October 2015 - ghc-tickets

[GHC] #10921: weird "optimisation levels" in man page
by GHC 16 Jan '16

16 Jan '16

#10921: weird "optimisation levels" in man page -------------------------------------+------------------------------------- Reporter: osa1 | Owner: Type: task | Status: new Priority: lowest | Milestone: Component: Documentation | Version: 7.10.2 Keywords: manpage, | Operating System: Unknown/Multiple newcomer | Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | -------------------------------------+------------------------------------- Man page shows this: {{{ Optimisation levels -O0 -O -O or -O1 -O0 -O2 -O0 -Odph }}} This looks very weird: - Why -O and -O0 listed twice? - That `or` looks weird, how do I read that? Apparently the man page is auto-generated from the user manual(thanks @int-e), and while doing that "reverse" column is also included. We should probably either ignore "reverse" column while parsing the user manual parts or somehow re-format generated man page lines. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10921> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8114: GHC panic when building `thyme`
by GHC 16 Jan '16

16 Jan '16

#8114: GHC panic when building `thyme` -----------------------------------+--------------------------------------- Reporter: Ptharien's | Owner: Flame | Status: new Type: bug | Milestone: Priority: normal | Version: 7.6.3 Component: Compiler | Operating System: MacOS X Keywords: | Type of failure: Compile-time crash Architecture: x86_64 (amd64) | Test Case: Difficulty: Unknown | Blocking: Blocked By: | Related Tickets: | -----------------------------------+--------------------------------------- While attempting to build `thyme` from Hackage with core, stg, and cmm linting and -O2 enabled, GHC crashed with an internal panic. See attached terminal log. {{{ rrdhcp-10-32-234-247:thyme-0.2.4.1 Alexander$ ghc --version The Glorious Glasgow Haskell Compilation System, version 7.6.3 rrdhcp-10-32-234-247:thyme-0.2.4.1 Alexander$ cabal --version cabal-install version 1.16.0.2 using version 1.16.0 of the Cabal library rrdhcp-10-32-234-247:thyme-0.2.4.1 Alexander$ which ghc /usr/local/bin/ghc rrdhcp-10-32-234-247:thyme-0.2.4.1 Alexander$ which cabal /Users/Alexander/Library/Haskell/bin/cabal }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8114> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10872: More informative assertion for non-unique TH names
by GHC 16 Jan '16

16 Jan '16

#10872: More informative assertion for non-unique TH names -------------------------------------+------------------------------------- Reporter: jstolarek | Owner: Type: task | Status: new Priority: low | Milestone: Component: Compiler | Version: 7.11 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Revisions: | -------------------------------------+------------------------------------- Let's say that by accident I have duplicated uniques of Template Haskell built-in identifiers defined in `THNames` module: {{{#!hs returnQIdKey = mkPreludeMiscIdUnique 200 bindQIdKey = mkPreludeMiscIdUnique 200 }}} If I have a debugging build (`-DDEBUG`) and start a GHCi session it crashes immediately with a very uninformative error message: {{{ GHCi, version 7.11.20150903: http://www.haskell.org/ghc/ :? for help <interactive>:1:1: error: Bad interface file: /dane/projekty/ghc/build/libraries/base/dist- install/build/Prelude.hi ghc-stage2: panic! (the 'impossible' happened) (GHC version 7.11.20150903 for x86_64-unknown-linux): ASSERT failed! <<details unavailable>> Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} I have no idea where this assertion comes from as it gives absolutely no clue as to what caused the problem. During ICFP this costed me and Richard a total of around 6 man-hours. We should replace that assertion with something more meaningful. One thing we could do is add an assertion to the definition of `THNames.templateHaskellNames` that makes sure that `length templateHaskellNames == length (nub templateHaskellNames)`. That by itself is very simple but the problem is that the uninformative assertion given above still kicks in first. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10872> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11015: Add note describing unit ids, unit keys, package ids, and package keys,
by GHC 15 Jan '16

