[project @ 2001-10-15 15:06:01 by simonpj]

[ghc-hetmet.git] / ghc / compiler / coreSyn / CoreTidy.lhs

diff --git a/ghc/compiler/coreSyn/CoreTidy.lhs b/ghc/compiler/coreSyn/CoreTidy.lhs
index 3407734..4e1a4d5 100644 (file)
--- a/ghc/compiler/coreSyn/CoreTidy.lhs
+++ b/ghc/compiler/coreSyn/CoreTidy.lhs
@@ -5,7 +5,7 @@
 
 \begin{code}
 module CoreTidy (
 
 \begin{code}
 module CoreTidy (

-       tidyCorePgm, tidyExpr, 
+       tidyCorePgm, tidyExpr, tidyCoreExpr,

        tidyBndr, tidyBndrs
     ) where
 
        tidyBndr, tidyBndrs
     ) where
 

@@ -14,45 +14,45 @@ module CoreTidy (
 import CmdLineOpts     ( DynFlags, DynFlag(..), opt_OmitInterfacePragmas )
 import CoreSyn
 import CoreUnfold      ( noUnfolding, mkTopUnfolding, okToUnfoldInHiFile )
 import CmdLineOpts     ( DynFlags, DynFlag(..), opt_OmitInterfacePragmas )
 import CoreSyn
 import CoreUnfold      ( noUnfolding, mkTopUnfolding, okToUnfoldInHiFile )

-import CoreUtils       ( exprArity )

 import CoreFVs         ( ruleSomeFreeVars, exprSomeFreeVars )
 import CoreFVs         ( ruleSomeFreeVars, exprSomeFreeVars )

+import PprCore         ( pprIdCoreRule )

 import CoreLint                ( showPass, endPass )
 import VarEnv
 import VarSet
 import Var             ( Id, Var )
 import CoreLint                ( showPass, endPass )
 import VarEnv
 import VarSet
 import Var             ( Id, Var )

-import Id              ( idType, idInfo, idName, isExportedId,
-                         mkId, isLocalId, omitIfaceSigForId
+import Id              ( idType, idInfo, idName, isExportedId, 
+                         idSpecialisation, idUnique, isDataConWrapId,
+                         mkVanillaGlobal, mkGlobalId, isLocalId, 
+                         isDataConId, mkUserLocal, isGlobalId, globalIdDetails,
+                         idNewDemandInfo, setIdNewDemandInfo, setIdCgInfo,
+                         idNewStrictness, setIdNewStrictness

                        ) 
                        ) 

-import IdInfo          ( IdInfo, mkIdInfo, vanillaIdInfo,
-                         IdFlavour(..), flavourInfo, ppFlavourInfo,
-                         specInfo, setSpecInfo, 
-                         cprInfo, setCprInfo, 
-                         inlinePragInfo, setInlinePragInfo, isNeverInlinePrag,
-                         strictnessInfo, setStrictnessInfo, 
-                         isBottomingStrictness,
-                         unfoldingInfo, setUnfoldingInfo, 
-                         occInfo, isLoopBreaker,
-                         workerInfo, setWorkerInfo, WorkerInfo(..),
-                         ArityInfo(..), setArityInfo
-                       )
+import IdInfo          {- loads of stuff -}
+import NewDemand       ( isBottomingSig, topSig )
+import BasicTypes      ( isNeverActive )

 import Name            ( getOccName, nameOccName, globaliseName, setNameOcc, 
 import Name            ( getOccName, nameOccName, globaliseName, setNameOcc, 

-                         localiseName, mkLocalName, isGlobalName
+                         localiseName, isGlobalName, setNameUnique

                        )
                        )

+import NameEnv         ( filterNameEnv )

 import OccName         ( TidyOccEnv, initTidyOccEnv, tidyOccName )
 import OccName         ( TidyOccEnv, initTidyOccEnv, tidyOccName )

-import Type            ( tidyTopType, tidyType, tidyTyVar )
+import Type            ( tidyTopType, tidyType, tidyTyVarBndr )

 import Module          ( Module, moduleName )
 import Module          ( Module, moduleName )

-import HscTypes                ( PersistentCompilerState( pcs_PRS ), PersistentRenamerState( prsOrig ),
-                         OrigNameEnv( origNames ), OrigNameNameEnv
+import HscTypes                ( PersistentCompilerState( pcs_PRS ), 
+                         PersistentRenamerState( prsOrig ),
+                         NameSupply( nsNames, nsUniqs ),
+                         TypeEnv, extendTypeEnvList, 
+                         ModDetails(..), TyThing(..)

                        )
                        )

-import UniqSupply

 import FiniteMap       ( lookupFM, addToFM )
 import FiniteMap       ( lookupFM, addToFM )

-import Maybes          ( maybeToBool, orElse )
-import ErrUtils                ( showPass )
+import Maybes          ( orElse )
+import ErrUtils                ( showPass, dumpIfSet_core )

 import SrcLoc          ( noSrcLoc )
 import UniqFM          ( mapUFM )
 import SrcLoc          ( noSrcLoc )
 import UniqFM          ( mapUFM )

-import Outputable
+import UniqSupply      ( splitUniqSupply, uniqFromSupply )

 import List            ( partition )
 import Util            ( mapAccumL )
 import List            ( partition )
 import Util            ( mapAccumL )

+import Maybe           ( isJust )
+import Outputable

 \end{code}
 
 
 \end{code}
 
 

@@ -83,28 +83,41 @@ IdEnv Bool
 
 Step 2: Tidy the program
 ~~~~~~~~~~~~~~~~~~~~~~~~
 
 Step 2: Tidy the program
 ~~~~~~~~~~~~~~~~~~~~~~~~

-Next we traverse the bindings top to bottom.  For each top-level
+Next we traverse the bindings top to bottom.  For each *top-level*

 binder
 
 binder
 

-  - Make all external Ids have Global names and vice versa
+ 1. Make it into a GlobalId
+
+ 2. Give it a system-wide Unique.
+    [Even non-exported things need system-wide Uniques because the
+    byte-code generator builds a single Name->BCO symbol table.]
+
+    We use the NameSupply kept in the PersistentRenamerState as the
+    source of such system-wide uniques.
+
+    For external Ids, use the original-name cache in the NameSupply 
+    to ensure that the unique assigned is the same as the Id had 
+    in any previous compilation run.
+  
+ 3. If it's an external Id, make it have a global Name, otherwise
+    make it have a local Name.

