1. 07 Apr, 2018 1 commit
  2. 25 Mar, 2018 1 commit
    • Tao He's avatar
      Fix scoped type variables in TH for several constructs · a3986d7f
      Tao He authored
      Namely class methods, default signatures and pattern synonyms.
      
      When scoped type variables occur inside class default methods,
      default signatures and pattern synonyms, avoid re-create explicit
      type variables when represent the type signatures.
      
      This patch should fix Trac#14885.
      Signed-off-by: Tao He's avatarHE, Tao <sighingnow@gmail.com>
      
      Test Plan: make test TEST="T14885a T14885b T14885c"
      
      Reviewers: goldfire, bgamari, simonpj, RyanGlScott
      
      Reviewed By: simonpj, RyanGlScott
      
      Subscribers: rwbarton, thomie, carter
      
      GHC Trac Issues: #14885
      
      Differential Revision: https://phabricator.haskell.org/D4469
      a3986d7f
  3. 23 Mar, 2018 1 commit
    • Ryan Scott's avatar
      Allow PartialTypeSignatures in standalone deriving contexts · affdea82
      Ryan Scott authored
      Summary:
      At its core, this patch is a simple tweak that allows a user
      to write:
      
      ```lang=haskell
      deriving instance _ => Eq (Foo a)
      ```
      
      Which is functionally equivalent to:
      
      ```lang=haskell
      data Foo a = ...
        deriving Eq
      ```
      
      But with the added flexibility that `StandaloneDeriving` gives you
      (namely, the ability to use it anywhere, not just in the same module
      that `Foo` was declared in). This fixes #13324, and should hopefully
      address a use case brought up in #10607.
      
      Currently, only the use of a single, extra-constraints wildcard is
      permitted in a standalone deriving declaration. Any other wildcard
      is rejected, so things like
      `deriving instance (Eq a, _) => Eq (Foo a)` are currently forbidden.
      
      There are quite a few knock-on changes brought on by this change:
      
      * The `HsSyn` type used to represent standalone-derived instances
        was previously `LHsSigType`, which isn't sufficient to hold
        wildcard types. This needed to be changed to `LHsSigWcType` as a
        result.
      
      * Previously, `DerivContext` was a simple type synonym for
        `Maybe ThetaType`, under the assumption that you'd only ever be in
        the `Nothing` case if you were in a `deriving` clause. After this
        patch, that assumption no longer holds true, as you can also be
        in this situation with standalone deriving when an
        extra-constraints wildcard is used.
      
        As a result, I changed `DerivContext` to be a proper datatype that
        reflects the new wrinkle that this patch adds, and plumbed this
        through the relevant parts of `TcDeriv` and friends.
      
      * Relatedly, the error-reporting machinery in `TcErrors` also assumed
        that if you have any unsolved constraints in a derived instance,
        then you should be able to fix it by switching over to standalone
        deriving. This was always sound advice before, but with this new
        feature, it's possible to have unsolved constraints even when
        you're standalone-deriving something!
      
        To rectify this, I tweaked some constructors of `CtOrigin` a bit
        to reflect this new subtlety.
      
      This requires updating the Haddock submodule. See my fork at
      https://github.com/RyanGlScott/haddock/commit/067d52fd4be15a1842cbb05f42d9d482de0ad3a7
      
      Test Plan: ./validate
      
      Reviewers: simonpj, goldfire, bgamari
      
      Reviewed By: simonpj
      
      Subscribers: goldfire, rwbarton, thomie, mpickering, carter
      
      GHC Trac Issues: #13324
      
      Differential Revision: https://phabricator.haskell.org/D4383
      affdea82
  4. 05 Mar, 2018 1 commit
    • Ryan Scott's avatar
      Fix #14888 by adding more special cases for ArrowT · 6ee831f2
      Ryan Scott authored
      Summary:
      There were previously some situations where `(->)` would
      not be desugared or reified as `ArrowT`, leading to various oddities
      such as those observed in #14888. We now uniformly treat `(->)` as
      `ArrowT` in Template Haskell–world by checking for any tycon that
      has the same name as `(->)`, and converting that to `ArrowT`.
      
