June 2014 - ghc-tickets

Re: [GHC] #229: Integer overflow in array allocation
by GHC 05 Jun '14

05 Jun '14

#229: Integer overflow in array allocation --------------------------------------+------------------------------------ Reporter: josefs | Owner: rwbarton Type: bug | Status: new Priority: normal | Milestone: ⊥ Component: libraries (other) | Version: 7.8.1 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 rwbarton): * owner: => rwbarton * priority: low => normal * version: 6.4.1 => 7.8.1 * component: libraries/base => libraries (other) Comment: This bug still exists. With a little more care you can read and write arbitrary memory. {{{ import Data.Array.MArray import Data.Array.IO import Data.Word main = do m <- newArray_ (0,2^62-1) :: IO (IOUArray Int Word32) -- allocates 0 bytes writeArray m 17 12345 -- write wherever you like }}} The `unsafeNewArray_` definitions in `Data.Array.Base` need to check for integer overflow when computing the size in bytes to be allocated. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/229#comment:15> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #7828: RebindableSyntax and Arrow
by GHC 05 Jun '14

05 Jun '14

#7828: RebindableSyntax and Arrow ----------------------------------------------+---------------------------- Reporter: AlessandroVermeulen | Owner: Type: bug | jstolarek Priority: normal | Status: new Component: Compiler (Type checker) | Milestone: 7.10.1 Resolution: | Version: 7.6.2 Operating System: Unknown/Multiple | Keywords: Type of failure: GHC rejects valid program | Architecture: Test Case: | Unknown/Multiple Blocking: | Difficulty: Unknown | Blocked By: | Related Tickets: ----------------------------------------------+---------------------------- Comment (by ross): Replying to [comment:18 simonpj]: > Ross that looks attractive. Is it enough for desugaring? That is, is the translation above what you would use for desugaring? It looks a LOT simpler than the present desugaring! It's only part of it. This would treat do and if commands as derived constructs, defined in terms of a kernel command language. But that language would still need to be type-checked using the command rules (with their split environments), and would still need to be translated into expressions, as now. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7828#comment:19> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #7828: RebindableSyntax and Arrow
by GHC 05 Jun '14

05 Jun '14

#7828: RebindableSyntax and Arrow ----------------------------------------------+---------------------------- Reporter: AlessandroVermeulen | Owner: Type: bug | jstolarek Priority: normal | Status: new Component: Compiler (Type checker) | Milestone: 7.10.1 Resolution: | Version: 7.6.2 Operating System: Unknown/Multiple | Keywords: Type of failure: GHC rejects valid program | Architecture: Test Case: | Unknown/Multiple Blocking: | Difficulty: Unknown | Blocked By: | Related Tickets: ----------------------------------------------+---------------------------- Comment (by simonpj): Ross that looks attractive. Is it enough for desugaring? That is, is the translation above what you would use for desugaring? It looks a LOT simpler than the present desugaring! Simon -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7828#comment:18> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #17: Separate warnings for unused local and top-level bindings
by GHC 05 Jun '14

05 Jun '14

#17: Separate warnings for unused local and top-level bindings -----------------------------------+--------------------------------------- Reporter: magunter | Owner: Type: feature | Status: new request | Milestone: ⊥ Priority: lowest | Version: None Component: Compiler | Keywords: -fwarn-unused-binds Resolution: None | Architecture: Unknown/Multiple Operating System: | Difficulty: Unknown Unknown/Multiple | Blocked By: Type of failure: None/Unknown | Related Tickets: Test Case: | Blocking: | -----------------------------------+--------------------------------------- Comment (by errge): Note that you can simply prefix those "used from GHCi only top-level bindings" with an underscore as a workaround until this gets implemented. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/17#comment:13> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9165: Export TimerManager from GHC.Event
by GHC 04 Jun '14

04 Jun '14

#9165: Export TimerManager from GHC.Event -------------------------------------------+------------------------------- Reporter: basvandijk | Owner: Type: task | Status: new Priority: normal | Milestone: Component: libraries/base | Version: 7.8.2 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: -------------------------------------------+------------------------------- [http://hackage.haskell.org/package/base-4.7.0.0/docs/GHC-Event.html GHC.Event] exports `getSystemTimerManager` but not the actual `TimerManager` type. I propose to export it so that the haddocks are properly linked and users can actually refer to `TimerManager` in their type signatures. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9165> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #7828: RebindableSyntax and Arrow
by GHC 04 Jun '14

