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* Convert interface file loading errors into proper diagnosticsMatthew Pickering2023-04-181-1/+14
| | | | | | | | | | | | | | This patch converts all the errors to do with loading interface files into proper structured diagnostics. * DriverMessage: Sometimes in the driver we attempt to load an interface file so we embed the IfaceMessage into the DriverMessage. * TcRnMessage: Most the time we are loading interface files during typechecking, so we embed the IfaceMessage This patch also removes the TcRnInterfaceLookupError constructor which is superceded by the IfaceMessage, which is now structured compared to just storing an SDoc before.
* Handle records in the renamersheaf2023-03-291-6/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch moves the field-based logic for disambiguating record updates to the renamer. The type-directed logic, scheduled for removal, remains in the typechecker. To do this properly (and fix the myriad of bugs surrounding the treatment of duplicate record fields), we took the following main steps: 1. Create GREInfo, a renamer-level equivalent to TyThing which stores information pertinent to the renamer. This allows us to uniformly treat imported and local Names in the renamer, as described in Note [GREInfo]. 2. Remove GreName. Instead of a GlobalRdrElt storing GreNames, which distinguished between normal names and field names, we now store simple Names in GlobalRdrElt, along with the new GREInfo information which allows us to recover the FieldLabel for record fields. 3. Add namespacing for record fields, within the OccNames themselves. This allows us to remove the mangling of duplicate field selectors. This change ensures we don't print mangled names to the user in error messages, and allows us to handle duplicate record fields in Template Haskell. 4. Move record disambiguation to the renamer, and operate on the level of data constructors instead, to handle #21443. The error message text for ambiguous record updates has also been changed to reflect that type-directed disambiguation is on the way out. (3) means that OccEnv is now a bit more complex: we first key on the textual name, which gives an inner map keyed on NameSpace: OccEnv a ~ FastStringEnv (UniqFM NameSpace a) Note that this change, along with (2), both increase the memory residency of GlobalRdrEnv = OccEnv [GlobalRdrElt], which causes a few tests to regress somewhat in compile-time allocation. Even though (3) simplified a lot of code (in particular the treatment of field selectors within Template Haskell and in error messages), it came with one important wrinkle: in the situation of -- M.hs-boot module M where { data A; foo :: A -> Int } -- M.hs module M where { data A = MkA { foo :: Int } } we have that M.hs-boot exports a variable foo, which is supposed to match with the record field foo that M exports. To solve this issue, we add a new impedance-matching binding to M foo{var} = foo{fld} This mimics the logic that existed already for impedance-binding DFunIds, but getting it right was a bit tricky. See Note [Record field impedance matching] in GHC.Tc.Module. We also needed to be careful to avoid introducing space leaks in GHCi. So we dehydrate the GlobalRdrEnv before storing it anywhere, e.g. in ModIface. This means stubbing out all the GREInfo fields, with the function forceGlobalRdrEnv. When we read it back in, we rehydrate with rehydrateGlobalRdrEnv. This robustly avoids any space leaks caused by retaining old type environments. Fixes #13352 #14848 #17381 #17551 #19664 #21443 #21444 #21720 #21898 #21946 #21959 #22125 #22160 #23010 #23062 #23063 Updates haddock submodule ------------------------- Metric Increase: MultiComponentModules MultiLayerModules MultiLayerModulesDefsGhci MultiLayerModulesNoCode T13701 T14697 hard_hole_fits -------------------------
* GHC proposal 496 - Nullary record wildcardsGeorgi Lyubenov2023-02-211-4/+5
| | | | | | | | | | | | | | | | | | | This patch implements GHC proposal 496, which allows record wildcards to be used for nullary constructors, e.g. data A = MkA1 | MkA2 { fld1 :: Int } f :: A -> Int f (MkA1 {..}) = 0 f (MkA2 {..}) = fld1 To achieve this, we add arity information to the record field environment, so that we can accept a constructor which has no fields while continuing to reject non-record constructors with more than 1 field. See Note [Nullary constructors and empty record wildcards], as well as the more general overview in Note [Local constructor info in the renamer], both in the newly introduced GHC.Types.ConInfo module. Fixes #22161
* Minor refactorKrzysztof Gogolewski2023-02-041-2/+2
| | | | | | | | * Introduce refactorDupsOn f = refactorDups (comparing f) * Make mkBigTupleCase and coreCaseTuple monadic. Every call to those functions was preceded by calling newUniqueSupply. * Use mkUserLocalOrCoVar, which is equivalent to combining mkLocalIdOrCoVar with mkInternalName.
