[commit: ghc] master: put back the newtype around Label (aeaf3df)

[Simon Marlow]

Repository : ssh://darcs.haskell.org//srv/darcs/ghc

On branch  : master

http://hackage.haskell.org/trac/ghc/changeset/aeaf3df2d745eab8b7fec37cdff44deadba6fed3

>---------------------------------------------------------------

commit aeaf3df2d745eab8b7fec37cdff44deadba6fed3
Author: Simon Marlow <marlowsd at gmail.com>
Date:   Fri Jul 6 14:32:14 2012 +0100

    put back the newtype around Label
    
    Having all BlockIds print as integers was a pain for debugging.

>---------------------------------------------------------------

 compiler/cmm/BlockId.hs |    8 +++++++-
 1 files changed, 7 insertions(+), 1 deletions(-)

diff --git a/compiler/cmm/BlockId.hs b/compiler/cmm/BlockId.hs
index 4aedcb7..95293c8 100644
--- a/compiler/cmm/BlockId.hs
+++ b/compiler/cmm/BlockId.hs
@@ -15,7 +15,7 @@ import Outputable
 import Unique
 
 import Compiler.Hoopl as Hoopl hiding (Unique)
-import Compiler.Hoopl.Internals (uniqueToLbl)
+import Compiler.Hoopl.Internals (uniqueToLbl, lblToUnique)
 
 ----------------------------------------------------------------
 --- Block Ids, their environments, and their sets
@@ -31,6 +31,12 @@ compilation unit in which it appears.
 
 type BlockId = Hoopl.Label
 
+instance Uniquable BlockId where
+  getUnique label = getUnique (lblToUnique label)
+
+instance Outputable BlockId where
+  ppr label = ppr (getUnique label)
+
 mkBlockId :: Unique -> BlockId
 mkBlockId unique = uniqueToLbl $ intToUnique $ getKey unique