summaryrefslogtreecommitdiff
path: root/testsuite/tests/indexed-types
Commit message (Collapse)AuthorAgeFilesLines
* driver: Don't create LinkNodes when -no-link is enabledMatthew Pickering2022-07-281-2/+2
| | | | Fixes #21866
* Get the in-scope set right in FamInstEnv.injectiveBranchesSimon Peyton Jones2022-07-253-0/+34
| | | | | | | | | | | | | There was an assert error, as Gergo pointed out in #21896. I fixed this by adding an InScopeSet argument to tcUnifyTyWithTFs. And also to GHC.Core.Unify.niFixTCvSubst. I also took the opportunity to get a couple more InScopeSets right, and to change some substTyUnchecked into substTy. This MR touches a lot of other files, but only because I also took the opportunity to introduce mkInScopeSetList, and use it.
* Implement DeepSubsumptionSimon Peyton Jones2022-07-252-9/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This MR adds the language extension -XDeepSubsumption, implementing GHC proposal #511. This change mitigates the impact of GHC proposal The changes are highly localised, by design. See Note [Deep subsumption] in GHC.Tc.Utils.Unify. The main changes are: * Add -XDeepSubsumption, which is on by default in Haskell98 and Haskell2010, but off in Haskell2021. -XDeepSubsumption largely restores the behaviour before the "simple subsumption" change. -XDeepSubsumpition has a similar flavour as -XNoMonoLocalBinds: it makes type inference more complicated and less predictable, but it may be convenient in practice. * The main changes are in: * GHC.Tc.Utils.Unify.tcSubType, which does deep susumption and eta-expanansion * GHC.Tc.Utils.Unify.tcSkolemiseET, which does deep skolemisation * In GHC.Tc.Gen.App.tcApp we call tcSubTypeNC to match the result type. Without deep subsumption, unifyExpectedType would be sufficent. See Note [Deep subsumption] in GHC.Tc.Utils.Unify. * There are no changes to Quick Look at all. * The type of `withDict` becomes ambiguous; so add -XAllowAmbiguousTypes to GHC.Magic.Dict * I fixed a small but egregious bug in GHC.Core.FVs.varTypeTyCoFVs, where we'd forgotten to take the free vars of the multiplicity of an Id. * I also had to fix tcSplitNestedSigmaTys When I did the shallow-subsumption patch commit 2b792facab46f7cdd09d12e79499f4e0dcd4293f Date: Sun Feb 2 18:23:11 2020 +0000 Simple subsumption I changed tcSplitNestedSigmaTys to not look through function arrows any more. But that was actually an un-forced change. This function is used only in * Improving error messages in GHC.Tc.Gen.Head.addFunResCtxt * Validity checking for default methods: GHC.Tc.TyCl.checkValidClass * A couple of calls in the GHCi debugger: GHC.Runtime.Heap.Inspect All to do with validity checking and error messages. Acutally its fine to look under function arrows here, and quite useful a test DeepSubsumption05 (a test motivated by a build failure in the `lens` package) shows. The fix is easy. I added Note [tcSplitNestedSigmaTys].
* testsuite: Use normalise_version more consistentlyBen Gamari2022-06-271-2/+2
| | | | | Previously several tests' output were unnecessarily dependent on version numbers, particularly of `base`. Fix this.