      Test Plan: make test TEST=T14888
      
      Reviewers: goldfire, bgamari, simonpj
      
      Reviewed By: goldfire, simonpj
      
      Subscribers: simonpj, rwbarton, thomie, carter
      
      GHC Trac Issues: #14888
      
      Differential Revision: https://phabricator.haskell.org/D4466
      6ee831f2
  5. 21 Dec, 2017 1 commit
    • Simon Peyton Jones's avatar
      Simplify HsPatSynDetails · 584cbd4a
      Simon Peyton Jones authored
      This is a pure refactoring.  Use HsConDetails to implement
      HsPatSynDetails, instead of defining a whole new data type.
      Less code, fewer types, all good.
      584cbd4a
  6. 07 Dec, 2017 1 commit
    • Simon Peyton Jones's avatar
      Refactor ConDecl: Trac #14529 · fa29df02
      Simon Peyton Jones authored
      This patch refactors HsDecls.ConDecl.  Specifically
      
      * ConDeclGADT was horrible, with all the information hidden
        inside con_res_ty.  Now it's kept separate, as it should be.
      
      * ConDeclH98: use [LHsTyVarBndr] instead of LHsQTyVars for the
        existentials. There is no implicit binding here.
      
      * Add a field con_forall to both ConDeclGADT and ConDeclH98
        which says if there is an explicit user-written forall.
      
      * Field renamings in ConDecl
           con_cxt     to con_mb_cxt
           con_details to con_args
      
      There is an accompanying submodule update to Haddock.
      
      Also the following change turned out to remove a lot of clutter:
      
      * add a smart constructor for HsAppsTy, namely mkHsAppsTy,
        and use it consistently. This avoids a lot of painful pattern
        matching for the common singleton case.
      
      Two api-annotation tests (T10278, and T10399) are broken, hence marking
      them as expect_broken(14529).  Alan is going to fix them, probably by
      changing the con_forall field to
         con_forall :: Maybe SrcSpan
      instead of Bool
      fa29df02
  7. 21 Nov, 2017 1 commit
    • Ben Gamari's avatar
      Revert "trees that grow" work · 314bc314
      Ben Gamari authored
      As documented in #14490, the Data instances currently blow up
      compilation time by too much to stomach. Alan will continue working on
      this in a branch and we will perhaps merge to 8.2 before 8.2.1 to avoid
      having to perform painful cherry-picks in 8.2 minor releases.
      
      Reverts haddock submodule.
      
      This reverts commit 47ad6578.
      This reverts commit e3ec2e7a.
      This reverts commit 438dd1cb.
      This reverts commit 0ff152c9.
      314bc314
  8. 14 Nov, 2017 1 commit
  9. 11 Nov, 2017 1 commit
  10. 08 Nov, 2017 1 commit
  11. 07 Nov, 2017 2 commits
  12. 19 Sep, 2017 1 commit
    • Herbert Valerio Riedel's avatar
      compiler: introduce custom "GhcPrelude" Prelude · f63bc730
      Herbert Valerio Riedel authored
      This switches the compiler/ component to get compiled with
      -XNoImplicitPrelude and a `import GhcPrelude` is inserted in all
      modules.
      
      This is motivated by the upcoming "Prelude" re-export of
      `Semigroup((<>))` which would cause lots of name clashes in every
      modulewhich imports also `Outputable`
      
      Reviewers: austin, goldfire, bgamari, alanz, simonmar
      
      Reviewed By: bgamari
      
      Subscribers: goldfire, rwbarton, thomie, mpickering, bgamari
      
      Differential Revision: https://phabricator.haskell.org/D3989
      f63bc730
  13. 12 Sep, 2017 1 commit
  14. 29 Aug, 2017 1 commit
  15. 31 Jul, 2017 2 commits
    • Simon Peyton Jones's avatar
      Use field names for all uses of datacon Match · 4fdc5234
      Simon Peyton Jones authored
      This is refactoring only... elimiante all positional uses
      of the data constructor Match in favour of field names.
      
      No change in behaviour.
      4fdc5234
    • Simon Peyton Jones's avatar
      Improve the desugaring of -XStrict · 46368868
      Simon Peyton Jones authored
      Trac #14035 showed that -XStrict was generating some TERRIBLE
      desugarings, espcially for bindings with INLINE pragmas. Reason: with
      -XStrict, all AbsBinds (even for non-recursive functions) went via the
      general-case deguaring for AbsBinds, namely "generate a tuple and
      select from it", even though in this case there was only one variable
      in the tuple.  And that in turn interacts terribly badly with INLINE
      pragmas.
      
