June 2014 - ghc-tickets

[GHC] #9166: Missing documentation for the -fwarn-inline-rule-shadowing warning
by GHC 09 Jun '14

09 Jun '14

#9166: Missing documentation for the -fwarn-inline-rule-shadowing warning ------------------------------------+------------------------------------- Reporter: asr | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Documentation | Version: 7.8.2 Keywords: | Operating System: Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+------------------------------------- The {{{-fwarn-inline-rule-shadowing}}} warning, which is on by default, it isn't documented in http://www.haskell.org/ghc/docs/7.8.2/html/users_guide/options- sanity.html. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9166> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9171: Can't match type family with kind polymorphism
by GHC 09 Jun '14

09 Jun '14

#9171: Can't match type family with kind polymorphism ----------------------------+---------------------------------------------- Reporter: | Owner: MikeIzbicki | Status: new Type: bug | Milestone: Priority: normal | Version: 7.8.2 Component: Compiler | Operating System: Unknown/Multiple Keywords: | Type of failure: GHC rejects valid program Architecture: | Test Case: Unknown/Multiple | Blocking: Difficulty: Unknown | Blocked By: | Related Tickets: | ----------------------------+---------------------------------------------- Create a module with the following code: {{{ data Base type family GetParam (p::k1) (t::k2) :: k3 type instance GetParam Base t = t }}} It loads into GHCi just fine. But when we run: {{{ ghci> :t undefined :: GetParam Base (GetParam Base Int) }}} we get an error {{{ <interactive>:1:14: Couldn't match expected type ‘GetParam Base (GetParam Base Int)’ with actual type ‘GetParam Base (GetParam Base Int)’ NB: ‘GetParam’ is a type function, and may not be injective The type variable ‘k0’ is ambiguous In the ambiguity check for: GetParam Base (GetParam Base Int) To defer the ambiguity check to use sites, enable AllowAmbiguousTypes In an expression type signature: GetParam Base (GetParam Base Int) In the expression: undefined :: GetParam Base (GetParam Base Int) }}} If we modify the module by either 1) set `k3` to `k2`, `k1`, or any concrete kind or 2) set `k2` to any concrete kind then the ghci snippet will type check just fine. I assume that this is a mistake, and that the original code should work just fine. If there is some reason, however, why the program would be unsound, then the error message should be made a bit more informative. The claim is that the kind `k0` is ambiguous, but it doesn't appear anywhere in my code! In my full program, it took me a long time to narrow down that this was the source of the problem. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9171> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] Batch modify: #7651, #7919, #8974, #9007, #7028, #7475, #7655, #8975, #5987, #7298, #7411, #7478, #7521, #7567, #7602, #8228, #8736, #8819, #8960, #9012, #3658, #5757, #7143, #7305, #7665, #7695, #8362, #8849, #8951, #8976, #8981, #9003, #9034, #9046, #9100, #8303
by GHC 09 Jun '14

09 Jun '14

Batch modification to #7651, #7919, #8974, #9007, #7028, #7475, #7655, #8975, #5987, #7298, #7411, #7478, #7521, #7567, #7602, #8228, #8736, #8819, #8960, #9012, #3658, #5757, #7143, #7305, #7665, #7695, #8362, #8849, #8951, #8976, #8981, #9003, #9034, #9046, #9100, #8303 by thoughtpolice: milestone to 7.8.4 Comment: Moving to 7.8.4. -- Tickets URL: <http://ghc.haskell.org/trac/ghc/query?id=7651%2C7919%2C8974%2C9007%2C7028%2…> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #7241: GHC-7.6.1 panics on template haskell code
by GHC 09 Jun '14

09 Jun '14

#7241: GHC-7.6.1 panics on template haskell code ---------------------------------------+----------------------------------- Reporter: akamaus | Owner: Yuras Type: bug | Status: closed Priority: normal | Milestone: 7.8.3 Component: Template Haskell | Version: 7.6.1 Resolution: fixed | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time crash | Unknown/Multiple Test Case: | Difficulty: Unknown Blocking: | Blocked By: | Related Tickets: ---------------------------------------+----------------------------------- Changes (by thoughtpolice): * status: merge => closed * resolution: => fixed Comment: Merged. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7241#comment:11> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9050: Panic when compiling cmm file together with -outputdir
by GHC 09 Jun '14

