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* Typos in comments [ci skip]Gabor Greif2017-01-251-1/+1
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* Show explicit quantifiers in conflicting definitions errorPhil de Joux2017-01-201-54/+92
| | | | | | | | | | | | | | | | This fixes #12441, where definitions in a Haskell module and its boot file which differed only in their quantifiers produced a confusing error message. Here we teach GHC to always show quantifiers for these errors. Reviewers: goldfire, simonmar, erikd, austin, hvr, bgamari Reviewed By: bgamari Subscribers: snowleopard, simonpj, mpickering, thomie Differential Revision: https://phabricator.haskell.org/D2734 GHC Trac Issues: #12441
* Update levity polymorphismRichard Eisenberg2017-01-191-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This commit implements the proposal in https://github.com/ghc-proposals/ghc-proposals/pull/29 and https://github.com/ghc-proposals/ghc-proposals/pull/35. Here are some of the pieces of that proposal: * Some of RuntimeRep's constructors have been shortened. * TupleRep and SumRep are now parameterized over a list of RuntimeReps. * This means that two types with the same kind surely have the same representation. Previously, all unboxed tuples had the same kind, and thus the fact above was false. * RepType.typePrimRep and friends now return a *list* of PrimReps. These functions can now work successfully on unboxed tuples. This change is necessary because we allow abstraction over unboxed tuple types and so cannot always handle unboxed tuples specially as we did before. * We sometimes have to create an Id from a PrimRep. I thus split PtrRep * into LiftedRep and UnliftedRep, so that the created Ids have the right strictness. * The RepType.RepType type was removed, as it didn't seem to help with * much. * The RepType.repType function is also removed, in favor of typePrimRep. * I have waffled a good deal on whether or not to keep VoidRep in TyCon.PrimRep. In the end, I decided to keep it there. PrimRep is *not* represented in RuntimeRep, and typePrimRep will never return a list including VoidRep. But it's handy to have in, e.g., ByteCodeGen and friends. I can imagine another design choice where we have a PrimRepV type that is PrimRep with an extra constructor. That seemed to be a heavier design, though, and I'm not sure what the benefit would be. * The last, unused vestiges of # (unliftedTypeKind) have been removed. * There were several pretty-printing bugs that this change exposed; * these are fixed. * We previously checked for levity polymorphism in the types of binders. * But we also must exclude levity polymorphism in function arguments. This is hard to check for, requiring a good deal of care in the desugarer. See Note [Levity polymorphism checking] in DsMonad. * In order to efficiently check for levity polymorphism in functions, it * was necessary to add a new bit of IdInfo. See Note [Levity info] in IdInfo. * It is now safe for unlifted types to be unsaturated in Core. Core Lint * is updated accordingly. * We can only know strictness after zonking, so several checks around * strictness in the type-checker (checkStrictBinds, the check for unlifted variables under a ~ pattern) have been moved to the desugarer. * Along the way, I improved the treatment of unlifted vs. banged * bindings. See Note [Strict binds checks] in DsBinds and #13075. * Now that we print type-checked source, we must be careful to print * ConLikes correctly. This is facilitated by a new HsConLikeOut constructor to HsExpr. Particularly troublesome are unlifted pattern synonyms that get an extra void# argument. * Includes a submodule update for haddock, getting rid of #. * New testcases: typecheck/should_fail/StrictBinds typecheck/should_fail/T12973 typecheck/should_run/StrictPats typecheck/should_run/T12809 typecheck/should_fail/T13105 patsyn/should_fail/UnliftedPSBind typecheck/should_fail/LevPolyBounded typecheck/should_compile/T12987 typecheck/should_compile/T11736 * Fixed tickets: #12809 #12973 #11736 #13075 #12987 * This also adds a test case for #13105. This test case is * "compile_fail" and succeeds, because I want the testsuite to monitor the error message. When #13105 is fixed, the test case will compile cleanly.
* Improve pretty-printing of typesSimon Peyton Jones2016-11-251-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In this commit commit 6c0f10fac767c49b65ed71e8eb8e78ca4f9062d5 Author: Ben Gamari <bgamari.foss@gmail.com> Date: Sun Nov 13 16:17:37 2016 -0500 Kill Type pretty-printer we switched to pretty-printing a type by converting it to an IfaceType and pretty printing that. Very good. This patch fixes two things * The new story is terrible for debug-printing with -ddump-tc-trace, because all the extra info in an open type was discarded ty the conversion to IfaceType. This patch adds IfaceTcTyVar to IfaceType, to carry a TcTyVar in debug situations. Quite an easy change, happily. These things never show up in interface files. * Now that we are going via IfaceType, it's essential to tidy before converting; otherwise forall k_23 k_34. blah is printed as forall k k. blah which is very unhelpful. Again this only shows up in debug printing.