* Store RdrName rather than OccName in HolesMatthew Pickering2022-12-241-2/+2
| | | | | | | | | | | | | | | | | In #20472 it was pointed out that you couldn't defer out of scope but the implementation collapsed a RdrName into an OccName to stuff it into a Hole. This leads to the error message for a deferred qualified name dropping the qualification which affects the quality of the error message. This commit adds a bit more structure to a hole, so a hole can replace a RdrName without losing information about what that RdrName was. This is important when printing error messages. I also added a test which checks the Template Haskell deferral of out of scope qualified names works properly. Fixes #22130
* Print unticked promoted data constructors (#20531)Vladislav Zavialov2022-11-251-16/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Before this patch, GHC unconditionally printed ticks before promoted data constructors: ghci> type T = True -- unticked (user-written) ghci> :kind! T T :: Bool = 'True -- ticked (compiler output) After this patch, GHC prints ticks only when necessary: ghci> type F = False -- unticked (user-written) ghci> :kind! F F :: Bool = False -- unticked (compiler output) ghci> data False -- introduce ambiguity ghci> :kind! F F :: Bool = 'False -- ticked by necessity (compiler output) The old behavior can be enabled by -fprint-redundant-promotion-ticks. Summary of changes: * Rename PrintUnqualified to NamePprCtx * Add QueryPromotionTick to it * Consult the GlobalRdrEnv to decide whether to print a tick (see mkPromTick) * Introduce -fprint-redundant-promotion-ticks Co-authored-by: Artyom Kuznetsov <hi@wzrd.ht>
* Scrub some no-warning pragmas.M Farkas-Dyck2022-11-231-1/+0
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* Minor refactor around FastStringsKrzysztof Gogolewski2022-11-051-1/+1
| | | | | | | Pass FastStrings to functions directly, to make sure the rule for fsLit "literal" fires. Remove SDoc indirection in GHCi.UI.Tags and GHC.Unit.Module.Graph.
* Allow configuration of error message printingMatthew Pickering2022-10-181-8/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This MR implements the idea of #21731 that the printing of a diagnostic method should be configurable at the printing time. The interface of the `Diagnostic` class is modified from: ``` class Diagnostic a where diagnosticMessage :: a -> DecoratedSDoc diagnosticReason :: a -> DiagnosticReason diagnosticHints :: a -> [GhcHint] ``` to ``` class Diagnostic a where type DiagnosticOpts a defaultDiagnosticOpts :: DiagnosticOpts a diagnosticMessage :: DiagnosticOpts a -> a -> DecoratedSDoc diagnosticReason :: a -> DiagnosticReason diagnosticHints :: a -> [GhcHint] ``` and so each `Diagnostic` can implement their own configuration record which can then be supplied by a client in order to dictate how to print out the error message. At the moment this only allows us to implement #21722 nicely but in future it is more natural to separate the configuration of how much information we put into an error message and how much we decide to print out of it. Updates Haddock submodule
* Fix typosEric Lindblad2022-09-141-2/+2
| | | | | | | This fixes various typos and spelling mistakes in the compiler. Fixes #21891
* Fix unification of ConcreteTvs, removing IsRefl#sheaf2022-04-281-1/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch fixes the unification of concrete type variables. The subtlety was that unifying concrete metavariables is more subtle than other metavariables, as decomposition is possible. See the Note [Unifying concrete metavariables], which explains how we unify a concrete type variable with a type 'ty' by concretising 'ty', using the function 'GHC.Tc.Utils.Concrete.concretise'. This can be used to perform an eager syntactic check for concreteness, allowing us to remove the IsRefl# special predicate. Instead of emitting two constraints `rr ~# concrete_tv` and `IsRefl# rr concrete_tv`, we instead concretise 'rr'. If this succeeds we can fill 'concrete_tv', and otherwise we directly emit an error message to the typechecker environment instead of deferring. We still need the error message to be passed on (instead of directly thrown), as we might benefit from further unification in which case we will need to zonk the stored types. To achieve this, we change the 'wc_holes' field of 'WantedConstraints' to 'wc_errors', which stores general delayed errors. For the moement, a delayed error is either a hole, or a syntactic equality error. hasFixedRuntimeRep_MustBeRefl is now hasFixedRuntimeRep_syntactic, and hasFixedRuntimeRep has been refactored to directly return the most useful coercion for PHASE 2 of FixedRuntimeRep. This patch also adds a field ir_frr to the InferResult datatype, holding a value of type Maybe FRROrigin. When this value is not Nothing, this means that we must fill the ir_ref field with a type which has a fixed RuntimeRep. When it comes time to fill such an ExpType, we ensure that the type has a fixed RuntimeRep by performing a representation-polymorphism check with the given FRROrigin This is similar to what we already do to ensure we fill an Infer ExpType with a type of the correct TcLevel. This allows us to properly perform representation-polymorphism checks on 'Infer' 'ExpTypes'. The fillInferResult function had to be moved to GHC.Tc.Utils.Unify to avoid a cyclic import now that it calls hasFixedRuntimeRep. This patch also changes the code in matchExpectedFunTys to make use of the coercions, which is now possible thanks to the previous change. This implements PHASE 2 of FixedRuntimeRep in some situations. For example, the test cases T13105 and T17536b are now both accepted. Fixes #21239 and #21325 ------------------------- Metric Decrease: T18223 T5631 -------------------------
* Correctly report SrcLoc of redundant constraintssheaf2022-04-081-1/+1
| | | | | | | | | We were accidentally dropping the source location information in certain circumstances when reporting redundant constraints. This patch makes sure that we set the TcLclEnv correctly before reporting the warning. Fixes #21315
* Make typechecking unfoldings from interfaces lazierMatthew Pickering2022-02-261-20/+10
| | | | | | | | | | | | | The old logic was unecessarily strict in loading unfoldings because when reading the unfolding we would case on the result of attempting to load the template before commiting to which type of unfolding we were producing. Hence trying to inspect any of the information about an unfolding would force the template to be loaded. This also removes a potentially hard to discover bug where if the template failed to be typechecked for some reason then we would just not return an unfolding. Instead we now panic so these bad situations which should never arise can be identified.
