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* Remove duplicate modules in GHCi %s promptPhilipp Dargel2021-05-031-1/+1
| | | | fixes #19757
* Replace (ptext .. sLit) with `text`Sylvain Henry2021-04-291-6/+6
| | | | | | | | | | | | | | | 1. `text` is as efficient as `ptext . sLit` thanks to the rewrite rules 2. `text` is visually nicer than `ptext . sLit` 3. `ptext . sLit` encourages using one `ptext` for several `sLit` as in: ptext $ case xy of ... -> sLit ... ... -> sLit ... which may allocate SDoc's TextBeside constructors at runtime instead of sharing them into CAFs.
* Add GhcMessage and ancillary typesAlfredo Di Napoli2021-04-291-6/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* Only load package environment file once when starting GHCiMatthew Pickering2021-04-181-2/+6
| | | | | | | | | | | | | | | Since d880d6b2e48268f5ed4d3eb751fe24cc833e9221 the parsing of the environment files was moved to `parseDynamicFlags`, under the assumption it was typically only called once. It turns out not to be true in GHCi and this led to continually reparsing the environment file whenever a new option was set, the options were appended to the package state and hence all packages reloaded, as it looked like the options were changed. The simplest fix seems to be a clearer specification: > Package environment files are only loaded in GHCi during initialisation. Fixes #19650
* Don't produce platformConstants fileSylvain Henry2021-04-101-4/+0
| | | | It isn't used for anything anymore
* Don't tidy type in pprTypeForUserMatthew Pickering2021-04-091-7/+8
| | | | | | | | | | | | | | | | There used to be some cases were kinds were not generalised properly before being printed in GHCi. This seems to have changed in the past so now it's uncessary to tidy before printing out the test case. ``` > :set -XPolyKinds > data A x y > :k A k1 -> k2 -> A ``` This tidying was causing issues with an attempt to increase sharing by making `mkTyConApp` (see !4762)
* Move HPT in UnitEnvSylvain Henry2021-04-011-2/+2
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* Add `MessageClass`, rework `Severity` and add `DiagnosticReason`.wip/adinapoli-message-class-new-designAlfredo Di Napoli2021-03-292-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* Add UnitId to Target recordFendor2021-03-283-15/+15
| | | | | | | | | | In the future, we want `HscEnv` to support multiple home units at the same time. This means, that there will be 'Target's that do not belong to the current 'HomeUnit'. This is an API change without changing behaviour. Update haddock submodule to incorporate API changes.
* Bump Win32 to 2.13.0.0GHC GitLab CI2021-03-261-1/+1
| | | | Bumps Win32 submodule.
* Refactor FinderCacheSylvain Henry2021-03-262-4/+12
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* Refactor NameCacheSylvain Henry2021-03-261-1/+4
| | | | | | | | * Make NameCache the mutable one and replace NameCacheUpdater with it * Remove NameCache related code duplicated into haddock Bump haddock submodule
* Move loader state into InterpSylvain Henry2021-03-232-20/+20
| | | | | | | | | | | | | | | | | | The loader state was stored into HscEnv. As we need to have two interpreters and one loader state per interpreter in #14335, it's natural to make the loader state a field of the Interp type. As a side effect, many functions now only require a Interp parameter instead of HscEnv. Sadly we can't fully free GHC.Linker.Loader of HscEnv yet because the loader is initialised lazily from the HscEnv the first time it is used. This is left as future work. HscEnv may not contain an Interp value (i.e. hsc_interp :: Maybe Interp). So a side effect of the previous side effect is that callers of the modified functions now have to provide an Interp. It is satisfying as it pushes upstream the handling of the case where HscEnv doesn't contain an Interpreter. It is better than raising a panic (less partial functions, "parse, don't validate", etc.).
* GHC Exactprint main commitAlan Zimmerman2021-03-202-18/+20
| | | | | | | | Metric Increase: T10370 parsing001 Updates haddock submodule
* Ignore breakpoint for a specified number of iterations. (#19157)Roland Senn2021-03-102-38/+91
| | | | | | | | | | | | | | | | * Implement new debugger command `:ignore` to set an `ignore count` for a specified breakpoint. * Allow new optional parameter on `:continue` command to set an `ignore count` for the current breakpoint. * In the Interpreter replace the current `Word8` BreakArray with an `Int` array. * Change semantics of values in `BreakArray` to: n < 0 : Breakpoint is disabled. n == 0 : Breakpoint is enabled. n > 0 : Breakpoint is enabled, but ignore next `n` iterations. * Rewrite `:enable`/`:disable` processing as a special case of `:ignore`. * Remove references to `BreakArray` from `ghc/UI.hs`.