      This patch cleans things up:
      
      * I killed off AbsBindsSig completely, in favour of a boolean flag
        abs_sig in AbsBinds.  See Note [The abs_sig field of AbsBinds]
      
        This allowed me to delete lots of code; and instance-method
        declarations can enjoy the benefits too.  (They could have
        before, but no one had changed them to use AbsBindsSig.)
      
      * I refactored all the AbsBinds handling in DsBinds into a new
        function DsBinds.dsAbsBinds.  This allowed me to handle the
        strict case uniformly
      46368868
  16. 28 Jul, 2017 1 commit
    • Ryan Scott's avatar
      Merge types and kinds in DsMeta · b3b564fb
      Ryan Scott authored
      Summary:
      Types and kinds are now the same in GHC... well, except in the code
      that involves Template Haskell, where types and kinds are given separate
      treatment. This aims to unify that treatment in the `DsMeta` module.
      
      The gist of this patch is replacing all uses of `repLKind` with `repLTy`.
      This is isn't quite as simple as one might imagine, since `repLTy` returns a
      `Core (Q Type)` (a monadic expression), whereas `repLKind` returns a
      `Core Kind` (a pure expression). This causes many awkward impedance mismatches.
      
      One option would be to change every combinator in `Language.Haskell.TH.Lib` to
      take `KindQ` as an argument instead of `Kind`. But this would be a breaking
      change of colossal proportions.
      
      Instead, this patch takes a somewhat different approach. This migrates the
      existing `Language.Haskell.TH.Lib` module to
      `Language.Haskell.TH.Lib.Internal`, and changes all `Kind`-related combinators
      in `Language.Haskell.TH.Lib.Internal` to live in `Q`. The new
      `Language.Haskell.TH.Lib` module then re-exports most of
      `Language.Haskell.TH.Lib.Internal` with the exception of the `Kind`-related
      combinators, for which it redefines them to be their current definitions (which
      don't live in `Q`). This allows us to retain backwards compatibility with
      previous `template-haskell` releases, but more importantly, it allows GHC to
      make as many changes to the `Internal` code as it wants for its purposes
      without fear of disrupting the public API.
      
      This solves half of #11785 (the other half being `TcSplice`).
      
      Test Plan: ./validate
      
      Reviewers: goldfire, austin, bgamari
      
      Reviewed By: goldfire
      
      Subscribers: rwbarton, thomie
      
      GHC Trac Issues: #11785
      
      Differential Revision: https://phabricator.haskell.org/D3751
      b3b564fb
  17. 11 Jul, 2017 1 commit
  18. 12 Jun, 2017 1 commit
  19. 05 Jun, 2017 1 commit
    • Alan Zimmerman's avatar
      Udate hsSyn AST to use Trees that Grow · 8e6ec0fa
      Alan Zimmerman authored
      Summary:
      See https://ghc.haskell.org/trac/ghc/wiki/ImplementingTreesThatGrow
      
      This commit prepares the ground for a full extensible AST, by replacing the type
      parameter for the hsSyn data types with a set of indices into type families,
      
          data GhcPs -- ^ Index for GHC parser output
          data GhcRn -- ^ Index for GHC renamer output
          data GhcTc -- ^ Index for GHC typechecker output
      
      These are now used instead of `RdrName`, `Name` and `Id`/`TcId`/`Var`
      
      Where the original name type is required in a polymorphic context, this is
      accessible via the IdP type family, defined as
      
          type family IdP p
          type instance IdP GhcPs = RdrName
          type instance IdP GhcRn = Name
          type instance IdP GhcTc = Id
      
      These types are declared in the new 'hsSyn/HsExtension.hs' module.
      
      To gain a better understanding of the extension mechanism, it has been applied
      to `HsLit` only, also replacing the `SourceText` fields in them with extension
      types.
      
      To preserve extension generality, a type class is introduced to capture the
      `SourceText` interface, which must be honoured by all of the extension points
      which originally had a `SourceText`.  The class is defined as
      
          class HasSourceText a where
            -- Provide setters to mimic existing constructors
            noSourceText  :: a
            sourceText    :: String -> a
      
            setSourceText :: SourceText -> a
            getSourceText :: a -> SourceText
      
      And the constraint is captured in `SourceTextX`, which is a constraint type
      listing all the extension points that make use of the class.
      
