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* User's guide: data family kind-inference changessheaf2021-10-291-3/+12
| | | | | | | | Explain that the kind of a data family instance must now be fully determined by the header of the instance, and how one might migrate code to account for this change. Fixes #20527
* Don't default type variables in type familiessheaf2021-10-261-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | 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 -------------------------
* Warn if unicode bidirectional formatting characters are found in the source ↵Zubin Duggal2021-10-261-0/+18
| | | | (#20263)
* DmdAnal: Implement Boxity Analysis (#19871)Sebastian Graf2021-10-241-0/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch fixes some abundant reboxing of `DynFlags` in `GHC.HsToCore.Match.Literal.warnAboutOverflowedLit` (which was the topic of #19407) by introducing a Boxity analysis to GHC, done as part of demand analysis. This allows to accurately capture ad-hoc unboxing decisions previously made in worker/wrapper in demand analysis now, where the boxity info can propagate through demand signatures. See the new `Note [Boxity analysis]`. The actual fix for #19407 is described in `Note [No lazy, Unboxed demand in demand signature]`, but `Note [Finalising boxity for demand signature]` is probably a better entry-point. To support the fix for #19407, I had to change (what was) `Note [Add demands for strict constructors]` a bit (now `Note [Unboxing evaluated arguments]`). In particular, we now take care of it in `finaliseBoxity` (which is only called from demand analaysis) instead of `wantToUnboxArg`. I also had to resurrect `Note [Product demands for function body]` and rename it to `Note [Unboxed demand on function bodies returning small products]` to avoid huge regressions in `join004` and `join007`, thereby fixing #4267 again. See the updated Note for details. A nice side-effect is that the worker/wrapper transformation no longer needs to look at strictness info and other bits such as `InsideInlineableFun` flags (needed for `Note [Do not unbox class dictionaries]`) at all. It simply collects boxity info from argument demands and interprets them with a severely simplified `wantToUnboxArg`. All the smartness is in `finaliseBoxity`, which could be moved to DmdAnal completely, if it wasn't for the call to `dubiousDataConInstArgTys` which would be awkward to export. I spent some time figuring out the reason for why `T16197` failed prior to my amendments to `Note [Unboxing evaluated arguments]`. After having it figured out, I minimised it a bit and added `T16197b`, which simply compares computed strictness signatures and thus should be far simpler to eyeball. The 12% ghc/alloc regression in T11545 is because of the additional `Boxity` field in `Poly` and `Prod` that results in more allocation during `lubSubDmd` and `plusSubDmd`. I made sure in the ticky profiles that the number of calls to those functions stayed the same. We can bear such an increase here, as we recently improved it by -68% (in b760c1f). T18698* regress slightly because there is more unboxing of dictionaries happening and that causes Lint (mostly) to allocate more. Fixes #19871, #19407, #4267, #16859, #18907 and #13331. Metric Increase: T11545 T18698a T18698b Metric Decrease: T12425 T16577 T18223 T18282 T4267 T9961
* Introduce Concrete# for representation polymorphism checkssheaf2021-10-172-1/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | PHASE 1: we never rewrite Concrete# evidence. This patch migrates all the representation polymorphism checks to the typechecker, using a new constraint form Concrete# :: forall k. k -> TupleRep '[] Whenever a type `ty` must be representation-polymorphic (e.g. it is the type of an argument to a function), we emit a new `Concrete# ty` Wanted constraint. If this constraint goes unsolved, we report a representation-polymorphism error to the user. The 'FRROrigin' datatype keeps track of the context of the representation-polymorphism check, for more informative error messages. This paves the way for further improvements, such as allowing type families in RuntimeReps and improving the soundness of typed Template Haskell. This is left as future work (PHASE 2). fixes #17907 #20277 #20330 #20423 #20426 updates haddock submodule ------------------------- Metric Decrease: T5642 -------------------------
* Null eventlog writerOleg Grenrus2021-10-151-0/+8
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* Reject GADT pattern matches in arrow notationsheaf2021-10-091-0/+15
| | | | | | | | | | | | Tickets #20469 and #20470 showed that the current implementation of arrows is not at all up to the task of supporting GADTs: GHC produces ill-scoped Core programs because it doesn't propagate the evidence introduced by a GADT pattern match. For the time being, we reject GADT pattern matches in arrow notation. Hopefully we are able to add proper support for GADTs in arrows in the future.
* Add defaulting plugins.Andrei Barbu2021-10-082-0/+63
| | | | | | | | | | | | | | | 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.
* Fix rst syntax mistakes in release notesJoachim Breitner2021-10-071-3/+3
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* Disable -dynamic-too if -dynamic is also passedMatthew Pickering2021-10-061-0/+2
| | | | | | | | | | | Before if you passed both options then you would generate two identical hi/dyn_hi and o/dyn_o files, both in the dynamic way. It's better to warn this is happening rather than duplicating the work and causing potential confusion. -dynamic-too should only be used with -static. Fixes #20436
* Document interaction between unsafe FFI and GCAlexander Kjeldaas2021-09-291-5/+23
| | | | | In the multi-threaded RTS this can lead to hard to debug performance issues.
