1. 16 Dec, 2014 1 commit
    • Peter Wortmann's avatar
      Source notes (Core support) · 993975d3
      Peter Wortmann authored
      This patch introduces "SourceNote" tickishs that link Core to the
      source code that generated it. The idea is to retain these source code
      links throughout code transformations so we can eventually relate
      object code all the way back to the original source (which we can,
      say, encode as DWARF information to allow debugging).  We generate
      these SourceNotes like other tickshs in the desugaring phase. The
      activating command line flag is "-g", consistent with the flag other
      compilers use to decide DWARF generation.
      
      Keeping ticks from getting into the way of Core transformations is
      tricky, but doable. The changes in this patch produce identical Core
      in all cases I tested -- which at this point is GHC, all libraries and
      nofib. Also note that this pass creates *lots* of tick nodes, which we
      reduce somewhat by removing duplicated and overlapping source
      ticks. This will still cause significant Tick "clumps" - a possible
      future optimization could be to make Tick carry a list of Tickishs
      instead of one at a time.
      
      (From Phabricator D169)
      993975d3
  2. 15 Dec, 2014 1 commit
    • Simon Peyton Jones's avatar
      Make Core Lint check for locally-bound GlobalIds · d59c59f4
      Simon Peyton Jones authored
      There should be no bindings in this module for a GlobalId;
      except after CoreTidy, when top-level bindings are globalised.
      
      To check for this, I had to make the CoreToDo pass part of the
      environment that Core Lint caries.  But CoreToDo is defined in
      CoreMonad, which (before this patch) called CoreLint.
      
      So I had to do quite a bit of refactoring, moving some
      lint-invoking code into CoreLint itself.  Crucially, I also
      more tcLookupImported_maybe, importDecl, and checkwiredInTyCon
      from TcIface (which use CoreLint) to LoadIface (which doesn't).
      This is probably better structure anyway.
      
      So most of this patch is refactoring. The actual check for
      GlobalIds is in CoreLint.lintAndScopeId
      d59c59f4
  3. 03 Dec, 2014 1 commit
  4. 30 Nov, 2014 1 commit
    • Edward Z. Yang's avatar
      Filter instance visibility based on set of visible orphans, fixes #2182. · 4c834fdd
      Edward Z. Yang authored
      
      
      Summary:
      Amazingly, the fix for this very old bug is quite simple: when type-checking,
      maintain a set of "visible orphan modules" based on the orphans list of
      modules which we explicitly imported.  When we import an instance and it
      is an orphan, we check if it is in the visible modules set, and if not,
      ignore it.  A little bit of refactoring for when orphan-hood is calculated
      happens so that we always know if an instance is an orphan or not.
      
      For GHCi, we preinitialize the visible modules set based on the list of
      interactive imports which are active.
      
      Future work: Cache the visible orphan modules set for GHCi, rather than
      recomputing it every type-checking round.  (But it's tricky what to do when you
      /remove/ a module: you need a data structure a little more complicated than
      just a set of modules.)
      Signed-off-by: default avatarEdward Z. Yang <ezyang@cs.stanford.edu>
      
      Test Plan: new tests and validate
      
      Reviewers: simonpj, austin
      
      Subscribers: thomie, carter
      
      Differential Revision: https://phabricator.haskell.org/D488
      
      GHC Trac Issues: #2182
      4c834fdd
  5. 21 Nov, 2014 1 commit
    • Simon Peyton Jones's avatar
      Rejig builders for pattern synonyms, especially unlifted ones · e8762081
      Simon Peyton Jones authored
      When a pattern synonym is for an unlifted pattern, its "builder" would
      naturally be a top-level unlifted binding, which isn't allowed.  So we
      give it an extra Void# argument.
      
      Our Plan A involved then making *two* Ids for these builders, with
      some consequential fuss in the desugarer.  This was more pain than I
      liked, so I've re-jigged it.
      
       * There is just one builder for a pattern synonym.
      
       * It may have an extra Void# arg, but this decision is signalled
         by the Bool in the psBuilder field.
      
