1. 23 Apr, 2020 4 commits
  2. 18 Apr, 2020 2 commits
  3. 07 Apr, 2020 1 commit
  4. 29 Mar, 2020 1 commit
  5. 18 Mar, 2020 1 commit
  6. 17 Mar, 2020 1 commit
  7. 15 Mar, 2020 1 commit
  8. 26 Feb, 2020 1 commit
  9. 22 Feb, 2020 1 commit
  10. 14 Feb, 2020 1 commit
  11. 07 Jan, 2020 1 commit
  12. 30 Nov, 2019 1 commit
  13. 19 Nov, 2019 1 commit
    • Ben Gamari's avatar
      Give seq a more precise type and remove magic · 08d595c0
      Ben Gamari authored
      `GHC.Prim.seq` previously had the rather plain type:
      
          seq :: forall a b. a -> b -> b
      
      However, it also had a special typing rule to applications
      where `b` is not of kind `Type`.
      
      Issue #17440 noted that levity polymorphism allows us to rather give
      it the more precise type:
      
          seq :: forall (r :: RuntimeRep) a (b :: TYPE r). a -> b -> b
      
      This allows us to remove the special typing rule that we previously
      required to allow applications on unlifted arguments. T9404 contains a
      non-Type application of `seq` which should verify that this works as
      expected.
      
      Closes #17440.
      08d595c0
  14. 03 Nov, 2019 1 commit
    • Sebastian Graf's avatar
      Separate `LPat` from `Pat` on the type-level · 182b1199
      Sebastian Graf authored
      Since the Trees That Grow effort started, we had `type LPat = Pat`.
      This is so that `SrcLoc`s would only be annotated in GHC's AST, which is
      the reason why all GHC passes use the extension constructor `XPat` to
      attach source locations. See #15495 for the design discussion behind
      that.
      
      But now suddenly there are `XPat`s everywhere!
      There are several functions which dont't cope with `XPat`s by either
      crashing (`hsPatType`) or simply returning incorrect results
      (`collectEvVarsPat`).
      
      This issue was raised in #17330. I also came up with a rather clean and
      type-safe solution to the problem: We define
      
      ```haskell
      type family XRec p (f :: * -> *) = r | r -> p f
      type instance XRec (GhcPass p) f = Located (f (GhcPass p))
      type instance XRec TH          f =          f p
      type LPat p = XRec p Pat
      ```
      
      This is a rather modular embedding of the old "ping-pong" style, while
      we only pay for the `Located` wrapper within GHC. No ping-ponging in
      a potential Template Haskell AST, for example. Yet, we miss no case
      where we should've handled a `SrcLoc`: `hsPatType` and
      `collectEvVarsPat` are not callable at an `LPat`.
      
      Also, this gets rid of one indirection in `Located` variants:
      Previously, we'd have to go through `XPat` and `Located` to get from
      `LPat` to the wrapped `Pat`. Now it's just `Located` again.
      
      Thus we fix #17330.
      182b1199
  15. 12 Oct, 2019 1 commit
    • Sebastian Graf's avatar
      Much simpler language for PmCheck · 30f5ac07
      Sebastian Graf authored
      Simon realised that the simple language composed of let bindings, bang
      patterns and flat constructor patterns is enough to capture the
      semantics of the source pattern language that are important for
      pattern-match checking. Well, given that the Oracle is smart enough to
      connect the dots in this less informationally dense form, which it is
      now.
      
      So we transform `translatePat` to return a list of `PmGrd`s relative to
      an incoming match variable. `pmCheck` then trivially translates each of
      the `PmGrd`s into constraints that the oracle understands.
      
      Since we pass in the match variable, we incidentally fix #15884
      (coverage checks for view patterns) through an interaction with !1746.
      30f5ac07
  16. 03 Oct, 2019 1 commit
    • Richard Eisenberg's avatar
      Note [Don't flatten tuples from HsSyn] in MkCore · 3b9d4907
      Richard Eisenberg authored
      Previously, we would sometimes flatten 1-tuples and sometimes
      not. This didn't cause damage because there is no way to
      generate HsSyn with 1-tuples. But, with the upcoming fix to #16881,
      there will be. Without this patch, obscure lint errors would
      have resulted.
      
      No test case, as there is not yet a way to tickle this.
      3b9d4907
  17. 20 Sep, 2019 2 commits
    • Simon Peyton Jones's avatar
      Fix bogus type of case expression · 0dad81ca
      Simon Peyton Jones authored
      Issue #17056 revealed that we were sometimes building a case
      expression whose type field (in the Case constructor) was bogus.
      
      Consider a phantom type synonym
         type S a = Int
      and we want to form the case expression
         case x of K (a::*) -> (e :: S a)
      We must not make the type field of the Case constructor be (S a)
      because 'a' isn't in scope.  We must instead expand the synonym.
      
      Changes in this patch:
      
      * Expand synonyms in the new function CoreUtils.mkSingleAltCase.
      