15 Jan '16

#11015: Add note describing unit ids, unit keys, package ids, and package keys, -------------------------------------+------------------------------------- Reporter: bgamari | Owner: ezyang 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 | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- It would be great if there were a nice comprehensive Note (perhaps in `Module.hs`) describing the various identifiers which we have for modules, packages, units, etc. These might include, * `Package` * `PkgName` * `PkgKey` * `PkgId` * `UnitId` * `UnitKey` * Component? After writing this I found [[Commentary/Packages/Concepts]] but it would be great if this information found its way into a nice, central Note. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11015> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8613: simplifier ticks exhausted
by GHC 13 Jan '16

13 Jan '16

#8613: simplifier ticks exhausted ----------------------------------+---------------------------- Reporter: guest | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.6.3 Keywords: | Operating System: MacOS X Architecture: x86_64 (amd64) | Type of failure: Other Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ----------------------------------+---------------------------- (Sent by chrisreade(a)mac.com ) Compiler giving up with simplifier ticks exhausted. Large amount of simplification may be going on to cause this. The problem goes away when using -fsimpl-tick-factor=1000 and the code runs. This is the session output without the flag (asking to have bug reported): chris$ ghc -O2 -rtsopts RedBlackStencilOpt.hs -v Glasgow Haskell Compiler, Version 7.6.3, stage 2 booted by GHC version 7.4.2 Using binary package database: /Library/Frameworks/GHC.framework/Versions/7.6.3-x86_64/usr/lib/ghc-7.6.3/package.conf.d/package.cache Using binary package database: /Users/chris/.ghc/x86_64-darwin-7.6.3/package.conf.d/package.cache hiding package binary-0.5.1.1 to avoid conflict with later version binary-0.6.4.0 hiding package Cabal-1.16.0 to avoid conflict with later version Cabal-1.18.1.1 wired-in package ghc-prim mapped to ghc- prim-0.3.0.0-d5221a8c8a269b66ab9a07bdc23317dd wired-in package integer-gmp mapped to integer- gmp-0.5.0.0-2f15426f5b53fe4c6490832f9b20d8d7 wired-in package base mapped to base-4.6.0.1-6c351d70a24d3e96f315cba68f3acf57 wired-in package rts mapped to builtin_rts wired-in package template-haskell mapped to template- haskell-2.8.0.0-c2c1b21dbbb37ace4b7dc26c966ec664 wired-in package dph-seq not found. wired-in package dph-par not found. Hsc static flags: -static *** Chasing dependencies: Chasing modules from: *RedBlackStencilOpt.hs Stable obj: [] Stable BCO: [] Ready for upsweep [NONREC ModSummary { ms_hs_date = 2013-12-13 13:12:37 UTC ms_mod = main:RedBlackStencilOpt, ms_textual_imps = [import (implicit) Prelude, import Data.Array.Repa.Stencil.Dim2 as A, import Data.Array.Repa.Stencil as A, import Data.Array.Repa as A] ms_srcimps = [] }] *** Deleting temp files: Deleting: compile: input file RedBlackStencilOpt.hs Created temporary directory: /var/folders/dz/m1mks1yn1bsft72zgh105sw40000gn/T/ghc93155_0 *** Checking old interface for main:RedBlackStencilOpt: [1 of 1] Compiling RedBlackStencilOpt ( RedBlackStencilOpt.hs, RedBlackStencilOpt.o ) *** Parser: *** Renamer/typechecker: *** Simplify: *** CorePrep: *** ByteCodeGen: Loading package ghc-prim ... linking ... done. Loading package integer-gmp ... linking ... done. *** gcc: '/usr/bin/gcc' '-m64' '-fno-stack-protector' '-m64' '-L/Library/Frameworks/GHC.framework/Versions/7.6.3-x86_64/usr/lib/ghc-7.6.3/base-4.6.0.1' '--print-file-name' 'libiconv.dylib' Loading package base ... linking ... done. Loading package pretty-1.1.1.0 ... linking ... done. Loading package array-0.4.0.1 ... linking ... done. Loading package deepseq-1.3.0.1 ... linking ... done. Loading package containers-0.5.0.0 ... linking ... done. Loading package old-locale-1.0.0.5 ... linking ... done. Loading package time-1.4.0.1 ... linking ... done. Loading package random-1.0.1.1 ... linking ... done. Loading package template-haskell ... linking ... done. Loading package QuickCheck-2.6 ... linking ... done. Loading package bytestring-0.10.0.2 ... linking ... done. Loading package primitive-0.5.0.1 ... linking ... done. Loading package vector-0.10.0.1 ... linking ... done. Loading package repa-3.2.3.3 ... linking ... done. *** Simplify: *** CorePrep: *** ByteCodeGen: *** Desugar: Result size of Desugar (after optimization) = {terms: 900, types: 1,810, coercions: 340} *** Simplifier: Result size of Simplifier iteration=1 = {terms: 834, types: 1,757, coercions: 567} Result size of Simplifier iteration=2 = {terms: 830, types: 1,721, coercions: 567} Result size of Simplifier = {terms: 830, types: 1,721, coercions: 567} *** Specialise: Result size of Specialise = {terms: 830, types: 1,721, coercions: 567} *** Float out(FOS {Lam = Just 0, Consts = True, PAPs = False}): Result size of Float out(FOS {Lam = Just 0, Consts = True, PAPs = False}) = {terms: 993, types: 2,131, coercions: 567} *** Float inwards: Result size of Float inwards = {terms: 993, types: 2,131, coercions: 567} *** Simplifier: *** Deleting temp files: Deleting: /var/folders/dz/m1mks1yn1bsft72zgh105sw40000gn/T/ghc93155_0/ghc93155_0.s Warning: deleting non-existent /var/folders/dz/m1mks1yn1bsft72zgh105sw40000gn/T/ghc93155_0/ghc93155_0.s *** Deleting temp dirs: Deleting: /var/folders/dz/m1mks1yn1bsft72zgh105sw40000gn/T/ghc93155_0 ghc: panic! (the 'impossible' happened) (GHC version 7.6.3 for x86_64-apple-darwin): Simplifier ticks exhausted When trying RuleFired Class op szipWith To increase the limit, use -fsimpl-tick-factor=N (default 100) If you need to do this, let GHC HQ know, and what factor you needed To see detailed counts use -ddump-simpl-stats Total ticks: 60402 Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8613> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10697: Change template-haskell API to allow NOUNPACK, lazy annotations
by GHC 13 Jan '16

