October 2016 - ghc-tickets

[GHC] #12667: Compiling haskell-stack crashes the compiler
by GHC 05 Oct '16

05 Oct '16

#12667: Compiling haskell-stack crashes the compiler -------------------------------------+------------------------------------- Reporter: hudon | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 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: -------------------------------------+------------------------------------- When upgrading haskell-stack using brew, I get: {{{ ==> Upgrading haskell-stack ==> Downloading https://github.com/commercialhaskell/stack/releases/download/v1.1.2/stack-1… Already downloaded: /Users/hudon/Library/Caches/Homebrew/haskell- stack-1.1.2.tar.gz ==> cabal sandbox init ==> cabal update ==> cabal install --jobs=8 --max-backjumps=100000 Last 15 lines from /Users/hudon/Library/Logs/Homebrew/haskell- stack/03.cabal: [ 1 of 87] Compiling Stack.FileWatch ( src/Stack/FileWatch.hs, dist/dist- sandbox-7d57129e/build/Stack/FileWatch.o ) [ 2 of 87] Compiling System.Process.PagerEditor ( src/System/Process/PagerEditor.hs, dist/dist-sandbox- 7d57129e/build/System/Process/PagerEditor.o ) [ 3 of 87] Compiling System.Process.Log ( src/System/Process/Log.hs, dist /dist-sandbox-7d57129e/build/System/Process/Log.o ) [ 4 of 87] Compiling System.Process.Read ( src/System/Process/Read.hs, dist/dist-sandbox-7d57129e/build/System/Process/Read.o ) ghc: panic! (the 'impossible' happened) (GHC version 8.0.1 for x86_64-apple-darwin): Loading temp shared object failed: dlopen(/var/folders/lc/jm4g8s190gl8977h7tz9j6tc0000gn/T/ghc18925_0/libghc_44.dylib, 5): no suitable image found. Did find: /var/folders/lc/jm4g8s190gl8977h7tz9j6tc0000gn/T/ghc18925_0/libghc_44.dylib: malformed mach-o: load commands size (40304) > 32768 Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} {{{ $ ghc --version The Glorious Glasgow Haskell Compilation System, version 8.0.1 }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12667> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #12656: ghci floats out constant despite -fno-cse, resulting in very unintuitive behaviour
by GHC 04 Oct '16

04 Oct '16

#12656: ghci floats out constant despite -fno-cse, resulting in very unintuitive behaviour -------------------------------------+------------------------------------- Reporter: nh2 | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Incorrect result Unknown/Multiple | at runtime Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- Consider this program using `Data.Vector.unsafeThaw` and `-fno-cse`: {{{ {-# OPTIONS_GHC -fno-cse #-} import qualified Data.Vector as V import qualified Data.Vector.Mutable as VM main :: IO () main = do foo 100000 foo 100000 foo :: Int -> IO () foo n = do indexVector <- V.unsafeThaw $ V.generate n id x <- VM.read indexVector 5 VM.write indexVector 5 (x * x) print x -- In GHCI, we get: -- -- > :set -fno-cse -- -- > foo 100000 -- 5 -- > foo 100000 -- 5 -- -- > let f = foo 100000 in f >> f -- 5 -- 25 }}} I would expect that {{{ > let f = foo 100000 in f >> f 5 5 }}} Shouldn't `-fno-cse` fix this? (Note: With `ghc` instead of `ghci`, we don't observe this behaviour.) -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12656> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #12659: Unactionable core lint warning due to floating out
by GHC 04 Oct '16

04 Oct '16

#12659: Unactionable core lint warning due to floating out -------------------------------------+------------------------------------- Reporter: mpickering | Owner: Type: bug | Status: new Priority: low | Milestone: Component: Compiler | Version: 8.0.1 Keywords: newcomer | 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 was looking through the build log to try and make it a bit less noisy by removing some warnings. There were quite a lot of core lint warnings which complain about INLINE progams on loop breakers. However, sometimes these bindings are not marked INLINE at the source level but by GHC itself. {{{ cmmDebugLink :: [Label] -> [DebugBlock] -> [DebugBlock] cmmDebugLink labels blocks = map link blocks where blockPos :: LabelMap Int blockPos = mapFromList $ flip zip [0..] labels link block = block { dblPosition = mapLookup (dblLabel block) blockPos , dblBlocks = map link (dblBlocks block) } }}} For example, in this function, `link` gets floated out to the top level and then marked as `INLINE` even though it is self-recursive. This causes the following warning: {{{ *** Core Lint warnings : in result of CorePrep *** 5170 <no location info>: warning: 5171 [RHS of link_slxp :: DebugBlock -> DebugBlock] 5172 INLINE binder is (non-rule) loop breaker: link_slxp 5173 }}} But because it's generated by the compiler, there isn't a sensible way to suppress the warning. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12659> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #6132: Can't use both shebang line and #ifdef declarations in the same file.
by GHC 04 Oct '16

04 Oct '16

#6132: Can't use both shebang line and #ifdef declarations in the same file. -------------------------------------+------------------------------------- Reporter: gfxmonk | Owner: Type: bug | Status: new Priority: normal | Milestone: 8.0.2 Component: Compiler | Version: 7.0.4 (Parser) | Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: GHC rejects | Unknown/Multiple valid program | Test Case: runghc/T6132 Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by bgamari): Thanks Reid! Yet another reason to move to hpp, I suppose. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/6132#comment:13> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #12637: ghc-pkg: Allow unregistering multiple packages in one call
by GHC 04 Oct '16

