May 2013 - ghc-tickets

Re: [GHC] #7476: -ddump-minimal-imports confused if first line is an import
by GHC 09 May '13

09 May '13

#7476: -ddump-minimal-imports confused if first line is an import ------------------------------------------+--------------------------------- Reporter: dag | Owner: igloo Type: bug | Status: closed Priority: normal | Milestone: Component: Compiler | Version: Resolution: fixed | Keywords: Os: Unknown/Multiple | Architecture: Unknown/Multiple Failure: None/Unknown | Difficulty: Unknown Testcase: parser/should_compile/T7476 | Blockedby: Blocking: | Related: ------------------------------------------+--------------------------------- Changes (by simonpj): * testcase: => parser/should_compile/T7476 -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7476#comment:5> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #7899: Strange behavior of -ddump-minimal-imports
by GHC 09 May '13

09 May '13

#7899: Strange behavior of -ddump-minimal-imports ----------------------------------------+----------------------------------- Reporter: dsf | Owner: Type: bug | Status: new Priority: normal | Component: Compiler Version: 7.6.2 | Keywords: Os: Linux | Architecture: x86_64 (amd64) Failure: Incorrect result at runtime | Blockedby: Blocking: | Related: ----------------------------------------+----------------------------------- The following two line module: {{{ import System.Exit main = undefined >>= undefined }}} when compiled with {{{ghc -c -ddump-minimal-imports Test.hs}}} produces the following in Main.imports: {{{ import System.Exit ( (>>=), undefined ) }}} Those symbols are not exported by System.Exit. -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7899> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #7900: The impossible happend
by GHC 09 May '13

09 May '13

#7900: The impossible happend -----------------------------+---------------------------------------------- Reporter: dhjdhj | Owner: Type: bug | Status: new Priority: normal | Component: Compiler Version: 7.4.2 | Keywords: Os: Unknown/Multiple | Architecture: Unknown/Multiple Failure: None/Unknown | Blockedby: Blocking: | Related: -----------------------------+---------------------------------------------- ghc: panic! (the 'impossible' happened) (GHC version 7.4.2 for x86_64-apple-darwin): compiler/rename/RnSource.lhs:430:14-81: Irrefutable pattern failed for pattern Data.Maybe.Just (inst_tyvars, _, SrcLoc.L _ cls, _) Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7900> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #5925: Add inline version of newArray#
by GHC 09 May '13

09 May '13

#5925: Add inline version of newArray# ---------------------------------+------------------------------------------ Reporter: tibbe | Owner: Type: feature request | Status: new Priority: normal | Milestone: 7.6.2 Component: Compiler | Version: 7.4.1 Keywords: | Os: Unknown/Multiple Architecture: Unknown/Multiple | Failure: None/Unknown Difficulty: Unknown | Testcase: Blockedby: 4258 | Blocking: Related: | ---------------------------------+------------------------------------------ Comment(by simonpj): It makes a difference whether the size is known at compile time or not. The code that emits the heap check is `entryHeapCheck` in `StgCmmHeap`. Maybe we should talk on Skype. Simon -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/5925#comment:7> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #4230: Template Haskell: less type checking in quotations?
by GHC 09 May '13

09 May '13

#4230: Template Haskell: less type checking in quotations? ---------------------------------+------------------------------------------ Reporter: simonpj | Owner: Type: feature request | Status: new Priority: low | Milestone: 7.6.2 Component: Compiler | Version: 7.6.3 Keywords: | Os: Unknown/Multiple Architecture: Unknown/Multiple | Failure: None/Unknown Difficulty: Unknown | Testcase: Blockedby: | Blocking: 4124, 4125, 4128, 4135, 4170 Related: | ---------------------------------+------------------------------------------ Changes (by simonpj): * cc: gmainlan@… (added) * difficulty: => Unknown Comment: This ticket is more or less subsumed by [http://hackage.haskell.org/trac/ghc/blog/Template%20Haskell%20Proposal my TH blog post proposal]. Geoff Mainland is working on implementing it right now. Simon -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/4230#comment:17> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #4230: Template Haskell: less type checking in quotations?
by GHC 08 May '13

