December 2015 - ghc-tickets

Re: [GHC] #1290: ghc runs preprocessor too much
by GHC 18 Dec '15

18 Dec '15

#1290: ghc runs preprocessor too much -------------------------------------+------------------------------------- Reporter: guest | Owner: Type: bug | Status: new Priority: normal | Milestone: 8.0.1 Component: Driver | Version: 6.7 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by ezyang): This is related to #618, as if `ghc --make` remembered dependency information it would not need to preprocess *stable* modules. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/1290#comment:9> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #618: Dependency caching in ghc --make
by GHC 18 Dec '15

18 Dec '15

#618: Dependency caching in ghc --make -------------------------------------+------------------------------------- Reporter: simonmar | Owner: Type: task | Status: new Priority: normal | Milestone: ⊥ Component: Compiler | Version: None Resolution: None | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: N/A Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by ezyang): * cc: ezyang (added) Comment: `ghc-shake` is a compiler plugin which is comparable to `ghc --make`, but caches dependencies (through Shake). Here's an implementation that works with 7.10 (with frontend plugins; that patch hasn't been backported to 7.10) https://github.com/ezyang/ghc-shake -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/618#comment:8> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #4340: Add alignment to hsc2hs template
by GHC 18 Dec '15

18 Dec '15

#4340: Add alignment to hsc2hs template -------------------------------------+------------------------------------- Reporter: mitar | Owner: RyanGlScott Type: feature request | Status: new Priority: low | Milestone: 8.0.1 Component: Compiler (FFI) | Version: 6.12.3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #10272 | Differential Rev(s): Phab:D1436 Wiki Page: | -------------------------------------+------------------------------------- Comment (by Ben Gamari <ben@…>): In [changeset:"543127388e8c82bce53b09e904a7ed8562badd22/ghc" 54312738/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="543127388e8c82bce53b09e904a7ed8562badd22" Bump hsc2hs submodule Fixes #4340 }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/4340#comment:8> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9394: Show data/type family instances with ghci's :info command
by GHC 18 Dec '15

18 Dec '15

#9394: Show data/type family instances with ghci's :info command -------------------------------------+------------------------------------- Reporter: s9gf4ult | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: GHCi | Version: 7.6.3 Keywords: ghci | Operating System: Architecture: Unknown/Multiple | Unknown/Multiple Difficulty: Unknown | Type of failure: Blocked By: | None/Unknown Related Tickets: | Test Case: | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- Current version of ghci (7.6.3) does not show data instances. For example, I have some Yesod application and I want to see all data constructors of (Route App) data family instance: {{{#!hs *Application> :info Route App class Eq (Route a) => yesod-routes-1.2.0.6:Yesod.Routes.Class.RenderRoute a where data family Route a1 ... -- Defined in `yesod-routes-1.2.0.6:Yesod.Routes.Class' instance Eq (Route App) -- Defined at Foundation.hs:48:1 instance Read (Route App) -- Defined at Foundation.hs:48:1 ................. }}} It just shows info about `Route`, then info about `App` separately. When I try this: {{{#!hs *Application> :info (Route App) <interactive>:1:2: parse error on input `Route' }}} I am getting parse error. I offer to use this syntax (with parentheses) to show info about instance of data/type family, namely, data constructors and such stuff, just like for ordinal `data`. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9394> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11250: GHC shows core with error
by GHC 18 Dec '15