* Use GHC2021 as default languageJoachim Breitner2021-03-101-4/+4
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* Introduce GHC2021 languageJoachim Breitner2021-03-101-4/+4
| | | | | | This adds support for -XGHC2021, as described in Proposal 0380 [1]. [1] https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0380-ghc2021.rst
* template-haskell: Add putDoc, getDoc, withDecDoc and friendsLuke Lau2021-03-101-2/+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
* Bump bytestring submodule to 0.11.1.0Ben Gamari2021-03-101-1/+1
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* Add a flag to dump the FastString tableSylvain Henry2021-03-031-1/+8
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* Minor simplification for leak indicatorsSylvain Henry2021-03-031-15/+18
| | | | Avoid returning a lazy panic value when leak indicators are disabled.
* GHCi: Always show fixityLeif Metcalf2021-02-221-10/+20
| | | | | | | | | | | | | | | | | | | We used to only show the fixity of an operator if it wasn't the default fixity. Usually this was when the fixity was undeclared, but it could also arise if one declared the fixity of an operator as infixl 9, the default fixity. This commit makes it so that :i always shows the fixity of an operator, even if it is unset. We may want in the future to keep track of whether an operator's fixity is defined, so that we can print a comment like infixl 9 # -- Assumed, since no fixity is declared. for operators with no specified fixity, and so that we can print fixity of a term with a non-symbolic term when its fixity has been manually specified as infixl 9. Implements #19200.
* directory: ensure xdg compliance (Fix #6077)Gauvain 'GovanifY' Roussel-Tarbouriech2021-02-181-2/+16
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* Drop GHC_LOADED_IN_GHCIBen Gamari2021-02-141-13/+0
| | | | | | | This previously supported the ghc-in-ghci script which has been since dropped. Hadrian's ghci support does not need this macro (which disabled uses of UnboxedTuples) since it uses `-fno-code` rather than produce bytecode.
* GHCi :complete command for operators: Fix spaceless cases of #10576.Roland Senn2021-02-131-2/+11
| | | | | | | When separating operators from identifiers in a `:complete` command take advantage from the different character sets of the two items: * operators contain only specialSymbol characters. * Identifiers don't contain specialSymbol characters, with the exception of dots.
* Refactor LoggerSylvain Henry2021-02-133-25/+34
| | | | | | | | | | | | | | | | | | | | | Before this patch, the only way to override GHC's default logging behavior was to set `log_action`, `dump_action` and `trace_action` fields in DynFlags. This patch introduces a new Logger abstraction and stores it in HscEnv instead. This is part of #17957 (avoid storing state in DynFlags). DynFlags are duplicated and updated per-module (because of OPTIONS_GHC pragma), so we shouldn't store global state in them. This patch also fixes a race in parallel "--make" mode which updated the `generatedDumps` IORef concurrently. Bump haddock submodule The increase in MultilayerModules is tracked in #19293. Metric Increase: MultiLayerModules
* Fix typosBrian Wignall2021-02-061-1/+1
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* ghci: Take editor from VISUAL environment variableBen Gamari2021-01-301-5/+6
| | | | | | Following the example of `git`, as noted in #19030. Fixes #19030.
* Add explicit import lists to Data.List importsOleg Grenrus2021-01-292-2/+2
| | | | | | | | | | | | | Related to a future change in Data.List, https://downloads.haskell.org/ghc/8.10.3/docs/html/users_guide/using-warnings.html?highlight=wcompat#ghc-flag--Wcompat-unqualified-imports Companion pull&merge requests: - https://github.com/judah/haskeline/pull/153 - https://github.com/haskell/containers/pull/762 - https://gitlab.haskell.org/ghc/packages/hpc/-/merge_requests/9 After these the actual change in Data.List should be easy to do.
* Add additional context to :doc output (#19055)Aaron Allen2021-01-271-9/+58
| | | | | | With this change, the type/kind of an object as well as it's category and definition site are added to the output of the :doc command for each object matching the argument string.
* Remove errShortString, cleanup error-related functionsAlfredo Di Napoli2021-01-092-0/+2
| | | | | | | | | | | This commit removes the errShortString field from the ErrMsg type, allowing us to cleanup a lot of dynflag-dependent error functions, and move them in a more specialised 'GHC.Driver.Errors' closer to the driver, where they are actually used. Metric Increase: T4801 T9961
* GHCi: Fill field `DynFlags.dumpPrefix`. (Fixes #17500)Roland Senn2021-01-072-2/+18
| | | | | | | | | | | For interactive evaluations set the field `DynFlags.dumpPrefix` to the GHCi internal module name. The GHCi module name for an interactive evaluation is something like `Ghci9`. To avoid user confusion, don't dump any data for GHCi internal evaluations. Extend the comment for `DynFlags.dumpPrefix` and fix a little typo in a comment about the GHCi internal module names.