* Kill Type pretty-printerBen Gamari2016-11-131-3/+6
| | | | | | | | | | | | | | | | | | | | | | Here we consolidate the pretty-printing logic for types in IfaceType. We need IfaceType regardless and the printer for Type can be implemented in terms of that for IfaceType. See #11660. Note that this is very much a work-in-progress. Namely I still have yet to ponder how to ease the hs-boot file situation, still need to rip out more dead code, need to move some of the special cases for, e.g., `*` to the IfaceType printer, and need to get it to validate. That being said, it comes close to validating as-is. Test Plan: Validate Reviewers: goldfire, austin Subscribers: goldfire, thomie, simonpj Differential Revision: https://phabricator.haskell.org/D2528 GHC Trac Issues: #11660
* New story for abstract data types in hsig files.Edward Z. Yang2016-10-201-3/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: In the old implementation of hsig files, we directly reused the implementation of abstract data types from hs-boot files. However, this was WRONG. Consider the following program (an abridged version of bkpfail24): {-# LANGUAGE GADTs #-} unit p where signature H1 where data T signature H2 where data T module M where import qualified H1 import qualified H2 f :: H1.T ~ H2.T => a -> b f x = x Prior to this patch, M was accepted, because the type inference engine concluded that H1.T ~ H2.T does not hold (indeed, *presently*, it does not). However, if we subsequently instantiate p with the same module for H1 and H2, H1.T ~ H2.T does hold! Unsound. The key is that abstract types from signatures need to be treated like *skolem variables*, since you can interpret a Backpack unit as a record which is universally quantified over all of its abstract types, as such (with some fake syntax for structural records): p :: forall t1 t2. { f :: t1 ~ t2 => a -> b } p = { f = \x -> x } -- ill-typed Clearly t1 ~ t2 is not solvable inside p, and also clearly it could be true at some point in the future, so we better not treat the lambda expression after f as inaccessible. The fix seems to be simple: do NOT eagerly fail when trying to simplify the given constraints. Instead, treat H1.T ~ H2.T as an irreducible constraint (rather than an insoluble one); this causes GHC to treat f as accessible--now we will typecheck the rest of the function (and correctly fail). Per the OutsideIn(X) paper, it's always sound to fail less when simplifying givens. We do NOT apply this fix to hs-boot files, where abstract data is also guaranteed to be nominally distinct (since it can't be implemented via a reexport or a type synonym.) This is a somewhat unnatural state of affairs (there's no way to really interpret this in Haskell land) but no reason to change behavior. I deleted "representationally distinct abstract data", which is never used anywhere in GHC. In the process of constructing this fix, I also realized our implementation of type synonym matching against abstract data was not sufficiently restrictive. In order for a type synonym T to be well-formed type, it must be a nullary synonym (i.e., type T :: * -> *, not type T a = ...). Furthermore, since we use abstract data when defining instances, they must not have any type family applications. More details in #12680. This probably deserves some sort of short paper report. Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu> Test Plan: validate Reviewers: goldfire, simonpj, austin, bgamari Subscribers: thomie Differential Revision: https://phabricator.haskell.org/D2594
* Clean up handling of known-key Names in interface filesBen Gamari2016-10-131-72/+109
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously BinIface had some dedicated logic for handling tuple names in the symbol table. As it turns out, this logic was essentially dead code as it was superceded by the special handling of known-key things. Here we cull the tuple code-path and use the known-key codepath for all tuple-ish things. This had a surprising number of knock-on effects, * constraint tuple datacons had to be made known-key (previously they were not) * IfaceTopBndr was changed from being a synonym of OccName to a synonym of Name (since we now need to be able to deserialize Names directly from interface files) * the change to IfaceTopBndr complicated fingerprinting, since we need to ensure that we don't go looking for the fingerprint of the thing we are currently fingerprinting in the fingerprint environment (see notes in MkIface). Handling this required distinguishing between binding and non-binding Name occurrences in the Binary serializers. * the original name cache logic which previously lived in IfaceEnv has been moved to a new NameCache module * I ripped tuples and sums out of knownKeyNames since they introduce a very large number of entries. During interface file deserialization we use static functions (defined in the new KnownUniques module) to map from a Unique to a known-key Name (the Unique better correspond to a known-key name!) When we need to do an original name cache lookup we rely on the parser implemented in isBuiltInOcc_maybe. * HscMain.allKnownKeyNames was folded into PrelInfo.knownKeyNames. * Lots of comments were sprinkled about describing the new scheme. Updates haddock submodule. Test Plan: Validate Reviewers: niteria, simonpj, austin, hvr Reviewed By: simonpj Subscribers: simonmar, niteria, thomie Differential Revision: https://phabricator.haskell.org/D2467 GHC Trac Issues: #12532, #12415
* The Backpack patch.Edward Z. Yang2016-10-081-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: This patch implements Backpack for GHC. It's a big patch but I've tried quite hard to keep things, by-in-large, self-contained. The user facing specification for Backpack can be found at: https://github.com/ezyang/ghc-proposals/blob/backpack/proposals/0000-backpack.rst A guide to the implementation can be found at: https://github.com/ezyang/ghc-proposals/blob/backpack-impl/proposals/0000-backpack-impl.rst Has a submodule update for Cabal, as well as a submodule update for filepath to handle more strict checking of cabal-version. Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu> Test Plan: validate Reviewers: simonpj, austin, simonmar, bgamari, goldfire Subscribers: thomie, mpickering Differential Revision: https://phabricator.haskell.org/D1482
