X-Git-Url: http://andersk.mit.edu/gitweb/splint.git/blobdiff_plain/cd7d9b17c558f5857f07f55865d5378fd1ad7c41..508533c52d02429894d89b95224577d8e3cf3c48:/src/transferChecks.c

diff --git a/src/transferChecks.c b/src/transferChecks.c
index bac3b5f..4efa027 100644
--- a/src/transferChecks.c
+++ b/src/transferChecks.c
@@ -1,6 +1,6 @@
 /*
-** LCLint - annotation-assisted static program checker
-** Copyright (C) 1994-2001 University of Virginia,
+** Splint - annotation-assisted static program checker
+** Copyright (C) 1994-2002 University of Virginia,
 **         Massachusetts Institute of Technology
 **
 ** This program is free software; you can redistribute it and/or modify it
@@ -17,18 +17,32 @@
 ** the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
 ** MA 02111-1307, USA.
 **
-** For information on lclint: lclint-request@cs.virginia.edu
-** To report a bug: lclint-bug@cs.virginia.edu
-** For more information: http://lclint.cs.virginia.edu
+** For information on splint: info@splint.org
+** To report a bug: splint-bug@splint.org
+** For more information: http://www.splint.org
 */
 /*
 ** transferChecks.c
 */
 
-# include "lclintMacros.nf"
+# include "splintMacros.nf"
 # include "basic.h"
 # include "transferChecks.h"
 
+/* transfer types: */
+typedef enum
+{
+  TT_FCNRETURN,
+  TT_DOASSIGN,
+  TT_FIELDASSIGN,
+  TT_FCNPASS,
+  TT_GLOBPASS,
+  TT_GLOBRETURN,
+  TT_PARAMRETURN,
+  TT_LEAVETRANS,
+  TT_GLOBINIT
+} transferKind;
+
 static void checkStructTransfer (exprNode p_lhs, sRef p_slhs, exprNode p_rhs, sRef p_srhs,
 				 fileloc p_loc, transferKind p_tt);
 static void checkMetaStateConsistent (/*@exposed@*/ sRef p_fref, sRef p_tref, 
@@ -37,6 +51,7 @@ static void checkMetaStateConsistent (/*@exposed@*/ sRef p_fref, sRef p_tref,
 static void checkLeaveTrans (uentry p_actual, transferKind p_transferType);
 static void checkTransfer (exprNode p_fexp, /*@dependent@*/ sRef p_fref,
 			   exprNode p_texp, /*@dependent@*/ sRef p_tref, 
+			   exprNode p_fcn, /* for printing better error messages */
 			   fileloc p_loc, transferKind p_transferType);
 static void checkGlobTrans (uentry p_glob, transferKind p_type);
 
@@ -94,7 +109,7 @@ transferErrorMessage (transferKind transferType, alkind tkind) /*@*/
 }
 
 static /*@only@*/ cstring
-transferErrorExcerpt (transferKind transferType, exprNode fexp, exprNode texp) /*@*/ 
+transferErrorExcerpt (transferKind transferType, exprNode fexp, exprNode texp, exprNode fcn) /*@*/ 
 {
   switch (transferType)
     {
@@ -105,8 +120,16 @@ transferErrorExcerpt (transferKind transferType, exprNode fexp, exprNode texp) /
     case TT_GLOBINIT:
       return (message ("%s = %s", exprNode_unparse (texp), exprNode_unparse (fexp)));
     case TT_FCNPASS:
-      /*@i32 make it so called fcn is known here! */
-      return cstring_copy (exprNode_unparse (fexp)); 
+      if (exprNode_isDefined (fcn))
+	{
+	  return message ("%s(..., %s, ...)",
+			  exprNode_unparse (fcn),
+			  exprNode_unparse (fexp));
+	}
+      else
+	{
+	  return cstring_copy (exprNode_unparse (fexp));  
+	}
     BADDEFAULT;
     }
   BADEXIT;
@@ -296,7 +319,7 @@ checkCompletelyDefined (exprNode fexp, /*@exposed@*/ sRef fref, sRef ofref,
 	 ("Check definition limit exceeded, checking %q. "
 	  "This either means there is a variable with at least "
 	  "%d indirections apparent in the program text, or "
-	  "there is a bug in LCLint.",
+	  "there is a bug in Splint.",
 	  sRef_unparse (fref),
 	  MAXDEPTH));
 
