November 2013 - ghc-tickets

[GHC] #8519: Make -XTemplateHaskell an error in a stage-1 compiler
by GHC 12 Nov '13

12 Nov '13

#8519: Make -XTemplateHaskell an error in a stage-1 compiler ------------------------------------+------------------------------------- Reporter: simonpj | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.6.3 Keywords: | Operating System: Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+------------------------------------- If you use the language extension `-XTemplateHaskell` in a stage-1 compiler, it's guaranteed not to work. This patch makes it an error to do so. The error is suppressed in `MkDepend` mode (i.e. `ghc -M`) because that ''does'' work; the TH flag is not consulted. Moreover it is used by GHC's build system itself: for some reason we use the stage-1 compiler to do build the `.depend` files for DPH, even though DPH is only built with stage2. This is an infelicity, but Ian writes "It's due to the [wiki:Building/Architecture/Idiom/PhaseOrdering#GHCsphases build system phases]: stage2 doesn't exist during the phase in which DPH is configured. Changing it to use stage 2 would probably mean adding another phase for things that need to be configured by stage 2. This might mean slower builds due to loss of parallelism, I'm not sure. This change isn't mission critical; it could be a warning instead. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8519> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #4268: Warning for ANN pragmas when GHCi is not supported
by GHC 12 Nov '13

12 Nov '13

#4268: Warning for ANN pragmas when GHCi is not supported -------------------------------+------------------------------------------- Reporter: simonmar | Owner: Type: bug | Status: closed Priority: high | Milestone: 7.8.1 Component: Compiler | Version: 7.0.4 Resolution: fixed | Keywords: Operating System: | Architecture: Unknown/Multiple Unknown/Multiple | Difficulty: Easy (less than 1 hour) Type of failure: Other | Blocked By: Test Case: | Related Tickets: #8312, #5105 Blocking: | -------------------------------+------------------------------------------- Changes (by simonpj): * status: new => closed * resolution: => fixed Comment: I don't know how to make a test that runs the stage-1 compiler and it's not that important, so I'm closing without a regression test. Simon -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/4268#comment:17> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #6068: Panic in GHCi when using functional dependencies and promoted kinds
by GHC 12 Nov '13

12 Nov '13

#6068: Panic in GHCi when using functional dependencies and promoted kinds -------------------------------------+------------------------------------ Reporter: goldfire | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: GHCi | Version: 7.5 Resolution: | Keywords: PolyKinds Operating System: Unknown/Multiple | Architecture: Unknown/Multiple Type of failure: GHCi crash | Difficulty: Unknown Test Case: polykinds/T6068 | Blocked By: Blocking: | Related Tickets: -------------------------------------+------------------------------------ Comment (by simonpj): I think there's a real bug. I'm looking at it -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/6068#comment:6> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8507: ConstraintKinds TH regression from 7.6 -> 7.7
by GHC 12 Nov '13

12 Nov '13

#8507: ConstraintKinds TH regression from 7.6 -> 7.7 ----------------------------+---------------------------------------------- Reporter: errge | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Template | Version: 7.7 Haskell | Operating System: Unknown/Multiple Keywords: | Type of failure: GHC rejects valid program Architecture: | Test Case: Unknown/Multiple | Blocking: Difficulty: Unknown | Blocked By: | Related Tickets: | ----------------------------+---------------------------------------------- {{{ {-# LANGUAGE TemplateHaskell #-} {-# LANGUAGE ConstraintKinds #-} module ConstraintKindUser where -- type Stringy a = (Read a, Show a) $([d|type Stringy a = (Read a, Show a) |]) }}} Results in this error message: {{{ ConstraintKindUser.hs:7:3: The first argument of a tuple should have kind ‛*’, but ‛Read a_a2ZZ’ has kind ‛Constraint’ In the type ‛(Read a_a2ZZ, Show a_a2ZZ)’ In the type declaration for ‛Stringy’ }}} This is a regression compared to 7.6.3. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8507> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #4268: Warning for ANN pragmas when GHCi is not supported
by GHC 12 Nov '13

12 Nov '13

#4268: Warning for ANN pragmas when GHCi is not supported -------------------------------+------------------------------------------- Reporter: simonmar | Owner: Type: bug | Status: new Priority: high | Milestone: 7.8.1 Component: Compiler | Version: 7.0.4 Resolution: | Keywords: Operating System: | Architecture: Unknown/Multiple Unknown/Multiple | Difficulty: Easy (less than 1 hour) Type of failure: Other | Blocked By: Test Case: | Related Tickets: #8312, #5105 Blocking: | -------------------------------+------------------------------------------- Comment (by Simon Peyton Jones <simonpj@…>): In [changeset:"6c1aba4ff27371fddfc0dce5f9256c97edf16eea/ghc"]: {{{ #!CommitTicketReference repository="ghc" revision="6c1aba4ff27371fddfc0dce5f9256c97edf16eea" Warn if you use ANN annotations with a stage-1 compiler (Trac #4268) This makes us give a civilised warning when we hit an {-# ANN f foo #-} pragma in a stage-1 compiler. We decided that, since it's a pragma, it does not need a language extension flag to enable it. }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/4268#comment:16> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #5996: fix for CSE
by GHC 12 Nov '13

