November 2013 - ghc-tickets

Re: [GHC] #1885: Improve CPR analysis
by GHC 25 Nov '13

25 Nov '13

#1885: Improve CPR analysis -------------------------------------+------------------------------------ Reporter: simonpj | Owner: simonpj Type: feature request | Status: new Priority: lowest | Milestone: 7.6.2 Component: Compiler | Version: 6.8.1 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 nomeata): * cc: mail@… (added) -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/1885#comment:13> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #5075: CPR optimisation for sum types if only one constructor is used
by GHC 25 Nov '13

25 Nov '13

#5075: CPR optimisation for sum types if only one constructor is used -------------------------------------+------------------------------------ Reporter: batterseapower | Owner: simonpj Type: feature request | Status: new Priority: normal | Milestone: 7.6.2 Component: Compiler | Version: 7.0.3 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 nomeata): * cc: mail@… (added) -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/5075#comment:16> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8509: Doc Formatting - Patch Included
by GHC 24 Nov '13

24 Nov '13

#8509: Doc Formatting - Patch Included -------------------------------------+------------------------------------- Reporter: cschneid | Owner: Type: bug | Status: new Priority: low | Milestone: Component: | Version: 7.6.3 libraries/directory | Operating System: Unknown/Multiple Keywords: | Type of failure: Documentation Architecture: Unknown/Multiple | bug Difficulty: Easy (less than 1 | Test Case: hour) | Blocking: Blocked By: | Related Tickets: | -------------------------------------+------------------------------------- Attached is a patch to fixup a bit of doc formatting in the removeDirectory function. The error cases rendered wrong in a few cases, was just missing a bit of markup. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8509> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #7725: Operators without colons
by GHC 23 Nov '13

23 Nov '13

#7725: Operators without colons ------------------------------------------------+-------------------------- Reporter: monoidal | Owner: Type: bug | Status: closed Priority: normal | Milestone: 7.8.1 Component: Compiler | Version: 7.6.2 Resolution: duplicate | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: GHC accepts invalid program | Unknown/Multiple Test Case: | Difficulty: Blocking: | Unknown | Blocked By: | Related Tickets: ------------------------------------------------+-------------------------- Changes (by monoidal): * status: new => closed * resolution: => duplicate Comment: Closing in favor of #8556. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7725#comment:3> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8503: New GeneralizedNewtypeDeriving check still isn't permissive enough
by GHC 23 Nov '13

23 Nov '13

#8503: New GeneralizedNewtypeDeriving check still isn't permissive enough ------------------------------------+------------------------------------- Reporter: goldfire | Owner: goldfire Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.7 Keywords: | Operating System: Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+------------------------------------- Roman Cheplyaka writes: I just tried compiling smallcheck with GHC HEAD, and it didn't work out: {{{ Test/SmallCheck/SeriesMonad.hs:41:7: Can't make a derived instance of ‛MonadLogic (Series m)’ (even with cunning newtype deriving): it is not type-safe to use GeneralizedNewtypeDeriving on this class; ‛msplit’, at type ‛forall a. m a -> m (Maybe (a, m a))’, cannot be converted safely In the newtype declaration for ‛Series’ }}} So GHC now looks at the methods, but the problem is still there. I would agree that `msplit`'s type is problematic (due to the nested `m`'s), but Simon and Richard previously said that it should work, so I'm confused. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8503> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8553: ASSERT failed compiler/typecheck/TcMType.lhs line 809
by GHC 23 Nov '13

23 Nov '13

#8553: ASSERT failed compiler/typecheck/TcMType.lhs line 809 -------------------------------------+------------------------------------- Reporter: nomeata | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 7.6.3 checker) | Operating System: Unknown/Multiple Keywords: | Type of failure: Compile-time Architecture: Unknown/Multiple | crash Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | -------------------------------------+------------------------------------- With current master (9c2dade94fae5f4fe19cd972ca1f1049c633e4ed) I get {{{ [1 of 1] Compiling ShouldCompile ( ../ghc/gadt6.hs, ../ghc/gadt6.o ) ghc-stage2: panic! (the 'impossible' happened) (GHC version 7.7.20131121 for x86_64-unknown-linux): ASSERT failed! file compiler/typecheck/TcMType.lhs line 809 [W] cobox_aBx{v} [lid] :: t_aBv{tv} [tau[0]] ghc-prim:GHC.Types.~{(w) tc 31Q} t_aBu{tv} [tau[0]] (CIrredEvCan) }}} (And it took me a while to figure out that it was not my code that was introducing the bug.) According to `git log -L 809,809:compiler/typecheck/TcMType.lhs` (a useful feature) the history of the ASSERT is: * SPJ, “Accommodate Derived constraints in two places”, Sep 17, 8cfbdccb7f8716c2b6b13b3c7884f52b1087d782 * SPJ, “Fix an ASSERT”, Oct 1 2012, adb6bcb7b85410dd42828a4824962ce9c6e9d667 * SPJ, “Tidy up and simplify TcMType.zonkFlats”, Sep 17, 2012, bd6b183e092fc7667fc55b3aa15d857f257ec73f -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8553> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8537: confusing error message for specialize pragma
by GHC 22 Nov '13