13 Jan '16

#10697: Change template-haskell API to allow NOUNPACK, lazy annotations -------------------------------------+------------------------------------- Reporter: | Owner: RyanGlScott | Type: feature | Status: new request | Priority: normal | Milestone: Component: Template | Version: 7.10.1 Haskell | Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: #8347 Differential Revisions: | -------------------------------------+------------------------------------- Currently, the {{{template-haskell}}} API is lagging behind what is possible with GHC's strictness annotations in data types, especially since the advent of {{{StrictData}}}. Currently, {{{template-haskell}}} has {{{Strict}}}: {{{#!hs data Strict = IsStrict | NotStrict | Unpacked }}} But it appears that there are actually nine different combinations of packedness and strictness annotations: {{{#!hs data A = A Int -- No unpackedness, no strictness data A = A !Int -- No unpackedness, strict data A = A ~Int -- No unpackedness, lazy data A = A {-# NOUNPACK #-} A Int -- NOUNPACK, no strictness data A = A {-# NOUNPACK #-} A !Int -- NOUNPACK, strict data A = A {-# NOUNPACK #-} A ~Int -- NOUNPACK, lazy data A = A {-# UNPACK #-} A Int -- UNPACK, no strictness data A = A {-# UNPACK #-} A !Int -- UNPACK, strict data A = A {-# UNPACK #-} A ~Int -- UNPACK, lazy }}} It seems like the most consistent thing to do would be change {{{Strict}}} and add {{{Unpack}}} to the {{{template-haskell}}} API: {{{#!hs data Strict = IsStrict | NotStrict | IsLazy data Unpack = Unpack | NoUnpack | NotUnpacked type UnpackStrictType = (Unpack, Strict, Type) type VarUnpackStrictType = (Name, Unpack, Strict, Type) }}} And so on. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10697> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10070: Cross compiling from Linux to Windows with mising Win32 library
by GHC 13 Jan '16

