summaryrefslogtreecommitdiff
path: root/compiler/parser
Commit message (Collapse)AuthorAgeFilesLines
* Use FlexibleInstances for `Outputable (* p)` instead of match-all instances ↵Sebastian Graf2019-10-281-5/+6
| | | | | | | | | | | | | | with equality constraints In #17304, Richard and Simon dicovered that using `-XFlexibleInstances` for `Outputable` instances of AST data types means users can provide orphan `Outputable` instances for passes other than `GhcPass`. Type inference doesn't currently to suffer, and Richard gave an example in #17304 that shows how rare a case would be where the slightly worse type inference would matter. So I went ahead with the refactoring, attempting to fix #17304.
* Attach API Annotations for {-# SOURCE #-} import pragmaAlan Zimmerman2019-10-281-14/+13
| | | | | | | Attach the API annotations for the start and end locations of the {-# SOURCE #-} pragma in an ImportDecl. Closes #17388
* Solve constraints from top-level groups soonerRichard Eisenberg2019-10-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | Previously, all constraints from all top-level groups (as separated by top-level splices) were lumped together and solved at the end. This could leak metavariables to TH, though, and that's bad. This patch solves each group's constraints before running the next group's splice. Naturally, we now report fewer errors in some cases. One nice benefit is that this also fixes #11680, but in a much simpler way than the original fix for that ticket. Admittedly, the error messages degrade just a bit from the fix from #11680 (previously, we informed users about variables that will be brought into scope below a top-level splice, and now we just report an out-of-scope error), but the amount of complexity required throughout GHC to get that error was just not worth it. This patch thus reverts much of f93c9517a2c6e158e4a5c5bc7a3d3f88cb4ed119. Fixes #16980 Test cases: th/T16980{,a}
* Clean up `#include`s in the compilerJohn Ericson2019-10-052-3/+3
| | | | | | | | - Remove unneeded ones - Use <..> for inter-package. Besides general clean up, helps distinguish between the RTS we link against vs the RTS we compile for.
* Improve documentation around empty tuples/listsRichard Eisenberg2019-10-031-0/+8
| | | | | | | | | | | | | | This patch also changes the way we handle empty lists, simplifying them somewhat. See Note [Empty lists]. Previously, we had to special-case empty lists in the type-checker. Now no more! Finally, this patch improves some documentation around the ir_inst field used in the type-checker. This breaks a test case, but I really think the problem is #17251, not really related to this patch. Test case: typecheck/should_compile/T13680
* Add `module {-# SOURCE #-} Foo` syntax for hs-boot in bkpJohn Ericson2019-10-031-13/+26
| | | | This is a good convenience for testing.
* Standalone kind signatures (#16794)wip/top-level-kind-signaturesVladislav Zavialov2019-09-252-0/+39
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implements GHC Proposal #54: .../ghc-proposals/blob/master/proposals/0054-kind-signatures.rst With this patch, a type constructor can now be given an explicit standalone kind signature: {-# LANGUAGE StandaloneKindSignatures #-} type Functor :: (Type -> Type) -> Constraint class Functor f where fmap :: (a -> b) -> f a -> f b This is a replacement for CUSKs (complete user-specified kind signatures), which are now scheduled for deprecation. User-facing changes ------------------- * A new extension flag has been added, -XStandaloneKindSignatures, which implies -XNoCUSKs. * There is a new syntactic construct, a standalone kind signature: type <name> :: <kind> Declarations of data types, classes, data families, type families, and type synonyms may be accompanied by a standalone kind signature. * A standalone kind signature enables polymorphic recursion in types, just like a function type signature enables polymorphic recursion in terms. This obviates the need for CUSKs. * TemplateHaskell AST has been extended with 'KiSigD' to represent standalone kind signatures. * GHCi :info command now prints the kind signature of type constructors: ghci> :info Functor type Functor :: (Type -> Type) -> Constraint ... Limitations ----------- * 'forall'-bound type variables of a standalone kind signature do not scope over the declaration body, even if the -XScopedTypeVariables is enabled. See #16635 and #16734. * Wildcards are not allowed in standalone kind signatures, as partial signatures do not allow for polymorphic recursion. * Associated types may not be given an explicit standalone kind signature. Instead, they are assumed to have a CUSK if the parent class has a standalone kind signature and regardless of the -XCUSKs flag. * Standalone kind signatures do not support multiple names at the moment: type T1, T2 :: Type -> Type -- rejected type T1 = Maybe type T2 = Either String See #16754. * Creative use of equality constraints in standalone kind signatures may lead to GHC panics: type C :: forall (a :: Type) -> a ~ Int => Constraint class C a where f :: C a => a -> Int See #16758. Implementation notes -------------------- * The heart of this patch is the 'kcDeclHeader' function, which is used to kind-check a declaration header against its standalone kind signature. It does so in two rounds: 1. check user-written binders 2. instantiate invisible binders a la 'checkExpectedKind' * 'kcTyClGroup' now partitions declarations into declarations with a standalone kind signature or a CUSK (kinded_decls) and declarations without either (kindless_decls): * 'kinded_decls' are kind-checked with 'checkInitialKinds' * 'kindless_decls' are kind-checked with 'getInitialKinds' * DerivInfo has been extended with a new field: di_scoped_tvs :: ![(Name,TyVar)] These variables must be added to the context in case the deriving clause references tcTyConScopedTyVars. See #16731.
* Fix some duplication in the parserSebastian Graf2019-09-241-20/+4
| | | | | | | | | | | | | | | | | | | | | | D3673 experienced reduce/reduce conflicts when trying to use opt_instance for associated data families. That was probably because the author tried to use it for Haskell98-syntax without also applying it to GADT-syntax, which actually leads to a reduce/reduce conflict. Consider the following state: ``` data . T = T data . T where T :: T ``` The parser must decide at this point whether or not to reduce an empty `opt_instance`. But doing so would also commit to either Haskell98 or GADT syntax! Good thing we also accept an optional "instance" for GADT syntax, so the `opt_instance` is there in both productions and there's no reduce/reduce conflict anymore. Also no need to inline `opt_instance`, how it used to be.
* Remove pointless partiality in `Parser.ajs`John Ericson2019-09-201-15/+16
|
* Module hierarchy: Hs (#13009)Sylvain Henry2019-09-203-14/+14
| | | | | | | Add GHC.Hs module hierarchy replacing hsSyn. Metric Increase: haddock.compiler
* Remove unused `#include`s from parser/cutils.cJohn Ericson2019-09-121-6/+0
| | | | | Looks like these have been unused since 7c665f9ce0980ee7c81a44c8f861686395637453.
* PV is not P (#16611)Vladislav Zavialov2019-07-152-42/+133
|
* Decouple AddAnn from PVladislav Zavialov2019-07-153-14/+13
|
* Use an empty data type in TTG extension constructors (#15247)Ryan Scott2019-07-092-241/+241
| | | | | | | | | | | | | | | To avoid having to `panic` any time a TTG extension constructor is consumed, this MR introduces an uninhabited 'NoExtCon' type and uses that in every extension constructor's type family instance where it is appropriate. This also introduces a 'noExtCon' function which eliminates a 'NoExtCon', much like 'Data.Void.absurd' eliminates a 'Void'. I also renamed the existing `NoExt` type to `NoExtField` to better distinguish it from `NoExtCon`. Unsurprisingly, there is a lot of code churn resulting from this. Bumps the Haddock submodule. Fixes #15247.
* Some forall-related cleanup in deriving codeRyan Scott2019-05-231-2/+2
| | | | | | | | * Tweak the parser to allow `deriving` clauses to mention explicit `forall`s or kind signatures without gratuitous parentheses. (This fixes #14332 as a consequence.) * Allow Haddock comments on `deriving` clauses with explicit `forall`s. This requires corresponding changes in Haddock.
