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* Type vs Constraint: finally nailedSimon Peyton Jones2022-11-111-17/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This big patch addresses the rats-nest of issues that have plagued us for years, about the relationship between Type and Constraint. See #11715/#21623. The main payload of the patch is: * To introduce CONSTRAINT :: RuntimeRep -> Type * To make TYPE and CONSTRAINT distinct throughout the compiler Two overview Notes in GHC.Builtin.Types.Prim * Note [TYPE and CONSTRAINT] * Note [Type and Constraint are not apart] This is the main complication. The specifics * New primitive types (GHC.Builtin.Types.Prim) - CONSTRAINT - ctArrowTyCon (=>) - tcArrowTyCon (-=>) - ccArrowTyCon (==>) - funTyCon FUN -- Not new See Note [Function type constructors and FunTy] and Note [TYPE and CONSTRAINT] * GHC.Builtin.Types: - New type Constraint = CONSTRAINT LiftedRep - I also stopped nonEmptyTyCon being built-in; it only needs to be wired-in * Exploit the fact that Type and Constraint are distinct throughout GHC - Get rid of tcView in favour of coreView. - Many tcXX functions become XX functions. e.g. tcGetCastedTyVar --> getCastedTyVar * Kill off Note [ForAllTy and typechecker equality], in (old) GHC.Tc.Solver.Canonical. It said that typechecker-equality should ignore the specified/inferred distinction when comparein two ForAllTys. But that wsa only weakly supported and (worse) implies that we need a separate typechecker equality, different from core equality. No no no. * GHC.Core.TyCon: kill off FunTyCon in data TyCon. There was no need for it, and anyway now we have four of them! * GHC.Core.TyCo.Rep: add two FunTyFlags to FunCo See Note [FunCo] in that module. * GHC.Core.Type. Lots and lots of changes driven by adding CONSTRAINT. The key new function is sORTKind_maybe; most other changes are built on top of that. See also `funTyConAppTy_maybe` and `tyConAppFun_maybe`. * Fix a longstanding bug in GHC.Core.Type.typeKind, and Core Lint, in kinding ForAllTys. See new tules (FORALL1) and (FORALL2) in GHC.Core.Type. (The bug was that before (forall (cv::t1 ~# t2). blah), where blah::TYPE IntRep, would get kind (TYPE IntRep), but it should be (TYPE LiftedRep). See Note [Kinding rules for types] in GHC.Core.Type. * GHC.Core.TyCo.Compare is a new module in which we do eqType and cmpType. Of course, no tcEqType any more. * GHC.Core.TyCo.FVs. I moved some free-var-like function into this module: tyConsOfType, visVarsOfType, and occCheckExpand. Refactoring only. * GHC.Builtin.Types. Compiletely re-engineer boxingDataCon_maybe to have one for each /RuntimeRep/, rather than one for each /Type/. This dramatically widens the range of types we can auto-box. See Note [Boxing constructors] in GHC.Builtin.Types The boxing types themselves are declared in library ghc-prim:GHC.Types. GHC.Core.Make. Re-engineer the treatment of "big" tuples (mkBigCoreVarTup etc) GHC.Core.Make, so that it auto-boxes unboxed values and (crucially) types of kind Constraint. That allows the desugaring for arrows to work; it gathers up free variables (including dictionaries) into tuples. See Note [Big tuples] in GHC.Core.Make. There is still work to do here: #22336. But things are better than before. * GHC.Core.Make. We need two absent-error Ids, aBSENT_ERROR_ID for types of kind Type, and aBSENT_CONSTRAINT_ERROR_ID for vaues of kind Constraint. Ditto noInlineId vs noInlieConstraintId in GHC.Types.Id.Make; see Note [inlineId magic]. * GHC.Core.TyCo.Rep. Completely refactor the NthCo coercion. It is now called SelCo, and its fields are much more descriptive than the single Int we used to have. A