* Axe RecFlag on TyCons.Edward Z. Yang2016-06-301-21/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: This commit removes the information about whether or not a TyCon is "recursive", as well as the code responsible for calculating this information. The original trigger for this change was complexity regarding how we computed the RecFlag for hs-boot files. The problem is that in order to determine if a TyCon is recursive or not, we need to determine if it was defined in an hs-boot file (if so, we conservatively assume that it is recursive.) It turns that doing this is quite tricky. The "obvious" strategy is to typecheck the hi-boot file (since we are eventually going to need the typechecked types to check if we properly implemented the hi-boot file) and just extract the names of all defined TyCons from the ModDetails, but this actually does not work well if Names from the hi-boot file are being knot-tied via if_rec_types: the "extraction" process will force thunks, which will force the typechecking process earlier than we have actually defined the types locally. Rather than work around all this trickiness (it certainly can be worked around, either by making interface loading MORE lazy, or just reading of the set of defined TyCons directly from the ModIface), we instead opted to excise the source of the problem, the RecFlag. For one, it is not clear if the RecFlag even makes sense, in the presence of higher-orderness: data T f a = MkT (f a) T doesn't look recursive, but if we instantiate f with T, then it very well is! It was all very shaky. So we just don't bother anymore. This has two user-visible implications: 1. is_too_recursive now assumes that all TyCons are recursive and will bail out in a way that is still mysterious to me if there are too many TyCons. 2. checkRecTc, which is used when stripping newtypes to get to representation, also assumes all TyCons are recursive, and will stop running if we hit the limit. The biggest risk for this patch is that we specialize less than we used to; however, the codeGen tests still seem to be passing. Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu> Reviewers: simonpj, austin, bgamari Subscribers: goldfire, thomie Differential Revision: https://phabricator.haskell.org/D2360
* Major patch to introduce TyConBinderSimon Peyton Jones2016-06-151-26/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Before this patch, following the TypeInType innovations, each TyCon had two lists: - tyConBinders :: [TyBinder] - tyConTyVars :: [TyVar] They were in 1-1 correspondence and contained overlapping information. More broadly, there were many places where we had to pass around this pair of lists, instead of a single list. This commit tidies all that up, by having just one list of binders in a TyCon: - tyConBinders :: [TyConBinder] The new data types look like this: Var.hs: data TyVarBndr tyvar vis = TvBndr tyvar vis data VisibilityFlag = Visible | Specified | Invisible type TyVarBinder = TyVarBndr TyVar VisibilityFlag TyCon.hs: type TyConBinder = TyVarBndr TyVar TyConBndrVis data TyConBndrVis = NamedTCB VisibilityFlag | AnonTCB TyCoRep.hs: data TyBinder = Named TyVarBinder | Anon Type Note that Var.TyVarBdr has moved from TyCoRep and has been made polymorphic in the tyvar and visiblity fields: type TyVarBinder = TyVarBndr TyVar VisibilityFlag -- Used in ForAllTy type TyConBinder = TyVarBndr TyVar TyConBndrVis -- Used in TyCon type IfaceForAllBndr = TyVarBndr IfaceTvBndr VisibilityFlag type IfaceTyConBinder = TyVarBndr IfaceTvBndr TyConBndrVis -- Ditto, in interface files There are a zillion knock-on changes, but everything arises from these types. It was a bit fiddly to get the module loops to work out right! Some smaller points ~~~~~~~~~~~~~~~~~~~ * Nice new functions TysPrim.mkTemplateKiTyVars TysPrim.mkTemplateTyConBinders which help you make the tyvar binders for dependently-typed TyCons. See comments with their definition. * The change showed up a bug in TcGenGenerics.tc_mkRepTy, where the code was making an assumption about the order of the kind variables in the kind of GHC.Generics.(:.:). I fixed this; see TcGenGenerics.mkComp.
* Re-add FunTy (big patch)Simon Peyton Jones2016-06-151-2/+2
| | | | | | | | | | | | | | | | | | | | | | With TypeInType Richard combined ForAllTy and FunTy, but that was often awkward, and yielded little benefit becuase in practice the two were always treated separately. This patch re-introduces FunTy. Specfically * New type data TyVarBinder = TvBndr TyVar VisibilityFlag This /always/ has a TyVar it. In many places that's just what what we want, so there are /lots/ of TyBinder -> TyVarBinder changes * TyBinder still exists: data TyBinder = Named TyVarBinder | Anon Type * data Type = ForAllTy TyVarBinder Type | FunTy Type Type | .... There are a LOT of knock-on changes, but they are all routine. The Haddock submodule needs to be updated too
* Add Outputable ShowHowMuchSimon Peyton Jones2016-05-101-0/+5
| | | | | I needed this instance when debugging, so I thought I'd add it permanently.
* Track specified/invisible more carefully.Richard Eisenberg2016-03-211-10/+10
| | | | | | | | | | | | | | In particular, this allows correct tracking of specified/invisible for variables in Haskell98 data constructors and in pattern synonyms. GADT-syntax constructors are harder, and are left until #11721. This was all inspired by Simon's comments to my fix for #11512, which this subsumes. Test case: ghci/scripts/TypeAppData [skip ci] (The test case fails because of an unrelated problem fixed in the next commit.)
* Fix printing of an `IfacePatSyn`Rik Steenkamp2016-03-051-10/+14
| | | | | | | | | | | | | | | | | Now the existentially quantified type variables are printed at the correct location when printing a pattern synonym type from an `IfacePatSyn`. The function `pprIfaceContextMaybe` has been removed as it is no longer needed. Fixes #11524. Reviewers: austin, goldfire, thomie, bgamari, mpickering Reviewed By: bgamari Differential Revision: https://phabricator.haskell.org/D1958 GHC Trac Issues: #11524
* Address #11471 by putting RuntimeRep in kinds.wip/runtime-repRichard Eisenberg2016-02-241-72/+76
| | | | | | | | | | | | | | | | | | | | | See Note [TYPE] in TysPrim. There are still some outstanding pieces in #11471 though, so this doesn't actually nail the bug. This commit also contains a few performance improvements: * Short-cut equality checking of nullary type syns * Compare types before kinds in eqType * INLINE coreViewOneStarKind * Store tycon binders separately from kinds. This resulted in a ~10% performance improvement in compiling the Cabal package. No change in functionality other than performance. (This affects the interface file format, though.) This commit updates the haddock submodule.
* Replace calls to `ptext . sLit` with `text`Jan Stolarek2016-01-181-57/+57
| | | | | | | | | | | | | | | | | | | | Summary: In the past the canonical way for constructing an SDoc string literal was the composition `ptext . sLit`. But for some time now we have function `text` that does the same. Plus it has some rules that optimize its runtime behaviour. This patch takes all uses of `ptext . sLit` in the compiler and replaces them with calls to `text`. The main benefits of this patch are clener (shorter) code and less dependencies between module, because many modules now do not need to import `FastString`. I don't expect any performance benefits - we mostly use SDocs to report errors and it seems there is little to be gained here. Test Plan: ./validate Reviewers: bgamari, austin, goldfire, hvr, alanz Subscribers: goldfire, thomie, mpickering Differential Revision: https://phabricator.haskell.org/D1784
* Visible type applicationRichard Eisenberg2015-12-241-1/+1
| | | | | | | | | | | | | This re-working of the typechecker algorithm is based on the paper "Visible type application", by Richard Eisenberg, Stephanie Weirich, and Hamidhasan Ahmed, to be published at ESOP'16. This patch introduces -XTypeApplications, which allows users to say, for example `id @Int`, which has type `Int -> Int`. See the changes to the user manual for details. This patch addresses tickets #10619, #5296, #10589.
