Don't import FastString in HsVersions.h

Modules that need it import it themselves instead.

118 files changed, 86 insertions, 116 deletions

diff --git a/compiler/HsVersions.h b/compiler/HsVersions.h
index 034a9bc07c..1ba8a01022 100644
--- a/compiler/HsVersions.h
+++ b/compiler/HsVersions.h
@@ -60,21 +60,12 @@ name = Util.global (value);
 #define WARN(e,msg)    if False && (e) then pprPanic "WARN" (msg) else
 #endif
 
--- This conditional lets us switch off the "import FastString"
--- when compiling FastString itself, or when compiling modules that
--- don't use it (and would otherwise get warnings, which we treat
--- as errors). Can we do this more nicely?
-#if !defined(COMPILING_FAST_STRING) && !defined(FAST_STRING_NOT_NEEDED)
--- 
-import qualified FastString as FS 
-#endif
-
 #if defined(__GLASGOW_HASKELL__)
-#define SLIT(x)	 (FS.mkLitString# (x#))
-#define FSLIT(x) (FS.mkFastString# (x#))
+#define SLIT(x)	 (FastString.mkLitString# (x#))
+#define FSLIT(x) (FastString.mkFastString# (x#))
 #else
-#define SLIT(x)  (FS.mkLitString (x))
-#define FSLIT(x) (FS.mkFastString (x))
+#define SLIT(x)  (FastString.mkLitString (x))
+#define FSLIT(x) (FastString.mkFastString (x))
 #endif
 
 -- Useful for declaring arguments to be strict
diff --git a/compiler/basicTypes/BasicTypes.lhs b/compiler/basicTypes/BasicTypes.lhs
index 7a9ff56cdf..d60321ade6 100644
--- a/compiler/basicTypes/BasicTypes.lhs
+++ b/compiler/basicTypes/BasicTypes.lhs
@@ -58,7 +58,7 @@ module BasicTypes(
 
 #include "HsVersions.h"
 
-import FastString( FastString )
+import FastString
 import Outputable
 \end{code}
 
diff --git a/compiler/basicTypes/IdInfo.lhs b/compiler/basicTypes/IdInfo.lhs
index 0a54395eb8..708f4dfe58 100644
--- a/compiler/basicTypes/IdInfo.lhs
+++ b/compiler/basicTypes/IdInfo.lhs
@@ -92,6 +92,7 @@ import ForeignCall
 import NewDemand
 import Outputable	
 import Module
+import FastString
 
 import Data.Maybe
 
diff --git a/compiler/basicTypes/NameEnv.lhs b/compiler/basicTypes/NameEnv.lhs
index cebabdd639..0f2023b05a 100644
--- a/compiler/basicTypes/NameEnv.lhs
+++ b/compiler/basicTypes/NameEnv.lhs
@@ -16,8 +16,6 @@ module NameEnv (
 	elemNameEnv, mapNameEnv
     ) where
 
--- XXX This define is a bit of a hack, and should be done more nicely
-#define FAST_STRING_NOT_NEEDED 1
 #include "HsVersions.h"
 
 import Name
diff --git a/compiler/basicTypes/NameSet.lhs b/compiler/basicTypes/NameSet.lhs
index 8776714580..e60ea23d27 100644
--- a/compiler/basicTypes/NameSet.lhs
+++ b/compiler/basicTypes/NameSet.lhs
@@ -22,8 +22,6 @@ module NameSet (
 	findUses, duDefs, duUses, allUses
     ) where
 
--- XXX This define is a bit of a hack, and should be done more nicely
-#define FAST_STRING_NOT_NEEDED 1
 #include "HsVersions.h"
 
 import Name
diff --git a/compiler/basicTypes/NewDemand.lhs b/compiler/basicTypes/NewDemand.lhs
index f69d2a457b..668a35e9c2 100644
--- a/compiler/basicTypes/NewDemand.lhs
+++ b/compiler/basicTypes/NewDemand.lhs
@@ -23,8 +23,6 @@ module NewDemand(
 	pprIfaceStrictSig, appIsBottom, isBottomingSig, seqStrictSig,
      ) where
 
--- XXX This define is a bit of a hack, and should be done more nicely
-#define FAST_STRING_NOT_NEEDED 1
 #include "HsVersions.h"
 
 import StaticFlags
diff --git a/compiler/basicTypes/VarEnv.lhs b/compiler/basicTypes/VarEnv.lhs
index 67bc120430..bb988b2591 100644
--- a/compiler/basicTypes/VarEnv.lhs
+++ b/compiler/basicTypes/VarEnv.lhs
@@ -46,6 +46,7 @@ import Maybes
 import Outputable
 import FastTypes
 import StaticFlags
+import FastString
 \end{code}
 
 
diff --git a/compiler/basicTypes/VarSet.lhs b/compiler/basicTypes/VarSet.lhs
index d4293ba459..d7e85674bf 100644
--- a/compiler/basicTypes/VarSet.lhs
+++ b/compiler/basicTypes/VarSet.lhs
@@ -17,8 +17,6 @@ module VarSet (
 	elemVarSetByKey
     ) where
 
--- XXX This define is a bit of a hack, and should be done more nicely
-#define FAST_STRING_NOT_NEEDED 1
 #include "HsVersions.h"
 
 import Var
diff --git a/compiler/cmm/CmmCPSGen.hs b/compiler/cmm/CmmCPSGen.hs
index 55a7397a68..0d409aba70 100644
--- a/compiler/cmm/CmmCPSGen.hs
+++ b/compiler/cmm/CmmCPSGen.hs
@@ -33,6 +33,7 @@ import StaticFlags
 import Unique
 import Maybe
 import List
+import FastString
 
 import Panic
 
diff --git a/compiler/cmm/CmmInfo.hs b/compiler/cmm/CmmInfo.hs
index 49a77e29fd..c0e217c1cc 100644
--- a/compiler/cmm/CmmInfo.hs
+++ b/compiler/cmm/CmmInfo.hs
@@ -276,6 +276,3 @@ mkStdInfoTable type_descr closure_descr cl_type srt_len layout_lit
 
     type_lit = packHalfWordsCLit cl_type srt_len
 
-
-_unused :: FS.FastString -- stops a warning
-_unused = undefined
diff --git a/compiler/cmm/CmmLint.hs b/compiler/cmm/CmmLint.hs
index e376e56d47..c4aee8adb6 100644
--- a/compiler/cmm/CmmLint.hs
+++ b/compiler/cmm/CmmLint.hs
@@ -27,6 +27,7 @@ import Outputable
 import PprCmm
 import Unique
 import Constants
+import FastString
 
 import Control.Monad
 
diff --git a/compiler/cmm/CmmOpt.hs b/compiler/cmm/CmmOpt.hs
index 4d0390d817..6adafb5feb 100644
--- a/compiler/cmm/CmmOpt.hs
+++ b/compiler/cmm/CmmOpt.hs
@@ -574,5 +574,3 @@ isComparisonExpr _other 	    = False
 isPicReg (CmmReg (CmmGlobal PicBaseReg)) = True
 isPicReg _ = False
 
-_unused :: FS.FastString -- stops a warning
-_unused = undefined
diff --git a/compiler/cmm/MachOp.hs b/compiler/cmm/MachOp.hs
index 10cc0cd04b..8f55000972 100644
--- a/compiler/cmm/MachOp.hs
+++ b/compiler/cmm/MachOp.hs
@@ -90,6 +90,7 @@ module MachOp 	(
 
 import Constants
 import Outputable
+import FastString
 
 -- -----------------------------------------------------------------------------
 -- MachRep
diff --git a/compiler/cmm/MkZipCfg.hs b/compiler/cmm/MkZipCfg.hs
index 484068ab73..067e74956c 100644
--- a/compiler/cmm/MkZipCfg.hs
+++ b/compiler/cmm/MkZipCfg.hs
@@ -360,5 +360,3 @@ Emitting a Branch at this point is fine:
 freshBlockId :: String -> UniqSM BlockId
 freshBlockId _ = do { u <- getUniqueUs; return $ BlockId u }
 
