February 2019 - ghc-tickets

[GHC] #11004: hsc2hs does not handle single quotes properly
by GHC 01 Feb '19

01 Feb '19

#11004: hsc2hs does not handle single quotes properly -------------------------------------+------------------------------------- Reporter: sergv | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: hsc2hs | 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: -------------------------------------+------------------------------------- The tool gets confused by quotes for promoted constructors (https://downloads.haskell.org/~ghc/latest/docs/html/users_guide/promotion.h… #promotion-syntax). Here's an example: {{{#!hs {-# LANGUAGE DataKinds #-} {-# LANGUAGE GADTs #-} data Foo = Foo | Bar data Indexed ix where Indexed :: Indexed 'Foo main :: IO () main = print $ #size int }}} gets translated into {{{#!hs {-# LINE 1 "Test.hsc" #-} {-# LANGUAGE DataKinds #-} {-# LINE 2 "Test.hsc" #-} {-# LANGUAGE GADTs #-} data Foo = Foo | Bar data Indexed ix where Indexed :: Indexed 'Foo main :: IO () main = print $ #size int }}} Then GHC complains about `#size`: {{{ Test.hsc:10:16: parse error on input ‘#’ }}} Judging from the source of utils/hsc2hs/HSCParser.hs, the tool treats single quotes the same way as double quotes. I.e. it looks for balanced, possibly multiline, strings delimited by '. At least, it seems unnecessary to expect newlines in that string-like structure, because character literals cannot contain newlines, AFAIK. It's interesting to note that this problem looks like a bit of an edge case, since highlighting in the ticket seems to be confused as well. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11004> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #15514: Older Trac ticket links redirect to this site, but not to the specific ticket
by GHC 01 Feb '19

01 Feb '19

#15514: Older Trac ticket links redirect to this site, but not to the specific ticket -------------------------------------+------------------------------------- Reporter: ChaiTRex | Owner: hvr Type: bug | Status: new Priority: normal | Milestone: Component: Trac & Git | Version: 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: -------------------------------------+------------------------------------- == Current behavior == An old ticket link is redirected to this new site, just not to the actual ticket, so some form of redirection is configured: || ||= old link =||= redirects to =|| ||= HTTP =|| http://hackage.haskell.org/trac/ghc/ticket/698 || https://ghc.haskell.org/trac/ghc || ||= HTTPS =|| https://hackage.haskell.org/trac/ghc/ticket/698 || https://ghc.haskell.org/trac/ghc || == Desired outcome == An old ticket link should redirect to the actual ticket: || ||= old link =||= redirects to =|| ||= HTTP =|| http://hackage.haskell.org/trac/ghc/ticket/698 || https://ghc.haskell.org/trac/ghc/ticket/698 || ||= HTTPS =|| https://hackage.haskell.org/trac/ghc/ticket/698 || https://ghc.haskell.org/trac/ghc/ticket/698 || -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15514> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #16276: Feature request: Polymorphic kinds in Data.Functor.Classes
by GHC 01 Feb '19

01 Feb '19

#16276: Feature request: Polymorphic kinds in Data.Functor.Classes -------------------------------------+------------------------------------- Reporter: siddharthist | Owner: (none) Type: feature | Status: new request | Priority: normal | Milestone: Component: Compiler | Version: 8.6.3 Keywords: polykinds | 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 classes in Data.Functor.Classes have a somewhat restrictive kind signature: {{{ *Data.Functor.Classes> :k Eq1 Eq1 :: (* -> *) -> Constraint }}} As a result, we redefine [1] many of them in the [https://hackage.haskell.org/package/parameterized-utils-1.0.1/docs/Data- Parameterized-Classes.html parameterized-utils] library. It would be quite easy to make more polymorphic (have kind "(k -> *) -> Constraint"). If everyone thinks this is a good idea, I'm happy to submit a pull request. [1]: To be precise, there are actually a few axes along which the classes in parameterized-utils vary from those in base. Some, like OrdF, require more type-level evidence. Others, like EqF, don't require their type parameter to have the corresponding instance. There are a lot of points in the design space here. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/16276> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #16275: type hole in hs-boot file triggers GHC internal error
by GHC 01 Feb '19