         I did the same for the psMatcher field.
      
         Both Bools are serialised into interface files, so there is
         absolutely no doubt whether that extra Void# argument is required.
      
       * I renamed "wrapper" to "builder".  We have too may "wrappers"
      
       * In order to deal with typecchecking occurrences of P in expressions,
         I refactored the tcInferId code in TcExpr.
      
      All of this allowed me to revert 5fe872
         "Apply compulsory unfoldings during desugaring, except for `seq` which is special."
      which turned out to be a rather messy hack in DsBinds
      e8762081
  6. 20 Nov, 2014 1 commit
    • Jan Stolarek's avatar
      Split SynTyCon to SynonymTyCon and FamilyTyCon · 696fc4ba
      Jan Stolarek authored
      This patch refactors internal representation of type synonyms and type families by splitting them into two separate data constructors of TyCon data type. The main motivation is is that some fields make sense only for type synonyms and some make sense only for type families. This will be even more true with the upcoming injective type families.
      
      There is also some refactoring of names to keep the naming constistent. And thus tc_kind field has become tyConKind and tc_roles has become tcRoles. Both changes are not visible from the outside of TyCon module.
      
      Updates haddock submodule
      
      Reviewers: simonpj
      
      Differential Revision: https://phabricator.haskell.org/D508
      
      GHC Trac Issues: #9812
      696fc4ba
  7. 18 Nov, 2014 1 commit
  8. 13 Nov, 2014 1 commit
  9. 08 Nov, 2014 1 commit
  10. 02 Nov, 2014 1 commit
  11. 31 Oct, 2014 1 commit
  12. 24 Oct, 2014 1 commit
    • Edward Z. Yang's avatar
      Implementation of hsig (module signatures), per #9252 · aa479953
      Edward Z. Yang authored
      
      
      Summary:
      Module signatures, like hs-boot files, are Haskell modules which omit
      value definitions and contain only signatures.  This patchset implements
      one particular aspect of module signature, namely compiling them against
      a concrete implementation.  It works like this: when we compile an hsig
      file, we must be told (via the -sig-of flag) what module this signature
      is implementing.  The signature is compiled into an interface file which
      reexports precisely the entities mentioned in the signature file.  We also
      verify that the interface is compatible with the implementation.
      
      This feature is useful in a few situations:
      
          1. Like explicit import lists, signatures can be used to reduce
          sensitivity to upstream changes.  However, a signature can be defined
          once and then reused by many modules.
      
          2. Signatures can be used to quickly check if a new upstream version
          is compatible, by typechecking just the signatures and not the actual
          modules.
      
          3. A signature can be used to mediate separate modular development,
          where the signature is used as a placeholder for functionality which
          is loaded in later.  (This is only half useful at the moment, since
          typechecking against signatures without implementations is not implemented
          in this patchset.)
      
      Unlike hs-boot files, hsig files impose no performance overhead.
      
      This patchset punts on the type class instances (and type families) problem:
      instances simply leak from the implementation to the signature.  You can
      explicitly specify what instances you expect to have, and those will be checked,
      but you may get more instances than you asked for.  Our eventual plan is
      to allow hiding instances, but to consider all transitively reachable instances
      when considering overlap and soundness.
      
      ToDo: signature merging: when a module is provided by multiple signatures
      for the same base implementation, we should not consider this ambiguous.
      
      ToDo: at the moment, signatures do not constitute use-sites, so if you
      write a signature for a deprecated function, you won't get a warning
      when you compile the signature.
      
      Future work: The ability to feed in shaping information so that we can take
      advantage of more type equalities than might be immediately evident.
      Signed-off-by: default avatarEdward Z. Yang <ezyang@cs.stanford.edu>
      
      Test Plan: validate and new tests
      
      Reviewers: simonpj, simonmar, hvr, austin
      
      Subscribers: simonmar, relrod, ezyang, carter, goldfire
      
      Differential Revision: https://phabricator.haskell.org/D130
      
      GHC Trac Issues: #9252
      aa479953
  13. 24 Sep, 2014 1 commit
  14. 21 Sep, 2014 1 commit
  15. 28 Aug, 2014 1 commit
    • Simon Peyton Jones's avatar
      Refactor unfoldings · 6e0f6ede
      Simon Peyton Jones authored
      There are two main refactorings here
      
      1.  Move the uf_arity field
             out of CoreUnfolding
             into UnfWhen
          It's a lot tidier there.  If I've got this right, no behaviour
          should change.
      
