1. 14 Oct, 2016 1 commit
    • Ryan Scott's avatar
      Make error when deriving an instance for a typeclass less misleading · d5a4e49d
      Ryan Scott authored
      Before, when you attempted to derive an instance for a typeclass,
      e.g.,
      
      ```
      class C1 (a :: Constraint) where
      class C2 where
      
      deriving instance C1 C2
      ```
      
      GHC would complain that `C2`'s data constructors aren't in scope. But
      that
      makes no sense, since typeclasses don't have constructors! By refining
      the
      checks that GHC performs when deriving, we can make the error message a
      little more sensible.
      
      This also cleans up a related `DeriveAnyClass` infelicity. Before, you
      wouldn't have been able to compile code like this:
      
      ```
      import System.IO (Handle)
      class C a
      deriving instance C Handle
      ```
      
      Since GHC was requiring that all data constructors of `Handle` be in
      scope. But `DeriveAnyClass` doesn't even generate code that mentions
      any data constructors, so this requirement is silly!
      
      Fixes #11509.
      
      Test Plan: make test TEST=T11509
      
      Reviewers: simonpj, austin, bgamari
      
      Reviewed By: simonpj, bgamari
      
      Subscribers: thomie, simonpj
      
      Differential Revision: https://phabricator.haskell.org/D2558
      
      GHC Trac Issues: #11509
      d5a4e49d
  2. 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
  3. 28 Sep, 2016 1 commit
  4. 24 Sep, 2016 2 commits
  5. 12 Sep, 2016 3 commits
  6. 08 Sep, 2016 1 commit
  7. 31 Aug, 2016 1 commit
  8. 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
  9. 20 Jul, 2016 1 commit
    • thomasw's avatar
      Update docs for partial type signatures (#12365) · 627c767b
      thomasw authored
      * Update the sample error messages. The messages have been reworded and
        reformatted since GHC 7.10.
      
      * Mention `TypeApplications` in "Where can they occur?"
      
      * The name of a named wild card is no longer used in the name of a
        resulting type variable. Before: `_foo` => `w_foo`, now: `_foo` => `t`
        or `a`.
      
      Test Plan: generate the users guide
      
      Reviewers: goldfire, austin, bgamari
      
      Reviewed By: bgamari
      
      Subscribers: thomie
      
      Differential Revision: https://phabricator.haskell.org/D2413
      
      GHC Trac Issues: #12365
      627c767b
  10. 04 Jul, 2016 1 commit
  11. 01 Jul, 2016 1 commit
  12. 27 Jun, 2016 1 commit
  13. 23 Jun, 2016 1 commit
    • Simon Peyton Jones's avatar
      Narrow the use of record wildcards slightly · 2f8cd14f
      Simon Peyton Jones authored
      In reviewing the fix to Trac #12130 I found the wild-card
      fill-in code for ".." notation in record constructions hard
      to understand.  It went to great contortions (including the
      find_tycon code) to allow
          data T = C { x, y :: Int }
          f x = C { .. }
      to expand to
          f x = C { x = x, y = y }
      where 'y' is an /imported function/!  That seems way over the top
      for what record wildcards are supposed to do.
      
      So I have narrowed the record-wildcard expansion to include only
      /locally-bound/ variables; i.e. not top level, and certainly not
      imported.
      
      I don't think anyone is using record wildcards in this bizarre way, so
      I don't expect any fallout. Even if there is, you can easily
      initialise fields with eponymous but imported values by hand.
      
      An intermediate position would be to allow /local/ top-level
      definitions.  But I doubt anyone is doing that either.
      
      Let's see if there's any fallout.  It's a local change, easy to
      revert, so I've just gone ahead to save everyone's time.
      2f8cd14f
  14. 21 Jun, 2016 1 commit
  15. 20 Jun, 2016 1 commit
  16. 09 Jun, 2016 2 commits
    • thomie's avatar
      Docs: delete PatternGuards documentation · c22ab1a6
      thomie authored
      Since `-XPatternGuards` is enabled by default, invert the logic and
      mention `-XNoPatternGuards` first.
      
      Also, since this is a Haskell 2010 feature, refer to the language report
      instead of explaining it.
      
      In general, I would like to follow the guideline of assuming the latest
      language report as a given, and then only report GHC's deviations and
      extensions relative to that report.
      
      Reviewed by: bgamari
      
      Differential Revision: https://phabricator.haskell.org/D2319
      
      GHC Trac Issues: #12172
      c22ab1a6
    • thomie's avatar
      Docs: fix links to ghc-flags · e703a232
      thomie authored
      e703a232
  17. 27 May, 2016 1 commit
  18. 25 May, 2016 1 commit
  19. 24 May, 2016 2 commits
  20. 19 May, 2016 1 commit
  21. 12 May, 2016 1 commit
    • Ryan Scott's avatar
      Make Generic1 poly-kinded · b8e25651
      Ryan Scott authored
      This generalizes the `Generic1` typeclass to be of kind `k -> *`, and
      this also makes the relevant datatypes and typeclasses in `GHC.Generics`
      poly-kinded. If `PolyKinds` is enabled, `DeriveGeneric` derives
      `Generic1` instances such that they use the most general kind possible.
      Otherwise, deriving `Generic1` defaults to make an instance where the
      argument is of kind `* -> *` (the current behavior).
      
