January 2014 - ghc-tickets

[GHC] #8124: Possible leaks when using foreign export.
by GHC 17 Mar '14

17 Mar '14

#8124: Possible leaks when using foreign export. ------------------------------+-------------------------------------------- Reporter: augustss | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Runtime | Version: 7.6.3 System | Operating System: Unknown/Multiple Keywords: | Type of failure: Runtime performance bug Architecture: | Test Case: Unknown/Multiple | Blocking: Difficulty: Unknown | Blocked By: | Related Tickets: | ------------------------------+-------------------------------------------- When a Haskell function exported with foreign export is called from outside Haskell a new Task may be allocated for it. There will be one Task allocated for each OS thread calling into Haskell (this happens in rts_lock()). This Task is, by design, never deallocated. This works fine with a small number of threads, but if the external caller generates a lot of threads that die the Haskell RTS will just get more and more Task objects that are never freed. The Task also contains a condition variable and a mutex, which incurs a HANDLE leak on Windows. I don't see an elegant fix to this, but the attached code remembers the OS thread for "incall" Task, and every so often (every 100 Tasks created) if will scan the Tasks looking for ones where the OS thread is dead, and remove these. The fix only works on Windows, I'm afraid. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8124> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8718: Add role annotations to base
by GHC 14 Mar '14

14 Mar '14

#8718: Add role annotations to base -------------------------------------------+------------------------------- Reporter: nomeata | Owner: Type: task | Status: new Priority: high | Milestone: 7.8.1 Component: libraries/base | Version: 7.6.3 Keywords: | Operating System: Architecture: Unknown/Multiple | Unknown/Multiple Difficulty: Easy (less than 1 hour) | Type of failure: Blocked By: | None/Unknown Related Tickets: | Test Case: | Blocking: -------------------------------------------+------------------------------- With roles and Coercible in GHC, we ought to add role annotations to base and other libraries. We have them for `Ptr` and `FunPtr`; I guess we need them for * `Map` (first parameter) * `Set` * `Vector` (or rather its primitive building block) What else? -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8718> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8678: Derivin `Functor` complains about existential type
by GHC 07 Mar '14

07 Mar '14

#8678: Derivin `Functor` complains about existential type ------------------------------------+------------------------------------- Reporter: heisenbug | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.7 Keywords: | Operating System: Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+------------------------------------- When deriving a functor with !DataKinds enabled {{{ {-# LANGUAGE DataKinds, DeriveFunctor, FlexibleInstances, GADTs, KindSignatures, StandaloneDeriving #-} data {- kind -} Nat = Z | S Nat data NonStandard :: Nat -> * -> * where Standard :: a -> NonStandard (S n) a Non :: NonStandard n a -> a -> NonStandard (S n) a deriving instance Show a => Show (NonStandard n a) deriving instance Functor (NonStandard n) }}} I get following error message {{{ NonStandard.hs:10:1: Can't make a derived instance of ‛Functor (NonStandard n)’: Constructor ‛Standard’ must not have existential arguments In the stand-alone deriving instance for ‛Functor (NonStandard n)’ }}} But the `Standard` constructor is not at all existential in the last type argument! -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8678> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8254: confusing comment on allocate()
by GHC 27 Feb '14

27 Feb '14

#8254: confusing comment on allocate() ------------------------------------+-------------------------------------- Reporter: rwbarton | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Runtime System | Version: 7.7 Keywords: | Operating System: Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: Documentation bug Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+-------------------------------------- {{{ /* ----------------------------------------------------------------------------- allocate() This allocates memory in the current thread - it is intended for use primarily from STG-land where we have a Capability. It is better than allocate() because it doesn't require taking the sm_mutex lock in the common case. Memory is allocated directly from the nursery if possible (but not from the current nursery block, so as not to interfere with Hp/HpLim). -------------------------------------------------------------------------- */ }}} Not sure what, if anything, `allocate()` is better than, but it's not `allocate()`. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8254> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8512: Add flag like '-xc' that only reports uncaught exceptions
by GHC 21 Feb '14