18 Dec '15

#11250: GHC shows core with error -------------------------------------+------------------------------------- Reporter: crockeea | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.2 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Incorrect Unknown/Multiple | warning at compile-time Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- The following code intentionally does not compile: {{{ {-# LANGUAGE DataKinds, KindSignatures, PolyKinds #-} data Proxy (p :: k) = Proxy data Tagged (t :: k) s = Tagged s proxy :: Tagged t s -> Proxy t -> s proxy = undefined bar :: Tagged (gad :: *) Int bar = undefined foo :: Int foo = proxy bar (Proxy::Proxy 'True) }}} but it produces the following output with GHC and GHCi: {{{ [1 of 1] Compiling Main ( Bug.hs, interpreted ) RAE1 [W] cobox_aLM :: t0_aK4[tau:1] ~ 'True (CNonCanonical) t0_aK4[tau:1] 'True False Bug.hs:13:18: Couldn't match kind ‘Bool’ with ‘*’ Expected type: Proxy t0 Actual type: Proxy 'True In the second argument of ‘proxy’, namely ‘(Proxy :: Proxy True)’ In the expression: proxy bar (Proxy :: Proxy True) In an equation for ‘foo’: foo = proxy bar (Proxy :: Proxy True) Failed, modules loaded: none. }}} This ticket is about the first block printed out. It seems to be a random section of core, and is completely useless to debugging the problem. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11250> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #4092: Floating point manipulation : ulp and coerce IEEE-754 Double# into Word64#
by GHC 18 Dec '15

18 Dec '15

#4092: Floating point manipulation : ulp and coerce IEEE-754 Double# into Word64# -------------------------------------+------------------------------------- Reporter: malosh | Owner: Type: feature request | Status: new Priority: normal | Milestone: 8.0.1 Component: Compiler | Version: 6.12.2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by bgamari): * owner: bgamari => * cc: osa1 (added) Comment: osa1, I believe this is relevant to your recent work on unboxed sums. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/4092#comment:25> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11097: `unlit` executable installed in wrong folder
by GHC 17 Dec '15

17 Dec '15

#11097: `unlit` executable installed in wrong folder -------------------------------------+------------------------------------- Reporter: hvr | Owner: Type: bug | Status: new Priority: normal | Milestone: 8.0.1 Component: Build System | Version: 7.10.2 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- For some reason I don't know, `unlit` is installed into `$topdir` (c.f. `-B$topdir`) rather than `$exedir` (== `$topdir/bin`) IMO, it belongs into `$topdir/bin` instead, where all other internal executables are installed into -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11097> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #1544: Derived Read instances for recursive datatypes with infix constructors are too inefficient
by GHC 17 Dec '15

17 Dec '15

#1544: Derived Read instances for recursive datatypes with infix constructors are too inefficient -------------------------------------+------------------------------------- Reporter: jcpetruzza@… | Owner: Type: bug | Status: new Priority: normal | Milestone: 8.0.1 Component: Compiler | Version: 6.6.1 Resolution: | Keywords: deriving-perf Operating System: Unknown/Multiple | Architecture: Type of failure: Runtime | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by ezyang): * keywords: => deriving-perf -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/1544#comment:34> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #5642: Deriving Generic of a big type takes a long time and lots of space
by GHC 17 Dec '15

17 Dec '15

#5642: Deriving Generic of a big type takes a long time and lots of space -------------------------------------+------------------------------------- Reporter: basvandijk | Owner: bgamari Type: bug | Status: new Priority: normal | Milestone: 8.0.1 Component: Compiler | Version: 7.3 Resolution: | Keywords: deriving-perf Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple performance bug | Test Case: T5642 Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by ezyang): * keywords: => deriving-perf -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/5642#comment:27> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11230: No run-time exception for deferred type errors when error is in a phantom role position
by GHC 17 Dec '15

