October 2018 - ghc-tickets

[GHC] #15812: add System.Mem.Address to base
by GHC 26 Nov '18

26 Nov '18

#15812: add System.Mem.Address to base -------------------------------------+------------------------------------- Reporter: carter | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.8.1 Component: | Version: 8.7 libraries/base | Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): D5268 | Wiki Page: -------------------------------------+------------------------------------- per libraries in progress discussion and https://phabricator.haskell.org/D5268 current state is this {{{ {-# LANGUAGE MagicHash #-} Module System.Mem.Address ( -- * Types Addr(..), -- * Address arithmetic nullAddr, plusAddr, minusAddr, remAddr, -- * Conversion addrToInt, addrToPtr, ptrToAddr ) where import GHC.Base ( Int(..) ) import GHC.Prim import GHC.Exts (isTrue#) import GHC.Ptr import Foreign.Marshal.Utils import Data.Typeable ( Typeable ) import Data.Data ( Data(..), mkNoRepType ) -- | A machine address data Addr = Addr Addr# deriving ( Typeable ) instance Show Addr where showsPrec _ (Addr a) = showString "0x" . showHex (fromIntegral (I# (addr2Int# a)) :: Word) instance Eq Addr where Addr a# == Addr b# = isTrue# (eqAddr# a# b#) Addr a# /= Addr b# = isTrue# (neAddr# a# b#) instance Ord Addr where Addr a# > Addr b# = isTrue# (gtAddr# a# b#) Addr a# >= Addr b# = isTrue# (geAddr# a# b#) Addr a# < Addr b# = isTrue# (ltAddr# a# b#) Addr a# <= Addr b# = isTrue# (leAddr# a# b#) instance Data Addr where toConstr _ = error "toConstr" gunfold _ _ = error "gunfold" dataTypeOf _ = mkNoRepType "Data.Primitive.Types.Addr" -- | The null address nullAddr :: Addr nullAddr = Addr nullAddr# infixl 6 `plusAddr`, `minusAddr` infixl 7 `remAddr` -- | Offset an address by the given number of bytes plusAddr :: Addr -> Int -> Addr plusAddr (Addr a#) (I# i#) = Addr (plusAddr# a# i#) -- | Distance in bytes between two addresses. The result is only valid if the -- difference fits in an 'Int'. minusAddr :: Addr -> Addr -> Int minusAddr (Addr a#) (Addr b#) = I# (minusAddr# a# b#) -- | The remainder of the address and the integer. remAddr :: Addr -> Int -> Int remAddr (Addr a#) (I# i#) = I# (remAddr# a# i#) -- | Convert an 'Addr' to an 'Int'. addrToInt :: Addr -> Int {-# INLINE addrToInt #-} addrToInt (Addr addr#) = I# (addr2Int# addr#) -- | convert `Addr` to `Ptr a` addrToPtr :: Addr -> Ptr a addrToPtr (Addr addr#) = Ptr addr# -- | convert `Ptr a` to `Addr` ptrToAddr :: Ptr a -> Addr ptrToAddr (Ptr p) = Addr p }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15812> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #12965: String merging broken on Windows
by GHC 26 Nov '18

26 Nov '18

#12965: String merging broken on Windows ----------------------------------------+--------------------------------- Reporter: bgamari | Owner: Type: bug | Status: new Priority: normal | Milestone: 8.2.1 Component: Compiler | Version: 8.0.1 Keywords: | Operating System: Windows Architecture: Unknown/Multiple | Type of failure: None/Unknown Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: ----------------------------------------+--------------------------------- #9577 introduced string literal merging via the linker. Unfortunately I haven't been able to get this to function on Windows, resulting in testsuite failures of #9577. Even `gcc` appears to do the wrong thing here, {{{ $ cat hi.c #include <stdio.h> const char *hi = "hello world"; extern const char *hi2; void main() { printf("%p %p", hi, hi2); } $ cat hi2.c const char *hi2 = "hello world"; $ gcc -c hi.c; gcc -c hi2.c; gcc -fmerge-all-constants hi2.o hi.o $ ./a.exe 0x100403040 0x100403030 $ gcc -s hi2.c $ cat hi2.s .file "hi2.c" .globl hi .section .rdata,"dr" .LC0: .ascii "hello world\0" .data .align 8 hi: .quad .LC0 .ident "GCC: (GNU) 5.3.0" }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12965> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #14482: GHC -M mode fails to ensure that boot files are built before source files
by GHC 26 Nov '18

