diff options
Diffstat (limited to 'compiler/GHC/Tc/Module.hs')
| -rw-r--r-- | compiler/GHC/Tc/Module.hs | 26 |
1 files changed, 16 insertions, 10 deletions
diff --git a/compiler/GHC/Tc/Module.hs b/compiler/GHC/Tc/Module.hs index f877e006b8..4b2c3969aa 100644 --- a/compiler/GHC/Tc/Module.hs +++ b/compiler/GHC/Tc/Module.hs @@ -103,7 +103,7 @@ import GHC.Iface.Env ( externaliseName ) import GHC.Iface.Make ( coAxiomToIfaceDecl ) import GHC.Iface.Load -import GHC.Builtin.Types ( unitTy, mkListTy ) +import GHC.Builtin.Types ( mkListTy, anyTypeOfKind ) import GHC.Builtin.Names import GHC.Builtin.Utils @@ -2172,8 +2172,8 @@ We don't bother with the tcl_th_bndrs environment either. -- | The returned [Id] is the list of new Ids bound by this statement. It can -- be used to extend the InteractiveContext via extendInteractiveContext. -- --- The returned TypecheckedHsExpr is of type IO [ () ], a list of the bound --- values, coerced to (). +-- The returned TypecheckedHsExpr is of type IO [ Any ], a list of the bound +-- values, coerced to Any. tcRnStmt :: HscEnv -> GhciLStmt GhcPs -> IO (Messages TcRnMessage, Maybe ([Id], LHsExpr GhcTc, FixityEnv)) tcRnStmt hsc_env rdr_stmt @@ -2467,13 +2467,16 @@ The reason for -fno-it is explained in #14336. `it` can lead to the repl leaking memory as it is repeatedly queried. -} +any_lifted :: Type +any_lifted = anyTypeOfKind liftedTypeKind + -- | Typecheck the statements given and then return the results of the --- statement in the form 'IO [()]'. +-- statement in the form 'IO [Any]'. tcGhciStmts :: [GhciLStmt GhcRn] -> TcM PlanResult tcGhciStmts stmts = do { ioTyCon <- tcLookupTyCon ioTyConName ; ret_id <- tcLookupId returnIOName -- return @ IO - ; let ret_ty = mkListTy unitTy + ; let ret_ty = mkListTy any_lifted io_ret_ty = mkTyConApp ioTyCon [ret_ty] tc_io_stmts = tcStmtsAndThen (HsDoStmt GhciStmtCtxt) tcDoStmt stmts (mkCheckExpType io_ret_ty) @@ -2496,28 +2499,31 @@ tcGhciStmts stmts ; traceTc "GHC.Tc.Module.tcGhciStmts: done" empty -- ret_expr is the expression - -- returnIO @[()] [unsafeCoerce# () x, .., unsafeCoerce# () z] + -- returnIO @[Any] [unsafeCoerce# @Any x, .., unsafeCoerce# @Any z] -- -- Despite the inconvenience of building the type applications etc, -- this *has* to be done in type-annotated post-typecheck form -- because we are going to return a list of *polymorphic* values - -- coerced to type (). If we built a *source* stmt + -- coerced to type Any. If we built a *source* stmt -- return [coerce x, ..., coerce z] -- then the type checker would instantiate x..z, and we wouldn't -- get their *polymorphic* values. (And we'd get ambiguity errs -- if they were overloaded, since they aren't applied to anything.) + -- + -- We use Any rather than a dummy type such as () because of + -- the rules of unsafeCoerce#; see Unsafe/Coerce.hs for the details. ; AnId unsafe_coerce_id <- tcLookupGlobal unsafeCoercePrimName -- We use unsafeCoerce# here because of (U11) in -- Note [Implementing unsafeCoerce] in base:Unsafe.Coerce ; let ret_expr = nlHsApp (nlHsTyApp ret_id [ret_ty]) $ - noLocA $ ExplicitList unitTy $ + noLocA $ ExplicitList any_lifted $ map mk_item ids mk_item id = unsafe_coerce_id `nlHsTyApp` [ getRuntimeRep (idType id) - , getRuntimeRep unitTy - , idType id, unitTy] + , getRuntimeRep any_lifted + , idType id, any_lifted] `nlHsApp` nlHsVar id stmts = tc_stmts ++ [noLocA (mkLastStmt ret_expr)] |