* Kill derived constraintsRichard Eisenberg2022-02-231-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Co-authored by: Sam Derbyshire Previously, GHC had three flavours of constraint: Wanted, Given, and Derived. This removes Derived constraints. Though serving a number of purposes, the most important role of Derived constraints was to enable better error messages. This job has been taken over by the new RewriterSets, as explained in Note [Wanteds rewrite wanteds] in GHC.Tc.Types.Constraint. Other knock-on effects: - Various new Notes as I learned about under-described bits of GHC - A reshuffling around the AST for implicit-parameter bindings, with better integration with TTG. - Various improvements around fundeps. These were caused by the fact that, previously, fundep constraints were all Derived, and Derived constraints would get dropped. Thus, an unsolved Derived didn't stop compilation. Without Derived, this is no longer possible, and so we have to be considerably more careful around fundeps. - A nice little refactoring in GHC.Tc.Errors to center the work on a new datatype called ErrorItem. Constraints are converted into ErrorItems at the start of processing, and this allows for a little preprocessing before the main classification. - This commit also cleans up the behavior in generalisation around functional dependencies. Now, if a variable is determined by functional dependencies, it will not be quantified. This change is user facing, but it should trim down GHC's strange behavior around fundeps. - Previously, reportWanteds did quite a bit of work, even on an empty WantedConstraints. This commit adds a fast path. - Now, GHC will unconditionally re-simplify constraints during quantification. See Note [Unconditionally resimplify constraints when quantifying], in GHC.Tc.Solver. Close #18398. Close #18406. Solve the fundep-related non-confluence in #18851. Close #19131. Close #19137. Close #20922. Close #20668. Close #19665. ------------------------- Metric Decrease: LargeRecord T9872b T9872b_defer T9872d TcPlugin_RewritePerf -------------------------
* Track object file dependencies for TH accurately (#20604)Zubin Duggal2022-02-201-7/+15
| | | | | | | | | | | | | | | | | | | `hscCompileCoreExprHook` is changed to return a list of `Module`s required by a splice. These modules are accumulated in the TcGblEnv (tcg_th_needed_mods). Dependencies on the object files of these modules are recording in the interface. The data structures in `LoaderState` are replaced with more efficient versions to keep track of all the information required. The MultiLayerModulesTH_Make allocations increase slightly but runtime is faster. Fixes #20604 ------------------------- Metric Increase: MultiLayerModulesTH_Make -------------------------
* Improve errors for non-existent labelsSimon Peyton Jones2022-02-041-1/+1
| | | | | | | | | | | | | | | | This patch fixes #17469, by improving matters when you use non-existent field names in a record construction: data T = MkT { x :: Int } f v = MkT { y = 3 } The check is now made in the renamer, in GHC.Rename.Env.lookupRecFieldOcc. That in turn led to a spurious error in T9975a, which is fixed by making GHC.Rename.Names.extendGlobalRdrEnvRn fail fast if it finds duplicate bindings. See Note [Fail fast on duplicate definitions] in that module for more details. This patch was originated and worked on by Alex D (@nineonine)
* Define and use restoreLclEnvSimon Peyton Jones2022-01-271-29/+67
| | | | | | | | | This fixes #20981. See Note [restoreLclEnv vs setLclEnv] in GHC.Tc.Utils.Monad. I also use updLclEnv rather than get/set when I can, because it's then much clearer that it's an update rather than an entirely new TcLclEnv coming from who-knows-where.
