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[GHC] #12956: Something has broken T12903
by GHC 14 Dec '16

14 Dec '16

#12956: Something has broken T12903 --------------------------------------+--------------------------------- Reporter: bgamari | Owner: bgamari Type: bug | Status: new Priority: high | Milestone: 8.2.1 Component: Runtime System | Version: 8.0.1 Keywords: | Operating System: MacOS X Architecture: x86_64 (amd64) | Type of failure: None/Unknown Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: --------------------------------------+--------------------------------- 895a131f6e56847d9ebca2e9bfe19a3189e49d72, which fixes #12903, seems to be broken on OS X. The tree was known to compile at 499e43824bda967546ebf95ee33ec1f84a114a7c and is known to be broken at 61932cd3eb0d5d22cb35d118fb9f87298881cd77. I'll need to figure out which of the intervening commits broken it -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12956> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #12550: Inconsistent unicode display for kinds
by GHC 14 Dec '16

14 Dec '16

#12550: Inconsistent unicode display for kinds --------------------------------------+--------------------------------- Reporter: johnleo | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 Keywords: | Operating System: MacOS X Architecture: x86_64 (amd64) | Type of failure: None/Unknown Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: --------------------------------------+--------------------------------- With `:set -fprint-unicode-syntax`, the kind `*` should always be printed as `★`. However the output is extremely inconsistent. Here are a few examples from ghci, and I will add more as I run across them. {{{ :t fmap fmap ∷ ∀ {f ∷ ★ → ★} {a} {b}. Functor f ⇒ (a → b) → f a → f b :i fmap class Functor (f ∷ * → *) where fmap ∷ forall a b. (a → b) → f a → f b :k Functor Functor ∷ (★ → ★) → Constraint :m + GHC.Generics :i Functor -- (among other output) instance ∀ (f ∷ * → ★). Functor f ⇒ Functor (Rec1 f) -- Defined in ‘GHC.Generics’ instance Functor Par1 -- Defined in ‘GHC.Generics’ instance ∀ i (c ∷ Meta) (f ∷ * → ★). Functor f ⇒ Functor (M1 i c f) -- Defined in ‘GHC.Generics’ instance ∀ i c. Functor (K1 i c) -- Defined in ‘GHC.Generics’ instance ∀ (f ∷ * → ★) (g ∷ * → *). (Functor f, Functor g) ⇒ Functor (f :.: g) -- Defined in ‘GHC.Generics’ instance ∀ (f ∷ * → ★) (g ∷ * → ★). (Functor f, Functor g) ⇒ Functor (f :+: g) -- Defined in ‘GHC.Generics’ instance ∀ (f ∷ * → ★) (g ∷ * → ★). (Functor f, Functor g) ⇒ Functor (f :*: g) -- Defined in ‘GHC.Generics’ :t datatypeName datatypeName ∷ ∀ {d} {t ∷ ★ → (* → *) → ★ → ★} {f ∷ * → *} {a}. Datatype ★ d ⇒ t d f a → [Char] :i datatypeName class Datatype k (d ∷ k) where datatypeName ∷ forall {k1} (t ∷ k → (* → *) → k1 → *) (f ∷ * → *) (a ∷ k1). t d f a → [Char] ... -- Defined in ‘GHC.Generics’ }}} Note that `:t datatypeName` causes a panic in 8.1; I have filed a separate bug [https://ghc.haskell.org/trac/ghc/ticket/12549] -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12550> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #12880: Update to Cabal-1.24.1.1
by GHC 14 Dec '16

14 Dec '16

#12880: Update to Cabal-1.24.1.1 -------------------------------------+------------------------------------- Reporter: hvr | Owner: Type: task | Status: new Priority: high | Milestone: 8.0.2 Component: libraries | Version: 8.0.2-rc1 (other) | 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: -------------------------------------+------------------------------------- This is a tracking ticket to make sure it we don't forget about this. See https://github.com/haskell/cabal/issues/4123 -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12880> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #12894: Bump directory
by GHC 14 Dec '16

14 Dec '16

#12894: Bump directory -------------------------------------+------------------------------------- Reporter: bgamari | Owner: Type: bug | Status: new Priority: high | Milestone: 8.0.2 Component: Compiler | Version: 8.0.1 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: -------------------------------------+------------------------------------- dcoutts says that `canonicalizePath` in the version shipped with 8.0.1 is buggy. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12894> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #4505: Segmentation fault on long input (list of pairs)
by GHC 14 Dec '16

14 Dec '16

#4505: Segmentation fault on long input (list of pairs) -------------------------------------+------------------------------------- Reporter: cathper | Owner: Type: bug | Status: new Priority: high | Milestone: Component: Compiler | Version: 7.0.1 Resolution: | Keywords: Segmentation | fault, segfault, long input Operating System: Linux | Architecture: x86_64 | (amd64) Type of failure: Runtime crash | Test Case: Blocked By: 4258 | Blocking: Related Tickets: | Differential Rev(s): Phab:D1180 Wiki Page: | -------------------------------------+------------------------------------- Changes (by bgamari): * milestone: 8.0.2 => -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/4505#comment:48> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8248: GHCi should not warn if group writable
by GHC 13 Dec '16