* Use HsTyPats in associated type family defaultsRyan Scott2019-05-221-59/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Associated type family default declarations behave strangely in a couple of ways: 1. If one tries to bind the type variables with an explicit `forall`, the `forall`'d part will simply be ignored. (#16110) 2. One cannot use visible kind application syntax on the left-hand sides of associated default equations, unlike every other form of type family equation. (#16356) Both of these issues have a common solution. Instead of using `LHsQTyVars` to represent the left-hand side arguments of an associated default equation, we instead use `HsTyPats`, which is what other forms of type family equations use. In particular, here are some highlights of this patch: * `FamEqn` is no longer parameterized by a `pats` type variable, as the `feqn_pats` field is now always `HsTyPats`. * The new design for `FamEqn` in chronicled in `Note [Type family instance declarations in HsSyn]`. * `TyFamDefltEqn` now becomes the same thing as `TyFamInstEqn`. This means that many of `TyFamDefltEqn`'s code paths can now reuse the code paths for `TyFamInstEqn`, resulting in substantial simplifications to various parts of the code dealing with associated type family defaults. Fixes #16110 and #16356.
* Implement ImportQualifiedPostShayne Fletcher2019-05-083-14/+72
|
* Fix #16632 by using the correct SrcSpan in checkTyClHdrRyan Scott2019-05-081-2/+2
| | | | | | `checkTyClHdr`'s case for `HsTyVar` was grabbing the wrong `SrcSpan`, which lead to error messages pointing to the wrong location. Easily fixed.
* 'warnSpaceAfterBang' only in patterns (#16619)Vladislav Zavialov2019-05-052-24/+18
|
* Pattern/expression ambiguity resolutionVladislav Zavialov2019-05-033-478/+844
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch removes 'EWildPat', 'EAsPat', 'EViewPat', and 'ELazyPat' from 'HsExpr' by using the ambiguity resolution system introduced earlier for the command/expression ambiguity. Problem: there are places in the grammar where we do not know whether we are parsing an expression or a pattern, for example: do { Con a b <- x } -- 'Con a b' is a pattern do { Con a b } -- 'Con a b' is an expression Until we encounter binding syntax (<-) we don't know whether to parse 'Con a b' as an expression or a pattern. The old solution was to parse as HsExpr always, and rejig later: checkPattern :: LHsExpr GhcPs -> P (LPat GhcPs) This meant polluting 'HsExpr' with pattern-related constructors. In other words, limitations of the parser were affecting the AST, and all other code (the renamer, the typechecker) had to deal with these extra constructors. We fix this abstraction leak by parsing into an overloaded representation: class DisambECP b where ... newtype ECP = ECP { runECP_PV :: forall b. DisambECP b => PV (Located b) } See Note [Ambiguous syntactic categories] for details. Now the intricacies of parsing have no effect on the hsSyn AST when it comes to the expression/pattern ambiguity.
* checkPattern error hint is PV contextVladislav Zavialov2019-04-253-90/+136
| | | | | There is a hint added to error messages reported in checkPattern. Instead of passing it manually, we put it in a ReaderT environment inside PV.
* Introduce MonadP, make PV a newtypeVladislav Zavialov2019-04-253-73/+104
| | | | | | | | | | | Previously we defined type PV = P, this had the downside that if we wanted to change PV, we would have to modify P as well. Now PV is free to evolve independently from P. The common operations addError, addFatalError, getBit, addAnnsAt, were abstracted into a class called MonadP.
* Haddock: support strict GADT args with docsAlec Theriault2019-04-191-26/+2
| | | | | | | | | Rather than massaging the output of the parser to re-arrange docs and bangs, it is simpler to patch the two places in which the strictness info is needed (to accept that the `HsBangTy` may be inside an `HsDocTy`). Fixes #16585.
* Tagless final encoding of ExpCmdI in the parserVladislav Zavialov2019-04-191-122/+131
| | | | | | | | | | | Before this change, we used a roundabout encoding: 1. a GADT (ExpCmdG) 2. a class to pass it around (ExpCmdI) 3. helpers to match on it (ecHsApp, ecHsIf, ecHsCase, ...) It is more straightforward to turn these helpers into class methods, removing the need for a GADT.