* Bump ghc-prim and base versionsBen Gamari2022-06-272-2/+2
| | | | | | | | | To 0.9.0 and 4.17.0 respectively. Bumps array, deepseq, directory, filepath, haskeline, hpc, parsec, stm, terminfo, text, unix, haddock, and hsc2hs submodules. (cherry picked from commit ba47b95122b7b336ce1cc00896a47b584ad24095)
* Deprecate TypeInType extensionHaskellMouse2022-06-0619-19/+27
| | | | | | | | | | | | | | | | This commit fixes #20312 It deprecates "TypeInType" extension according to the following proposal: https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0083-no-type-in-type.rst It has been already implemented. The migration strategy: 1. Disable TypeInType 2. Enable both DataKinds and PolyKinds extensions Metric Decrease: T16875
* Generalize breakTyVarCycle to work with TyFamLHSRichard Eisenberg2022-05-261-1/+1
| | | | | | | | | | | | | | | | | The function breakTyVarCycle_maybe has been installed in a dark corner of GHC to catch some gremlins (a.k.a. occurs-check failures) who lurk there. But it previously only caught gremlins of the form (a ~ ... F a ...), where some of our intrepid users have spawned gremlins of the form (G a ~ ... F (G a) ...). This commit improves breakTyVarCycle_maybe (and renames it to breakTyEqCycle_maybe) to catch the new gremlins. Happily, the change is remarkably small. The gory details are in Note [Type equality cycles]. Test cases: typecheck/should_compile/{T21515,T21473}.
* Change GHC.Prim to GHC.Exts in docs and testsKrzysztof Gogolewski2022-04-011-1/+1
| | | | | Users are supposed to import GHC.Exts rather than GHC.Prim. Part of #18749.
* Minor cleanupKrzysztof Gogolewski2022-04-011-2/+0
| | | | | | | | | | | - 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
* Export (~) from Data.Type.Equality (#18862)wip/eqtycon-rnVladislav Zavialov2022-03-154-1/+4
| | | | | | | | | | * Users can define their own (~) type operator * Haddock can display documentation for the built-in (~) * New transitional warnings implemented: -Wtype-equality-out-of-scope -Wtype-equality-requires-operators Updates the haddock submodule.
* Make Constraint not *apart* from Type.Richard Eisenberg2022-03-023-0/+15
| | | | | | More details in Note [coreView vs tcView] Close #21092.
* Kill derived constraintsRichard Eisenberg2022-02-2325-106/+176
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 -------------------------
* Fix some notesMatthew Pickering2022-02-081-1/+1
|
* Make implication tidying agree with Note [Tidying multiple names at once]Matthew Pickering2022-02-052-17/+17
| | | | | | | | | | | Note [Tidying multiple names at once] indicates that if multiple variables have the same name then we shouldn't prioritise one of them and instead rename them all to a1, a2, a3... etc This patch implements that change, some error message changes as expected. Closes #20932
* Rework the handling of SkolemInfoMatthew Pickering2022-01-292-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* Use diagnostic infrastructure in GHC.Tc.Errorssheaf2022-01-178-8/+8
|
* Multiple Home UnitsMatthew Pickering2021-12-281-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* Include "not more specific" info in overlap msgsheaf2021-11-203-15/+17
| | | | | | | | | When instances overlap, we now include additional information about why we weren't able to select an instance: perhaps one instance overlapped another but was not strictly more specific, so we aren't able to directly choose it. Fixes #20542
* Default kind vars in tyfams with -XNoPolyKindssheaf2021-11-083-1/+19
| | | | | | | | | | | | | | | We should still default kind variables in type families in the presence of -XNoPolyKinds, to avoid suggesting enabling -XPolyKinds just because the function arrow introduced kind variables, e.g. type family F (t :: Type) :: Type where F (a -> b) = b With -XNoPolyKinds, we should still default `r :: RuntimeRep` in `a :: TYPE r`. Fixes #20584
* Show family TyCons in mk_dict_error in the case of a single matchZiyang Liu2021-10-294-0/+61
|
* Don't default type variables in type familiessheaf2021-10-263-1/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | This patch removes the following defaulting of type variables in type and data families: - type variables of kind RuntimeRep defaulting to LiftedRep - type variables of kind Levity defaulting to Lifted - type variables of kind Multiplicity defaulting to Many It does this by passing "defaulting options" to the `defaultTyVars` function; when calling from `tcTyFamInstEqnGuts` or `tcDataFamInstHeader` we pass options that avoid defaulting. This avoids wildcards being defaulted, which caused type families to unexpectedly fail to reduce. Note that kind defaulting, applicable only with -XNoPolyKinds, is not changed by this patch. Fixes #17536 ------------------------- Metric Increase: T12227 -------------------------
* Use tcEqType in GHC.Core.Unify.uVarsheaf2021-10-227-0/+54
| | | | | | | | | | | | | | | | | Because uVar used eqType instead of tcEqType, it was possible to accumulate a substitution that unified Type and Constraint. For example, a call to `tc_unify_tys` with arguments tys1 = [ k, k ] tys2 = [ Type, Constraint ] would first add `k = Type` to the substitution. That's fine, but then the second call to `uVar` would claim that the substitution also unifies `k` with `Constraint`. This could then be used to cause trouble, as per #20521. Fixes #20521