great improvement. See Note [SelCo] in GHC.Core.TyCo.Rep. * GHC.Core.RoughMap.roughMatchTyConName. Collapse TYPE and CONSTRAINT to a single TyCon, so that the rough-map does not distinguish them. * GHC.Core.DataCon - Mainly just improve documentation * Some significant renamings: GHC.Core.Multiplicity: Many --> ManyTy (easier to grep for) One --> OneTy GHC.Core.TyCo.Rep TyCoBinder --> GHC.Core.Var.PiTyBinder GHC.Core.Var TyCoVarBinder --> ForAllTyBinder AnonArgFlag --> FunTyFlag ArgFlag --> ForAllTyFlag GHC.Core.TyCon TyConTyCoBinder --> TyConPiTyBinder Many functions are renamed in consequence e.g. isinvisibleArgFlag becomes isInvisibleForAllTyFlag, etc * I refactored FunTyFlag (was AnonArgFlag) into a simple, flat data type data FunTyFlag = FTF_T_T -- (->) Type -> Type | FTF_T_C -- (-=>) Type -> Constraint | FTF_C_T -- (=>) Constraint -> Type | FTF_C_C -- (==>) Constraint -> Constraint * GHC.Tc.Errors.Ppr. Some significant refactoring in the TypeEqMisMatch case of pprMismatchMsg. * I made the tyConUnique field of TyCon strict, because I saw code with lots of silly eval's. That revealed that GHC.Settings.Constants.mAX_SUM_SIZE can only be 63, because we pack the sum tag into a 6-bit field. (Lurking bug squashed.) Fixes * #21530 Updates haddock submodule slightly. Performance changes ~~~~~~~~~~~~~~~~~~~ I was worried that compile times would get worse, but after some careful profiling we are down to a geometric mean 0.1% increase in allocation (in perf/compiler). That seems fine. There is a big runtime improvement in T10359 Metric Decrease: LargeRecord MultiLayerModulesTH_OneShot T13386 T13719 Metric Increase: T8095
* Remove TCvSubst and use Subst for both term and type-level substYiyun Liu2022-08-041-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch removes the TCvSubst data type and instead uses Subst as the environment for both term and type level substitution. This change is partially motivated by the existential type proposal, which will introduce types that contain expressions and therefore forces us to carry around an "IdSubstEnv" even when substituting for types. It also reduces the amount of code because "Subst" and "TCvSubst" share a lot of common operations. There isn't any noticeable impact on performance (geo. mean for ghc/alloc is around 0.0% but we have -94 loc and one less data type to worry abount). Currently, the "TCvSubst" data type for substitution on types is identical to the "Subst" data type except the former doesn't store "IdSubstEnv". Using "Subst" for type-level substitution means there will be a redundant field stored in the data type. However, in cases where the substitution starts from the expression, using "Subst" for type-level substitution saves us from having to project "Subst" into a "TCvSubst". This probably explains why the allocation is mostly even despite the redundant field. The patch deletes "TCvSubst" and moves "Subst" and its relevant functions from "GHC.Core.Subst" into "GHC.Core.TyCo.Subst". Substitution on expressions is still defined in "GHC.Core.Subst" so we don't have to expose the definition of "Expr" in the hs-boot file that "GHC.Core.TyCo.Subst" must import to refer to "IdSubstEnv" (whose codomain is "CoreExpr"). Most functions named fooTCvSubst are renamed into fooSubst with a few exceptions (e.g. "isEmptyTCvSubst" is a distinct function from "isEmptySubst"; the former ignores the emptiness of "IdSubstEnv"). These exceptions mainly exist for performance reasons and will go away when "Expr" and "Type" are mutually recursively defined (we won't be able to take those shortcuts if we can't make the assumption that expressions don't appear in types).