      * Use mkSingleAltCase in MkCore.wrapFloat, which was the proximate
        source of the bug (when called by exprIsConApp_maybe)
      
      * Use mkSingleAltCase elsewhere
      
      * Documentation
          CoreSyn   new invariant (6) in Note [Case expression invariants]
          CoreSyn   Note [Why does Case have a 'Type' field?]
          CoreUtils Note [Care with the type of a case expression]
      
      * I improved Core Lint's error reporting, which was pretty
        confusing in this case, because it didn't mention that the offending
        type was the return type of a case expression.
      
      * A little bit of cosmetic refactoring in CoreUtils
      0dad81ca
    • Sylvain Henry's avatar
      Module hierarchy: Hs (#13009) · 51192964
      Sylvain Henry authored
      Add GHC.Hs module hierarchy replacing hsSyn.
      
      Metric Increase:
          haddock.compiler
      51192964
  18. 09 Jul, 2019 1 commit
    • Ryan Scott's avatar
      Use an empty data type in TTG extension constructors (#15247) · 6a03d77b
      Ryan Scott authored
      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.
      6a03d77b
  19. 15 Mar, 2019 1 commit
  20. 24 Feb, 2019 1 commit
    • Simon Peyton Jones's avatar
      Add AnonArgFlag to FunTy · 6cce36f8
      Simon Peyton Jones authored
      The big payload of this patch is:
      
        Add an AnonArgFlag to the FunTy constructor
        of Type, so that
          (FunTy VisArg   t1 t2) means (t1 -> t2)
          (FunTy InvisArg t1 t2) means (t1 => t2)
      
      The big payoff is that we have a simple, local test to make
      when decomposing a type, leading to many fewer calls to
      isPredTy. To me the code seems a lot tidier, and probably
      more efficient (isPredTy has to take the kind of the type).
      
      See Note [Function types] in TyCoRep.
      
      There are lots of consequences
      
      * I made FunTy into a record, so that it'll be easier
        when we add a linearity field, something that is coming
        down the road.
      
      * Lots of code gets touched in a routine way, simply because it
        pattern matches on FunTy.
      
      * I wanted to make a pattern synonym for (FunTy2 arg res), which
        picks out just the argument and result type from the record. But
        alas the pattern-match overlap checker has a heart attack, and
        either reports false positives, or takes too long.  In the end
        I gave up on pattern synonyms.
      
        There's some commented-out code in TyCoRep that shows what I
        wanted to do.
      
      * Much more clarity about predicate types, constraint types
        and (in particular) equality constraints in kinds.  See TyCoRep
        Note [Types for coercions, predicates, and evidence]
        and Note [Constraints in kinds].
      
        This made me realise that we need an AnonArgFlag on
        AnonTCB in a TyConBinder, something that was really plain
        wrong before. See TyCon Note [AnonTCB InivsArg]
      
      * When building function types we must know whether we
        need VisArg (mkVisFunTy) or InvisArg (mkInvisFunTy).
        This turned out to be pretty easy in practice.
      
      * Pretty-printing of types, esp in IfaceType, gets
        tidier, because we were already recording the (->)
        vs (=>) distinction in an ad-hoc way.  Death to
        IfaceFunTy.
      
      * mkLamType needs to keep track of whether it is building
        (t1 -> t2) or (t1 => t2).  See Type
        Note [mkLamType: dictionary arguments]
      
      Other minor stuff
      
      * Some tidy-up in validity checking involving constraints;
        Trac #16263
      6cce36f8
  21. 24 Nov, 2018 1 commit
  22. 22 Nov, 2018 1 commit
    • Sylvain Henry's avatar
      Rename literal constructors · 13bb4bf4
      Sylvain Henry authored
      In a previous patch we replaced some built-in literal constructors
      (MachInt, MachWord, etc.) with a single LitNumber constructor.
      
      In this patch we replace the `Mach` prefix of the remaining constructors
      with `Lit` for consistency (e.g., LitChar, LitLabel, etc.).
      
      Sadly the name `LitString` was already taken for a kind of FastString
      and it would become misleading to have both `LitStr` (literal
      constructor renamed after `MachStr`) and `LitString` (FastString
      variant). Hence this patch renames the FastString variant `PtrString`
      (which is more accurate) and the literal string constructor now uses the
      least surprising `LitString` name.
      
      Both `Literal` and `LitString/PtrString` have recently seen breaking
      changes so doing this kind of renaming now shouldn't harm much.
      
      Reviewers: hvr, goldfire, bgamari, simonmar, jrtc27, tdammers
      
      Subscribers: tdammers, rwbarton, thomie, carter
      
      Differential Revision: https://phabricator.haskell.org/D4881
      13bb4bf4
  23. 21 Aug, 2018 1 commit
    • Andreas Klebinger's avatar
      Replace most occurences of foldl with foldl'. · 09c1d5af
      Andreas Klebinger authored
      This patch adds foldl' to GhcPrelude and changes must occurences
      of foldl to foldl'. This leads to better performance especially
      for quick builds where GHC does not perform strictness analysis.
      
      It does change strictness behaviour when we use foldl' to turn
      a argument list into function applications. But this is only a
      drawback if code looks ONLY at the last argument but not at the first.
      And as the benchmarks show leads to fewer allocations in practice
      at O2.
      