* Improve overlap error for polykinded constraintssheaf2021-10-064-2/+28
| | | | | | | | | | | | | | There were two problems around `mkDictErr`: 1. An outdated call to `flattenTys` meant that we missed out on some instances. As we no longer flatten type-family applications, the logic is obsolete and can be removed. 2. We reported "out of scope" errors in a poly-kinded situation because `BoxedRep` and `Lifted` were considered out of scope. We fix this by using `pretendNameIsInScope`. fixes #20465
* Convert diagnostics in GHC.Tc.Validity to proper TcRnMessage.hainq2021-09-011-1/+1
| | | | | | | | | | | | | | | | | | | | - Add 19 new messages. Update test outputs accordingly. - Pretty print suggest-extensions hints: remove space before interspersed commas. - Refactor Rank's MonoType constructors. Each MonoType constructor should represent a specific case. With the Doc suggestion belonging to the TcRnMessage diagnostics instead. - Move Rank from Validity to its own `GHC.Tc.Types.Rank` module. - Remove the outdated `check_irred_pred` check. - Remove the outdated duplication check in `check_valid_theta`, which was subsumed by `redundant-constraints`. - Add missing test cases for quantified-constraints/T16474 & th/T12387a.
* TypeError is OK on the RHS of a type synonymwip/T20181Simon Peyton Jones2021-08-151-3/+21
| | | | | | | | | | We should not complain about TypeError in type T = TypeError blah This fixes #20181 The error message for T13271 changes, because that test did indeed have a type synonym with TypeError on the RHS
* Update expected stderr for affected tests, which are not under Tc directoryCarrieMY2021-07-281-1/+1
|
* Fix #19682 by breaking cycles in DerivedsRichard Eisenberg2021-06-051-4/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This commit expands the old Note [Type variable cycles in Givens] to apply as well to Deriveds. See the Note for details and examples. This fixes a regression introduced by my earlier commit that killed off the flattener in favor of the rewriter. A few other things happened along the way: * unifyTest was renamed to touchabilityTest, because that's what it does. * isInsolubleOccursCheck was folded into checkTypeEq, which does much of the same work. To get this to work out, though, we need to keep more careful track of what errors we spot in checkTypeEq, and so CheckTyEqResult has become rather more glorious. * A redundant Note or two was eliminated. * Kill off occCheckForErrors; due to Note [Rewriting synonyms], the extra occCheckExpand here is always redundant. * Store blocked equalities separately from other inerts; less stuff to look through when kicking out. Close #19682. test case: typecheck/should_compile/T19682{,b}
* Remove transitive information about modules and packages from interface filesMatthew Pickering2021-05-193-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This commit modifies interface files so that *only* direct information about modules and packages is stored in the interface file. * Only direct module and direct package dependencies are stored in the interface files. * Trusted packages are now stored separately as they need to be checked transitively. * hs-boot files below the compiled module in the home module are stored so that eps_is_boot can be calculated in one-shot mode without loading all interface files in the home package. * The transitive closure of signatures is stored separately This is important for two reasons * Less recompilation is needed, as motivated by #16885, a lot of redundant compilation was triggered when adding new imports deep in the module tree as all the parent interface files had to be redundantly updated. * Checking an interface file is cheaper because you don't have to perform a transitive traversal to check the dependencies are up-to-date. In the code, places where we would have used the transitive closure, we instead compute the necessary transitive closure. The closure is not computed very often, was already happening in checkDependencies, and was already happening in getLinkDeps. Fixes #16885 ------------------------- Metric Decrease: MultiLayerModules T13701 T13719 -------------------------
* Always generate ModDetails from ModIfaceMatthew Pickering2021-04-143-18/+18
| | | | | | | | | | | | | | | | | | This vastly reduces memory usage when compiling with `--make` mode, from about 900M when compiling Cabal to about 300M. As a matter of uniformity, it also ensures that reading from an interface performs the same as using the in-memory cache. We can also delete all the horrible knot-tying in updateIdInfos. Goes some way to fixing #13586 Accept new output of tests fixing some bugs along the way ------------------------- Metric Decrease: T12545 -------------------------
* Correct warning for deprecated and unrecognised flagsAlfredo Di Napoli2021-04-052-3/+3
| | | | | | | | | | Fixes #19616. This commit changes the `GHC.Driver.Errors.handleFlagWarnings` function to rely on the newly introduced `DiagnosticReason`. This allows us to correctly pretty-print the flags which triggered some warnings and in turn remove the cruft around this function (like the extra filtering and the `shouldPrintWarning` function.
