October 2015 - ghc-tickets

Re: [GHC] #3242: ghci: can't load .so/.DLL for: m (addDLL: could not load DLL)
by GHC 28 Oct '15

28 Oct '15

#3242: ghci: can't load .so/.DLL for: m (addDLL: could not load DLL) ---------------------------------+----------------------------- Reporter: jeffz1 | Owner: Phyx- Type: bug | Status: new Priority: high | Milestone: 8.0.1 Component: GHCi | Version: 7.4.1 Resolution: | Keywords: Operating System: Windows | Architecture: x86 Type of failure: None/Unknown | Test Case: Blocked By: 3658 | Blocking: Related Tickets: #7097 | Differential Rev(s): Wiki Page: | ---------------------------------+----------------------------- Changes (by RyanGlScott): * cc: RyanGlScott (added) -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/3242#comment:39> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11023: ghci and ghc-pkg disagree about what's exposed
by GHC 28 Oct '15

28 Oct '15

#11023: ghci and ghc-pkg disagree about what's exposed -------------------------------------+------------------------------------- Reporter: dmwit | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Package | Version: 7.10.2 system | 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: -------------------------------------+------------------------------------- I have installed vector-0.10.12.3 and vector-0.11.0.0. At some point, I had hidden both from the package database; however, I later used ghc-pkg expose to mark one as visible again. Now I seem to be in a strange state where ghci and ghc-pkg disagree about what is hidden: {{{ % ghci-7.10.2 GHCi, version 7.10.2: http://www.haskell.org/ghc/ :? for help Prelude> :m +Data.Vector.Unboxed <no location info>: Could not find module ‘Data.Vector.Unboxed’ It is a member of the hidden package ‘vector-0.11.0.0@vecto_3jMaUrldidp1bqsrn0qsS2’. It is a member of the hidden package ‘vector-0.10.12.3@vecto_1COyUuV1LrA1IjYnWfJnbs’. Prelude> Leaving GHCi. % ghc-pkg-7.10.2 list vector | cat /usr/local/lib/ghc-7.10.2/package.conf.d: (no packages) /home/dmwit/.ghc/x86_64-linux-7.10.2/package.conf.d: vector-0.10.12.3 (vector-0.11.0.0) % ghc-pkg-7.10.2 describe vector-0.10.12.3 | grep 'key:\|exposed:' key: vecto_1COyUuV1LrA1IjYnWfJnbs exposed: True }}} I have tried reproducing this with other packages in a handful of ways and failed; so I can't give instructions for reproducing. But I am happy to perform any diagnostics you can think of. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11023> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11029: Performance loss due to eta expansion
by GHC 28 Oct '15

28 Oct '15

#11029: Performance loss due to eta expansion -------------------------------------+------------------------------------- Reporter: NeilMitchell | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.2 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Runtime Unknown/Multiple | performance bug Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- Given the attached file, at both {{{-O2}}} and {{{-O0}}}, GHC translates the function: {{{#!hs test1 [1,2,3,4,5,6,7,8,9,10] = \x -> x test1 _ = \x -> negate x }}} To be equivalent to: {{{#!hs test0 [1,2,3,4,5,6,7,8,9,10] x = x test0 _ x = negate x }}} When applied in a loop with something like: {{{#!hs map (test1 [1..]) [1..1000] }}} The eta-expanded variant is 3x slower. Adding a trace breaks that transformation, and then the code goes 3x faster. Specifically: {noformat} test2 [1,2,3,4,5,6,7,8,9,10] = \x -> x test2 _ = trace "here" $ \x -> negate x {noformat} Timings, as reported by Criterion under O2 with GHC 7.10.2, are: {{{ benchmarking test0 = 40.99 ns (40.96 ns .. 41.02 ns) benchmarking test1 = 41.09 ns (41.06 ns .. 41.14 ns) benchmarking test2 = 17.74 ns (17.68 ns .. 17.81 ns) }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11029> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11010: Untouchable type, pattern synonyms
by GHC 28 Oct '15

