[commit: ghc] master: Warn when a SPECIALISE pragma gives rise to a totally inactive rule (6acf6cd)

[Simon Peyton-Jones]

Ian

Fixed... but I had to add

{-# OPTIONS_GHC -Wwarn #-}

to containers:Data.Sequence

because it contains stuff like

{-# INLINE deep #-}
{-# SPECIALIZE INLINE deep :: Digit (Elem a) -> FingerTree (Node (Elem a)) -> Digit (Elem a) -> FingerTree (Elem a) #-}

And the SPECIALISE really is wrong there... you should either specialise or inline. Not sure which is wanted, but warning about using both is right.

I don't know the protocol for updating containers, so I'm just telling you!  Can you do something so that everyone doesn't fall over on this?

Simon
| -----Original Message-----
| From: Ian Lynagh [mailto:igloo at earth.li]
| Sent: 18 January 2012 12:49
| To: Simon Peyton-Jones
| Cc: cvs-ghc at haskell.org
| Subject: Re: [commit: ghc] master: Warn when a SPECIALISE pragma gives rise
| to a totally inactive rule (6acf6cd)
| 
| 
| Hi Simon,
| 
| On Tue, Jan 17, 2012 at 08:02:15AM -0800, Simon Peyton-Jones wrote:
| >
| > commit 6acf6cd7a8156b40979321ff94fe836736b46175
| > Author: Simon Peyton Jones <simonpj at microsoft.com>
| > Date:   Tue Jan 17 16:01:16 2012 +0000
| >
| >     Warn when a SPECIALISE pragma gives rise to a totally inactive rule
| >     See Trac #5779
| 
| I'm getting this when validating:
| 
| "inplace/bin/ghc-stage1"   -H32m -O -Wall -Werror -H64m -O0    -package-name
| ghc-prim-0.2.0.0 -hide-all-packages -i -ilibraries/ghc-prim/. -
| ilibraries/ghc-prim/dist-install/build -ilibraries/ghc-prim/dist-
| install/build/autogen -Ilibraries/ghc-prim/dist-install/build -
| Ilibraries/ghc-prim/dist-install/build/autogen -Ilibraries/ghc-prim/.    -
| optP-include -optPlibraries/ghc-prim/dist-
| install/build/autogen/cabal_macros.h -package rts-1.0  -package-name ghc-prim
| -XHaskell98 -XCPP -XMagicHash -XForeignFunctionInterface -XUnliftedFFITypes -
| XUnboxedTuples -XEmptyDataDecls -XNoImplicitPrelude -O2 -O -dcore-lint -fno-
| warn-deprecated-flags  -no-user-package-conf -rtsopts     -odir
| libraries/ghc-prim/dist-install/build -hidir libraries/ghc-prim/dist-
| install/build -stubdir libraries/ghc-prim/dist-install/build -hisuf hi -osuf
| o -hcsuf hc -c libraries/ghc-prim/./GHC/Classes.hs -o libraries/ghc-
| prim/dist-install/build/GHC/Classes.o
| *** Core Lint warnings : in result of Desugar (after optimization) ***
| {-# LINE 46 "libraries/ghc-prim/GHC/Classes.hs #-}: Warning:
|     [RHS of $c/=_a1oD :: forall a_a8L.
|                          GHC.Classes.Eq a_a8L =>
|                          [a_a8L] -> [a_a8L] -> GHC.Types.Bool]
|     INLINE binder is (non-rule) loop breaker: $c/=_a1oD
| {-# LINE 46 "libraries/ghc-prim/GHC/Classes.hs #-}: Warning:
|     [RHS of $c/=_a1oi :: GHC.Types.Float
|                          -> GHC.Types.Float -> GHC.Types.Bool]
|     INLINE binder is (non-rule) loop breaker: $c/=_a1oi
| {-# LINE 46 "libraries/ghc-prim/GHC/Classes.hs #-}: Warning:
|     [RHS of $c/=_a1ob :: GHC.Types.Double
|                          -> GHC.Types.Double -> GHC.Types.Bool]
|     INLINE binder is (non-rule) loop breaker: $c/=_a1ob
| 
| 
| libraries/ghc-prim/GHC/Classes.hs:88:5: Warning:
|     SPECIALISE pragma on INLINE function probably won't fire: `$c/='
| 
| <no location info>:
| Failing due to -Werror.
| make[1]: *** [libraries/ghc-prim/dist-install/build/GHC/Classes.o] Error 1
| make: *** [all] Error 2
| 
| 
| 
| Thanks
| Ian
|