From: simonpj@microsoft.com <unknown>
Date: Thu, 20 Dec 2007 13:19:12 +0000 (+0000)
Subject: Fix Trac #1988; keep the ru_fn field of a RULE up to date
X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=commitdiff_plain;h=ca919ae01e81fb4afb2243bb34eceff56ca66043

Fix Trac #1988; keep the ru_fn field of a RULE up to date

The ru_fn field was wrong when we moved RULES from one Id to another.
The fix is simple enough.

However, looking at this makes me realise that the worker/wrapper stuff
for recursive newtypes isn't very clever: we generate demand info but
then don't properly exploit it.

This patch fixes the crash though.
---

diff --git a/compiler/basicTypes/IdInfo.lhs b/compiler/basicTypes/IdInfo.lhs
index e64e255..7eacbd8 100644
--- a/compiler/basicTypes/IdInfo.lhs
+++ b/compiler/basicTypes/IdInfo.lhs
@@ -72,7 +72,7 @@ module IdInfo (
 
 	-- Specialisation
 	SpecInfo(..), specInfo, setSpecInfo, isEmptySpecInfo, 
-	specInfoFreeVars, specInfoRules, seqSpecInfo,
+	specInfoFreeVars, specInfoRules, seqSpecInfo, setSpecInfoHead,
 
 	-- CAF info
 	CafInfo(..), cafInfo, ppCafInfo, setCafInfo, mayHaveCafRefs,
@@ -89,6 +89,7 @@ module IdInfo (
 import CoreSyn
 import Class
 import PrimOp
+import Name
 import Var
 import VarSet
 import BasicTypes
@@ -102,7 +103,6 @@ import Module
 import Data.Maybe
 
 #ifdef OLD_STRICTNESS
-import Name
 import Demand
 import qualified Demand
 import Util
@@ -474,7 +474,9 @@ type InlinePragInfo = Activation
 data SpecInfo 
   = SpecInfo 
 	[CoreRule] 
-	VarSet		-- Locally-defined free vars of *both* LHS and RHS of rules
+	VarSet		-- Locally-defined free vars of *both* LHS and RHS 
+			-- of rules.  I don't think it needs to include the
+			-- ru_fn though.
 			-- Note [Rule dependency info]
 
 emptySpecInfo :: SpecInfo
@@ -489,6 +491,12 @@ specInfoFreeVars (SpecInfo _ fvs) = fvs
 specInfoRules :: SpecInfo -> [CoreRule]
 specInfoRules (SpecInfo rules _) = rules
 
+setSpecInfoHead :: Name -> SpecInfo -> SpecInfo
+setSpecInfoHead fn (SpecInfo rules fvs)
+  = SpecInfo (map set_head rules) fvs
+  where
+    set_head rule = rule { ru_fn = fn }
+
 seqSpecInfo (SpecInfo rules fvs) = seqRules rules `seq` seqVarSet fvs
 \end{code}
 
@@ -500,7 +508,7 @@ Consider
 	x = y
  	RULE f x = 4
 Then if we substitute y for x, we'd better do so in the
- rule's LHS too, so we'd better ensure the dependency is respsected
+ rule's LHS too, so we'd better ensure the dependency is respected
 
 
 
diff --git a/compiler/simplCore/SimplCore.lhs b/compiler/simplCore/SimplCore.lhs
index e2ac668..844c401 100644
--- a/compiler/simplCore/SimplCore.lhs
+++ b/compiler/simplCore/SimplCore.lhs
@@ -29,7 +29,7 @@ import Rules		( RuleBase, emptyRuleBase, mkRuleBase, unionRuleBase,
 import PprCore		( pprCoreBindings, pprCoreExpr, pprRules )
 import OccurAnal	( occurAnalysePgm, occurAnalyseExpr )
 import IdInfo		( setNewStrictnessInfo, newStrictnessInfo, 
-			  setWorkerInfo, workerInfo,
+			  setWorkerInfo, workerInfo, setSpecInfoHead,
 			  setInlinePragInfo, inlinePragInfo,
 			  setSpecInfo, specInfo, specInfoRules )
 import CoreUtils	( coreBindsSize )
@@ -700,6 +700,9 @@ transferIdInfo exported_id local_id
     transfer exp_info = exp_info `setNewStrictnessInfo` newStrictnessInfo local_info
 				 `setWorkerInfo`        workerInfo local_info
 				 `setInlinePragInfo`	inlinePragInfo local_info
-				 `setSpecInfo`	        addSpecInfo (specInfo exp_info)
-							            (specInfo local_info)
+				 `setSpecInfo`	        addSpecInfo (specInfo exp_info) new_info
+    new_info = setSpecInfoHead (idName exported_id) 
+			       (specInfo local_info)
+	-- Remember to set the function-name field of the
+	-- rules as we transfer them from one function to another
 \end{code}
diff --git a/compiler/simplCore/Simplify.lhs b/compiler/simplCore/Simplify.lhs
index 3f32459..9723dfb 100644
--- a/compiler/simplCore/Simplify.lhs
+++ b/compiler/simplCore/Simplify.lhs
@@ -1329,7 +1329,7 @@ where x::F Int.  Then we'd like to rewrite (F Int) to Int, getting
 	   I# x# -> let x = x' `cast` sym co 
 		    in rhs
 
-so that 'rhs' can take advantage of hte form of x'.  Notice that Note
+so that 'rhs' can take advantage of the form of x'.  Notice that Note
 [Case of cast] may then apply to the result.
 
 This showed up in Roman's experiments.  Example: