October 2015 - ghc-devs

New error on linux
by Simon Peyton Jones 27 Oct '15

27 Oct '15

Clean build on HEAD on Linux is now giving a new error. Actual stderr output differs from expected: --- ./driver/T10970a.stderr.normalised 2015-10-27 09:44:02.279188078 +0000 +++ ./driver/T10970a.comp.stderr.normalised 2015-10-27 09:44:02.279188078 +0000 @@ -1,6 +1,4 @@ T10970a.hs:4:0: missing binary operator before token "(" - #if MIN_VERSION_base(3,0,0) - ^ `gcc' failed in phase `C pre-processor'. (Exit code: 1) I figured out the recomp013 problem; there was a commit which interacted badly with link trees commit cdca31ebf7744dcae66a6715500395a63bcc3ee2 Author: Edward Z. Yang <ezyang(a)cs.stanford.edu> Date: Wed Sep 9 22:02:48 2015 -0700 Don't check in autogenerated hs files for recomp013..

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stg_upd_frame_info still broken
by Simon Peyton Jones 27 Oct '15

27 Oct '15

Friends I still cannot build GHC on Windows. On Ben's advice I dumped my current msys setup and re-installed msys64 as described here https://ghc.haskell.org/trac/ghc/wiki/Building/Preparation/Windows I cloned an entirely new GHC repository. Then 'sh validate'. Same result as before: any attempt to run GHCi fails with an unresolved symbol. bash$ c:/code/HEAD-1/inplace/bin/ghc-stage2 --interactive GHCi, version 7.11.20151026: http://www.haskell.org/ghc/ :? for help ghc-stage2.exe: unable to load package `ghc-prim-0.4.0.0' ghc-stage2.exe: C:\code\HEAD-1\libraries\ghc-prim\dist-install\build\HSghc-prim-0.4.0.0.o: unknown symbol `_stg_upd_frame_info' How could I actually find what the problem is? Trying random things and hoping the problem goes away clearly is not working. Very stuck and deeply frustrated Thanks Simon

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Segfault in a CoreLinted program (and a GHC-generated Core question)
by Ömer Sinan Ağacan 27 Oct '15

27 Oct '15

I have a very simple Core plugin that generates some functions. After my Core-to-Core pass is done, I'm running the linter to make sure the Core generated by my plugin is well-formed and well-typed. However, even though lint checker passes, the code generated by my plugin is failing with a segfault. I created a git repo for demonstration: https://github.com/osa1/plugins This is where the CoreLint is happening: https://github.com/osa1/plugins/blob/master/src/Plugins.hs#L38 I'm using GHC HEAD(it doesn't build with 7.10). Here's how to run: Make sure GHC HEAD is in the $PATH, then $ cabal install --with-ghc=ghc-stage2 $ cd test Adding bunch of -ddump parameters here for debugging purposes: $ ghc-stage2 -fplugin=Plugins --make Main.hs -fforce-recomp -ddump-simpl -ddump-ds -ddump-to-file -ddump-stg Now if you run the generated program, it should first print some numbers and then segfault. --- I heard from Simon in various talks(e.g. Haskell exchange 2015) that if lint passes, then there should be no segfaults, so I thought this should be a bug. I'm actually having some other problems with CoreLint too, for example, even though Core lint passes, if I run Core simplifier pass after my plugin runs, GHC is failing with various different panics. Some of those panics are happening inside STG generation, not in simplifier(but it works fine if I disable the simplifier!) It seems like CoreLint is not strict enough, it's not checking some invariants that GHC simplifier and STG code generator are assuming. So my questions are: Am I right in assuming that CoreLint accepted programs should not segfault? What about internal invariants? Should CoreLint check for those? Is there any pass that checks for invariants and prints helpful messages in case of a invariant invalidation? As an attempt at debugging the code generated by my plugin, I wrote the function that is supposed to be generated by my Core pass in Haskell and compiled with GHC. Generated Core is mostly the same, except at one point it has an extra lambda directly applied to a void#, something like ((\_ -> ...) void#). Where can I learn more about why GHC is doing that? Thanks.

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Doc warnings
by Simon Peyton Jones 27 Oct '15

27 Oct '15

I'm getting these warnings relating to the user manual. They seem non-fatal, but are alarming. Simon reading sources... [ 66%] ghc looking for now-outdated files... none found pickling environment... done checking consistency... /5playpen/simonpj/HEAD-2/docs/users_guide/ghc.rst:: WARNING: document isn't included in any toctree done writing... ghc.1 { WARNING: file compiler/simplCore/SimplCore.hs, line 600 Simplifier bailing out after 4 iterations [6069, 1479, 780, 43] Size = {terms: 5,210, types: 10,459, coercions: 2,136} Interesting! A join var that isn't let-no-escaped [$j_snPt] } build succeeded, 1 warning. reading sources... [100%] glasgow_exts WARNING: file compiler/simplCore/SimplEnv.hs, line 528 go_Xn2R WARNING: file compiler/simplCore/SimplEnv.hs, line 528 go_Xn2R looking for now-outdated files... none found pickling environment... done checking consistency... /5playpen/simonpj/HEAD-2/docs/users_guide/ghc.rst:: WARNING: document isn't included in any toctree done preparing documents... done