* Update Wiki URLs to point to GitLabTakenobu Tani2019-03-253-5/+5
| | | | | | | | | | | | | | | | | | | | | | | This moves all URL references to Trac Wiki to their corresponding GitLab counterparts. This substitution is classified as follows: 1. Automated substitution using sed with Ben's mapping rule [1] Old: ghc.haskell.org/trac/ghc/wiki/XxxYyy... New: gitlab.haskell.org/ghc/ghc/wikis/xxx-yyy... 2. Manual substitution for URLs containing `#` index Old: ghc.haskell.org/trac/ghc/wiki/XxxYyy...#Zzz New: gitlab.haskell.org/ghc/ghc/wikis/xxx-yyy...#zzz 3. Manual substitution for strings starting with `Commentary` Old: Commentary/XxxYyy... New: commentary/xxx-yyy... See also !539 [1]: https://gitlab.haskell.org/bgamari/gitlab-migration/blob/master/wiki-mapping.json
* Update Trac ticket URLs to point to GitLabRyan Scott2019-03-153-5/+5
| | | | | This moves all URL references to Trac tickets to their corresponding GitLab counterparts.
* Lexer: turn some fatal errors into non-fatal onesAlec Theriault2019-03-011-18/+24
| | | | | | | | | | The following previously fatal lexer errors are now non-fatal: * errors about enabling `LambdaCase` * errors about enabling `NumericUnderscores` * errors about having valid characters in primitive strings See #16270
* Visible dependent quantificationRyan Scott2019-03-012-7/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This implements GHC proposal 35 (https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0035-forall-arrow.rst) by adding the ability to write kinds with visible dependent quantification (VDQ). Most of the work for supporting VDQ was actually done _before_ this patch. That is, GHC has been able to reason about kinds with VDQ for some time, but it lacked the ability to let programmers directly write these kinds in the source syntax. This patch is primarly about exposing this ability, by: * Changing `HsForAllTy` to add an additional field of type `ForallVisFlag` to distinguish between invisible `forall`s (i.e, with dots) and visible `forall`s (i.e., with arrows) * Changing `Parser.y` accordingly The rest of the patch mostly concerns adding validity checking to ensure that VDQ is never used in the type of a term (as permitting this would require full-spectrum dependent types). This is accomplished by: * Adding a `vdqAllowed` predicate to `TcValidity`. * Introducing `splitLHsSigmaTyInvis`, a variant of `splitLHsSigmaTy` that only splits invisible `forall`s. This function is used in certain places (e.g., in instance declarations) to ensure that GHC doesn't try to split visible `forall`s (e.g., if it tried splitting `instance forall a -> Show (Blah a)`, then GHC would mistakenly allow that declaration!) This also updates Template Haskell by introducing a new `ForallVisT` constructor to `Type`. Fixes #16326. Also fixes #15658 by documenting this feature in the users' guide.
* Expression/command ambiguity resolutionVladislav Zavialov2019-02-232-270/+834
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch removes 'HsArrApp' and 'HsArrForm' from 'HsExpr' by introducing a new ambiguity resolution system in the parser. Problem: there are places in the grammar where we do not know whether we are parsing an expression or a command: proc x -> do { (stuff) -< x } -- 'stuff' is an expression proc x -> do { (stuff) } -- 'stuff' is a command Until we encounter arrow syntax (-<) we don't know whether to parse 'stuff' as an expression or a command. The old solution was to parse as HsExpr always, and rejig later: checkCommand :: LHsExpr GhcPs -> P (LHsCmd GhcPs) This meant polluting 'HsExpr' with command-related constructors. In other words, limitations of the parser were affecting the AST, and all other code (the renamer, the typechecker) had to deal with these extra constructors by panicking. We fix this abstraction leak by parsing into an intermediate representation, 'ExpCmd': data ExpCmdG b where ExpG :: ExpCmdG HsExpr CmdG :: ExpCmdG HsCmd type ExpCmd = forall b. ExpCmdG b -> PV (Located (b GhcPs)) checkExp :: ExpCmd -> PV (LHsExpr GhcPs) checkCmd :: ExpCmd -> PV (LHsCmd GhcPs) checkExp f = f ExpG -- interpret as an expression checkCmd f = f CmdG -- interpret as a command See Note [Ambiguous syntactic categories] for details. Now the intricacies of parsing have no effect on the hsSyn AST when it comes to the expression/command ambiguity. Future work: apply the same principles to the expression/pattern ambiguity.