-_unused :: FS.FastString
-_unused = undefined
diff --git a/compiler/cmm/OptimizationFuel.hs b/compiler/cmm/OptimizationFuel.hs
index 6e05cdc68b..bc32626c98 100644
--- a/compiler/cmm/OptimizationFuel.hs
+++ b/compiler/cmm/OptimizationFuel.hs
@@ -48,11 +48,6 @@ oneLessFuel f = f
 diffFuel _ _ = 0
 #endif
 
--- stop warnings about things that aren't used
-_unused :: {-State#-} () -> FS.FastString
-_unused = undefined panic
-
-
 data FuelState = FuelState { fs_fuellimit :: OptimizationFuel, fs_lastpass :: String }
 newtype FuelMonad a = FuelMonad (FuelState -> (a, FuelState))
 
diff --git a/compiler/cmm/ZipCfg.hs b/compiler/cmm/ZipCfg.hs
index 1b9b5c309d..f07d2fa56e 100644
--- a/compiler/cmm/ZipCfg.hs
+++ b/compiler/cmm/ZipCfg.hs
@@ -707,5 +707,3 @@ pprGraph (Graph tail blockenv) =
     where pprBlock (Block id tail) = ppr id <> colon $$ ppr tail
           blocks = postorder_dfs_from blockenv tail
 
-_unused :: FS.FastString
-_unused = undefined
diff --git a/compiler/cmm/ZipDataflow0.hs b/compiler/cmm/ZipDataflow0.hs
index 7503d45104..00f15dbe35 100644
--- a/compiler/cmm/ZipDataflow0.hs
+++ b/compiler/cmm/ZipDataflow0.hs
@@ -1088,10 +1088,6 @@ subAnalysis' m =
   where pprFacts env = nest 2 $ vcat $ map pprFact $ ufmToList env
         pprFact (id, a) = hang (ppr id <> colon) 4 (ppr a)
 
-
-_unused :: FS.FastString
-_unused = undefined
-
 null_b_ft = BComp "do nothing" Nothing no2 no2 no2
     where no2 _ _ = Nothing
 
diff --git a/compiler/codeGen/CgBindery.lhs b/compiler/codeGen/CgBindery.lhs
index d9ddddb8bd..2ea13f6ad8 100644
--- a/compiler/codeGen/CgBindery.lhs
+++ b/compiler/codeGen/CgBindery.lhs
@@ -62,6 +62,7 @@ import StgSyn
 import Unique
 import UniqSet
 import Outputable
+import FastString
 
 \end{code}
 
diff --git a/compiler/codeGen/CgCon.lhs b/compiler/codeGen/CgCon.lhs
index 711c633fd8..b7dde73a97 100644
--- a/compiler/codeGen/CgCon.lhs
+++ b/compiler/codeGen/CgCon.lhs
@@ -52,6 +52,7 @@ import PrelInfo
 import Outputable
 import ListSetOps
 import Util
+import FastString
 \end{code}
 
 
diff --git a/compiler/codeGen/CgForeignCall.hs b/compiler/codeGen/CgForeignCall.hs
index 8e1be19beb..e9a542e5d1 100644
--- a/compiler/codeGen/CgForeignCall.hs
+++ b/compiler/codeGen/CgForeignCall.hs
@@ -43,6 +43,7 @@ import ClosureInfo
 import Constants
 import StaticFlags
 import Outputable
+import FastString
 
 import Control.Monad
 
diff --git a/compiler/codeGen/CgHeapery.lhs b/compiler/codeGen/CgHeapery.lhs
index 9cb1bb4370..4592e1964e 100644
--- a/compiler/codeGen/CgHeapery.lhs
+++ b/compiler/codeGen/CgHeapery.lhs
@@ -52,6 +52,7 @@ import Util
 import Constants
 import PackageConfig
 import Outputable
+import FastString
 
 import Data.List
 \end{code}
diff --git a/compiler/codeGen/CgPrimOp.hs b/compiler/codeGen/CgPrimOp.hs
index c77e8e5968..207ffe27d7 100644
--- a/compiler/codeGen/CgPrimOp.hs
+++ b/compiler/codeGen/CgPrimOp.hs
@@ -35,6 +35,7 @@ import PrimOp
 import SMRep
 import Constants
 import Outputable
+import FastString
 
 -- ---------------------------------------------------------------------------
 -- Code generation for PrimOps
diff --git a/compiler/codeGen/CgTailCall.lhs b/compiler/codeGen/CgTailCall.lhs
index cd100e8f21..475196abba 100644
--- a/compiler/codeGen/CgTailCall.lhs
+++ b/compiler/codeGen/CgTailCall.lhs
@@ -474,8 +474,3 @@ adjustSpAndHp newRealSp
 	}
 \end{code}
 
-Some things are unused.
-\begin{code}
-_unused :: FS.FastString
-_unused = undefined
-\end{code}
diff --git a/compiler/codeGen/SMRep.lhs b/compiler/codeGen/SMRep.lhs
index 4bc122222e..1845c449d4 100644
--- a/compiler/codeGen/SMRep.lhs
+++ b/compiler/codeGen/SMRep.lhs
@@ -53,6 +53,7 @@ import MachOp
 import StaticFlags
 import Constants
 import Outputable
+import FastString
 
 import Data.Word
 \end{code}
diff --git a/compiler/coreSyn/CoreFVs.lhs b/compiler/coreSyn/CoreFVs.lhs
index 57316c7211..7b0f027f09 100644
--- a/compiler/coreSyn/CoreFVs.lhs
+++ b/compiler/coreSyn/CoreFVs.lhs
@@ -30,8 +30,6 @@ module CoreFVs (
 	freeVarsOf		-- CoreExprWithFVs -> IdSet
     ) where
 
--- XXX This define is a bit of a hack, and should be done more nicely
-#define FAST_STRING_NOT_NEEDED 1
 #include "HsVersions.h"
 
 import CoreSyn
diff --git a/compiler/coreSyn/CoreLint.lhs b/compiler/coreSyn/CoreLint.lhs
index e903c6a39c..345fb733c7 100644
--- a/compiler/coreSyn/CoreLint.lhs
+++ b/compiler/coreSyn/CoreLint.lhs
@@ -39,6 +39,7 @@ import StaticFlags
 import ListSetOps
 import DynFlags
 import Outputable
+import FastString
 import Util
 import Data.Maybe
 \end{code}
diff --git a/compiler/coreSyn/CorePrep.lhs b/compiler/coreSyn/CorePrep.lhs
index 4d942611e3..f0c2d9fc53 100644
--- a/compiler/coreSyn/CorePrep.lhs
+++ b/compiler/coreSyn/CorePrep.lhs
@@ -35,6 +35,7 @@ import DynFlags
 import Util
 import Outputable
 import MonadUtils
+import FastString
 \end{code}
 
 -- ---------------------------------------------------------------------------
diff --git a/compiler/coreSyn/CoreSubst.lhs b/compiler/coreSyn/CoreSubst.lhs
index 503432da51..adeeaddfb2 100644
--- a/compiler/coreSyn/CoreSubst.lhs
+++ b/compiler/coreSyn/CoreSubst.lhs
@@ -43,6 +43,7 @@ import UniqSupply
 import Maybes
 import Outputable
 import PprCore		()		-- Instances
+import FastString
 
 import Data.List
 \end{code}
diff --git a/compiler/coreSyn/CoreTidy.lhs b/compiler/coreSyn/CoreTidy.lhs
index 5acee51f42..3f8402131a 100644
--- a/compiler/coreSyn/CoreTidy.lhs
+++ b/compiler/coreSyn/CoreTidy.lhs
@@ -11,8 +11,6 @@ module CoreTidy (
 	tidyExpr, tidyVarOcc, tidyRule, tidyRules 
     ) where
 