      2.  Define specUnfolding and use it in DsBinds and Specialise
           a) commons-up some shared code
           b) makes sure that Specialise correctly specialises DFun
              unfoldings (which it didn't before)
      
      The two got put together because both ended up interacting in the
      specialiser.
      
      They cause zero difference to nofib.
      6e0f6ede
  16. 15 Jul, 2014 1 commit
    • Simon Peyton Jones's avatar
      Entirely re-jig the handling of default type-family instances (fixes Trac #9063) · 9b8ba629
      Simon Peyton Jones authored
      In looking at Trac #9063 I decided to re-design the default
      instances for associated type synonyms.  Previously it was all
      jolly complicated, to support generality that no one wanted, and
      was arguably undesirable.
      
      Specifically
      
      * The default instance for an associated type can have only
        type variables on the LHS.  (Not type patterns.)
      
      * There can be at most one default instances declaration for
        each associated type.
      
      To achieve this I had to do a surprisingly large amount of refactoring
      of HsSyn, specifically to parameterise HsDecls.TyFamEqn over the type
      of the LHS patterns.
      
      That change in HsDecls has a (trivial) knock-on effect in Haddock, so
      this commit does a submodule update too.
      
      The net result is good though.  The code is simpler; the language
      specification is simpler.  Happy days.
      
      Trac #9263 and #9264 are thereby fixed as well.
      9b8ba629
  17. 28 Jun, 2014 1 commit
  18. 12 Jun, 2014 1 commit
    • Simon Peyton Jones's avatar
      Improve IfaceSyn a bit further · a600c913
      Simon Peyton Jones authored
      This patch has three main bits:
      
      * The most substantial change is that IfaceConDecl no longer
        records its universal type variables, because they are
        always the same as those of the parent TyCon.  A bit less
        fuss and clutter.
      
      * Add a synonym for IfTopBndr = OccName, and explain why it's an
        OccName not a FastString
      
      * Make the ifMinDef field be a (BooleanFormula IfLclName) rather
        than (BooleanFormula OccName).  These really are occurrences (not
        binders), and should be treated like other occurences.
      
      The first and third change the format of interface files, so
      you'll need to recompile.
      a600c913
  19. 07 Jun, 2014 1 commit
  20. 03 Jun, 2014 2 commits
    • Simon Peyton Jones's avatar
      Use IfLclName instead of OccName in IfaceEqSpec · 6e8861c9
      Simon Peyton Jones authored
      The type variables in the IfaceEqSpec of a data constructor are really
      ordinarly *occurrences*, so they should be IfLclNames just like any
      other type variable occurence.
      6e8861c9
    • Simon Peyton Jones's avatar
      Do pretty-printing of TyThings via IfaceDecl (Trac #7730) · b4856f9f
      Simon Peyton Jones authored
      All the initial work on this was done fy 'archblob' (fcsernik@gmail.com);
      thank you!
      
      I reviewed the patch, started some tidying, up and then ended up in a huge
      swamp of changes, not all of which I can remember now.  But:
      
      * To suppress kind arguments when we have -fno-print-explicit-kinds,
          - IfaceTyConApp argument types are in a tagged list IfaceTcArgs
      
      * To allow overloaded types to be printed with =>, add IfaceDFunTy to IfaceType.
      