28 Oct '15

#11010: Untouchable type, pattern synonyms ------------------------------------+--------------------------------- Reporter: Iceland_jack | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.2 Keywords: | Operating System: Linux Architecture: x86 | Type of failure: None/Unknown Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: ------------------------------------+--------------------------------- GHC panicked while experimenting {{{#!hs {-# LANGUAGE PatternSynonyms, ExistentialQuantification, GADTSyntax #-} module Test where data Expr a where Fun :: String -> (a -> b) -> (Expr a -> Expr b) pattern IntFun :: () => (a ~ Int) => String -> (a -> b) -> (Expr a -> Expr b) pattern IntFun str f x = Fun str f x pattern Suc :: () => (a ~ Int) => Expr a -> Expr Int pattern Suc n <- IntFun _ _ n where Suc n = IntFun "suc" (+ 1) n }}} {{{ % ghc Test.hs [1 of 1] Compiling Test ( Test.hs, Test.o ) Test.hs:12:18: Couldn't match expected type ‘Int’ with actual type ‘a1’ ‘a1’ is untouchable inside the constraints (a ~ Int) bound by the type signature for Suc :: Expr a -> Expr Int at Test.hs:12:9-11ghc: panic! (the 'impossible' happened) (GHC version 7.10.2 for i386-unknown-linux): No skolem info: a1_anA[ssk] Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11010> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10999: ghc: panic! (the 'impossible' happened)
by GHC 27 Oct '15

27 Oct '15

#10999: ghc: panic! (the 'impossible' happened) -------------------------------------+------------------------------------- Reporter: res | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.2 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Compile-time Unknown/Multiple | crash Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- The attached program elicits the following error from GHC 7.10.2: {{{ Couldn't match type ‘a’ with ‘(t0, t1, t2)’ ‘a’ is untouchable inside the constraints () bound by the inferred type of updateKeytab :: FilePath -> Handle -> IO () at /u/res/g/src/remctl-tools/foo.hs:(58,1)-(69,26)ghc: panic! (the 'impossible' happened) (GHC version 7.10.2 for x86_64-unknown-linux): No skolem info: a_akOb[sk] Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10999> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #4012: Compilation results are not deterministic
by GHC 27 Oct '15

27 Oct '15

#4012: Compilation results are not deterministic -------------------------------------+------------------------------------- Reporter: kili | Owner: niteria Type: bug | Status: patch Priority: high | Milestone: 8.0.1 Component: Compiler | Version: 6.12.2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: Other | Test Case: Blocked By: | Blocking: Related Tickets: #10424 | Differential Rev(s): Phab:D910, | Phab:D1073, Phab:D1133, Phab:D1192, Wiki Page: | Phab:D1268 -------------------------------------+------------------------------------- Comment (by Austin Seipp <austin@…>): In [changeset:"ffcdd84f86727c1621be0a0e522eb6a3a64e479f/ghc" ffcdd84/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="ffcdd84f86727c1621be0a0e522eb6a3a64e479f" Sort field labels before fingerprint hashing `fsEnvElts :: FastStringEnv a -> [a]` returns a list of `[a]` in the order of `Unique`s which is arbitrary. In this case it gives a list of record fields in arbitrary order, from which we then extract the field labels to contribute to the record fingerprint. The arbitrary ordering of field labels introduces unnecessary nondeterminism in interface files as demonstrated by the test case. We sort `FastString` here. It's safe, because the only way that the `Unique` associated with the `FastString` is used in comparison is for equality. If the `Unique`s are different it fallbacks to comparing the actual `ByteString`. Reviewed By: ezyang, thomie, bgamari, austin Differential Revision: https://phabricator.haskell.org/D1373 GHC Trac Issues: #4012 }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/4012#comment:128> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #4012: Compilation results are not deterministic
by GHC 27 Oct '15