--- XXX This define is a bit of a hack, and should be done more nicely
-#define FAST_STRING_NOT_NEEDED 1
 #include "HsVersions.h"
 
 import CoreSyn
diff --git a/compiler/coreSyn/CoreUnfold.lhs b/compiler/coreSyn/CoreUnfold.lhs
index 767006076d..8da91ed924 100644
--- a/compiler/coreSyn/CoreUnfold.lhs
+++ b/compiler/coreSyn/CoreUnfold.lhs
@@ -48,6 +48,7 @@ import Type
 import PrelNames
 import Bag
 import FastTypes
+import FastString
 import Outputable
 
 \end{code}
diff --git a/compiler/deSugar/DsGRHSs.lhs b/compiler/deSugar/DsGRHSs.lhs
index 683dd2197e..83ceeca17b 100644
--- a/compiler/deSugar/DsGRHSs.lhs
+++ b/compiler/deSugar/DsGRHSs.lhs
@@ -15,8 +15,6 @@ Matching guarded right-hand-sides (GRHSs)
 
 module DsGRHSs ( dsGuarded, dsGRHSs ) where
 
--- XXX This define is a bit of a hack, and should be done more nicely
-#define FAST_STRING_NOT_NEEDED 1
 #include "HsVersions.h"
 
 import {-# SOURCE #-} DsExpr  ( dsLExpr, dsLocalBinds )
diff --git a/compiler/deSugar/DsListComp.lhs b/compiler/deSugar/DsListComp.lhs
index e5e1fd9472..03da525549 100644
--- a/compiler/deSugar/DsListComp.lhs
+++ b/compiler/deSugar/DsListComp.lhs
@@ -15,8 +15,6 @@ Desugaring list comprehensions and array comprehensions
 
 module DsListComp ( dsListComp, dsPArrComp ) where
 
--- XXX This define is a bit of a hack, and should be done more nicely
-#define FAST_STRING_NOT_NEEDED 1
 #include "HsVersions.h"
 
 import {-# SOURCE #-} DsExpr ( dsLExpr, dsLocalBinds )
diff --git a/compiler/deSugar/DsMonad.lhs b/compiler/deSugar/DsMonad.lhs
index 52b7705660..10cd28ac18 100644
--- a/compiler/deSugar/DsMonad.lhs
+++ b/compiler/deSugar/DsMonad.lhs
@@ -59,6 +59,7 @@ import OccName
 import DynFlags
 import ErrUtils
 import MonadUtils
+import FastString
 
 import Data.IORef
 \end{code}
diff --git a/compiler/deSugar/Match.lhs b/compiler/deSugar/Match.lhs
index 793cc56391..a7e9bce188 100644
--- a/compiler/deSugar/Match.lhs
+++ b/compiler/deSugar/Match.lhs
@@ -43,6 +43,7 @@ import Maybes
 import Util
 import Name
 import Outputable
+import FastString
 \end{code}
 
 This function is a wrapper of @match@, it must be called from all the parts where 
diff --git a/compiler/deSugar/MatchCon.lhs b/compiler/deSugar/MatchCon.lhs
index 3baa9666e9..4e9ee8e3f7 100644
--- a/compiler/deSugar/MatchCon.lhs
+++ b/compiler/deSugar/MatchCon.lhs
@@ -15,8 +15,6 @@ Pattern-matching constructors
 
 module MatchCon ( matchConFamily ) where
 
--- XXX This define is a bit of a hack, and should be done more nicely
-#define FAST_STRING_NOT_NEEDED 1
 #include "HsVersions.h"
 
 import {-# SOURCE #-} Match	( match )
diff --git a/compiler/ghci/RtClosureInspect.hs b/compiler/ghci/RtClosureInspect.hs
index 269a7bb1d2..8941638663 100644
--- a/compiler/ghci/RtClosureInspect.hs
+++ b/compiler/ghci/RtClosureInspect.hs
@@ -68,6 +68,7 @@ import PrelNames
 import TysWiredIn
 
 import Outputable
+import FastString
 import Panic
 
 #ifndef GHCI_TABLES_NEXT_TO_CODE
diff --git a/compiler/hsSyn/HsBinds.lhs b/compiler/hsSyn/HsBinds.lhs
index 07c631a62c..d1c2234cc0 100644
--- a/compiler/hsSyn/HsBinds.lhs
+++ b/compiler/hsSyn/HsBinds.lhs
@@ -35,6 +35,7 @@ import SrcLoc
 import Util
 import Var
 import Bag
+import FastString
 \end{code}
 
 %************************************************************************
diff --git a/compiler/hsSyn/HsDoc.hs b/compiler/hsSyn/HsDoc.hs
index dc7245d4d3..fd721c00c0 100644
--- a/compiler/hsSyn/HsDoc.hs
+++ b/compiler/hsSyn/HsDoc.hs
@@ -6,8 +6,6 @@ module HsDoc (
   ppr_mbDoc
   ) where
 
--- XXX This define is a bit of a hack, and should be done more nicely
-#define FAST_STRING_NOT_NEEDED 1
 #include "HsVersions.h"
 
 import Outputable
diff --git a/compiler/hsSyn/HsSyn.lhs b/compiler/hsSyn/HsSyn.lhs
index 66f663328a..20e339f1f5 100644
--- a/compiler/hsSyn/HsSyn.lhs
+++ b/compiler/hsSyn/HsSyn.lhs
@@ -46,6 +46,7 @@ import IfaceSyn		( IfaceBinding )
 import Outputable
 import SrcLoc		( Located(..) )
 import Module		( Module, ModuleName )
+import FastString
 \end{code}
 
 All we actually declare here is the top-level structure for a module.
diff --git a/compiler/hsSyn/HsTypes.lhs b/compiler/hsSyn/HsTypes.lhs
index 2b3fc09b14..25d6566f16 100644
--- a/compiler/hsSyn/HsTypes.lhs
+++ b/compiler/hsSyn/HsTypes.lhs
@@ -38,6 +38,7 @@ import BasicTypes
 import SrcLoc
 import StaticFlags
 import Outputable
+import FastString
 \end{code}
 
 
diff --git a/compiler/iface/LoadIface.lhs b/compiler/iface/LoadIface.lhs
index 6211176f87..feb51d1b73 100644
--- a/compiler/iface/LoadIface.lhs
+++ b/compiler/iface/LoadIface.lhs
@@ -58,6 +58,7 @@ import Outputable
 import BinIface
 import Panic
 import Util
+import FastString
 
 import Control.Monad
 import Data.List
diff --git a/compiler/iface/TcIface.lhs b/compiler/iface/TcIface.lhs
index b50ff7fb66..e1a6d2bd40 100644
--- a/compiler/iface/TcIface.lhs
+++ b/compiler/iface/TcIface.lhs
@@ -58,8 +58,9 @@ import Maybes
 import SrcLoc
 import DynFlags
 import Util
-import Control.Monad
+import FastString
 
+import Control.Monad
 import Data.List
 import Data.Maybe
 \end{code}
diff --git a/compiler/main/CmdLineParser.hs b/compiler/main/CmdLineParser.hs
index c7ad66e922..8ec2f6a3ef 100644
--- a/compiler/main/CmdLineParser.hs
+++ b/compiler/main/CmdLineParser.hs
@@ -14,8 +14,6 @@ module CmdLineParser (
         CmdLineP(..), getCmdLineState, putCmdLineState
   ) where
 
--- XXX This define is a bit of a hack, and should be done more nicely
-#define FAST_STRING_NOT_NEEDED 1
 #include "HsVersions.h"
 
 import Util
diff --git a/compiler/main/Constants.lhs b/compiler/main/Constants.lhs
index d26db11b9e..51971728a0 100644
--- a/compiler/main/Constants.lhs
+++ b/compiler/main/Constants.lhs
@@ -13,8 +13,6 @@ import Data.Bits (shiftL)
 -- we want; if we just hope a -I... will get the right one, we could
 -- be in trouble.
 