01 Feb '19

#16275: type hole in hs-boot file triggers GHC internal error -------------------------------------+------------------------------------- Reporter: j.waldmann | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.6.3 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: -------------------------------------+------------------------------------- Put each line in a separate file, the last one is B.hs-boot {{{ module A where { import {-# SOURCE #-} B } module B where { } module B where { data T a ; foo :: T _ } }}} then {{{ $ ghci A.hs GHCi, version 8.6.3: http://www.haskell.org/ghc/ :? for help [1 of 3] Compiling B[boot] ( B.hs-boot, interpreted ) B.hs-boot:1:38: error: • GHC internal error: ‘_’ is not in scope during type checking, but it passed the renamer tcl_env of environment: [] • In the first argument of ‘T’, namely ‘_’ In the type signature: foo :: T _ | 1 | module B where { data T a ; foo :: T _ } | ^ }}} I know the program is invalid (the hole has no valid instance) but still it should not produce an internal error? -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/16275> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #16273: Hadrian turns on `-Wno-unused-imports` for text when using integer-simple
by GHC 01 Feb '19

01 Feb '19

#16273: Hadrian turns on `-Wno-unused-imports` for text when using integer-simple -------------------------------------+------------------------------------- Reporter: mpickering | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Build System | Version: 8.6.3 (Hadrian) | Keywords: newcomer | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- In `Settings.Warnings`, hadrian turns on `-Wno-unused-imports` for the `text` package when building with `integer-simple`. It would be good to fix `text` so we can remove this special case. 1. Build GHC with `integer-simple` and `-Werror` 2. Remove the special case for `text` in `Settings.Warnings`. 3. Fix the warnings in `text` appropriately so the build finishes. 4. Push the fix upstream and then update the submodule. This could also be debugged without having to build ghc by downloading an [https://gitlab.haskell.org/ghc/ghc/-/jobs/artifacts/master/download?job =validate-x86_64-linux-deb9-integer-simple integer-simple bindist]. Also see: https://github.com/haskell/text/issues/250 -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/16273> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #16216: readHexRational missing from Numeric
by GHC 01 Feb '19

01 Feb '19

#16216: readHexRational missing from Numeric -------------------------------------+------------------------------------- Reporter: merijn | Owner: (none) Type: feature | Status: new request | Priority: normal | Milestone: Component: | Version: 8.6.3 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 HexFloatLiterals extension was merged as result of https://github.com /ghc-proposals/ghc-proposals/blob/master/proposals/0004-hexFloats.rst As part of this proposal `showHFloat` was added to Numeric to output floating points in hexFloat format, unfortunately, no one seems to have remembered to add `readHexRational` or a similar function to parse hexFloats to Numeric. This leads to the awkward scenario that I can easily produce hexFloat values, but have no way to parse them from `String`/`Text` data... All the code already exists in `compiler/util/Utils.hs`, someone just needs to cherry pick the implementation add add it to Numeric in base. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/16216> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #16268: Potential race condition in Hadrian?
by GHC 01 Feb '19

01 Feb '19

#16268: Potential race condition in Hadrian? -------------------------------------+------------------------------------- Reporter: mpickering | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.6.3 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: -------------------------------------+------------------------------------- It seems that sometimes CI jobs fail because of a race condition in Hadrian. https://gitlab.haskell.org/ghc/ghc/-/jobs/20254 Here, array finishes before `deepseq` starts to be built but the configure step for `deepseq` fails to find the library. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/16268> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #16152: Core lint error from PartialTypeSignatures
by GHC 01 Feb '19

