Marge Bot pushed to branch master at Glasgow Haskell Compiler / GHC

Commits:

9 changed files:

Changes:

  • changelog.d/T27764
    1 
    +section: compiler
    2 
    +synopsis: Fix bug in ``static`` forms
    3 
    +issues: #27664
    4 
    +mrs: !16624
    5 
    +description: A ``static`` form should have no free *term* variables, but it
    6 
    +  can have free *type* variables.  Alas, the renamer does not really know what
    7 
    +  is a term variable and what is a type variable, because of required type
    8 
    +  arguments. This patch moves the test to the typechecker, which does know.

  • compiler/GHC/Hs/Expr.hs
    ... ... @@ -39,6 +39,7 @@ import GHC.Tc.Types.ErrCtxt
    39 39 
     import GHC.Types.Id.Info ( RecSelParent )
    40 40 
     import GHC.Types.Name
    41 41 
     import GHC.Types.Name.Reader
    42 
    +import GHC.Types.Name.Set( FreeNames )
    42 43 
     import GHC.Types.Basic
    43 44 
     import GHC.Types.Fixity
    44 45 
     import GHC.Types.SourceText
    ... ... @@ -363,7 +364,9 @@ type instance XArithSeq GhcTc = PostTcExpr
    363 364 
     type instance XProc          (GhcPass _) = (EpToken "proc", TokRarrow)
    364 365
    365 366 
     type instance XStatic        GhcPs = EpToken "static"
    366 
    -type instance XStatic        GhcRn = NoExtField
    367 
    +type instance XStatic        GhcRn = FreeNames
    368 
    +  -- Free variables of the body; we can't tell if they are
    369 
    +  -- type or term variables until we are typechecking
    367 370 
     type instance XStatic        GhcTc = (Type, HsExpr GhcTc)
    368 371 
       -- Type of expression, and the (fromStaticPtr function)
    369 372 
       -- These are stored for convenience as the wiring in

  • compiler/GHC/Rename/Expr.hs
    ... ... @@ -667,18 +667,7 @@ rnExpr e@(HsStatic _ expr)
    667 667 
            -- Rename the payload
    668 668 
            ; (expr',fvs) <- rnLExpr expr
    669 669
    670 
    -       -- Check that the free variables of the static form are top-level defined
    671 
    -       -- It's OK to use nonDetEltsUniqSet here as the only side effects of
    672 
    -       -- checkClosedInStaticForm are error messages.
    673 
    -       -- See (SF2) Note [Grand plan for static forms] in GHC.Iface.Tidy.StaticPtrTable
    674 
    -       ; mapM_ check_fv (nonDetEltsUniqSet fvs)
    675 
    -
    676 
    -       ; return (HsStatic noExtField expr', fvs) }
    677 
    -  where
    678 
    -    check_fv :: Name -> RnM ()
    679 
    -    -- Check for free vars not defined at top level
    680 
    -    check_fv n = unless (isExternalName n) $
    681 
    -                 addErrTc (TcRnStaticFormNotClosed n)
    670 
    +       ; return (HsStatic fvs expr', fvs) }
    682 671
    683 672 
     {-
    684 673 
     ************************************************************************

  • compiler/GHC/Tc/Gen/Expr.hs
    ... ... @@ -602,13 +602,19 @@ tcExpr (HsProc x pat cmd) res_ty
    602 602 
     -- and wrap (static e) in a call to
    603 603 
     --    fromStaticPtr :: IsStatic p => StaticPtr a -> p a
    604 604
    605 
    -tcExpr (HsStatic _ expr) res_ty
    605 
    +tcExpr (HsStatic free_names expr) res_ty
    606 606 
       = do  { res_ty          <- expTypeToType res_ty
    607 607 
             ; (co, (p_ty, expr_ty)) <- matchExpectedAppTy res_ty
    608 608 
             ; (expr', lie) <- captureConstraints $
    609 609 
                               addErrCtxt (StaticFormCtxt expr) $
    610 610 
                               tcCheckPolyExprNC expr expr_ty
    611 611
    612 
    +        -- Check that the free variables of the static form are top-level defined
    613 
    +        -- It's OK to use nonDetEltsUniqSet here as the only side effects of
    614 
    +        -- checkClosedInStaticForm are error messages.
    615 
    +        -- See (SF2) Note [Grand plan for static forms] in GHC.Iface.Tidy.StaticPtrTable
    616 
    +        ; mapM_ check_free_name (nonDetEltsUniqSet free_names)
    617 
    +
    612 618 
             -- Emit an implication that captures the constraints of `expr`,
    613 619 
             -- but with a `ic_info` of StaticFormSkol
    614 620 
             -- See #13499 for an explanation of why this is the right thing to do:
    ... ... @@ -637,6 +643,24 @@ tcExpr (HsStatic _ expr) res_ty
    637 643 
               HsStatic (static_expr_ty, mkHsWrap wrap fromStaticPtr)
    638 644 
                        expr''
    639 645 
             }
    646 
    +  where
    647 
    +    check_free_name :: Name -> TcM ()
    648 
    +    -- Check for free /term/ vars not defined at top level
    649 
    +    -- We use isExternalName as a proxy for top-level-defined
    650 
    +    check_free_name n
    651 
    +      = do { mb_thing <- tcLookupLcl_maybe n
    652 
    +           ; case mb_thing of
    653 
    +               Nothing  -> return ()  -- Imports, tycons, classes allowed
    654 
    +               Just (ATcId {})  -> unless (isExternalName n) $
    655 
    +                                   addErrTc (TcRnStaticFormNotClosed n)
    656 
    +
    657 
    +               Just (ATyVar {}) -> return ()  -- Free type variables are allowed
    658 
    +
    659 
    +                   -- Not really expecting these, but we'll get an error from
    660 
    +                   -- elsewhere, so don't produce an error here
    661 
    +               Just (ATcTyCon {})      -> return ()
    662 
    +               Just (APromotionErr {}) -> return ()
    663 
    +               Just (AGlobal {})       -> return () }
    640 664
    641 665 
     tcExpr (HsEmbTy _ _)      _ = failWith (TcRnIllegalTypeExpr TypeKeywordSyntax)
    642 666 
     tcExpr (HsQual _ _ _)     _ = failWith (TcRnIllegalTypeExpr ContextArrowSyntax)

