December 2015 - ghc-tickets

[GHC] #8245: ghc-pkg list prints packages in non-alphabetical order
by GHC 07 Dec '15

07 Dec '15

#8245: ghc-pkg list prints packages in non-alphabetical order ------------------------------------+------------------------------------- Reporter: nh2 | 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: | ------------------------------------+------------------------------------- Instead, it prints the ones with the smallest version first. That does not make much sense. I will attach a patch. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8245> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10908: -fwarn-missing-exported-sigs doesn't respect qualified names
by GHC 07 Dec '15

07 Dec '15

#10908: -fwarn-missing-exported-sigs doesn't respect qualified names -------------------------------------+------------------------------------- Reporter: goldfire | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.2 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Incorrect Unknown/Multiple | warning at compile-time Test Case: | Blocked By: Blocking: | Related Tickets: Differential Revisions: | -------------------------------------+------------------------------------- Trying to help @mpickering with Phab:D1258, I looked at the code in `tcRnSrcDecls` and was surprised to see that exports are renamed after this function is complete. This didn't make any sense to me. And, indeed, it's wrong, witness by this example: {{{ {-# OPTIONS_GHC -fwarn-missing-exported-sigs #-} module Bug (Data.List.intercalate, x) where import qualified Data.List intercalate = True x :: Bool x = intercalate }}} This produces {{{ Bug.hs:7:1: Warning: Top-level binding with no type signature: intercalate :: Bool }}} This warning should not be emitted. I'm not all that concerned about this scenario biting in the wild, but it suggests that refactoring this code is a good thing, and not something Phab:D1258 should take pains to avoid. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10908> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11028: Refactor ConDecl
by GHC 07 Dec '15

07 Dec '15

#11028: Refactor ConDecl -------------------------------------+------------------------------------- Reporter: simonpj | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.2 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: -------------------------------------+------------------------------------- The `ConDecl` type in `HsDecls` is an uneasy compromise. For the most part, `HsSyn` directly reflects the syntax written by the programmer; and that gives just the right "pegs" on which to hang Alan's [wiki:ApiAnnotations API annotations]. But `ConDecl` doesn't properly reflect the syntax of Haskell-98 and GADT-style data type declarations. To be concrete, here's a draft new data type {{{ data ConDecl name | ConDeclGADT { con_names :: [Located name] , con_type :: LHsSigType name -- The type after the ‘::’ , con_doc :: Maybe LHsDocString , con_old_rec :: Bool } | ConDeclH98 { con_name :: Located name , con_implict :: HsImplicitBndrs () -- ^ Implicit binders, added by renamer , con_qvars :: Maybe [LHsTyVarBndr name] -- User-written foralls (if any) , con_cxt :: Maybe (LHsContext name) -- ^ User-written context (if any) , con_details :: HsConDeclDetails name -- ^ Arguments , con_doc :: Maybe LHsDocString -- ^ A possible Haddock comment. } deriving (Typeable) }}} Note that * For GADTs, just keep a type. That's what the user writes. (NB: `HsType` can represent records on the LHS of an arrow: `{ x:Int,y:Bool } -> T` * `con_qvars` and `con_cxt` are both `Maybe` because they are both optional (the `forall` and the context of an existential data type) * The `con_old_rec` is a warning thing for GADTs (see current source code) This ticket is just to track the thought and invite feedback. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11028> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9015: A documented way to differentiate between statements, declarations, imports, etc.
by GHC 07 Dec '15