* Documented yet undocumented dump flags #18641Benjamin Maurer2021-09-282-6/+38
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* Remove outdated note about pragma layouttaylorfausak2021-09-281-3/+1
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* Add `-dsuppress-core-sizes` flag (#20342)Sylvain Henry2021-09-281-0/+8
| | | | | This flag is used to remove the output of core stats per binding in Core dumps.
* Remove unused, undocumented debug/dump flag `-ddump-vt-trace`. See 20403.Benjamin Maurer2021-09-221-1/+0
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* users-guide: Improve documentation of ticky eventsBen Gamari2021-09-183-1/+13
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* Add doc for -dyno, -dynosuf, -dynhisufZiyang Liu2021-09-172-3/+26
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* Ensure .dyn_hi doesn't overwrite .hiZiyang Liu2021-09-171-1/+9
| | | | | | | | This commit fixes the following bug: when `outputHi` is set, and both `.dyn_hi` and `.hi` are needed, both would be written to `outputHi`, causing `.dyn_hi` to overwrite `.hi`. This causes subsequent `readIface` to fail - "mismatched interface file profile tag (wanted "", got "dyn")" - triggering unnecessary rebuild.
* driver: -M allow omitting the -dep-suffix (means empty) (fix #15483)Artem Pelenitsyn2021-09-171-3/+2
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* Emit warning if bang is applied to unlifted typesTito Sacchi2021-09-172-0/+20
| | | | | | | | | | | | | | | | GHC will trigger a warning similar to the following when a strictness flag is applied to an unlifted type (primitive or defined with the Unlifted* extensions) in the definition of a data constructor. Test.hs:7:13: warning: [-Wredundant-strictness-flags] • Strictness flag has no effect on unlifted type ‘Int#’ • In the definition of data constructor ‘TestCon’ In the data type declaration for ‘Test’ | 7 | data Test = TestCon !Int# | ^^^^^^^^^^^^^ Fixes #20187
* Improve error messages involving operators from Data.Type.OrdChristiaan Baaij2021-09-171-0/+4
| | | | Fixes #20009
* Documentation: use https linksKrzysztof Gogolewski2021-09-0835-85/+85
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* Minor doc fixesKrzysztof Gogolewski2021-09-087-90/+56
| | | | | | | | | | | | | - Fix markup in 9.4 release notes - Document -ddump-cs-trace - Mention that ImpredicativeTypes is really supported only since 9.2 - Remove "There are some restrictions on the use of unboxed tuples". This used to be a list, but all those restrictions were removed. - Mark -fimplicit-import-qualified as documented - Remove "The :main and :run command" - duplicated verbatim in options - Avoid calling "main" a function (cf. #7816) - Update System.getArgs: the old location was before hierarchical modules - Note that multiplicity multiplication is not supported (#20319)
* Fix code example in the documentation of subsumptionARATA Mizuki2021-09-071-1/+1
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* TcPlugins: solve and report contras simultaneouslysheaf2021-08-231-11/+13
| | | | | | | | | | | | This changes the TcPlugin datatype to allow type-checking plugins to report insoluble constraints while at the same time solve some other constraints. This allows better error messages, as the plugin can still simplify constraints, even when it wishes to report a contradiction. Pattern synonyms TcPluginContradiction and TcPluginOk are provided for backwards compatibility: existing type-checking plugins should continue to work without modification.
* Doc fix #20226: formatting issues in 9.2.1 release notesAndreas Abel2021-08-231-3/+3
| | | | RST is brittle...
* Doc fix #20259: suggest bang patterns instead of case in hints.rstAndreas Abel2021-08-231-10/+4
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* users guide: Document -hpcdir flagBen Gamari2021-08-232-1/+12
| | | | Previously this was undocumented.
* Add rewriting to typechecking pluginssheaf2021-08-131-18/+94
| | | | | | | | | | | | | | | | | | | | | | | | | | | 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.
* Add a Typeable constraint to fromStaticPtr, addressing #19729David Simmons-Duffin2021-08-101-1/+6
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* Disable -fdefer-type-errors for linear types (#20083)Krzysztof Gogolewski2021-08-041-0/+5
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* docs: rename the "Running a compiled program" section in the users guideAdam Sandberg Ericsson2021-08-021-3/+3
| | | | | This hopefully makes it easier to find the right section when scanning the table of contents.
* Add Generically (generic Semigroup, Monoid instances) and Generically1 ↵Baldur Blöndal2021-08-021-5/+26
| | | | (generic Functor, Applicative, Alternative, Eq1, Ord1 instances) to GHC.Generics.
* ghc: Introduce --run modeBen Gamari2021-08-021-0/+14
| | | | | | As described in #18011, this mode provides similar functionality to the `runhaskell` command, but doesn't require that the user know the path of yet another executable, simplifying interactions with upstream tools.