      * When printing data/type family instances for the user, I've made them
        print out an informative RHS, which is a new feature. Thus
              ghci> info T
              data family T a
              data instance T Int = T1 Int Int
              data instance T Bool = T2
      
      * In implementation terms, pprIfaceDecl has just one "context" argument,
        of type IfaceSyn.ShowSub, which says
             - How to print the binders of the decl
               see note [Printing IfaceDecl binders] in IfaceSyn
             - Which sub-comoponents (eg constructors) to print
      
      * Moved FastStringEnv from RnEnv to OccName
      
      It all took a ridiculously long time to do.  But it's done!
      b4856f9f
  21. 27 May, 2014 1 commit
  22. 15 May, 2014 1 commit
    • Herbert Valerio Riedel's avatar
      Add LANGUAGE pragmas to compiler/ source files · 23892440
      Herbert Valerio Riedel authored
      In some cases, the layout of the LANGUAGE/OPTIONS_GHC lines has been
      reorganized, while following the convention, to
      
      - place `{-# LANGUAGE #-}` pragmas at the top of the source file, before
        any `{-# OPTIONS_GHC #-}`-lines.
      
      - Moreover, if the list of language extensions fit into a single
        `{-# LANGUAGE ... -#}`-line (shorter than 80 characters), keep it on one
        line. Otherwise split into `{-# LANGUAGE ... -#}`-lines for each
        individual language extension. In both cases, try to keep the
        enumeration alphabetically ordered.
        (The latter layout is preferable as it's more diff-friendly)
      
      While at it, this also replaces obsolete `{-# OPTIONS ... #-}` pragma
      occurences by `{-# OPTIONS_GHC ... #-}` pragmas.
      23892440
  23. 08 May, 2014 1 commit
  24. 03 May, 2014 1 commit
  25. 22 Mar, 2014 1 commit
    • eir@cis.upenn.edu's avatar
      Remove redundant compatibility check. · b0bcbc04
      eir@cis.upenn.edu authored
      Previously, the closed type family compatibility check was
      done even when type-checking an interface file. But interface
      files now store compatibility info, so this check was redundant.
      b0bcbc04
  26. 20 Jan, 2014 1 commit
    • Gergő Érdi's avatar
      Implement pattern synonyms · 4f8369bf
      Gergő Érdi authored
      This patch implements Pattern Synonyms (enabled by -XPatternSynonyms),
      allowing y ou to assign names to a pattern and abstract over it.
      
      The rundown is this:
      
        * Named patterns are introduced by the new 'pattern' keyword, and can
          be either *unidirectional* or *bidirectional*. A unidirectional
          pattern is, in the simplest sense, simply an 'alias' for a pattern,
          where the LHS may mention variables to occur in the RHS. A
          bidirectional pattern synonym occurs when a pattern may also be used
          in expression context.
      
        * Unidirectional patterns are declared like thus:
      
              pattern P x <- x:_
      
          The synonym 'P' may only occur in a pattern context:
      
              foo :: [Int] -> Maybe Int
              foo (P x) = Just x
              foo _     = Nothing
      
        * Bidirectional patterns are declared like thus:
      
              pattern P x y = [x, y]
      
          Here, P may not only occur as a pattern, but also as an expression
          when given values for 'x' and 'y', i.e.
      
              bar :: Int -> [Int]
              bar x = P x 10
      
        * Patterns can't yet have their own type signatures; signatures are inferred.
      
        * Pattern synonyms may not be recursive, c.f. type synonyms.
      
        * Pattern synonyms are also exported/imported using the 'pattern'
          keyword in an import/export decl, i.e.
      
              module Foo (pattern Bar) where ...
      
          Note that pattern synonyms share the namespace of constructors, so
          this disambiguation is required as a there may also be a 'Bar'
          type in scope as well as the 'Bar' pattern.
      
        * The semantics of a pattern synonym differ slightly from a typical
          pattern: when using a synonym, the pattern itself is matched,
          followed by all the arguments. This means that the strictness
          differs slightly:
      
              pattern P x y <- [x, y]
      
              f (P True True) = True
              f _             = False
      
              g [True, True] = True
              g _            = False
      
          In the example, while `g (False:undefined)` evaluates to False,
          `f (False:undefined)` results in undefined as both `x` and `y`
          arguments are matched to `True`.
      