* Multiple Home UnitsMatthew Pickering2021-12-281-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Multiple home units allows you to load different packages which may depend on each other into one GHC session. This will allow both GHCi and HLS to support multi component projects more naturally. Public Interface ~~~~~~~~~~~~~~~~ In order to specify multiple units, the -unit @⟨filename⟩ flag is given multiple times with a response file containing the arguments for each unit. The response file contains a newline separated list of arguments. ``` ghc -unit @unitLibCore -unit @unitLib ``` where the `unitLibCore` response file contains the normal arguments that cabal would pass to `--make` mode. ``` -this-unit-id lib-core-0.1.0.0 -i -isrc LibCore.Utils LibCore.Types ``` The response file for lib, can specify a dependency on lib-core, so then modules in lib can use modules from lib-core. ``` -this-unit-id lib-0.1.0.0 -package-id lib-core-0.1.0.0 -i -isrc Lib.Parse Lib.Render ``` Then when the compiler starts in --make mode it will compile both units lib and lib-core. There is also very basic support for multiple home units in GHCi, at the moment you can start a GHCi session with multiple units but only the :reload is supported. Most commands in GHCi assume a single home unit, and so it is additional work to work out how to modify the interface to support multiple loaded home units. Options used when working with Multiple Home Units There are a few extra flags which have been introduced specifically for working with multiple home units. The flags allow a home unit to pretend it’s more like an installed package, for example, specifying the package name, module visibility and reexported modules. -working-dir ⟨dir⟩ It is common to assume that a package is compiled in the directory where its cabal file resides. Thus, all paths used in the compiler are assumed to be relative to this directory. When there are multiple home units the compiler is often not operating in the standard directory and instead where the cabal.project file is located. In this case the -working-dir option can be passed which specifies the path from the current directory to the directory the unit assumes to be it’s root, normally the directory which contains the cabal file. When the flag is passed, any relative paths used by the compiler are offset by the working directory. Notably this includes -i and -I⟨dir⟩ flags. -this-package-name ⟨name⟩ This flag papers over the awkward interaction of the PackageImports and multiple home units. When using PackageImports you can specify the name of the package in an import to disambiguate between modules which appear in multiple packages with the same name. This flag allows a home unit to be given a package name so that you can also disambiguate between multiple home units which provide modules with the same name. -hidden-module ⟨module name⟩ This flag can be supplied multiple times in order to specify which modules in a home unit should not be visible outside of the unit it belongs to. The main use of this flag is to be able to recreate the difference between an exposed and hidden module for installed packages. -reexported-module ⟨module name⟩ This flag can be supplied multiple times in order to specify which modules are not defined in a unit but should be reexported. The effect is that other units will see this module as if it was defined in this unit. The use of this flag is to be able to replicate the reexported modules feature of packages with multiple home units. Offsetting Paths in Template Haskell splices ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ When using Template Haskell to embed files into your program, traditionally the paths have been interpreted relative to the directory where the .cabal file resides. This causes problems for multiple home units as we are compiling many different libraries at once which have .cabal files in different directories. For this purpose we have introduced a way to query the value of the -working-dir flag to the Template Haskell API. By using this function we can implement a makeRelativeToProject function which offsets a path which is relative to the original project root by the value of -working-dir. ``` import Language.Haskell.TH.Syntax ( makeRelativeToProject ) foo = $(makeRelativeToProject "./relative/path" >>= embedFile) ``` > If you write a relative path in a Template Haskell splice you should use the makeRelativeToProject function so that your library works correctly with multiple home units. A similar function already exists in the file-embed library. The function in template-haskell implements this function in a more robust manner by honouring the -working-dir flag rather than searching the file system. Closure Property for Home Units ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For tools or libraries using the API there is one very important closure property which must be adhered to: > Any dependency which is not a home unit must not (transitively) depend on a home unit. For example, if you have three packages p, q and r, then if p depends on q which depends on r then it is illegal to load both p and r as home units but not q, because q is a dependency of the home unit p which depends on another home unit r. If you are using GHC by the command line then this property is checked, but if you are using the API then you need to check this property yourself. If you get it wrong you will probably get some very confusing errors about overlapping instances. Limitations of Multiple Home Units ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ There are a few limitations of the initial implementation which will be smoothed out on user demand. * Package thinning/renaming syntax is not supported * More complicated reexports/renaming are not yet supported. * It’s more common to run into existing linker bugs when loading a large number of packages in a session (for example #20674, #20689) * Backpack is not yet supported when using multiple home units. * Dependency chasing can be quite slow with a large number of modules and packages. * Loading wired-in packages as home units is currently not supported (this only really affects GHC developers attempting to load template-haskell). * Barely any normal GHCi features are supported, it would be good to support enough for ghcid to work correctly. Despite these limitations, the implementation works already for nearly all packages. It has been testing on large dependency closures, including the whole of head.hackage which is a total of 4784 modules from 452 packages. Internal Changes ~~~~~~~~~~~~~~~~ * The biggest change is that the HomePackageTable is replaced with the HomeUnitGraph. The HomeUnitGraph is a map from UnitId to HomeUnitEnv, which contains information specific to each home unit. * The HomeUnitEnv contains: - A unit state, each home unit can have different package db flags - A set of dynflags, each home unit can have different flags - A HomePackageTable * LinkNode: A new node type is added to the ModuleGraph, this is used to place the linking step into the build plan so linking can proceed in parralel with other packages being built. * New invariant: Dependencies of a ModuleGraphNode can be completely determined by looking at the value of the node. In order to achieve this, downsweep now performs a more complete job of downsweeping and then the dependenices are recorded forever in the node rather than being computed again from the ModSummary. * Some transitive module calculations are rewritten to use the ModuleGraph which is more efficient. * There is always an active home unit, which simplifies modifying a lot of the existing API code which is unit agnostic (for example, in the driver). The road may be bumpy for a little while after this change but the basics are well-tested. One small metric increase, which we accept and also submodule update to haddock which removes ExtendedModSummary. Closes #10827 ------------------------- Metric Increase: MultiLayerModules ------------------------- Co-authored-by: Fendor <power.walross@gmail.com>
* More support for optional home-unitSylvain Henry2021-11-201-4/+4
| | | | | | | | | This is a preliminary refactoring for #14335 (supporting plugins in cross-compilers). In many places the home-unit must be optional because there won't be one available in the plugin environment (we won't be compiling anything in this environment). Hence we replace "HomeUnit" with "Maybe HomeUnit" in a few places and we avoid the use of "hsc_home_unit" (which is partial) in some few others.