* Minor cleanupKrzysztof Gogolewski2022-04-011-2/+2
| | | | | | | | | | | - Remove unused functions exprToCoercion_maybe, applyTypeToArg, typeMonoPrimRep_maybe, runtimeRepMonoPrimRep_maybe. - Replace orValid with a simpler check - Use splitAtList in applyTysX - Remove calls to extra_clean in the testsuite; it does not do anything. Metric Decrease: T18223
* Fix and simplify DeriveAnyClass's context inference using SubTypePredSpecRyan Scott2022-03-241-96/+244
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As explained in `Note [Gathering and simplifying constraints for DeriveAnyClass]` in `GHC.Tc.Deriv.Infer`, `DeriveAnyClass` infers instance contexts by emitting implication constraints. Previously, these implication constraints were constructed by hand. This is a terribly trick thing to get right, as it involves a delicate interplay of skolemisation, metavariable instantiation, and `TcLevel` bumping. Despite much effort, we discovered in #20719 that the implementation was subtly incorrect, leading to valid programs being rejected. While we could scrutinize the code that manually constructs implication constraints and repair it, there is a better, less error-prone way to do things. After all, the heart of `DeriveAnyClass` is generating code which fills in each class method with defaults, e.g., `foo = $gdm_foo`. Typechecking this sort of code is tantamount to calling `tcSubTypeSigma`, as we much ensure that the type of `$gdm_foo` is a subtype of (i.e., more polymorphic than) the type of `foo`. As an added bonus, `tcSubTypeSigma` is a battle-tested function that handles skolemisation, metvariable instantiation, `TcLevel` bumping, and all other means of tricky bookkeeping correctly. With this insight, the solution to the problems uncovered in #20719 is simple: use `tcSubTypeSigma` to check if `$gdm_foo`'s type is a subtype of `foo`'s type. As a side effect, `tcSubTypeSigma` will emit exactly the implication constraint that we were attempting to construct by hand previously. Moreover, it does so correctly, fixing #20719 as a consequence. This patch implements the solution thusly: * The `PredSpec` data type (previously named `PredOrigin`) is now split into `SimplePredSpec`, which directly stores a `PredType`, and `SubTypePredSpec`, which stores the actual and expected types in a subtype check. `SubTypePredSpec` is only used for `DeriveAnyClass`; all other deriving strategies use `SimplePredSpec`. * Because `tcSubTypeSigma` manages the finer details of type variable instantiation and constraint solving under the hood, there is no longer any need to delicately split apart the method type signatures in `inferConstraintsAnyclass`. This greatly simplifies the implementation of `inferConstraintsAnyclass` and obviates the need to store skolems, metavariables, or given constraints in a `ThetaSpec` (previously named `ThetaOrigin`). As a bonus, this means that `ThetaSpec` now simply becomes a synonym for a list of `PredSpec`s, which is conceptually much simpler than it was before. * In `simplifyDeriv`, each `SubTypePredSpec` results in a call to `tcSubTypeSigma`. This is only performed for its side effect of emitting an implication constraint, which is fed to the rest of the constraint solving machinery in `simplifyDeriv`. I have updated `Note [Gathering and simplifying constraints for DeriveAnyClass]` to explain this in more detail. To make the changes in `simplifyDeriv` more manageable, I also performed some auxiliary refactoring: * Previously, every iteration of `simplifyDeriv` was skolemising the type variables at the start, simplifying, and then performing a reverse substitution at the end to un-skolemise the type variables. This is not necessary, however, since we can just as well skolemise once at the beginning of the `deriving` pipeline and zonk the `TcTyVar`s after `simplifyDeriv` is finished. This patch does just that, having been made possible by prior work in !7613. I have updated `Note [Overlap and deriving]` in `GHC.Tc.Deriv.Infer` to explain this, and I have also left comments on the relevant data structures (e.g., `DerivEnv` and `DerivSpec`) to explain when things might be `TcTyVar`s or `TyVar`s. * All of the aforementioned cleanup allowed me to remove an ad hoc deriving-related in `checkImplicationInvariants`, as all of the skolems in a `tcSubTypeSigma`–produced implication constraint should now be `TcTyVar` at the time the implication is created. * Since `simplifyDeriv` now needs a `SkolemInfo` and `UserTypeCtxt`, I have added `ds_skol_info` and `ds_user_ctxt` fields to `DerivSpec` to store these. Similarly, I have also added a `denv_skol_info` field to `DerivEnv`, which ultimately gets used to initialize the `ds_skol_info` in a `DerivSpec`. Fixes #20719.