* Add `MessageClass`, rework `Severity` and add `DiagnosticReason`.wip/adinapoli-message-class-new-designAlfredo Di Napoli2021-03-292-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* GHC Exactprint main commitAlan Zimmerman2021-03-202-2/+2
| | | | | | | | Metric Increase: T10370 parsing001 Updates haddock submodule
* Use GHC2021 as default languageJoachim Breitner2021-03-1067-76/+123
|
* Implement BoxedRep proposalwip/boxed-repBen Gamari2021-03-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | This implements the BoxedRep proposal, refactoring the `RuntimeRep` hierarchy from: ```haskell data RuntimeRep = LiftedPtrRep | UnliftedPtrRep | ... ``` to ```haskell data RuntimeRep = BoxedRep Levity | ... data Levity = Lifted | Unlifted ``` Updates binary, haddock submodules. Closes #17526. Metric Increase: T12545
* Unify result type earlier to improve error messagesSimon Peyton Jones2021-03-017-36/+46
| | | | | | | | | | | | | | | | | | | | | | Ticket #19364 helpfully points out that we do not currently take advantage of pushing the result type of an application into the arguments. This makes error messages notably less good. The fix is rather easy: move the result-type unification step earlier. It's even a bit more efficient; in the the checking case we now do one less zonk. See Note [Unify with expected type before typechecking arguments] in GHC.Tc.Gen.App This change generally improves error messages, but it made one worse: typecheck/should_fail/T16204c. That led me to the realisation that a good error can be replaced by a less-good one, which provoked me to change GHC.Tc.Solver.Interact.inertsCanDischarge. It's explained in the new Note [Combining equalities] One other refactoring: I discovered that KindEqOrigin didn't need a Maybe in its type -- a nice simplification.
