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[GHC] #13682: When printf "%g" with trailing 0 number, decial point be printed.
by GHC 13 May '17

13 May '17

#13682: When printf "%g" with trailing 0 number, decial point be printed. ----------------------------------------+--------------------------------- Reporter: nakaji_dayo | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: libraries/base | Version: 8.0.1 Keywords: printf | Operating System: MacOS X Architecture: Unknown/Multiple | Type of failure: None/Unknown Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: ----------------------------------------+--------------------------------- C lang's printf function doesn't print decimal point if only trailing 0s. But GHC does. {{{ Prelude Text.Printf> :m + Text.Printf Prelude Text.Printf> printf "%g\n" 2.0 2.0 }}} {{{ #include <stdio.h> int main() { printf("%g\n", 2.0); return 0; } // output: 2 }}} Is this bug? Should printf be compatible with C? -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13682> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #12962: No automatic SCC annotations for functions marked INLINABLE
by GHC 12 May '17

12 May '17

#12962: No automatic SCC annotations for functions marked INLINABLE -------------------------------------+------------------------------------- Reporter: | Owner: MikolajKonarski | Type: bug | Status: new Priority: normal | Milestone: Component: Profiling | 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: -------------------------------------+------------------------------------- Judging from .prof files and the -xc and -prof callstacks, GHC adds no automatic SCC annotations for functions marked `INLINABLE`. The user's guide only mentions `INLINE`: https://downloads.haskell.org/~ghc/latest/docs/html/users_guide/profiling.h…, not `INLINABLE`. Is it a bug in documentation or implementation? In my case I managed to work around by using `-fexpose-all-unfoldings` instead of the tons of `INLINABLE` I was using before, but in general case, adding all the SCC annotations by hand seems prohibitive. e.g., in code that needs a lot of `INLINABLE` to enable specialization. Since `-fexpose-all-unfoldings` does not inhibit profiling and compiling with no optimization doesn't help recover it, the culprit is probably not the actual inlining or specialization, but rather handling of the `INLINABLE` pragma itself. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12962> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11964: Without TypeInType, inconsistently accepts Data.Kind.Type but not type synonym
by GHC 12 May '17

12 May '17

#11964: Without TypeInType, inconsistently accepts Data.Kind.Type but not type synonym -------------------------------------+------------------------------------- Reporter: ezyang | Owner: goldfire Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1-rc2 (Type checker) | 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 convenience, I'll use GHCi to demonstrate flag behavior. First, we define a file: ``` {-# LANGUAGE TypeInType #-} import Data.Kind type Star = Type newtype T k (t :: k) = T () ``` Next, we load it up in GHCi, WITHOUT `-XTypeInType`. Now we observe strange behavior: ``` ezyang@sabre:~$ ghc-8.0 --interactive C.hs GHCi, version 8.0.0.20160204: http://www.haskell.org/ghc/ :? for help [1 of 1] Compiling Main ( C.hs, interpreted ) Ok, modules loaded: Main. *Main> :k T Type Int T Type Int :: * *Main> :k T Star Int <interactive>:1:3: error: • Data constructor ‘Star’ cannot be used here (Perhaps you intended to use DataKinds) • In the first argument of ‘T’, namely ‘Star’ In the type ‘T Star Int’ ``` Of course, if we pass `-TypeInType` to GHCi that fixes the problem (BTW, `DataKinds` does NOT solve the problem.) -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11964> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11966: Surprising behavior with higher-rank quantification of kind variables
by GHC 12 May '17

12 May '17

#11966: Surprising behavior with higher-rank quantification of kind variables -------------------------------------+------------------------------------- Reporter: ocharles | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1-rc3 (Type checker) | Keywords: TypeInType | 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: -------------------------------------+------------------------------------- Sorry about the rubbish title. I wrote the following code, which type checks: {{{#!hs {-# LANGUAGE TypeFamilies #-} {-# LANGUAGE DataKinds #-} {-# LANGUAGE KindSignatures #-} {-# LANGUAGE PolyKinds #-} {-# LANGUAGE RankNTypes #-} {-# LANGUAGE TypeInType #-} {-# LANGUAGE TypeOperators #-} module Test where import Data.Kind (Type) -- Simplification type family Col (f :: k -> j) (x :: k) :: Type -- Base types data PGBaseType = PGInteger | PGText -- Transformations data Column t = Column Symbol t newtype Nullable t = Nullable t newtype HasDefault t = HasDefault t -- Interpretations data Expr k data Record (f :: forall k. k -> Type) = Record {rX :: Col f ('Column "x" 'PGInteger) ,rY :: Col f ('Column "y" ('Nullable 'PGInteger)) ,rZ :: Col f ('HasDefault 'PGText)} }}} However, if I play with this in GHCI, I can get the following error: {{{ λ> let x = undefined :: Record Expr <interactive>:136:29-32: error: • Expected kind ‘forall k. k -> Type’, but ‘Expr’ has kind ‘forall k. k -> *’ • In the first argument of ‘Record’, namely ‘Expr’ In an expression type signature: Record Expr In the expression: undefined :: Record Expr }}} It seems that if I write {{{#!hs data Expr :: forall k. k -> Type }}} things work, but I'm unclear if/why that is necessary, and the error message certainly needs to be fixed. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11966> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #12083: ghc-8.0.1-rc4: tyConRoles sees a TcTyCon
by GHC 12 May '17

