April 2014 - ghc-tickets

Re: [GHC] #7898: SpecConstr explodes when compiling module BSP of frag-1.1.2
by GHC 09 Apr '14

09 Apr '14

#7898: SpecConstr explodes when compiling module BSP of frag-1.1.2 ---------------------------------------+----------------------------------- Reporter: tinctorius | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.6.3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time crash | Unknown/Multiple Test Case: | Difficulty: Unknown Blocking: | Blocked By: | Related Tickets: ---------------------------------------+----------------------------------- Changes (by slyfox): * cc: slyfox@… (added) -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7898#comment:13> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #5435: GHCi linker should run constructors for linked libraries
by GHC 09 Apr '14

09 Apr '14

#5435: GHCi linker should run constructors for linked libraries -------------------------------------+------------------------------------ Reporter: pumpkin | Owner: Type: bug | Status: closed Priority: normal | Milestone: 7.8.1 Component: Compiler | Version: 7.2.1 Resolution: fixed | Keywords: Operating System: Unknown/Multiple | Architecture: Unknown/Multiple Type of failure: None/Unknown | Difficulty: Unknown Test Case: | Blocked By: Blocking: 7746, 8199 | Related Tickets: #3658 -------------------------------------+------------------------------------ Comment (by Edward Z. Yang <ezyang@…>): In [changeset:"f8e12e2b396e0c475e1403ab8ac3fc4d63c1681e/ghc"]: {{{ #!CommitTicketReference repository="ghc" revision="f8e12e2b396e0c475e1403ab8ac3fc4d63c1681e" Fix #5435, adding new test config check_stdout. check_stdout(f) allows you to override the test framework's diff based output checking with another mechanism. f is a function which takes two arguments: the first is the filename containing the observed stdout, the second is the normaliser that would have been applied (in case you want to read, normalise, and then do something.) Signed-off-by: Edward Z. Yang <ezyang(a)cs.stanford.edu> }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/5435#comment:41> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #7883: enable GHC LLVM backend to use LLVM provided CAS / Atomicity primitives?
by GHC 08 Apr '14

08 Apr '14

#7883: enable GHC LLVM backend to use LLVM provided CAS / Atomicity primitives? -------------------------------------+------------------------------------ Reporter: carter | Owner: carter Type: task | Status: new Priority: normal | Milestone: 7.10.1 Component: Compiler | Version: 7.9 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 carter): * version: 7.7 => 7.9 * milestone: => 7.10.1 -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7883#comment:16> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #7068: Extensive Memory usage (regression)
by GHC 08 Apr '14

08 Apr '14

#7068: Extensive Memory usage (regression) -------------------------------------------------+------------------------- Reporter: waldheinz | Owner: Type: bug | simonpj Priority: high | Status: new Component: Compiler | Milestone: 7.8.1 Resolution: | Version: 7.4.1 Operating System: Unknown/Multiple | Keywords: Type of failure: Compile-time performance bug | Architecture: Test Case: | Unknown/Multiple Blocking: | Difficulty: | Unknown | Blocked By: | Related Tickets: -------------------------------------------------+------------------------- Comment (by nh2): pcapriotti's Vec example doesn't seem to blow up for me on 7.6.3 Linux. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7068#comment:9> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8961: Require PatternSynonyms language extension to *use* pattern synonyms
by GHC 08 Apr '14

08 Apr '14

#8961: Require PatternSynonyms language extension to *use* pattern synonyms -------------------------------------------+------------------------------- Reporter: cactus | Owner: cactus Type: bug | Status: new Priority: normal | Milestone: 7.8.1 Component: Compiler (Type checker) | Version: 7.8.1-rc2 Keywords: | Operating System: Architecture: Unknown/Multiple | Unknown/Multiple Difficulty: Easy (less than 1 hour) | Type of failure: Blocked By: | None/Unknown Related Tickets: | Test Case: | Blocking: -------------------------------------------+------------------------------- To keep in the spirit of #2905, especially in light of the immaturity of the pattern synonyms extensions, GHC should require the `PatternSynonyms` language extension to be turned on when encountering a pattern synonym occurance. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8961> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8969: GHCi crash on invalid input
by GHC 07 Apr '14