      For more information, see the wiki:
      
          https://ghc.haskell.org/trac/ghc/wiki/PatternSynonyms
          https://ghc.haskell.org/trac/ghc/wiki/PatternSynonyms/Implementation
      
      Reviewed-by: Simon Peyton Jones's avatarSimon Peyton Jones <simonpj@microsoft.com>
      Signed-off-by: default avatarAustin Seipp <austin@well-typed.com>
      4f8369bf
  27. 05 Nov, 2013 1 commit
  28. 18 Oct, 2013 2 commits
  29. 20 Sep, 2013 1 commit
    • Simon Peyton Jones's avatar
      Refactor AMP warnings a bit · e17072d1
      Simon Peyton Jones authored
      There was a bit of clutter (tryTc stuff) caused by the
      fact that tcLookupImported didn't return a MaybeErr.
      Now it does.  That finishes up Trac #8004.
      e17072d1
  30. 18 Sep, 2013 1 commit
  31. 13 Sep, 2013 1 commit
    • Iavor S. Diatchki's avatar
      Add support for evaluation of type-level natural numbers. · 1f77a534
      Iavor S. Diatchki authored
      This patch implements some simple evaluation of type-level expressions
      featuring natural numbers.  We can evaluate *concrete* expressions that
      use the built-in type families (+), (*), (^), and (<=?), declared in
      GHC.TypeLits.   We can also do some type inference involving these
      functions.  For example, if we encounter a constraint such as `(2 + x) ~ 5`
      we can infer that `x` must be 3.  Note, however, this is used only to
      resolve unification variables (i.e., as a form of a constraint improvement)
      and not to generate new facts.  This is similar to how functional
      dependencies work in GHC.
      
      The patch adds a new form of coercion, `AxiomRuleCo`, which makes use
      of a new form of axiom called `CoAxiomRule`.  This is the form of evidence
      generate when we solve a constraint, such as `(1 + 2) ~ 3`.
      
      The patch also adds support for built-in type-families, by adding a new
      form of TyCon rhs: `BuiltInSynFamTyCon`.  such built-in type-family
      constructors contain a record with functions that are used by the
      constraint solver to simplify and improve constraints involving the
      built-in function (see `TcInteract`).  The record in defined in `FamInst`.
      
      The type constructors and rules for evaluating the type-level functions
      are in a new module called `TcTypeNats`.
      1f77a534
  32. 04 Sep, 2013 1 commit
  33. 02 Sep, 2013 1 commit
    • Simon Peyton Jones's avatar
      Remove the final vestiges of InlineWrappers · e4a1d2d0
      Simon Peyton Jones authored
      Part of Nick Frisby's patch (c080f727)
      for late demand-analysis removed the over-zealous short-cut whereby
      strictness wrappers were not spelled out in detail in interface files.
      
      This patch completes the process by
       * removing InlineWrapper from UnfoldingSource
       * removing IfWrapper from IfaceUnfolding
      
      There was a tiny bit of special ad-hocery for wrappers, in OccurAnal,
      but fortunately that too turns out to be rendered irrelevant by
      the more uniform treatment, and after that there was no need
      to remember which functions are wrappers.
      e4a1d2d0
  34. 29 Aug, 2013 1 commit
  35. 05 Aug, 2013 1 commit
  36. 02 Aug, 2013 1 commit
  37. 24 Jun, 2013 1 commit
  38. 21 Jun, 2013 1 commit
    • eir@cis.upenn.edu's avatar
      Revise implementation of overlapping type family instances. · 569b2652
      eir@cis.upenn.edu authored
      This commit changes the syntax and story around overlapping type
      family instances. Before, we had "unbranched" instances and
      "branched" instances. Now, we have closed type families and
      open ones.
      
      The behavior of open families is completely unchanged. In particular,
      coincident overlap of open type family instances still works, despite
      emails to the contrary.
      
      A closed type family is declared like this:
      > type family F a where
      >   F Int = Bool
      >   F a   = Char
      The equations are tried in order, from top to bottom, subject to
      certain constraints, as described in the user manual. It is not
      allowed to declare an instance of a closed family.
      569b2652