21 Feb '14

#8512: Add flag like '-xc' that only reports uncaught exceptions ------------------------------------+------------------------------------- Reporter: blitzcode | Owner: simonmar Type: feature request | Status: new Priority: normal | Milestone: Component: Runtime System | Version: 7.6.3 Keywords: | Operating System: Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+------------------------------------- The -xc RTS flag reports the stack trace of all exceptions. This can be very noisy when, for instance, certain http or parsing libraries are used that throw many exceptions, often handled fully internal, during their normal operation. Having multiple threads makes it even noisier. I'd think having a flag like -xc that only reports uncaught exceptions would be useful. It seems the GHCi debugger has a flag to only stop on uncaught exceptions, maybe this could be made available as an RTS option? -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8512> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8719: clarify prefetch release notes + remove some deadcode
by GHC 20 Feb '14

20 Feb '14

#8719: clarify prefetch release notes + remove some deadcode ------------------------------------+------------------------------------- Reporter: carter | Owner: Type: bug | Status: new Priority: normal | Milestone: 7.8.1 Component: Compiler | Version: 7.8.1-rc1 Keywords: | Operating System: Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+------------------------------------- https://github.com/cartazio/ghc/compare/ghc:ghc-7.8...amend-prefetch- release-notes noticed some deadcode in the -fvia-c related to prefetch, removes that too i have those two as separate commits so they can be handled more easily -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8719> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8705: Type inference regression with local dictionaries
by GHC 19 Feb '14

19 Feb '14

#8705: Type inference regression with local dictionaries -------------------------------------------+------------------------------- Reporter: goldfire | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type checker) | Version: 7.7 Keywords: | Operating System: Architecture: Unknown/Multiple | Unknown/Multiple Difficulty: Unknown | Type of failure: Blocked By: | None/Unknown Related Tickets: | Test Case: | Blocking: -------------------------------------------+------------------------------- Consider this code: {{{ {-# LANGUAGE ScopedTypeVariables, TypeOperators, DataKinds, MultiParamTypeClasses, GADTs, ConstraintKinds #-} import Data.Singletons.Prelude import GHC.Exts data Dict c where Dict :: c => Dict c -- A less-than-or-equal relation among naturals class a :<=: b sLeq :: Sing n -> Sing n2 -> Dict (n :<=: n2) sLeq = undefined insert_ascending :: forall n lst n1. (lst ~ '[n1]) => Proxy n1 -> Sing n -> SList lst -> Dict (n :<=: n1) insert_ascending _ n lst = case lst of -- If lst has one element... SCons h _ -> case sLeq n h of -- then check if n is <= h Dict -> Dict -- if so, we're done }}} (adapted from [https://github.com/goldfirere/singletons/blob/master/Test/InsertionSortImp.… this file]) GHC 7.6.3 compiles without incident. When I run HEAD (with `-fprint- explicit-kinds`), I get {{{ Ins.hs:25:17: Could not deduce (n :<=: n1) arising from a use of ‛Dict’ from the context ((~) [*] lst ((':) * n1 ('[] *))) bound by the type signature for insert_ascending :: (~) [*] lst ((':) * n1 ('[] *)) => Proxy * n1 -> Sing * n -> SList * lst -> Dict (n :<=: n1) at Ins.hs:(20,21)-(21,70) or from ((~) [*] lst ((':) * n0 n2)) bound by a pattern with constructor SCons :: forall (a0 :: BOX) (z0 :: [a0]) (n0 :: a0) (n1 :: [a0]). (~) [a0] z0 ((':) a0 n0 n1) => Sing a0 n0 -> Sing [a0] n1 -> Sing [a0] z0, in a case alternative at Ins.hs:24:7-15 or from (n :<=: n0) bound by a pattern with constructor Dict :: forall (c :: Constraint). (c) => Dict c, in a case alternative at Ins.hs:25:9-12 Possible fix: add (n :<=: n1) to the context of the data constructor ‛Dict’ or the data constructor ‛SCons’ or the type signature for insert_ascending :: (~) [*] lst ((':) * n1 ('[] *)) => Proxy * n1 -> Sing * n -> SList * lst -> Dict (n :<=: n1) In the expression: Dict In a case alternative: Dict -> Dict In the expression: case sLeq n h of { Dict -> Dict } }}} If you stare at the type error long enough, you will see that GHC should be able to type-check this. The test case requires singletons-0.9.x, but is already much reduced. Interestingly, if all the "givens" are put in the top-level type signature, GHC does its job well. It seems that the act of unpacking the dictionaries is causing the problem. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8705> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8301: error BaseReg must be in a register for THREADED_RTS
by GHC 17 Feb '14