      Fixes #10604. Depends on D2117.
      
      Test Plan: ./validate
      
      Reviewers: kosmikus, dreixel, goldfire, austin, hvr, simonpj, bgamari
      
      Reviewed By: simonpj, bgamari
      
      Subscribers: thomie, ekmett
      
      Differential Revision: https://phabricator.haskell.org/D2168
      
      GHC Trac Issues: #10604
      b8e25651
  22. 02 May, 2016 3 commits
    • Facundo Domínguez's avatar
      StaticPointers: Allow closed vars in the static form. · 36d29f7c
      Facundo Domínguez authored
      Summary:
      With this patch closed variables are allowed regardless of whether
      they are bound at the top level or not.
      
      The FloatOut pass is always performed. When optimizations are
      disabled, only expressions that go to the top level are floated.
      Thus, the applications of the StaticPtr data constructor are always
      floated.
      
      The CoreTidy pass makes sure the floated applications appear in the
      symbol table of object files. It also collects the floated bindings
      and inserts them in the static pointer table.
      
      The renamer does not check anymore if free variables appearing in the
      static form are top-level. Instead, the typechecker looks at the
      tct_closed flag to decide if the free variables are closed.
      
      The linter checks that applications of StaticPtr only occur at the
      top of top-level bindings after the FloatOut pass.
      
      The field spInfoName of StaticPtrInfo has been removed. It used to
      contain the name of the top-level binding that contains the StaticPtr
      application. However, this information is no longer available when the
      StaticPtr is constructed, as the binding name is determined now by the
      FloatOut pass.
      
      Test Plan: ./validate
      
      Reviewers: goldfire, simonpj, austin, hvr, bgamari
      
      Reviewed By: simonpj
      
      Subscribers: thomie, mpickering, mboes
      
      Differential Revision: https://phabricator.haskell.org/D2104
      
      GHC Trac Issues: #11656
      36d29f7c
    • Sergei Trofimovich's avatar
    • Sergei Trofimovich's avatar
      glasgow_exts.rst: fix quoting · 81d8a23e
      Sergei Trofimovich authored
      glasgow_exts.rst:6525: WARNING: Inline literal start-string without end-string.
      Signed-off-by: default avatarSergei Trofimovich <siarheit@google.com>
      81d8a23e
  23. 28 Apr, 2016 1 commit
  24. 26 Apr, 2016 1 commit
  25. 19 Apr, 2016 1 commit
    • Simon Peyton Jones's avatar
      Tighten checking for associated type instances · 8136a5cb
      Simon Peyton Jones authored
      This patch finishes off Trac #11450.  Following debate on that ticket,
      the patch tightens up the rules for what the instances of an
      associated type can look like.  Now they must match the instance
      header exactly. Eg
      
         class C a b where
          type T a x b
      
      With this class decl, if we have an instance decl
        instance C ty1 ty2 where ...
      then the type instance must look like
           type T ty1 v ty2 = ...
      with exactly
        - 'ty1' for 'a'
        -  'ty2' for 'b', and
        - a variable for 'x'
      
      For example:
      
        instance C [p] Int
          type T [p] y Int = (p,y,y)
      
      Previously we allowed multiple instance equations and now, in effect,
      we don't since they would all overlap.  If you want multiple cases,
      use an auxiliary type family.
      
      This is consistent with the treatment of generic-default instances,
      and the user manual always said "WARNING: this facility (multiple
      instance equations may be withdrawn in the future".
      
      I also improved error messages, and did other minor refactoring.
      8136a5cb
  26. 17 Apr, 2016 1 commit
  27. 04 Apr, 2016 1 commit
    • Eric Seidel's avatar
      Don't infer CallStacks · 7407a66d
      Eric Seidel authored
      We originally wanted CallStacks to be opt-in, but dealing with let
      binders complicated things, forcing us to infer CallStacks. It turns
      out that the inference is actually unnecessary though, we can let the
      wanted CallStacks bubble up to the outer context by refusing to
      quantify over them. Eventually they'll be solved from a given CallStack
      or defaulted to the empty CallStack if they reach the top.
      
      So this patch prevents GHC from quantifying over CallStacks, getting us
      back to the original plan. There's a small ugliness to do with
      PartialTypeSignatures, if the partial theta contains a CallStack
      constraint, we *do* want to quantify over the CallStack; the user asked
      us to!
      
      Note that this means that
      
        foo :: _ => CallStack
        foo = getCallStack callStack
      
      will be an *empty* CallStack, since we won't infer a CallStack for the
      hole in the theta. I think this is the right move though, since we want
      CallStacks to be opt-in. One can always write
      
        foo :: (HasCallStack, _) => CallStack
        foo = getCallStack callStack
      
      to get the CallStack and still have GHC infer the rest of the theta.
      
      Test Plan: ./validate
      
      Reviewers: goldfire, simonpj, austin, hvr, bgamari
      
      Reviewed By: simonpj, bgamari
      
      Subscribers: bitemyapp, thomie
      
      Projects: #ghc
      
      Differential Revision: https://phabricator.haskell.org/D1912
      
      GHC Trac Issues: #11573
      7407a66d
  28. 30 Mar, 2016 1 commit
  29. 29 Mar, 2016 1 commit
  30. 25 Mar, 2016 2 commits
  31. 24 Mar, 2016 2 commits