* Improve handling of overloaded labels, literals, lists etcwip/T19154Simon Peyton Jones2021-02-192-8/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When implementing Quick Look I'd failed to remember that overloaded labels, like #foo, should be treated as a "head", so that they can be instantiated with Visible Type Application. This caused #19154. A very similar ticket covers overloaded literals: #19167. This patch fixes both problems, but (annoyingly, albeit temporarily) in two different ways. Overloaded labels I dealt with overloaded labels by buying fully into the Rebindable Syntax approach described in GHC.Hs.Expr Note [Rebindable syntax and HsExpansion]. There is a good overview in GHC.Rename.Expr Note [Handling overloaded and rebindable constructs]. That module contains much of the payload for this patch. Specifically: * Overloaded labels are expanded in the renamer, fixing #19154. See Note [Overloaded labels] in GHC.Rename.Expr. * Left and right sections used to have special code paths in the typechecker and desugarer. Now we just expand them in the renamer. This is harder than it sounds. See GHC.Rename.Expr Note [Left and right sections]. * Infix operator applications are expanded in the typechecker, specifically in GHC.Tc.Gen.App.splitHsApps. See Note [Desugar OpApp in the typechecker] in that module * ExplicitLists are expanded in the renamer, when (and only when) OverloadedLists is on. * HsIf is expanded in the renamer when (and only when) RebindableSyntax is on. Reason: the coverage checker treats HsIf specially. Maybe we could instead expand it unconditionally, and fix up the coverage checker, but I did not attempt that. Overloaded literals Overloaded literals, like numbers (3, 4.2) and strings with OverloadedStrings, were not working correctly with explicit type applications (see #19167). Ideally I'd also expand them in the renamer, like the stuff above, but I drew back on that because they can occur in HsPat as well, and I did not want to to do the HsExpanded thing for patterns. But they *can* now be the "head" of an application in the typechecker, and hence something like ("foo" @T) works now. See GHC.Tc.Gen.Head.tcInferOverLit. It's also done a bit more elegantly, rather than by constructing a new HsExpr and re-invoking the typechecker. There is some refactoring around tcShortCutLit. Ultimately there is more to do here, following the Rebindable Syntax story. There are a lot of knock-on effects: * HsOverLabel and ExplicitList no longer need funny (Maybe SyntaxExpr) fields to support rebindable syntax -- good! * HsOverLabel, OpApp, SectionL, SectionR all become impossible in the output of the typecheker, GhcTc; so we set their extension fields to Void. See GHC.Hs.Expr Note [Constructor cannot occur] * Template Haskell quotes for HsExpanded is a bit tricky. See Note [Quotation and rebindable syntax] in GHC.HsToCore.Quote. * In GHC.HsToCore.Match.viewLExprEq, which groups equal HsExprs for the purpose of pattern-match overlap checking, I found that dictionary evidence for the same type could have two different names. Easily fixed by comparing types not names. * I did quite a bit of annoying fiddling around in GHC.Tc.Gen.Head and GHC.Tc.Gen.App to get error message locations and contexts right, esp in splitHsApps, and the HsExprArg type. Tiresome and not very illuminating. But at least the tricky, higher order, Rebuilder function is gone. * Some refactoring in GHC.Tc.Utils.Monad around contexts and locations for rebindable syntax. * Incidentally fixes #19346, because we now print renamed, rather than typechecked, syntax in error mesages about applications. The commit removes the vestigial module GHC.Builtin.RebindableNames, and thus triggers a 2.4% metric decrease for test MultiLayerModules (#19293). Metric Decrease: MultiLayerModules T12545
* Fix a serious bug in roughMatchTcsSimon Peyton Jones2021-02-133-0/+48
| | | | | | | | | | | | | | | | | | | | | | | | | | | The roughMatchTcs function enables a quick definitely-no-match test in lookupInstEnv. Unfortunately, it didn't account for type families. This didn't matter when type families were flattened away, but now they aren't flattened it matters a lot. The fix is very easy. See INVARIANT in GHC.Core.InstEnv Note [ClsInst laziness and the rough-match fields] Fixes #19336 The change makes compiler perf worse on two very-type-family-heavy benchmarks, T9872{a,d}: T9872a(normal) ghc/alloc 2172536442.7 2216337648.0 +2.0% T9872d(normal) ghc/alloc 614584024.0 621081384.0 +1.1% (Everything else is 0.0% or at most 0.1%.) I think we just have to put up with this. Some cases were being wrongly filtered out by roughMatchTcs that might actually match, which could lead to false apartness checks. And it only affects these very type-family-heavy cases. Metric Increase: T9872a T9872d
