April 2015 - ghc-tickets

[GHC] #10344: Make BranchList simpler
by GHC 24 Apr '15

24 Apr '15

#10344: Make BranchList simpler -------------------------------------+------------------------------------- Reporter: goldfire | Owner: goldfire Type: task | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.11 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Blocked By: Test Case: | Related Tickets: Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- As Adam Gundry suggested, `BranchList` could be made much simpler by actually storing a list in the `Branched` case. Though, as I'm thinking about it, what's better about a real list over a `BranchList`? We're more familiar with it... but perhaps adding a `Foldable` instance for `BranchList` would solve the problem. In any case, this ticket is to record the desire for improvement. If Adam is up to it, he may fix this with Phab:D841. Otherwise, I'll get to it. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10344> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10304: Bump Cabal submodule
by GHC 23 Apr '15

23 Apr '15

#10304: Bump Cabal submodule -------------------------------------+------------------------------------- Reporter: luite | Owner: Type: task | Status: new Priority: normal | Milestone: 7.10.2 Component: Compiler | Version: 7.10.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Blocked By: Test Case: | Related Tickets: Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- Unfortunately 7.10.1 was released with a Cabal library that has a major bug handling ghcjs-pkg version numbering, introduced after 7.10rc1. Ryan is away for a few more days, but the current 1.22 HEAD should be essentially the same as the `1.22.3.0` release (other than changelog updates). Can the module be bumped to HEAD now so we can start using the fixed Cabal? -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10304> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10292: Validate fails on armhf-linux
by GHC 23 Apr '15

23 Apr '15

#10292: Validate fails on armhf-linux -------------------------------------+------------------------------------- Reporter: erikd | Owner: Type: bug | Status: new Priority: normal | Milestone: 7.10.2 Component: Compiler | Version: 7.10.1 Keywords: | Operating System: Unknown/Multiple Architecture: arm | Type of failure: Building GHC Test Case: | failed Blocking: | Blocked By: Differential Revisions: | Related Tickets: -------------------------------------+------------------------------------- After apply the 'configure : LLVM and LD detection improvements' patch from #10234 validation of the ghc-7.10 branch fails with: {{{ inplace/bin/dll-split compiler/stage2/build/.depend-v-dyn.haskell \ "DynFlags" "Annotations ApiAnnotation Avail Bag BasicTypes Binary \ BooleanFormula BreakArray BufWrite Class CmdLineParser CmmType CoAxiom \ ConLike Coercion Config Constants CoreArity CoreFVs CoreSubst CoreSyn \ CoreTidy CoreUnfold CoreUtils CostCentre DataCon Demand Digraph \ DriverPhases DynFlags Encoding ErrUtils Exception ExtsCompat46 \ FamInstEnv FastFunctions FastMutInt FastString FastTypes Fingerprint \ FiniteMap ForeignCall Hooks HsBinds HsDecls HsDoc HsExpr HsImpExp \ HsLit PlaceHolder HsPat HsSyn HsTypes HsUtils HscTypes IOEnv Id \ IdInfo IfaceSyn IfaceType InstEnv Kind Lexeme ListSetOps Literal \ Maybes MkCore MkId Module MonadUtils Name NameEnv NameSet OccName \ OccurAnal OptCoercion OrdList Outputable PackageConfig Packages Pair \ Panic PatSyn PipelineMonad Platform PlatformConstants PprCore PrelNames \ PrelRules Pretty PrimOp RdrName Rules Serialized SrcLoc StaticFlags \ StringBuffer TcEvidence TcRnTypes TcType TrieMap TyCon Type TypeRep \ TysPrim TysWiredIn Unify UniqFM UniqSet UniqSupply Unique Util Var \ VarEnv VarSet Bitmap BlockId ByteCodeAsm ByteCodeInstr ByteCodeItbls \ CLabel Cmm CmmCallConv CmmExpr CmmInfo CmmMachOp CmmNode CmmUtils \ CodeGen.Platform CodeGen.Platform.ARM CodeGen.Platform.ARM64 \ CodeGen.Platform.NoRegs CodeGen.Platform.PPC CodeGen.Platform.PPC_Darwin \ CodeGen.Platform.SPARC CodeGen.Platform.X86 CodeGen.Platform.X86_64 \ FastBool Hoopl Hoopl.Dataflow InteractiveEvalTypes MkGraph PprCmm \ PprCmmDecl PprCmmExpr Reg RegClass SMRep StgCmmArgRep StgCmmClosure \ StgCmmEnv StgCmmLayout StgCmmMonad StgCmmProf StgCmmTicky StgCmmUtils \ StgSyn Stream" compiler/ghc.mk:653: recipe for target 'compiler/stage2/dll-split.stamp' failed make[1]: *** [compiler/stage2/dll-split.stamp] Segmentation fault }}} There have been a number of tickets related to `dll-split` on armhf. I have verified that the `ld.gold` linker is being invoked. The fixes introduced in #9873 also seem to be present. More investigation needed. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10292> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10297: Floating instance for Data.Fixed
by GHC 22 Apr '15