* Generalize the type of wrapLocSndMAVladislav Zavialov2021-11-031-4/+13
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* EPA: Get rid of bare SrcSpan's in the ParsedSourceAlan Zimmerman2021-11-021-1/+1
| | | | | | | | | | | | | The ghc-exactPrint library has had to re-introduce the relatavise phase. This is needed if you change the length of an identifier and want the layout to be preserved afterwards. It is not possible to relatavise a bare SrcSpan, so introduce `SrcAnn NoEpAnns` for them instead. Updates haddock submodule.
* Be more careful about retaining KnotVarsMatthew Pickering2021-10-121-1/+1
| | | | | | | | | | | | | | | | | | | | | It is quite easy to end up accidently retaining a KnotVars, which contains pointers to a stale TypeEnv because they are placed in the HscEnv. One place in particular we have to be careful is when loading a module into the EPS in `--make` mode, we have to remove the reference to KnotVars as otherwise the interface loading thunks will forever retain reference to the KnotVars which are live at the time the interface was loaded. These changes do not go as far as to enforce the invariant described in Note [KnotVar invariants] * At the end of upsweep, there should be no live KnotVars but at least improve the situation. This is left for future work (#20491)
* Add defaulting plugins.Andrei Barbu2021-10-081-0/+1
| | | | | | | | | | | | | | | Like the built-in type defaulting rules these plugins can propose candidates to resolve ambiguous type variables. Machine learning and other large APIs like those for game engines introduce new numeric types and other complex typed APIs. The built-in defaulting mechanism isn't powerful enough to resolve ambiguous types in these cases forcing users to specify minutia that they might not even know how to do. There is an example defaulting plugin linked in the documentation. Applications include defaulting the device a computation executes on, if a gradient should be computed for a tensor, or the size of a tensor. See https://github.com/ghc-proposals/ghc-proposals/pull/396 for details.
* Driver rework pt3: the upsweepMatthew Pickering2021-08-181-18/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch specifies and simplifies the module cycle compilation in upsweep. How things work are described in the Note [Upsweep] Note [Upsweep] ~~~~~~~~~~~~~~ Upsweep takes a 'ModuleGraph' as input, computes a build plan and then executes the plan in order to compile the project. The first step is computing the build plan from a 'ModuleGraph'. The output of this step is a `[BuildPlan]`, which is a topologically sorted plan for how to build all the modules. ``` data BuildPlan = SingleModule ModuleGraphNode -- A simple, single module all alone but *might* have an hs-boot file which isn't part of a cycle | ResolvedCycle [ModuleGraphNode] -- A resolved cycle, linearised by hs-boot files | UnresolvedCycle [ModuleGraphNode] -- An actual cycle, which wasn't resolved by hs-boot files ``` The plan is computed in two steps: Step 1: Topologically sort the module graph without hs-boot files. This returns a [SCC ModuleGraphNode] which contains cycles. Step 2: For each cycle, topologically sort the modules in the cycle *with* the relevant hs-boot files. This should result in an acyclic build plan if the hs-boot files are sufficient to resolve the cycle. The `[BuildPlan]` is then interpreted by the `interpretBuildPlan` function. * `SingleModule nodes` are compiled normally by either the upsweep_inst or upsweep_mod functions. * `ResolvedCycles` need to compiled "together" so that the information which ends up in the interface files at the end is accurate (and doesn't contain temporary information from the hs-boot files.) - During the initial compilation, a `KnotVars` is created which stores an IORef TypeEnv for each module of the loop. These IORefs are gradually updated as the loop completes and provide the required laziness to typecheck the module loop. - At the end of typechecking, all the interface files are typechecked again in the retypecheck loop. This time, the knot-tying is done by the normal laziness based tying, so the environment is run without the KnotVars. * UnresolvedCycles are indicative of a proper cycle, unresolved by hs-boot files and are reported as an error to the user. The main trickiness of `interpretBuildPlan` is deciding which version of a dependency is visible from each module. For modules which are not in a cycle, there is just one version of a module, so that is always used. For modules in a cycle, there are two versions of 'HomeModInfo'. 1. Internal to loop: The version created whilst compiling the loop by upsweep_mod. 2. External to loop: The knot-tied version created by typecheckLoop. Whilst compiling a module inside the loop, we need to use the (1). For a module which is outside of the loop which depends on something from in the loop, the (2) version is used. As the plan is interpreted, which version of a HomeModInfo is visible is updated by updating a map held in a state monad. So after a loop has finished being compiled, the visible module is the one created by typecheckLoop and the internal version is not used again. This plan also ensures the most important invariant to do with module loops: > If you depend on anything within a module loop, before you can use the dependency, the whole loop has to finish compiling. The end result of `interpretBuildPlan` is a `[MakeAction]`, which are pairs of `IO a` actions and a `MVar (Maybe a)`, somewhere to put the result of running the action. This list is topologically sorted, so can be run in order to compute the whole graph. As well as this `interpretBuildPlan` also outputs an `IO [Maybe (Maybe HomeModInfo)]` which can be queried at the end to get the result of all modules at the end, with their proper visibility. For example, if any module in a loop fails then all modules in that loop will report as failed because the visible node at the end will be the result of retypechecking those modules together. Along the way we also fix a number of other bugs in the driver: * Unify upsweep and parUpsweep. * Fix #19937 (static points, ghci and -j) * Adds lots of module loop tests due to Divam. Also related to #20030 Co-authored-by: Divam Narula <dfordivam@gmail.com> ------------------------- Metric Decrease: T10370 -------------------------
* Add rewriting to typechecking pluginssheaf2021-08-131-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | Type-checking plugins can now directly rewrite type-families. The TcPlugin record is given a new field, tcPluginRewrite. The plugin specifies how to rewrite certain type-families with a value of type `UniqFM TyCon TcPluginRewriter`, where: type TcPluginRewriter = RewriteEnv -- Rewriter environment -> [Ct] -- Givens -> [TcType] -- type family arguments -> TcPluginM TcPluginRewriteResult data TcPluginRewriteResult = TcPluginNoRewrite | TcPluginRewriteTo { tcPluginRewriteTo :: Reduction , tcRewriterNewWanteds :: [Ct] } When rewriting an exactly-saturated type-family application, GHC will first query type-checking plugins for possible rewritings before proceeding. Includes some changes to the TcPlugin API, e.g. removal of the EvBindsVar parameter to the TcPluginM monad.
