September 2017 - ghc-tickets

[GHC] #9281: Rewrite `integer-gmp` to use only non-allocating GMP functions
by GHC 19 Sep '17

19 Sep '17

#9281: Rewrite `integer-gmp` to use only non-allocating GMP functions -------------------------------------+------------------------------------- Reporter: hvr | Owner: hvr Type: task | Status: new Priority: normal | Milestone: 7.10.1 Component: libraries (other) | Version: Keywords: integer-gmp | Operating System: Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | -------------------------------------+------------------------------------- After some promising results with a proof-of-concept implementation, I'm optimistic we can rewrite `integer-gmp` to use only non-allocating GMP lib functions without suffering from serious regressions. If successful, this would - allow to avoid the custom GMP allocator hack, and thus - avoid issues when linking against other C libraries using GMP, - simplify code, as we would perform all heap allocations in Haskell code (and never inside Cmm/C code as its done now), - and finally maybe even remove a few more superfluous temporary heap allocations. This rewrite can be done incrementally. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9281> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #14197: Flag "dump-rn-ast" only dumps the declarations, not the whole RenamedSource
by GHC 19 Sep '17

19 Sep '17

#14197: Flag "dump-rn-ast" only dumps the declarations, not the whole RenamedSource -------------------------------------+------------------------------------- Reporter: alanz | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 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: -------------------------------------+------------------------------------- `RenamedSource` is defined as {{{#!hs type RenamedSource = ( HsGroup Name , [LImportDecl Name] , Maybe [LIE Name] , Maybe LHsDocString) }}} The current behaviour when `dump-rn-ast` is set is to only dump the first component of this. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14197> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #13481: T12622 fails in ghci way
by GHC 19 Sep '17