--- XXX This define is a bit of a hack, and should be done more nicely
-#define FAST_STRING_NOT_NEEDED 1
 #include "HsVersions.h"
 #include "../includes/MachRegs.h"
 #include "../includes/Constants.h"
diff --git a/compiler/main/DriverMkDepend.hs b/compiler/main/DriverMkDepend.hs
index 901b3bb7ce..4155274e31 100644
--- a/compiler/main/DriverMkDepend.hs
+++ b/compiler/main/DriverMkDepend.hs
@@ -35,6 +35,7 @@ import Panic
 import SrcLoc
 import Data.List
 import CmdLineParser
+import FastString
 
 import ErrUtils         ( debugTraceMsg, putMsg )
 
diff --git a/compiler/main/DriverPipeline.hs b/compiler/main/DriverPipeline.hs
index 50b45017c4..59535f040c 100644
--- a/compiler/main/DriverPipeline.hs
+++ b/compiler/main/DriverPipeline.hs
@@ -45,6 +45,7 @@ import Maybes		( expectJust )
 import ParserCoreUtils	( getCoreModuleName )
 import SrcLoc		( unLoc )
 import SrcLoc		( Located(..) )
+import FastString
 
 import Control.Exception as Exception
 import Data.IORef	( readIORef, writeIORef, IORef )
diff --git a/compiler/main/DynFlags.hs b/compiler/main/DynFlags.hs
index 3645e080cf..7fc2c9a01c 100644
--- a/compiler/main/DynFlags.hs
+++ b/compiler/main/DynFlags.hs
@@ -60,8 +60,6 @@ module DynFlags (
     compilerInfo,
   ) where
 
--- XXX This define is a bit of a hack, and should be done more nicely
-#define FAST_STRING_NOT_NEEDED 1
 #include "HsVersions.h"
 
 import Module
diff --git a/compiler/main/ErrUtils.lhs b/compiler/main/ErrUtils.lhs
index 455b3bfe37..9ce02a3d2c 100644
--- a/compiler/main/ErrUtils.lhs
+++ b/compiler/main/ErrUtils.lhs
@@ -28,8 +28,6 @@ module ErrUtils (
 	debugTraceMsg,	
     ) where
 
--- XXX This define is a bit of a hack, and should be done more nicely
-#define FAST_STRING_NOT_NEEDED 1
 #include "HsVersions.h"
 
 import Bag		( Bag, bagToList, isEmptyBag, emptyBag )
diff --git a/compiler/main/GHC.hs b/compiler/main/GHC.hs
index 0caa1cbbf7..bd6eee6a1b 100644
--- a/compiler/main/GHC.hs
+++ b/compiler/main/GHC.hs
@@ -266,6 +266,7 @@ import BasicTypes
 import Maybes		( expectJust, mapCatMaybes )
 import HaddockParse
 import HaddockLex       ( tokenise )
+import FastString
 
 import Control.Concurrent
 import System.Directory ( getModificationTime, doesFileExist,
diff --git a/compiler/main/HscStats.lhs b/compiler/main/HscStats.lhs
index 52e396dcde..e717bfec64 100644
--- a/compiler/main/HscStats.lhs
+++ b/compiler/main/HscStats.lhs
@@ -6,8 +6,6 @@
 \begin{code}
 module HscStats ( ppSourceStats ) where
 
--- XXX This define is a bit of a hack, and should be done more nicely
-#define FAST_STRING_NOT_NEEDED 1
 #include "HsVersions.h"
 
 import HsSyn
diff --git a/compiler/main/HscTypes.lhs b/compiler/main/HscTypes.lhs
index 07c7568497..ec872626d0 100644
--- a/compiler/main/HscTypes.lhs
+++ b/compiler/main/HscTypes.lhs
@@ -112,7 +112,7 @@ import BreakArray
 import SrcLoc		( SrcSpan, Located )
 import LazyUniqFM		( lookupUFM, eltsUFM, emptyUFM )
 import UniqSupply	( UniqSupply )
-import FastString	( FastString )
+import FastString
 import StringBuffer	( StringBuffer )
 
 import System.FilePath
diff --git a/compiler/main/PackageConfig.hs b/compiler/main/PackageConfig.hs
index c070ca2efb..80488ec05f 100644
--- a/compiler/main/PackageConfig.hs
+++ b/compiler/main/PackageConfig.hs
@@ -22,10 +22,6 @@ import Distribution.Package
 import Distribution.Version
 import Distribution.Compat.ReadP ( readP_to_S )
 
--- warning suppression
-_unused :: FS.FastString
-_unused = FSLIT("")
-
 -- -----------------------------------------------------------------------------
 -- Our PackageConfig type is just InstalledPackageInfo from Cabal.  Later we
 -- might need to extend it with some GHC-specific stuff, but for now it's fine.
diff --git a/compiler/main/PprTyThing.hs b/compiler/main/PprTyThing.hs
index e57122b721..0609660285 100644
--- a/compiler/main/PprTyThing.hs
+++ b/compiler/main/PprTyThing.hs
@@ -27,6 +27,7 @@ import TcType
 import Var
 import Name
 import Outputable
+import FastString
 
 -- -----------------------------------------------------------------------------
 -- Pretty-printing entities that we get from the GHC API
diff --git a/compiler/main/StaticFlags.hs b/compiler/main/StaticFlags.hs
index 7200c35dca..a2362d91e5 100644
--- a/compiler/main/StaticFlags.hs
+++ b/compiler/main/StaticFlags.hs
@@ -75,7 +75,7 @@ module StaticFlags (
 
 import CmdLineParser
 import Config
-import FastString	( FastString, mkFastString )
+import FastString
 import Util
 import Maybes		( firstJust )
 import Panic
diff --git a/compiler/main/SysTools.lhs b/compiler/main/SysTools.lhs
index 576c3fc1f1..97a5ea7bf6 100644
--- a/compiler/main/SysTools.lhs
+++ b/compiler/main/SysTools.lhs
@@ -74,7 +74,7 @@ import CString		( CString, peekCString )
 
 import System.Process	( runInteractiveProcess, getProcessExitCode )
 import Control.Concurrent( forkIO, newChan, readChan, writeChan )
-import FastString       ( mkFastString )
+import FastString
 import SrcLoc           ( SrcLoc, mkSrcLoc, noSrcSpan, mkSrcSpan )
 \end{code}
 
diff --git a/compiler/main/TidyPgm.lhs b/compiler/main/TidyPgm.lhs
index ca021222da..64f3498ad4 100644
--- a/compiler/main/TidyPgm.lhs
+++ b/compiler/main/TidyPgm.lhs
@@ -45,9 +45,6 @@ import FastBool hiding ( fastOr )
 import Data.List	( partition )
 import Data.Maybe	( isJust )
 import Data.IORef	( IORef, readIORef, writeIORef )
-
-_dummy :: FS.FastString
-_dummy = FSLIT("")
 \end{code}
 
 
diff --git a/compiler/nativeGen/PositionIndependentCode.hs b/compiler/nativeGen/PositionIndependentCode.hs
index 7d13f114e2..8cd797d84b 100644
--- a/compiler/nativeGen/PositionIndependentCode.hs
+++ b/compiler/nativeGen/PositionIndependentCode.hs
@@ -76,6 +76,7 @@ import qualified Outputable
 