* Fix isLiftedType_maybe and handle falloutsheaf2022-03-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As #20837 pointed out, `isLiftedType_maybe` returned `Just False` in many situations where it should return `Nothing`, because it didn't take into account type families or type variables. In this patch, we fix this issue. We rename `isLiftedType_maybe` to `typeLevity_maybe`, which now returns a `Levity` instead of a boolean. We now return `Nothing` for types with kinds of the form `TYPE (F a1 ... an)` for a type family `F`, as well as `TYPE (BoxedRep l)` where `l` is a type variable. This fix caused several other problems, as other parts of the compiler were relying on `isLiftedType_maybe` returning a `Just` value, and were now panicking after the above fix. There were two main situations in which panics occurred: 1. Issues involving the let/app invariant. To uphold that invariant, we need to know whether something is lifted or not. If we get an answer of `Nothing` from `isLiftedType_maybe`, then we don't know what to do. As this invariant isn't particularly invariant, we can change the affected functions to not panic, e.g. by behaving the same in the `Just False` case and in the `Nothing` case (meaning: no observable change in behaviour compared to before). 2. Typechecking of data (/newtype) constructor patterns. Some programs involving patterns with unknown representations were accepted, such as T20363. Now that we are stricter, this caused further issues, culminating in Core Lint errors. However, the behaviour was incorrect the whole time; the incorrectness only being revealed by this change, not triggered by it. This patch fixes this by overhauling where the representation polymorphism involving pattern matching are done. Instead of doing it in `tcMatches`, we instead ensure that the `matchExpected` functions such as `matchExpectedFunTys`, `matchActualFunTySigma`, `matchActualFunTysRho` allow return argument pattern types which have a fixed RuntimeRep (as defined in Note [Fixed RuntimeRep]). This ensures that the pattern matching code only ever handles types with a known runtime representation. One exception was that patterns with an unknown representation type could sneak in via `tcConPat`, which points to a missing representation-polymorphism check, which this patch now adds. This means that we now reject the program in #20363, at least until we implement PHASE 2 of FixedRuntimeRep (allowing type families in RuntimeRep positions). The aforementioned refactoring, in which checks have been moved to `matchExpected` functions, is a first step in implementing PHASE 2 for patterns. Fixes #20837
* Refactor tcDeriving to generate tyfam insts before any bindingsRyan Scott2022-03-111-68/+110
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously, there was an awful hack in `genInst` (now called `genInstBinds` after this patch) where we had to return a continutation rather than directly returning the bindings for a derived instance. This was done for staging purposes, as we had to first infer the instance contexts for derived instances and then feed these contexts into the continuations to ensure the generated instance bindings had accurate instance contexts. `Note [Staging of tcDeriving]` in `GHC.Tc.Deriving` described this confusing state of affairs. The root cause of this confusing design was the fact that `genInst` was trying to generate instance bindings and associated type family instances for derived instances simultaneously. This really isn't possible, however: as `Note [Staging of tcDeriving]` explains, one needs to have access to the associated type family instances before one can properly infer the instance contexts for derived instances. The use of continuation-returning style was an attempt to circumvent this dependency, but it did so in an awkward way. This patch detangles this awkwardness by splitting up `genInst` into two functions: `genFamInsts` (for associated type family instances) and `genInstBinds` (for instance bindings). Now, the `tcDeriving` function calls `genFamInsts` and brings all the family instances into scope before calling `genInstBinds`. This removes the need for the awkward continuation-returning style seen in the previous version of `genInst`, making the code easier to understand. There are some knock-on changes as well: 1. `hasStockDeriving` now needs to return two separate functions: one that describes how to generate family instances for a stock-derived instance, and another that describes how to generate the instance bindings. I factored out this pattern into a new `StockGenFns` data type. 2. While documenting `StockGenFns`, I realized that there was some inconsistency regarding which `StockGenFns` functions needed which arguments. In particular, the function in `GHC.Tc.Deriv.Generics` which generates `Rep(1)` instances did not take a `SrcSpan` like other `gen_*` functions did, and it included an extra `[Type]` argument that was entirely redundant. As a consequence, I refactored the code in `GHC.Tc.Deriv.Generics` to more closely resemble other `gen_*` functions. A happy result of all this is that all `StockGenFns` functions now take exactly the same arguments, which makes everything more uniform. This is purely a refactoring that should not have any effect on user-observable behavior. The new design paves the way for an eventual fix for #20719.