* Fix typosBrian Wignall2021-02-061-1/+1
|
* Add instances for GHC.Tuple.SoloBen Gamari2021-01-271-1/+1
| | | | | | | | | | | | | | | The `Applicative` instance is the most important one (for array/vector/sequence indexing purposes), but it deserves all the usual ones. T12545 does silly 1% wibbles both ways, it seems, maybe depending on architecture. Metric Increase: T12545 Metric Decrease: T12545
* Never Anyify during kind inferenceRichard Eisenberg2021-01-092-5/+5
| | | | | | | | | See Note [Error on unconstrained meta-variables] in TcMType. Close #17301 Close #17567 Close #17562 Close #15474
* Reject dodgy scoping in associated family instance RHSesRyan Scott2020-12-171-22/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit e63518f5d6a93be111f9108c0990a1162f88d615 tried to push all of the logic of detecting out-of-scope type variables on the RHSes of associated type family instances to `GHC.Tc.Validity` by deleting a similar check in the renamer. Unfortunately, this commit went a little too far, as there are some corner cases that `GHC.Tc.Validity` doesn't detect. Consider this example: ```hs class C a where data D a instance forall a. C Int where data instance D Int = MkD a ``` If this program isn't rejected by the time it reaches the typechecker, then GHC will believe the `a` in `MkD a` is existentially quantified and accept it. This is almost surely not what the user wants! The simplest way to reject programs like this is to restore the old validity check in the renamer (search for `improperly_scoped` in `rnFamEqn`). Note that this is technically a breaking change, since the program in the `polykinds/T9574` test case (which previously compiled) will now be rejected: ```hs instance Funct ('KProxy :: KProxy o) where type Codomain 'KProxy = NatTr (Proxy :: o -> *) ``` This is because the `o` on the RHS will now be rejected for being out of scope. Luckily, this is simple to repair: ```hs instance Funct ('KProxy :: KProxy o) where type Codomain ('KProxy @o) = NatTr (Proxy :: o -> *) ``` All of the discussion is now a part of the revamped `Note [Renaming associated types]` in `GHC.Rename.Module`. A different design would be to make associated type family instances have completely separate scoping from the parent instance declaration, much like how associated type family default declarations work today. See the discussion beginning at https://gitlab.haskell.org/ghc/ghc/-/issues/18021#note_265729 for more on this point. This, however, would break even more programs that are accepted today and likely warrants a GHC proposal before going forward. In the meantime, this patch fixes the issue described in #18021 in the least invasive way possible. There are programs that are accepted today that will no longer be accepted after this patch, but they are arguably pathological programs, and they are simple to repair. Fixes #18021.
* Fix kind inference for data types. Again.Simon Peyton Jones2020-12-085-10/+47
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch fixes several aspects of kind inference for data type declarations, especially data /instance/ declarations Specifically 1. In kcConDecls/kcConDecl make it clear that the tc_res_kind argument is only used in the H98 case; and in that case there is no result kind signature; and hence no need for the disgusting splitPiTys in kcConDecls (now thankfully gone). The GADT case is a bit different to before, and much nicer. This is what fixes #18891. See Note [kcConDecls: kind-checking data type decls] 2. Do not look at the constructor decls of a data/newtype instance in tcDataFamInstanceHeader. See GHC.Tc.TyCl.Instance Note [Kind inference for data family instances]. This was a new realisation that arose when doing (1) This causes a few knock-on effects in the tests suite, because we require more information than before in the instance /header/. New user-manual material about this in "Kind inference in data type declarations" and "Kind inference for data/newtype instance declarations". 3. Minor improvement in kcTyClDecl, combining GADT and H98 cases 4. Fix #14111 and #8707 by allowing the header of a data instance to affect kind inferece for the the data constructor signatures; as described at length in Note [GADT return types] in GHC.Tc.TyCl This led to a modest refactoring of the arguments (and argument order) of tcConDecl/tcConDecls. 5. Fix #19000 by inverting the sense of the test in new_locs in GHC.Tc.Solver.Canonical.canDecomposableTyConAppOK.