07 Apr '14

#8969: GHCi crash on invalid input ------------------------------------+------------------------------------- Reporter: aslpavel | 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: GHCi crash Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+------------------------------------- I know its incorrect haskell code but after entering following sequence of commands, ghci seems to be crashing. {{{ GHCi, version 7.6.3: http://www.haskell.org/ghc/ :? for help Loading package ghc-prim ... linking ... done. Loading package integer-gmp ... linking ... done. Loading package base ... linking ... done. λ > data R = R { x1 :: Int, x2 :: Int, x3 :: Int } deriving Show λ > data R a = State { x1 :: Int, x2 :: Int, x3 :: Int } a ghc: panic! (the 'impossible' happened) (GHC version 7.6.3 for x86_64-unknown-linux): tc_hs_type: record Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} I hope it would be helpful. Thanks! -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8969> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8950: Typeable instances for promoted lists and tuples
by GHC 07 Apr '14

07 Apr '14

#8950: Typeable instances for promoted lists and tuples ------------------------------------+------------------------------------- Reporter: kosmikus | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: libraries/base | Version: 7.8.1-rc2 Keywords: | Operating System: Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+------------------------------------- Please have a look at the following sample module: {{{ {-# LANGUAGE DataKinds, KindSignatures, PolyKinds, AutoDeriveTypeable #-} {-# LANGUAGE StandaloneDeriving, DeriveDataTypeable #-} import Data.Proxy import Data.Typeable data Foo (xs :: [*]) (p :: (*, *)) main :: IO () main = print (typeRep (Proxy :: Proxy (Foo '[Int] '(Bool, Char)))) -- Code above checks only with these instances, but shouldn't they -- be predefined? -- -- deriving instance Typeable '[] -- deriving instance Typeable '(:) -- deriving instance Typeable '(,) }}} The good news is that the code does in principle work, but as the comments say, I would have expected this to work without having to define additional instances. (A somewhat related question is whether concrete type literals such as `3 :: Nat` or `"foo" :: Symbol` should be instances of `Typeable`. They don't seem to be, and `deriving` does not work in these cases.) -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8950> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8952: Bang patterns don't work as the specification says
by GHC 07 Apr '14

07 Apr '14

#8952: Bang patterns don't work as the specification says --------------------------+------------------------------------------------ Reporter: dolio | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: | Version: 7.6.3 Compiler | Operating System: Unknown/Multiple Keywords: | Type of failure: Incorrect result at runtime Architecture: | Test Case: Unknown/Multiple | Blocking: Difficulty: | Unknown | Blocked By: | Related Tickets: | --------------------------+------------------------------------------------ In investigating the behavior of bang patterns for an implementation of my own, I came across a discrepancy between the specification and GHC's implementation. Here is an example: {{{ case Nothing of !(~(Just x)) -> 5 Nothing -> 12 }}} This evaluates to 12. In other words, !(~p) is equivalent to p. However, the bang patterns description says that this should be equivalent to: {{{ Nothing `seq` case Nothing of ~(Just x) -> 5 Nothing -> 12 }}} which evaluates to 5. So, one of either the description or the implementation must be incorrect. In fact, GHC is even a bit confused, as it issues a warning about overlapping patterns for the bang pattern case statement, even though the successful branch is the 'unreachable' one. The description makes more sense to me, but I'm not terribly invested in the behavior of this; it is admittedly a pretty obscure corner case. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8952> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8937: Wrong jump target in stg_maskUninterruptiblezh
by GHC 07 Apr '14

07 Apr '14

#8937: Wrong jump target in stg_maskUninterruptiblezh ------------------------------------+------------------------------------- Reporter: hsjunn | Owner: simonmar Type: bug | Status: new Priority: normal | Milestone: Component: Runtime System | 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 stack check there reads: STK_CHK_P_LL (WDS(1)/* worst case */, stg_maskAsyncExceptionszh, R1); Isn't that supposed to be STK_CHK_P_LL (WDS(1)/* worst case */, stg_maskUninterruptiblezh, R1); ? -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8937> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8931: The type defaulting in GHCi with Typeable
by GHC 07 Apr '14