19 Sep '17

#13481: T12622 fails in ghci way -------------------------------------+------------------------------------- Reporter: bgamari | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.2.1 Component: Compiler | Version: 8.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Compile-time Unknown/Multiple | crash or panic Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- `T12622`, which is intended to test StaticPointers, fails in the GHCi way with a core lint warning, {{{ *** Core Lint errors : in result of Float out(FOS {Lam = Just 0, Consts = True, OverSatApps = False}) *** <no location info>: warning: In the expression: >>= @ IO $fMonadIO @ (Bool -> Bool) @ () (break<10>(s_a1DF) lvl_s3bD) lvl_s3bE s_a1DF :: StaticPtr (Bool -> Bool) [LclId, Unf=Unf{Src=<vanilla>, TopLvl=False, Value=False, ConLike=False, WorkFree=False, Expandable=False, Guidance=IF_ARGS [] 70 0}] is out of scope *** Offending Program *** g :: Bool [LclIdX] g = break<15>() True $trModule_s3b7 :: Addr# [LclId] $trModule_s3b7 = "main"# $trModule_s3b6 :: TrName [LclId] $trModule_s3b6 = TrNameS $trModule_s3b7 $trModule_s3b9 :: Addr# [LclId] $trModule_s3b9 = "Main"# $trModule_s3b8 :: TrName [LclId] $trModule_s3b8 = TrNameS $trModule_s3b9 $trModule :: Module [LclIdX] $trModule = Module $trModule_s3b6 $trModule_s3b8 lvl_s3bj :: Addr# [LclId] lvl_s3bj = "error"# lvl_s3bk :: [Char] [LclId] lvl_s3bk = unpackCString# lvl_s3bj lvl_s3bl :: Addr# [LclId] lvl_s3bl = "main"# lvl_s3bm :: [Char] [LclId] lvl_s3bm = unpackCString# lvl_s3bl lvl_s3bn :: Addr# [LclId] lvl_s3bn = "Main"# lvl_s3bo :: [Char] [LclId] lvl_s3bo = unpackCString# lvl_s3bn lvl_s3bp :: Addr# [LclId] lvl_s3bp = "T12622.hs"# lvl_s3bq :: [Char] [LclId] lvl_s3bq = unpackCString# lvl_s3bp lvl_s3br :: Int [LclId] lvl_s3br = I# 21# lvl_s3bs :: Int [LclId] lvl_s3bs = I# 14# lvl_s3bt :: Int [LclId] lvl_s3bt = I# 21# lvl_s3bu :: Int [LclId] lvl_s3bu = I# 64# lvl_s3bv :: SrcLoc [LclId] lvl_s3bv = SrcLoc lvl_s3bm lvl_s3bo lvl_s3bq lvl_s3br lvl_s3bs lvl_s3bt lvl_s3bu lvl_s3bw :: ([Char], SrcLoc) [LclId] lvl_s3bw = (lvl_s3bk, lvl_s3bv) $dIP_s3bc :: CallStack [LclId] $dIP_s3bc = pushCallStack lvl_s3bw emptyCallStack lvl_s3bx :: Addr# [LclId] lvl_s3bx = "couldn't find "# lvl_s3by :: [Char] [LclId] lvl_s3by = unpackCString# lvl_s3bx lookupKey :: forall a. StaticPtr a -> IO a [LclIdX, Arity=1] lookupKey = \ (@ a_a23X) (p_X1DX :: StaticPtr a_a23X) -> break<8>(p_X1DX) >>= @ IO $fMonadIO @ (Maybe (StaticPtr a_a23X)) @ a_a23X (break<1>(p_X1DX) unsafeLookupStaticPtr @ a_a23X (break<0>(p_X1DX) staticKey @ a_a23X p_X1DX)) (\ (ds_d3as :: Maybe (StaticPtr a_a23X)) -> case ds_d3as of { Nothing -> break<7>(p_X1DX) error @ 'LiftedRep @ (IO a_a23X) ($dIP_s3bc `cast` (Sym (N:IP[0] <"callStack">_N <CallStack>_N) :: (CallStack :: *) ~R# ((?callStack::CallStack) :: Constraint))) (break<6>(p_X1DX) ++ @ Char lvl_s3by (break<5>(p_X1DX) show @ StaticPtrInfo $fShowStaticPtrInfo (break<4>(p_X1DX) staticPtrInfo @ a_a23X p_X1DX))); Just p_a1DI -> break<3>(p_a1DI) return @ IO $fMonadIO @ a_a23X (break<2>(p_a1DI) deRefStaticPtr @ a_a23X p_a1DI) }) $dTypeable_s3bA :: TypeRep Bool [LclId] $dTypeable_s3bA = mkTrCon @ * @ Bool $tcBool ([] @ SomeTypeRep) s_s3bC :: StaticPtr (Bool -> Bool) [LclId] s_s3bC = case break<9>() sg @ Bool ($dTypeable_s3bA `cast` (Sym N:Typeable[0] <*>_N <Bool>_N :: (TypeRep Bool :: *) ~R# (Typeable Bool :: Constraint))) of { T s_a38b -> s_a38b } lvl_s3bD :: IO (Bool -> Bool) [LclId] lvl_s3bD = lookupKey @ (Bool -> Bool) s_s3bC lvl_s3bE :: (Bool -> Bool) -> IO () [LclId] lvl_s3bE = \ (f_a1DG :: Bool -> Bool) -> break<12>(f_a1DG) print @ Bool $fShowBool (break<11>(f_a1DG) f_a1DG True) main :: IO () [LclIdX] main = break<14>() break<13>(s_s3bC) >>= @ IO $fMonadIO @ (Bool -> Bool) @ () (break<10>(s_a1DF) lvl_s3bD) lvl_s3bE main :: IO () [LclIdX] main = runMainIO @ () main *** End of Offense *** <no location info>: error: Compilation had errors *** Exception: ExitFailure 1 ===== program output begins here ===== program output begins here T12622:6:30: error: Not in scope: ‘Main.main’ No module named ‘Main’ is imported. }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13481> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #14096: Residency profiling with eventlog enabled breaks
by GHC 19 Sep '17