04 Oct '16

#12637: ghc-pkg: Allow unregistering multiple packages in one call -------------------------------------+------------------------------------- Reporter: nh2 | Owner: Type: feature | Status: new request | Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 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: -------------------------------------+------------------------------------- This can save lots of time when the cost to invoke a single GHC command is high, for example through docker. An example user of this would be `stack build`, which will unregister all relevant packages if e.g. `--extra-lib-dirs` has changed. Currently it has to do that through multiple `ghc-pkg unregister` operations, which can take about 2 seconds per call when done through a docker image. If we could unregister multiple packages at once, such use cases would have to pay the 2 seconds penalty only once. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12637> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #6132: Can't use both shebang line and #ifdef declarations in the same file.
by GHC 04 Oct '16

04 Oct '16

#6132: Can't use both shebang line and #ifdef declarations in the same file. -------------------------------------+------------------------------------- Reporter: gfxmonk | Owner: Type: bug | Status: new Priority: normal | Milestone: 8.0.2 Component: Compiler | Version: 7.0.4 (Parser) | Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: GHC rejects | Unknown/Multiple valid program | Test Case: runghc/T6132 Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by rwbarton): It's because clang's CPP inserts a space before the `#` and then GHC no longer recognizes it as a shebang line. See #10044 for a related clang whitespace oddity. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/6132#comment:12> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10163: Export typeRepKinds in Data.Typeable
by GHC 04 Oct '16

04 Oct '16

#10163: Export typeRepKinds in Data.Typeable -------------------------------------+------------------------------------- Reporter: | Owner: RyanGlScott | Status: new Type: feature | Milestone: request | Version: 7.10.1-rc3 Priority: normal | Operating System: Unknown/Multiple Component: | Type of failure: Other libraries/base | Blocked By: Keywords: | Related Tickets: Architecture: | Unknown/Multiple | Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- Now that {{{TypeRep}}} has a {{{[KindRep]}}} field internally, {{{Data.Typeable}}} should export {{{typeRepKinds}}} (alongside {{{typeRepTyCon}}} and {{{typeRepArgs}}}, which are currently exported) to allow users to access it. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10163> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11054: GHC on Windows could not use more than 64 logical processors
by GHC 03 Oct '16

03 Oct '16

#11054: GHC on Windows could not use more than 64 logical processors -------------------------------------+------------------------------------- Reporter: varosi | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Runtime | Version: 7.10.2 System | Keywords: | Operating System: Windows Architecture: x86_64 | Type of failure: Runtime (amd64) | performance bug Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- I found that GHC runtime does not take advantage of processor groups under Windows. So it cannot use more than 64 logical processors (2x 18 core physical + HT). This is Reddit thread about: https://www.reddit.com/r/haskell/comments/3q1r0o/ghc_on_numa_72_core_2_proc… MSDN link https://msdn.microsoft.com/en- us/library/windows/desktop/dd405503(v=vs.85).aspx -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11054> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #8040: installed include/HsVersions.h wants to #include "../includes/ghcautoconf.h"
by GHC 02 Oct '16

02 Oct '16

#8040: installed include/HsVersions.h wants to #include "../includes/ghcautoconf.h" -------------------------------------+------------------------------------- Reporter: hvr | Owner: Type: bug | Status: closed Priority: normal | Milestone: 8.2.1 Component: Build System | Version: 7.6.3 Resolution: fixed | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D2530 Wiki Page: | -------------------------------------+------------------------------------- Comment (by Ben Gamari <ben@…>): In [changeset:"e9104d46eab0a2fbf7af9a299da3763bcf39f148/ghc" e9104d46/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="e9104d46eab0a2fbf7af9a299da3763bcf39f148" DynFlags: Fix absolute import path to generated header Test Plan: Validate Reviewers: austin, snowleopard Reviewed By: snowleopard Subscribers: thomie Differential Revision: https://phabricator.haskell.org/D2559 GHC Trac Issues: #8040. }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8040#comment:7> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #6132: Can't use both shebang line and #ifdef declarations in the same file.
by GHC 02 Oct '16

02 Oct '16

#6132: Can't use both shebang line and #ifdef declarations in the same file. -------------------------------------+------------------------------------- Reporter: gfxmonk | Owner: Type: bug | Status: new Priority: normal | Milestone: 8.0.2 Component: Compiler | Version: 7.0.4 (Parser) | Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: GHC rejects | Unknown/Multiple valid program | Test Case: runghc/T6132 Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by Ben Gamari <ben@…>): In [changeset:"3630ad355a5b7be0240d3071bb662fe710909cca/ghc" 3630ad3/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="3630ad355a5b7be0240d3071bb662fe710909cca" Mark #6132 as broken on OS X It currently fails with, =====> T6132(normal) 1 of 1 [0, 0, 0] cd "./runghc/T6132.run" && "/Users/bgamari/ghc/inplace/test spaces/ghc-stage2" -c T6132.hs -dcore-lint -dcmm-lint -no-user-package-db -rtsopts -fno-warn-missed-specialisations -fshow-warning-groups -dno-debug-output Compile failed (exit code 1) errors were: T6132.hs:1:2: error: parse error on input ‘#!/’ *** unexpected failure for T6132(normal) }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/6132#comment:11> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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