04 Jun '14

#7828: RebindableSyntax and Arrow ----------------------------------------------+---------------------------- Reporter: AlessandroVermeulen | Owner: Type: bug | jstolarek Priority: normal | Status: new Component: Compiler (Type checker) | Milestone: 7.10.1 Resolution: | Version: 7.6.2 Operating System: Unknown/Multiple | Keywords: Type of failure: GHC rejects valid program | Architecture: Test Case: | Unknown/Multiple Blocking: | Difficulty: Unknown | Blocked By: | Related Tickets: ----------------------------------------------+---------------------------- Comment (by ross): Here's a different suggestion for rebinding that is perhaps more analogous to the expression case. We could consider do and if commands as sugar for more primitive commands: {{{ do { p <- cmd; stmts } = cmd `bind` \ p -> do { stmts } do { cmd; stmts } = cmd `bind_` do { stmts } do { let defs; stmts } = let defs in do { stmts } do { cmd } = cmd if exp then cmd1 else cmd2 = (| ifThenElseA cmd1 cmd2 |) exp }}} (remember these are commands, not expressions), given the ordinary Haskell definitions {{{ bind :: Arrow a => a (e,s) b -> a (e,(b,s)) c -> a (e,s) c u `bind` f = arr id &&& u >>> arr (\ ((e,s),b) -> (e,(b,s))) >>> f bind_ :: Arrow a => a (e,s) b -> a (e,s) c -> a (e,s) c u `bind_` v = arr id &&& u >>> arr fst >>> v ifThenElseA :: ArrowChoice a => a (e,s) r -> a (e,s) r -> a (e,(Bool,s)) r ifThenElseA thenPart elsePart = arr split >>> thenPart ||| elsePart where split (e, (True, s)) = Left (e, s) split (e, (False, s)) = Right (e, s) }}} Then rebinding would just use whatever definitions of these names are in scope, and they could be associated with {{{BindStmt}}}, etc, in a similar way to expressions. But would this be enough for the people who want rebinding? -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7828#comment:17> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #7828: RebindableSyntax and Arrow
by GHC 04 Jun '14

04 Jun '14

#7828: RebindableSyntax and Arrow ----------------------------------------------+---------------------------- Reporter: AlessandroVermeulen | Owner: Type: bug | jstolarek Priority: normal | Status: new Component: Compiler (Type checker) | Milestone: 7.10.1 Resolution: | Version: 7.6.2 Operating System: Unknown/Multiple | Keywords: Type of failure: GHC rejects valid program | Architecture: Test Case: | Unknown/Multiple Blocking: | Difficulty: Unknown | Blocked By: | Related Tickets: ----------------------------------------------+---------------------------- Comment (by ross): Replying to [comment:15 jstolarek]: > Thanks Ross. I think I still don't understand the stk thing. What are the "anonymous inputs to the arrow"? Is that described in any of the arrow papers? They are command arguments, the arrow analogue of function arguments. But with arrows they have to be tupled up with the local environment as the input to the arrow. In the notation paper (section 3.2) these arguments are attached to the environment with a series of pairings, but before 7.8 I had to change the representation to fit with GHC's constraint-based typechecker. Now the environment and stack are separate tuples, combined in a pair. > > The simplifier reduces that to an identity using rules in Control.Arrow > > How can I observe that? Using `-ddump-simpl` only shows that this huge expression is split into many smaller functions but it doesn't look like anything gets simplified. Using `-ddump-rules` and `-ddump-rule-rewrites` I see that some rules fire but none of them seems to optimize the above expression. I used -O as well (this is with GHC 7.8.2). -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7828#comment:16> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #7730: :info and polykinds
by GHC 04 Jun '14

04 Jun '14

#7730: :info and polykinds --------------------------------------------+------------------------------ Reporter: monoidal | Owner: archblob Type: bug | Status: patch Priority: normal | Milestone: 7.10.1 Component: Compiler (Type checker) | Version: 7.6.2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: None/Unknown | Unknown/Multiple Test Case: | Difficulty: Unknown Blocking: | Blocked By: | Related Tickets: #8776 --------------------------------------------+------------------------------ Comment (by archblob): Oh, thank you. I'm glad that I could help and this is all over. I think the ticked can be marked as fixed now. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7730#comment:54> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #7730: :info and polykinds
by GHC 04 Jun '14

04 Jun '14

#7730: :info and polykinds --------------------------------------------+------------------------------ Reporter: monoidal | Owner: archblob Type: bug | Status: patch Priority: normal | Milestone: 7.10.1 Component: Compiler (Type checker) | Version: 7.6.2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: None/Unknown | Unknown/Multiple Test Case: | Difficulty: Unknown Blocking: | Blocked By: | Related Tickets: #8776 --------------------------------------------+------------------------------ Comment (by Simon Peyton Jones <simonpj@…>): In [changeset:"dd9943472d385b55f9baa56780f333a190794bcf/ghc"]: {{{ #!CommitTicketReference repository="ghc" revision="dd9943472d385b55f9baa56780f333a190794bcf" Comments only (related to Trac #7730) }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7730#comment:53> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #7828: RebindableSyntax and Arrow
by GHC 04 Jun '14

04 Jun '14

#7828: RebindableSyntax and Arrow ----------------------------------------------+---------------------------- Reporter: AlessandroVermeulen | Owner: Type: bug | jstolarek Priority: normal | Status: new Component: Compiler (Type checker) | Milestone: 7.10.1 Resolution: | Version: 7.6.2 Operating System: Unknown/Multiple | Keywords: Type of failure: GHC rejects valid program | Architecture: Test Case: | Unknown/Multiple Blocking: | Difficulty: Unknown | Blocked By: | Related Tickets: ----------------------------------------------+---------------------------- Comment (by jstolarek): Thanks Ross. I think I still don't understand the stk thing. What are the "anonymous inputs to the arrow"? Is that described in any of the arrow papers? > The simplifier reduces that to an identity using rules in Control.Arrow How can I observe that? Using `-ddump-simpl` only shows that this huge expression is split into many smaller functions but it doesn't look like anything gets simplified. Using `-ddump-rules` and `-ddump-rule-rewrites` I see that some rules fire but none of them seems to optimize the above expression. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7828#comment:15> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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