19 Sep '17

#14096: Residency profiling with eventlog enabled breaks -------------------------------------+------------------------------------- Reporter: bgamari | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.4.1 Component: Compiler | Version: 8.2.1 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: -------------------------------------+------------------------------------- The RTS panics when a program compiled with `-eventlog` is run with `+RTS -l -h`, {{{ trec-car-graph-expansion: internal error: getHeapProfBreakdown: unknown heap profiling mode Stack trace: 0x2122e2f set_initial_registers (rts/Libdw.c:288.0) 0x7f98bbdfb8b8 dwfl_thread_getframes (/usr/lib/x86_64 -linux-gnu/libdw-0.168.so) 0x7f98bbdfb347 (null) (/usr/lib/x86_64-linux- gnu/libdw-0.168.so) 0x7f98bbdfb673 dwfl_getthreads (/usr/lib/x86_64-linux- gnu/libdw-0.168.so) 0x7f98bbdfbc30 dwfl_getthread_frames (/usr/lib/x86_64 -linux-gnu/libdw-0.168.so) 0x212342d libdwGetBacktrace (rts/Libdw.c:259.0) 0x2127aab rtsFatalInternalErrorFn (rts/RtsMessages.c:169.0) 0x2127c6d barf (rts/RtsMessages.c:47.0) 0x2136824 postHeapProfBegin (rts/eventlog/EventLog.c:1147.0) 0x21443bb initHeapProfiling.part.5 (rts/ProfHeap.c:464.0) 0x211cc16 hs_init_ghc (rts/RtsStartup.c:268.0) 0x2128bb3 hs_main (rts/RtsMain.c:63.0) 0x4cfc8d (null) (/home/ben/trec-car/mediawiki- annotate/dist-newstyle/build/x86_64-linux/ghc-8.2.1/trec-car-graph- expansion-0.1.0.0/c/trec-car-graph-expansion/bu ild/trec-car-graph-expansion/trec-car-graph-expansion) 0x7f98bba4a2b1 __libc_start_main (../csu/libc- start.c:325.0) 0x40ba1a _start (/home/ben/trec-car/mediawiki- annotate/dist-newstyle/build/x86_64-linux/ghc-8.2.1/trec-car-graph- expansion-0.1.0.0/c/trec-car-graph-expansion/bu ild/trec-car-graph-expansion/trec-car-graph-expansion) (GHC version 8.2.1 for x86_64_unknown_linux) Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14096> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #14163: Stack Overflow with ApplicativeDo
by GHC 19 Sep '17

19 Sep '17

#14163: Stack Overflow with ApplicativeDo -------------------------------------+------------------------------------- Reporter: lippling | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Keywords: | Operating System: MacOS X Architecture: x86_64 | Type of failure: Compile-time (amd64) | crash or panic Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- I tried to compile one of our server applications with 8.2.1 (which compiles fine with 8.0.2). The compilation runs smooth, but when it reaches a specific file, the RAM usage goes up to > 20GB pretty fast on my 16GB machine and the GHC process gets terminated with a stack overflow error. I tried to find a minimal example that causes this behavior: {{{ #!/usr/bin/env stack -- stack --resolver nightly-2017-08-25 script {-# LANGUAGE ApplicativeDo #-} x = do (a, _) <- undefined (b, _) <- undefined (c, _) <- undefined undefined main = undefined }}} It only happens with at least 3 of these pattern matches. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14163> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #14228: PatternSynonyms Non-exhaustive with UnboxedSums
by GHC 19 Sep '17