      Updating Haddock submodule to match.
      
      Test Plan: ./validate
      
      Reviewers: simonpj, shayan-najd, goldfire, austin, bgamari
      
      Subscribers: rwbarton, thomie, mpickering
      
      Differential Revision: https://phabricator.haskell.org/D3609
      8e6ec0fa
  20. 08 May, 2017 1 commit
  21. 14 Feb, 2017 1 commit
    • Adam Gundry's avatar
      Implement HasField constraint solving and modify OverloadedLabels · da493897
      Adam Gundry authored
      This implements automatic constraint solving for the new HasField class
      and modifies the existing OverloadedLabels extension, as described in
      the GHC proposal
      (https://github.com/ghc-proposals/ghc-proposals/pull/6). Per the current
      form of the proposal, it does *not* currently introduce a separate
      `OverloadedRecordFields` extension.
      
      This replaces D1687.
      
      The users guide documentation still needs to be written, but I'll do
      that after the implementation is merged, in case there are further
      design changes.
      
      Test Plan: new and modified tests in overloadedrecflds
      
      Reviewers: simonpj, goldfire, dfeuer, bgamari, austin, hvr
      
      Reviewed By: bgamari
      
      Subscribers: maninalift, dfeuer, ysangkok, thomie, mpickering
      
      Differential Revision: https://phabricator.haskell.org/D2708
      da493897
  22. 08 Feb, 2017 1 commit
  23. 26 Jan, 2017 2 commits
    • Matthew Pickering's avatar
      Template Haskell support for COMPLETE pragmas · 95dc6dc0
      Matthew Pickering authored
      Reviewers: RyanGlScott, austin, goldfire, bgamari
      
      Subscribers: thomie
      
      Differential Revision: https://phabricator.haskell.org/D2997
      
      GHC Trac Issues: #13098
      95dc6dc0
    • Matthew Pickering's avatar
      COMPLETE pragmas for enhanced pattern exhaustiveness checking · 1a3f1eeb
      Matthew Pickering authored
      This patch adds a new pragma so that users can specify `COMPLETE` sets of
      `ConLike`s in order to sate the pattern match checker.
      
      A function which matches on all the patterns in a complete grouping
      will not cause the exhaustiveness checker to emit warnings.
      
      ```
      pattern P :: ()
      pattern P = ()
      
      {-# COMPLETE P #-}
      
      foo P = ()
      ```
      
      This example would previously have caused the checker to warn that
      all cases were not matched even though matching on `P` is sufficient to
      make `foo` covering. With the addition of the pragma, the compiler
      will recognise that matching on `P` alone is enough and not emit
      any warnings.
      
      Reviewers: goldfire, gkaracha, alanz, austin, bgamari
      
      Reviewed By: alanz
      
      Subscribers: lelf, nomeata, gkaracha, thomie
      
      Differential Revision: https://phabricator.haskell.org/D2669
      
      GHC Trac Issues: #8779
      1a3f1eeb
  24. 25 Jan, 2017 1 commit
  25. 23 Jan, 2017 1 commit
    • Ryan Scott's avatar
      Don't quantify implicit type variables when quoting type signatures in TH · 729a5e45
      Ryan Scott authored
      Summary:
      A bug was introduced in GHC 8.0 in which Template Haskell-quoted type
      signatures would quantify _all_ their type variables, even the implicit ones.
      This would cause splices like this:
      
      ```
      $([d| idProxy :: forall proxy (a :: k). proxy a -> proxy a
            idProxy x = x
         |])
      ```
      
      To splice back in something that was slightly different:
      
      ```
      idProxy :: forall k proxy (a :: k). proxy a -> proxy a
      idProxy x = x
      ```
      
      Notice that the kind variable `k` is now explicitly quantified! What's worse,
      this now requires the `TypeInType` extension to be enabled.
      
      This changes the behavior of Template Haskell quoting to never explicitly
      quantify type variables which are implicitly quantified in the source.
      
      There are some other places where this behavior pops up too, including
      class methods, type ascriptions, `SPECIALIZE` pragmas, foreign imports,
      and pattern synonynms (#13018), so I fixed those too.
      
      Fixes #13018 and #13123.
      