22 Apr '15

#10297: Floating instance for Data.Fixed -------------------------------------+------------------------------------- Reporter: dmcclean | Owner: Type: feature | Status: new request | Milestone: Priority: normal | Version: 7.10.1 Component: | Operating System: Unknown/Multiple libraries/base | Type of failure: None/Unknown Keywords: | Blocked By: Architecture: | Related Tickets: Unknown/Multiple | Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- I'd like to contribute a Floating instance for Data.Fixed. I'm concerned that it may be undesirable for a reason that is not occurring to me; I'd be pleased to learn of any objections. In concept it's this, although I will investigate if there is an implementation with better performance: {{{ lift :: (HasResolution a) => (Double -> Double) -> Fixed a -> Fixed a lift f = realToFrac . f . realToFrac instance (HasResolution a) => Floating (Fixed a) where pi = realToFrac pi sin = lift sin -- etc, similar lift2 function for (**), logBase }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10297> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #7672: boot file entities are sometimes invisible and are not (semantically) unified with corresponding entities in implementing module
by GHC 22 Apr '15

22 Apr '15

#7672: boot file entities are sometimes invisible and are not (semantically) unified with corresponding entities in implementing module -------------------------------------+------------------------------------- Reporter: skilpat | Owner: ezyang Type: bug | Status: new Priority: normal | Milestone: 7.12.1 Component: Compiler (Type | Version: 7.4.2 checker) | Keywords: backpack Resolution: | Architecture: x86_64 Operating System: Linux | (amd64) Type of failure: GHC rejects | Test Case: valid program | Blocking: 10336 Blocked By: | Differential Revisions: Related Tickets: | -------------------------------------+------------------------------------- Comment (by ezyang): Removing the `filterOut` does not work. (insert more info here) -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7672#comment:11> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10325: Clearify status of ImpredicativeTypes Extension
by GHC 22 Apr '15

22 Apr '15

#10325: Clearify status of ImpredicativeTypes Extension -------------------------------------+------------------------------------- Reporter: | Owner: j80JjBjVNRMajmA | Status: new Type: bug | Milestone: Priority: normal | Version: 7.10.1 Component: | Operating System: Unknown/Multiple Documentation | Type of failure: None/Unknown Keywords: | Blocked By: Architecture: | Related Tickets: Unknown/Multiple | Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- There seem to be many statements about this extension and its problems floating around in the internet. But a user of GHC will first fall into a possibly large number of traps and problems before he finds them. I think it would help, if the GHC manual [https://downloads.haskell.org/~ghc/latest/docs/html/users_guide/other- type-extensions.html#impredicative-polymorphism] and the compiler warned about this extension (instead of suggesting it!). -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10325> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10281: Type error with Rank-n-types
by GHC 22 Apr '15