08 May '13

#4230: Template Haskell: less type checking in quotations? ---------------------------------+------------------------------------------ Reporter: simonpj | Owner: Type: feature request | Status: new Priority: low | Milestone: 7.6.2 Component: Compiler | Version: 7.6.3 Keywords: | Os: Unknown/Multiple Architecture: Unknown/Multiple | Failure: None/Unknown Difficulty: | Testcase: Blockedby: | Blocking: 4124, 4125, 4128, 4135, 4170 Related: | ---------------------------------+------------------------------------------ Changes (by carter): * version: 6.12.3 => 7.6.3 Comment: One use case / example /motivation I encountered this week is the following: To make the LLVM-Base library work with cabal versions 1.16 and cabal head, I wanted to write the following code {{{ --- what i'd like to write, but can't because template haskell rejecting the branch that has the wrong api version extractCLBI x= $(if cabalVersion >= Version [1,17,0] [] then [| getComponentLocalBuildInfo 'x CLibName |] else [| let LocalBuildInfo { libraryConfig = Just clbi } = 'x in clbi |] ) }}} {{{ --- horrible hack to support cabal versions both above and below 1.17 extractCLBI x= $(if cabalVersion >= Version [1,17,0] [] then appE (appE ( varE $ mkName "getComponentLocalBuildInfo") ( varE 'x) ) (conE ( mkName "CLibName")) else letE [valD (recP (mkName "LocalBuildInfo" ) [fieldPat (mkName "libraryConfig") (conP (mkName "Just") [varP $ mkName "clbi"] ) ] ) (normalB $ varE 'x) [] ] (varE $ mkName "clbi") ) }}} In this case, I need to explicitly write out the AST so that template haskell doesn't barf. Would one near term solution be to 1. do the harmonization between haskell-src-exts and TH (as suggested / discussed elsewhere) 2. provide untypedExp, Dec, etc quasiquoters ? this would be a pretty happy balance of allowing both the stronger and weaker typings, and might be a reasonable first step towards actually working on MetaHaskell -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/4230#comment:16> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #5925: Add inline version of newArray#
by GHC 08 May '13

08 May '13

#5925: Add inline version of newArray# ---------------------------------+------------------------------------------ Reporter: tibbe | Owner: Type: feature request | Status: new Priority: normal | Milestone: 7.6.2 Component: Compiler | Version: 7.4.1 Keywords: | Os: Unknown/Multiple Architecture: Unknown/Multiple | Failure: None/Unknown Difficulty: Unknown | Testcase: Blockedby: 4258 | Blocking: Related: | ---------------------------------+------------------------------------------ Comment(by tibbe): I'm interested in getting something working first (i.e. a version of `newArray#` that allocates inline). We can then see what we can do about merging heap checks. Which code tackles merging these checks? The optimization seems similar to floating plus constant folding/conditional merging to me. -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/5925#comment:6> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #4385: Type-level natural numbers
by GHC 08 May '13

08 May '13

#4385: Type-level natural numbers ----------------------------------------+----------------------------------- Reporter: diatchki | Owner: diatchki Type: feature request | Status: new Priority: normal | Milestone: 7.6.2 Component: Compiler (Type checker) | Version: Keywords: | Os: Unknown/Multiple Architecture: Unknown/Multiple | Failure: None/Unknown Difficulty: | Testcase: Blockedby: | Blocking: Related: | ----------------------------------------+----------------------------------- Comment(by diatchki): Thanks, I'll take a look and try to improve the solver. Unfortunately, I don't think that there's an easy way to work around this in the polymorphic case. If you could instantiate the `n`s somehow, it'd get solved, but I know that's not always an option. -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/4385#comment:59> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #4385: Type-level natural numbers
by GHC 08 May '13

08 May '13

#4385: Type-level natural numbers ----------------------------------------+----------------------------------- Reporter: diatchki | Owner: diatchki Type: feature request | Status: new Priority: normal | Milestone: 7.6.2 Component: Compiler (Type checker) | Version: Keywords: | Os: Unknown/Multiple Architecture: Unknown/Multiple | Failure: None/Unknown Difficulty: | Testcase: Blockedby: | Blocking: Related: | ----------------------------------------+----------------------------------- Comment(by maltem): I'm trying out the type-nats branch and the wiki says to complain when the solver cannot solve something, so here we go: {{{ Bug.hs:22:29: Could not deduce ((2 * n) ~ ((2 * n1) + 2)) from the context (n ~ (n1 + 1)) }}} The code is attached. I'd welcome a hint how I can work around the error (the wiki mentions that this should typically be possible, but I don't understand how). -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/4385#comment:58> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #7896: Type constructor is accepted as context
by GHC 08 May '13

08 May '13

#7896: Type constructor is accepted as context ----------------------------------------+----------------------------------- Reporter: stefan | Owner: Type: bug | Status: new Priority: normal | Component: Compiler (Type checker) Version: 7.6.3 | Keywords: Os: Unknown/Multiple | Architecture: Unknown/Multiple Failure: GHC accepts invalid program | Blockedby: Blocking: | Related: ----------------------------------------+----------------------------------- Consider the following program: {{{ f :: Int => () -> () f _ = id }}} It is accepted by the compiler, even though we are using a type constructor rather than a class assertion in a type context. -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7896> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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