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dll-split
by Simon Peyton Jones 27 Oct '15

27 Oct '15

It's just not my day. Now, on Linux, on my branch wip/spj-wildcard-refactor, I get a failure in dll-split! Should dll-split be running at all on Linux???? The output it produces is below. I'm totally stuck. Help desperately needed. Simon inplace/bin/dll-split compiler/stage2/build/.depend-v-p-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 CoreSeq CoreStats CostCentre Ctype DataCon Demand Digraph DriverPhases DynFlags Encoding ErrUtils Exception FamInstEnv FastFunctions FastMutInt FastString FastStringEnv FieldLabel Fingerprint FiniteMap ForeignCall Hooks HsBinds HsDecls HsDoc HsExpr HsImpExp HsLit PlaceHolder HsPat HsSyn HsTypes HsUtils HscTypes IOEnv Id IdInfo IfaceSyn IfaceType InstEnv Kind Lexeme Lexer 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 CmmSwitch 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 Hoopl Hoopl.Dataflow InteractiveEvalTypes MkGraph PprCmm PprCmmDecl PprCmmExpr Reg RegClass SMRep StgCmmArgRep StgCmmClosure StgCmmEnv StgCmmLayout StgCmmMonad StgCmmProf StgCmmTicky StgCmmUtils StgSyn Stream" Reachable modules from DynFlags out of date Please fix compiler/ghc.mk, or building DLLs on Windows may break (#7780) Redundant modules: Ctype Lexer simonpj@cam-05-unx:~/5builds/HEAD-2$

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Can't build on Windows
by Simon Peyton Jones 27 Oct '15

27 Oct '15

Gurgah. GHC is broken on my windows laptop. See below. Anyone have any ideas? Frustrating. Oddly the symbol is defined in the .exe bash$ nm inplace/bin/ghc-stage2.exe | grep stg_upd_frame 02c248e0 T _stg_upd_frame_info This is admittedly on a branch that I have modified; but I have only modified stuff in the front end, nothing in the RTS etc. I suppose I will try to build a unmodified HEAD too. can anyone help? Thanks! Simon bash$ c:/code/HEAD/inplace/bin/ghc-stage2 --interactive GHCi, version 7.11.20151026: http://www.haskell.org/ghc/ :? for help ghc-stage2.exe: unable to load package `ghc-prim-0.4.0.0' ghc-stage2.exe: C:\code\HEAD\libraries\ghc-prim\dist-install\build\HSghc-prim-0.4.0.0.o: unknown symbol `_stg_upd_frame_info' HEAD $

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can't get haddock patch
by Simon Peyton Jones 26 Oct '15

26 Oct '15

Ben What does this mean? (below) Does it mean you have not pushed something to the haddock repo> This happens when I'm on branch wip/T9858-typeable-ben2, in the main repo Simon git submodule update fatal: reference is not a tree: 289ef817aad02c341beb6d4c28ba0495872f5a0f Unable to checkout '289ef817aad02c341beb6d4c28ba0495872f5a0f' in submodule path 'utils/haddock' simonpj@cam-05-unx:~/code/HEAD-2$

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recomp013
by Simon Peyton Jones 26 Oct '15

26 Oct '15

driver/recomp013 is failing, on Linux, on HEAD for me: Actual stdout output differs from expected: --- ./driver/recomp013/recomp013.stdout.normalised 2015-10-26 14:26:51.920153558 +0000 +++ ./driver/recomp013/recomp013.run.stdout.normalised 2015-10-26 14:26:51.920153558 +0000 @@ -3,5 +3,3 @@ [2 of 3] Compiling B ( B.hs, B.o ) [3 of 3] Compiling C ( C.hs, C.o ) second run -[2 of 3] Compiling B ( B.hs, B.o ) -[3 of 3] Compiling C ( C.hs, C.o ) [B changed]

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Sphinx on Windows
by Simon Peyton Jones 26 Oct '15

26 Oct '15

The GHC wiki says you need Sphinx to build docs, https://ghc.haskell.org/trac/ghc/wiki/Building/Preparation/Tools and refers to the Preparation doc for how to install Sphinx https://ghc.haskell.org/trac/ghc/wiki/Building/Preparation But the Windows sub-page of Preparation does not say how to install Sphinx. Question: how does one install Sphinx on Windows? The sphinx-doc home page mutters about 'pip', but I've never used that. Does anyone have instructions? Thanks Simon

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Can't push to haddock repo
by Simon Peyton Jones 26 Oct '15

26 Oct '15

I can't update the haddock repository! (I want to add a new branch for my in-flight work.) Can anyone help? Thanks Simon git push --set-upstream origin wip/spj-wildcard-refactor remote: W refs/heads/wip/spj-wildcard-refactor haddock simonpj DENIED by refs/.* remote: error: hook declined to update refs/heads/wip/spj-wildcard-refactor To ssh://git@git.haskell.org/haddock.git ! [remote rejected] wip/spj-wildcard-refactor -> wip/spj-wildcard-refactor (hook declined) error: failed to push some refs to 'ssh://git@git.haskell.org/haddock.git' haddock $

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