* Put hole instantiation typechecking in the module graph and fix driver batch ↵John Ericson2020-12-281-4/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | mode backpack edges Backpack instantiations need to be typechecked to make sure that the arguments fit the parameters. `tcRnInstantiateSignature` checks instantiations with concrete modules, while `tcRnCheckUnit` checks instantiations with free holes (signatures in the current modules). Before this change, it worked that `tcRnInstantiateSignature` was called after typechecking the argument module, see `HscMain.hsc_typecheck`, while `tcRnCheckUnit` was called in `unsweep'` where-bound in `GhcMake.upsweep`. `tcRnCheckUnit` was called once per each instantiation once all the argument sigs were processed. This was done with simple "to do" and "already done" accumulators in the fold. `parUpsweep` did not implement the change. With this change, `tcRnCheckUnit` instead is associated with its own node in the `ModuleGraph`. Nodes are now: ```haskell data ModuleGraphNode -- | Instantiation nodes track the instantiation of other units -- (backpack dependencies) with the holes (signatures) of the current package. = InstantiationNode InstantiatedUnit -- | There is a module summary node for each module, signature, and boot module being built. | ModuleNode ExtendedModSummary ``` instead of just `ModSummary`; the `InstantiationNode` case is the instantiation of a unit to be checked. The dependencies of such nodes are the same "free holes" as was checked with the accumulator before. Both versions of upsweep on such a node call `tcRnCheckUnit`. There previously was an `implicitRequirements` function which would crawl through every non-current-unit module dep to look for all free holes (signatures) to add as dependencies in `GHC.Driver.Make`. But this is no good: we shouldn't be looking for transitive anything when building the graph: the graph should only have immediate edges and the scheduler takes care that all transitive requirements are met. So `GHC.Driver.Make` stopped using `implicitRequirements`, and instead uses a new `implicitRequirementsShallow`, which just returns the outermost instantiation node (or module name if the immediate dependency is itself a signature). The signature dependencies are just treated like any other imported module, but the module ones then go in a list stored in the `ModuleNode` next to the `ModSummary` as the "extra backpack dependencies". When `downsweep` creates the mod summaries, it adds this information too. ------ There is one code quality, and possible correctness thing left: In addition to `implicitRequirements` there is `findExtraSigImports`, which says something like "if you are an instantiation argument (you are substituted or a signature), you need to import its things too". This is a little non-local so I am not quite sure how to get rid of it in `GHC.Driver.Make`, but we probably should eventually. First though, let's try to make a test case that observes that we don't do this, lest it actually be unneeded. Until then, I'm happy to leave it as is. ------ Beside the ability to use `-j`, the other major user-visibile side effect of this change is that that the --make progress log now includes "Instantiating" messages for these new nodes. Those also are numbered like module nodes and count towards the total. ------ Fixes #17188 Updates hackage submomdule Metric Increase: T12425 T13035
* Move Unit related fields from DynFlags to HscEnvSylvain Henry2020-12-144-57/+60
| | | | | | | | | | | | | The unit database cache, the home unit and the unit state were stored in DynFlags while they ought to be stored in the compiler session state (HscEnv). This patch fixes this. It introduces a new UnitEnv type that should be used in the future to handle separate unit environments (especially host vs target units). Related to #17957 Bump haddock submodule
* Elide extraneous messages for :doc command (#15784)Aaron Allen2020-12-111-5/+15
| | | | | | | | Do not print `<has no documentation>` alongside a valid doc. Additionally, if two matching symbols lack documentation then the message will only be printed once. Hence, `<has no documentation>` will be printed at most once and only if all matching symbols are lacking docs.
* [Sized Cmm] properly retain sizes.Moritz Angermann2020-11-261-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* Bump time submodule to 1.11.1Ben Gamari2020-11-221-1/+1
| | | | | | Also bumps directory, Cabal, hpc, time, and unix submodules. Closes #18847.