* Refactoring onlySimon Peyton Jones2015-12-241-1/+1
| | | | | | | | | | | | | This moves code around to more sensible places. - Construction for CoAxiom is localised in FamInstEnv - orphNamesOfxx moves to CoreFVs - roughMatchTcs, instanceCantMatch moves to Unify - mkNewTypeCo moves from Coercion to FamInstEnv, and is renamed mkNewTypeCoAxiom, which makes more sense
* Random typo fixesHerbert Valerio Riedel2015-12-171-1/+1
| | | | [skip ci]
* Add kind equalities to GHC.Richard Eisenberg2015-12-111-79/+124
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This implements the ideas originally put forward in "System FC with Explicit Kind Equality" (ICFP'13). There are several noteworthy changes with this patch: * We now have casts in types. These change the kind of a type. See new constructor `CastTy`. * All types and all constructors can be promoted. This includes GADT constructors. GADT pattern matches take place in type family equations. In Core, types can now be applied to coercions via the `CoercionTy` constructor. * Coercions can now be heterogeneous, relating types of different kinds. A coercion proving `t1 :: k1 ~ t2 :: k2` proves both that `t1` and `t2` are the same and also that `k1` and `k2` are the same. * The `Coercion` type has been significantly enhanced. The documentation in `docs/core-spec/core-spec.pdf` reflects the new reality. * The type of `*` is now `*`. No more `BOX`. * Users can write explicit kind variables in their code, anywhere they can write type variables. For backward compatibility, automatic inference of kind-variable binding is still permitted. * The new extension `TypeInType` turns on the new user-facing features. * Type families and synonyms are now promoted to kinds. This causes trouble with parsing `*`, leading to the somewhat awkward new `HsAppsTy` constructor for `HsType`. This is dispatched with in the renamer, where the kind `*` can be told apart from a type-level multiplication operator. Without `-XTypeInType` the old behavior persists. With `-XTypeInType`, you need to import `Data.Kind` to get `*`, also known as `Type`. * The kind-checking algorithms in TcHsType have been significantly rewritten to allow for enhanced kinds. * The new features are still quite experimental and may be in flux. * TODO: Several open tickets: #11195, #11196, #11197, #11198, #11203. * TODO: Update user manual. Tickets addressed: #9017, #9173, #7961, #10524, #8566, #11142. Updates Haddock submodule.
* Refactor treatment of wildcardsSimon Peyton Jones2015-12-011-12/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch began as a modest refactoring of HsType and friends, to clarify and tidy up exactly where quantification takes place in types. Although initially driven by making the implementation of wildcards more tidy (and fixing a number of bugs), I gradually got drawn into a pretty big process, which I've been doing on and off for quite a long time. There is one compiler performance regression as a result of all this, in perf/compiler/T3064. I still need to look into that. * The principal driving change is described in Note [HsType binders] in HsType. Well worth reading! * Those data type changes drive almost everything else. In particular we now statically know where (a) implicit quantification only (LHsSigType), e.g. in instance declaratios and SPECIALISE signatures (b) implicit quantification and wildcards (LHsSigWcType) can appear, e.g. in function type signatures * As part of this change, HsForAllTy is (a) simplified (no wildcards) and (b) split into HsForAllTy and HsQualTy. The two contructors appear when and only when the correponding user-level construct appears. Again see Note [HsType binders]. HsExplicitFlag disappears altogether. * Other simplifications - ExprWithTySig no longer needs an ExprWithTySigOut variant - TypeSig no longer needs a PostRn name [name] field for wildcards - PatSynSig records a LHsSigType rather than the decomposed pieces - The mysterious 'GenericSig' is now 'ClassOpSig' * Renamed LHsTyVarBndrs to LHsQTyVars * There are some uninteresting knock-on changes in Haddock, because of the HsSyn changes I also did a bunch of loosely-related changes: * We already had type synonyms CoercionN/CoercionR for nominal and representational coercions. I've added similar treatment for TcCoercionN/TcCoercionR mkWpCastN/mkWpCastN All just type synonyms but jolly useful. * I record-ised ForeignImport and ForeignExport * I improved the (poor) fix to Trac #10896, by making TcTyClsDecls.checkValidTyCl recover from errors, but adding a harmless, abstract TyCon to the envt if so. * I did some significant refactoring in RnEnv.lookupSubBndrOcc, for reasons that I have (embarrassingly) now totally forgotten. It had to do with something to do with import and export Updates haddock submodule.