* Fix some notesMatthew Pickering2022-02-081-1/+1
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* Rework the handling of SkolemInfoMatthew Pickering2022-01-291-3/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The main purpose of this patch is to attach a SkolemInfo directly to each SkolemTv. This fixes the large number of bugs which have accumulated over the years where we failed to report errors due to having "no skolem info" for particular type variables. Now the origin of each type varible is stored on the type variable we can always report accurately where it cames from. Fixes #20969 #20732 #20680 #19482 #20232 #19752 #10946 #19760 #20063 #13499 #14040 The main changes of this patch are: * SkolemTv now contains a SkolemInfo field which tells us how the SkolemTv was created. Used when reporting errors. * Enforce invariants relating the SkolemInfoAnon and level of an implication (ic_info, ic_tclvl) to the SkolemInfo and level of the type variables in ic_skols. * All ic_skols are TcTyVars -- Check is currently disabled * All ic_skols are SkolemTv * The tv_lvl of the ic_skols agrees with the ic_tclvl * The ic_info agrees with the SkolInfo of the implication. These invariants are checked by a debug compiler by checkImplicationInvariants. * Completely refactor kcCheckDeclHeader_sig which kept doing my head in. Plus, it wasn't right because it wasn't skolemising the binders as it decomposed the kind signature. The new story is described in Note [kcCheckDeclHeader_sig]. The code is considerably shorter than before (roughly 240 lines turns into 150 lines). It still has the same awkward complexity around computing arity as before, but that is a language design issue. See Note [Arity inference in kcCheckDeclHeader_sig] * I added new type synonyms MonoTcTyCon and PolyTcTyCon, and used them to be clear which TcTyCons have "finished" kinds etc, and which are monomorphic. See Note [TcTyCon, MonoTcTyCon, and PolyTcTyCon] * I renamed etaExpandAlgTyCon to splitTyConKind, becuase that's a better name, and it is very useful in kcCheckDeclHeader_sig, where eta-expansion isn't an issue. * Kill off the nasty `ClassScopedTvEnv` entirely. Co-authored-by: Simon Peyton Jones <simon.peytonjones@gmail.com>
* DeriveGeneric: look up datacon fixities using getDataConFixityFunRyan Scott2022-01-251-3/+5
| | | | | | | | | | | | Previously, `DeriveGeneric` would look up the fixity of a data constructor using `getFixityEnv`, but this is subtly incorrect for data constructors defined in external modules. This sort of situation can happen with `StandaloneDeriving`, as noticed in #20994. In fact, the same bug has occurred in the past in #9830, and while that bug was fixed for `deriving Read` and `deriving Show`, the fix was never extended to `DeriveGeneric` due to an oversight. This patch corrects that oversight. Fixes #20994.
* Instantiate field types properly in stock-derived instancesRyan Scott2021-11-151-38/+43
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously, the `deriving` machinery was very loosey-goosey about how it used the types of data constructor fields when generating code. It would usually just consult `dataConOrigArgTys`, which returns the _uninstantiated_ field types of each data constructor. Usually, you can get away with this, but issues #20375 and #20387 revealed circumstances where this approach fails. Instead, when generated code for a stock-derived instance `C (T arg_1 ... arg_n)`, one must take care to instantiate the field types of each data constructor with `arg_1 ... arg_n`. The particulars of how this is accomplished is described in the new `Note [Instantiating field types in stock deriving]` in `GHC.Tc.Deriv.Generate`. Some highlights: * `DerivInstTys` now has a new `dit_dc_inst_arg_env :: DataConEnv [Type]` field that caches the instantiated field types of each data constructor. Whenever we need to consult the field types somewhere in `GHC.Tc.Deriv.*` we avoid using `dataConOrigArgTys` and instead look it up in `dit_dc_inst_arg_env`. * Because `DerivInstTys` now stores the instantiated field types of each constructor, some of the details of the `GHC.Tc.Deriv.Generics.mkBindsRep` function were able to be simplified. In particular, we no longer need to apply a substitution to instantiate the field types in a `Rep(1)` instance, as that is already done for us by `DerivInstTys`. We still need a substitution to implement the "wrinkle" section of `Note [Generating a correctly typed Rep instance]`, but the code is nevertheless much simpler than before. * The `tyConInstArgTys` function has been removed in favor of the new `GHC.Core.DataCon.dataConInstUnivs` function, which is really the proper tool for the job. `dataConInstUnivs` is much like `tyConInstArgTys` except that it takes a data constructor, not a type constructor, as an argument, and it adds extra universal type variables from that data constructor at the end of the returned list if need be. `dataConInstUnivs` takes care to instantiate the kinds of the universal type variables at the end, thereby avoiding a bug in `tyConInstArgTys` discovered in https://gitlab.haskell.org/ghc/ghc/-/issues/20387#note_377037. Fixes #20375. Fixes #20387.