17 Dec '15

#11230: No run-time exception for deferred type errors when error is in a phantom role position -------------------------------------+------------------------------------- Reporter: darchon | Owner: Type: bug | Status: new Priority: normal | Milestone: 8.0.1 Component: Compiler | Version: 7.11 Keywords: deferred, | Operating System: Unknown/Multiple roles | Architecture: | Type of failure: Incorrect result Unknown/Multiple | at runtime Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- The following code: {{{#!hs {-# LANGUAGE RoleAnnotations #-} {-# OPTIONS_GHC -fdefer-type-errors #-} import Control.Exception newtype Representational a = Representational () type role Representational representational newtype Phantom a = Phantom () type role Phantom phantom testRepresentational :: Representational Char -> Representational Bool testRepresentational = id {-# NOINLINE testRepresentational #-} testPhantom :: Phantom Char -> Phantom Bool testPhantom = id {-# NOINLINE testPhantom #-} throwsException :: String -> a -> IO () throwsException c v = do result <- try (evaluate v) case result of Right _ -> error (c ++ " (Failure): No exception!") -- #if MIN_VERSION_base(4,9,0) Left (TypeError msg) -> putStrLn (c ++ "(Succes): exception found") -- #else -- Left (ErrorCall _) -> putStrLn "Succes: exception found" -- #endif main = do throwsException "representational" testRepresentational throwsException "phantom" testPhantom }}} Produces the following result in HEAD: {{{ representational(Succes): exception found *** Exception: phantom (Failure): No exception! CallStack (from ImplicitParams): error, called at Main.hs:24:16 in main:Main }}} In 7.10.2 (after commenting the `TypeError` line, and uncommenting the `ErrorCall` line), we get the following output: {{{ Succes: exception found Succes: exception found }}} I think the HEAD result is wrong: deferred type errors should always result in a run-time exception when their associated value is evaluated, regardless of whether the error occurred in a phantom role position or not. Looking at the core (`ghc -O0 -ddump-simpl`) in HEAD is see: {{{ -- RHS size: {terms: 3, types: 15, coercions: 0} testRepresentational_rqP :: Representational Char -> Representational Bool [GblId, Str=DmdType b] testRepresentational_rqP = case typeError @ 'Unlifted @ (Char ~# Bool) "Main.hs:13:24: error:\n\ \ \\226\\128\\162 Couldn't match type \\226\\128\\152Char\\226\\128\\153 with \\226\\128\\152Bool\\226\\128\\153\n\ \ Expected type: Representational Char -> Representational Bool\n\ \ Actual type: Representational Bool -> Representational Bool\n\ \ \\226\\128\\162 In the expression: id\n\ \ In an equation for \\226\\128\\152testRepresentational\\226\\128\\153:\n\ \ testRepresentational = id\n\ \(deferred type error)"# of wild0_00 { } -- RHS size: {terms: 1, types: 2, coercions: 10} testPhantom_rqQ :: Phantom Char -> Phantom Bool [GblId, Str=DmdType] testPhantom_rqQ = (id @ (Phantom Bool)) `cast` ((Phantom <Bool, Char>_P{<*>_N})_R -> <Phantom Bool>_R :: (Phantom Bool -> Phantom Bool) ~R# (Phantom Char -> Phantom Bool)) }}} while in 7.10.2 I see: {{{ testRepresentational_rnc :: Representational Char -> Representational Bool [GblId, Str=DmdType b] testRepresentational_rnc = case Control.Exception.Base.runtimeError @ (Char ~ Bool) "Main.hs:13:24:\n\ \ Couldn't match type \\226\\128\\152Char\\226\\128\\153 with \\226\\128\\152Bool\\226\\128\\153\n\ \ Expected type: Representational Char -> Representational Bool\n\ \ Actual type: Representational Bool -> Representational Bool\n\ \ In the expression: id\n\ \ In an equation for \\226\\128\\152testRepresentational\\226\\128\\153:\n\ \ testRepresentational = id\n\ \(deferred type error)"# of wild_00 { } testPhantom_rnd :: Phantom Char -> Phantom Bool [GblId, Str=DmdType b] testPhantom_rnd = case Control.Exception.Base.runtimeError @ (Char ~ Bool) "Main.hs:17:15:\n\ \ Couldn't match type \\226\\128\\152Char\\226\\128\\153 with \\226\\128\\152Bool\\226\\128\\153\n\ \ Expected type: Phantom Char -> Phantom Bool\n\ \ Actual type: Phantom Bool -> Phantom Bool\n\ \ In the expression: id\n\ \ In an equation for \\226\\128\\152testPhantom\\226\\128\\153: testPhantom = id\n\ \(deferred type error)"# of wild_00 { } }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11230> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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