  • testsuite/tests/rename/should_fail/RnStaticPointersFail01.stderr
    1 1 
     RnStaticPointersFail01.hs:5:7: error: [GHC-88431]
    2 
    -    ‘x’ is used in a static form but it is not defined at top level
    2 
    +    • ‘x’ is used in a static form but it is not defined at top level
    3 
    +    • In the expression: static x
    4 
    +      In an equation for ‘f’: f x = static x
    3 5

  • testsuite/tests/rename/should_fail/RnStaticPointersFail03.stderr
    1 1 
     RnStaticPointersFail03.hs:8:7: error: [GHC-88431]
    2 
    -    ‘x’ is used in a static form but it is not defined at top level
    2 
    +    • ‘x’ is used in a static form but it is not defined at top level
    3 
    +    • In the expression: static (x . id)
    4 
    +      In an equation for ‘f’: f x = static (x . id)
    3 5
    4 6 
     RnStaticPointersFail03.hs:10:8: error: [GHC-88431]
    5 
    -    ‘k’ is used in a static form but it is not defined at top level
    7 
    +    • ‘k’ is used in a static form but it is not defined at top level
    8 
    +    • In the expression: static (k . id)
    9 
    +      In an equation for ‘f0’:
    10 
    +          f0 x
    11 
    +            = static (k . id)
    12 
    +            where
    13 
    +                k = const (const () x)
    6 14
    7 15 
     RnStaticPointersFail03.hs:14:8: error: [GHC-88431]
    8 
    -    ‘k’ is used in a static form but it is not defined at top level
    16 
    +    • ‘k’ is used in a static form but it is not defined at top level
    17 
    +    • In the expression: static (k . id)
    18 
    +      In an equation for ‘f1’:
    19 
    +          f1 x
    20 
    +            = static (k . id)
    21 
    +            where
    22 
    +                k = id
    9 23
    10 24 
     RnStaticPointersFail03.hs:19:15: error: [GHC-88431]
    11 
    -    ‘g’ is used in a static form but it is not defined at top level
    25 
    +    • ‘g’ is used in a static form but it is not defined at top level
    26 
    +    • In the first argument of ‘const’, namely ‘(static (g undefined))’
    27 
    +      In the expression: const (static (g undefined)) (h x)
    28 
    +      In an equation for ‘f2’:
    29 
    +          f2 x
    30 
    +            = const (static (g undefined)) (h x)
    31 
    +            where
    32 
    +                g = h
    33 
    +                h = typeOf
    12 34

  • testsuite/tests/rename/should_fail/T26545.stderr
    1 1 
     T26545.hs:12:23: error: [GHC-88431]
    2 
    -    ‘v’ is used in a static form but it is not defined at top level
    2 
    +    • ‘v’ is used in a static form but it is not defined at top level
    3 
    +    • In the expression: static (I# (v +# 1#))
    4 
    +      In the expression: let v = f 3# in static (I# (v +# 1#))
    5 
    +      In an equation for ‘h’: h x = let v = f 3# in static (I# (v +# 1#))
    3 6

  • testsuite/tests/typecheck/should_compile/T27664.hs
    1 
    +{-# LANGUAGE StaticPointers, ScopedTypeVariables #-}
    2 
    +module Repro where
    3 
    +
    4 
    +import Data.Typeable
    5 
    +import GHC.StaticPtr
    6 
    +
    7 
    +f1 :: forall a. Typeable a => StaticPtr (a -> a)
    8 
    +f1 = static (id :: a -> a)
    9 
    +
    10 
    +f2 :: forall a. Typeable a => StaticPtr (a -> a)
    11 
    +f2 = static (id) :: StaticPtr (a->a)

  • testsuite/tests/typecheck/should_compile/all.T
    ... ... @@ -969,3 +969,4 @@ test('ExpansionQLIm', normal, compile, [''])
    969 969 
     test('T23135', normal, compile, [''])
    970 970 
     test('LazyFieldAnnotations', normal, compile, [''])
    971 971 
     test('T27557', normal, compile, [''])
    972 
    +test('T27664', normal, compile, [''])

    • —
    View it on GitLab.
    You're receiving this email because of your account on gitlab.haskell.org. Manage all notifications · Help Notification message regarding https://gitlab.haskell.org/ghc/ghc/-/commit/c673ecf057deee858acbbaa7e6c92078a818d6f2 at 1788607425