* Inline less logging codeSimon Peyton Jones2021-07-281-23/+35
| | | | | | | | | | | | When eyeballing calls of GHC.Core.Opt.Simplify.Monad.traceSmpl, I saw that lots of cold-path logging code was getting inlined into the main Simplifier module. So in GHC.Utils.Logger I added a NOINLINE on logDumpFile'. For logging, the "hot" path, up to and including the conditional, should be inlined, but after that we should inline as little as possible, to reduce code size in the caller.
* Dynflags: introduce DiagOptsSylvain Henry2021-07-011-4/+5
| | | | | | | | | | | | | | | | | | | | | | Use DiagOpts for diagnostic options instead of directly querying DynFlags (#17957). Surprising performance improvements on CI: T4801(normal) ghc/alloc 313236344.0 306515216.0 -2.1% GOOD T9961(normal) ghc/alloc 384502736.0 380584384.0 -1.0% GOOD ManyAlternatives(normal) ghc/alloc 797356128.0 786644928.0 -1.3% ManyConstructors(normal) ghc/alloc 4389732432.0 4317740880.0 -1.6% T783(normal) ghc/alloc 408142680.0 402812176.0 -1.3% Metric Decrease: T4801 T9961 T783 ManyAlternatives ManyConstructors Bump haddock submodule
* Make withException use SDocContext instead of DynFlagsSylvain Henry2021-07-011-4/+3
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* Try to simplify zoo of functions in `Tc.Utils.Monad`Alfredo Di Napoli2021-06-281-97/+76
| | | | | | | | | | | This commit tries to untangle the zoo of diagnostic-related functions in `Tc.Utils.Monad` so that we can have the interfaces mentions only `TcRnMessage`s while we push the creation of these messages upstream. It also ports TcRnMessage diagnostics to use the new API, in particular this commit switch to use TcRnMessage in the external interfaces of the diagnostic functions, and port the old SDoc to be wrapped into TcRnUnknownMessage.
* Make Logger independent of DynFlagsSylvain Henry2021-06-071-29/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce LogFlags as a independent subset of DynFlags used for logging. As a consequence in many places we don't have to pass both Logger and DynFlags anymore. The main reason for this refactoring is that I want to refactor the systools interfaces: for now many systools functions use DynFlags both to use the Logger and to fetch their parameters (e.g. ldInputs for the linker). I'm interested in refactoring the way they fetch their parameters (i.e. use dedicated XxxOpts data types instead of DynFlags) for #19877. But if I did this refactoring before refactoring the Logger, we would have duplicate parameters (e.g. ldInputs from DynFlags and linkerInputs from LinkerOpts). Hence this patch first. Some flags don't really belong to LogFlags because they are subsystem specific (e.g. most DumpFlags). For example -ddump-asm should better be passed in NCGConfig somehow. This patch doesn't fix this tight coupling: the dump flags are part of the UI but they are passed all the way down for example to infer the file name for the dumps. Because LogFlags are a subset of the DynFlags, we must update the former when the latter changes (not so often). As a consequence we now use accessors to read/write DynFlags in HscEnv instead of using `hsc_dflags` directly. In the process I've also made some subsystems less dependent on DynFlags: - CmmToAsm: by passing some missing flags via NCGConfig (see new fields in GHC.CmmToAsm.Config) - Core.Opt.*: - by passing -dinline-check value into UnfoldingOpts - by fixing some Core passes interfaces (e.g. CallArity, FloatIn) that took DynFlags argument for no good reason. - as a side-effect GHC.Core.Opt.Pipeline.doCorePass is much less convoluted.
