November 2013 - ghc-tickets

Re: [GHC] #8037: GHC panic when compiling unsafeCoerce
by GHC 08 Nov '13

08 Nov '13

#8037: GHC panic when compiling unsafeCoerce ---------------------------------+------------------------------------ Reporter: ghc@… | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.6.1 Resolution: | Keywords: Operating System: MacOS X | Architecture: Unknown/Multiple Type of failure: None/Unknown | Difficulty: Unknown Test Case: | Blocked By: Blocking: | Related Tickets: ---------------------------------+------------------------------------ Comment (by Simon Peyton Jones <simonpj@…>): In [changeset:"a1b6932419a2d425b2a3b7672926a0f9c368f234/ghc"]: {{{ #!CommitTicketReference repository="ghc" revision="a1b6932419a2d425b2a3b7672926a0f9c368f234" Make worker/wrapper robust to bogus unsafeCorece Fixes Trac #8037 }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8037#comment:9> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #4268: Warning for ANN pragmas when GHCi is not supported
by GHC 08 Nov '13

08 Nov '13

#4268: Warning for ANN pragmas when GHCi is not supported -------------------------------+------------------------------------------- Reporter: simonmar | Owner: Type: bug | Status: new Priority: high | Milestone: 7.8.1 Component: Compiler | Version: 7.0.4 Resolution: | Keywords: Operating System: | Architecture: Unknown/Multiple Unknown/Multiple | Difficulty: Easy (less than 1 hour) Type of failure: Other | Blocked By: Test Case: | Related Tickets: #8312, #5105 Blocking: | -------------------------------+------------------------------------------- Changes (by simonmar): * related: 8312, 5105 => #8312, #5105 -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/4268#comment:15> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #4268: Warning for ANN pragmas when GHCi is not supported
by GHC 08 Nov '13

08 Nov '13

#4268: Warning for ANN pragmas when GHCi is not supported -------------------------------+------------------------------------------- Reporter: simonmar | Owner: Type: bug | Status: new Priority: high | Milestone: 7.8.1 Component: Compiler | Version: 7.0.4 Resolution: | Keywords: Operating System: | Architecture: Unknown/Multiple Unknown/Multiple | Difficulty: Easy (less than 1 hour) Type of failure: Other | Blocked By: Test Case: | Related Tickets: 8312, 5105 Blocking: | -------------------------------+------------------------------------------- Changes (by simonmar): * related: => 8312, 5105 -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/4268#comment:14> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #4268: Warning for ANN pragmas when GHCi is not supported
by GHC 08 Nov '13

08 Nov '13

#4268: Warning for ANN pragmas when GHCi is not supported -------------------------------+------------------------------------------- Reporter: simonmar | Owner: Type: bug | Status: new Priority: high | Milestone: 7.8.1 Component: Compiler | Version: 7.0.4 Resolution: | Keywords: Operating System: | Architecture: Unknown/Multiple Unknown/Multiple | Difficulty: Easy (less than 1 hour) Type of failure: Other | Blocked By: Test Case: | Related Tickets: Blocking: | -------------------------------+------------------------------------------- Comment (by simonmar): Thanks for the pointer to #8312, but I don't see where it says that annotations will require a flag, could you help me out? Yes, I think it should be a warning, not an error. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/4268#comment:13> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #4268: Warning for ANN pragmas when GHCi is not supported
by GHC 08 Nov '13

08 Nov '13

#4268: Warning for ANN pragmas when GHCi is not supported -------------------------------+------------------------------------------- Reporter: simonmar | Owner: Type: bug | Status: new Priority: high | Milestone: 7.8.1 Component: Compiler | Version: 7.0.4 Resolution: | Keywords: Operating System: | Architecture: Unknown/Multiple Unknown/Multiple | Difficulty: Easy (less than 1 hour) Type of failure: Other | Blocked By: Test Case: | Related Tickets: Blocking: | -------------------------------+------------------------------------------- Comment (by nomeata): Nevermind, #8312 was not about the `-X` flag; that was just a discussion on the mailing lists. So basically you are saying that we should replace the error message introduced in #8312 by a warning, right? -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/4268#comment:12> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #4268: Warning for ANN pragmas when GHCi is not supported
by GHC 08 Nov '13

08 Nov '13

#4268: Warning for ANN pragmas when GHCi is not supported -------------------------------+------------------------------------------- Reporter: simonmar | Owner: Type: bug | Status: new Priority: high | Milestone: 7.8.1 Component: Compiler | Version: 7.0.4 Resolution: | Keywords: Operating System: | Architecture: Unknown/Multiple Unknown/Multiple | Difficulty: Easy (less than 1 hour) Type of failure: Other | Blocked By: Test Case: | Related Tickets: Blocking: | -------------------------------+------------------------------------------- Comment (by nomeata): According to #8312, Annotations will require a `-X` flag in the future, and in a non-GHCi-compiler, we still get an error (not a warning), requiring distributions to patch annotations out of the code. In light of #8312, do you still think that it should be a warning, and not an error? -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/4268#comment:11> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #4268: Warning for ANN pragmas when GHCi is not supported (was: Annotation extension needs a flag)
by GHC 08 Nov '13