* Move Plugins into HscEnv (#17957)Sylvain Henry2020-11-212-17/+6
| | | | | | | | | | Loaded plugins have nothing to do in DynFlags so this patch moves them into HscEnv (session state). "DynFlags plugins" become "Driver plugins" to still be able to register static plugins. Bump haddock submodule
* ghc-bin: Build with eventlogging by defaultBen Gamari2020-11-151-0/+2
| | | | | | We now have all sorts of great facilities using the eventlog which were previously unavailable without building a custom GHC. Fix this by linking with `-eventlog` by default.
* Refactor -dynamic-too handlingSylvain Henry2020-11-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | 1) Don't modify DynFlags (too much) for -dynamic-too: now when we generate dynamic outputs for "-dynamic-too", we only set "dynamicNow" boolean field in DynFlags instead of modifying several other fields. These fields now have accessors that take dynamicNow into account. 2) Use DynamicTooState ADT to represent -dynamic-too state. It's much clearer than the undocumented "DynamicTooConditional" that was used before. As a result, we can finally remove the hscs_iface_dflags field in HscRecomp. There was a comment on this field saying: "FIXME (osa): I don't understand why this is necessary, but I spent almost two days trying to figure this out and I couldn't .. perhaps someone who understands this code better will remove this later." I don't fully understand the details, but it was needed because of the changes made to the DynFlags for -dynamic-too. There is still something very dubious in GHC.Iface.Recomp: we have to disable the "dynamicNow" flag at some point for some Backpack's "heinous hack" to continue to work. It may be because interfaces for indefinite units are always non-dynamic, or because we mix and match dynamic and non-dynamic interfaces (#9176), or something else, who knows?
* Replace HsImplicitBndrs with HsOuterTyVarBndrsRyan Scott2020-11-061-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This refactors the GHC AST to remove `HsImplicitBndrs` and replace it with `HsOuterTyVarBndrs`, a type which records whether the outermost quantification in a type is explicit (i.e., with an outermost, invisible `forall`) or implicit. As a result of this refactoring, it is now evident in the AST where the `forall`-or-nothing rule applies: it's all the places that use `HsOuterTyVarBndrs`. See the revamped `Note [forall-or-nothing rule]` in `GHC.Hs.Type` (previously in `GHC.Rename.HsType`). Moreover, the places where `ScopedTypeVariables` brings lexically scoped type variables into scope are a subset of the places that adhere to the `forall`-or-nothing rule, so this also makes places that interact with `ScopedTypeVariables` easier to find. See the revamped `Note [Lexically scoped type variables]` in `GHC.Hs.Type` (previously in `GHC.Tc.Gen.Sig`). `HsOuterTyVarBndrs` are used in type signatures (see `HsOuterSigTyVarBndrs`) and type family equations (see `HsOuterFamEqnTyVarBndrs`). The main difference between the former and the latter is that the former cares about specificity but the latter does not. There are a number of knock-on consequences: * There is now a dedicated `HsSigType` type, which is the combination of `HsOuterSigTyVarBndrs` and `HsType`. `LHsSigType` is now an alias for an `XRec` of `HsSigType`. * Working out the details led us to a substantial refactoring of the handling of explicit (user-written) and implicit type-variable bindings in `GHC.Tc.Gen.HsType`. Instead of a confusing family of higher order functions, we now have a local data type, `SkolemInfo`, that controls how these binders are kind-checked. It remains very fiddly, not fully satisfying. But it's better than it was. Fixes #16762. Bumps the Haddock submodule. Co-authored-by: Simon Peyton Jones <simonpj@microsoft.com> Co-authored-by: Richard Eisenberg <rae@richarde.dev> Co-authored-by: Zubin Duggal <zubin@cmi.ac.in>
* Linker: reorganize linker related codeSylvain Henry2020-11-032-5/+5
| | | | | | | Move linker related code into GHC.Linker. Previously it was scattered into GHC.Unit.State, GHC.Driver.Pipeline, GHC.Runtime.Linker, etc. Add documentation in GHC.Linker
* Split GHC.Driver.TypesSylvain Henry2020-10-294-42/+56