* Driver Rework PatchMatthew Pickering2021-06-031-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | This patch comprises of four different but closely related ideas. The net result is fixing a large number of open issues with the driver whilst making it simpler to understand. 1. Use the hash of the source file to determine whether the source file has changed or not. This makes the recompilation checking more robust to modern build systems which are liable to copy files around changing their modification times. 2. Remove the concept of a "stable module", a stable module was one where the object file was older than the source file, and all transitive dependencies were also stable. Now we don't rely on the modification time of the source file, the notion of stability is moot. 3. Fix TH/plugin recompilation after the removal of stable modules. The TH recompilation check used to rely on stable modules. Now there is a uniform and simple way, we directly track the linkables which were loaded into the interpreter whilst compiling a module. This is an over-approximation but more robust wrt package dependencies changing. 4. Fix recompilation checking for dynamic object files. Now we actually check if the dynamic object file exists when compiling with -dynamic-too Fixes #19774 #19771 #19758 #17434 #11556 #9121 #8211 #16495 #7277 #16093
* Introduce Strict.Maybe, Strict.Pair (#19156)Vladislav Zavialov2021-05-231-1/+2
| | | | | | | | | | | | | This patch fixes a space leak related to the use of Maybe in RealSrcSpan by introducing a strict variant of Maybe. In addition to that, it also introduces a strict pair and uses the newly introduced strict data types in a few other places (e.g. the lexer/parser state) to reduce allocations. Includes a regression test.
* Extensible Hints for diagnostic messagesAlfredo Di Napoli2021-05-201-3/+3
| | | | | | | | | | | | | | | | | | This commit extends the GHC diagnostic hierarchy with a `GhcHint` type, modelling helpful suggestions emitted by GHC which can be used to deal with a particular warning or error. As a direct consequence of this, the `Diagnostic` typeclass has been extended with a `diagnosticHints` method, which returns a `[GhcHint]`. This means that now we can clearly separate out the printing of the diagnostic message with the suggested fixes. This is done by extending the `printMessages` function in `GHC.Driver.Errors`. On top of that, the old `PsHint` type has been superseded by the new `GhcHint` type, which de-duplicates some hints in favour of a general `SuggestExtension` constructor that takes a `GHC.LanguageExtensions.Extension`.
* Add some TcRn diagnostic messagesAlfredo Di Napoli2021-05-191-1/+20
| | | | | | | | | | | | | | | | | This commit converts some TcRn diagnostic into proper structured errors. Ported by this commit: * Add TcRnImplicitLift This commit adds the TcRnImplicitLift diagnostic message and a prototype API to be able to log messages which requires additional err info. * Add TcRnUnusedPatternBinds * Add TcRnDodgyExports * Add TcRnDodgyImports message * Add TcRnMissingImportList
* Remove useless {-# LANGUAGE CPP #-} pragmasSylvain Henry2021-05-121-1/+0
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* Fully remove HsVersions.hSylvain Henry2021-05-121-2/+0
| | | | | | | | | | Replace uses of WARN macro with calls to: warnPprTrace :: Bool -> SDoc -> a -> a Remove the now unused HsVersions.h Bump haddock submodule
* Replace CPP assertions with Haskell functionsSylvain Henry2021-05-121-0/+1
| | | | | | | | | | | | | | | There is no reason to use CPP. __LINE__ and __FILE__ macros are now better replaced with GHC's CallStack. As a bonus, assert error messages now contain more information (function name, column). Here is the mapping table (HasCallStack omitted): * ASSERT: assert :: Bool -> a -> a * MASSERT: massert :: Bool -> m () * ASSERTM: assertM :: m Bool -> m () * ASSERT2: assertPpr :: Bool -> SDoc -> a -> a * MASSERT2: massertPpr :: Bool -> SDoc -> m () * ASSERTM2: assertPprM :: m Bool -> SDoc -> m ()
* Add GhcMessage and ancillary typesAlfredo Di Napoli2021-04-291-34/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This commit adds GhcMessage and ancillary (PsMessage, TcRnMessage, ..) types. These types will be expanded to represent more errors generated by different subsystems within GHC. Right now, they are underused, but more will come in the glorious future. See https://gitlab.haskell.org/ghc/ghc/-/wikis/Errors-as-(structured)-values for a design overview. Along the way, lots of other things had to happen: * Adds Semigroup and Monoid instance for Bag * Fixes #19746 by parsing OPTIONS_GHC pragmas into Located Strings. See GHC.Parser.Header.toArgs (moved from GHC.Utils.Misc, where it didn't belong anyway). * Addresses (but does not completely fix) #19709, now reporting desugarer warnings and errors appropriately for TH splices. Not done: reporting type-checker warnings for TH splices. * Some small refactoring around Safe Haskell inference, in order to keep separate classes of messages separate. * Some small refactoring around initDsTc, in order to keep separate classes of messages separate. * Separate out the generation of messages (that is, the construction of the text block) from the wrapping of messages (that is, assigning a SrcSpan). This is more modular than the previous design, which mixed the two. Close #19746. This was a collaborative effort by Alfredo di Napoli and Richard Eisenberg, with a key assist on #19746 by Iavor Diatchki. Metric Increase: MultiLayerModules
* Move 'nextWrapperNum' into 'DsM' and 'TcM'Fendor2021-04-221-1/+3
| | | | | | | | Previously existing in 'DynFlags', 'nextWrapperNum' is a global variable mapping a Module to a number for name generation for FFI calls. This is not the right location for 'nextWrapperNum', as 'DynFlags' should not contain just about any global variable.