22 Nov '13

#8537: confusing error message for specialize pragma ------------------------------------+------------------------------------- Reporter: carter | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.6.3 Keywords: | Operating System: Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+------------------------------------- I get the following confusing error/warning about SPECIALIZE {{{ SPECIALISE pragma for non-overloaded function `$cfmap' }}} with the following example module {{{ {-# LANGUAGE PolyKinds #-} {-# LANGUAGE BangPatterns #-} {-# LANGUAGE DataKinds #-} {-# LANGUAGE TypeFamilies #-} {-# LANGUAGE GADTs #-} {-# LANGUAGE DeriveDataTypeable #-} {-# LANGUAGE TypeOperators #-} {-# LANGUAGE FlexibleInstances #-} {-# LANGUAGE FlexibleContexts #-} {-# LANGUAGE FunctionalDependencies #-} {-# LANGUAGE UndecidableInstances #-} {-# LANGUAGE ScopedTypeVariables #-} {-# LANGUAGE StandaloneDeriving #-} {-# LANGUAGE CPP #-} {-# LANGUAGE TemplateHaskell #-} {-# LANGUAGE NoImplicitPrelude #-} module Numerical.Types.Shape where import Control.Applicative import Data.Foldable import Data.Monoid import Data.Functor import Prelude (seq, ($!),($),Show(..),Eq(),Int) data Nat = S !Nat | Z --deriving (Eq,Show,Read) {- not doing the HLIST style shape because I don't want to have any pattern matchings going on. Also would play hell with locality quality in the address translation hackery, because there'd be an extra load to get those ints! -} infixr 3 :* {- the concern basically boils down to "will it specialize / inline well" -} data Shape (rank :: Nat) a where Nil :: Shape Z a (:*) :: !(a) -> !(Shape r a ) -> Shape (S r) a --deriving instance (Show (Shape rank a)) -- deriving instance Eq (Shape rank a) -- #if defined( __GLASGOW_HASKELL__ ) && ( __GLASGOW_HASKELL__ >= 707) --deriving instance Typeable (Shape rank a) -- #endif instance Functor (Shape Z) where fmap = \ f Nil -> Nil {-# INLINABLE fmap #-} {-# SPECIALIZE fmap :: (Int ->Int )-> (Shape Z Int)-> (Shape Z Int) #-} }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8537> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #2850: GeneralizedNewtypeDeriving + TypeFamilies doesn't work
by GHC 22 Nov '13

22 Nov '13

#2850: GeneralizedNewtypeDeriving + TypeFamilies doesn't work -------------------------------------------------+------------------------- Reporter: ajd | Owner: Type: feature request | Status: Priority: normal | closed Component: Compiler | Milestone: 6.12 Resolution: fixed | branch Operating System: Unknown/Multiple | Version: Type of failure: None/Unknown | 6.10.1 Test Case: | Keywords: indexed_types/should_compile/T2850 | Architecture: Blocking: | Unknown/Multiple | Difficulty: | Unknown | Blocked By: | Related Tickets: -------------------------------------------------+------------------------- Comment (by goldfire): As far as I can tell, my comment above (comment 10) is pure gibberish. There was a thought in my head somewhere, but every time I feel like I'm getting close to it, it runs away. Besides, after a little while trying, I was unable to come up with a relevant example. If there really is an issue here, we'll wait for someone to really hit it and yell. Otherwise, I'll move on. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/2850#comment:12> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8450: can't match type Bool with (), but shouldn't have to
by GHC 22 Nov '13

22 Nov '13

#8450: can't match type Bool with (), but shouldn't have to ------------------------------------+------------------------------------- Reporter: dmwit | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.6.3 Keywords: | Operating System: Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+------------------------------------- The following (definitely type-incorrect) file: {{{ {-# LANGUAGE ScopedTypeVariables #-} runEffect :: Either Bool r -> r runEffect = undefined run :: forall a. a run = runEffect $ (undefined :: Either a ()) }}} produces the following error: {{{ test.hs:7:7: Couldn't match type `Bool' with `()' Expected type: a Actual type: () In the expression: runEffect $ (undefined :: Either a ()) In an equation for `run': run = runEffect $ (undefined :: Either a ()) }}} This is strange because one of the two types it claims it can't unify (Bool) doesn't appear in either the expected or actual type. Note that removing the ($) gets a different error message that makes it a bit more clear what's going on: {{{ test.hs:7:18: Couldn't match type `Bool' with `()' Expected type: Either Bool a Actual type: Either a () In the first argument of `runEffect', namely `(undefined :: Either a ())' In the expression: runEffect (undefined :: Either a ()) In an equation for `run': run = runEffect (undefined :: Either a ()) }}} So it seems it's trying to unify Bool and () because it's unifying both a with Bool and a with (); however, the usual comments about rigid type variables aren't there, which makes even this error message a bit confusing. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8450> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8526: -fforce-recomp does not re-summarise modules
by GHC 22 Nov '13

22 Nov '13

#8526: -fforce-recomp does not re-summarise modules ------------------------------------+------------------------------------- Reporter: parcs | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Driver | Version: 7.6.3 Keywords: | Operating System: Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+------------------------------------- -fforce-recomp should re-summarise modules so that the source file will get re-preprocessed. Otherwise a modification to an `#include`'d file will not get picked up. {{{ $ ghci -XCPP -v0 -fforce-recomp Prelude> :! echo '#include "A.hs-inc"' > A.hs Prelude> :! echo 'a = True' > A.hs-inc Prelude> :l A *Main> a True *Main> :! echo 'a = False' > A.hs-inc *Main> :r *Main> a True *Main> }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8526> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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