May 2017 - ghc-tickets

Re: [GHC] #5546: Documentation errors in Control.Exception.Base
by GHC 07 May '17

07 May '17

#5546: Documentation errors in Control.Exception.Base -------------------------------------+------------------------------------- Reporter: bit | Owner: (none) Type: bug | Status: closed Priority: high | Milestone: 8.2.1 Component: libraries/base | Version: 8.0.1 Resolution: fixed | 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): * status: new => closed * resolution: => fixed * milestone: ⊥ => 8.2.1 -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/5546#comment:6> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8101: No pattern match non-exhaustiveness warnings when compiling with -fno-code
by GHC 07 May '17

07 May '17

#8101: No pattern match non-exhaustiveness warnings when compiling with -fno-code -------------------------+------------------------------------------------- Reporter: exbb2 | Owner: Type: bug | Status: new Priority: | Milestone: normal | Version: 7.6.3 Component: | Operating System: Unknown/Multiple Compiler | Type of failure: Incorrect warning at Keywords: | compile-time Architecture: | Test Case: Unknown/Multiple | Blocking: Difficulty: | Unknown | Blocked By: | Related Tickets: | -------------------------+------------------------------------------------- {{{ {-# OPTIONS_GHC -Wall #-} module A where data ABC = A | B | C abc :: ABC -> Int abc x = case x of A -> 1 }}} {{{ $ ghc -fno-code -fforce-recomp /tmp/A.hs [1 of 1] Compiling A ( /tmp/A.hs, nothing ) }}} {{{ $ ghc -fobject-code -fforce-recomp /tmp/A.hs [1 of 1] Compiling A ( /tmp/A.hs, /tmp/A.o ) /tmp/A.hs:7:9: Warning: Pattern match(es) are non-exhaustive In a case alternative: Patterns not matched: B C }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8101> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #4858: Add Control.Concurrent.forkIOWithUnmask, deprecate forkIOUnmasked
by GHC 07 May '17

07 May '17

#4858: Add Control.Concurrent.forkIOWithUnmask, deprecate forkIOUnmasked -------------------------------------+--------------------------------- Reporter: simonmar | Owner: (none) Type: proposal | Status: closed Priority: normal | Milestone: Not GHC Component: libraries/base | Version: 7.0.1 Resolution: invalid | Keywords: Operating System: Unknown/Multiple | Architecture: Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: -------------------------------------+--------------------------------- Comment (by Ben Gamari <ben@…>): In [changeset:"1840121078718fb2a2fe5a7895501100517f627c/ghc" 1840121/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="1840121078718fb2a2fe5a7895501100517f627c" base: Fix documentation for forkIOWithUnmask forkIOUnmasked has been deprecated for several years now. Update reference to it. See #4858 and #5546. }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/4858#comment:6> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #5546: Documentation errors in Control.Exception.Base
by GHC 07 May '17

07 May '17

#5546: Documentation errors in Control.Exception.Base -------------------------------------+------------------------------------- Reporter: bit | Owner: (none) Type: bug | Status: new Priority: high | Milestone: ⊥ Component: libraries/base | Version: 8.0.1 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 Ben Gamari <ben@…>): In [changeset:"1840121078718fb2a2fe5a7895501100517f627c/ghc" 1840121/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="1840121078718fb2a2fe5a7895501100517f627c" base: Fix documentation for forkIOWithUnmask forkIOUnmasked has been deprecated for several years now. Update reference to it. See #4858 and #5546. }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/5546#comment:5> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #13590: Update Cabal submodule to whatever the final Cabal 2.0 release is
by GHC 07 May '17

07 May '17

#13590: Update Cabal submodule to whatever the final Cabal 2.0 release is -------------------------------------+------------------------------------- Reporter: ezyang | Owner: (none) Type: bug | Status: new Priority: highest | Milestone: 8.2.1 Component: libraries | Version: 8.2.1-rc2 (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 release blocker and I want to file it here so we don't forget. In fact, 2.0 head has already diverged from 8.2.1-rc1, see https://github.com/haskell/cabal/issues/4453 for some fall out (since we now have multiple "2.0" Cabals floating around. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13590> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #13660: Tail after and including `NUL` character in `FilePath`s silently truncated
by GHC 07 May '17