07 Dec '15

#9015: A documented way to differentiate between statements, declarations, imports, etc. -------------------------------------+------------------------------------- Reporter: splinterofchaos | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: GHC API | Version: 7.8.2 Keywords: | Operating System: Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: Documentation Difficulty: Moderate (less | bug than a day) | Test Case: Blocked By: | Blocking: Related Tickets: | -------------------------------------+------------------------------------- I'm working on a little REPL and the GHC API seems to supply two functions for evaluating one line, without compiling and evaluating into an `HValue`, which doesn't seem to have an `Outputable` instace: `runStmt` and `runDecls`. As it turns out, I need slightly different code to run on declarations verses statements, so this makes sense, but given a random string from the user, how can I tell the difference? I don't see anything in the documentation about this. I took a look at ghci's source (https://github.com/ghc/ghc/blob/a6f2c852d49313fa8acea2deb3741ab86c6ef995/gh…] and it looks like they just peek at the first word of the input, and that may be correct and sufficient, but impossible to verify without looking at Haskell's grammar. But even if I did verify it, that doesn't make explicit the difference between what `runDecls` and `runStmt` will accept. For a contrived example, consider if GHC implemented a feature that allowed for a new type of decl. It might be enabled by a language extension which means that testing whether a string is a statement or declaration cannot be done purely as we have to check the dynflags. Furthermore, the client may not be aware of the extension and thus send the input to `runStmt` instead. It would seem to me that requiring the user to manually parse the input violates separation of concerns since truly GHC knows best what source GHC will accept. The user should not have to examine the input except for if they need to modify or interpret it as something other than Haskell source code. The GHC API should either document an example function for differentiating declarations from statements (and even import statements), supply one itself, or supply several along the lines of `isDecl, isStmt, isImport :: String -> Bool`. This would improve ease-of-use by making client code more obvious and correct. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9015> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #6119: complain when ghc-pkg doesn't find any matching packages in a given database
by GHC 07 Dec '15

07 Dec '15

#6119: complain when ghc-pkg doesn't find any matching packages in a given database -------------------------------------+------------------------------------- Reporter: dmwit | Owner: sibi Type: feature request | Status: closed Priority: normal | Milestone: Component: ghc-pkg | Version: 7.4.1 Resolution: fixed | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #10785 | Differential Rev(s): Wiki Page: | https://phabricator.haskell.org/D1575 -------------------------------------+------------------------------------- Changes (by bgamari): * status: patch => closed * resolution: => fixed -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/6119#comment:8> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #6119: complain when ghc-pkg doesn't find any matching packages in a given database
by GHC 07 Dec '15

07 Dec '15

#6119: complain when ghc-pkg doesn't find any matching packages in a given database -------------------------------------+------------------------------------- Reporter: dmwit | Owner: sibi Type: feature request | Status: patch Priority: normal | Milestone: Component: ghc-pkg | Version: 7.4.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #10785 | Differential Rev(s): Wiki Page: | https://phabricator.haskell.org/D1575 -------------------------------------+------------------------------------- Comment (by Ben Gamari <ben@…>): In [changeset:"3d55e41e72dc32281744c52afea380c1db577ee1/ghc" 3d55e41e/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="3d55e41e72dc32281744c52afea380c1db577ee1" ghc-pkg: Restore old behavior in colored version; fixes 6119 The behavior is changed to this: ``` ghc-pkg list blahblah /home/sibi/ghc/inplace/lib/package.conf.d (no packages) ``` instead of: ``` ghc-pkg list blahblah /home/sibi/ghc/inplace/lib/package.conf.d ``` Reviewers: austin, thomie, bgamari Reviewed By: thomie, bgamari Subscribers: thomie Differential Revision: https://phabricator.haskell.org/D1575 GHC Trac Issues: #6119 }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/6119#comment:7> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11171: the 'impossible' happened when messing with existenial quantification and typed holes
by GHC 07 Dec '15

07 Dec '15

#11171: the 'impossible' happened when messing with existenial quantification and typed holes -------------------------------------+------------------------------------- Reporter: TheKing42 | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.2 Keywords: | Operating System: Linux Architecture: x86_64 | Type of failure: Compile-time (amd64) | crash Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- First of all, I am quite honored that I was able to do something that GHC considered impossible. (Funny too. Just the other day, I was trying to break GHC and failed. Today, I was doing something I thought was rather mundane (although it was acting somewhat funky anyway)). Anyway, here is my error message: {{{ *Main> :r [1 of 1] Compiling Main ( pad.lhs, interpreted ) pad.lhs:12:25: Couldn't match type ‘f1’ with ‘f’ ‘f1’ is a rigid type variable bound by the type signature for wrap :: Functor f1 => f1 (CoInd f1) -> CoInd f1 at pad.lhs:11:11ghc: panic! (the 'impossible' happened) (GHC version 7.10.2 for x86_64-unknown-linux): No skolem info: f_abyA[sk] Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} And here is the code {{{#!hs > {-# LANGUAGE DeriveFunctor, Rank2Types, ExistentialQuantification #-} > newtype Ind f = Ind {flipinduct :: forall r. (f r -> r) -> r} > induction = flip flipinduct > data CoInd f = forall r. Coinduction (r -> f r) r > coinduction = Coinduction > data StringF rec = Nil | Cons Char rec deriving Functor > wrap :: (Functor f) => f (CoInd f) -> CoInd f > wrap fc = coinduction igo Nothing where > igo :: Maybe (CoInd f) -> _ > igo Nothing = fmap Just fc > igo (Just (Coinduction step seed)) = fmap (Just . Coinduction step) $ step seed > convert :: (Functor f) => Ind f -> CoInd f > convert = induction wrap > cowrap :: (Functor f) => Ind f -> f (Ind f) > cowrap = induction igo where > igo :: f (f (Ind f)) -> f (Ind f) > igo = fmap (\fInd -> Ind $ \fold -> fold $ fmap (`flipinduct` fold) fInd) > convert' :: (Functor f) => Ind f -> CoInd f > convert' = coinduction cowrap }}} I think the important parts are only "CoInd", "wrap", and "igo", but I included it all just to be sure (and I'm lazy). -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11171> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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Re: [GHC] #7169: Warning for incomplete record field label used as function
by GHC 07 Dec '15