12 Nov '13

#5996: fix for CSE --------------------------------------------+------------------------------ Reporter: michalt | Owner: simonpj Type: bug | Status: patch Priority: normal | Milestone: 7.8.1 Component: Compiler | Version: 7.5 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Runtime performance bug | Unknown/Multiple Test Case: | Difficulty: Unknown Blocking: | Blocked By: | Related Tickets: --------------------------------------------+------------------------------ Comment (by Simon Peyton Jones <simonpj@…>): In [changeset:"0001d161f7f6a6f7392eb2a3229f6204c3423450/ghc"]: {{{ #!CommitTicketReference repository="ghc" revision="0001d161f7f6a6f7392eb2a3229f6204c3423450" Fix egregious omission in CSE (Trac #5996) This patch fixes a bad omission in CSE, thanks to 'michaelt' for spotting it, and correctly identifying the fix (in cseRhs). The trouble was with x1 = C a b x2 = C x1 b y1 = C a b y2 = C y1 b we were not commoning up y2=x2, because we failed to substitute y1:=x1, so y2's RHS looked different to x2's I also refactoring, so taht the cs_map in a CSEnv map is cs_map :: CoreMap (OutExpr, Id) instead of cs_map :: CoreMap (OutExpr, OutExpr) Much nicer! This doesn't make much difference to allocation, but it gives a surprisingly big benefit to binary size. -------------------------------------------------------------------------------- Program Size Allocs Runtime Elapsed TotalMem -------------------------------------------------------------------------------- ansi -1.7% -0.8% 0.00 0.00 +0.0% bspt -1.6% -1.5% 0.01 0.01 +0.0% cacheprof -1.8% -0.2% +1.6% +1.9% +2.7% fft -1.4% -1.3% 0.06 0.06 +11.1% ida -1.4% -1.0% 0.12 0.12 +0.0% rfib -1.4% -0.1% 0.03 0.03 +0.0% scs -1.6% -0.1% +1.5% +1.5% +0.0% spectral-norm -1.3% -0.1% -0.2% -0.2% +0.0% tak -1.4% -0.1% 0.02 0.02 +0.0% veritas -1.4% -0.1% 0.00 0.00 +0.0% -------------------------------------------------------------------------------- Min -2.5% -1.5% -11.8% -11.8% -8.0% Max -1.0% +0.0% +2.7% +2.5% +11.1% Geometric Mean -1.3% -0.1% -2.6% -2.6% +0.0% }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/5996#comment:9> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #7229: Detecting if a process was killed by a signal is impossible
by GHC 12 Nov '13

12 Nov '13

#7229: Detecting if a process was killed by a signal is impossible --------------------------------------+------------------------------------ Reporter: benmachine | Owner: Type: bug | Status: new Priority: high | Milestone: 7.8.1 Component: libraries/process | Version: Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Unknown/Multiple Type of failure: None/Unknown | Difficulty: Unknown Test Case: | Blocked By: Blocking: | Related Tickets: --------------------------------------+------------------------------------ Comment (by duncan): Here's my updated patch. '''Totally untested''' {{{#!diff diff --git a/GHC/TopHandler.lhs b/GHC/TopHandler.lhs index 9e4bc07..8953334 100644 --- a/GHC/TopHandler.lhs +++ b/GHC/TopHandler.lhs @@ -180,7 +180,28 @@ flushStdHandles = do -- we have to use unsafeCoerce# to get the 'IO a' result type, since the -- compiler doesn't let us declare that as the result type of a foreign export. safeExit :: Int -> IO a +#ifdef mingw32_HOST_OS safeExit r = unsafeCoerce# (shutdownHaskellAndExit $ fromIntegral r) +#else +-- On Unix we use an encoding for the ExitCode: +-- Bits: 0-7 (mask 0x00ff) normal exit code +-- Bits: 8-14 (mask 0x7f00) exit by signal +-- Bits: 15 (mask 0x8000) core dump (allowed with signal but ignored) +-- A normal exit, and exit by signal are mutually exclusive. +-- For any invalid encoding we just use a replacement (0xff). +safeExit r + | sig /= 0 && code == 0 && other == 0 {-any cdump-} + = unsafeCoerce# (shutdownHaskellAndSignal $ fromIntegral sig) + | sig == 0 {-any code-} && other == 0 && cdump == 0 + = unsafeCoerce# (shutdownHaskellAndExit $ fromIntegral code) + | otherwise + = unsafeCoerce# (shutdownHaskellAndExit 0xff) + where + sig = (r .&. 0x7f00) `shiftR` 8 + cdump = r .&. 0x8000 + code = r .&. 0x00ff + other = r .&. (complement 0xffff) +#endif exitInterrupted :: IO a exitInterrupted = }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7229#comment:35> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #6068: Panic in GHCi when using functional dependencies and promoted kinds
by GHC 12 Nov '13