09 Jun '14

#9050: Panic when compiling cmm file together with -outputdir -----------------------------------+--------------------------------------- Reporter: Yuras | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.2 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Compile-time crash Unknown/Multiple | Test Case: Difficulty: Unknown | Blocking: Blocked By: | Related Tickets: | -----------------------------------+--------------------------------------- To reproduce: {{{ $ touch test.cmm $ ghc -c test.cmm -outputdir=build ghc-stage2: panic! (the 'impossible' happened) (GHC version 7.9.20140428 for x86_64-unknown-linux): hscCmmFile: no_mod }}} The panic is declared in `main/HscMain.hs:hscCompileCmmFile` in place of current module name, but forced in `main/CodeOutput.lhs:outputForeignStubs` by `doesFileExist`. It works without `-outputdir` because in that case module name is not used to create path to stub file, see `main/Finder.lhs:mkStubPaths`. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9050> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9080: GHC error on Win 8.1 64bit
by GHC 09 Jun '14

09 Jun '14

#9080: GHC error on Win 8.1 64bit ----------------------------------+--------------------------------------- Reporter: maun | Owner: Type: bug | Status: new Priority: normal | Milestone: 7.8.3 Component: Compiler | Version: 7.8.2 Keywords: | Operating System: Windows Architecture: x86_64 (amd64) | Type of failure: Compile-time crash Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ----------------------------------+--------------------------------------- Hi, i get the following error when building GHCJS: {{{ Loading package conduit-1.1.1 ... linking ... done. Loading package yaml-0.8.8.2 ... ghc.exe: panic! (the 'impossible' happened) (GHC version 7.8.2 for x86_64-unknown-mingw32): loadObj "C:\\Users\\Manuel\\AppData\\Roaming\\cabal\\x86_64 -windows-ghc- 7.8.2\\yaml-0.8.8.2\\HSyaml-0.8.8.2.o": failed Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug ghc.exe: Unknown PEi386 section name `.text.unlikely' (while processing: C:\User s\Manuel\AppData\Roaming\cabal\x86_64-windows- ghc-7.8.2\yaml-0.8.8.2\HSyaml-0.8. 8.2.o) cabal: Error: some packages failed to install: ghcjs-0.1.0 failed during the building phase. The exception was: ExitFailure 1 }}} Also reported this for ghcjs (https://github.com/ghcjs/ghcjs/issues/170) I am not using the haskell plattform, but the 7.8.2 binaries + MinGW and MSYS. I also tried mingw-w64 but this made no difference. I am also using the recent ghcjs cabal branch. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9080> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9155: allocateRegsAndSpill: Cannot read from uninitialized register %vI_s154O (GHC version 7.8.2 for x86_64-unknown-linux)
by GHC 09 Jun '14

09 Jun '14

#9155: allocateRegsAndSpill: Cannot read from uninitialized register %vI_s154O (GHC version 7.8.2 for x86_64-unknown-linux) ------------------------------------+------------------------------------- Reporter: slyfox | 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: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+------------------------------------- When building all world with '''-O2''' I've stuck on wxhaskell (all versions): {{{ [11 of 16] Compiling Graphics.UI.WX.Controls ( src/Graphics/UI/WX/Controls.hs, dist/build/Graphics/UI/WX/Controls.o ) <no location info>: ghc: panic! (the 'impossible' happened) (GHC version 7.8.2 for x86_64-unknown-linux): allocateRegsAndSpill: Cannot read from uninitialized register %vI_s154O }}} I've stripped it down to minimal complete example (but it significantly changed error message) {{{ ghc: panic! (the 'impossible' happened) (GHC version 7.8.2 for x86_64-unknown-linux): RegAlloc.Liveness.computeLivenss SCCs aren't in reverse dependent order bad blockId c1tU [NONREC c1uc: movq $-8,%rbx andq $main:M.AlignLeft{v rb}_closure+1,%rbx addq $8,%rbp jmp *(%rbx), NONREC ... }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9155> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #7828: RebindableSyntax and Arrow
by GHC 09 Jun '14