     This is used by the code generator to decide whether
     to make the label externally visible
 
     This is used by the code generator to decide whether
     to make the label externally visible
 

-  - Give external ids a "tidy" occurrence name.  This means
+ 4. Give external Ids a "tidy" occurrence name.  This means

     we can print them in interface files without confusing 
     "x" (unique 5) with "x" (unique 10).
   
     we can print them in interface files without confusing 
     "x" (unique 5) with "x" (unique 10).
   

-  - Give external Ids the same Unique as they had before
-    if the name is in the renamer's name cache
-  
-  - Clone all local Ids.  This means that Tidy Core has the property
-    that all Ids are unique, rather than the weaker guarantee of
-    no clashes which the simplifier provides.
+ 5. Give it its UTTERLY FINAL IdInfo; in ptic, 
+       * Its IdDetails becomes VanillaGlobal, reflecting the fact that
+         from now on we regard it as a global, not local, Id

 
 

-  - Give the Id its final IdInfo; in ptic, 
-       * Its flavour becomes ConstantId, reflecting the fact that
-         from now on we regard it as a constant, not local, Id

        * its unfolding, if it should have one
        * its unfolding, if it should have one

+       
+       * its arity, computed from the number of visible lambdas
+
+       * its CAF info, computed from what is free in its RHS
+

                
 Finally, substitute these new top-level binders consistently
 throughout, including in unfoldings.  We also tidy binders in
                
 Finally, substitute these new top-level binders consistently
 throughout, including in unfoldings.  We also tidy binders in

@@ -113,47 +126,144 @@ RHSs, so that they print nicely in interfaces.
 \begin{code}
 tidyCorePgm :: DynFlags -> Module
            -> PersistentCompilerState
 \begin{code}
 tidyCorePgm :: DynFlags -> Module
            -> PersistentCompilerState

-           -> [CoreBind] -> [IdCoreRule]
-           -> IO (PersistentCompilerState, [CoreBind], [IdCoreRule])
-tidyCorePgm dflags mod pcs binds_in orphans_in
+           -> CgInfoEnv                -- Information from the back end,
+                                       -- to be splatted into the IdInfo
+           -> ModDetails
+           -> IO (PersistentCompilerState, ModDetails)
+
+tidyCorePgm dflags mod pcs cg_info_env
+           (ModDetails { md_types = env_tc, md_insts = insts_tc, 
+                         md_binds = binds_in, md_rules = orphans_in })

   = do { showPass dflags "Tidy Core"
 
   = do { showPass dflags "Tidy Core"
 

-       ; let ext_ids = findExternalSet binds_in orphans_in
+       ; let ext_ids   = findExternalSet   binds_in orphans_in
+       ; let ext_rules = findExternalRules binds_in orphans_in ext_ids

 
 

-       ; us <- mkSplitUniqSupply 't' -- for "tidy"
+       -- We also make sure to avoid any exported binders.  Consider
+       --      f{-u1-} = 1     -- Local decl
+       --      ...
+       --      f{-u2-} = 2     -- Exported decl
+       --
+       -- The second exported decl must 'get' the name 'f', so we
+       -- have to put 'f' in the avoids list before we get to the first
+       -- decl.  tidyTopId then does a no-op on exported binders.
+       ; let   prs           = pcs_PRS pcs
+               orig_ns       = prsOrig prs

 
 

-       ; let ((us1, orig_env', occ_env, subst_env), binds_out) 
+               init_tidy_env = (orig_ns, initTidyOccEnv avoids, emptyVarEnv)
+               avoids        = [getOccName bndr | bndr <- bindersOfBinds binds_in,
+                                                  isGlobalName (idName bndr)]
+
+       ; let ((orig_ns', occ_env, subst_env), tidy_binds) 

                        = mapAccumL (tidyTopBind mod ext_ids) 
                        = mapAccumL (tidyTopBind mod ext_ids) 

-                                   (init_tidy_env us) binds_in
+                                   init_tidy_env binds_in

 
 

-       ; let (orphans_out, us2) 
-                  = initUs us1 (tidyIdRules (occ_env,subst_env) orphans_in)
+       ; let tidy_rules = tidyIdRules (occ_env,subst_env) ext_rules

 
 

-       ; let prs' = prs { prsOrig = orig { origNames = orig_env' } }
+       ; let prs' = prs { prsOrig = orig_ns' }

              pcs' = pcs { pcs_PRS = prs' }
 
              pcs' = pcs { pcs_PRS = prs' }
 

-       ; endPass dflags "Tidy Core" Opt_D_dump_simpl binds_out
+       ; let final_ids  = [ addCgInfo cg_info_env id 
+                          | bind <- tidy_binds
+                          , id <- bindersOf bind
+                          , isGlobalName (idName id)]
+
+               -- Dfuns are local Ids that might have
+               -- changed their unique during tidying
+       ; let lookup_dfun_id id = lookupVarEnv subst_env id `orElse` 
+                                 pprPanic "lookup_dfun_id" (ppr id)