* Improve docs of bang patterns (#19068)Krzysztof Gogolewski2021-07-281-43/+62
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* Document DerivingVia unsafety (#19786)Krzysztof Gogolewski2021-07-281-2/+3
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* Docs: use :default: and :ghc-ticket:Krzysztof Gogolewski2021-07-288-56/+62
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* Re #18087 !6238 Empty line in front of :since:Andreas Abel2021-07-271-0/+3
| | | | Ack. @monoidal
* Issue #18087: :since: for warnings of ghc 6/7/8Andreas Abel2021-07-271-0/+113
| | | | | | | | | | | Added :since: fields to users_guide on warning, for warnings introduced starting GHC 6.0. The data was extracted from the HTML docs on warnings, see https://gitlab.haskell.org/ghc/ghc/-/issues/18087 and partially verified by consulting the change logs.
* Doc: warnings: since: remove minor version number for uniformityAndreas Abel2021-07-271-5/+5
| | | | | New warnings are only released in major versions, it seems. One way or the other, a .1 minor version can always be dropped.
* Doc: tabs to spacesAndreas Abel2021-07-271-2/+2
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* Generalise reallyUnsafePtrEquality# and use itsheaf2021-07-231-0/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | fixes #9192 and #17126 updates containers submodule 1. Changes the type of the primop `reallyUnsafePtrEquality#` to the most general version possible (heterogeneous as well as levity-polymorphic): > reallyUnsafePtrEquality# > :: forall {l :: Levity} {k :: Levity} > (a :: TYPE (BoxedRep l)) (b :: TYPE (BoxedRep k)) > . a -> b -> Int# 2. Adds a new internal module, `GHC.Ext.PtrEq`, which contains pointer equality operations that are now subsumed by `reallyUnsafePtrEquality#`. These functions are then re-exported by `GHC.Exts` (so that no function goes missing from the export list of `GHC.Exts`, which is user-facing). More specifically, `GHC.Ext.PtrEq` defines: - A new function: * reallyUnsafePtrEquality :: forall (a :: Type). a -> a -> Int# - Library definitions of ex-primops: * `sameMutableArray#` * `sameSmallMutableArray` * `sameMutableByteArray#` * `sameMutableArrayArray#` * `sameMutVar#` * `sameTVar#` * `sameMVar#` * `sameIOPort#` * `eqStableName#` - New functions for comparing non-mutable arrays: * `sameArray#` * `sameSmallArray#` * `sameByteArray#` * `sameArrayArray#` These were requested in #9192. Generally speaking, existing libraries that use `reallyUnsafePtrEquality#` will continue to work with the new, levity-polymorphic version. But not all! Some (`containers`, `unordered-containers`, `dependent-map`) contain the following: > unsafeCoerce# reallyUnsafePtrEquality# a b If we make `reallyUnsafePtrEquality#` levity-polymorphic, this code fails the current GHC representation-polymorphism checks. We agreed that the right solution here is to modify the library; in this case by deleting the call to `unsafeCoerce#`, since `reallyUnsafePtrEquality#` is now type-heterogeneous too.
* Unify remaining GHCi prompt exampleEmily Martins2021-07-011-1/+1
| | | | Signed-off-by: Emily Martins <emily.flakeheart@gmail.com>
* Unify primary and secondary GHCi promptEmily Martins2021-07-011-15/+15
| | | | | | | Fixes #20042 Signed-off-by: Emily Martins <emily.flakeheart@gmail.com> Signed-off-by: Hécate Moonlight <hecate@glitchbra.in>
* Use HsExpansion for overloaded list patternssheaf2021-06-291-0/+12
| | | | Fixes #14380, #19997
* Update docs for change in parsing behaviour of infix operators like in GHC 9Zubin Duggal2021-06-281-2/+8
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* Revert "Make reallyUnsafePtrEquality# levity-polymorphic"Matthew Pickering2021-06-271-7/+0
| | | | | | | | | | | | | | | | | | | | | | | This reverts commit d1f59540e8b7be96b55ab4b286539a70bc75416c. This commit breaks the build of unordered-containers ``` [3 of 9] Compiling Data.HashMap.Internal.Array ( Data/HashMap/Internal/Array.hs, dist/build/Data/HashMap/Internal/Array.o, dist/build/Data/HashMap/Internal/Array.dyn_o ) *** Parser [Data.HashMap.Internal.Array]: Parser [Data.HashMap.Internal.Array]: alloc=21043544 time=13.621 *** Renamer/typechecker [Data.HashMap.Internal.Array]: Renamer/typechecker [Data.HashMap.Internal.Array]: alloc=151218672 time=187.083 *** Desugar [Data.HashMap.Internal.Array]: ghc: panic! (the 'impossible' happened) GHC version 9.3.20210625: expectJust splitFunTy CallStack (from HasCallStack): error, called at compiler/GHC/Data/Maybe.hs:68:27 in ghc:GHC.Data.Maybe expectJust, called at compiler/GHC/Core/Type.hs:1247:14 in ghc:GHC.Core.Type ``` Revert containers submodule update
* user-guide: Improve documentation of NumDecimalsZubin Duggal2021-06-271-6/+16
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* Make reallyUnsafePtrEquality# levity-polymorphicsheaf2021-06-251-0/+7
| | | | fixes #17126, updates containers submodule
* Update quantified_constraints.rstChristian Takle2021-06-241-2/+2
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