* Refactoring: Consolidate some arguments with DerivInstTysRyan Scott2021-11-151-73/+40
| | | | | | | | | | | Various functions in GHC.Tc.Deriv.* were passing around `TyCon`s and `[Type]`s that ultimately come from the same `DerivInstTys`. This patch moves the definition of `DerivInstTys` to `GHC.Tc.Deriv.Generate` so that all of these `TyCon` and `[Type]` arguments can be consolidated into a single `DerivInstTys`. Not only does this make the code easier to read (in my opinion), this will also be important in a subsequent commit where we need to add another field to `DerivInstTys` that will also be used from `GHC.Tc.Deriv.Generate` and friends.
* Flesh out Note [The stupid context] and reference itRyan Scott2021-11-091-0/+3
| | | | | | `Note [The stupid context]` in `GHC.Core.DataCon` talks about stupid contexts from `DatatypeContexts`, but prior to this commit, it was rather outdated. This commit spruces it up and references it from places where it is relevant.
* Eradicate TcRnUnknownMessage from GHC.Tc.DerivAlfredo Di Napoli2021-10-051-87/+62
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This (big) commit finishes porting the GHC.Tc.Deriv module to support the new diagnostic infrastructure (#18516) by getting rid of the legacy calls to `TcRnUnknownMessage`. This work ended up being quite pervasive and touched not only the Tc.Deriv module but also the Tc.Deriv.Utils and Tc.Deriv.Generics module, which needed to be adapted to use the new infrastructure. This also required generalising `Validity`. More specifically, this is a breakdown of the work done: * Add and use the TcRnUselessTypeable data constructor * Add and use TcRnDerivingDefaults data constructor * Add and use the TcRnNonUnaryTypeclassConstraint data constructor * Add and use TcRnPartialTypeSignatures * Add T13324_compile2 test to test another part of the TcRnPartialTypeSignatures diagnostic * Add and use TcRnCannotDeriveInstance data constructor, which introduces a new data constructor to TcRnMessage called TcRnCannotDeriveInstance, which is further sub-divided to carry a `DeriveInstanceErrReason` which explains the reason why we couldn't derive a typeclass instance. * Add DerivErrSafeHaskellGenericInst data constructor to DeriveInstanceErrReason * Add DerivErrDerivingViaWrongKind and DerivErrNoEtaReduce * Introduce the SuggestExtensionInOrderTo Hint, which adds (and use) a new constructor to the hint type `LanguageExtensionHint` called `SuggestExtensionInOrderTo`, which can be used to give a bit more "firm" recommendations when it's obvious what the required extension is, like in the case for the `DerivingStrategies`, which automatically follows from having enabled both `DeriveAnyClass` and `GeneralizedNewtypeDeriving`. * Wildcard-free pattern matching in mk_eqn_stock, which removes `_` in favour of pattern matching explicitly on `CanDeriveAnyClass` and `NonDerivableClass`, because that determine whether or not we can suggest to the user `DeriveAnyClass` or not.
