summaryrefslogtreecommitdiff
path: root/compiler/GHC/Tc/Utils/Monad.hs
Commit message (Collapse)AuthorAgeFilesLines
* 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
|
* 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
|
* 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
|
* Encapsulate the EPS IORef in a newtypeSylvain Henry2021-04-011-3/+3
|
* 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!
* Improve handling of overloaded labels, literals, lists etcwip/T19154Simon Peyton Jones2021-02-191-26/+44
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* Refactor LoggerSylvain Henry2021-02-131-20/+26
| | | | | | | | | | | | | | | | | | | | | 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
* Introduce the DecoratedSDoc typeAlfredo Di Napoli2021-02-011-16/+24
| | | | | This commit introduces a DecoratedSDoc type which replaces the old ErrDoc, and hopefully better reflects the intent.
* Rename ErrMsg into MsgEnvelopeAlfredo Di Napoli2021-02-011-9/+9
| | | | Updates Haddock submodule
* Remove ErrDoc and MsgDocAlfredo Di Napoli2021-02-011-48/+48
| | | | | | | | | | | | | This commit boldly removes the ErrDoc and the MsgDoc from the codebase. The former was introduced with the only purpose of classifying errors according to their importance, but a similar result can be obtained just by having a simple [SDoc], and placing bullets after each of them. On top of that I have taken the perhaps controversial decision to also banish MsgDoc, as it was merely a type alias over an SDoc and as such it wasn't offering any extra type safety. Granted, it was perhaps making type signatures slightly more "focused", but at the expense of cognitive burden: if it's really just an SDoc, let's call it with its proper name.
* Parameterise Messages over eAlfredo Di Napoli2021-01-221-31/+28
| | | | | | | | | This commit paves the way to a richer and more structured representation of GHC error messages, as per GHC proposal #306. More specifically 'Messages' from 'GHC.Types.Error' now gains an extra type parameter, that we instantiate to 'ErrDoc' for now. Later, this will allow us to replace ErrDoc with something more structure (for example messages coming from the parser, the typechecker etc).
* Remove errShortString, cleanup error-related functionsAlfredo Di Napoli2021-01-091-9/+6
| | | | | | | | | | | 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
* Implement Unique supply with Addr# atomic primopSylvain Henry2021-01-051-1/+0
| | | | | | | | Before this patch the compiler depended on the RTS way (threaded or not) to use atomic incrementation or not. This is wrong because the RTS is supposed to be switchable at link time, without recompilation. Now we always use atomic incrementation of the unique counter.
* Kill floatEqualities completelySimon Peyton Jones2020-12-201-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch delivers on #17656, by entirel killing off the complex floatEqualities mechanism. Previously, floatEqualities would float an equality out of an implication, so that it could be solved at an outer level. But now we simply do unification in-place, without floating the constraint, relying on level numbers to determine untouchability. There are a number of important new Notes: * GHC.Tc.Utils.Unify Note [Unification preconditions] describes the preconditions for unification, including both skolem-escape and touchability. * GHC.Tc.Solver.Interact Note [Solve by unification] describes what we do when we do unify * GHC.Tc.Solver.Monad Note [The Unification Level Flag] describes how we control solver iteration under this new scheme * GHC.Tc.Solver.Monad Note [Tracking Given equalities] describes how we track when we have Given equalities * GHC.Tc.Types.Constraint Note [HasGivenEqs] is a new explanation of the ic_given_eqs field of an implication A big raft of subtle Notes in Solver, concerning floatEqualities, disappears. Main code changes: * GHC.Tc.Solver.floatEqualities disappears entirely * GHC.Tc.Solver.Monad: new fields in InertCans, inert_given_eq_lvl and inert_given_eq, updated by updateGivenEqs See Note [Tracking Given equalities]. * In exchange for updateGivenEqa, GHC.Tc.Solver.Monad.getHasGivenEqs is much simpler and more efficient * I found I could kill of metaTyVarUpdateOK entirely One test case T14683 showed a 5.1% decrease in compile-time allocation; and T5631 was down 2.2%. Other changes were small. Metric Decrease: T14683 T5631
* Move Unit related fields from DynFlags to HscEnvSylvain Henry2020-12-141-12/+10
| | | | | | | | | | | | | 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
* Remove flattening variablesRichard Eisenberg2020-12-011-4/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 -------------------------
* Refactor -dynamic-too handlingSylvain Henry2020-11-061-4/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | 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/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* Add the proper HLint rules and remove redundant keywords from compilerHécate2020-11-011-33/+33
|
* Split GHC.Driver.TypesSylvain Henry2020-10-291-17/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* Lint the compiler for extraneous LANGUAGE pragmasHécate2020-10-101-7/+9
|
* Cache HomeUnit in HscEnv (#17957)Sylvain Henry2020-10-091-4/+5
| | | | | Instead of recreating the HomeUnit from the DynFlags every time we need it, we store it in the HscEnv.
* Improve kind generalisation, error messagesSimon Peyton Jones2020-09-241-4/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* Extract definition of DsM into GHC.HsToCore.TypesSebastian Graf2020-09-121-15/+8
| | | | | | | | | | | | | | | | | | `DsM` was previously defined in `GHC.Tc.Types`, along with `TcM`. But `GHC.Tc.Types` is in the set of transitive dependencies of `GHC.Parser`, a set which we aim to minimise. Test case `CountParserDeps` checks for that. Having `DsM` in that set means the parser also depends on the innards of the pattern-match checker in `GHC.HsToCore.PmCheck.Types`, which is the reason we have that module in the first place. In the previous commit, we represented the `TyState` by an `InertSet`, but that pulls the constraint solver as well as 250 more modules into the set of dependencies, triggering failure of `CountParserDeps`. Clearly, we want to evolve the pattern-match checker (and the desugarer) without being concerned by this test, so this patch includes a small refactor that puts `DsM` into its own module.
* Refactor UnitId pretty-printingSylvain Henry2020-08-261-2/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When we pretty-print a UnitId for the user, we try to map it back to its origin package name, version and component to print "package-version:component" instead of some hash. The UnitId type doesn't carry these information, so we have to look into a UnitState to find them. This is why the Outputable instance of UnitId used `sdocWithDynFlags` in order to access the `unitState` field of DynFlags. This is wrong for several reasons: 1. The DynFlags are accessed when the message is printed, not when it is generated. So we could imagine that the unitState may have changed in-between. Especially if we want to allow unit unloading. 2. We want GHC to support several independent sessions at once, hence several UnitState. The current approach supposes there is a unique UnitState as a UnitId doesn't indicate which UnitState to use. See the Note [Pretty-printing UnitId] in GHC.Unit for the new approach implemented by this patch. One step closer to remove `sdocDynFlags` field from `SDocContext` (#10143). Fix #18124. Also fix some Backpack code to use SDoc instead of String.
* mkUnique refactoring (#18362)Aditya Gupta2020-08-221-0/+1
| | | | | Move uniqFromMask from Unique.Supply to Unique. Move the the functions that call mkUnique from Unique to Builtin.Uniques