 
 

-       ; return (pcs', binds_out, orphans_out)
+
+       ; let tidy_type_env = mkFinalTypeEnv env_tc final_ids
+             tidy_dfun_ids = map lookup_dfun_id insts_tc
+
+       ; let tidy_details = ModDetails { md_types = tidy_type_env,
+                                         md_rules = tidy_rules,
+                                         md_insts = tidy_dfun_ids,
+                                         md_binds = tidy_binds }
+
+       ; endPass dflags "Tidy Core" Opt_D_dump_simpl tidy_binds
+       ; dumpIfSet_core dflags Opt_D_dump_simpl
+               "Tidy Core Rules"
+               (vcat (map pprIdCoreRule tidy_rules))
+
+       ; return (pcs', tidy_details)

        }
        }

+
+addCgInfo :: CgInfoEnv -> Id -> Id
+-- Pin on the info that comes from the code generator
+-- This doesn't make its way into the *bindings* that 
+-- go on to the code generator (that might give black holes etc)
+-- Rather, it's pinned onto the Id in the type environment 
+-- that (a) generates the interface file
+--     (b) in GHCi goes into subsequent compilations
+addCgInfo cg_info_env id 
+  = id `setIdCgInfo` lookupCgInfo cg_info_env (idName id)
+
+tidyCoreExpr :: CoreExpr -> IO CoreExpr
+tidyCoreExpr expr = return (tidyExpr emptyTidyEnv expr)
+\end{code}
+
+
+%************************************************************************
+%*                                                                     *
+\subsection{Write a new interface file}
+%*                                                                     *
+%************************************************************************
+
+\begin{code}
+mkFinalTypeEnv :: TypeEnv      -- From typechecker
+              -> [Id]          -- Final Ids
+              -> TypeEnv
+
+mkFinalTypeEnv type_env final_ids
+  = extendTypeEnvList (filterNameEnv keep_it type_env)
+                     (map AnId final_ids)

   where
   where

-       -- We also make sure to avoid any exported binders.  Consider
-       --      f{-u1-} = 1     -- Local decl
-       --      ...
-       --      f{-u2-} = 2     -- Exported decl
+       -- The competed type environment is gotten from
+       --      a) keeping the types and classes
+       --      b) removing all Ids, 
+       --      c) adding Ids with correct IdInfo, including unfoldings,
+       --              gotten from the bindings
+       -- From (c) we keep only those Ids with Global names;
+       --          the CoreTidy pass makes sure these are all and only
+       --          the externally-accessible ones
+       -- This truncates the type environment to include only the 
+       -- exported Ids and things needed from them, which saves space

        --
        --

-       -- The second exported decl must 'get' the name 'f', so we
-       -- have to put 'f' in the avoids list before we get to the first
-       -- decl.  tidyTopId then does a no-op on exported binders.
-    prs                     = pcs_PRS pcs
-    orig            = prsOrig prs
-    orig_env        = origNames orig
-
-    init_tidy_env us = (us, orig_env, initTidyOccEnv avoids, emptyVarEnv)
-    avoids          = [getOccName bndr | bndr <- bindersOfBinds binds_in,
-                                      isGlobalName (idName bndr)]
+       -- However, we do keep things like constructors, which should not appear 
+       -- in interface files, because they are needed by importing modules when
+       -- using the compilation manager
+
+       -- We keep constructor workers, 
+       -- because they won't appear in the bindings from which final_ids are derived!
+    keep_it (AnId id) = isDataConId id -- Remove all Ids except constructor workers
+    keep_it other     = True           -- Keep all TyCons and Classes

 \end{code}
 
 \end{code}
 

+\begin{code}
+findExternalRules :: [CoreBind]
+                 -> [IdCoreRule] -- Orphan rules
+                 -> IdEnv a      -- Ids that are exported, so we need their rules
+                 -> [IdCoreRule]
+  -- The complete rules are gotten by combining
+  --   a) the orphan rules
+  --   b) rules embedded in the top-level Ids
+findExternalRules binds orphan_rules ext_ids
+  | opt_OmitInterfacePragmas = []
+  | otherwise
+  = orphan_rules ++ local_rules
+  where
+    local_rules  = [ (id, rule)
+                  | id <- bindersOfBinds binds,
+                    id `elemVarEnv` ext_ids,
+                    rule <- rulesRules (idSpecialisation id),
+                    not (isBuiltinRule rule)
+                       -- We can't print builtin rules in interface files
+                       -- Since they are built in, an importing module
+                       -- will have access to them anyway
+                ]
+\end{code}

 
 %************************************************************************
 %*                                                                     *
 
 %************************************************************************
 %*                                                                     *

@@ -163,13 +273,14 @@ tidyCorePgm dflags mod pcs binds_in orphans_in
 
 \begin{code}
 findExternalSet :: [CoreBind] -> [IdCoreRule]
 
 \begin{code}
 findExternalSet :: [CoreBind] -> [IdCoreRule]

-               -> IdEnv Bool   -- True <=> show unfolding
+               -> IdEnv Bool   -- In domain => external
+                               -- Range = True <=> show unfolding

        -- Step 1 from the notes above
 findExternalSet binds orphan_rules
   = foldr find init_needed binds
   where
     orphan_rule_ids :: IdSet
        -- Step 1 from the notes above
 findExternalSet binds orphan_rules
   = foldr find init_needed binds
   where
     orphan_rule_ids :: IdSet

-    orphan_rule_ids = unionVarSets [ ruleSomeFreeVars isIdAndLocal rule 
+    orphan_rule_ids = unionVarSets [ ruleSomeFreeVars isLocalId rule 