      Test Plan: ./validate
      
      Reviewers: simonpj, goldfire, austin, bgamari
      
      Reviewed By: simonpj, goldfire
      
      Subscribers: simonpj, mpickering, thomie
      
      Differential Revision: https://phabricator.haskell.org/D2974
      
      GHC Trac Issues: #13018, #13123
      729a5e45
  26. 22 Dec, 2016 1 commit
  27. 09 Dec, 2016 1 commit
    • Ryan Scott's avatar
      Rename TH constructors for deriving strategies · 5349d648
      Ryan Scott authored
      After talking to Richard, he and I concluded that choosing the rather
      common name `Newtype` to represent the corresponding deriving strategy
      in Template Haskell was a poor choice of name. I've opted to rename it
      to something less common (`NewtypeStrategy`) while we still have time. I
      also renamed the corrsponding datatype in the GHC internals so as to
      match it.
      
      Reviewers: austin, goldfire, hvr, bgamari
      
      Reviewed By: bgamari
      
      Subscribers: thomie, mpickering
      
      Differential Revision: https://phabricator.haskell.org/D2814
      
      GHC Trac Issues: #10598
      5349d648
  28. 07 Dec, 2016 1 commit
    • Alan Zimmerman's avatar
      Add HsSyn prettyprinter tests · 499e4382
      Alan Zimmerman authored
      Summary:
      Add prettyprinter tests, which take a file, parse it, pretty print it,
      re-parse the pretty printed version and then compare the original and
      new ASTs (ignoring locations)
      
      Updates haddock submodule to match the AST changes.
      
      There are three issues outstanding
      
      1. Extra parens around a context are not reproduced. This will require an
         AST change and will be done in a separate patch.
      
      2. Currently if an `HsTickPragma` is found, this is not pretty-printed,
         to prevent noise in the output.
      
         I am not sure what the desired behaviour in this case is, so have left
         it as before. Test Ppr047 is marked as expected fail for this.
      
      3. Apart from in a context, the ParsedSource AST keeps all the parens from
         the original source.  Something is happening in the renamer to remove the
         parens around visible type application, causing T12530 to fail, as the
         dumped splice decl is after the renamer.
      
         This needs to be fixed by keeping the parens, but I do not know where they
         are being removed.  I have amended the test to pass, by removing the parens
         in the expected output.
      
      Test Plan: ./validate
      
      Reviewers: goldfire, mpickering, simonpj, bgamari, austin
      
      Reviewed By: simonpj, bgamari
      
      Subscribers: simonpj, goldfire, thomie, mpickering
      
      Differential Revision: https://phabricator.haskell.org/D2752
      
      GHC Trac Issues: #3384
      499e4382
  29. 29 Nov, 2016 1 commit
  30. 05 Nov, 2016 1 commit
  31. 01 Oct, 2016 1 commit
    • Ryan Scott's avatar
      Implement deriving strategies · 9e862765
      Ryan Scott authored
      Allows users to explicitly request which approach to `deriving` to use
      via keywords, e.g.,
      
      ```
      newtype Foo = Foo Bar
        deriving Eq
        deriving stock    Ord
        deriving newtype Show
      ```
      
      Fixes #10598. Updates haddock submodule.
      
      Test Plan: ./validate
      
      Reviewers: hvr, kosmikus, goldfire, alanz, bgamari, simonpj, austin,
      erikd, simonmar
      
      Reviewed By: alanz, bgamari, simonpj
      
      Subscribers: thomie, mpickering, oerjan
      
      Differential Revision: https://phabricator.haskell.org/D2280
      
      GHC Trac Issues: #10598
      9e862765
  32. 29 Aug, 2016 1 commit
  33. 23 Aug, 2016 1 commit
    • Ryan Scott's avatar
      Template Haskell support for unboxed sums · 613d7455
      Ryan Scott authored
      This adds new constructors `UnboxedSumE`, `UnboxedSumT`, and
      `UnboxedSumP` to represent unboxed sums in Template Haskell.
      
      One thing you can't currently do is, e.g., `reify ''(#||#)`, since I
      don't believe unboxed sum type/data constructors can be written in
      prefix form.  I will look at fixing that as part of #12514.
      
      Fixes #12478.
      