* Refactor default methods (Trac #11105)Simon Peyton Jones2015-11-251-12/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch does some signficant refactoring to the treatment of default methods in class declarations, and more generally to the type checking of type/class decls. Highlights: * When the class has a generic-default method, such as class C a where op :: a -> a -> Bool default op :: Ord a => a -> a -> a the ClassOpItem records the type of the generic-default, in this case the type (Ord a => a -> a -> a) * I killed off Class.DefMeth in favour of the very-similar BasicTypes.DefMethSpec. However it turned out to be better to use a Maybe, thus Maybe (DefMethSpec Type) with Nothing meaning "no default method". * In TcTyClsDecls.tcTyClGroup, we used to accumulate a [TyThing], but I found a way to make it much simpler, accumulating only a [TyCon]. Much less wrapping and unwrapping. * On the way I also fixed Trac #10896 in a better way. Instead of killing off all ambiguity checks whenever there are any type errors (the fix in commit 8e8b9ed), I instead recover in TcTyClsDecls.checkValidTyCl. There was a lot of associated simplification all round
* Fix inconsistent pretty-printing of type familiesMichał Sośnicki2015-11-181-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | After the changes, the three functions used to print type families were identical, so they are refactored into one. Original RHSs of data instance declarations are recreated and printed in user error messages. RHSs containing representation TyCons are printed in the Coercion Axioms section in a typechecker dump. Add vbar to the list of SDocs exported by Outputable. Replace all text "|" docs with it. Fixes #10839 Reviewers: goldfire, jstolarek, austin, bgamari Reviewed By: jstolarek Subscribers: jstolarek, thomie Differential Revision: https://phabricator.haskell.org/D1441 GHC Trac Issues: #10839
* Generate Typeable info at definition sitesBen Gamari2015-10-301-52/+49
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is the second attempt at merging D757. This patch implements the idea floated in Trac #9858, namely that we should generate type-representation information at the data type declaration site, rather than when solving a Typeable constraint. However, this turned out quite a bit harder than I expected. I still think it's the right thing to do, and it's done now, but it was quite a struggle. See particularly * Note [Grand plan for Typeable] in TcTypeable (which is a new module) * Note [The overall promotion story] in DataCon (clarifies existing stuff) The most painful bit was that to generate Typeable instances (ie TyConRepName bindings) for every TyCon is tricky for types in ghc-prim etc: * We need to have enough data types around to *define* a TyCon * Many of these types are wired-in Also, to minimise the code generated for each data type, I wanted to generate pure data, not CAFs with unpackCString# stuff floating about. Performance ~~~~~~~~~~~ Three perf/compiler tests start to allocate quite a bit more. This isn't surprising, because they all allocate zillions of data types, with practically no other code, esp. T1969 * T1969: GHC allocates 19% more * T4801: GHC allocates 13% more * T5321FD: GHC allocates 13% more * T9675: GHC allocates 11% more * T783: GHC allocates 11% more * T5642: GHC allocates 10% more I'm treating this as acceptable. The payoff comes in Typeable-heavy code. Remaining to do ~~~~~~~~~~~~~~~ * I think that "TyCon" and "Module" are over-generic names to use for the runtime type representations used in GHC.Typeable. Better might be "TrTyCon" and "TrModule". But I have not yet done this * Add more info the the "TyCon" e.g. source location where it was defined * Use the new "Module" type to help with Trac Trac #10068 * It would be possible to generate TyConRepName (ie Typeable instances) selectively rather than all the time. We'd need to persist the information in interface files. Lacking a motivating reason I have not done this, but it would not be difficult. Refactoring ~~~~~~~~~~~ As is so often the case, I ended up refactoring more than I intended. In particular * In TyCon, a type *family* (whether type or data) is repesented by a FamilyTyCon * a algebraic data type (including data/newtype instances) is represented by AlgTyCon This wasn't true before; a data family was represented as an AlgTyCon. There are some corresponding changes in IfaceSyn. * Also get rid of the (unhelpfully named) tyConParent. * In TyCon define 'Promoted', isomorphic to Maybe, used when things are optionally promoted; and use it elsewhere in GHC. * Cleanup handling of knownKeyNames * Each TyCon, including promoted TyCons, contains its TyConRepName, if it has one. This is, in effect, the name of its Typeable instance. Updates haddock submodule Test Plan: Let Harbormaster validate Reviewers: austin, hvr, goldfire Subscribers: goldfire, thomie Differential Revision: https://phabricator.haskell.org/D1404 GHC Trac Issues: #9858
* Revert "Generate Typeable info at definition sites"Ben Gamari2015-10-291-49/+52
| | | | | | | | This reverts commit bef2f03e4d56d88a7e9752a7afd6a0a35616da6c. This merge was botched Also reverts haddock submodule.
* Generate Typeable info at definition sitesBen Gamari2015-10-291-52/+49
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch implements the idea floated in Trac #9858, namely that we should generate type-representation information at the data type declaration site, rather than when solving a Typeable constraint. However, this turned out quite a bit harder than I expected. I still think it's the right thing to do, and it's done now, but it was quite a struggle. See particularly * Note [Grand plan for Typeable] in TcTypeable (which is a new module) * Note [The overall promotion story] in DataCon (clarifies existing stuff) The most painful bit was that to generate Typeable instances (ie TyConRepName bindings) for every TyCon is tricky for types in ghc-prim etc: * We need to have enough data types around to *define* a TyCon * Many of these types are wired-in Also, to minimise the code generated for each data type, I wanted to generate pure data, not CAFs with unpackCString# stuff floating about. Performance ~~~~~~~~~~~ Three perf/compiler tests start to allocate quite a bit more. This isn't surprising, because they all allocate zillions of data types, with practically no other code, esp. T1969 * T3294: GHC allocates 110% more (filed #11030 to track this) * T1969: GHC allocates 30% more * T4801: GHC allocates 14% more * T5321FD: GHC allocates 13% more * T783: GHC allocates 12% more * T9675: GHC allocates 12% more * T5642: GHC allocates 10% more * T9961: GHC allocates 6% more * T9203: Program allocates 54% less I'm treating this as acceptable. The payoff comes in Typeable-heavy code. Remaining to do ~~~~~~~~~~~~~~~ * I think that "TyCon" and "Module" are over-generic names to use for the runtime type representations used in GHC.Typeable. Better might be "TrTyCon" and "TrModule". But I have not yet done this * Add more info the the "TyCon" e.g. source location where it was defined * Use the new "Module" type to help with Trac Trac #10068 * It would be possible to generate TyConRepName (ie Typeable instances) selectively rather than all the time. We'd need to persist the information in interface files. Lacking a motivating reason I have not done this, but it would not be difficult. Refactoring ~~~~~~~~~~~ As is so often the case, I ended up refactoring more than I intended. In particular * In TyCon, a type *family* (whether type or data) is repesented by a FamilyTyCon * a algebraic data type (including data/newtype instances) is represented by AlgTyCon This wasn't true before; a data family was represented as an AlgTyCon. There are some corresponding changes in IfaceSyn. * Also get rid of the (unhelpfully named) tyConParent. * In TyCon define 'Promoted', isomorphic to Maybe, used when things are optionally promoted; and use it elsewhere in GHC. * Cleanup handling of knownKeyNames * Each TyCon, including promoted TyCons, contains its TyConRepName, if it has one. This is, in effect, the name of its Typeable instance. Requires update of the haddock submodule. Differential Revision: https://phabricator.haskell.org/D757