                                   | (_, rule) <- orphan_rules]
     init_needed :: IdEnv Bool
     init_needed = mapUFM (\_ -> False) orphan_rule_ids
                                   | (_, rule) <- orphan_rules]
     init_needed :: IdEnv Bool
     init_needed = mapUFM (\_ -> False) orphan_rule_ids

@@ -197,8 +308,6 @@ findExternalSet binds orphan_rules
     need_id needed_set id       = id `elemVarEnv` needed_set || isExportedId id 
     need_pr needed_set (id,rhs)        = need_id needed_set id
 
     need_id needed_set id       = id `elemVarEnv` needed_set || isExportedId id 
     need_pr needed_set (id,rhs)        = need_id needed_set id
 

-isIdAndLocal id = isId id && isLocalId id
-

 addExternal :: (Id,CoreExpr) -> IdEnv Bool -> IdEnv Bool
 -- The Id is needed; extend the needed set
 -- with it and its dependents (free vars etc)
 addExternal :: (Id,CoreExpr) -> IdEnv Bool -> IdEnv Bool
 -- The Id is needed; extend the needed set
 -- with it and its dependents (free vars etc)

@@ -216,9 +325,9 @@ addExternal (id,rhs) needed
                                                spec_ids
 
     idinfo        = idInfo id
                                                spec_ids
 
     idinfo        = idInfo id

-    dont_inline           = isNeverInlinePrag (inlinePragInfo idinfo)
+    dont_inline           = isNeverActive (inlinePragInfo idinfo)

     loop_breaker   = isLoopBreaker (occInfo idinfo)
     loop_breaker   = isLoopBreaker (occInfo idinfo)

-    bottoming_fn   = isBottomingStrictness (strictnessInfo idinfo)
+    bottoming_fn   = isBottomingSig (newStrictnessInfo idinfo `orElse` topSig)

     spec_ids      = rulesRhsFreeVars (specInfo idinfo)
     worker_info           = workerInfo idinfo
 
     spec_ids      = rulesRhsFreeVars (specInfo idinfo)
     worker_info           = workerInfo idinfo
 

@@ -238,7 +347,7 @@ addExternal (id,rhs) needed
                  rhs_is_small           &&     -- Small enough
                  okToUnfoldInHiFile rhs        -- No casms etc
 
                  rhs_is_small           &&     -- Small enough
                  okToUnfoldInHiFile rhs        -- No casms etc
 

-    unfold_ids | show_unfold = exprSomeFreeVars isIdAndLocal rhs
+    unfold_ids | show_unfold = exprSomeFreeVars isLocalId rhs

               | otherwise   = emptyVarSet
 
     worker_ids = case worker_info of
               | otherwise   = emptyVarSet
 
     worker_ids = case worker_info of

@@ -255,10 +364,11 @@ addExternal (id,rhs) needed
 
 
 \begin{code}
 
 
 \begin{code}

-type TopTidyEnv = (UniqSupply, OrigNameNameEnv, TidyOccEnv, VarEnv Var)
+type TopTidyEnv = (NameSupply, TidyOccEnv, VarEnv Var)

 
 -- TopTidyEnv: when tidying we need to know
 
 -- TopTidyEnv: when tidying we need to know

---   * orig_env: Any pre-ordained Names.  These may have arisen because the
+--   * ns: The NameSupply, containing a unique supply and any pre-ordained Names.  
+--       These may have arisen because the

 --       renamer read in an interface file mentioning M.$wf, say,
 --       and assigned it unique r77.  If, on this compilation, we've
 --       invented an Id whose name is $wf (but with a different unique)
 --       renamer read in an interface file mentioning M.$wf, say,
 --       and assigned it unique r77.  If, on this compilation, we've
 --       invented an Id whose name is $wf (but with a different unique)

@@ -269,9 +379,6 @@ type TopTidyEnv = (UniqSupply, OrigNameNameEnv, TidyOccEnv, VarEnv Var)
 --     are 'used'
 --
 --   * subst_env: A Var->Var mapping that substitutes the new Var for the old
 --     are 'used'
 --
 --   * subst_env: A Var->Var mapping that substitutes the new Var for the old

---
---   * uniqsuppy: so we can clone any Ids with non-preordained names.
---

 \end{code}
 
 
 \end{code}
 
 

@@ -282,40 +389,61 @@ tidyTopBind :: Module
            -> TopTidyEnv -> CoreBind
            -> (TopTidyEnv, CoreBind)
 
            -> TopTidyEnv -> CoreBind
            -> (TopTidyEnv, CoreBind)
 

-tidyTopBind mod ext_ids env (NonRec bndr rhs)
-  = ((us2,orig,occ,subst) , NonRec bndr' rhs')
+tidyTopBind mod ext_ids top_tidy_env (NonRec bndr rhs)
+  = ((orig,occ,subst) , NonRec bndr' rhs')

   where
   where

-    (env1@(us1,orig,occ,subst), bndr') = tidyTopBinder mod ext_ids env rhs' env bndr
-    (rhs',us2)   = initUs us1 (tidyTopRhs env1 rhs)
+    ((orig,occ,subst), bndr')
+        = tidyTopBinder mod ext_ids rec_tidy_env rhs' top_tidy_env bndr
+    rec_tidy_env = (occ,subst)
+    rhs' = tidyExpr rec_tidy_env rhs

 
 

-tidyTopBind mod ext_ids env (Rec prs)
+tidyTopBind mod ext_ids top_tidy_env (Rec prs)

