1. 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
  2. 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
  3. 14 Nov, 2017 1 commit
  4. 11 Nov, 2017 1 commit
  5. 08 Nov, 2017 1 commit
  6. 07 Nov, 2017 2 commits
  7. 27 Oct, 2017 1 commit
  8. 05 Oct, 2017 1 commit
  9. 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
  10. 29 Aug, 2017 1 commit
  11. 22 Aug, 2017 1 commit
    • Ryan Scott's avatar
      Revise function arity mismatch errors involving TypeApplications · 84760976
      Ryan Scott authored
      Summary:
      Currently, whenever you apply a function to too many arguments and
      some of those arguments happen to be visible type applications, the error
      message that GHC gives is rather confusing. Consider the message you receive
      when typechecking `id @Int 1 2`:
      
      ```
      The function `id` is applied to three arguments,
      but its type `Int -> Int` has only one
      ```
      
      This is baffling, since the two lines treat the visible type argument `@Int`
      differently. The top line ("applied to three arguments") includes `@Int`,
      whereas the bottom line ("has only one") excludes `@Int` from consideration.
      
      There are multiple ways one could fix this, which I explain in an addendum to
      `Note [Herald for matchExpectedFunTys]`. The approach adopted here is to change
      the herald of this error message to include visible type arguments, and to
      avoid counting them in the "applied to n arguments" part of the error. The end
      result is that the new error message for `id @Int 1 2` is now:
      
      ```
      The expression `id @Int` is applied to two arguments,
      but its type `Int -> Int` has only one
      ```
      
      Test Plan: make test TEST=T13902
      
      Reviewers: goldfire, austin, bgamari
      
      Reviewed By: goldfire
      
      Subscribers: rwbarton, thomie
      
      GHC Trac Issues: #13902
      
      Differential Revision: https://phabricator.haskell.org/D3868
      84760976
  12. 31 Jul, 2017 4 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
      Reject top-level banged bindings · af89d687
      Simon Peyton Jones authored
      Bizarrely, we were not rejecting
        !x = e
      
      Fix:
      
      * In the test in DsBinds.dsTopLHsBinds, use isBangedHsBind, not
        isBangedPatBind.  (Indeed the latter dies altogther.)
      
      * Implement isBangedHsBind in HsUtils;
        be sure to handle AbsBinds
      
      All this was shown up by Trac #13594
      af89d687
    • 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
    • Simon Peyton Jones's avatar
      Refactoring around FunRhs · 2535a671
      Simon Peyton Jones authored
      * Clarify the comments around the mc_strictness field of FunRhs
      * Use record field names consistently for FunRhs
      2535a671
  13. 27 Jun, 2017 1 commit
  14. 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
  15. 12 May, 2017 1 commit
    • Ben Gamari's avatar
      Revert "Treat banged bindings as FunBinds" · 3032ae81
      Ben Gamari authored
      This partially reverts commit 37299536 as it
      doesn't actually fix #13594. Namely it does not revert the mkPrefixFunRhs
      refactoring since this is rather independent from the functional changes.
      
      Going to try again with a whole working patch
      3032ae81
  16. 11 May, 2017 1 commit
  17. 09 May, 2017 1 commit
    • Ben Gamari's avatar
      Treat banged bindings as FunBinds · 37299536
      Ben Gamari authored
      This reworks the HsSyn representation to make banged variable patterns
      (e.g. !x = e) be represented as FunBinds instead of PatBinds, adding a flag to
      FunRhs to record the bang.
      
      Fixes #13594.
      
      Reviewers: austin, goldfire, alanz, simonpj
      
      Reviewed By: simonpj
      
      Subscribers: simonpj, rwbarton, thomie, mpickering
      
      Differential Revision: https://phabricator.haskell.org/D3525
      37299536
  18. 08 May, 2017 1 commit
  19. 03 May, 2017 1 commit
  20. 27 Feb, 2017 1 commit
  21. 10 Feb, 2017 1 commit
  22. 19 Jan, 2017 1 commit
    • Richard Eisenberg's avatar
      Update levity polymorphism · e7985ed2
      Richard Eisenberg authored
      This commit implements the proposal in
      https://github.com/ghc-proposals/ghc-proposals/pull/29 and
      https://github.com/ghc-proposals/ghc-proposals/pull/35.
      
