1. 21 Dec, 2017 8 commits
    • Simon Peyton Jones's avatar
      Refactor coercion holes · a492af06
      Simon Peyton Jones authored
      In fixing Trac #14584 I found that it would be /much/ more
      convenient if a "hole" in a coercion (much like a unification
      variable in a type) acutally had a CoVar associated with it
      rather than just a Unique.  Then I can ask what the free variables
      of a coercion is, and get a set of CoVars including those
      as-yet-un-filled in holes.
      
      Once that is done, it makes no sense to stuff coercion holes
      inside UnivCo.  They were there before so we could know the
      kind and role of a "hole" coercion, but once there is a CoVar
      we can get that info from the CoVar.  So I removed HoleProv
      from UnivCoProvenance and added HoleCo to Coercion.
      
      In summary:
      
      * Add HoleCo to Coercion and remove HoleProv from UnivCoProvanance
      
      * Similarly in IfaceCoercion
      
      * Make CoercionHole have a CoVar in it, not a Unique
      
      * Make tyCoVarsOfCo return the free coercion-hole variables
        as well as the ordinary free CoVars.  Similarly, remember
        to zonk the CoVar in a CoercionHole
      
      We could go further, and remove CoercionHole as a distinct type
      altogther, just collapsing it into HoleCo.  But I have not done
      that yet.
      a492af06
    • Simon Peyton Jones's avatar
      Check for bogus quantified tyvars in partial type sigs · 72938f58
      Simon Peyton Jones authored
      This fixes Trac #14479.  Not difficult.
      
      See Note [Quantification and partial signatures] Wrinkle 4,
      in TcSimplify.
      72938f58
    • 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
    • Ryan Scott's avatar
      Improve treatment of sectioned holes · 4d41e921
      Ryan Scott authored
      Summary:
      Previously, GHC was pretty-printing left-section holes
      incorrectly and not parsing right-sectioned holes at all. This patch
      fixes both problems.
      
      Test Plan: make test TEST=T14590
      
      Reviewers: bgamari, simonpj
      
      Reviewed By: simonpj
      
      Subscribers: simonpj, rwbarton, thomie, mpickering, carter
      
      GHC Trac Issues: #14590
      
      Differential Revision: https://phabricator.haskell.org/D4273
      4d41e921
    • Ryan Scott's avatar
      Document ScopedTypeVariables' interaction with nested foralls · b6304f8f
      Ryan Scott authored
      Summary:
      This documents the status quo with regards to how
      `ScopedTypeVariables` brings into scope type variables that are
      quantified by nested `forall`s (that is to say, it doesn't). This
      takes the prose in
      https://ghc.haskell.org/trac/ghc/ticket/14288#comment:5
      and enshrines it into the users' guide.
      
      Test Plan: Read it
      
      Reviewers: simonpj, bgamari
      
      Reviewed By: simonpj
      
      Subscribers: rwbarton, thomie, carter
      
      GHC Trac Issues: #14288
      
      Differential Revision: https://phabricator.haskell.org/D4272
      b6304f8f
    • Ryan Scott's avatar
      Remove hack put in place for #12512 · 9cb289ab
      Ryan Scott authored
      Summary:
      Previously, I added an ad hoc check for unboxed tuples and
      sums in standalone-derived instances to fix #12512, under the
      pretense that polymorphism over `UnboxedTupleRep` and
      `UnboxedSumRep` was a lie. But that is no longer the case, and so
      this ad hoc check can be removed entirely. Less code, and easier to
      understand.
      
      Test Plan: make test TEST=T12512
      
      Reviewers: bgamari
      
      Reviewed By: bgamari
      
      Subscribers: rwbarton, thomie, carter
      
      Differential Revision: https://phabricator.haskell.org/D4271
      9cb289ab
    • Ryan Scott's avatar
      Fix #14588 by checking for more bang patterns · 9caf40e9
      Ryan Scott authored
      Summary:
      Commit 37299536
      inadvertently removed a check in the parser which rejected
      let-bindings with bang patterns, leading to #14588. This fixes it by
      creating a `hintBangPat` function to perform this check, and
      sprinkling it in the right places.
      
      Test Plan: make test TEST=T14588
      
      Reviewers: bgamari, alanz, simonpj
      
      Reviewed By: bgamari, simonpj
      
      Subscribers: rwbarton, thomie, mpickering, carter
      
      GHC Trac Issues: #14588
      
      Differential Revision: https://phabricator.haskell.org/D4270
      9caf40e9
    • Ryan Scott's avatar
      Fix #14578 by checking isCompoundHsType in more places · 1bd91a7a
      Ryan Scott authored
      Summary:
      The `HsType` pretty-printer does not automatically insert
      parentheses where necessary for type applications, so a function
      `isCompoundHsType` was created in D4056 towards this purpose.
      However, it was not used in as many places as it ought to be,
      resulting in #14578.
      