   = (final_env, Rec prs')
   where
   = (final_env, Rec prs')
   where

-    (final_env, prs')     = mapAccumL do_one env prs
+    (final_env@(_,occ,subst), prs') = mapAccumL do_one top_tidy_env prs
+    rec_tidy_env = (occ,subst)

 
 

-    do_one env (bndr,rhs) 
-       = ((us',orig,occ,subst), (bndr',rhs'))
+    do_one top_tidy_env (bndr,rhs) 
+       = ((orig,occ,subst), (bndr',rhs'))

        where
        where

-       (env'@(us,orig,occ,subst), bndr') 
-               = tidyTopBinder mod ext_ids final_env rhs' env bndr
-        (rhs', us') = initUs us (tidyTopRhs final_env rhs)
-
-
-tidyTopRhs :: TopTidyEnv -> CoreExpr -> UniqSM CoreExpr
-       -- Just an impedence matcher
-tidyTopRhs (_, _, occ_env, subst_env) rhs
-  = tidyExpr (occ_env, subst_env) rhs
+       ((orig,occ,subst), bndr')
+          = tidyTopBinder mod ext_ids
+               rec_tidy_env rhs' top_tidy_env bndr

 
 

+        rhs' = tidyExpr rec_tidy_env rhs

 
 tidyTopBinder :: Module -> IdEnv Bool
 
 tidyTopBinder :: Module -> IdEnv Bool

-             -> TopTidyEnv -> CoreExpr
+             -> TidyEnv -> CoreExpr
+                       -- The TidyEnv is used to tidy the IdInfo
+                       -- The expr is the already-tided RHS
+                       -- Both are knot-tied: don't look at them!

              -> TopTidyEnv -> Id -> (TopTidyEnv, Id)
              -> TopTidyEnv -> Id -> (TopTidyEnv, Id)

-tidyTopBinder mod ext_ids 
-       final_env@(_,  orig_env1, occ_env1, subst_env1) rhs 
-             env@(us, orig_env2, occ_env2, subst_env2) id
+  -- NB: tidyTopBinder doesn't affect the unique supply
+
+tidyTopBinder mod ext_ids tidy_env rhs
+             env@(ns2, occ_env2, subst_env2) id
+
+  | isDataConWrapId id -- Don't tidy constructor wrappers
+  = (env, id)          -- The Id is stored in the TyCon, so it would be bad
+                       -- if anything changed
+
+-- HACK ALERT: we *do* tidy record selectors.  Reason: they mention error
+-- messages, which may be floated out:
+--     x_field pt = case pt of
+--                     Rect x y -> y
+--                     Pol _ _  -> error "buggle wuggle"
+-- The error message will be floated out so we'll get
+--     lvl5 = error "buggle wuggle"
+--     x_field pt = case pt of
+--                     Rect x y -> y
+--                     Pol _ _  -> lvl5
+--
+-- When this happens, it's vital that the Id exposed to importing modules
+-- (by ghci) mentions lvl5 in its unfolding, not the un-tidied version.
+-- 
+-- What about the Id in the TyCon?  It probably shouldn't be in the TyCon at
+-- all, but in any case it will have the error message inline so it won't matter.

 
 

-  | omitIfaceSigForId id       -- Don't mess with constructors, 
-  = (env, id)                  -- record selectors, and the like

 
   | otherwise
        -- This function is the heart of Step 2
 
   | otherwise
        -- This function is the heart of Step 2

@@ -326,121 +454,112 @@ tidyTopBinder mod ext_ids
 
        -- The rhs is already tidied
        
 
        -- The rhs is already tidied
        

-  = ((us_r, orig_env', occ_env', subst_env'), id')
+  = ((orig_env', occ_env', subst_env'), id')

   where
   where

-    (us_l, us_r)    = splitUniqSupply us
-
-    (orig_env', occ_env', name') = tidyTopName mod orig_env2 occ_env2
+    (orig_env', occ_env', name') = tidyTopName mod ns2 occ_env2

                                               is_external
                                               (idName id)
                                               is_external
                                               (idName id)

-    ty'                    = tidyTopType (idType id)
-    idinfo'         = tidyIdInfo us_l (occ_env1, subst_env1)
-                        is_external unfold_info arity_info id
+    ty'            = tidyTopType (idType id)
+    idinfo' = tidyIdInfo tidy_env is_external unfold_info id
+
+    id' | isGlobalId id = mkGlobalId (globalIdDetails id) name' ty' idinfo'
+       | otherwise     = mkVanillaGlobal                 name' ty' idinfo'
+       -- The test ensures that record selectors (which must be tidied; see above)
+       -- retain their details.  If it's forgotten, importing modules get confused.

 
 

-    id'               = mkId name' ty' idinfo'

     subst_env' = extendVarEnv subst_env2 id id'
 
     maybe_external = lookupVarEnv ext_ids id
     subst_env' = extendVarEnv subst_env2 id id'
 
     maybe_external = lookupVarEnv ext_ids id

-    is_external    = maybeToBool maybe_external
+    is_external    = isJust maybe_external

 
     -- Expose an unfolding if ext_ids tells us to
     show_unfold = maybe_external `orElse` False
     unfold_info | show_unfold = mkTopUnfolding rhs
                | otherwise   = noUnfolding
 
 
     -- Expose an unfolding if ext_ids tells us to
     show_unfold = maybe_external `orElse` False
     unfold_info | show_unfold = mkTopUnfolding rhs
                | otherwise   = noUnfolding
 

-    arity_info = exprArity rhs

 
 

-
-tidyIdInfo us tidy_env is_external unfold_info arity_info id
+tidyIdInfo tidy_env is_external unfold_info id

   | opt_OmitInterfacePragmas || not is_external
        -- No IdInfo if the Id isn't external, or if we don't have -O
   | opt_OmitInterfacePragmas || not is_external
        -- No IdInfo if the Id isn't external, or if we don't have -O

-  = mkIdInfo new_flavour 
-       `setStrictnessInfo` strictnessInfo core_idinfo
-       `setArityInfo`      ArityExactly arity_info
-       -- Keep strictness and arity info; it's used by the code generator
+  = vanillaIdInfo 
+       `setArityInfo`         arityInfo core_idinfo
+       `setNewStrictnessInfo` newStrictnessInfo core_idinfo
+       -- Keep strictness and arity; both are used by CorePrep

 
   | otherwise
 
   | otherwise

-  =  let (rules', _) = initUs us (tidyRules  tidy_env (specInfo core_idinfo))
-     in
-     mkIdInfo new_flavour
-       `setCprInfo`        cprInfo core_idinfo
-       `setStrictnessInfo` strictnessInfo core_idinfo
-       `setInlinePragInfo` inlinePragInfo core_idinfo
-       `setUnfoldingInfo`  unfold_info
-       `setWorkerInfo`     tidyWorker tidy_env (workerInfo core_idinfo)
-       `setSpecInfo`       rules'
-       `setArityInfo`      ArityExactly arity_info
-               -- this is the final IdInfo, it must agree with the
-               -- code finally generated (i.e. NO more transformations
-               -- after this!).
+  =  vanillaIdInfo 
+       `setArityInfo`         arityInfo core_idinfo
+       `setNewStrictnessInfo` newStrictnessInfo core_idinfo
+       `setInlinePragInfo`    inlinePragInfo core_idinfo
+       `setUnfoldingInfo`     unfold_info
+       `setWorkerInfo`        tidyWorker tidy_env (workerInfo core_idinfo)
+       -- NB: we throw away the Rules
+       -- They have already been extracted by findExternalRules

   where
     core_idinfo = idInfo id
 
   where
     core_idinfo = idInfo id
 

-       -- A DFunId must stay a DFunId, so that we can gather the
-       -- DFunIds up later.  Other local things become ConstantIds.
-    new_flavour = case flavourInfo core_idinfo of
-                   VanillaId  -> ConstantId
-                   ExportedId -> ConstantId
-                   ConstantId -> ConstantId    -- e.g. Default methods
-                   DictFunId  -> DictFunId
-                   flavour    -> pprTrace "tidyIdInfo" (ppr id <+> ppFlavourInfo flavour)
-                                 flavour
-
--- this is where we set names to local/global based on whether they really are 
+
+-- This is where we set names to local/global based on whether they really are 

 -- externally visible (see comment at the top of this module).  If the name
 -- was previously local, we have to give it a unique occurrence name if
 -- we intend to globalise it.
 -- externally visible (see comment at the top of this module).  If the name
 -- was previously local, we have to give it a unique occurrence name if
 -- we intend to globalise it.

-tidyTopName mod orig_env occ_env external name
-  | global && internal = (orig_env, occ_env, localiseName name)
-  | local  && internal = (orig_env, occ_env', setNameOcc name occ') -- (*)
-  | global && external = (orig_env, occ_env, name)
-  | local  && external = globalise
-       -- (*) just in case we're globalising all top-level names (because of
-       -- -split-objs), we need to give *all* the top-level ids a 
-       -- unique occurrence name.  The actual globalisation now happens in the code
-       -- generator.
-  where
+tidyTopName mod ns occ_env external name
+  | global && internal = (ns, occ_env, localiseName name)
+
+  | global && external = (ns, occ_env, name)
+       -- Global names are assumed to have been allocated by the renamer,
+       -- so they already have the "right" unique
+       -- And it's a system-wide unique too
+
+  | local  && internal = (ns { nsUniqs = us2 }, occ_env', unique_name)
+       -- Even local, internal names must get a unique occurrence, because
+       -- if we do -split-objs we globalise the name later, in the code generator
+       --
+       -- Similarly, we must make sure it has a system-wide Unique, because
+       -- the byte-code generator builds a system-wide Name->BCO symbol table
+
+  | local  && external = case lookupFM ns_names key of
+                          Just orig -> (ns,                                        occ_env', orig)
+                          Nothing   -> (ns { nsUniqs = us2, nsNames = ns_names' }, occ_env', global_name)

        -- If we want to globalise a currently-local name, check
        -- whether we have already assigned a unique for it.
        -- If so, use it; if not, extend the table
        -- If we want to globalise a currently-local name, check
        -- whether we have already assigned a unique for it.
        -- If so, use it; if not, extend the table

-    globalise 
-       = case lookupFM orig_env key of
-         Just orig -> (orig_env,                         occ_env', orig)
-         Nothing   -> (addToFM orig_env key global_name, occ_env', global_name)

 
 

-    (occ_env', occ') = tidyOccName occ_env (nameOccName name)
-    key                     = (moduleName mod, occ')
-    global_name      = globaliseName (setNameOcc name occ') mod
+  where

     global          = isGlobalName name
     local           = not global
     internal        = not external
 
     global          = isGlobalName name
     local           = not global
     internal        = not external
 

-tidyIdRules :: TidyEnv -> [IdCoreRule] -> UniqSM [IdCoreRule]
-tidyIdRules env [] = returnUs []
-tidyIdRules env ((fn,rule) : rules)
-  = tidyRule env rule                  `thenUs` \ rule ->
-    tidyIdRules env rules      `thenUs` \ rules ->
-    returnUs ((tidyVarOcc env fn, rule) : rules)
+    (occ_env', occ') = tidyOccName occ_env (nameOccName name)
+    key                     = (moduleName mod, occ')
+    ns_names        = nsNames ns
+    ns_uniqs        = nsUniqs ns
+    (us1, us2)      = splitUniqSupply ns_uniqs
+    unique_name             = setNameUnique (setNameOcc name occ') (uniqFromSupply us1)
+    global_name      = globaliseName unique_name mod
+    ns_names'       = addToFM ns_names key global_name
+