08 Nov '13

#4268: Warning for ANN pragmas when GHCi is not supported -------------------------------+------------------------------------------- Reporter: simonmar | Owner: Type: bug | Status: new Priority: high | Milestone: 7.8.1 Component: Compiler | Version: 7.0.4 Resolution: | Keywords: Operating System: | Architecture: Unknown/Multiple Unknown/Multiple | Difficulty: Easy (less than 1 hour) Type of failure: Other | Blocked By: Test Case: | Related Tickets: Blocking: | -------------------------------+------------------------------------------- Changes (by simonmar): * priority: normal => high * milestone: 7.6.2 => 7.8.1 Comment: We don't want a flag for the ANN pragma, because pragmas don't normally have flags to enable them, they are unconditionally enabled. However, ANN might not be supported if GHC is built without GHCi support (say on a platform that doesn't have GHCi support), so in those cases we want to emit a warning. Therefore this ticket is now for adding a warning when an ANN pragma is being ignored. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/4268#comment:10> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8508: Inlining Unsaturated Function Applications
by GHC 07 Nov '13

07 Nov '13

#8508: Inlining Unsaturated Function Applications ------------------------------+-------------------------------------------- Reporter: crockeea | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.6.2 Keywords: | Operating System: Linux Architecture: x86_64 | Type of failure: Runtime performance bug (amd64) | Test Case: Difficulty: Unknown | Blocking: Blocked By: | Related Tickets: | ------------------------------+-------------------------------------------- After trying a simple test, I noticed some strange performance results from stylistic changes to the code. For example, {{{#!haskell import qualified Data.Vector.Unboxed as U {-# INLINE f #-} f :: U.Vector Int -> U.Vector Int -> U.Vector Int f = U.zipWith (+) -- version 1 --f x = U.zipWith (+) x -- version 2 --f x = (U.zipWith (+) x) . id -- version 3 --f x y = U.zipWith (+) x y -- version 4 main = do let iters = 100 dim = 221184 y = U.replicate dim 0 :: U.Vector Int let ans = iterate (f y) y !! iters putStr $ (show $ U.foldl1' (+) ans) }}} Versions 1 and 2 of `f` run in 1.6 seconds, while versions 3 and 4 run in 0.09 seconds (with vector-0.10.9.1 and GHC 7.6.2, compiling with -O2). According to an answer on the Vector trac (link below), this problem is because GHC only inlines on saturated function applications. Is there any way to expand the cases when GHC inlines to avoid having coding style affect performance? * [https://github.com/haskell/vector/issues/4 Vector Trac] -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8508> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #7200: template-haskell-2.7.0.0 fails to build with GHC 7.0.4 due to missing pragma
by GHC 07 Nov '13

07 Nov '13

#7200: template-haskell-2.7.0.0 fails to build with GHC 7.0.4 due to missing pragma -------------------------------------+------------------------------------ Reporter: tibbe | Owner: duncan Type: bug | Status: new Priority: high | Milestone: 7.8.1 Component: Template Haskell | Version: 7.0.4 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Unknown/Multiple Type of failure: None/Unknown | Difficulty: Unknown Test Case: | Blocked By: Blocking: | Related Tickets: -------------------------------------+------------------------------------ Changes (by hvr): * cc: hvr (added) -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7200#comment:9> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8506: misleading error message for duplicate type class instances
by GHC 07 Nov '13

07 Nov '13

#8506: misleading error message for duplicate type class instances -------------------------------------------+------------------------------- Reporter: carter | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type checker) | Version: 7.6.3 Keywords: | Operating System: Architecture: Unknown/Multiple | Unknown/Multiple Difficulty: Unknown | Type of failure: Blocked By: | None/Unknown Related Tickets: | Test Case: | Blocking: -------------------------------------------+------------------------------- In the following code I accidentally declared a type class more than once, and the error message had absolutely nothing to do with that! {{{ {-# LANGUAGE PolyKinds #-} {-# LANGUAGE BangPatterns #-} {-# LANGUAGE DataKinds #-} {-# LANGUAGE TypeFamilies #-} {-# LANGUAGE GADTs #-} {-# LANGUAGE DeriveDataTypeable #-} {-# LANGUAGE TypeOperators #-} {-# LANGUAGE TemplateHaskell #-} module Numerical.Types.Nat(Nat(..),nat) where import Data.Typeable import Data.Data import Language.Haskell.TH hiding (reify) data Nat = S !Nat | Z deriving (Eq,Show,Read,Typeable,Data) nat :: Int -> TypeQ nat n | n >= 0 = localNat n | otherwise = error "nat: negative" where localNat 0 = conT 'Z localNat n = conT 'S `appT` localNat (n-1) ---------------------- ---------------------- {-# LANGUAGE PolyKinds #-} {-# LANGUAGE BangPatterns #-} {-# LANGUAGE DataKinds #-} {-# LANGUAGE TypeFamilies #-} {-# LANGUAGE GADTs #-} {-# LANGUAGE DeriveDataTypeable #-} {-# LANGUAGE TypeOperators #-} {-# LANGUAGE FlexibleInstances #-} {-# LANGUAGE FlexibleContexts #-} {-# LANGUAGE FunctionalDependencies #-} {-# LANGUAGE UndecidableInstances #-} {-# LANGUAGE ScopedTypeVariables #-} {-# LANGUAGE StandaloneDeriving #-} {-# LANGUAGE CPP #-} {-# LANGUAGE TemplateHaskell #-} {-# LANGUAGE NoImplicitPrelude #-} module Numerical.Types.Shape where import Numerical.Types.Nat import Data.Data type N0 = Z type N1= S N0 type N2 = S N1 type N3 = S N2 type N4 = S N3 type N5 = S N4 type N6 = S N5 type N7 = S N6 type N8 = S N7 type N9 = S N8 type N10 = S N9 class Shapable (n :: Nat) where -- zero rank is boring but lets include it for completeness class Shapable Z where class Shapable One where {- I get the following error src/Numerical/Types/Shape.hs:97:17: Unexpected type `Z' where type variable expected In the declaration of `Shape Z' -} }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8506> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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