13 Jan '16

#10070: Cross compiling from Linux to Windows with mising Win32 library -------------------------------------+------------------------------------- Reporter: erikd | Owner: erikd Type: bug | Status: new Priority: normal | Milestone: 7.12.1 Component: Build | Version: 7.11 System | Operating System: Unknown/Multiple Keywords: cross- | Type of failure: Building GHC compiling | failed Architecture: | Blocked By: Unknown/Multiple | Related Tickets: Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- After applying the proposed patch from #9524, building a Linux to Windows cross-compiler terminates with: {{{ Configuring time-1.5.0.1... ghc-cabal: At least the following dependencies are missing: Win32 -any }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10070> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10864: arm: strange closure type 64008 from cabal-install
by GHC 13 Jan '16

13 Jan '16

#10864: arm: strange closure type 64008 from cabal-install ------------------------------------+---------------------------------- Reporter: muhmuhten | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.2 Keywords: | Operating System: Linux Architecture: arm | Type of failure: Runtime crash Test Case: | Blocked By: Blocking: | Related Tickets: Differential Revisions: | ------------------------------------+---------------------------------- This is occurring on fedora 22 with ghc and cabal-install directly from the repos; I haven't checked whether the bug is actually downstream. {{{ # dnf install -y cabal-install $ cabal sandbox init cabal: internal error: evacuate(static): strange closure type 65200 (GHC version 7.8.4 for arm_unknown_linux) Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug Aborted (core dumped) $ cabal update Downloading the latest package list from hackage.haskell.org cabal: internal error: evacuate(static): strange closure type 64008 (GHC version 7.8.4 for arm_unknown_linux) Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug Aborted (core dumped) }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10864> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9048: armel: evacuate(static): strange closure type 0
by GHC 13 Jan '16