* Reword: representation instead of levitysheaf2021-06-101-1/+1
| | | | fixes #19756, updates haddock submodule
* GHC Exactprint main commitAlan Zimmerman2021-03-201-3/+3
| | | | | | | | Metric Increase: T10370 parsing001 Updates haddock submodule
* WorkWrap: Unbox constructors with existentials (#18982)Sebastian Graf2020-12-231-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Consider ```hs data Ex where Ex :: e -> Int -> Ex f :: Ex -> Int f (Ex e n) = e `seq` n + 1 ``` Worker/wrapper should build the following worker for `f`: ```hs $wf :: forall e. e -> Int# -> Int# $wf e n = e `seq` n +# 1# ``` But previously it didn't, because `Ex` binds an existential. This patch lifts that condition. That entailed having to instantiate existential binders in `GHC.Core.Opt.WorkWrap.Utils.mkWWstr` via `GHC.Core.Utils.dataConRepFSInstPat`, requiring a bit of a refactoring around what is now `DataConPatContext`. CPR W/W still won't unbox DataCons with existentials. See `Note [Which types are unboxed?]` for details. I also refactored the various `tyCon*DataCon(s)_maybe` functions in `GHC.Core.TyCon`, deleting some of them which are no longer needed (`isDataProductType_maybe` and `isDataSumType_maybe`). I cleaned up a couple of call sites, some of which weren't very explicit about whether they cared for existentials or not. The test output of `T18013` changed, because we now unbox the `Rule` data type. Its constructor carries existential state and will be w/w'd now. In the particular example, the worker functions inlines right back into the wrapper, which then unnecessarily has a (quite big) stable unfolding. I think this kind of fallout is inevitable; see also Note [Don't w/w inline small non-loop-breaker things]. There's a new regression test case `T18982`. Fixes #18982.
* Split GHC.Driver.TypesSylvain Henry2020-10-291-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I was working on making DynFlags stateless (#17957), especially by storing loaded plugins into HscEnv instead of DynFlags. It turned out to be complicated because HscEnv is in GHC.Driver.Types but LoadedPlugin isn't: it is in GHC.Driver.Plugins which depends on GHC.Driver.Types. I didn't feel like introducing yet another hs-boot file to break the loop. Additionally I remember that while we introduced the module hierarchy (#13009) we talked about splitting GHC.Driver.Types because it contained various unrelated types and functions, but we never executed. I didn't feel like making GHC.Driver.Types bigger with more unrelated Plugins related types, so finally I bit the bullet and split GHC.Driver.Types. As a consequence this patch moves a lot of things. I've tried to put them into appropriate modules but nothing is set in stone. Several other things moved to avoid loops. * Removed Binary instances from GHC.Utils.Binary for random compiler things * Moved Typeable Binary instances into GHC.Utils.Binary.Typeable: they import a lot of things that users of GHC.Utils.Binary don't want to depend on. * put everything related to Units/Modules under GHC.Unit: GHC.Unit.Finder, GHC.Unit.Module.{ModGuts,ModIface,Deps,etc.} * Created several modules under GHC.Types: GHC.Types.Fixity, SourceText, etc. * Split GHC.Utils.Error (into GHC.Types.Error) * Finally removed GHC.Driver.Types Note that this patch doesn't put loaded plugins into HscEnv. It's left for another patch. Bump haddock submodule
* Add flags for annotating Generic{,1} methods INLINE[1] (#11068)Andrzej Rybczak2020-10-151-12/+15
| | | | | | | | Makes it possible for GHC to optimize away intermediate Generic representation for more types. Metric Increase: T12227
* Lint the compiler for extraneous LANGUAGE pragmasHécate2020-10-101-4/+3
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* DynFlags: disentangle OutputableSylvain Henry2020-08-121-0/+1
| | | | | | | | | - put panic related functions into GHC.Utils.Panic - put trace related functions using DynFlags in GHC.Driver.Ppr One step closer making Outputable fully independent of DynFlags. Bump haddock submodule
* Pass tc_args to gen_fnBrandon Chinn2020-07-291-6/+6
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* Pass dit_rep_tc_args to dsm_stock_gen_fnBrandon Chinn2020-07-291-7/+10
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* Fix duplicated words and typos in comments and user guideJan Hrček2020-06-281-1/+1