 
 

+------------  Worker  --------------

 tidyWorker tidy_env (HasWorker work_id wrap_arity) 
   = HasWorker (tidyVarOcc tidy_env work_id) wrap_arity
 tidyWorker tidy_env (HasWorker work_id wrap_arity) 
   = HasWorker (tidyVarOcc tidy_env work_id) wrap_arity

-tidyWorker tidy_env NoWorker
+tidyWorker tidy_env other

   = NoWorker
 
   = NoWorker
 

-tidyRules :: TidyEnv -> CoreRules -> UniqSM CoreRules
-tidyRules env (Rules rules fvs) 
-  = mapUs (tidyRule env) rules                 `thenUs` \ rules ->
-    returnUs (Rules rules (foldVarSet tidy_set_elem emptyVarSet fvs))
-  where
-    tidy_set_elem var new_set = extendVarSet new_set (tidyVarOcc env var)
-
-tidyRule :: TidyEnv -> CoreRule -> UniqSM CoreRule
-tidyRule env rule@(BuiltinRule _) = returnUs rule
-tidyRule env (Rule name vars tpl_args rhs)
-  = tidyBndrs env vars                 `thenUs` \ (env', vars) ->
-    mapUs (tidyExpr env') tpl_args     `thenUs` \ tpl_args ->
-    tidyExpr env' rhs                  `thenUs` \ rhs ->
-    returnUs (Rule name vars tpl_args rhs)
+------------  Rules  --------------
+tidyIdRules :: TidyEnv -> [IdCoreRule] -> [IdCoreRule]
+tidyIdRules env [] = []
+tidyIdRules env ((fn,rule) : rules)
+  = tidyRule env rule                  =: \ rule ->
+    tidyIdRules env rules      =: \ rules ->
+     ((tidyVarOcc env fn, rule) : rules)
+
+tidyRule :: TidyEnv -> CoreRule -> CoreRule
+tidyRule env rule@(BuiltinRule _ _) = rule
+tidyRule env (Rule name act vars tpl_args rhs)
+  = tidyBndrs env vars                 =: \ (env', vars) ->
+    map (tidyExpr env') tpl_args       =: \ tpl_args ->
+     (Rule name act vars tpl_args (tidyExpr env' rhs))

 \end{code}
 
 %************************************************************************
 \end{code}
 
 %************************************************************************

@@ -452,51 +571,40 @@ tidyRule env (Rule name vars tpl_args rhs)
 \begin{code}
 tidyBind :: TidyEnv
         -> CoreBind
 \begin{code}
 tidyBind :: TidyEnv
         -> CoreBind

-        -> UniqSM (TidyEnv, CoreBind)
+        ->  (TidyEnv, CoreBind)
+

 tidyBind env (NonRec bndr rhs)
 tidyBind env (NonRec bndr rhs)

-  = tidyBndrWithRhs env (bndr,rhs) `thenUs` \ (env', bndr') ->
-    tidyExpr env' rhs                     `thenUs` \ rhs' ->
-    returnUs (env', NonRec bndr' rhs')
+  = tidyLetBndr env (bndr,rhs)         =: \ (env', bndr') ->
+    (env', NonRec bndr' (tidyExpr env' rhs))

 
 tidyBind env (Rec prs)
 
 tidyBind env (Rec prs)

-  = mapAccumLUs tidyBndrWithRhs env prs        `thenUs` \ (env', bndrs') ->
-    mapUs (tidyExpr env') (map snd prs)                `thenUs` \ rhss' ->
-    returnUs (env', Rec (zip bndrs' rhss'))
+  = mapAccumL tidyLetBndr env prs      =: \ (env', bndrs') ->
+    map (tidyExpr env') (map snd prs)  =: \ rhss' ->
+    (env', Rec (zip bndrs' rhss'))

 
 

-tidyExpr env (Var v)   = returnUs (Var (tidyVarOcc env v))
-tidyExpr env (Type ty) = returnUs (Type (tidyType env ty))
-tidyExpr env (Lit lit) = returnUs (Lit lit)

 
 

-tidyExpr env (App f a)
-  = tidyExpr env f             `thenUs` \ f ->
-    tidyExpr env a             `thenUs` \ a ->
-    returnUs (App f a)
-
-tidyExpr env (Note n e)
-  = tidyExpr env e             `thenUs` \ e ->
-    returnUs (Note (tidyNote env n) e)
+tidyExpr env (Var v)           =  Var (tidyVarOcc env v)
+tidyExpr env (Type ty)         =  Type (tidyType env ty)
+tidyExpr env (Lit lit)         =  Lit lit
+tidyExpr env (App f a)         =  App (tidyExpr env f) (tidyExpr env a)
+tidyExpr env (Note n e) =  Note (tidyNote env n) (tidyExpr env e)

 
 tidyExpr env (Let b e) 
 
 tidyExpr env (Let b e) 

-  = tidyBind env b             `thenUs` \ (env', b') ->
-    tidyExpr env' e            `thenUs` \ e ->
-    returnUs (Let b' e)
+  = tidyBind env b     =: \ (env', b') ->
+    Let b' (tidyExpr env' e)

 
 tidyExpr env (Case e b alts)
 
 tidyExpr env (Case e b alts)

