diff options
Diffstat (limited to 'compiler')
| -rw-r--r-- | compiler/typecheck/TcTyClsDecls.lhs | 29 |
1 files changed, 16 insertions, 13 deletions
diff --git a/compiler/typecheck/TcTyClsDecls.lhs b/compiler/typecheck/TcTyClsDecls.lhs index 743bd7c30c..40ed8983c1 100644 --- a/compiler/typecheck/TcTyClsDecls.lhs +++ b/compiler/typecheck/TcTyClsDecls.lhs @@ -1180,25 +1180,28 @@ conRepresentibleWithH98Syntax -- and reboxing more complicated chooseBoxingStrategy :: TcType -> HsBang -> TcM HsBang chooseBoxingStrategy arg_ty bang - = case bang of - HsNoBang -> return HsNoBang - HsStrict -> do { unbox_strict <- doptM Opt_UnboxStrictFields - ; if unbox_strict then return (can_unbox HsStrict arg_ty) - else return HsStrict } - HsNoUnpack -> return HsStrict - HsUnpack -> do { omit_prags <- doptM Opt_OmitInterfacePragmas - ; let bang = can_unbox HsUnpackFailed arg_ty - ; if omit_prags && bang == HsUnpack - then return HsStrict - else return bang } + = do { dflags <- getDynFlags + ; let choice = case bang of + HsNoBang -> HsNoBang + HsStrict | dopt Opt_UnboxStrictFields dflags + -> can_unbox HsStrict arg_ty + | otherwise -> HsStrict + HsNoUnpack -> HsStrict + HsUnpack -> can_unbox HsUnpackFailed arg_ty + HsUnpackFailed -> pprPanic "chooseBoxingStrategy" (ppr arg_ty) + -- Source code never has HsUnpackFailed + + ; case choice of + HsUnpack | dopt Opt_OmitInterfacePragmas dflags + -> return HsStrict + _other -> return choice -- Do not respect UNPACK pragmas if OmitInterfacePragmas is on -- See Trac #5252: unpacking means we must not conceal the -- representation of the argument type -- However: even when OmitInterfacePragmas is on, we still want -- to know if we have HsUnpackFailed, because we omit a -- warning in that case (#3966) - HsUnpackFailed -> pprPanic "chooseBoxingStrategy" (ppr arg_ty) - -- Source code never has shtes + } where can_unbox :: HsBang -> TcType -> HsBang -- Returns HsUnpack if we can unpack arg_ty |