* Handle the (~) type operator in 'tyconsym'Vladislav Zavialov2019-02-212-8/+8
| | | | | By parsing '~' in 'tyconsym' instead of 'oqtycon', we get one less shift/reduce conflict.
* Dot/bang operators in export lists (Trac #16339)Vladislav Zavialov2019-02-212-5/+10
| | | | | | | | The dot type operator was handled in the 'tyvarop' parser production, and the bang type operator in 'tyapp'. However, export lists and role annotations use 'oqtycon', so these type operators could not be exported or assigned roles. The fix is to handle them in a lower level production, 'tyconsym'.
* Fix warnings and fatal parsing errorsVladislav Zavialov2019-02-173-84/+92
|
* 'forall' always a keyword, plus the dot type operatorVladislav Zavialov2019-02-153-41/+37
|
* Implement -Wredundant-record-wildcards and -Wunused-record-wildcardsMatthew Pickering2019-02-142-12/+12
| | | | | | | | | -Wredundant-record-wildcards warns when a .. pattern binds no variables. -Wunused-record-wildcards warns when none of the variables bound by a .. pattern are used. These flags are enabled by `-Wall`.
* Fix #15849 by checking whether there's a do blocknineonine2019-02-121-1/+2
|
* Fix inverted position pragma flag in parser APIAlec Theriault2019-02-101-1/+1
| | | | | | | | The behviour of `lexTokenStream` around position pragma was accidentally inverted in 469fe6133646df5568c9486de2202124cb734242. This fixes that bug. This also unbreaks #16239.
* Fix optSemi type in Parser.yVladislav Zavialov2019-02-081-2/+1
| | | | | | | | | | | | | | | | | | | | | The definition of 'optSemi' claimed it had type ([Located a],Bool) Note that its production actually returns ([Located Token],Bool): : ';' { ([$1],True) } -- $1 :: Located Token Due to an infelicity in the implementation of 'happy -c', it effectively resulted in 'unsafeCoerce :: Token -> a'. See https://github.com/simonmar/happy/pull/134 If any consumer of 'optSemi' tried to instantiate 'a' to something not representationally equal to 'Token', they would experience a segfault. In addition to that, this definition made it impossible to compile Parser.y without the -c flag (as it's reliant on this bug to cast 'Token' to 'forall a. a').
* Cleanup in parser/Ctype.hsSylvain Henry2019-02-081-138/+135
| | | | | | | | | | | | | | | * GHC now performs constant folding on bit operations like (.|.) so we use them and we remove the misleading comment * we use Word8 instead of Int and we remove the useless conversion to Int32. Hopefully future releases of GHC could transform the big case in `charType` into a value table indexing instead of a jump table. Word8 would make the table smaller. * we use INLINABLE pragma instead of INLINE on `is_ctype`: in my test, the latter *prevents* `is_ctype` to be inlined because `charType` is inlined into `is_ctype` (to call charType`s worker on the unboxed Char directly).