26 Nov '18

#14482: GHC -M mode fails to ensure that boot files are built before source files -------------------------------------+------------------------------------- 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: -------------------------------------+------------------------------------- Imagine we have a module with a boot file. In general it is necessary to ensure that we compile the boot file *before* the source file to ensure that the `hi-boot` file exists when we go to typecheck the module (triggering the behavior observed in #14481). However, `ghc -M` doesn't guarantee this. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14482> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #15019: Fix performance regressions from #14737
by GHC 26 Nov '18

26 Nov '18

#15019: Fix performance regressions from #14737 -------------------------------------+------------------------------------- Reporter: tdammers | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.6.1 Component: Compiler | Version: Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Compile-time Unknown/Multiple | performance bug Test Case: | Blocked By: Blocking: | Related Tickets: #14737 Differential Rev(s): D4568 | Wiki Page: -------------------------------------+------------------------------------- #14737, while drastically improving performance on some edge cases, introduces performance regressions in 3 test cases: perf/compiler/parsing001.run perf/compiler/T9020.run perf/compiler/T12707.run -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15019> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #15366: GHC.Conc.Windows has a surprising queue
by GHC 26 Nov '18

26 Nov '18

#15366: GHC.Conc.Windows has a surprising queue -------------------------------------+------------------------------------- Reporter: dfeuer | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.8.1 Component: Core | Version: 8.4.3 Libraries | 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: -------------------------------------+------------------------------------- `GHC.Conc.Windows` seems to use `[DelayReq]` as a priority queue, and uses `foldr` to insert multiple elements into it. Unless these lists are always very short (are they?) that seems like a bad idea. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15366> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #15732: getArgsWithResponseFiles does not filter out RTS options
by GHC 26 Nov '18

26 Nov '18

#15732: getArgsWithResponseFiles does not filter out RTS options -------------------------------------+------------------------------------- Reporter: ckoparkar | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.8.1 Component: | Version: 8.6.1 libraries/base | Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Incorrect result Unknown/Multiple | at runtime Test Case: | Blocked By: Blocking: | Related Tickets: #13896 Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- I discovered this while working on a fix for #15072. {{{GHC.ResponseFile.getArgsWithResponseFiles}}} is a recent addition to {{{base-4.12}}}. The idea was to have a function which could read command- line arguments supplied via response files, but otherwise would behave exactly like `System.Environment.getArgs` (see #13896). However, these functions return different results when RTS options are supplied. 1. {{{getArgs}}} does not include RTS options in the list it returns. 2. {{{getArgsWithResponseFiles}}} includes them. It's trivial to reproduce this. Consider these files: {{{ -- Bug1.hs module Main where import System.Environment ( getArgs ) main :: IO () main = do args <- getArgs putStrLn $ "Args: " ++ show args }}} and {{{ -- Bug2.hs module Main where import GHC.ResponseFile ( getArgsWithResponseFiles ) main :: IO () main = do args <- getArgsWithResponseFiles putStrLn $ "ArgsResp: " ++ show args }}} And run them with: {{{#!sh $ ghc-8.6.1 -rtsopts Bug1.hs && ghc-8.6.1 -rtsopts Bug2.hs $ ./Bug1 1 +RTS -H32m -RTS 10 20 Args: ["1","10","20"] -- 'opts_file' contains the same arguments passed to Bug1, and we -- use a '@' to pass it as a response file $ ./Bug2 @opts_file ArgsResp: ["1","+RTS","-H32m","-RTS","10","20"] }}} We should fix {{{getArgsWithResponseFiles}}} to properly handle {{{+RTS ... -RTS}}} and {{{--RTS}}} flags. Currently, {{{getArgs}}} relies on the [http://git.haskell.org/ghc.git/blob/HEAD:/rts/RtsFlags.c#l661 runtime system] for filtering out appropriate things. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15732> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #14534: Split T12971 into its own Makefile
by GHC 26 Nov '18