01 Feb '19

#16152: Core lint error from PartialTypeSignatures -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.7 Keywords: | Operating System: Unknown/Multiple PartialTypeSignatures | Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- {{{#!hs {-# Language PartialTypeSignatures #-} {-# Language PolyKinds #-} {-# Language ScopedTypeVariables #-} {-# Options_GHC -dcore-lint #-} top :: forall f. _ top = undefined where x :: forall a. f a x = undefined }}} causes Core lint errors: {{{ $ ~/../inplace/bin/ghc-stage2 --interactive -ignore-dot-ghci 922_bug.hs GHCi, version 8.7.20181230: https://www.haskell.org/ghc/ :? for help [1 of 1] Compiling Main ( 922_bug.hs, interpreted ) *** Core Lint errors : in result of Desugar (before optimization) *** <no location info>: warning: In the type ‘forall (f :: k_a1z6 -> *) w. w’ @ k_a1z6 is out of scope *** Offending Program *** Rec { $trModule :: Module [LclIdX] $trModule = Module (TrNameS "main"#) (TrNameS "Main"#) top :: forall (f :: k_a1z6 -> *) w. w [LclIdX] top = \ (@ (f_a2BY :: k_a1z6 -> *)) (@ w_a2BZ) -> (\ (@ k_a1z6) (@ (f_a1yV :: k_a1z6 -> *)) (@ w_a1yN) -> let { $dIP_a2BO :: ?callStack::CallStack [LclId] $dIP_a2BO = emptyCallStack `cast` (Sym (N:IP[0] <"callStack">_N <CallStack>_N) :: CallStack ~R# (?callStack::CallStack)) } in let { $dIP_a2BD :: HasCallStack [LclId] $dIP_a2BD = (pushCallStack (unpackCString# "undefined"#, SrcLoc (unpackCString# "main"#) (unpackCString# "Main"#) (unpackCString# "922_bug.hs"#) (I# 8#) (I# 7#) (I# 8#) (I# 16#)) ($dIP_a2BO `cast` (N:IP[0] <"callStack">_N <CallStack>_N :: (?callStack::CallStack) ~R# CallStack))) `cast` (Sym (N:IP[0] <"callStack">_N <CallStack>_N) :: CallStack ~R# (?callStack::CallStack)) } in letrec { top_a1yW :: w_a1yN [LclId] top_a1yW = letrec { x_a1yv :: forall (a :: k_a1z6). f_a1yV a [LclId] x_a1yv = \ (@ (a_a1zd :: k_a1z6)) -> let { $dIP_a2BP :: ?callStack::CallStack [LclId] $dIP_a2BP = emptyCallStack `cast` (Sym (N:IP[0] <"callStack">_N <CallStack>_N) :: CallStack ~R# (?callStack::CallStack)) } in let { $dIP_a2Bz :: HasCallStack [LclId] $dIP_a2Bz = (pushCallStack (unpackCString# "undefined"#, SrcLoc (unpackCString# "main"#) (unpackCString# "Main"#) (unpackCString# "922_bug.hs"#) (I# 11#) (I# 7#) (I# 11#) (I# 16#)) ($dIP_a2BP `cast` (N:IP[0] <"callStack">_N <CallStack>_N :: (?callStack::CallStack) ~R# CallStack))) `cast` (Sym (N:IP[0] <"callStack">_N <CallStack>_N) :: CallStack ~R# (?callStack::CallStack)) } in break<0>() undefined @ 'LiftedRep @ (f_a1yV a_a1zd) $dIP_a2Bz; } in break<1>() undefined @ 'LiftedRep @ w_a1yN $dIP_a2BD; } in top_a1yW) @ Any @ Any @ w_a2BZ end Rec } *** End of Offense *** <no location info>: error: Compilation had errors *** Exception: ExitFailure 1 > }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/16152> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #16267: EXTRA_HC_OPTS workflow under hadrian.
by GHC 01 Feb '19

01 Feb '19

#16267: EXTRA_HC_OPTS workflow under hadrian. -------------------------------------+------------------------------------- Reporter: AndreasK | Owner: (none) Type: feature | Status: new request | Priority: normal | Milestone: Component: Build System | Version: 8.6.3 (Hadrian) | 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 allows passing of arbitrary flags to ghc from the command line. The main use case for me so far is to generate dumps for an arbitrary combination of dump flags. Sometimes I wanted to look at the simplifier output for a certain file. Sometimes I wanted to dump the asm code for all files to see how common certain patterns are. Sometimes the same for Cmm. Sometimes I want to dump two passes to be able to cross reference between them. These are usually on-off things and the exact flags often differ. So imo custom build profiles are not a good solution for this. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/16267> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #13834: Error cascade with type applications
by GHC 01 Feb '19

01 Feb '19

#13834: Error cascade with type applications -------------------------------------+------------------------------------- Reporter: mpickering | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 Keywords: newcomer, | Operating System: Unknown/Multiple TypeApplications | Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- Using type applications with an out of scope identifier causes an unfortunate error cascade. {{{ foo = notInScope @Bool }}} Leads to the right out of scope error but also an error about using type application when `notInScope` is not a polytype. I think the second error should be suppressed. {{{ t.hs:4:7: error: Variable not in scope: notInScope | 4 | foo = notInScope @Bool | ^^^^^^^^^^ t.hs:4:7: error: • Cannot apply expression of type ‘t1’ to a visible type argument ‘Bool’ notInScope • In the expression: notInScope @Bool In an equation for ‘foo’: foo = notInScope @Bool | 4 | foo = notInScope @Bool | ^^^^^^^^^^^^^^^^ }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13834> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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