22 Apr '15

#10281: Type error with Rank-n-types -------------------------------------+------------------------------------- Reporter: rhjl | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.4 (Type checker) | Operating System: Unknown/Multiple Keywords: | Type of failure: GHC rejects Architecture: | valid program Unknown/Multiple | Blocked By: Test Case: | Related Tickets: Peirce_eq_LEM.hs | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- GHC rejects the following program (which is also attached); it accepts it if the product type is replaced by tuples and the ImpredicativeTypes option is added. I am not sure if this is a bug or an expected consequence of the typing rules, which I do not know very well. In the latter case a better error message would be helpful. The error message is: {{{ 54:17: Couldn't match type ‘(Not 𝑎0 -> 𝑐0) -> (𝑎0 -> 𝑐0) -> 𝑐0’ with ‘LEM’ Expected type: (((Peirce -> LEM) -> 𝑐) ⨿ ((LEM -> Peirce) -> 𝑐)) -> 𝑐 Actual type: (((Peirce -> (Not 𝑎0 -> 𝑐0) -> (𝑎0 -> 𝑐0) -> 𝑐0) -> 𝑐) ⨿ ((LEM -> ((𝑎1 -> 𝑏0) -> 𝑎1) -> 𝑎1) -> 𝑐)) -> 𝑐 In the expression: peirce_implies_lem `and` lem_implies_peirce In an equation for ‘peirce_eq_lem’: peirce_eq_lem = peirce_implies_lem `and` lem_implies_peirce }}} This is the code: {{{#!hs {-# LANGUAGE NoImplicitPrelude #-} {-# LANGUAGE RankNTypes #-} {-# LANGUAGE TypeOperators #-} {-# LANGUAGE UnicodeSyntax #-} -- truth type True = ∀ 𝑎. 𝑎 → 𝑎 type False = ∀ 𝑎. 𝑎 id ∷ True id 𝑥 = 𝑥 (∘) ∷ ∀ 𝑎 𝑏 𝑐. (𝑏 → 𝑐) → (𝑎 → 𝑏) → 𝑎 → 𝑐 𝑓 ∘ 𝑔 = \𝑥 → 𝑓 (𝑔 𝑥) -- negation type Not 𝑎 = 𝑎 → False -- disjunction / coproduct type 𝑎 ⨿ 𝑏 = ∀ 𝑐. (𝑎 → 𝑐) → (𝑏 → 𝑐) → 𝑐 𝜄₀ ∷ ∀ 𝑎 𝑏. 𝑎 → 𝑎 ⨿ 𝑏 𝜄₀ 𝑥 = \𝑙 _ → 𝑙 𝑥 𝜄₁ ∷ ∀ 𝑎 𝑏. 𝑏 → 𝑎 ⨿ 𝑏 𝜄₁ 𝑥 = \_ 𝑟 → 𝑟 𝑥 -- conjunction / product type 𝑎 × 𝑏 = ∀ 𝑐. (𝑎 → 𝑐) ⨿ (𝑏 → 𝑐) → 𝑐 𝜋₀ ∷ ∀ 𝑎 𝑏. 𝑎 × 𝑏 → 𝑎 𝜋₀ 𝑝 = 𝑝 (𝜄₀ id) 𝜋₁ ∷ ∀ 𝑎 𝑏. 𝑎 × 𝑏 → 𝑏 𝜋₁ 𝑝 = 𝑝 (𝜄₁ id) and ∷ ∀ 𝑎 𝑏. 𝑎 → 𝑏 → 𝑎 × 𝑏 𝑥 `and` 𝑦 = \𝑐 → 𝑐 (\𝑙 → 𝑙 𝑥) (\𝑟 → 𝑟 𝑦) -- equivalence type 𝑎 ↔ 𝑏 = (𝑎 → 𝑏) × (𝑏 → 𝑎) -- peirce ↔ lem type Peirce = ∀ 𝑎 𝑏. ((𝑎 → 𝑏) → 𝑎) → 𝑎 type LEM = ∀ 𝑎. (Not 𝑎) ⨿ 𝑎 peirce_eq_lem ∷ Peirce ↔ LEM peirce_eq_lem = peirce_implies_lem `and` lem_implies_peirce peirce_implies_lem ∷ Peirce → LEM peirce_implies_lem peirce = peirce (\𝑘 → 𝜄₀ (𝑘 ∘ 𝜄₁)) lem_implies_peirce ∷ LEM → Peirce lem_implies_peirce lem = \𝑓 → lem (\𝑥 → 𝑓 𝑥) id }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10281> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10182: lookupIfaceGlobal crash with SOURCE import
by GHC 22 Apr '15