* Record pattern synonymsMatthew Pickering2015-10-291-6/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch implements an extension to pattern synonyms which allows user to specify pattern synonyms using record syntax. Doing so generates appropriate selectors and update functions. === Interaction with Duplicate Record Fields === The implementation given here isn't quite as general as it could be with respect to the recently-introduced `DuplicateRecordFields` extension. Consider the following module: {-# LANGUAGE DuplicateRecordFields #-} {-# LANGUAGE PatternSynonyms #-} module Main where pattern S{a, b} = (a, b) pattern T{a} = Just a main = do print S{ a = "fst", b = "snd" } print T{ a = "a" } In principle, this ought to work, because there is no ambiguity. But at the moment it leads to a "multiple declarations of a" error. The problem is that pattern synonym record selectors don't do the same name mangling as normal datatypes when DuplicateRecordFields is enabled. They could, but this would require some work to track the field label and selector name separately. In particular, we currently represent datatype selectors in the third component of AvailTC, but pattern synonym selectors are just represented as Avails (because they don't have a corresponding type constructor). Moreover, the GlobalRdrElt for a selector currently requires it to have a parent tycon. (example due to Adam Gundry) === Updating Explicitly Bidirectional Pattern Synonyms === Consider the following ``` pattern Silly{a} <- [a] where Silly a = [a, a] f1 = a [5] -- 5 f2 = [5] {a = 6} -- currently [6,6] ``` === Fixing Polymorphic Updates === They were fixed by adding these two lines in `dsExpr`. This might break record updates but will be easy to fix. ``` + ; let req_wrap = mkWpTyApps (mkTyVarTys univ_tvs) - , pat_wrap = idHsWrapper } +, pat_wrap = req_wrap } ``` === Mixed selectors error === Note [Mixed Record Field Updates] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Consider the following pattern synonym. data MyRec = MyRec { foo :: Int, qux :: String } pattern HisRec{f1, f2} = MyRec{foo = f1, qux=f2} This allows updates such as the following updater :: MyRec -> MyRec updater a = a {f1 = 1 } It would also make sense to allow the following update (which we reject). updater a = a {f1 = 1, qux = "two" } ==? MyRec 1 "two" This leads to confusing behaviour when the selectors in fact refer the same field. updater a = a {f1 = 1, foo = 2} ==? ??? For this reason, we reject a mixture of pattern synonym and normal record selectors in the same update block. Although of course we still allow the following. updater a = (a {f1 = 1}) {foo = 2} > updater (MyRec 0 "str") MyRec 2 "str"
* Pattern synonyms: swap provided/requiredSimon Peyton Jones2015-10-281-1/+1
| | | | | | | | | | | | | | This patch swaps the order of provided and required constraints in a pattern signature, so it now goes pattern P :: req => prov => t1 -> ... tn -> res_ty See the long discussion in Trac #10928. I think I have found all the places, but I could have missed something particularly in comments. There is a Haddock changes; so a submodule update.
* Implement DuplicateRecordFieldsAdam Gundry2015-10-161-25/+49
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This implements DuplicateRecordFields, the first part of the OverloadedRecordFields extension, as described at https://ghc.haskell.org/trac/ghc/wiki/Records/OverloadedRecordFields/DuplicateRecordFields This includes fairly wide-ranging changes in order to allow multiple records within the same module to use the same field names. Note that it does *not* allow record selector functions to be used if they are ambiguous, and it does not have any form of type-based disambiguation for selectors (but it does for updates). Subsequent parts will make overloading selectors possible using orthogonal extensions, as described on the wiki pages. This part touches quite a lot of the codebase, and requires changes to several GHC API datatypes in order to distinguish between field labels (which may be overloaded) and selector function names (which are always unique). The Haddock submodule has been adapted to compile with the GHC API changes, but it will need further work to properly support modules that use the DuplicateRecordFields extension. Test Plan: New tests added in testsuite/tests/overloadedrecflds; these will be extended once the other parts are implemented. Reviewers: goldfire, bgamari, simonpj, austin Subscribers: sjcjoosten, haggholm, mpickering, bgamari, tibbe, thomie, goldfire Differential Revision: https://phabricator.haskell.org/D761
* Show minimal complete definitions in ghci (#10847)Moritz Kiefer2015-09-171-3/+27
| | | | | | | | | | | Show the minimal complete definition on :info in ghci. They are shown like MINIMAL pragmas in code. If the minimal complete definition is empty or only a specific method from a class is requested, nothing is shown. Reviewed By: simonpj, austin, thomie Differential Revision: https://phabricator.haskell.org/D1241
* Injective type familiesJan Stolarek2015-09-031-8/+27
| | | | | | | | | | | | | | | | | | | For details see #6018, Phab:D202 and the wiki page: https://ghc.haskell.org/trac/ghc/wiki/InjectiveTypeFamilies This patch also wires-in Maybe data type and updates haddock submodule. Test Plan: ./validate Reviewers: simonpj, goldfire, austin, bgamari Subscribers: mpickering, bgamari, alanz, thomie, goldfire, simonmar, carter Differential Revision: https://phabricator.haskell.org/D202 GHC Trac Issues: #6018
* Replace HsBang type with HsSrcBang and HsImplBangAdam Sandberg Eriksson2015-08-101-13/+36
| | | | | | | | | | | | Updates haddock submodule. Reviewers: tibbe, goldfire, simonpj, austin, bgamari Reviewed By: simonpj, bgamari Subscribers: goldfire, thomie, mpickering Differential Revision: https://phabricator.haskell.org/D1069
* Improve warnings for rules that might not fireSimon Peyton Jones2015-07-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | Two main things here * Previously we only warned about the "head" function of the rule, but actually the warning applies to any free variable on the LHS. * We now warn not only when one of these free vars can inline, but also if it has an active RULE (c.f. Trac #10528) See Note [Rules and inlining/other rules] in Desugar This actually shows up quite a few warnings in the libraries, notably in Control.Arrow, where it correctly points out that rules like "compose/arr" forall f g . (arr f) . (arr g) = arr (f . g) might never fire, because the rule for 'arr' (dictionary selection) might fire first. I'm not really sure what to do here; there is some discussion in Trac #10595. A minor change is adding BasicTypes.pprRuleName to pretty-print RuleName.