13 Dec '16

#8248: GHCi should not warn if group writable ----------------------------+---------------------------------------------- Reporter: afcowie | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: GHCi | Version: 7.6.3 Keywords: | Operating System: Linux Architecture: | Type of failure: GHC rejects valid program Unknown/Multiple | Test Case: Difficulty: Unknown | Blocking: Blocked By: | Related Tickets: | ----------------------------+---------------------------------------------- Any number of Linux distros support the idea of user groups, whereby when a new user is created there is also simultaneously a group created with the same name; ie, instead of {{{ -rw-r--r--. 1 andrew users 19 Sep 5 08:29 ghci.conf }}} as us old traditionalists would have it, you get {{{ -rw-rw-r--. 1 andrew andrew 19 Sep 5 08:29 ghci.conf }}} because the umask in such cases is 0002 instead of 0022. There is entirely nothing unusual or incorrect about this approach, and it is followed, for example, in the Fedora family of distros. GHC, however, is being a bit silly in emitting the following: {{{ $ ghci 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. *** WARNING: /home/andrew/.ghc/ghci.conf is writable by someone else, IGNORING! Prelude> }}} Foremost the fact that the file is group writable is not a problem and the user's choice, //particularly// in this case because it's group writable in the user's group! Regardless of that, GHCi should not be ignoring files with other than 0644 permissions; this isn't `.ssh/`. Can this check and attendant behaviour be removed? AfC -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8248> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #12955: Confusing error (module is not loaded) when more hsigs provided than -instantiated-with
by GHC 13 Dec '16

13 Dec '16

#12955: Confusing error (module is not loaded) when more hsigs provided than -instantiated-with -------------------------------------+------------------------------------- Reporter: ezyang | Owner: ezyang Type: bug | Status: new Priority: normal | Milestone: 8.2.1 Component: Compiler | Version: 8.1 Keywords: backpack | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- Steps to reproduce: 1. Create an `A.hsig` file with `signature A where` 2. Try to build it with `ghc --make A.hsig` Expected: Some error indicating an unexpected signature (you need to specify `-instantiated-with` Actual: This error: {{{ [1 of 1] Compiling A[sig] (.hsig -> .o) attempting to use module ‘main:A’ (A.hsig) which is not loaded }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12955> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #12963: Give -fexpose-all-unfoldings the same semantics as INLINABLE on each function
by GHC 13 Dec '16

13 Dec '16

#12963: Give -fexpose-all-unfoldings the same semantics as INLINABLE on each function -------------------------------------+------------------------------------- Reporter: | Owner: MikolajKonarski | Type: feature | Status: new request | Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: #12962 Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- Feature request: give `-fexpose-all-unfoldings` the same semantics as `INLINABLE` on each function. For simplicity, for the principle of least surprise and for usability of `-fexpose-all-unfoldings`, so that it can actually replace tons of `INLINABLE` that are needed, e.g., for code with lots of abstract class constraints to force it to specialize to the single class that is actually used. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12963> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #12942: Add infix flag for class and data declarations
by GHC 13 Dec '16

13 Dec '16

#12942: Add infix flag for class and data declarations -------------------------------------+------------------------------------- Reporter: alanz | Owner: alanz Type: task | Status: new Priority: normal | Milestone: 8.2.1 Component: Compiler | Version: 8.0.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: #3384 Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- At the moment, data and type declarations using infix formatting produce the same AST as those using prefix. So {{{#!hs type a ++ b = c }}} and {{{#!hs type (++) a b = c }}} cannot be distinguished in the parsed source, without looking at the `OccName` details of the constructor being defined. Having access to the `OccName` requires an additional constraint which explodes out over the entire AST because of its recursive definitions. In keeping with moving the parsed source to more directly reflect the source code as parsed, add a specific flag to the declaration to indicate the fixity, as used in a `Match` now too. Note: this flag is to capture the fixity used for the lexical definition of the type, primarily for use by `ppr` and `ghc-exactprint`. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12942> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #12936: Type inference regression in GHC HEAD
by GHC 13 Dec '16