22 Apr '15

#10182: lookupIfaceGlobal crash with SOURCE import -------------------------------------+------------------------------------- Reporter: simonpj | Owner: Type: bug | Status: new Priority: normal | Milestone: 7.12.1 Component: Compiler | Version: 7.8.4 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Blocked By: Test Case: | Related Tickets: Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- Try this (in `testsuite/tests/stranal/should_compile`) {{{ bash$ ghc -c T8743.hs-boot bash$ ghc -c T8743.hs ghc: panic! (the 'impossible' happened) (GHC version 7.8.2 for x86_64-unknown-linux): tcIfaceGlobal (local): not found: main:T8743.$fxToRowMaybe{v r2J} [(r2L, Class ‘main:T8743.ToRow{tc r2L}’), (r2M, Data constructor ‘main:T8743.D:ToRow{d r2M}’), (r2P, Identifier ‘main:T8743.D:ToRow{v r2P}’), (roB, Identifier ‘main:T8743.toRow{v roB}’), (rqT, Coercion axiom ‘main:T8743.NTCo:ToRow{tc rqT}’)] }}} Something clearly wrong here. It think this happens with prettty much any version of GHC. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10182> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10341: hs-boot files can have bogus declarations if they're not exported
by GHC 22 Apr '15

22 Apr '15

#10341: hs-boot files can have bogus declarations if they're not exported -------------------------------------+------------------------------------- Reporter: ezyang | Owner: Type: bug | Status: new Priority: low | Milestone: Component: Compiler | Version: 7.11 (Type checker) | Operating System: Unknown/Multiple Keywords: | Type of failure: GHC accepts Architecture: | invalid program Unknown/Multiple | Blocked By: Test Case: | Related Tickets: Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- Consider: {{{ -- A.hs-boot module A(foo) where data A = AC { bar :: Int } | CC -- B.hs module B where import {-# SOURCE #-} A -- A.hs module A(foo) where import B data A = AC { foo :: Int } | BC }}} GHC won't complain that `A` is incompatibly defined, since it's not exported. Seems relatively harmless though. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10341> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8743: The impossible happened : Prelude.(!!): index too large
by GHC 22 Apr '15

22 Apr '15

#8743: The impossible happened : Prelude.(!!): index too large ----------------------------------+--------------------------------------- Reporter: erikd | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.1-rc1 Keywords: | Operating System: Unknown/Multiple Architecture: x86_64 (amd64) | Type of failure: Compile-time crash Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ----------------------------------+--------------------------------------- Running ghc git HEAD (reports it's version as 7.9.20140206) and when cabal installing postgresql-simple I get: {{{ ghc: panic! (the 'impossible' happened) (GHC version 7.9.20140206 for x86_64-unknown-linux): Prelude.(!!): index too large Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug cabal: Error: some packages failed to install: postgresql-simple-0.4.0.2 failed during the building phase. The exception was: }}} postgresql-simple-0.4.0.2 installs fine with 7.6.3. I'm going to compile 7.8-rc1 and see if the same problem exists there. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8743> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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