09 Jun '14

#7828: RebindableSyntax and Arrow ----------------------------------------------+---------------------------- Reporter: AlessandroVermeulen | Owner: Type: bug | jstolarek Priority: normal | Status: new Component: Compiler (Type checker) | Milestone: 7.10.1 Resolution: | Version: 7.6.2 Operating System: Unknown/Multiple | Keywords: Type of failure: GHC rejects valid program | Architecture: Test Case: | Unknown/Multiple Blocking: | Difficulty: Unknown | Blocked By: | Related Tickets: ----------------------------------------------+---------------------------- Comment (by jstolarek): I did some more reading and I finally understand Ross' answers :-) Section 3.2 of John Hughes' "Programming with Arrows" was really helpful in understanding the idea of the stack. But I don't yet understand the implementation and I still have problems reading the comments. I figured a good way of improving my understanding will be implementing a prototype solution outlined in [ticket:7828#comment:9 comment 9]. I wanted to begin by implementing it only for selected language constructs and I got stuck on typechecking !BindStmt in !TcMatches. Currently there is only the monadic !BindStmt. In my prototype I want to distinguish between the monadic and arrow !BindStmt. This means I need to write typechecking for the latter (in !TcMatches). I'm not sure how to do that as I don't know what is the type signature for arrow bind. I tried to deduce that based on the comments in !DsArrows, but I'm not sure if this is a correct approach. Can I once again ask for help in reading the comments? {{{ -- D; xs1 |-a c : () --> t -- D; xs' |-a do { ss } : t' xs2 = xs' - defs(p) -- ----------------------------------- -- D; xs |-a do { p <- c; ss } : t' -- -- ---> premap (\ (xs) -> (((xs1),()),(xs2))) -- (first c >>> arr (\ (p, (xs2)) -> (xs'))) >>> ss }}} I'm totally confused by `(\ (xs) -> (((xs1),()),(xs2)))`. Where do `xs1` and `xs2` come from, if we only bind `xs` as the input to `do { p <- c; ss }`? Also, do I understand correctly that bind expression generated in desugaring of arrow do-notation does not have a source-level equivalent? If so is it even correct to represent it using the !BindStmt constructor? In my prototype I'm ignoring Ross' proposal of the new desugaring. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7828#comment:20> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #95: GHCi :edit command should jump to the the last error
by GHC 08 Jun '14

08 Jun '14

#95: GHCi :edit command should jump to the the last error -------------------------------+------------------------------------------- Reporter: | Owner: lortabac martijnislief | Status: patch Type: feature | Milestone: ⊥ request | Version: None Priority: normal | Keywords: Component: GHCi | Architecture: Unknown/Multiple Resolution: None | Difficulty: Easy (less than 1 hour) Operating System: | Blocked By: Unknown/Multiple | Related Tickets: Type of failure: | None/Unknown | Test Case: | Blocking: | -------------------------------+------------------------------------------- Changes (by nomeata): * owner: => lortabac -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/95#comment:17> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #95: GHCi :edit command should jump to the the last error
by GHC 08 Jun '14

08 Jun '14

#95: GHCi :edit command should jump to the the last error -------------------------------+------------------------------------------- Reporter: | Owner: martijnislief | Status: patch Type: feature | Milestone: ⊥ request | Version: None Priority: normal | Keywords: Component: GHCi | Architecture: Unknown/Multiple Resolution: None | Difficulty: Easy (less than 1 hour) Operating System: | Blocked By: Unknown/Multiple | Related Tickets: Type of failure: | None/Unknown | Test Case: | Blocking: | -------------------------------+------------------------------------------- Comment (by nomeata): Hi lortabac. Thanks for your patch. One thing that is definitely missing is documentation: You should explain this behaviour in the user manual for `:edit`. I would name the field `errors` a bit more self-descriptive. Maybe `lastErrorLocations`? Why do you need `unsafeCoerce`? Can’t you create the `IORef` locally when initializing `GHCiState`, in `interactiveUI`, and also pass it as a first parameter to your `ghciLogAction`? Your `filter` could be more readable a `find` (from `Data.List`). That’s it for now :-) -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/95#comment:16> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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