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I was working on making DynFlags stateless (#17957), especially by storing loaded plugins into HscEnv instead of DynFlags. It turned out to be complicated because HscEnv is in GHC.Driver.Types but LoadedPlugin isn't: it is in GHC.Driver.Plugins which depends on GHC.Driver.Types. I didn't feel like introducing yet another hs-boot file to break the loop. Additionally I remember that while we introduced the module hierarchy (#13009) we talked about splitting GHC.Driver.Types because it contained various unrelated types and functions, but we never executed. I didn't feel like making GHC.Driver.Types bigger with more unrelated Plugins related types, so finally I bit the bullet and split GHC.Driver.Types. As a consequence this patch moves a lot of things. I've tried to put them into appropriate modules but nothing is set in stone. Several other things moved to avoid loops. * Removed Binary instances from GHC.Utils.Binary for random compiler things * Moved Typeable Binary instances into GHC.Utils.Binary.Typeable: they import a lot of things that users of GHC.Utils.Binary don't want to depend on. * put everything related to Units/Modules under GHC.Unit: GHC.Unit.Finder, GHC.Unit.Module.{ModGuts,ModIface,Deps,etc.} * Created several modules under GHC.Types: GHC.Types.Fixity, SourceText, etc. * Split GHC.Utils.Error (into GHC.Types.Error) * Finally removed GHC.Driver.Types Note that this patch doesn't put loaded plugins into HscEnv. It's left for another patch. Bump haddock submodule
* API Annotations: Keep track of unicode for linear arrow notationwip/az/unicode-hsscaledAlan Zimmerman2020-10-201-2/+2
| | | | | | | | | | | The linear arrow can be parsed as `%1 ->` or a direct single token unicode equivalent. Make sure that this distinction is captured in the parsed AST by using IsUnicodeSyntax where it appears, and introduce a new API Annotation, AnnMult to represent its location when unicode is not used. Updated haddock submodule
* Implement -Woperator-whitespace (#18834)Vladislav Zavialov2020-10-191-5/+5
| | | | | | | | | | | | | | This patch implements two related warnings: -Woperator-whitespace-ext-conflict warns on uses of infix operators that would be parsed differently were a particular GHC extension enabled -Woperator-whitespace warns on prefix, suffix, and tight infix uses of infix operators Updates submodules: haddock, containers.
* Move File Target parser to library #18596Fendor2020-10-091-70/+2
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* Expose RTS-only ways (#18651)Sylvain Henry2020-10-091-2/+2
| | | | | Some RTS ways are exposed via settings (ghcThreaded, ghcDebugged) but not all. It's simpler if the RTS exposes them all itself.
* Bump Cabal, hsc2hs, directory, process submodulesBen Gamari2020-09-301-1/+1
| | | | Necessary for recent Win32 bump.
* Make the parser module less dependent on DynFlagsSylvain Henry2020-09-291-2/+3
| | | | Bump haddock submodule
* Implement Quick Look impredicativitySimon Peyton Jones2020-09-241-7/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch implements Quick Look impredicativity (#18126), sticking very closely to the design in A quick look at impredicativity, Serrano et al, ICFP 2020 The main change is that a big chunk of GHC.Tc.Gen.Expr has been extracted to two new modules GHC.Tc.Gen.App GHC.Tc.Gen.Head which deal with typechecking n-ary applications, and the head of such applications, respectively. Both contain a good deal of documentation. Three other loosely-related changes are in this patch: * I implemented (partly by accident) points (2,3)) of the accepted GHC proposal "Clean up printing of foralls", namely https://github.com/ghc-proposals/ghc-proposals/blob/ master/proposals/0179-printing-foralls.rst (see #16320). In particular, see Note [TcRnExprMode] in GHC.Tc.Module - :type instantiates /inferred/, but not /specified/, quantifiers - :type +d instantiates /all/ quantifiers - :type +v is killed off That completes the implementation of the proposal, since point (1) was done in commit df08468113ab46832b7ac0a7311b608d1b418c4d Author: Krzysztof Gogolewski <krzysztof.gogolewski@tweag.io> Date: Mon Feb 3 21:17:11 2020 +0100 Always display inferred variables using braces * HsRecFld (which the renamer introduces for record field selectors), is now preserved by the typechecker, rather than being rewritten back to HsVar. This is more uniform, and turned out to be more convenient in the new scheme of things. * The GHCi debugger uses a non-standard unification that allows the unification variables to unify with polytypes. We used to hack this by using ImpredicativeTypes, but that doesn't work anymore so I introduces RuntimeUnkTv. See Note [RuntimeUnkTv] in GHC.Runtime.Heap.Inspect Updates haddock submodule. WARNING: this patch won't validate on its own. It was too hard to fully disentangle it from the following patch, on type errors and kind generalisation. Changes to tests * Fixes #9730 (test added) * Fixes #7026 (test added) * Fixes most of #8808, except function `g2'` which uses a section (which doesn't play with QL yet -- see #18126) Test added * Fixes #1330. NB Church1.hs subsumes Church2.hs, which is now deleted * Fixes #17332 (test added) * Fixes #4295 * This patch makes typecheck/should_run/T7861 fail. But that turns out to be a pre-existing bug: #18467. So I have just made T7861 into expect_broken(18467)