* Remove flattening variablesRichard Eisenberg2020-12-0123-63/+166
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch redesigns the flattener to simplify type family applications directly instead of using flattening meta-variables and skolems. The key new innovation is the CanEqLHS type and the new CEqCan constraint (Ct). A CanEqLHS is either a type variable or exactly-saturated type family application; either can now be rewritten using a CEqCan constraint in the inert set. Because the flattener no longer reduces all type family applications to variables, there was some performance degradation if a lengthy type family application is now flattened over and over (not making progress). To compensate, this patch contains some extra optimizations in the flattener, leading to a number of performance improvements. Close #18875. Close #18910. There are many extra parts of the compiler that had to be affected in writing this patch: * The family-application cache (formerly the flat-cache) sometimes stores coercions built from Given inerts. When these inerts get kicked out, we must kick out from the cache as well. (This was, I believe, true previously, but somehow never caused trouble.) Kicking out from the cache requires adding a filterTM function to TrieMap. * This patch obviates the need to distinguish "blocking" coercion holes from non-blocking ones (which, previously, arose from CFunEqCans). There is thus some simplification around coercion holes. * Extra commentary throughout parts of the code I read through, to preserve the knowledge I gained while working. * A change in the pure unifier around unifying skolems with other types. Unifying a skolem now leads to SurelyApart, not MaybeApart, as documented in Note [Binding when looking up instances] in GHC.Core.InstEnv. * Some more use of MCoercion where appropriate. * Previously, class-instance lookup automatically noticed that e.g. C Int was a "unifier" to a target [W] C (F Bool), because the F Bool was flattened to a variable. Now, a little more care must be taken around checking for unifying instances. * Previously, tcSplitTyConApp_maybe would split (Eq a => a). This is silly, because (=>) is not a tycon in Haskell. Fixed now, but there are some knock-on changes in e.g. TrieMap code and in the canonicaliser. * New function anyFreeVarsOf{Type,Co} to check whether a free variable satisfies a certain predicate. * Type synonyms now remember whether or not they are "forgetful"; a forgetful synonym drops at least one argument. This is useful when flattening; see flattenView. * The pattern-match completeness checker invokes the solver. This invocation might need to look through newtypes when checking representational equality. Thus, the desugarer needs to keep track of the in-scope variables to know what newtype constructors are in scope. I bet this bug was around before but never noticed. * Extra-constraints wildcards are no longer simplified before printing. See Note [Do not simplify ConstraintHoles] in GHC.Tc.Solver. * Whether or not there are Given equalities has become slightly subtler. See the new HasGivenEqs datatype. * Note [Type variable cycles in Givens] in GHC.Tc.Solver.Canonical explains a significant new wrinkle in the new approach. * See Note [What might match later?] in GHC.Tc.Solver.Interact, which explains the fix to #18910. * The inert_count field of InertCans wasn't actually used, so I removed it. Though I (Richard) did the implementation, Simon PJ was very involved in design and review. This updates the Haddock submodule to avoid #18932 by adding a type signature. ------------------------- Metric Decrease: T12227 T5030 T9872a T9872b T9872c Metric Increase: T9872d -------------------------
* [Sized Cmm] properly retain sizes.Moritz Angermann2020-11-262-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | This replaces all Word<N> = W<N># Word# and Int<N> = I<N># Int# with Word<N> = W<N># Word<N># and Int<N> = I<N># Int<N>#, thus providing us with properly sized primitives in the codegenerator instead of pretending they are all full machine words. This came up when implementing darwinpcs for arm64. The darwinpcs reqires us to pack function argugments in excess of registers on the stack. While most procedure call standards (pcs) assume arguments are just passed in 8 byte slots; and thus the caller does not know the exact signature to make the call, darwinpcs requires us to adhere to the prototype, and thus have the correct sizes. If we specify CInt in the FFI call, it should correspond to the C int, and not just be Word sized, when it's only half the size. This does change the expected output of T16402 but the new result is no less correct as it eliminates the narrowing (instead of the `and` as was previously done). Bumps the array, bytestring, text, and binary submodules. Co-Authored-By: Ben Gamari <ben@well-typed.com> Metric Increase: T13701 T14697
* Version bump: base-4.16 (#18712)Vladislav Zavialov2020-10-272-2/+2
| | | | Also bumps upper bounds on base in boot libraries (incl. submodules).