17 Feb '14

#8301: error BaseReg must be in a register for THREADED_RTS -----------------------------+---------------------------------------- Reporter: erikd | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.7 Keywords: | Operating System: Linux Architecture: powerpc64 | Type of failure: Building GHC failed Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | -----------------------------+---------------------------------------- Compiling git HEAD on powerpc64-linux. This was working as recently as two weeks ago. Now getting: {{{ "inplace/bin/ghc-stage1" -hisuf hi -osuf o -hcsuf hc -static -H32m -O -Werror -Wall -H64m -O0 -package-name ghc-7.7.20130914 -hide-all-packages -i -icompiler/basicTypes -icompiler/cmm -icompiler/codeGen -icompiler/coreSyn -icompiler/deSugar -icompiler/ghci -icompiler/hsSyn -icompiler/iface -icompiler/llvmGen -icompiler/main -icompiler/nativeGen -icompiler/parser -icompiler/prelude -icompiler/profiling -icompiler/rename -icompiler/simplCore -icompiler/simplStg -icompiler/specialise -icompiler/stgSyn -icompiler/stranal -icompiler/typecheck -icompiler/types -icompiler/utils -icompiler/vectorise -icompiler/stage2/build -icompiler/stage2/build/autogen -Icompiler/stage2/build -Icompiler/stage2/build/autogen -Icompiler/. -Icompiler/parser -Icompiler/utils -Icompiler/stage2 -optP-include -optPcompiler/stage2/build/autogen/cabal_macros.h -package Cabal-1.18.1 -package array-0.4.0.2 -package base-4.7.0.0 -package bin-package-db-0.0.0.0 -package bytestring-0.10.3.0 -package containers-0.5.3.1 -package directory-1.2.0.1 -package filepath-1.3.0.2 -package hoopl-3.10.0.0 -package hpc-0.6.0.1 -package process-1.2.0.0 -package time-1.4.1 -package transformers-0.3.0.0 -package unix-2.7.0.0 -Wall -fno-warn-name-shadowing -XHaskell98 -XCPP -XMagicHash -XUnboxedTuples -XPatternGuards -XForeignFunctionInterface -XEmptyDataDecls -XTypeSynonymInstances -XMultiParamTypeClasses -XFlexibleInstances -XRankNTypes -XScopedTypeVariables -XDeriveDataTypeable -XBangPatterns -XNondecreasingIndentation -DNO_REGS -optc-DTHREADED_RTS -DSTAGE=2 -O2 -fwarn-tabs -fno-warn-amp -O -dcore-lint -no-user-package-db -rtsopts -odir compiler/stage2/build -hidir compiler/stage2/build -stubdir compiler/stage2/build -c compiler/utils/Platform.hs -o compiler/stage2/build/Platform.o In file included from /home/erikd/PPC64/ghc-ppc64/includes/Stg.h:232:0: 0, from /tmp/ghc10950_0/ghc10950_2.hc:3: /home/erikd/PPC64/ghc-ppc64/includes/stg/Regs.h:359:2: error: #error BaseReg must be in a register for THREADED_RTS }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8301> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8365: stage2 build fails on Solaris (SmartOS)
by GHC 17 Feb '14