12 May '17

#12083: ghc-8.0.1-rc4: tyConRoles sees a TcTyCon -------------------------------------+------------------------------------- Reporter: _deepfire | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1-rc4 (Type checker) | Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Compile-time Unknown/Multiple | crash Test Case: Yes. | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- {{{#!hs {-# LANGUAGE TypeFamilies #-} {-# LANGUAGE UnicodeSyntax #-} import Prelude.Unicode type Constrd a = Num a ⇒ a data ADT a = ADT (Constrd a) ExistentiallyLost data ExistentiallyLost = ∀ u. TC u ⇒ ExistentiallyLost u class u ~ (ATF1 u, ATF2 u) ⇒ TC u where type ATF1 u ∷ * type ATF2 u ∷ * uie_handlers ∷ ADT Int -- Loop: -- - ADT depends on ExistentiallyLost (also the Constrd appendage) -- - ExistentiallyLost depends on TC -- - TC depends on ADT }}} --> {{{ [1 of 1] Compiling Main ( /home/deepfire/src/ghc-testcases /tyconroles-sees-a-tctycon-tyalias.hs, interpreted ) <- ghc: panic! (the 'impossible' happened) (GHC version 8.0.0.20160421 for x86_64-unknown-linux): tyConRoles sees a TcTyCon Constrd Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12083> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #13271: GHC Panic With Injective Type Families
by GHC 12 May '17

12 May '17

#13271: GHC Panic With Injective Type Families ----------------------------------------+--------------------------------- Reporter: wayofthepie | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 Keywords: | Operating System: Linux Architecture: Unknown/Multiple | Type of failure: None/Unknown Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: ----------------------------------------+--------------------------------- The following causes GHC to panic: {{{ {-# LANGUAGE DataKinds #-} {-# LANGUAGE TypeFamilyDependencies #-} module T where import GHC.TypeLits data T1 = T1 type T2 = TypeError (Text "You can't do that!") type family X i = r | r -> i where X 1 = T1 X 2 = T2 }}} {{{ $ ghc T.hs [1 of 1] Compiling T ( T.hs, T.o ) ghc: panic! (the 'impossible' happened) (GHC version 8.0.1 for x86_64-unknown-linux): isInjectiveTyCon sees a TcTyCon T2 }}} This may be related to https://ghc.haskell.org/trac/ghc/ticket/11560. Without injectivity it gives the expected type error with the message "You can't do that!" {{{ {-# LANGUAGE DataKinds #-} {-# LANGUAGE TypeFamilies #-} module T where import GHC.TypeLits data T1 = T1 type T2 = TypeError (Text "You can't do that!") type family X i where X 1 = T1 X 2 = T2 }}} {{{ $ ghc T.hs [1 of 1] Compiling T ( T.hs, T.o ) T.hs:9:1: error: • You can't do that • In the type synonym declaration for ‘T2’ }}} This isn't something anyone would intentionally write, as it could never type check with the type synonym T2 being a TypeError, but a panic is a panic so I said I'd raise it anyway. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13271> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #13545: Remove duplication between lookupSubBndrOcc and lookupExportChild
by GHC 11 May '17

11 May '17

#13545: Remove duplication between lookupSubBndrOcc and lookupExportChild -------------------------------------+------------------------------------- Reporter: mpickering | Owner: (none) Type: task | 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: -------------------------------------+------------------------------------- `lookupSubBndrOcc` is used in expressions such as `x { y = 5 }` to resolve field labels such as `y`. `lookupExportChild` is used in export lists such as `T(A, x)` to lookup `A` and `x`. They contain very similar logic but it is duplicated in two places which caused #13528. It should be easy to refactor them them to deduplicate the logic. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13545> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #13688: Allow splices in definition of pattern synonym
by GHC 11 May '17

11 May '17

#13688: Allow splices in definition of pattern synonym -------------------------------------+------------------------------------- Reporter: bgamari | Owner: (none) Type: feature | Status: new request | Priority: normal | Milestone: Component: Template | Version: 8.0.1 Haskell | Keywords: | Operating System: Unknown/Multiple PatternSynonyms | Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- shlevy requests the ability to write, {{{#!hs pattern MyUUID = [uuid|dbf20a11-b04a-47a5-a7d6-a6f9ae7ff895|] }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13688> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #13417: piResultTys1
by GHC 11 May '17

11 May '17

#13417: piResultTys1 -------------------------------------+------------------------------------- Reporter: ralf | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.2 Keywords: | Operating System: Linux Architecture: x86_64 | Type of failure: Compile-time (amd64) | crash or panic Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- Error provoked by attached H98 program (which is generated by a program); compiles fine without optimizations; compilation with -O2 crashes: $ ghc --make -O2 FactorialSequ.lhs [1 of 1] Compiling FactorialSequ ( FactorialSequ.lhs, FactorialSequ.o ) ghc: panic! (the 'impossible' happened) (GHC version 8.0.2 for x86_64-unknown-linux): piResultTys1 Sequ7 t_a2zl [a_a2zm] -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13417> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11722: No TypeRep for unboxed tuples
by GHC 11 May '17

11 May '17

#11722: No TypeRep for unboxed tuples -------------------------------------+------------------------------------- Reporter: goldfire | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.1 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: -------------------------------------+------------------------------------- This now crashes on GHC HEAD: {{{#!hs {-# LANGUAGE MagicHash #-} {-# LANGUAGE UnboxedTuples #-} module Main where import Data.Typeable import GHC.Exts main :: IO () main = print $ typeOf (Proxy :: Proxy (# Int, Int #)) }}} {{{ $ /opt/ghc/head/bin/ghc -O2 -fforce-recomp Example.hs [1 of 1] Compiling Main ( Example.hs, Example.o ) ghc: panic! (the 'impossible' happened) (GHC version 8.1.20160317 for x86_64-unknown-linux): tyConRep (#,#) Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} (Previously, this was rejected with an error message, since you couldn't put an unlifted type as the argument of `Proxy`.) (Copied from comment:28:ticket:11471.) -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11722> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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