* Refactor tuple constraintsSimon Peyton Jones2015-05-181-5/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make tuple constraints be handled by a perfectly ordinary type class, with the component constraints being the superclasses: class (c1, c2) => (c2, c2) This change was provoked by #10359 inability to re-use a given tuple constraint as a whole #9858 confusion between term tuples and constraint tuples but it's generally a very nice simplification. We get rid of - In Type, the TuplePred constructor of PredTree, and all the code that dealt with TuplePreds - In TcEvidence, the constructors EvTupleMk, EvTupleSel See Note [How tuples work] in TysWiredIn. Of course, nothing is ever entirely simple. This one proved quite fiddly. - I did quite a bit of renaming, which makes this patch touch a lot of modules. In partiuclar tupleCon -> tupleDataCon. - I made constraint tuples known-key rather than wired-in. This is different to boxed/unboxed tuples, but it proved awkward to have all the superclass selectors wired-in. Easier just to use the standard mechanims. - While I was fiddling with known-key names, I split the TH Name definitions out of DsMeta into a new module THNames. That meant that the known-key names can all be gathered in PrelInfo, without causing module loops. - I found that the parser was parsing an import item like T( .. ) as a *data constructor* T, and then using setRdrNameSpace to fix it. Stupid! So I changed the parser to parse a *type constructor* T, which means less use of setRdrNameSpace. I also improved setRdrNameSpace to behave better on Exact Names. Largely on priciple; I don't think it matters a lot. - When compiling a data type declaration for a wired-in thing like tuples (,), or lists, we don't really need to look at the declaration. We have the wired-in thing! And not doing so avoids having to line up the uniques for data constructor workers etc. See Note [Declarations for wired-in things] - I found that FunDeps.oclose wasn't taking superclasses into account; easily fixed. - Some error message refactoring for invalid constraints in TcValidity - Haddock needs to absorb the change too; so there is a submodule update
* Revert multiple commitsAustin Seipp2015-05-141-4/+5
| | | | | | | | | | | | | | | | | | | | This reverts multiple commits from Simon: - 04a484eafc9eb9f8774b4bdd41a5dc6c9f640daf Test Trac #10359 - a9ccd37add8315e061c02e5bf26c08f05fad9ac9 Test Trac #10403 - c0aae6f699cbd222d826d0b8d78d6cb3f682079e Test Trac #10248 - eb6ca851f553262efe0824b8dcbe64952de4963d Make the "matchable-given" check happen first - ca173aa30467a0b1023682d573fcd94244d85c50 Add a case to checkValidTyCon - 51cbad15f86fca1d1b0e777199eb1079a1b64d74 Update haddock submodule - 6e1174da5b8e0b296f5bfc8b39904300d04eb5b7 Separate transCloVarSet from fixVarSet - a8493e03b89f3b3bfcdb6005795de050501f5c29 Fix imports in HscMain (stage2) - a154944bf07b2e13175519bafebd5a03926bf105 Two wibbles to fix the build - 5910a1bc8142b4e56a19abea104263d7bb5c5d3f Change in capitalisation of error msg - 130e93aab220bdf14d08028771f83df210da340b Refactor tuple constraints - 8da785d59f5989b9a9df06386d5bd13f65435bc0 Delete commented-out line These break the build by causing Haddock to fail mysteriously when trying to examine GHC.Prim it seems.
* Refactor tuple constraintsSimon Peyton Jones2015-05-131-5/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make tuple constraints be handled by a perfectly ordinary type class, with the component constraints being the superclasses: class (c1, c2) => (c2, c2) This change was provoked by #10359 inability to re-use a given tuple constraint as a whole #9858 confusion between term tuples and constraint tuples but it's generally a very nice simplification. We get rid of - In Type, the TuplePred constructor of PredTree, and all the code that dealt with TuplePreds - In TcEvidence, the constructors EvTupleMk, EvTupleSel See Note [How tuples work] in TysWiredIn. Of course, nothing is ever entirely simple. This one proved quite fiddly. - I did quite a bit of renaming, which makes this patch touch a lot of modules. In partiuclar tupleCon -> tupleDataCon. - I made constraint tuples known-key rather than wired-in. This is different to boxed/unboxed tuples, but it proved awkward to have all the superclass selectors wired-in. Easier just to use the standard mechanims. - While I was fiddling with known-key names, I split the TH Name definitions out of DsMeta into a new module THNames. That meant that the known-key names can all be gathered in PrelInfo, without causing module loops. - I found that the parser was parsing an import item like T( .. ) as a *data constructor* T, and then using setRdrNameSpace to fix it. Stupid! So I changed the parser to parse a *type constructor* T, which means less use of setRdrNameSpace. I also improved setRdrNameSpace to behave better on Exact Names. Largely on priciple; I don't think it matters a lot. - When compiling a data type declaration for a wired-in thing like tuples (,), or lists, we don't really need to look at the declaration. We have the wired-in thing! And not doing so avoids having to line up the uniques for data constructor workers etc. See Note [Declarations for wired-in things] - I found that FunDeps.oclose wasn't taking superclasses into account; easily fixed. - Some error message refactoring for invalid constraints in TcValidity
* Permit empty closed type familiesAdam Gundry2015-05-041-15/+18
| | | | | | | | | | | | | | | | | | | Fixes #9840 and #10306, and includes an alternative resolution to #8028. This permits empty closed type families, and documents them in the user guide. It updates the Haddock submodule to support the API change. Test Plan: Added `indexed-types/should_compile/T9840` and updated `indexed-types/should_fail/ClosedFam4` and `th/T8028`. Reviewers: austin, simonpj, goldfire Reviewed By: goldfire Subscribers: bgamari, jstolarek, thomie, goldfire Differential Revision: https://phabricator.haskell.org/D841 GHC Trac Issues: #9840, #10306
* More comments on HsBangSimon Peyton Jones2015-01-111-1/+2
| | | | In particular about the dcSrcBangs field of an imported DataCon
