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Re: [GHC] #95: GHCi :edit command should jump to the the last error
by GHC 09 Jun '14

09 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: | -------------------------------+------------------------------------------- Comment (by lortabac): I followed your suggestions and I also fixed a small mistake. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/95#comment:18> 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 ross): Replying to [comment:20 jstolarek]: > 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 }`? They are subsets of `xs`: `xs1` is the variables used by `c`, while `xs2` is the variables used by `ss` but not bound in `p`. So the command 'c' gets local environment `xs1` and stack `()`. The translations of statements are arrows that take an environment (here `xs2`) as input. > 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. I don't understand that question - I don't see a bind expression in the generated code. Do you mean the `BindStmt` emitted by the type checker? No, that wouldn't correspond to something one could write in the command sublanguage. Part of the motivation for my proposal is that the desugaring of do notation would have a source-level equivalent, albeit still in the command sublanguage, but it could be checked using the existing rules for commands. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7828#comment:21> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9127: Don't warn about pattern-bindings of the form `let !_ = rhs`
by GHC 09 Jun '14

09 Jun '14

#9127: Don't warn about pattern-bindings of the form `let !_ = rhs` ------------------------------------+------------------------------------- Reporter: refold | 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: | ------------------------------------+------------------------------------- With GHC 7.8.2, code like {{{ let !_ = rqPostParams rq let !_ = rqParams rq }}} triggers the following warnings: {{{ src/Snap/Internal/Test/RequestBuilder.hs:150:13: Warning: This pattern-binding binds no variables: !_ = rqPostParams rq src/Snap/Internal/Test/RequestBuilder.hs:151:13: Warning: This pattern-binding binds no variables: !_ = rqParams rq }}} I think that `let !_ = rhs` shouldn't trigger a warning, just like `let _ = rhs` doesn't. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9127> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8753: Import constructor but not the data type
by GHC 09 Jun '14

09 Jun '14

#8753: Import constructor but not the data type ------------------------------------+------------------------------------- Reporter: andreas.abel | Owner: Type: feature request | 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: | ------------------------------------+------------------------------------- How do I import a constructor but not its data type? The constructor might have the name of a data type which I do not want to bring into scope. Use case: Library (A) defines a parametrized data type (D a) which I want to use in my code (B) in instantiated form (D Int) but with the same name (D). I want to pattern match against inhabitants of type D, so I need the constructor(s) in scope. Here is how it could look like if import lists let me specify whether I want to import a type or a constructor with name "D". module A where data D a = D a module B where import A (constructor D) import qualified A D = A.D Int f :: D -> Int f (D x) = x Haskell has different name spaces for type and constructors, but does not let the user talk about these name spaces where it matters, namely in import/export lists. At least I found no documentation instructing me how to do this. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8753> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[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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