[project @ 2000-05-25 12:41:14 by simonpj]

~~~~~~~~~~~~
		Apr/May 2000
		~~~~~~~~~~~~

This is a pretty big commit!  It adds stuff I've been working on
over the last month or so.  DO NOT MERGE IT WITH 4.07!

Interface file formats have changed a little; you'll need
to make clean before remaking.

						Simon PJ

Recompilation checking
~~~~~~~~~~~~~~~~~~~~~~
Substantial improvement in recompilation checking.  The version management
is now entirely internal to GHC.  ghc-iface.lprl is dead!

The trick is to generate the new interface file in two steps:
  - first convert Types etc to HsTypes etc, and thereby
	build a new ParsedIface
  - then compare against the parsed (but not renamed) version of the old
	interface file
Doing this meant adding code to convert *to* HsSyn things, and to
compare HsSyn things for equality.  That is the main tedious bit.

Another improvement is that we now track version info for
fixities and rules, which was missing before.


Interface file reading
~~~~~~~~~~~~~~~~~~~~~~
Make interface files reading more robust.
  * If the old interface file is unreadable, don't fail. [bug fix]

  * If the old interface file mentions interfaces
    that are unreadable, don't fail. [bug fix]

  * When we can't find the interface file,
    print the directories we are looking in.  [feature]


Type signatures
~~~~~~~~~~~~~~~
  * New flag -ddump-types to print type signatures


Type pruning
~~~~~~~~~~~~
When importing
	data T = T1 A | T2 B | T3 C
it seems excessive to import the types A, B, C as well, unless
the constructors T1, T2 etc are used.  A,B,C might be more types,
and importing them may mean reading more interfaces, and so on.
 So the idea is that the renamer will just import the decl
	data T
unless one of the constructors is used.  This turns out to be quite
easy to implement.  The downside is that we must make sure the
constructors are always available if they are really needed, so
I regard this as an experimental feature.


Elimininate ThinAir names
~~~~~~~~~~~~~~~~~~~~~~~~~
Eliminate ThinAir.lhs and all its works.  It was always a hack, and now
the desugarer carries around an environment I think we can nuke ThinAir
altogether.

As part of this, I had to move all the Prelude RdrName defns from PrelInfo
to PrelMods --- so I renamed PrelMods as PrelNames.

I also had to move the builtinRules so that they are injected by the renamer
(rather than appearing out of the blue in SimplCore).  This is if anything simpler.

Miscellaneous
~~~~~~~~~~~~~
* Tidy up the data types involved in Rules

* Eliminate RnEnv.better_provenance; use Name.hasBetterProv instead

* Add Unique.hasKey :: Uniquable a => a -> Unique -> Bool
  It's useful in a lot of places

* Fix a bug in interface file parsing for __U[!]

3 files changed, 9 insertions, 7 deletions

diff --git a/ghc/compiler/codeGen/CgCase.lhs b/ghc/compiler/codeGen/CgCase.lhs
index b9c3149194..d64755b4b8 100644
--- a/ghc/compiler/codeGen/CgCase.lhs
+++ b/ghc/compiler/codeGen/CgCase.lhs
@@ -1,7 +1,7 @@
 %
 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
 %
-% $Id: CgCase.lhs,v 1.41 2000/04/13 20:41:30 panne Exp $
+% $Id: CgCase.lhs,v 1.42 2000/05/25 12:41:15 simonpj Exp $
 %
 %********************************************************
 %*							*
@@ -59,7 +59,7 @@ import PrimRep		( getPrimRepSize, retPrimRepSize, PrimRep(..)
 			)
 import TyCon		( TyCon, isEnumerationTyCon, isUnboxedTupleTyCon,
 			  isNewTyCon, isAlgTyCon, isFunTyCon, isPrimTyCon,
-			  tyConDataCons, tyConFamilySize )
+			)
 import Type		( Type, typePrimRep, splitAlgTyConApp, 
 			  splitTyConApp_maybe, repType )
 import PprType		( {- instance Outputable Type -} )
diff --git a/ghc/compiler/codeGen/CgRetConv.lhs b/ghc/compiler/codeGen/CgRetConv.lhs
index f02b4d6590..e292ea1d9f 100644
--- a/ghc/compiler/codeGen/CgRetConv.lhs
+++ b/ghc/compiler/codeGen/CgRetConv.lhs
@@ -1,7 +1,7 @@
 %
 % (c) The GRASP Project, Glasgow University, 1992-1998
 %
-% $Id: CgRetConv.lhs,v 1.21 2000/04/05 16:25:51 simonpj Exp $
+% $Id: CgRetConv.lhs,v 1.22 2000/05/25 12:41:15 simonpj Exp $
 %
 \section[CgRetConv]{Return conventions for the code generator}
 
@@ -30,7 +30,7 @@ import Maybes		( catMaybes )
 import DataCon		( DataCon )
 import PrimOp		( PrimOp{-instance Outputable-} )
 import PrimRep		( isFloatingRep, PrimRep(..), is64BitRep )
-import TyCon		( TyCon, tyConDataCons, tyConFamilySize )
+import TyCon		( TyCon, tyConFamilySize )
 import Type		( Type, typePrimRep, isUnLiftedType )
 import Util		( isn'tIn )
 
diff --git a/ghc/compiler/codeGen/ClosureInfo.lhs b/ghc/compiler/codeGen/ClosureInfo.lhs
index d107e7eb61..302dbc4438 100644
--- a/ghc/compiler/codeGen/ClosureInfo.lhs
+++ b/ghc/compiler/codeGen/ClosureInfo.lhs
@@ -1,7 +1,7 @@
 %
 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
 %
-% $Id: ClosureInfo.lhs,v 1.41 2000/04/05 15:17:38 simonmar Exp $
+% $Id: ClosureInfo.lhs,v 1.42 2000/05/25 12:41:15 simonpj Exp $
 %
 \section[ClosureInfo]{Data structures which describe closures}
 
@@ -81,8 +81,9 @@ import CmdLineOpts	( opt_SccProfilingOn, opt_OmitBlackHoling,
 			  opt_SMP )
 import Id		( Id, idType, idArityInfo )
 import DataCon		( DataCon, dataConTag, fIRST_TAG, dataConTyCon,
-			  isNullaryDataCon, isTupleCon, dataConName
+			  isNullaryDataCon, dataConName
 			)
+import TyCon		( isBoxedTupleTyCon )
 import IdInfo		( ArityInfo(..) )
 import Name		( Name, isExternallyVisibleName, nameUnique, 
 			  getOccName )
@@ -238,7 +239,8 @@ mkConLFInfo :: DataCon -> LambdaFormInfo
 
 mkConLFInfo con
   = -- the isNullaryDataCon will do this: ASSERT(isDataCon con)
-    (if isTupleCon con then LFTuple else LFCon) con (isNullaryDataCon con)
+    (if isBoxedTupleTyCon (dataConTyCon con) then LFTuple else LFCon) 
+	con (isNullaryDataCon con)
 
 mkSelectorLFInfo rhs_ty offset updatable
   = LFThunk rhs_ty NotTopLevel False updatable (SelectorThunk offset)