a minimal reproducing example, but I have no clue how to go about isolating the part that's actually causing the problem. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13548> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #13544: ghc panic
by GHC 08 Apr '17

08 Apr '17

#13544: ghc panic -------------------------------------+------------------------------------- Reporter: shauryab98 | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.2 Keywords: | Operating System: Windows Architecture: x86_64 | Type of failure: Compile-time (amd64) | crash or panic Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- I got this error: {{{ ghc: panic! (the 'impossible' happened) (GHC version 8.0.2 for x86_64-unknown-mingw32): initTc: unsolved constraints WC {wc_insol = [W] %_a1El :: t_a1Ek[tau:1] (CHoleCan: %)} }}} while compiling the following code {{{#!hs halveEvens :: [Integer] -> [Integer] halveEvens = map . filter (\c -> c%2 == 0) }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13544> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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