07 May '17

#13660: Tail after and including `NUL` character in `FilePath`s silently truncated -------------------------------------+------------------------------------- Reporter: hvr | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: | Version: 8.0.2 libraries/base | 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: -------------------------------------+------------------------------------- The current behaviour is imho not ideal as it masks invalid input arguments; consider e.g. {{{#!hs Prelude> readFile "foo" *** Exception: foo: openFile: does not exist (No such file or directory) Prelude> readFile "foo\NULbar" *** Exception: foobar: openFile: does not exist (No such file or directory) Prelude> writeFile "foo\NULbar" "contents" Prelude> readFile "foo\NULbar" "contents" Prelude> readFile "foo" "contents" }}} The reason for the surprising behaviour above is most likely (I haven't yet looked at the code), that `"foo\NULbar"` gets converted into a zero- terminated `CString` which is then passed to C functions such as `fopen(3)`, but to those C function, the C strings `"foo\0bar"` and `"foo"` are equivalent, as both are interpreted as `"foo"`. What I'd expect to happen on POSIX systems is that operations taking a `FilePath` such as `writeFile` or `readFile` should throw an exception when the `FilePath` gets encoded in such a way into a zero-terminated CString in such a way that a zero octet occurs (except for the intended zero-termination zero octet at the end). -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13660> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #13656: Consider implementing atomicModifyMutVar# in Haskell
by GHC 07 May '17

07 May '17

#13656: Consider implementing atomicModifyMutVar# in Haskell -------------------------------------+------------------------------------- Reporter: dfeuer | Owner: (none) Type: task | Status: new Priority: low | Milestone: 8.4.1 Component: Runtime | Version: 8.2.1-rc2 System | 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: -------------------------------------+------------------------------------- I believe we could implement `atomicModifyMutVar#` in Haskell, rather than making it a primop. This seems like a simpler/cleaner approach (among other things, it gets a perfectly legitimate type signature!), but we'd have to see how it affects performance. I think something like this should work: {{{#!hs atomicModifyMutVar# :: MutVar# s a -> (a -> (a,b)) -> State# s -> (# State# s, b #) atomicModifyMutVar# mv f s = case readMutVar# mv s of { (# s', old #) -> let f_old = f old in case casMutVar# mv old (fst $ f_old) s of { (# s', unchanged, new #) -> case unchanged of 0# -> (# s', snd f_old #) _ -> atomicModifyMutVar# mv f s' }} }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13656> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10431: EqualityConstraints extension?
by GHC 06 May '17

06 May '17

#10431: EqualityConstraints extension? -------------------------------------+------------------------------------- Reporter: adamgundry | Owner: Type: feature | Status: new request | Milestone: 7.12.1 Priority: normal | Version: 7.11 Component: Compiler | Operating System: Unknown/Multiple (Type checker) | Type of failure: None/Unknown Keywords: | Blocked By: Architecture: | Related Tickets: Unknown/Multiple | Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- At the moment, writing an equality constraint in a type requires at least one of the `GADTs` or `TypeFamilies` extensions. However, each of these has other effects. Could we have an `EqualityConstraints` extension to permit equality constraints in types, but neither GADTs nor type families? Presumably this extension should imply `MonoLocalBinds`. The `GADTs` extension could then become precisely the conjunction of `GADTSyntax`, `EqualityConstraints` and `ExistentialQuantification`. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10431> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #12947: Core lint error
by GHC 06 May '17

06 May '17

#12947: Core lint error -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: Type: bug | Status: new 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: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- {{{#!hs import qualified Control.Monad.Fail as Fail newtype P m a = P { unP :: (a -> IO (m ())) -> IO (m ()) } instance Functor (P m) where instance Applicative (P m) where instance Monad (P m) where instance (Fail.MonadFail m) => Fail.MonadFail (P m) where fail msg = ContT $ \ _ -> Fail.fail msg }}} fails when run with `$ ghci -ignore-dot-ghci -fdefer-typed-holes -dcore- lint /tmp/tQZR.hs`, log is attached -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12947> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #13640: Core lint error with deferred type holes
by GHC 06 May '17

06 May '17

#13640: Core lint error with deferred type holes -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: (none) Type: bug | Status: new 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: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- {{{#!hs {-# Options_GHC -dcore-lint -fdefer-typed-holes #-} import Prelude hiding ((.)) class Functor' f where map' :: (a -> b) -> f a -> f b class Bifunctor' f where map2' :: (a -> b) -> f a c -> f b c bimap' :: Bifunctor' f => (a -> b) -> (c -> d) -> (f a c -> f b d) bimap' f g = map2' f . map' }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13640> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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