* Major patch to add -fwarn-redundant-constraintsSimon Peyton Jones2015-01-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The idea was promted by Trac #9939, but it was Christmas, so I did some recreational programming that went much further. The idea is to warn when a constraint in a user-supplied context is redundant. Everything is described in detail in Note [Tracking redundant constraints] in TcSimplify. Main changes: * The new ic_status field in an implication, of type ImplicStatus. It replaces ic_insol, and includes information about redundant constraints. * New function TcSimplify.setImplicationStatus sets the ic_status. * TcSigInfo has sig_report_redundant field to say whenther a redundant constraint should be reported; and similarly the FunSigCtxt constructor of UserTypeCtxt * EvBinds has a field eb_is_given, to record whether it is a given or wanted binding. Some consequential chagnes to creating an evidence binding (so that we record whether it is given or wanted). * AbsBinds field abs_ev_binds is now a *list* of TcEvBiinds; see Note [Typechecking plan for instance declarations] in TcInstDcls * Some significant changes to the type checking of instance declarations; Note [Typechecking plan for instance declarations] in TcInstDcls. * I found that TcErrors.relevantBindings was failing to zonk the origin of the constraint it was looking at, and hence failing to find some relevant bindings. Easy to fix, and orthogonal to everything else, but hard to disentangle. Some minor refactorig: * TcMType.newSimpleWanteds moves to Inst, renamed as newWanteds * TcClassDcl and TcInstDcls now have their own code for typechecking a method body, rather than sharing a single function. The shared function (ws TcClassDcl.tcInstanceMethodBody) didn't have much code and the differences were growing confusing. * Add new function TcRnMonad.pushLevelAndCaptureConstraints, and use it * Add new function Bag.catBagMaybes, and use it in TcSimplify
* Eliminate so-called "silent superclass parameters"Simon Peyton Jones2014-12-231-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The purpose of silent superclass parameters was to solve the awkward problem of superclass dictinaries being bound to bottom. See THE PROBLEM in Note [Recursive superclasses] in TcInstDcls Although the silent-superclass idea worked, * It had non-local consequences, and had effects even in Haddock, where we had to discard silent parameters before displaying instance declarations * It had unexpected peformance costs, shown up by Trac #3064 and its test case. In monad-transformer code, when constructing a Monad dictionary you had to pass an Applicative dictionary; and to construct that you neede a Functor dictionary. Yet these extra dictionaries were often never used. (All this got much worse when we added Applicative as a superclass of Monad.) Test T3064 compiled *far* faster after silent superclasses were eliminated. * It introduced new bugs. For example SilentParametersOverlapping, T5051, and T7862, all failed to compile because of instance overlap directly because of the silent-superclass trick. So this patch takes a new approach, which I worked out with Dimitrios in the closing hours before Christmas. It is described in detail in THE PROBLEM in Note [Recursive superclasses] in TcInstDcls. Seems to work great! Quite a bit of knock-on effect * The main implementation work is in tcSuperClasses in TcInstDcls Everything else is fall-out * IdInfo.DFunId no longer needs its n-silent argument * Ditto IDFunId in IfaceSyn * Hence interface file format changes * Now that DFunIds do not have silent superclass parameters, printing out instance declarations is simpler. There is tiny knock-on effect in Haddock, so that submodule is updated * I realised that when computing the "size of a dictionary type" in TcValidity.sizePred, we should be rather conservative about type functions, which can arbitrarily increase the size of a type. Hence the new datatype TypeSize, which has a TSBig constructor for "arbitrarily big". * instDFunType moves from TcSMonad to Inst * Interestingly, CmmNode and CmmExpr both now need a non-silent (Ord r) in a couple of instance declarations. These were previously silent but must now be explicit. * Quite a bit of wibbling in error messages
* Add a provenance field to universal coercions.Iavor S. Diatchki2014-12-171-1/+1
| | | | | | | | | | | Universal coercions allow casting between arbitrary types, so it is a good idea to keep track where they came from, which now we can do by using the provenance field in `UnivCo`. This is also handy for type-checker plugins that provide functionality beyond what's expressible by GHC's standard coercions: such plugins can generate universal coercions, but they should still tag them, so that if something goes wrong we can link the casts to the plugin.
* Source notes (Core support)Peter Wortmann2014-12-161-0/+21
| | | | | | | | | | | | | | | | | | | | | | This patch introduces "SourceNote" tickishs that link Core to the source code that generated it. The idea is to retain these source code links throughout code transformations so we can eventually relate object code all the way back to the original source (which we can, say, encode as DWARF information to allow debugging). We generate these SourceNotes like other tickshs in the desugaring phase. The activating command line flag is "-g", consistent with the flag other compilers use to decide DWARF generation. Keeping ticks from getting into the way of Core transformations is tricky, but doable. The changes in this patch produce identical Core in all cases I tested -- which at this point is GHC, all libraries and nofib. Also note that this pass creates *lots* of tick nodes, which we reduce somewhat by removing duplicated and overlapping source ticks. This will still cause significant Tick "clumps" - a possible future optimization could be to make Tick carry a list of Tickishs instead of one at a time. (From Phabricator D169)
* compiler: de-lhs iface/Austin Seipp2014-12-031-0/+1836
Signed-off-by: Austin Seipp <austin@well-typed.com>
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