07 Dec '15

#7169: Warning for incomplete record field label used as function -------------------------------------+------------------------------------- Reporter: goldfire | Owner: Type: feature request | Status: new Priority: normal | Milestone: 8.0.1 Component: Compiler | Version: 7.7 Resolution: | Keywords: Warnings, | newcomer Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by alanz): * cc: alanz (added) -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7169#comment:12> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11168: Cross build broken in commit 7af29da05d
by GHC 06 Dec '15

06 Dec '15

#11168: Cross build broken in commit 7af29da05d -------------------------------------+------------------------------------- Reporter: erikd | Owner: Type: bug | Status: new Priority: normal | Milestone: 8.0.1 Component: Build System | Version: 7.11 Keywords: cross-compile | 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 have been buildng a x86_64/linux to armhf/linux cross-compiler using: {{{ ./configure --target=arm-linux-gnueabihf -with-gcc=arm-linux-gnueabihf- gcc-5 make -j3 }}} for some time. However, after commit 7af29da05d, that results in: {{{ "inplace/bin/ghc-cabal" check libraries/base "inplace/bin/ghc-cabal" configure libraries/base dist-install "" --with-ghc="/md-new/home/erikd/Git/ghc-upstream/inplace/bin/ghc-stage1" --with-ghc-pkg="/md-new/home/erikd/Git/ghc-upstream/inplace/bin/ghc-pkg" --flags=integer-simple --disable-library-for-ghci --enable-library-vanilla --enable-library-for-ghci --disable-library-profiling --disable-shared --configure-option=CFLAGS="-Wall -marm -fno-stack-protector -Werror=unused-but-set-variable -Wno-error=inline" --configure-option=LDFLAGS=" " --configure-option=CPPFLAGS=" " --gcc-options="-Wall -marm -fno-stack-protector -Werror=unused-but-set-variable -Wno-error=inline " --configure-option=--host=arm-unknown-linux-gnueabihf --with-gcc="arm-linux-gnueabihf-gcc-5" --with-ld="/usr/bin/arm-linux-gnueabihf-ld.gold" --configure-option=--with-cc="arm-linux-gnueabihf-gcc-5" --with-ar="/usr/bin/arm-linux-gnueabihf-ar" --with-alex="/usr/bin/alex" --with-happy="/usr/bin/happy" Configuring base-4.9.0.0... configure: WARNING: unrecognized options: --with-compiler, --with-gcc checking for arm-unknown-linux-gnueabihf-gcc... no checking for gcc... gcc checking whether the C compiler works... no configure: error: in `/md-new/home/erikd/Git/ghc-upstream/libraries/base': configure: error: C compiler cannot create executables See `config.log' for more details libraries/base/ghc.mk:4: recipe for target 'libraries/base/dist-install/package-data.mk' failed make[1]: *** [libraries/base/dist-install/package-data.mk] Error 77 Makefile:121: recipe for target 'all' failed }}} It seems that the required GCC version doesn't get passed to configuration for Base. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11168> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #11128: New `-fwarn-noncanonical-monad-instances` warning
by GHC 06 Dec '15

06 Dec '15

#11128: New `-fwarn-noncanonical-monad-instances` warning -------------------------------------+------------------------------------- Reporter: hvr | Owner: hvr Type: feature | Status: new request | Priority: normal | Milestone: 8.0.1 Component: Compiler | Version: 7.10.2 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: -------------------------------------+------------------------------------- placeholder -- I needed a ticket number; will flesh out description asap -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11128> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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