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* Revamp the treatment of auxiliary bindings for derived instancesRyan Scott2020-06-271-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This started as a simple fix for #18321 that organically grew into a much more sweeping refactor of how auxiliary bindings for derived instances are handled. I have rewritten `Note [Auxiliary binders]` in `GHC.Tc.Deriv.Generate` to explain all of the moving parts, but the highlights are: * Previously, the OccName of each auxiliary binding would be given a suffix containing a hash of its package name, module name, and parent data type to avoid name clashes. This was needlessly complicated, so we take the more direct approach of generating `Exact` `RdrName`s for each auxiliary binding with the same `OccName`, but using an underlying `System` `Name` with a fresh `Unique` for each binding. Unlike hashes, allocating new `Unique`s does not require any cleverness and avoid name clashes all the same... * ...speaking of which, in order to convince the renamer that multiple auxiliary bindings with the same `OccName` (but different `Unique`s) are kosher, we now use `rnLocalValBindsLHS` instead of `rnTopBindsLHS` to rename auxiliary bindings. Again, see `Note [Auxiliary binders]` for the full story. * I have removed the `DerivHsBind` constructor for `DerivStuff`—which was only used for `Data.Data`-related auxiliary bindings—and refactored `gen_Data_binds` to use `DerivAuxBind` instead. This brings the treatment of `Data.Data`-related auxiliary bindings in line with every other form of auxiliary binding. Fixes #18321.
* Clean up haddock hyperlinks of GHC.* (part2)Takenobu Tani2020-06-251-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | This updates haddock comments only. This patch focuses to update for hyperlinks in GHC API's haddock comments, because broken links especially discourage newcomers. This includes the following hierarchies: - GHC.Iface.* - GHC.Llvm.* - GHC.Rename.* - GHC.Tc.* - GHC.HsToCore.* - GHC.StgToCmm.* - GHC.CmmToAsm.* - GHC.Runtime.* - GHC.Unit.* - GHC.Utils.* - GHC.SysTools.*
* Linear types (#15981)Krzysztof Gogolewski2020-06-171-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is the first step towards implementation of the linear types proposal (https://github.com/ghc-proposals/ghc-proposals/pull/111). It features * A language extension -XLinearTypes * Syntax for linear functions in the surface language * Linearity checking in Core Lint, enabled with -dlinear-core-lint * Core-to-core passes are mostly compatible with linearity * Fields in a data type can be linear or unrestricted; linear fields have multiplicity-polymorphic constructors. If -XLinearTypes is disabled, the GADT syntax defaults to linear fields The following items are not yet supported: * a # m -> b syntax (only prefix FUN is supported for now) * Full multiplicity inference (multiplicities are really only checked) * Decent linearity error messages * Linear let, where, and case expressions in the surface language (each of these currently introduce the unrestricted variant) * Multiplicity-parametric fields * Syntax for annotating lambda-bound or let-bound with a multiplicity * Syntax for non-linear/multiple-field-multiplicity records * Linear projections for records with a single linear field * Linear pattern synonyms * Multiplicity coercions (test LinearPolyType) A high-level description can be found at https://ghc.haskell.org/trac/ghc/wiki/LinearTypes/Implementation Following the link above you will find a description of the changes made to Core. This commit has been authored by * Richard Eisenberg * Krzysztof Gogolewski * Matthew Pickering * Arnaud Spiwack With contributions from: * Mark Barbone * Alexander Vershilov Updates haddock submodule.
* Unit: split and rename modulesSylvain Henry2020-04-301-1/+1
| | | | | | | Introduce GHC.Unit.* hierarchy for everything concerning units, packages and modules. Update Haddock submodule
* Modules: Utils and Data (#13009)Sylvain Henry2020-04-261-6/+6
| | | | | | | Update Haddock submodule Metric Increase: haddock.compiler
* Modules (#13009)Sylvain Henry2020-04-181-2/+2
| | | | | | | | | | | | | | * SysTools * Parser * GHC.Builtin * GHC.Iface.Recomp * Settings Update Haddock submodule Metric Decrease: Naperian parsing001
* Modules: type-checker (#13009)Sylvain Henry2020-04-071-0/+1111
Update Haddock submodule