 import Panic            ( panic )
 import DynFlags
+import FastString
 
 
 -- The most important function here is cmmMakeDynamicReference.
diff --git a/compiler/nativeGen/RegAllocLinear.hs b/compiler/nativeGen/RegAllocLinear.hs
index 4b023c5e76..14d7eba5a4 100644
--- a/compiler/nativeGen/RegAllocLinear.hs
+++ b/compiler/nativeGen/RegAllocLinear.hs
@@ -101,6 +101,7 @@ import UniqFM
 import UniqSupply
 import Outputable
 import State
+import FastString
 
 import Data.Maybe
 import Data.List
diff --git a/compiler/nativeGen/RegLiveness.hs b/compiler/nativeGen/RegLiveness.hs
index 9ee98971ba..6bee0c85fc 100644
--- a/compiler/nativeGen/RegLiveness.hs
+++ b/compiler/nativeGen/RegLiveness.hs
@@ -46,6 +46,7 @@ import UniqFM
 import UniqSupply
 import Bag
 import State
+import FastString
 
 import Data.List
 import Data.Maybe
diff --git a/compiler/prelude/ForeignCall.lhs b/compiler/prelude/ForeignCall.lhs
index e97a2415d0..50130785cd 100644
--- a/compiler/prelude/ForeignCall.lhs
+++ b/compiler/prelude/ForeignCall.lhs
@@ -26,7 +26,7 @@ module ForeignCall (
 
 #include "HsVersions.h"
 
-import FastString	( FastString, unpackFS )
+import FastString
 import Char		( isAlphaNum )
 import Binary
 import Outputable
diff --git a/compiler/prelude/TysPrim.lhs b/compiler/prelude/TysPrim.lhs
index 9aa837d3b4..6b02116222 100644
--- a/compiler/prelude/TysPrim.lhs
+++ b/compiler/prelude/TysPrim.lhs
@@ -68,7 +68,7 @@ import SrcLoc
 import Unique		( mkAlphaTyVarUnique, pprUnique )
 import PrelNames
 import StaticFlags
-import FastString	( FastString, mkFastString )
+import FastString
 import Outputable
 
 import Char 		( ord, chr )
diff --git a/compiler/profiling/SCCfinal.lhs b/compiler/profiling/SCCfinal.lhs
index e4d199ccd6..a254a08a38 100644
--- a/compiler/profiling/SCCfinal.lhs
+++ b/compiler/profiling/SCCfinal.lhs
@@ -25,8 +25,6 @@ This is now a sort-of-normal STG-to-STG pass (WDP 94/06), run by stg2stg.
 \begin{code}
 module SCCfinal ( stgMassageForProfiling ) where
 
--- XXX This define is a bit of a hack, and should be done more nicely
-#define FAST_STRING_NOT_NEEDED 1
 #include "HsVersions.h"
 
 import StgSyn
diff --git a/compiler/rename/RnBinds.lhs b/compiler/rename/RnBinds.lhs
index 638e9554a9..e27be3df77 100644
--- a/compiler/rename/RnBinds.lhs
+++ b/compiler/rename/RnBinds.lhs
@@ -60,6 +60,7 @@ import BasicTypes	( RecFlag(..) )
 import Digraph		( SCC(..), stronglyConnComp )
 import Bag
 import Outputable
+import FastString
 import Maybes		( orElse )
 import Util		( filterOut )
 import Monad		( foldM, unless )
diff --git a/compiler/rename/RnNames.lhs b/compiler/rename/RnNames.lhs
index b9e491e461..d01c5b7de2 100644
--- a/compiler/rename/RnNames.lhs
+++ b/compiler/rename/RnNames.lhs
@@ -49,6 +49,7 @@ import ErrUtils
 import BasicTypes	( DeprecTxt, Fixity )
 import DriverPhases	( isHsBoot )
 import Util
+import FastString
 import ListSetOps
 import Data.List        ( partition, concatMap, (\\), delete )
 import IO		( openFile, IOMode(..) )
diff --git a/compiler/rename/RnSource.lhs b/compiler/rename/RnSource.lhs
index 741440ffe2..70c995748c 100644
--- a/compiler/rename/RnSource.lhs
+++ b/compiler/rename/RnSource.lhs
@@ -49,6 +49,7 @@ import NameEnv
 import LazyUniqFM
 import OccName 
 import Outputable
+import FastString
 import SrcLoc		( Located(..), unLoc, noLoc )
 import DynFlags	( DynFlag(..) )
 import Maybe            ( isNothing )
diff --git a/compiler/rename/RnTypes.lhs b/compiler/rename/RnTypes.lhs
index 3de4345458..0e58a59794 100644
--- a/compiler/rename/RnTypes.lhs
+++ b/compiler/rename/RnTypes.lhs
@@ -31,6 +31,7 @@ import NameSet
 import BasicTypes	( compareFixity, funTyFixity, negateFixity, 
 			  Fixity(..), FixityDirection(..) )
 import Outputable
+import FastString
 
 #include "HsVersions.h"
 \end{code}
diff --git a/compiler/simplCore/CSE.lhs b/compiler/simplCore/CSE.lhs
index 93b0b8dd60..38c1f58ee5 100644
--- a/compiler/simplCore/CSE.lhs
+++ b/compiler/simplCore/CSE.lhs
@@ -23,6 +23,7 @@ import StaticFlags	( opt_PprStyle_Debug )
 import BasicTypes	( isAlwaysActive )
 import Util		( lengthExceeds )
 import UniqFM
+import FastString
 
 import Data.List
 \end{code}
diff --git a/compiler/simplCore/FloatOut.lhs b/compiler/simplCore/FloatOut.lhs
index e6e8b7a015..41797746e1 100644
--- a/compiler/simplCore/FloatOut.lhs
+++ b/compiler/simplCore/FloatOut.lhs
@@ -31,6 +31,7 @@ import SetLevels	( Level(..), LevelledExpr, LevelledBind,
 import UniqSupply       ( UniqSupply )
 import List		( partition )
 import Outputable
+import FastString
 \end{code}
 
 	-----------------
diff --git a/compiler/simplCore/OccurAnal.lhs b/compiler/simplCore/OccurAnal.lhs
index 7c7cf89d41..794217f76f 100644
--- a/compiler/simplCore/OccurAnal.lhs
+++ b/compiler/simplCore/OccurAnal.lhs
@@ -15,8 +15,6 @@ module OccurAnal (
         occurAnalysePgm, occurAnalyseExpr
     ) where
 
--- XXX This define is a bit of a hack, and should be done more nicely
-#define FAST_STRING_NOT_NEEDED 1
 #include "HsVersions.h"
 
 import CoreSyn
diff --git a/compiler/simplCore/SimplEnv.lhs b/compiler/simplCore/SimplEnv.lhs
index 462a697da3..699ba7be15 100644
--- a/compiler/simplCore/SimplEnv.lhs
+++ b/compiler/simplCore/SimplEnv.lhs
@@ -66,6 +66,7 @@ import DynFlags
 import Util
 import MonadUtils
 import Outputable
+import FastString
 
 import Data.List
 \end{code}
diff --git a/compiler/simplCore/SimplMonad.lhs b/compiler/simplCore/SimplMonad.lhs
index d914ef3bdc..ea5ce12ba7 100644
--- a/compiler/simplCore/SimplMonad.lhs
+++ b/compiler/simplCore/SimplMonad.lhs
@@ -43,7 +43,7 @@ import StaticFlags	( opt_PprStyle_Debug, opt_HistorySize )
 import Unique		( Unique )
 import Maybes		( expectJust )
 import FiniteMap	( FiniteMap, emptyFM, isEmptyFM, lookupFM, addToFM, plusFM_C, fmToList )
-import FastString	( FastString )
+import FastString
 import Outputable
 import FastTypes
 