      Here are some of the pieces of that proposal:
      
      * Some of RuntimeRep's constructors have been shortened.
      
      * TupleRep and SumRep are now parameterized over a list of RuntimeReps.
      * This
      means that two types with the same kind surely have the same
      representation.
      Previously, all unboxed tuples had the same kind, and thus the fact
      above was
      false.
      
      * RepType.typePrimRep and friends now return a *list* of PrimReps. These
      functions can now work successfully on unboxed tuples. This change is
      necessary because we allow abstraction over unboxed tuple types and so
      cannot
      always handle unboxed tuples specially as we did before.
      
      * We sometimes have to create an Id from a PrimRep. I thus split PtrRep
      * into
      LiftedRep and UnliftedRep, so that the created Ids have the right
      strictness.
      
      * The RepType.RepType type was removed, as it didn't seem to help with
      * much.
      
      * The RepType.repType function is also removed, in favor of typePrimRep.
      
      * I have waffled a good deal on whether or not to keep VoidRep in
      TyCon.PrimRep. In the end, I decided to keep it there. PrimRep is *not*
      represented in RuntimeRep, and typePrimRep will never return a list
      including
      VoidRep. But it's handy to have in, e.g., ByteCodeGen and friends. I can
      imagine another design choice where we have a PrimRepV type that is
      PrimRep
      with an extra constructor. That seemed to be a heavier design, though,
      and I'm
      not sure what the benefit would be.
      
      * The last, unused vestiges of # (unliftedTypeKind) have been removed.
      
      * There were several pretty-printing bugs that this change exposed;
      * these are fixed.
      
      * We previously checked for levity polymorphism in the types of binders.
      * But we
      also must exclude levity polymorphism in function arguments. This is
      hard to check
      for, requiring a good deal of care in the desugarer. See Note [Levity
      polymorphism
      checking] in DsMonad.
      
      * In order to efficiently check for levity polymorphism in functions, it
      * was necessary
      to add a new bit of IdInfo. See Note [Levity info] in IdInfo.
      
      * It is now safe for unlifted types to be unsaturated in Core. Core Lint
      * is updated
      accordingly.
      
      * We can only know strictness after zonking, so several checks around
      * strictness
      in the type-checker (checkStrictBinds, the check for unlifted variables
      under a ~
      pattern) have been moved to the desugarer.
      
      * Along the way, I improved the treatment of unlifted vs. banged
      * bindings. See
      Note [Strict binds checks] in DsBinds and #13075.
      
      * Now that we print type-checked source, we must be careful to print
      * ConLikes correctly.
      This is facilitated by a new HsConLikeOut constructor to HsExpr.
      Particularly troublesome
      are unlifted pattern synonyms that get an extra void# argument.
      
      * Includes a submodule update for haddock, getting rid of #.
      
      * New testcases:
        typecheck/should_fail/StrictBinds
        typecheck/should_fail/T12973
        typecheck/should_run/StrictPats
        typecheck/should_run/T12809
        typecheck/should_fail/T13105
        patsyn/should_fail/UnliftedPSBind
        typecheck/should_fail/LevPolyBounded
        typecheck/should_compile/T12987
        typecheck/should_compile/T11736
      
      * Fixed tickets:
        #12809
        #12973
        #11736
        #13075
        #12987
      
