Use -fwarn-tabs when validating

We only use it for "compiler" sources, i.e. not for libraries.
Many modules have a -fno-warn-tabs kludge for now.

compiler/basicTypes/Avail.hs

@@ -2,6 +2,13 @@
 -- (c) The University of Glasgow
 --
 
+{-# OPTIONS -fno-warn-tabs #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and
+-- detab the module (please do the detabbing in a separate patch). See
+--     http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#TabsvsSpaces
+-- for details
+
 module Avail (
     Avails,
     AvailInfo(..),

compiler/basicTypes/BasicTypes.lhs

@@ -16,6 +16,13 @@ types that
 \begin{code}
 {-# LANGUAGE DeriveDataTypeable #-}
 
+{-# OPTIONS -fno-warn-tabs #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and
+-- detab the module (please do the detabbing in a separate patch). See
+--     http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#TabsvsSpaces
+-- for details
+
 module BasicTypes(
 	Version, bumpVersion, initialVersion,
 

compiler/basicTypes/DataCon.lhs

@@ -5,6 +5,13 @@
 \section[DataCon]{@DataCon@: Data Constructors}
 
 \begin{code}
+{-# OPTIONS -fno-warn-tabs #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and
+-- detab the module (please do the detabbing in a separate patch). See
+--     http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#TabsvsSpaces
+-- for details
+
 module DataCon (
         -- * Main data types
 	DataCon, DataConIds(..),

compiler/basicTypes/Demand.lhs

@@ -5,6 +5,13 @@
 \section[Demand]{@Demand@: the amount of demand on a value}
 
 \begin{code}
+{-# OPTIONS -fno-warn-tabs #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and
+-- detab the module (please do the detabbing in a separate patch). See
+--     http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#TabsvsSpaces
+-- for details
+
 module Demand(
 	Demand(..), 
 	topDmd, lazyDmd, seqDmd, evalDmd, errDmd, isStrictDmd, 

compiler/basicTypes/Id.lhs

@@ -21,6 +21,14 @@
 --   be global or local, see "Var#globalvslocal"
 --
 -- * 'Var.Var': see "Var#name_types"
+
+{-# OPTIONS -fno-warn-tabs #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and
+-- detab the module (please do the detabbing in a separate patch). See
+--     http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#TabsvsSpaces
+-- for details
+
 module Id (
         -- * The main types
 	Var, Id, isId,

compiler/basicTypes/IdInfo.lhs

@@ -8,6 +8,13 @@
 Haskell. [WDP 94/11])
 
 \begin{code}
+{-# OPTIONS -fno-warn-tabs #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and
+-- detab the module (please do the detabbing in a separate patch). See
+--     http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#TabsvsSpaces
+-- for details
+
 module IdInfo (
         -- * The IdDetails type
 	IdDetails(..), pprIdDetails, coVarDetails,

compiler/basicTypes/Literal.lhs

@@ -7,6 +7,13 @@
 \begin{code}
 {-# LANGUAGE DeriveDataTypeable #-}
 
+{-# OPTIONS -fno-warn-tabs #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and
+-- detab the module (please do the detabbing in a separate patch). See
+--     http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#TabsvsSpaces
+-- for details
+
 module Literal
         (
         -- * Main data type

compiler/basicTypes/MkId.lhs

@@ -12,6 +12,13 @@ have a standard form, namely:
 - primitive operations
 
 \begin{code}
+{-# OPTIONS -fno-warn-tabs #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and
+-- detab the module (please do the detabbing in a separate patch). See
+--     http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#TabsvsSpaces
+-- for details
+
 module MkId (
         mkDictFunId, mkDictFunTy, mkDictSelId,
 

compiler/basicTypes/Module.lhs

@@ -9,6 +9,13 @@ These are Uniquable, hence we can build Maps with Modules as
 the keys.
 
 \begin{code}
+{-# OPTIONS -fno-warn-tabs #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and
+-- detab the module (please do the detabbing in a separate patch). See
+--     http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#TabsvsSpaces
+-- for details
+
 module Module 
     (
         -- * The ModuleName type

compiler/basicTypes/Name.lhs

@@ -31,6 +31,13 @@
 --  * Internal, if they name things in the module being compiled. Some internal
 --    Names are system names, if they are names manufactured by the compiler
 