diff --git a/compiler/simplCore/SimplUtils.lhs b/compiler/simplCore/SimplUtils.lhs
index 060d346bd3..6d2250550e 100644
--- a/compiler/simplCore/SimplUtils.lhs
+++ b/compiler/simplCore/SimplUtils.lhs
@@ -58,6 +58,7 @@ import BasicTypes
 import Util
 import MonadUtils
 import Outputable
+import FastString
 
 import List( nub )
 \end{code}
diff --git a/compiler/simplCore/Simplify.lhs b/compiler/simplCore/Simplify.lhs
index d41de74fb5..27d2c541dd 100644
--- a/compiler/simplCore/Simplify.lhs
+++ b/compiler/simplCore/Simplify.lhs
@@ -34,6 +34,7 @@ import BasicTypes       ( TopLevelFlag(..), isTopLevel,
 import Maybes           ( orElse )
 import Data.List        ( mapAccumL )
 import Outputable
+import FastString
 \end{code}
 
 
diff --git a/compiler/simplStg/SRT.lhs b/compiler/simplStg/SRT.lhs
index 1a17c06228..989fa4c1f8 100644
--- a/compiler/simplStg/SRT.lhs
+++ b/compiler/simplStg/SRT.lhs
@@ -16,8 +16,6 @@ bindings have no CAF references, and record the fact in their IdInfo.
 
 module SRT( computeSRTs ) where
 
--- XXX This define is a bit of a hack, and should be done more nicely
-#define FAST_STRING_NOT_NEEDED 1
 #include "HsVersions.h"
 
 import StgSyn
diff --git a/compiler/simplStg/SimplStg.lhs b/compiler/simplStg/SimplStg.lhs
index e0d13c6770..e31415b2f5 100644
--- a/compiler/simplStg/SimplStg.lhs
+++ b/compiler/simplStg/SimplStg.lhs
@@ -6,8 +6,6 @@
 \begin{code}
 module SimplStg ( stg2stg ) where
 
--- XXX This define is a bit of a hack, and should be done more nicely
-#define FAST_STRING_NOT_NEEDED 1
 #include "HsVersions.h"
 
 import StgSyn
diff --git a/compiler/simplStg/StgStats.lhs b/compiler/simplStg/StgStats.lhs
index bca2bbb13b..25c988d52b 100644
--- a/compiler/simplStg/StgStats.lhs
+++ b/compiler/simplStg/StgStats.lhs
@@ -30,8 +30,6 @@ The program gather statistics about
 
 module StgStats ( showStgStats ) where
 
--- XXX This define is a bit of a hack, and should be done more nicely
-#define FAST_STRING_NOT_NEEDED 1
 #include "HsVersions.h"
 
 import StgSyn
diff --git a/compiler/stgSyn/CoreToStg.lhs b/compiler/stgSyn/CoreToStg.lhs
index d03412ad3d..dbb785bed4 100644
--- a/compiler/stgSyn/CoreToStg.lhs
+++ b/compiler/stgSyn/CoreToStg.lhs
@@ -39,6 +39,7 @@ import StaticFlags	( opt_RuntimeTypes )
 import Module
 import Outputable
 import MonadUtils
+import FastString
 import Util
 \end{code}
 
diff --git a/compiler/stgSyn/StgLint.lhs b/compiler/stgSyn/StgLint.lhs
index 9dc83cd863..23e8f3b39a 100644
--- a/compiler/stgSyn/StgLint.lhs
+++ b/compiler/stgSyn/StgLint.lhs
@@ -34,6 +34,7 @@ import TyCon            ( isAlgTyCon, isNewTyCon, tyConDataCons )
 import Util             ( zipEqual, equalLength )
 import SrcLoc           ( srcLocSpan )
 import Outputable
+import FastString
 import Control.Monad
 \end{code}
 
diff --git a/compiler/stgSyn/StgSyn.lhs b/compiler/stgSyn/StgSyn.lhs
index 893358b8cd..42bcabb9c2 100644
--- a/compiler/stgSyn/StgSyn.lhs
+++ b/compiler/stgSyn/StgSyn.lhs
@@ -67,6 +67,7 @@ import Unique		( Unique )
 import Bitmap
 import StaticFlags	( opt_SccProfilingOn )
 import Module
+import FastString
 \end{code}
 
 %************************************************************************
diff --git a/compiler/stranal/WwLib.lhs b/compiler/stranal/WwLib.lhs
index 5f63a481bf..4254d35de8 100644
--- a/compiler/stranal/WwLib.lhs
+++ b/compiler/stranal/WwLib.lhs
@@ -28,6 +28,7 @@ import UniqSupply
 import Unique
 import Util		( zipWithEqual, notNull )
 import Outputable
+import FastString
 import List		( zipWith4 )
 \end{code}
 
diff --git a/compiler/typecheck/FamInst.lhs b/compiler/typecheck/FamInst.lhs
index ca5a7e9084..224a9601b8 100644
--- a/compiler/typecheck/FamInst.lhs
+++ b/compiler/typecheck/FamInst.lhs
@@ -27,6 +27,7 @@ import SrcLoc
 import Outputable
 import LazyUniqFM
 import FiniteMap
+import FastString
 
 import Maybe
 import Monad
diff --git a/compiler/typecheck/Inst.lhs b/compiler/typecheck/Inst.lhs
index d507bddb1b..91e409fe28 100644
--- a/compiler/typecheck/Inst.lhs
+++ b/compiler/typecheck/Inst.lhs
@@ -60,7 +60,7 @@ module Inst (
 import {-# SOURCE #-}	TcExpr( tcPolyExpr )
 import {-# SOURCE #-}	TcUnify( boxyUnify, unifyType )
 
-import FastString(FastString)
+import FastString
 import HsSyn
 import TcHsSyn
 import TcRnMonad
diff --git a/compiler/typecheck/TcArrows.lhs b/compiler/typecheck/TcArrows.lhs
index 90a5e885e3..11daed77da 100644
--- a/compiler/typecheck/TcArrows.lhs
+++ b/compiler/typecheck/TcArrows.lhs
@@ -40,6 +40,7 @@ import Type
 
 import SrcLoc
 import Outputable
+import FastString
 import Util
 
 import Control.Monad
diff --git a/compiler/typecheck/TcBinds.lhs b/compiler/typecheck/TcBinds.lhs
index e3bd6575fd..d9f55874c0 100644
--- a/compiler/typecheck/TcBinds.lhs
+++ b/compiler/typecheck/TcBinds.lhs
@@ -56,6 +56,7 @@ import List
 import Util
 import BasicTypes
 import Outputable
+import FastString
 
 import Control.Monad
 \end{code}
diff --git a/compiler/typecheck/TcDefaults.lhs b/compiler/typecheck/TcDefaults.lhs
index 9da5d96fb5..ad5e9b86a6 100644
--- a/compiler/typecheck/TcDefaults.lhs
+++ b/compiler/typecheck/TcDefaults.lhs
@@ -29,6 +29,7 @@ import DynFlags
 import SrcLoc
 import Maybe
 import Outputable
+import FastString
 \end{code}
 
 \begin{code}
diff --git a/compiler/typecheck/TcDeriv.lhs b/compiler/typecheck/TcDeriv.lhs
index 7422c6fa99..2edd836105 100644
--- a/compiler/typecheck/TcDeriv.lhs
+++ b/compiler/typecheck/TcDeriv.lhs
@@ -46,6 +46,7 @@ import SrcLoc
 import Util
 import ListSetOps
 import Outputable
+import FastString
 import Bag
 \end{code}
 