07 Apr '14

#8931: The type defaulting in GHCi with Typeable -------------------------------------+------------------------------------- Reporter: skata | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 7.8.1-rc2 checker) | Operating System: Unknown/Multiple Keywords: type defaulting, | Type of failure: GHC rejects Typeable | valid program Architecture: Unknown/Multiple | Test Case: Difficulty: Unknown | Blocking: Blocked By: | Related Tickets: | -------------------------------------+------------------------------------- The type defaulting in GHCi works in less cases with GHC 7.8.1-rc2 than with older versions, though there is no change in the related part of the documentation (i.e., "2.4.7 Type defaulting in GHCi"). {{{ skata@kata58:~$ ghc --version The Glorious Glasgow Haskell Compilation System, version 7.8.0.20140228 skata@kata58:~$ ghci GHCi, version 7.8.0.20140228: http://www.haskell.org/ghc/ :? for help Loading package ghc-prim ... linking ... done. Loading package integer-gmp ... linking ... done. Loading package base ... linking ... done. Prelude> :m +Data.Typeable Prelude Data.Typeable> let {f :: Read a => (a->Bool) -> Char; f = undefined} Prelude Data.Typeable> f (\x -> (x == 3)) *** Exception: Prelude.undefined <== This is the expected result. Prelude Data.Typeable> let {f :: Typeable a => (a->Bool) -> Char; f = undefined} Prelude Data.Typeable> f (\x -> (x == 3)) <== Type defaulting does not work in this case. <interactive>:6:1: No instance for (Typeable a0) arising from a use of ‘f’ The type variable ‘a0’ is ambiguous Note: there are several potential instances: instance [overlap ok] Typeable () -- Defined in ‘Data.Typeable.Internal’ instance [overlap ok] Typeable Bool -- Defined in ‘Data.Typeable.Internal’ instance [overlap ok] Typeable Char -- Defined in ‘Data.Typeable.Internal’ ...plus 14 others In the expression: f (\ x -> (x == 3)) In an equation for ‘it’: it = f (\ x -> (x == 3)) <interactive>:6:13: No instance for (Eq a0) arising from a use of ‘==’ The type variable ‘a0’ is ambiguous Relevant bindings include x :: a0 (bound at <interactive>:6:5) Note: there are several potential instances: instance Eq a => Eq (GHC.Real.Ratio a) -- Defined in ‘GHC.Real’ instance Eq Integer -- Defined in ‘integer-gmp:GHC.Integer.Type’ instance Eq () -- Defined in ‘GHC.Classes’ ...plus 33 others In the expression: (x == 3) In the first argument of ‘f’, namely ‘(\ x -> (x == 3))’ In the expression: f (\ x -> (x == 3)) <interactive>:6:16: No instance for (Num a0) arising from the literal ‘3’ The type variable ‘a0’ is ambiguous Relevant bindings include x :: a0 (bound at <interactive>:6:5) Note: there are several potential instances: instance Num Double -- Defined in ‘GHC.Float’ instance Num Float -- Defined in ‘GHC.Float’ instance Integral a => Num (GHC.Real.Ratio a) -- Defined in ‘GHC.Real’ ...plus 7 others In the second argument of ‘(==)’, namely ‘3’ In the expression: (x == 3) In the first argument of ‘f’, namely ‘(\ x -> (x == 3))’ }}} On the other hand, {{{ skata@kata58:~$ ghc --version The Glorious Glasgow Haskell Compilation System, version 7.4.1 skata@kata58:~$ ghci GHCi, version 7.4.1: http://www.haskell.org/ghc/ :? for help Loading package ghc-prim ... linking ... done. Loading package integer-gmp ... linking ... done. Loading package base ... linking ... done. Prelude> :m +Data.Typeable Prelude Data.Typeable> let {f :: Read a => (a->Bool) -> Char; f = undefined} Prelude Data.Typeable> f (\x -> (x == 3)) *** Exception: Prelude.undefined Prelude Data.Typeable> let {f :: Typeable a => (a->Bool) -> Char; f = undefined} Prelude Data.Typeable> f (\x -> (x == 3)) *** Exception: Prelude.undefined }}} I think the old behavior is compliant with the documentation. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8931> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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