      * This also adds a test case for #13105. This test case is
      * "compile_fail" and
      succeeds, because I want the testsuite to monitor the error message.
      When #13105 is fixed, the test case will compile cleanly.
      e7985ed2
  23. 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
  24. 05 Dec, 2016 1 commit
    • Simon Peyton Jones's avatar
      Fix used-variable calculation (Trac #12548) · 6305674f
      Simon Peyton Jones authored
      The used-variable calculation for pattern synonyms is a little
      tricky, for reasons described in RnBinds
      Note [Pattern synonym builders don't yield dependencies]
      
      It was right semantically, but the "unused-variable warning" was
      wrong, which led to Trac #12548.
      6305674f
  25. 17 Oct, 2016 1 commit
  26. 06 Oct, 2016 1 commit
  27. 30 Sep, 2016 1 commit
    • Simon Peyton Jones's avatar
      Fix impredicativity (again) · b612da66
      Simon Peyton Jones authored
      This patch fixes Trac #12616.
      
      Dignosis.  In TcUnify.tc_sub_type_ds we were going to some trouble to
      support co- and contra-variance even for impredicative types.  With
      -XImpredicativeTYpes, this allowed a unification variable to be
      unified with a polytype (probably wrongly) and that caused later
      trouble in the constraint solver, where -XImpredicativeTypes was /not/
      on.  In effect, -XImpredicativeTypes can't be switched on locally.
      
      Why did we want ImpredicativeTypes locally?  Because the program
      generated by GND for a higher-rank method involved impredicative
      instantation of 'coerce':
            op = coerce op   -- where op has a higher rank type
      See Note [Newtype-deriving instances] in TcGenDeriv.
      
      Cure.
      
      1.  It is ghastly to rely on ImpredicativeTypes (a 100% flaky
          feature) to instantiate coerce polymorphically.  Happily we
          now have Visible Type Application, so I've used that instead
          which should be solid and reliable.
      
      2.  I deleted the code in tc_sub_type_ds that allows the constraint
          solver to "look through" a unification variable to find a
          polytype.  That used to be essential in the days of ReturnTv,
          but it's utterly unreliable and should be consigned to the dustbin
          of history.  (We have ExpType now for the essential uses.)
      
      Tests involving ImpredicativeTypes are affected, but I'm not worried
      about them... it's advertised as a feature you can't rely on, and
      I want to reform it outright.
      b612da66
  28. 11 Sep, 2016 2 commits
  29. 26 Aug, 2016 1 commit
    • Simon Peyton Jones's avatar
      Fix scoping of type variables in instances · 0050aff2
      Simon Peyton Jones authored
      This fixes Trac #12531:
      
         class Foo x where
           foo :: forall a . x a -> x a
           default foo :: forall b . x b -> x b
           foo x = go
             where go :: x b
                   go = undefined
      
      We want 'b' to scope over the code for 'foo', but we were
      using 'a' instead.
      0050aff2
  30. 21 Jul, 2016 1 commit
    • Ömer Sinan Ağacan's avatar
      Implement unboxed sum primitive type · 714bebff
      Ömer Sinan Ağacan authored
      Summary:
      This patch implements primitive unboxed sum types, as described in
      https://ghc.haskell.org/trac/ghc/wiki/UnpackedSumTypes.
      
      Main changes are:
      
      - Add new syntax for unboxed sums types, terms and patterns. Hidden
        behind `-XUnboxedSums`.
      
      - Add unlifted unboxed sum type constructors and data constructors,
        extend type and pattern checkers and desugarer.
      
      - Add new RuntimeRep for unboxed sums.
      
      - Extend unarise pass to translate unboxed sums to unboxed tuples right
        before code generation.
      
      - Add `StgRubbishArg` to `StgArg`, and a new type `CmmArg` for better
        code generation when sum values are involved.
      
      - Add user manual section for unboxed sums.
      
      Some other changes:
      
      - Generalize `UbxTupleRep` to `MultiRep` and `UbxTupAlt` to
        `MultiValAlt` to be able to use those with both sums and tuples.
      
      - Don't use `tyConPrimRep` in `isVoidTy`: `tyConPrimRep` is really
        wrong, given an `Any` `TyCon`, there's no way to tell what its kind
        is, but `kindPrimRep` and in turn `tyConPrimRep` returns `PtrRep`.
      