diff --git a/compiler/typecheck/TcEnv.lhs b/compiler/typecheck/TcEnv.lhs
index ad45c7ca4c..aa27a43c88 100644
--- a/compiler/typecheck/TcEnv.lhs
+++ b/compiler/typecheck/TcEnv.lhs
@@ -81,6 +81,7 @@ import HscTypes
 import SrcLoc
 import Outputable
 import Maybes
+import FastString
 \end{code}
 
 
diff --git a/compiler/typecheck/TcForeign.lhs b/compiler/typecheck/TcForeign.lhs
index dc6220661a..0353f1f43d 100644
--- a/compiler/typecheck/TcForeign.lhs
+++ b/compiler/typecheck/TcForeign.lhs
@@ -49,6 +49,7 @@ import Outputable
 import SrcLoc
 import Bag
 import Unique
+import FastString
 \end{code}
 
 \begin{code}
diff --git a/compiler/typecheck/TcGadt.lhs b/compiler/typecheck/TcGadt.lhs
index 48b2b0623c..e45d6bd53a 100644
--- a/compiler/typecheck/TcGadt.lhs
+++ b/compiler/typecheck/TcGadt.lhs
@@ -41,6 +41,7 @@ import Outputable
 import TcType
 import Unique
 import UniqFM
+import FastString
 \end{code}
 
 
diff --git a/compiler/typecheck/TcHsSyn.lhs b/compiler/typecheck/TcHsSyn.lhs
index 7bb1d5e38d..7afd9e8501 100644
--- a/compiler/typecheck/TcHsSyn.lhs
+++ b/compiler/typecheck/TcHsSyn.lhs
@@ -57,6 +57,7 @@ import SrcLoc
 import Util
 import Bag
 import Outputable
+import FastString
 \end{code}
 
 \begin{code}
diff --git a/compiler/typecheck/TcHsType.lhs b/compiler/typecheck/TcHsType.lhs
index 66102a64df..08f4f7f718 100644
--- a/compiler/typecheck/TcHsType.lhs
+++ b/compiler/typecheck/TcHsType.lhs
@@ -53,6 +53,7 @@ import BasicTypes
 import SrcLoc
 import UniqSupply
 import Outputable
+import FastString
 
 import Control.Monad
 \end{code}
diff --git a/compiler/typecheck/TcMType.lhs b/compiler/typecheck/TcMType.lhs
index 30917eff83..fc434d897f 100644
--- a/compiler/typecheck/TcMType.lhs
+++ b/compiler/typecheck/TcMType.lhs
@@ -88,6 +88,7 @@ import ListSetOps
 import UniqSupply
 import SrcLoc
 import Outputable
+import FastString
 
 import Control.Monad	( when, unless )
 import Data.List	( (\\) )
diff --git a/compiler/typecheck/TcMatches.lhs b/compiler/typecheck/TcMatches.lhs
index b7262d6bf3..5826eb9f1f 100644
--- a/compiler/typecheck/TcMatches.lhs
+++ b/compiler/typecheck/TcMatches.lhs
@@ -42,6 +42,7 @@ import TysPrim
 import Outputable
 import Util
 import SrcLoc
+import FastString
 
 import Control.Monad
 \end{code}
diff --git a/compiler/typecheck/TcRnTypes.lhs b/compiler/typecheck/TcRnTypes.lhs
index 98bb936b50..a33faa1691 100644
--- a/compiler/typecheck/TcRnTypes.lhs
+++ b/compiler/typecheck/TcRnTypes.lhs
@@ -74,6 +74,7 @@ import Bag
 import Outputable
 import ListSetOps
 import FiniteMap
+import FastString
 
 import Data.Maybe
 import Data.List
diff --git a/compiler/typecheck/TcRules.lhs b/compiler/typecheck/TcRules.lhs
index a0774fed62..50ad098e1e 100644
--- a/compiler/typecheck/TcRules.lhs
+++ b/compiler/typecheck/TcRules.lhs
@@ -30,6 +30,7 @@ import Id
 import Name
 import SrcLoc
 import Outputable
+import FastString
 \end{code}
 
 \begin{code}
diff --git a/compiler/typecheck/TcSimplify.lhs b/compiler/typecheck/TcSimplify.lhs
index 63529c12c1..a5ce732331 100644
--- a/compiler/typecheck/TcSimplify.lhs
+++ b/compiler/typecheck/TcSimplify.lhs
@@ -64,6 +64,7 @@ import Util
 import UniqSet
 import SrcLoc
 import DynFlags
+import FastString
 
 import Control.Monad
 import Data.List
diff --git a/compiler/typecheck/TcTyClsDecls.lhs b/compiler/typecheck/TcTyClsDecls.lhs
index 054f58b4dc..12fb28d7ae 100644
--- a/compiler/typecheck/TcTyClsDecls.lhs
+++ b/compiler/typecheck/TcTyClsDecls.lhs
@@ -51,6 +51,7 @@ import SrcLoc
 import ListSetOps
 import Digraph
 import DynFlags
+import FastString
 
 import Data.List
 import Control.Monad    ( mplus )
diff --git a/compiler/typecheck/TcTyFuns.lhs b/compiler/typecheck/TcTyFuns.lhs
index 36ff1bbb3e..625d4cdd72 100644
--- a/compiler/typecheck/TcTyFuns.lhs
+++ b/compiler/typecheck/TcTyFuns.lhs
@@ -35,6 +35,7 @@ import Bag
 import Outputable
 import SrcLoc	( Located(..) )
 import Maybes
+import FastString
 
 -- standard
 import Data.List
diff --git a/compiler/typecheck/TcType.lhs b/compiler/typecheck/TcType.lhs
index c263660f4a..95d8deb964 100644
--- a/compiler/typecheck/TcType.lhs
+++ b/compiler/typecheck/TcType.lhs
@@ -165,6 +165,7 @@ import Util
 import Maybes
 import ListSetOps
 import Outputable
+import FastString
 
 import Data.List
 import Data.IORef
diff --git a/compiler/typecheck/TcUnify.lhs b/compiler/typecheck/TcUnify.lhs
index 4aa9b3d3c4..d7399f5cd3 100644
--- a/compiler/typecheck/TcUnify.lhs
+++ b/compiler/typecheck/TcUnify.lhs
@@ -60,6 +60,7 @@ import BasicTypes
 import Util
 import Outputable
 import Unique
+import FastString
 
 import Control.Monad
 \end{code}
diff --git a/compiler/types/Class.lhs b/compiler/types/Class.lhs
index 051bef165c..2f946d8592 100644
--- a/compiler/types/Class.lhs
+++ b/compiler/types/Class.lhs
@@ -27,6 +27,7 @@ import Name
 import BasicTypes
 import Unique
 import Outputable
+import FastString
 \end{code}
 
 %************************************************************************
diff --git a/compiler/types/Coercion.lhs b/compiler/types/Coercion.lhs
index 9ebd00e760..674e2a70bd 100644
--- a/compiler/types/Coercion.lhs
+++ b/compiler/types/Coercion.lhs
@@ -70,7 +70,7 @@ import Util
 import Unique
 import BasicTypes
 import Outputable
-
+import FastString
 
 type Coercion     = Type
 type CoercionKind = Kind	-- A CoercionKind is always of form (ty1 :=: ty2)
@@ -438,7 +438,7 @@ unsafeCoercionTyCon
 --------------------------------------
 -- ...and their names
 