13 Dec '16

#12936: Type inference regression in GHC HEAD -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: Type: bug | Status: new Priority: high | Milestone: 8.2.1 Component: Compiler | Version: 8.1 (Type checker) | Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: GHC rejects Unknown/Multiple | valid program Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- First noticed in https://ghc.haskell.org/trac/ghc/ticket/12790#comment:8. This causes `parsec-3.1.11` to fail to build with GHC HEAD. Here is as small of a test case that I can manage, with no dependencies: {{{#!hs {-# LANGUAGE FlexibleContexts #-} {-# LANGUAGE FunctionalDependencies #-} {-# LANGUAGE KindSignatures #-} {-# LANGUAGE MultiParamTypeClasses #-} module Parsec (makeTokenParser) where import Data.Char (digitToInt) data ParsecT s u (m :: * -> *) a instance Functor (ParsecT s u m) where fmap = undefined instance Applicative (ParsecT s u m) where pure = undefined (<*>) = undefined instance Monad (ParsecT s u m) where return = undefined (>>=) = undefined fail = undefined parserZero :: ParsecT s u m a parserZero = undefined infixr 1 <|> (<|>) :: (ParsecT s u m a) -> (ParsecT s u m a) -> (ParsecT s u m a) (<|>) = undefined class (Monad m) => Stream s m t | s -> t where digit :: (Stream s m Char) => ParsecT s u m Char digit = undefined hexDigit :: (Stream s m Char) => ParsecT s u m Char hexDigit = undefined octDigit :: (Stream s m Char) => ParsecT s u m Char octDigit = undefined option :: (Stream s m t) => a -> ParsecT s u m a -> ParsecT s u m a option = undefined many1 :: (Stream s m t) => ParsecT s u m a -> ParsecT s u m [a] many1 = undefined data GenTokenParser s u m = TokenParser { float :: ParsecT s u m Double, naturalOrFloat :: ParsecT s u m (Either Integer Double) } makeTokenParser :: (Stream s m Char) => GenTokenParser s u m makeTokenParser = TokenParser{ float = float_ , naturalOrFloat = naturalOrFloat_ } where ----------------------------------------------------------- -- Numbers ----------------------------------------------------------- naturalOrFloat_ = lexeme natFloat float_ = lexeme floating -- floats floating = do{ n <- decimal ; fractExponent n } natFloat = zeroNumFloat <|> decimalFloat zeroNumFloat = do{ n <- hexadecimal <|> octal ; return (Left n) } <|> decimalFloat decimalFloat = do{ n <- decimal ; option (Left n) (fractFloat n) } fractFloat n = do{ f <- fractExponent n ; return (Right f) } fractExponent n = do{ fract <- fraction ; expo <- option "" exponent' ; readDouble (show n ++ fract ++ expo) } <|> do{ expo <- exponent' ; readDouble (show n ++ expo) } where readDouble s = case reads s of [(x, "")] -> return x _ -> parserZero fraction = do{ digits <- many1 digit ; return ('.' : digits) } exponent' = do{ e <- decimal ; return (show e) } -- integers and naturals decimal = number 10 digit hexadecimal = number 16 hexDigit octal = number 8 octDigit number base baseDigit = do{ digits <- many1 baseDigit ; let n = foldl (\x d -> base*x + toInteger (digitToInt d)) 0 digits ; seq n (return n) } ----------------------------------------------------------- -- White space & symbols ----------------------------------------------------------- lexeme p = do{ x <- p; whiteSpace; return x } whiteSpace = return () }}} In GHC 8.0.1 and 8.0.2, this compiles without issue. But on GHC HEAD: {{{ $ ~/Software/ghc/inplace/bin/ghc-stage2 Parsec.hs [1 of 1] Compiling Parsec ( Parsec.hs, Parsec.o ) Parsec.hs:83:27: error: • Could not deduce (Stream s m t0) arising from a use of ‘option’ from the context: Stream s m Char bound by the type signature for: makeTokenParser :: Stream s m Char => GenTokenParser s u m at Parsec.hs:53:1-60 The type variable ‘t0’ is ambiguous Relevant bindings include decimalFloat :: ParsecT s u1 m (Either Integer Double) (bound at Parsec.hs:82:5) fractFloat :: forall b a1 u a2. (Read b, Show a2) => a2 -> ParsecT s u m (Either a1 b) (bound at Parsec.hs:87:5) fractExponent :: forall a1 u a2. (Show a2, Read a1) => a2 -> ParsecT s u m a1 (bound at Parsec.hs:91:5) fraction :: forall u. ParsecT s u m [Char] (bound at Parsec.hs:105:5) exponent' :: forall u. ParsecT s u m String (bound at Parsec.hs:109:5) decimal :: forall u. ParsecT s u m Integer (bound at Parsec.hs:114:5) lexeme :: forall b. ParsecT s u m b -> ParsecT s u m b (bound at Parsec.hs:127:5) (Some bindings suppressed; use -fmax-relevant-binds=N or -fno-max- relevant-binds) • In a stmt of a 'do' block: option (Left n) (fractFloat n) In the expression: do { n <- decimal; option (Left n) (fractFloat n) } In an equation for ‘decimalFloat’: decimalFloat = do { n <- decimal; option (Left n) (fractFloat n) } }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12936> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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