-  = tidyExpr env e             `thenUs` \ e ->
-    tidyBndr env b             `thenUs` \ (env', b) ->
-    mapUs (tidyAlt env') alts  `thenUs` \ alts ->
-    returnUs (Case e b alts)
+  = tidyBndr env b     =: \ (env', b) ->
+    Case (tidyExpr env e) b (map (tidyAlt env') alts)

 
 tidyExpr env (Lam b e)
 
 tidyExpr env (Lam b e)

-  = tidyBndr env b             `thenUs` \ (env', b) ->
-    tidyExpr env' e            `thenUs` \ e ->
-    returnUs (Lam b e)
+  = tidyBndr env b     =: \ (env', b) ->
+    Lam b (tidyExpr env' e)

 
 
 tidyAlt env (con, vs, rhs)
 
 
 tidyAlt env (con, vs, rhs)

-  = tidyBndrs env vs           `thenUs` \ (env', vs) ->
-    tidyExpr env' rhs          `thenUs` \ rhs ->
-    returnUs (con, vs, rhs)
+  = tidyBndrs env vs   =: \ (env', vs) ->
+    (con, vs, tidyExpr env' rhs)

 
 tidyNote env (Coerce t1 t2)  = Coerce (tidyType env t1) (tidyType env t2)
 tidyNote env note            = note
 
 tidyNote env (Coerce t1 t2)  = Coerce (tidyType env t1) (tidyType env t2)
 tidyNote env note            = note

@@ -515,37 +623,55 @@ tidyVarOcc (_, var_env) v = case lookupVarEnv var_env v of
                                  Nothing -> v
 
 -- tidyBndr is used for lambda and case binders
                                  Nothing -> v
 
 -- tidyBndr is used for lambda and case binders

-tidyBndr :: TidyEnv -> Var -> UniqSM (TidyEnv, Var)
+tidyBndr :: TidyEnv -> Var -> (TidyEnv, Var)

 tidyBndr env var
 tidyBndr env var

-  | isTyVar var = returnUs (tidyTyVar env var)
-  | otherwise   = tidyId env var vanillaIdInfo
-
-tidyBndrs :: TidyEnv -> [Var] -> UniqSM (TidyEnv, [Var])
-tidyBndrs env vars = mapAccumLUs tidyBndr env vars
-
--- tidyBndrWithRhs is used for let binders
-tidyBndrWithRhs :: TidyEnv -> (Var, CoreExpr) -> UniqSM (TidyEnv, Var)
-tidyBndrWithRhs env (id,rhs)
-   = tidyId env id idinfo
-   where
-       idinfo = vanillaIdInfo `setArityInfo` ArityExactly (exprArity rhs)
-                       -- NB: This throws away the IdInfo of the Id, which we
-                       -- no longer need.  That means we don't need to
-                       -- run over it with env, nor renumber it.
-
-tidyId :: TidyEnv -> Id -> IdInfo -> UniqSM (TidyEnv, Id)
-tidyId env@(tidy_env, var_env) id idinfo
+  | isTyVar var = tidyTyVarBndr env var
+  | otherwise   = tidyIdBndr env var
+
+tidyBndrs :: TidyEnv -> [Var] -> (TidyEnv, [Var])
+tidyBndrs env vars = mapAccumL tidyBndr env vars
+
+tidyLetBndr :: TidyEnv -> (Id, CoreExpr) -> (TidyEnv, Var)
+-- Used for local (non-top-level) let(rec)s
+tidyLetBndr env (id,rhs) 
+  = ((tidy_env,new_var_env), final_id)
+  where
+    ((tidy_env,var_env), new_id) = tidyIdBndr env id
+
+       -- We need to keep around any interesting strictness and demand info
+       -- because later on we may need to use it when converting to A-normal form.
+       -- eg.
+       --      f (g x),  where f is strict in its argument, will be converted
+       --      into  case (g x) of z -> f z  by CorePrep, but only if f still
+       --      has its strictness info.
+       --
+       -- Similarly for the demand info - on a let binder, this tells 
+       -- CorePrep to turn the let into a case.
+    final_id = new_id `setIdNewDemandInfo` idNewDemandInfo id
+                     `setIdNewStrictness` idNewStrictness id
+
+    -- Override the env we get back from tidyId with the new IdInfo
+    -- so it gets propagated to the usage sites.
+    new_var_env = extendVarEnv var_env id final_id
+
+tidyIdBndr :: TidyEnv -> Id -> (TidyEnv, Id)
+tidyIdBndr env@(tidy_env, var_env) id

   =    -- Non-top-level variables
   =    -- Non-top-level variables

-    getUniqueUs   `thenUs` \ uniq ->

     let 
        -- Give the Id a fresh print-name, *and* rename its type
        -- The SrcLoc isn't important now, 
        -- though we could extract it from the Id
     let 
        -- Give the Id a fresh print-name, *and* rename its type
        -- The SrcLoc isn't important now, 
        -- though we could extract it from the Id

-       name'             = mkLocalName uniq occ' noSrcLoc
+       -- 
+       -- All local Ids now have the same IdInfo, which should save some
+       -- space.

        (tidy_env', occ') = tidyOccName tidy_env (getOccName id)
        (tidy_env', occ') = tidyOccName tidy_env (getOccName id)

-        ty'              = tidyType (tidy_env,var_env) (idType id)
-       id'               = mkId name' ty' idinfo
+        ty'              = tidyType env (idType id)
+       id'               = mkUserLocal occ' (idUnique id) ty' noSrcLoc

        var_env'          = extendVarEnv var_env id id'
     in
        var_env'          = extendVarEnv var_env id id'
     in

-    returnUs ((tidy_env', var_env'), id')
+     ((tidy_env', var_env'), id')
+\end{code}
+
+\begin{code}
+m =: k = m `seq` k m

 \end{code}
 \end{code}