19 Sep '17

#14228: PatternSynonyms Non-exhaustive with UnboxedSums -------------------------------------+------------------------------------- Reporter: guibou | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Keywords: UnboxedSum, | Operating System: Unknown/Multiple PatternSynonyms | Architecture: | Type of failure: Incorrect result Unknown/Multiple | at runtime Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- The following implementation of `Maybe` using UnboxedSums results in `Non- exhaustive patterns in case`: (`Failure.hs` file) {{{#!haskell {-# LANGUAGE UnboxedSums #-} {-# LANGUAGE PatternSynonyms #-} type Maybe' t = (# t | () #) pattern Just' :: a -> Maybe' a pattern Just' x = (# x | #) pattern Nothing' :: Maybe' a pattern Nothing' = (# | () #) foo x = case x of Nothing' -> putStrLn "nothing" Just' _ -> putStrLn "just" main = do putStrLn "Nothing'" foo Nothing' putStrLn "Just'" foo (Just' "hello") }}} When executed, it prints: {{{ Nothing' nothing Just' Failure: Failure.hs:10:20-29: Non-exhaustive patterns in case }}} Compiled with `ghc Failure.hs`. Please note that by removing the `pattern`s, and writting `foo` as following works as expected: {{{#!haskell foo x = case x of (# | () #) -> putStrLn "nothing" (# _ | #) -> putStrLn "just" }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14228> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #14189: Renamer does not preserve location for IEThingWith list items
by GHC 19 Sep '17

19 Sep '17

#14189: Renamer does not preserve location for IEThingWith list items -------------------------------------+------------------------------------- Reporter: alanz | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Incorrect API Unknown/Multiple | annotation Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- In the `RenamedSource` for {{{#!hs module Renaming.RenameInExportedType ( MyType (NT) ) where data MyType = MT Int | NT }}} The `(NT)` is given the location of `MyType` earlier on the line in the export list. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14189> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #14158: (Control.Category.id @(->) >>=) causes GHC panic
by GHC 19 Sep '17

19 Sep '17

#14158: (Control.Category.id @(->) >>=) causes GHC panic -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 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: -------------------------------------+------------------------------------- {{{ $ ghci -ignore-dot-ghci -XTypeApplications GHCi, version 8.3.20170605: http://www.haskell.org/ghc/ :? for help Prelude> import qualified Control.Category as Cat Prelude Cat> :t (Cat.id @(->) >>=) ghc: panic! (the 'impossible' happened) (GHC version 8.3.20170605 for x86_64-unknown-linux): repSplitAppTy_maybe a0_a1qW[tau:2] a0_a1qW[tau:2] Call stack: CallStack (from HasCallStack): prettyCurrentCallStack, called at compiler/utils/Outputable.hs:1133:58 in ghc:Outputable callStackDoc, called at compiler/utils/Outputable.hs:1137:37 in ghc:Outputable pprPanic, called at compiler/types/Type.hs:699:5 in ghc:Type Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug Prelude Cat> }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14158> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #13525: hWaitForInput with timeout causes program to abort
by GHC 19 Sep '17

19 Sep '17

#13525: hWaitForInput with timeout causes program to abort --------------------------------------+---------------------------------- Reporter: bgamari | Owner: (none) Type: bug | Status: new Priority: high | Milestone: 8.2.1 Component: Compiler | Version: 8.0.2 Keywords: | Operating System: Linux Architecture: x86_64 (amd64) | Type of failure: Runtime crash Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: --------------------------------------+---------------------------------- This program, {{{#!hs import System.IO import System.Timeout main = hWaitForInput stdin (5 * 1000) }}} causes the program to abort (tested on Linux), {{{ $ ghc hi.hs [1 of 1] Compiling Main ( hi.hs, hi.o ) Linking hi ... $ ./hi fdReady: msecs != 0, this shouldn't happenAborted }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13525> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9157: cmm common block not eliminated
by GHC 19 Sep '17

19 Sep '17

#9157: cmm common block not eliminated ------------------------------------+------------------------------------- Reporter: wojteknar | 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: Other Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+------------------------------------- For the toTuple# function (in the attached file) GHC generates a cmm switch statement, with all the alternatives, unsurprisingly, the same. Yet, cmm common block elimination does not kick in. In this particular example, the whole case statement could be annihilated, because all alternatives lead to the same code. BTW, this is how they match in France. {{{ #!ocaml type alt = A of int | B of int | C of int | D of int let g x = match x with A v | B v | C v | D v -> v }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9157> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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