* Make updTcRef force the resultMatthew Pickering2021-04-081-2/+1
| | | | | | This can lead to a classic thunk build-up in a TcRef Fixes #19596
* Introduce SevIgnore Severity to suppress warningsAlfredo Di Napoli2021-04-051-3/+2
| | | | | | | | | | | | | | | | | | | | | | This commit introduces a new `Severity` type constructor called `SevIgnore`, which can be used to classify diagnostic messages which are not meant to be displayed to the user, for example suppressed warnings. This extra constructor allows us to get rid of a bunch of redundant checks when emitting diagnostics, typically in the form of the pattern: ``` when (optM Opt_XXX) $ addDiagnosticTc (WarningWithFlag Opt_XXX) ... ``` Fair warning! Not all checks should be omitted/skipped, as evaluating some data structures used to produce a diagnostic might still be expensive (e.g. zonking, etc). Therefore, a case-by-case analysis must be conducted when deciding if a check can be removed or not. Last but not least, we remove the unnecessary `CmdLine.WarnReason` type, which is now redundant with `DiagnosticReason`.
* Compute Severity of diagnostics at birthAlfredo Di Napoli2021-04-011-3/+6
| | | | | | | | | | | | | | | | | | | | | This commit further expand on the design for #18516 by getting rid of the `defaultReasonSeverity` in favour of a function called `diagReasonSeverity` which correctly takes the `DynFlags` as input. The idea is to compute the `Severity` and the `DiagnosticReason` of each message "at birth", without doing any later re-classifications, which are potentially error prone, as the `DynFlags` might evolve during the course of the program. In preparation for a proper refactoring, now `pprWarning` from the Parser.Ppr module has been renamed to `mkParserWarn`, which now takes a `DynFlags` as input. We also get rid of the reclassification we were performing inside `printOrThrowWarnings`. Last but not least, this commit removes the need for reclassify inside GHC.Tc.Errors, and also simplifies the implementation of `maybeReportError`. Update Haddock submodule
* Move the EPS into UnitEnvSylvain Henry2021-04-011-1/+4
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* Encapsulate the EPS IORef in a newtypeSylvain Henry2021-04-011-3/+3
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* Add `MessageClass`, rework `Severity` and add `DiagnosticReason`.wip/adinapoli-message-class-new-designAlfredo Di Napoli2021-03-291-80/+68
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Other than that: * Fix T16167,json,json2,T7478,T10637 tests to reflect the introduction of the `MessageClass` type * Remove `makeIntoWarning` * Remove `warningsToMessages` * Refactor GHC.Tc.Errors 1. Refactors GHC.Tc.Errors so that we use `DiagnosticReason` for "choices" (defer types errors, holes, etc); 2. We get rid of `reportWarning` and `reportError` in favour of a general `reportDiagnostic`. * Introduce `DiagnosticReason`, `Severity` is an enum: This big commit makes `Severity` a simple enumeration, and introduces the concept of `DiagnosticReason`, which classifies the /reason/ why we are emitting a particular diagnostic. It also adds a monomorphic `DiagnosticMessage` type which is used for generic messages. * The `Severity` is computed (for now) from the reason, statically. Later improvement will add a `diagReasonSeverity` function to compute the `Severity` taking `DynFlags` into account. * Rename `logWarnings` into `logDiagnostics` * Add note and expand description of the `mkHoleError` function
* Refactor interface loadingSylvain Henry2021-03-261-15/+7
| | | | | | | | | | In order to support several home-units and several independent unit-databases, it's easier to explicitly pass UnitState, DynFlags, etc. to interface loading functions. This patch converts some functions using monads such as IfG or TcRnIf with implicit access to HscEnv to use IO instead and to pass them specific fields of HscEnv instead of an HscEnv value.
* Implement -Wmissing-kind-signaturesOleg Grenrus2021-03-251-0/+1
| | | | Fixes #19564
* GHC Exactprint main commitAlan Zimmerman2021-03-201-2/+32
| | | | | | | | Metric Increase: T10370 parsing001 Updates haddock submodule
* template-haskell: Add putDoc, getDoc, withDecDoc and friendsLuke Lau2021-03-101-0/+2
| | | | | | | | | | | | | | | | | | | | | | | This adds two new methods to the Quasi class, putDoc and getDoc. They allow Haddock documentation to be added to declarations, module headers, function arguments and class/type family instances, as well as looked up. It works by building up a map of names to attach pieces of documentation to, which are then added in the extractDocs function in GHC.HsToCore.Docs. However because these template haskell names need to be resolved to GHC names at the time they are added, putDoc cannot directly add documentation to declarations that are currently being spliced. To remedy this, withDecDoc/withDecsDoc wraps the operation with addModFinalizer, and provides a more ergonomic interface for doing so. Similarly, the funD_doc, dataD_doc etc. combinators provide a more ergonomic interface for documenting functions and their arguments simultaneously. This also changes ArgDocMap to use an IntMap rather than an Map Int, for efficiency. Part of the work towards #5467
* Fix leaks of the HscEnv with quick flavour (#19356)Sylvain Henry2021-03-031-3/+5
| | | | Thanks @mpickering for finding them!