      Test Plan: make test TEST=T14578
      
      Reviewers: alanz, bgamari, simonpj
      
      Reviewed By: alanz, simonpj
      
      Subscribers: simonpj, rwbarton, thomie, carter
      
      GHC Trac Issues: #14578
      
      Differential Revision: https://phabricator.haskell.org/D4266
      1bd91a7a
  2. 20 Dec, 2017 1 commit
  3. 19 Dec, 2017 3 commits
  4. 18 Dec, 2017 7 commits
  5. 15 Dec, 2017 2 commits
    • Richard Eisenberg's avatar
      Add some commentary re: fix to #11203 · 3910d3e2
      Richard Eisenberg authored
      The fix for #11203 prohibits duplicate SigTvs in non-CUSK kind
      signatures by checking for duplicates after type inference is
      done. This works well. GHC also checks for duplicate SigTvs
      after working with partial type signatures (another place where
      SigTvs arise). However, neither fix eliminates this whole class
      of problems (because doing so would be heavier than we would
      like). So, this comment adds a warning to users of newSigTyVar
      to be aware of problems with duplicates.
      3910d3e2
    • Simon Peyton Jones's avatar
      Fix tcDataKindSig · 68149452
      Simon Peyton Jones authored
      This patch fixes an outright bug in tcDataKindSig, shown up in Trac
      of a data type declaration.  See Note [TyConBinders for the result kind
      signature of a data type]
      
      I also took the opportunity to elminate the DataKindCheck argument
      and data type from tcDataKindSig, instead moving the check to the
      call site, which is easier to understand.
      68149452
  6. 14 Dec, 2017 7 commits
  7. 13 Dec, 2017 7 commits
    • Gabor Greif's avatar
      Typofix in comment · 6eb32579
      Gabor Greif authored
      6eb32579
    • Simon Peyton Jones's avatar
      Further improvements to well-kinded types · 0a12d92a
      Simon Peyton Jones authored
      The typechecker has the invariant that every type should be well-kinded
      as it stands, without zonking.  See Note [The well-kinded type invariant]
      in TcType.
      
      That invariant was not being upheld, which led to Trac #14174.  I fixed
      part of it, but T14174a showed that there was more.  This patch finishes
      the job.
      
      * See Note [The tcType invariant] in TcHsType, which articulates an
        invariant that was very nearly, but not quite, true.  One place that
        falisified it was the HsWildCardTy case of tc_hs_type, so I fixed that.
      
      * mkNakedCastTy now makes no attempt to eliminate casts; indeed it cannot
        lest it break Note [The well-kinded type invariant].  The prior comment
        suggested that it was crucial for performance but happily it seems not
        to be. The extra Refls are eliminated by the zonker.
      
      * I found I could tidy up TcHsType.instantiateTyN and instantiateTyUntilN
        by eliminating one of its parameters.  That led to a cascade of minor
        improvements in TcTyClsDecls. Hooray.
      0a12d92a
    • Simon Peyton Jones's avatar
      Re-centre perf for T5321Fun · 63e968a9
      Simon Peyton Jones authored
      Bytes allocated has fallen by around 5%. I think this due
      to some of my recent refactoring of the typechecker, but
      I'm not certain about exactly which change did it.
      
      Good though!
      63e968a9
    • Simon Peyton Jones's avatar
      Add missing stderr for Trac #14561 · aef4dee8
      Simon Peyton Jones authored
      aef4dee8
    • Simon Peyton Jones's avatar
      Tidy up of wired-in names · 321b420f
      Simon Peyton Jones authored
      Two things here:
      
      * While debugging Trac #14561 I found it hard to understand
        ghcPrimIds and magicIds in MkId.  This patch adds more
        structure and comments.
      
      * I also discovered that ($) no longer needs to be a wiredInId
        because we now have levity polymorphism.  So I took dollarId
        out of MkId; and gave it a levity-polymorphic type in GHC.Base
      321b420f
    • Simon Peyton Jones's avatar
      Detect levity-polymorphic uses of unsafeCoerce# · e40db7b1
      Simon Peyton Jones authored
      This bug was shown up by Trac #14561. The deguarer carefully
      detects unsaturated and levity-polymorphic uses of primops,
      but not of things like unsafeCoerce#.
      
      The fix is simple: see Note [Levity-polymorphic Ids] in Id.
      e40db7b1
    • Simon Peyton Jones's avatar
      Minor refactor of TcExpr.tcApp · a106a200
      Simon Peyton Jones authored
      This refactoring has no change in behaviour but makes the
      structure clearer
      a106a200
  8. 12 Dec, 2017 1 commit
  9. 11 Dec, 2017 4 commits