-mkCoConName :: FS.FastString -> Unique -> TyCon -> Name
+mkCoConName :: FastString -> Unique -> TyCon -> Name
 mkCoConName occ key coCon = mkWiredInName gHC_PRIM (mkOccNameFS tcName occ)
                             key (ATyCon coCon) BuiltInSyntax
 
diff --git a/compiler/types/FamInstEnv.lhs b/compiler/types/FamInstEnv.lhs
index 3bfe55d1f0..396c844047 100644
--- a/compiler/types/FamInstEnv.lhs
+++ b/compiler/types/FamInstEnv.lhs
@@ -37,6 +37,7 @@ import UniqFM
 import Outputable
 import Maybes
 import Util
+import FastString
 
 import Maybe
 \end{code}
diff --git a/compiler/types/FunDeps.lhs b/compiler/types/FunDeps.lhs
index ac5c0a0b1e..26c0d68e92 100644
--- a/compiler/types/FunDeps.lhs
+++ b/compiler/types/FunDeps.lhs
@@ -27,6 +27,8 @@ import VarSet
 import VarEnv
 import Outputable
 import Util
+import FastString
+
 import Data.Maybe	( isJust )
 \end{code}
 
diff --git a/compiler/types/InstEnv.lhs b/compiler/types/InstEnv.lhs
index 8fd3d83244..68a86aab25 100644
--- a/compiler/types/InstEnv.lhs
+++ b/compiler/types/InstEnv.lhs
@@ -33,6 +33,7 @@ import Outputable
 import BasicTypes
 import UniqFM
 import Id
+import FastString
 
 import Data.Maybe	( isJust, isNothing )
 \end{code}
diff --git a/compiler/types/Type.lhs b/compiler/types/Type.lhs
index d5c00e8070..686bba849f 100644
--- a/compiler/types/Type.lhs
+++ b/compiler/types/Type.lhs
@@ -130,6 +130,7 @@ import TyCon
 import StaticFlags
 import Util
 import Outputable
+import FastString
 
 import Data.List
 import Data.Maybe	( isJust )
diff --git a/compiler/types/Unify.lhs b/compiler/types/Unify.lhs
index 63c64f07a1..63089b603e 100644
--- a/compiler/types/Unify.lhs
+++ b/compiler/types/Unify.lhs
@@ -13,8 +13,6 @@ module Unify (
 	dataConCannotMatch
    ) where
 
--- XXX This define is a bit of a hack, and should be done more nicely
-#define FAST_STRING_NOT_NEEDED 1
 #include "HsVersions.h"
 
 import Var
diff --git a/compiler/utils/Digraph.lhs b/compiler/utils/Digraph.lhs
index c36e7058fc..6d1d8d4639 100644
--- a/compiler/utils/Digraph.lhs
+++ b/compiler/utils/Digraph.lhs
@@ -24,8 +24,6 @@ module Digraph(
         bcc
     ) where
 
--- XXX This define is a bit of a hack, and should be done more nicely
-#define FAST_STRING_NOT_NEEDED 1
 #include "HsVersions.h"
 
 ------------------------------------------------------------------------------
diff --git a/compiler/utils/Encoding.hs b/compiler/utils/Encoding.hs
index 2943768d56..f2659e6a9a 100644
--- a/compiler/utils/Encoding.hs
+++ b/compiler/utils/Encoding.hs
@@ -23,7 +23,6 @@ module Encoding (
 	zDecodeString
   ) where
 
-#define COMPILING_FAST_STRING
 #include "HsVersions.h"
 import Foreign
 import Data.Char	( ord, chr, isDigit, digitToInt, intToDigit,
diff --git a/compiler/utils/FastFunctions.lhs b/compiler/utils/FastFunctions.lhs
index 5d8ff23dbd..aca5344bc8 100644
--- a/compiler/utils/FastFunctions.lhs
+++ b/compiler/utils/FastFunctions.lhs
@@ -12,7 +12,6 @@ module FastFunctions (
     global, Global
   ) where
 
-#define COMPILING_FAST_STRING
 #include "HsVersions.h"
 
 import FastTypes
diff --git a/compiler/utils/FastString.lhs b/compiler/utils/FastString.lhs
index 2448f1686d..4417c0850f 100644
--- a/compiler/utils/FastString.lhs
+++ b/compiler/utils/FastString.lhs
@@ -71,9 +71,6 @@ module FastString
         ptrStrLength
        ) where
 
--- This #define suppresses the "import FastString" that
--- HsVersions otherwise produces
-#define COMPILING_FAST_STRING
 #include "HsVersions.h"
 
 import Encoding
diff --git a/compiler/utils/FastTypes.lhs b/compiler/utils/FastTypes.lhs
index 71a317b1c9..a69ab25671 100644
--- a/compiler/utils/FastTypes.lhs
+++ b/compiler/utils/FastTypes.lhs
@@ -39,7 +39,6 @@ module FastTypes (
     FastPtr, pBox, pUnbox, castFastPtr
   ) where
 
-#define COMPILING_FAST_STRING
 #include "HsVersions.h"
 
 #if defined(__GLASGOW_HASKELL__)
diff --git a/compiler/utils/Interval.hs b/compiler/utils/Interval.hs
index 8d96b19c7d..03545ebc40 100644
--- a/compiler/utils/Interval.hs
+++ b/compiler/utils/Interval.hs
@@ -111,6 +111,6 @@ rev_app :: [a] -> [a] -> [a]
 rev_app [] xs = xs
 rev_app (y:ys) xs = rev_app ys (y:xs)
 
-          
-_unused :: FS.FastString
+_unused :: ()
 _unused = undefined i_min i_lim overlaps contains
+
diff --git a/compiler/utils/Panic.lhs b/compiler/utils/Panic.lhs
index ffd3b6751d..f79ffce783 100644
--- a/compiler/utils/Panic.lhs
+++ b/compiler/utils/Panic.lhs
@@ -22,8 +22,6 @@ module Panic
      installSignalHandlers, interruptTargetThread
    ) where
 
--- XXX This define is a bit of a hack, and should be done more nicely
-#define FAST_STRING_NOT_NEEDED 1
 #include "HsVersions.h"
 
 import Config
diff --git a/compiler/utils/UniqFM.lhs b/compiler/utils/UniqFM.lhs
index 862ca589d8..4081017f87 100644
--- a/compiler/utils/UniqFM.lhs
+++ b/compiler/utils/UniqFM.lhs
@@ -839,7 +839,3 @@ use_snd :: a -> b -> b
 use_snd _ b = b
 \end{code}
 
-\begin{code}
-_unused :: FS.FastString
-_unused = undefined
-\end{code}
diff --git a/compiler/utils/Util.lhs b/compiler/utils/Util.lhs
index 9537ae1f37..1d11b90a55 100644
--- a/compiler/utils/Util.lhs
+++ b/compiler/utils/Util.lhs
@@ -74,8 +74,6 @@ module Util (
         Direction(..), reslash,
     ) where
 
--- XXX This define is a bit of a hack, and should be done more nicely
-#define FAST_STRING_NOT_NEEDED 1
 #include "HsVersions.h"
 
 import Panic
diff --git a/compiler/vectorise/VectCore.hs b/compiler/vectorise/VectCore.hs
index 34ffdb7cae..de832793f6 100644
--- a/compiler/vectorise/VectCore.hs
+++ b/compiler/vectorise/VectCore.hs
@@ -11,8 +11,6 @@ module VectCore (
   vCaseDEFAULT, vCaseProd
 ) where
 
--- XXX This define is a bit of a hack, and should be done more nicely
-#define FAST_STRING_NOT_NEEDED 1
 #include "HsVersions.h"
 
 import CoreSyn
diff --git a/compiler/vectorise/VectType.hs b/compiler/vectorise/VectType.hs
index 86dcaf236b..cfcea389bb 100644
--- a/compiler/vectorise/VectType.hs
+++ b/compiler/vectorise/VectType.hs
@@ -45,6 +45,7 @@ import Util              ( singleton )
 import Digraph           ( SCC(..), stronglyConnComp )
 
 import Outputable
+import FastString
 
 import Control.Monad  ( liftM, liftM2, zipWithM, zipWithM_, mapAndUnzipM )
 import Data.List      ( inits, tails, zipWith4, zipWith5 )