      Compiler performance for Nofib:
      
      O2 Allocations:
              -1 s.d.                -----            -0.0%
              +1 s.d.                -----            -0.0%
              Average                -----            -0.0%
      
      O2 Compile Time:
              -1 s.d.                -----            -2.8%
              +1 s.d.                -----            +1.3%
              Average                -----            -0.8%
      
      O0 Allocations:
              -1 s.d.                -----            -0.2%
              +1 s.d.                -----            -0.1%
              Average                -----            -0.2%
      
      Test Plan: ci
      
      Reviewers: goldfire, bgamari, simonmar, tdammers, monoidal
      
      Reviewed By: bgamari, monoidal
      
      Subscribers: tdammers, rwbarton, thomie, carter
      
      Differential Revision: https://phabricator.haskell.org/D4929
      09c1d5af
  24. 30 Jul, 2018 1 commit
    • Ryan Scott's avatar
      Fix #15385 by using addDictsDs in matchGuards · 9d388eb8
      Ryan Scott authored
      Summary:
      When coverage checking pattern-matches, we rely on the call
      sites in the desugarer to populate the local dictionaries and term
      evidence in scope using `addDictsDs` and `addTmCsDs`. But it turns
      out that only the call site for desugaring `case` expressions was
      actually doing this properly. In another part of the desugarer,
      `matchGuards` (which handles pattern guards), it did not update the
      local dictionaries in scope at all, leading to #15385.
      
      Fixing this is relatively straightforward: just augment the
      `BindStmt` case of `matchGuards` to use `addDictsDs` and `addTmCsDs`.
      Accomplishing this took a little bit of import/export tweaking:
      
      * We now need to export `collectEvVarsPat` from `HsPat.hs`.
      * To avoid an import cycle with `Check.hs`, I moved `isTrueLHsExpr`
        from `DsGRHSs.hs` to `DsUtils.hs`, which resides lower on the
        import chain.
      
      Test Plan: make test TEST=T15385
      
      Reviewers: simonpj, bgamari
      
      Reviewed By: simonpj
      
      Subscribers: rwbarton, thomie, carter
      
      GHC Trac Issues: #15385
      
      Differential Revision: https://phabricator.haskell.org/D4968
      9d388eb8
  25. 27 Jul, 2018 1 commit
    • Simon Peyton Jones's avatar
      Small refactor in desugar of pattern matching · 45cfe651
      Simon Peyton Jones authored
      In reviewing Phab:D4968 for Trac #15385 I saw a small
      but simple refactor to avoid unnecessary work in the
      desugarer.
      
      This patch just arranges to call
         matchSinglePatVar v ...
      rather than
         matchSinglePat (Var v) ...
      
      The more specialised function already existed, as
         match_single_pat_var
      
      I also added more comments about decideBangHood
      45cfe651
  26. 02 Jun, 2018 1 commit
    • Ben Gamari's avatar
      vectorise: Put it out of its misery · faee23bb
      Ben Gamari authored
      Poor DPH and its vectoriser have long been languishing; sadly it seems there is
      little chance that the effort will be rekindled. Every few years we discuss
      what to do with this mass of code and at least once we have agreed that it
      should be archived on a branch and removed from `master`. Here we do just that,
      eliminating heaps of dead code in the process.
      
      Here we drop the ParallelArrays extension, the vectoriser, and the `vector` and
      `primitive` submodules.
      
      Test Plan: Validate
      
      Reviewers: simonpj, simonmar, hvr, goldfire, alanz
      
      Reviewed By: simonmar
      
      Subscribers: goldfire, rwbarton, thomie, mpickering, carter
      
      Differential Revision: https://phabricator.haskell.org/D4761
      faee23bb
  27. 09 Apr, 2018 1 commit
  28. 15 Jan, 2018 1 commit
    • David Feuer's avatar
      Kill off irrefutable pattern errors · 492e6044
      David Feuer authored
      Distinguishing between "refutable" and "irrefutable" patterns
      (as described by the Haskell Report) in incomplete pattern errors
      was more confusing than helpful. Remove references to irrefutable
      patterns.
      
      Reviewers: hvr, bgamari, simonpj
      
      Reviewed By: simonpj
      
      Subscribers: simonpj, rwbarton, thomie, carter
      
      GHC Trac Issues: #14569
      
      Differential Revision: https://phabricator.haskell.org/D4261
      492e6044
  29. 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
  30. 08 Nov, 2017 1 commit
  31. 07 Nov, 2017 2 commits
  32. 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
  33. 29 Aug, 2017 1 commit
    • Simon Peyton Jones's avatar
      Small refactor of getRuntimeRep · a6c448b4
      Simon Peyton Jones authored
      Instead of using a string argument, use HasDebugCallStack.
      (Oddly, some functions were using both!)
      
      Plus, use getRuntimeRep rather than getRuntimeRep_maybe when
      if the caller panics on Nothing. Less code, and a better debug
      stack.
      a6c448b4
  34. 27 Jun, 2017 1 commit