* Lexer: Alternate Layout Rule injects actual not virtual bracesAlan Zimmerman2019-02-081-15/+17
| | | | | | | | | | | | | | | | | | | | | | | | | When the alternate layout rule is activated via a pragma, it injects tokens for { and } to make sure that the source is parsed properly. But it injects ITocurly and ITccurly, rather than their virtual counterparts ITvocurly and ITvccurly. This causes problems for ghc-exactprint, which tries to print these. Likewise, any injected ITsemi should have a zero-width SrcSpan. Test case (the existing T13087.hs) {-# LANGUAGE AlternativeLayoutRule #-} {-# LANGUAGE LambdaCase #-} isOne :: Int -> Bool isOne = \case 1 -> True _ -> False main = return () Closes #16279
* API Annotations: parens anns discarded for `(*)` operatorAlan Zimmerman2019-02-081-2/+2
| | | | | | | | | | | | | | | The patch from https://phabricator.haskell.org/D4865 introduces go _ (HsParTy _ (dL->L l (HsStarTy _ isUni))) acc ann fix = do { warnStarBndr l ; let name = mkOccName tcClsName (if isUni then "★" else "*") ; return (cL l (Unqual name), acc, fix, ann) } which discards the parens annotations belonging to the HsParTy. Updates haddock submodule Closes #16265
* API Annotations: AnnAt disconnected for TYPEAPPAlan Zimmerman2019-02-082-29/+42
| | | | | | | | | | | | For the code type family F1 (a :: k) (f :: k -> Type) :: Type where F1 @Peano a f = T @Peano f a the API annotation for the first @ is not attached to a SourceSpan in the ParsedSource Closes #16236
* API Annotations: more explicit foralls fixupAlan Zimmerman2019-02-082-24/+25
| | | | | | | The AnnForall annotations introduced via Phab:D4894 are not always attached to the correct SourceSpan. Closes #16230
* Refactor splice_exp in Parser.yVladislav Zavialov2019-02-051-11/+13
|
* Report multiple errorsVladislav Zavialov2019-02-032-21/+28
|
* API Annotations: Parens not attached correctly for ClassDeclAlan Zimmerman2019-01-301-19/+22
| | | | | | | | | | | The parens around the kinded tyvars should be attached to the class declaration as a whole, they are attached to the tyvar instead, outside the span. An annotation must always be within or after the span it is contained in. Closes #16212
* Revert "Batch merge"Ben Gamari2019-01-301-22/+19
| | | | This reverts commit 76c8fd674435a652c75a96c85abbf26f1f221876.
* Batch mergeBen Gamari2019-01-301-19/+22
|
* Prepare source-tree for base-4.13 MFP bumpHerbert Valerio Riedel2019-01-181-1/+4
|
* 'DynFlag'-free version of 'mkParserFlags'Alec Theriault2019-01-173-330/+296
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: This is a fixed version of the reverted d2fbc33c4ff3074126ab71654af8bbf8a46e4e11 and 5aa29231ab7603537284eff5e4caff3a73dba6d2. Obtaining a `DynFlags` is difficult, making using the lexer/parser for pure parsing/lexing unreasonably difficult, even with `mkPStatePure`. This is despite the fact that we only really need * language extension flags * warning flags * a handful of boolean options The new `mkParserFlags'` function makes is easier to directly construct a `ParserFlags`. Furthermore, since `pExtsBitmap` is just a footgun, I've gone ahead and made `ParserFlags` an abstract type. Also, we now export `ExtBits` and `getBit` instead of defining/exporting a bunch of boilerplate functions that test for a particular 'ExtBits'. In the process, I also * cleaned up an unneeded special case for `ITstatic` * made `UsePosPrags` another variant of `ExtBits` * made the logic in `reservedSymsFM` match that of `reservedWordsFM` Test Plan: make test Reviewers: bgamari, alanz, tdammers Subscribers: sjakobi, tdammers, rwbarton, mpickering, carter GHC Trac Issues: #11301 Differential Revision: https://phabricator.haskell.org/D5405
* Visible kind applicationmynguyen2019-01-032-44/+98
| | | | | | | | | | | | | | | | | | | | | | | Summary: This patch implements visible kind application (GHC Proposal 15/#12045), as well as #15360 and #15362. It also refactors unnamed wildcard handling, and requires that type equations in type families in Template Haskell be written with full type on lhs. PartialTypeSignatures are on and warnings are off automatically with visible kind application, just like in term-level. There are a few remaining issues with this patch, as documented in ticket #16082. Includes a submodule update for Haddock. Test Plan: Tests T12045a/b/c/TH1/TH2, T15362, T15592a Reviewers: simonpj, goldfire, bgamari, alanz, RyanGlScott, Iceland_jack Subscribers: ningning, Iceland_jack, RyanGlScott, int-index, rwbarton, mpickering, carter GHC Trac Issues: `#12045`, `#15362`, `#15592`, `#15788`, `#15793`, `#15795`, `#15797`, `#15799`, `#15801`, `#15807`, `#15816` Differential Revision: https://phabricator.haskell.org/D5229
View Lorry Controller Status