13 Jan '16

#9048: armel: evacuate(static): strange closure type 0 ------------------------------------+------------------------------------- Reporter: nomeata | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.2 Keywords: | Operating System: Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+------------------------------------- I guess I need to document the build failures here, instead of just mentioning them on the mailing list: Building 7.8 on armel on Debian fails with {{{ chmod +x inplace/bin/runghc inplace/bin/dll-split compiler/stage2/build/.depend-v-p-dyn.haskell "DynFlags" "Annotations Avail Bag BasicTypes BinIface Binary Bitmap BlockId BooleanFormula BreakArray BufWrite BuildTyCl ByteCodeAsm ByteCodeInstr ByteCodeItbls CLabel Class CmdLineParser Cmm CmmCallConv CmmExpr CmmInfo CmmMachOp CmmNode CmmType CmmUtils CoAxiom ConLike CodeGen.Platform CodeGen.Platform.ARM CodeGen.Platform.NoRegs CodeGen.Platform.PPC CodeGen.Platform.PPC_Darwin CodeGen.Platform.SPARC CodeGen.Platform.X86 CodeGen.Platform.X86_64 Coercion Config Constants CoreArity CoreFVs CoreLint CoreSubst CoreSyn CoreTidy CoreUnfold CoreUtils CostCentre DataCon Demand Digraph DriverPhases DsMonad DynFlags Encoding ErrUtils Exception ExtsCompat46 FamInstEnv FastBool FastFunctions FastMutInt FastString FastTypes Finder Fingerprint FiniteMap ForeignCall Hooks Hoopl Hoopl.Dataflow HsBinds HsDecls HsDoc HsExpr HsImpExp HsLit HsPat HsSyn HsTypes HsUtils HscTypes IOEnv Id IdInfo IfaceEnv IfaceSyn IfaceType InstEnv InteractiveEvalTypes Kind ListSetOps Literal LoadIface Maybes MkCore MkGraph MkId Module MonadUtils Name NameEnv NameSet OccName OccurAnal OptCoercion OrdList Outputable PackageConfig Packages Pair Panic PatSyn PipelineMonad Platform PlatformConstants PprCmm PprCmmDecl PprCmmExpr PprCore PrelInfo PrelNames PrelRules Pretty PrimOp RdrName Reg RegClass Rules SMRep Serialized SrcLoc StaticFlags StgCmmArgRep StgCmmClosure StgCmmEnv StgCmmLayout StgCmmMonad StgCmmProf StgCmmTicky StgCmmUtils StgSyn Stream StringBuffer TcEvidence TcIface TcRnMonad TcRnTypes TcType TcTypeNats TrieMap TyCon Type TypeRep TysPrim TysWiredIn Unify UniqFM UniqSet UniqSupply Unique Util Var VarEnv VarSet" dll-split: internal error: evacuate(static): strange closure type 0 (GHC version 7.8.2 for arm_unknown_linux) Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug make[2]: *** [compiler/stage2/dll-split.stamp] Aborted make[2]: *** Waiting for unfinished jobs.... make[1]: *** [all] Error 2 }}} Unfortunately, I’m no expert in strange architectures, so I need help from all you arm-lovers out there... Can someone, for starters, confirm this on an arm machine, or is this Debian specific somehow? (Hardening flags have been disabled.) -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9048> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10969: Arm: Investigate Thumb2/Arm interworking
by GHC 13 Jan '16

13 Jan '16

#10969: Arm: Investigate Thumb2/Arm interworking -------------------------------------+------------------------------------- Reporter: erikd | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.11 (CodeGen) | Keywords: arm, thumb | Operating System: Unknown/Multiple Architecture: arm | Type of failure: None/Unknown Test Case: | Blocked By: Blocking: | Related Tickets: #10375 Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- Arm (32 bit) has two commonly used instruction sets; Thumb2 and Arm. The former is encoded in two bytes per instruction and the latter in four bytes. The CPU also has a bit in the flags register specifyng which code execution mode the CPU is currently in. The important thing to note is that executing Arm code when in Thumb2 mode (or vice versa) will sooner or later result in an illegal insruction or segfault. During debugging of #10375, I found that Haskell code compiled via the LLVM backend was generating Arm instructions, while C code compiled via GCC was generating Thumb2 code. When object code from these two paths are linked by the system linker everything is fine because the system linker knows how to link Thumb code to Arm code to produce a valid binary. The problem in #10375 was that in GHCi, the runtime linker was loading object files without the correct fixups between Thumb2 and Arm so that Thumb2 code in the `StgRun` function was jumping correctly into Arm code in the loaded object and returning to the Thumb2 code in `StgRun` while still in Arm execution mode and then crashing. In commit [changeset:"933adc0f31164cb651d11ecfcfe612ac429f714f/ghc" 933adc0f/ghc] I fixed GHCi for Arm by forcing GHC to generate only Arm code. As discussed in the associated Phab:D1323 it would be nice to investigate this further to see if its possible to make GHC generate Thumb2 code (which potentially has some performance benefits since it encodes all instructions in two bytes) and/or fix Thumb2/Arm interop. However, that interop may not be possible. In one of the comments in the Phab:D1323, @bgamari said: > That being said, I don't think we'll ever be able to support linking of Thumb Haskell code with ARM Haskell code. The reason for this is that interop requires the use of a trampoline, which breaks tables-next-to- code. Two possible outcomes for this ticket are: * We somehow get proper Thumb2/Arm code interoperation working. * We decide that interop is too difficult or not worthwhile and a) document this somewhere in the code and b) remove the Thumb2 relocation code in `rts/Linker.c` and all other references to Thumb2. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10969> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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