26 Nov '18

#14534: Split T12971 into its own Makefile -------------------------------------+------------------------------------- Reporter: dfeuer | Owner: (none) Type: task | Status: new Priority: low | Milestone: 8.6.1 Component: Test Suite | Version: 8.2.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Other Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- `testsuite/tests/driver/Makefile` includes the `T12971` target. This (intentionally) has non-ASCII characters in it. As a result, any change to that makefile will trigger a lint error. We should give that test its own makefile to isolate it a bit. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14534> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #15484: MultiLayerModules and T13701 timeout on i386 Linux
by GHC 26 Nov '18

26 Nov '18

#15484: MultiLayerModules and T13701 timeout on i386 Linux -------------------------------------+------------------------------------- Reporter: bgamari | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.6.1 Component: Compiler | Version: 8.4.3 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: -------------------------------------+------------------------------------- CircleCI's Linux/i386 configuration fails with timeouts on `MultiLayerModules`, `T13701`, -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15484> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #15706: Refactor NewHsTypeX to DerivedCoreTy
by GHC 26 Nov '18

26 Nov '18

#15706: Refactor NewHsTypeX to DerivedCoreTy -------------------------------------+------------------------------------- Reporter: int-index | Owner: (none) Type: task | Status: new Priority: low | Milestone: 8.8.1 Component: Compiler | Version: 8.6.1 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: -------------------------------------+------------------------------------- `NewHsTypeX` is not a good name for this construct: {{{ data NewHsTypeX = NHsCoreTy Type -- An escape hatch for tunnelling a *closed* -- Core Type through HsSyn. }}} * the `New` prefix refers to the fact that it is a new approach, rather than to a property of the entity * it is not suggestive of the way `NewHsTypeX` is used in the code and why it exists A better name would be `DerivedCoreTy`. The reason for `NHsCoreTy` existence and its invariant of being closed is the `deriving` mechanism. Doing this renaming also exposes incorrect uses of `NHsCoreTy` in a couple of places that violate the invariant (in some calls to `unifyKind`). -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15706> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #14190: Typeable imposes seemingly redundant constraints on polykinded instances
by GHC 26 Nov '18

26 Nov '18

#14190: Typeable imposes seemingly redundant constraints on polykinded instances -------------------------------------+------------------------------------- Reporter: dfeuer | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.4.1 Component: Compiler | Version: 8.2.1 (Type checker) | Keywords: | Operating System: Unknown/Multiple TypeableReflection | Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- To derive `Data` for `Const`, we need {{{#!hs deriving instance (Typeable k, Data a, Typeable (b :: k)) => Data (Const a b) }}} Where's that `Typeable k` constraint come from? It turns out that for reasons I haven't looked into, we can only obtain `Typeable (Const a (b :: k))` if we have `Typeable k`; `(Typeable a, Typeable b)` is insufficient. Is there a reason for that? Annoyingly, we can actually ''get'' that: {{{#!hs weGotThat :: forall k (a :: k). Typeable a :- Typeable k weGotThat = Sub $ withTypeable (typeRepKind (typeRep :: TypeRep a)) Dict }}} But of course that doesn't help us. Could we use `UndecidableSuperClasses` to work around this problem? I think we likely can, although I'm concerned about the performance implications: {{{#!hs class (Typeable a, Typeable' k) => Typeable' (a :: k) instance (Typeable a, Typeable' k) => Typeable' (a :: k) withTypeable' :: forall k (a :: k) r. TypeRep a -> (Typeable' a => r) -> r withTypeable' tr f = withTypeable tr $ withTypeable (typeRepKind (typeRep @a)) f }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14190> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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