* Unification of Nat and NaturalsHaskellMouse2020-10-132-1/+2
| | | | | | | | | | | | | | | | | | | | | | | This commit removes the separate kind 'Nat' and enables promotion of type 'Natural' for using as type literal. It partially solves #10776 Now the following code will be successfully typechecked: data C = MkC Natural type CC = MkC 1 Before this change we had to create the separate type for promotion data C = MkC Natural data CP = MkCP Nat type CC = MkCP 1 But CP is uninhabited in terms. For backward compatibility type synonym `Nat` has been made: type Nat = Natural The user's documentation and tests have been updated. The haddock submodule also have been updated.
* Fix desugaring of record updates on data familiesSimon Peyton Jones2020-10-092-0/+34
| | | | | | | | | | | | This fixes a long-standing bug in the desugaring of record updates for data families, when the latter involves a GADT. It's all explained in Note [Update for GADTs] in GHC.HsToCore.Expr. Building the correct cast is surprisingly tricky, as that Note explains. Fixes #18809. The test case (in indexed-types/should_compile/T18809) contains several examples that exercise the dark corners.
* Improve kind generalisation, error messagesSimon Peyton Jones2020-09-244-10/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch does two things: * It refactors GHC.Tc.Errors a bit. In debugging Quick Look I was forced to look in detail at error messages, and ended up doing a bit of refactoring, esp in mkTyVarEqErr'. It's still quite a mess, but a bit better, I think. * It makes a significant improvement to the kind checking of type and class declarations. Specifically, we now ensure that if kind checking fails with an unsolved constraint, all the skolems are in scope. That wasn't the case before, which led to some obscure error messages; and occasional failures with "no skolem info" (eg #16245). Both of these, and the main Quick Look patch itself, affect a /lot/ of error messages, as you can see from the number of files changed. I've checked them all; I think they are as good or better than before. Smaller things * I documented the various instances of VarBndr better. See Note [The VarBndr tyep and its uses] in GHC.Types.Var * Renamed GHC.Tc.Solver.simpl_top to simplifyTopWanteds * A bit of refactoring in bindExplicitTKTele, to avoid the footwork with Either. Simpler now. * Move promoteTyVar from GHC.Tc.Solver to GHC.Tc.Utils.TcMType Fixes #16245 (comment 211369), memorialised as typecheck/polykinds/T16245a Also fixes the three bugs in #18640
* Postpone associated tyfam default checks until after typecheckingRyan Scott2020-09-0911-8/+33
| | | | | | | | | | | | Previously, associated type family defaults were validity-checked during typechecking. Unfortunately, the error messages that these checks produce run the risk of printing knot-tied type constructors, which will cause GHC to diverge. In order to preserve the current error message's descriptiveness, this patch postpones these validity checks until after typechecking, which are now located in the new function `GHC.Tc.Validity.checkValidAssocTyFamDeflt`. Fixes #18648.
* Don't mark closed type family equations as occurrencesRyan Scott2020-07-301-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | Previously, `rnFamInstEqn` would mark the name of the type/data family used in an equation as an occurrence, regardless of what sort of family it is. Most of the time, this is the correct thing to do. The exception is closed type families, whose equations constitute its definition and therefore should not be marked as occurrences. Overzealously counting the equations of a closed type family as occurrences can cause certain warnings to not be emitted, as observed in #18470. See `Note [Type family equations and occurrences]` in `GHC.Rename.Module` for the full story. This fixes #18470 with a little bit of extra-casing in `rnFamInstEqn`. To accomplish this, I added an extra `ClosedTyFamInfo` field to the `NonAssocTyFamEqn` constructor of `AssocTyFamInfo` and refactored the relevant call sites accordingly so that this information is propagated to `rnFamInstEqn`. While I was in town, I moved `wrongTyFamName`, which checks that the name of a closed type family matches the name in an equation for that family, from the renamer to the typechecker to avoid the need for an `ASSERT`. As an added bonus, this lets us simplify the details of `ClosedTyFamInfo` a bit.