      Test Plan: make test TEST=T12478_{1,2,3}
      
      Reviewers: osa1, goldfire, austin, bgamari
      
      Reviewed By: goldfire, bgamari
      
      Subscribers: thomie
      
      Differential Revision: https://phabricator.haskell.org/D2448
      
      GHC Trac Issues: #12478
      613d7455
  34. 20 Jul, 2016 1 commit
    • Ömer Sinan Ağacan's avatar
      Support SCC pragmas in declaration context · 98b2c508
      Ömer Sinan Ağacan authored
      Not having SCCs at the top level is becoming annoying real quick. For
      simplest cases, it's possible to do this transformation:
      
          f x y = ...
          =>
          f = {-# SCC f #-} \x y -> ...
      
      However, it doesn't work when there's a `where` clause:
      
          f x y = <t is in scope>
            where t = ...
          =>
          f = {-# SCC f #-} \x y -> <t is out of scope>
            where t = ...
      
      Or when we have a "equation style" definition:
      
          f (C1 ...) = ...
          f (C2 ...) = ...
          f (C3 ...) = ...
          ...
      
      (usual solution is to rename `f` to `f'` and define a new `f` with a
      `SCC`)
      
      This patch implements support for SCC annotations in declaration
      contexts. This is now a valid program:
      
          f x y = ...
            where
              g z = ...
              {-# SCC g #-}
          {-# SCC f #-}
      
      Test Plan: This passes slow validate (no new failures added).
      
      Reviewers: goldfire, mpickering, austin, bgamari, simonmar
      
      Reviewed By: bgamari, simonmar
      
      Subscribers: simonmar, thomie, mpickering
      
      Differential Revision: https://phabricator.haskell.org/D2407
      98b2c508
  35. 06 Jul, 2016 1 commit
    • Facundo Domínguez's avatar
      Have addModFinalizer expose the local type environment. · 567dbd9b
      Facundo Domínguez authored
      Summary:
      This annotates the splice point with 'HsSpliced ref e' where 'e' is the
      result of the splice. 'ref' is a reference that the typechecker will fill with
      the local type environment.
      
      The finalizer then reads the ref and uses the local type environment, which
      causes 'reify' to find local variables when run in the finalizer.
      
      Test Plan: ./validate
      
      Reviewers: simonpj, simonmar, bgamari, austin, goldfire
      
      Reviewed By: goldfire
      
      Subscribers: simonmar, thomie, mboes
      
      Differential Revision: https://phabricator.haskell.org/D2286
      
      GHC Trac Issues: #11832
      567dbd9b
  36. 01 Jul, 2016 1 commit
  37. 13 Jun, 2016 1 commit
    • Simon Peyton Jones's avatar
      Improve typechecking of let-bindings · 15b9bf4b
      Simon Peyton Jones authored
      This major commit was initially triggered by #11339, but it spiraled
      into a major review of the way in which type signatures for bindings
      are handled, especially partial type signatures.  On the way I fixed a
      number of other bugs, namely
         #12069
         #12033
         #11700
         #11339
         #11670
      
      The main change is that I completely reorganised the way in which type
      signatures in bindings are handled. The new story is in TcSigs
      Note [Overview of type signatures].  Some specific:
      
      * Changes in the data types for signatures in TcRnTypes:
        TcIdSigInfo and new TcIdSigInst
      
      * New module TcSigs deals with typechecking type signatures
        and pragmas. It contains code mostly moved from TcBinds,
        which is already too big
      
      * HsTypes: I swapped the nesting of HsWildCardBndrs
        and HsImplicitBndsrs, so that the wildcards are on the
        oustide not the insidde in a LHsSigWcType.  This is just
        a matter of convenient, nothing deep.
      
      There are a host of other changes as knock-on effects, and
      it all took FAR longer than I anticipated :-).  But it is
      a significant improvement, I think.
      
      Lots of error messages changed slightly, some just variants but
      some modest improvements.
      
      New tests
      
      * typecheck/should_compile
          * SigTyVars: a scoped-tyvar test
          * ExPat, ExPatFail: existential pattern bindings
          * T12069
          * T11700
          * T11339
      
      * partial-sigs/should_compile
          * T12033
          * T11339a
          * T11670
      
      One thing to check:
      
      * Small change to output from ghc-api/landmines.
        Need to check with Alan Zimmerman
      15b9bf4b