17 Feb '14

#8365: stage2 build fails on Solaris (SmartOS) ----------------------------------+---------------------------------------- Reporter: oddsignals | Owner: Type: bug | Status: new Priority: high | Milestone: 7.8.1 Component: Runtime System | Version: 7.7 Keywords: | Operating System: Solaris Architecture: x86 | Type of failure: Building GHC failed Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ----------------------------------+---------------------------------------- I'm getting some missing symbols building on 32-bit SmartOS. 'quick' flavour build, DYNAMIC_BY_DEFAULT = NO, DYNAMIC_GHC_PROGRAMS = NO. {{{ $ uname -a SunOS pkgx86 5.11 joyent_20130919T215407Z i86pc i386 i86pc Solaris }}} {{{ "inplace/bin/ghc-stage1" -o ghc/stage2/build/tmp/ghc-stage2 -hisuf hi -osuf o -hcsuf hc -static -H64m -O0 -fasm -hide-all-packages -i -ighc/. -ighc/stage2/build -ighc/stage2/build/autogen -Ighc/stage2/build -Ighc/stage2/build/autogen -optP-DGHCI -optP-include -optPghc/stage2/build/autogen/cabal_macros.h -package array-0.4.0.2 -package base-4.7.0.0 -package bytestring-0.10.3.0 -package directory-1.2.0.1 -package filepath-1.3.0.2 -package ghc-7.7.20130926 -package haskeline-0.7.0.4 -package process-1.2.0.0 -package transformers-0.3.0.0 -package unix-2.7.0.0 -Wall -fno-warn-name-shadowing -XHaskell98 -XCPP -XPatternGuards -XNondecreasingIndentation -XForeignFunctionInterface -XUnboxedTuples -XFlexibleInstances -XMagicHash -O0 -fasm -threaded -no-user-package-db -rtsopts -odir ghc/stage2/build -hidir ghc/stage2/build -stubdir ghc/stage2/build ghc/stage2/build/Main.o ghc/stage2/build/InteractiveUI.o ghc/stage2/build/GhciMonad.o ghc/stage2/build/GhciTags.o ghc/stage2/build/hschooks.o <no location info>: Warning: Couldn't figure out linker information! Make sure you're using GNU ld, GNU gold or the built in OS X linker, etc. Undefined first referenced symbol in file base_GHCziConcziIO_ensureIOManagerIsRunning_closure /opt/src/ghc/rts/dist/build/libHSrts_thr.a(RtsStartup.thr_o) base_GHCziConcziIO_ioManagerCapabilitiesChanged_closure /opt/src/ghc/rts/dist/build/libHSrts_thr.a(RtsStartup.thr_o) base_GHCziPack_unpackCString_closure /opt/src/ghc/rts/dist/build/libHSrts_thr.a(RtsAPI.thr_o) ld: fatal: symbol referencing errors. No output written to ghc/stage2/build/tmp/ghc-stage2 collect2: error: ld returned 1 exit status make[1]: *** [ghc/stage2/build/tmp/ghc-stage2] Error 1 make: *** [all] Error 2 }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8365> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8722: powerpc64: error Cannot find a way to declare the thread-local gc variable
by GHC 17 Feb '14

17 Feb '14

#8722: powerpc64: error Cannot find a way to declare the thread-local gc variable -----------------------------+---------------------------------------- Reporter: trommler | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.1-rc1 Keywords: | Operating System: Linux Architecture: powerpc64 | Type of failure: Building GHC failed Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | -----------------------------+---------------------------------------- Building 7.8.RC1 on powerpc64 fails with: {{{ [ 2883s] In file included from rts/sm/GCUtils.h:19:0, [ 2883s] from rts/sm/Scav.c:20: [ 2883s] rts/sm/GCTDecl.h:139:2: error: #error Cannot find a way to declare the thread-local gc variable! [ 2883s] #error Cannot find a way to declare the thread-local gc variable! [ 2883s] ^ [ 2883s] rts/ghc.mk:512: recipe for target 'rts/dist/build/.depend-v-l -debug-thr-thr_debug-thr_l.c_asm' failed [ 2883s] make[1]: *** [rts/dist/build/.depend-v-l-debug-thr-thr_debug- thr_l.c_asm] Error 1 }}} The build is unregisterized (default) and does not use dynamic linking (DYNAMIC_GHC_PROGRAMS=NO and DYNAMIC-BY_DEFAULT=NO). It might be related to #8301. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8722> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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