+{-# OPTIONS -fno-warn-tabs #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and
+-- detab the module (please do the detabbing in a separate patch). See
+--     http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#TabsvsSpaces
+-- for details
+
 module Name (
 	-- * The main types
 	Name,					-- Abstract

compiler/basicTypes/NameEnv.lhs

@@ -5,6 +5,13 @@
 \section[NameEnv]{@NameEnv@: name environments}
 
 \begin{code}
+{-# OPTIONS -fno-warn-tabs #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and
+-- detab the module (please do the detabbing in a separate patch). See
+--     http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#TabsvsSpaces
+-- for details
+
 module NameEnv (
 	-- * Var, Id and TyVar environments (maps) 
 	NameEnv, 

compiler/basicTypes/NameSet.lhs

@@ -4,6 +4,13 @@
 %
 
 \begin{code}
+{-# OPTIONS -fno-warn-tabs #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and
+-- detab the module (please do the detabbing in a separate patch). See
+--     http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#TabsvsSpaces
+-- for details
+
 module NameSet (
 	-- * Names set type
 	NameSet,

compiler/basicTypes/OccName.lhs

@@ -19,6 +19,14 @@
 -- * 'Id.Id': see "Id#name_types"
 --
 -- * 'Var.Var': see "Var#name_types"
+
+{-# OPTIONS -fno-warn-tabs #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and
+-- detab the module (please do the detabbing in a separate patch). See
+--     http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#TabsvsSpaces
+-- for details
+
 module OccName (
 	-- * The 'NameSpace' type
 	NameSpace, -- Abstract

compiler/basicTypes/RdrName.lhs

@@ -22,6 +22,14 @@
 -- * 'Id.Id': see "Id#name_types"
 --
 -- * 'Var.Var': see "Var#name_types"
+
+{-# OPTIONS -fno-warn-tabs #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and
+-- detab the module (please do the detabbing in a separate patch). See
+--     http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#TabsvsSpaces
+-- for details
+
 module RdrName (
         -- * The main type
 	RdrName(..),	-- Constructors exported only to BinIface

compiler/basicTypes/SrcLoc.lhs

@@ -8,6 +8,13 @@
    -- When the earliest compiler we want to boostrap with is
    -- GHC 7.2, we can make RealSrcLoc properly abstract
 
+{-# OPTIONS -fno-warn-tabs #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and
+-- detab the module (please do the detabbing in a separate patch). See
+--     http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#TabsvsSpaces
+-- for details
+
 
 -- | This module contains types that relate to the positions of things
 -- in source files, and allow tagging of those things with locations

compiler/basicTypes/Unique.lhs

@@ -17,6 +17,14 @@ Haskell).
 
 \begin{code}
 {-# LANGUAGE BangPatterns #-}
+
+{-# OPTIONS -fno-warn-tabs #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and
+-- detab the module (please do the detabbing in a separate patch). See
+--     http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#TabsvsSpaces
+-- for details
+
 module Unique (
         -- * Main data types
 	Unique, Uniquable(..), 

compiler/basicTypes/Var.lhs

@@ -5,6 +5,13 @@
 \section{@Vars@: Variables}
 
 \begin{code}
+{-# OPTIONS -fno-warn-tabs #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and
+-- detab the module (please do the detabbing in a separate patch). See
+--     http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#TabsvsSpaces
+-- for details
+
 -- |
 -- #name_types#
 -- GHC uses several kinds of name internally:

compiler/basicTypes/VarEnv.lhs

@@ -4,6 +4,13 @@
 %
 
 \begin{code}
+{-# OPTIONS -fno-warn-tabs #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and
+-- detab the module (please do the detabbing in a separate patch). See
+--     http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#TabsvsSpaces
+-- for details
+
 module VarEnv (
         -- * Var, Id and TyVar environments (maps)
 	VarEnv, IdEnv, TyVarEnv, CoVarEnv,

compiler/basicTypes/VarSet.lhs

@@ -4,6 +4,13 @@
 %
 
 \begin{code}
+{-# OPTIONS -fno-warn-tabs #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and
+-- detab the module (please do the detabbing in a separate patch). See
+--     http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#TabsvsSpaces
+-- for details
+
 module VarSet (
         -- * Var, Id and TyVar set types
 	VarSet, IdSet, TyVarSet, CoVarSet,

compiler/cmm/Bitmap.hs

@@ -6,6 +6,13 @@
 -- places in generated code (stack frame liveness masks, function
 -- argument liveness masks, SRT bitmaps).
 
+{-# OPTIONS -fno-warn-tabs #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and
+-- detab the module (please do the detabbing in a separate patch). See
+--     http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#TabsvsSpaces
+-- for details
+
 module Bitmap ( 
 	Bitmap, mkBitmap,
 	intsToBitmap, intsToReverseBitmap,