      - Fix some bugs on the way: #12375.
      
      Not included in this patch:
      
      - Update Haddock for new the new unboxed sum syntax.
      
      - `TemplateHaskell` support is left as future work.
      
      For reviewers:
      
      - Front-end code is mostly trivial and adapted from unboxed tuple code
        for type checking, pattern checking, renaming, desugaring etc.
      
      - Main translation routines are in `RepType` and `UnariseStg`.
        Documentation in `UnariseStg` should be enough for understanding
        what's going on.
      
      Credits:
      
      - Johan Tibell wrote the initial front-end and interface file
        extensions.
      
      - Simon Peyton Jones reviewed this patch many times, wrote some code,
        and helped with debugging.
      
      Reviewers: bgamari, alanz, goldfire, RyanGlScott, simonpj, austin,
                 simonmar, hvr, erikd
      
      Reviewed By: simonpj
      
      Subscribers: Iceland_jack, ggreif, ezyang, RyanGlScott, goldfire,
                   thomie, mpickering
      
      Differential Revision: https://phabricator.haskell.org/D2259
      714bebff
  31. 15 Jun, 2016 1 commit
    • Simon Peyton Jones's avatar
      Re-add FunTy (big patch) · 77bb0927
      Simon Peyton Jones authored
      With TypeInType Richard combined ForAllTy and FunTy, but that was often
      awkward, and yielded little benefit becuase in practice the two were
      always treated separately.  This patch re-introduces FunTy.  Specfically
      
      * New type
          data TyVarBinder = TvBndr TyVar VisibilityFlag
        This /always/ has a TyVar it.  In many places that's just what
        what we want, so there are /lots/ of TyBinder -> TyVarBinder changes
      
      * TyBinder still exists:
          data TyBinder = Named TyVarBinder | Anon Type
      
      * data Type = ForAllTy TyVarBinder Type
                  | FunTy Type Type
                  |  ....
      
      There are a LOT of knock-on changes, but they are all routine.
      
      The Haddock submodule needs to be updated too
      77bb0927
  32. 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
  33. 06 Jun, 2016 1 commit
    • Alan Zimmerman's avatar
      Merge MatchFixity and HsMatchContext · a13cb279
      Alan Zimmerman authored
      Summary:
      MatchFixity was introduced to facilitate use of API Annotations.
      
      HsMatchContext does the same thing with more detail, but is chased
      through all over the place to provide context when processing a Match.
      
      Since we already have MatchFixity in the Match, it may as well provide
      the full context.
      
      updates submodule haddock
      
      Test Plan: ./validate
      
      Reviewers: austin, goldfire, bgamari
      
      Subscribers: thomie, mpickering
      
      Differential Revision: https://phabricator.haskell.org/D2271
      
      GHC Trac Issues: #12105
      
      (cherry picked from commit 306ecad5)
      a13cb279
  34. 21 May, 2016 1 commit
    • Andrew Farmer's avatar
      Fix deriving Ord when RebindableSyntax is enabled · 527ed724
      Andrew Farmer authored
      Deriving clauses (Ord especially) generated if-expressions with nlHsIf
      which were subject to RebindableSyntax. This changes nlHsIf to generate
      concrete if-expressions.
      
      There was also an error about calling tagToEnum# at a polymorphic type,
      which is not allowed. Fixing nlHsIf didn't fix this for some reason, so
      I generated a type ascription around the call to tagToEnum#. Not sure
      why the typechecker could not figure this out.
      
      Test Plan: Added a test, ran validate.
      
      Reviewers: simonpj, simonmar, austin, bgamari
      
      Reviewed By: bgamari
      
      Subscribers: thomie
      
      Differential Revision: https://phabricator.haskell.org/D2247
      
      GHC Trac Issues: #12080
      527ed724
  35. 12 May, 2016 1 commit