12 Nov '13

#6068: Panic in GHCi when using functional dependencies and promoted kinds -------------------------------------+------------------------------------ Reporter: goldfire | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: GHCi | Version: 7.5 Resolution: | Keywords: PolyKinds Operating System: Unknown/Multiple | Architecture: Unknown/Multiple Type of failure: GHCi crash | Difficulty: Unknown Test Case: polykinds/T6068 | Blocked By: Blocking: | Related Tickets: -------------------------------------+------------------------------------ Comment (by nomeata): Confirmed, the test fails with `-DDEBUG`. So is the debugging information wrong, or is there a real bug? -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/6068#comment:5> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #6068: Panic in GHCi when using functional dependencies and promoted kinds
by GHC 12 Nov '13

12 Nov '13

#6068: Panic in GHCi when using functional dependencies and promoted kinds -------------------------------------+------------------------------------ Reporter: goldfire | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: GHCi | Version: 7.5 Resolution: | Keywords: PolyKinds Operating System: Unknown/Multiple | Architecture: Unknown/Multiple Type of failure: GHCi crash | Difficulty: Unknown Test Case: polykinds/T6068 | Blocked By: Blocking: | Related Tickets: -------------------------------------+------------------------------------ Comment (by nomeata): With completely fresh check-outs, it does not happen using validate, but it does happen with `BuildFlavour = devel2`. So likely it is related to `-DDebug` in `GhcStage2HcOpts`. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/6068#comment:4> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #6068: Panic in GHCi when using functional dependencies and promoted kinds
by GHC 12 Nov '13

12 Nov '13

#6068: Panic in GHCi when using functional dependencies and promoted kinds -------------------------------------+------------------------------------ Reporter: goldfire | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: GHCi | Version: 7.5 Resolution: | Keywords: PolyKinds Operating System: Unknown/Multiple | Architecture: Unknown/Multiple Type of failure: GHCi crash | Difficulty: Unknown Test Case: polykinds/T6068 | Blocked By: Blocking: | Related Tickets: -------------------------------------+------------------------------------ Changes (by nomeata): * cc: hvr (added) * status: closed => new * resolution: fixed => Comment: In a fresh checkout (95216e8fa0ecb98189dce29f0b89b3b0f8d439c6, `distclean`’ed and built), I get: {{{ =====> T6068(ghci) 2026 of 3814 [0, 0, 0] cd ./polykinds && HC='/home/jojo/build/haskell/ghc/inplace/bin/ghc-stage2' HC_OPTS='-dcore-lint -dcmm-lint -dno-debug-output -no-user-package-db -rtsopts -fno-ghci-history ' '/home/jojo/build/haskell/ghc/inplace/bin /ghc-stage2' --interactive -v0 -ignore-dot-ghci -dcore-lint -dcmm-lint -dno-debug-output -no-user-package-db -rtsopts -fno-ghci-history <T6068.script >T6068.run.stdout 2>T6068.run.stderr Actual stderr output differs from expected: --- /dev/null 2013-11-12 10:20:30.826690103 +0100 +++ ./polykinds/T6068.run.stderr 2013-11-12 10:39:54.333361005 +0100 @@ -0,0 +1,9 @@ +ghc-stage2: panic! (the 'impossible' happened) + (GHC version 7.7.20131108 for x86_64-unknown-linux): + ASSERT failed! + file compiler/typecheck/TcMType.lhs line 809 + [D] _ :: mp{tv aEn} [tau[0]] + ghc-prim:GHC.Types.~{(w) tc 31Q} kp_aEi{tv} [tau[0]] (CIrredEvCan) + +Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug + Actual stdout output differs from expected: --- ./polykinds/T6068.stdout 2013-10-05 15:18:57.118579683 +0200 +++ ./polykinds/T6068.run.stdout 2013-11-12 10:39:54.193361010 +0100 @@ -1 +0,0 @@ -exists Nothing :: Floop a mp => Existential mp *** unexpected failure for T6068(ghci) }}} Strangely, on [https://s3.amazonaws.com/archive.travis- ci.org/jobs/13835382/log.txt travis] it succeeded. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/6068#comment:3> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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