27 Oct '15

#4012: Compilation results are not deterministic -------------------------------------+------------------------------------- Reporter: kili | Owner: niteria Type: bug | Status: patch Priority: high | Milestone: 8.0.1 Component: Compiler | Version: 6.12.2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: Other | Test Case: Blocked By: | Blocking: Related Tickets: #10424 | Differential Rev(s): Phab:D910, | Phab:D1073, Phab:D1133, Phab:D1192, Wiki Page: | Phab:D1268 -------------------------------------+------------------------------------- Comment (by Ben Gamari <ben@…>): In [changeset:"158d2a91581d82dc1690a858b474eaab3a02e43e/ghc" 158d2a9/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="158d2a91581d82dc1690a858b474eaab3a02e43e" Make it possible to have different UniqSupply strategies To get reproducible/deterministic builds, the way that the Uniques are assigned shouldn't matter. This allows to test for that. It add 2 new flags: * `-dinitial-unique` * `-dunique-increment` And by varying these you can get interesting effects: * `-dinitial-unique=0 -dunique-increment 1` - current sequential UniqSupply * `-dinitial-unique=16777215 -dunique-increment -1` - UniqSupply that generates in decreasing order * `-dinitial-unique=1 -dunique-increment PRIME` - where PRIME big enough to overflow often - nonsequential order I haven't proven the usefullness of the last one yet and it's the reason why we have to mask the bits with `0xFFFFFF` in `genSym`, so I can remove it if it becomes contentious. Test Plan: validate on harbormaster Reviewers: simonmar, austin, ezyang, bgamari Reviewed By: austin, bgamari Subscribers: thomie Differential Revision: https://phabricator.haskell.org/D1360 GHC Trac Issues: #4012 }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/4012#comment:127> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #6119: complain when ghc-pkg doesn't find any matching packages in a given database
by GHC 26 Oct '15

26 Oct '15

#6119: complain when ghc-pkg doesn't find any matching packages in a given database -------------------------------------+------------------------------------- Reporter: dmwit | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: ghc-pkg | Version: 7.4.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #10785 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by thomie): * component: Compiler => ghc-pkg * related: => #10785 -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/6119#comment:4> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #6119: complain when ghc-pkg doesn't find any matching packages in a given database
by GHC 26 Oct '15

26 Oct '15

#6119: complain when ghc-pkg doesn't find any matching packages in a given database -------------------------------------+------------------------------------- Reporter: dmwit | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.4.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by dmwit): * status: closed => new * resolution: fixed => Comment: GHC has since grown a colored version of ghc-pkg, which did not inherit this nice feature. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/6119#comment:3> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11013: GHC sometimes forgets to test for hs-boot consistency
by GHC 26 Oct '15

26 Oct '15

#11013: GHC sometimes forgets to test for hs-boot consistency -------------------------------------+------------------------------------- Reporter: ezyang | Owner: Type: bug | Status: new Priority: low | Milestone: Component: Compiler | Version: 7.11 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: GHC accepts Unknown/Multiple | invalid program Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- Steps to reproduce: create your classic circular dependency: {{{ -- A.hs-boot module A where }}} {{{ -- B.hs module B where import {-# SOURCE #-} A }}} {{{ -- A.hs module A where import B }}} Now run this: {{{ ghc -c A.hs-boot ghc -c B.hs ghc -c A.hs echo "module A where x :: Bool" > A.hs-boot ghc -c A.hs-boot ghc -c B.hs ghc -c A.hs }}} Expected result: A.hs recompiles and gives us an error that we don't implement enough. Actual result: compilation IS NOT required. (Obviously, if you force recomp you do get an error now.) I think the problem is `checkOldIface` doesn't also look for an hi-boot file, and even if it did, we don't record the hashes from the hi-boot file in the hi file proper (they're not an immediate dependency). Related #10333 -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11013> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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