@@ -482,7 +505,8 @@ checkCompletelyDefined (exprNode fexp, /*@exposed@*/ sRef fref, sRef ofref,
 	    {
 	      ; /* no error (will be a definition error) */
 	    }
-	  else if (transferType == TT_DOASSIGN)
+	  else if (transferType == TT_DOASSIGN
+		   || transferType == TT_FIELDASSIGN) /* evans 2002-02-05 - added TT_FIELDASSIGN */
 	    {
 	      ; /* no error */
 	    }
@@ -752,6 +776,7 @@ checkCompletelyDefined (exprNode fexp, /*@exposed@*/ sRef fref, sRef ofref,
       else
 	{
 	  llassert (transferType == TT_DOASSIGN
+		    || transferType == TT_FIELDASSIGN /* evans 2002-02-05: no warnings for local fields */
 		    || transferType == TT_GLOBINIT
 		    || transferType == TT_LEAVETRANS);
 	}
@@ -871,10 +896,8 @@ checkCompletelyDefined (exprNode fexp, /*@exposed@*/ sRef fref, sRef ofref,
 			{
 			  sRef rb = sRef_getRootBase (fref);
 			  sRef_showStateInfo (fref);
-
-			  DPRINTF (("fref: %s", sRef_unparseFull (fref)));
-			  DPRINTF (("rb: %s", sRef_unparseFull (rb)));
-			  sRef_setDefinedComplete (rb, loc);
+			  
+			  sRef_setDefinedCompleteDirect (rb, loc);
 			}
 		    }
 		}
@@ -1196,6 +1219,17 @@ checkCompletelyDefined (exprNode fexp, /*@exposed@*/ sRef fref, sRef ofref,
 				      sRef_unparse (fref)),
 			     loc);
 			}
+		      /* evans 2001-08-21: added this branch for global returns */
+		      else if (transferType == TT_GLOBRETURN)
+			{
+			  voptgenerror 
+			    (FLG_UNIONDEF,
+			     message ("Union %q reachable from global %q has "
+				      "no defined field",
+				      sRef_unparse (fref),
+				      sRef_unparse (sRef_getRootBase (fref))),
+			     loc);
+			}
 		      else if (transferType == TT_DOASSIGN
 			       || transferType == TT_FIELDASSIGN
 			       || transferType == TT_GLOBINIT)
@@ -1254,17 +1288,18 @@ static /*@observer@*/ cstring dscCode_unparse (dscCode desc) /*@*/
 }
 
 static bool 
-  checkCompletelyDestroyed (exprNode p_fexp, sRef p_fref, bool p_topLevel, 
-			    fileloc p_loc, int p_depth, dscCode p_desc,
-			    bool p_hideErrors);
+checkCompletelyDestroyed (exprNode p_fexp, sRef p_fref, bool p_topLevel, bool p_isField,
+			  fileloc p_loc, int p_depth, dscCode p_desc,
+			  bool p_hideErrors);
 
-bool checkGlobalDestroyed (sRef fref, fileloc loc)
+bool transferChecks_globalDestroyed (sRef fref, fileloc loc)
 {
-  return (checkCompletelyDestroyed (exprNode_undefined, fref, TRUE,
+  DPRINTF (("Global destroyed: %s", sRef_unparseFull (fref)));
+  return (checkCompletelyDestroyed (exprNode_undefined, fref, TRUE, FALSE,
 				    loc, 0, DSC_GLOB, FALSE));
 }
 
-void checkLocalDestroyed (sRef fref, fileloc loc)
+void transferChecks_localDestroyed (sRef fref, fileloc loc)
 {
   if (sRef_isObserver (fref) || sRef_isExposed (fref)
       || sRef_isPartial (fref))
@@ -1273,12 +1308,12 @@ void checkLocalDestroyed (sRef fref, fileloc loc)
     }
   else
     {
-      (void) checkCompletelyDestroyed (exprNode_undefined, fref, TRUE,
+      (void) checkCompletelyDestroyed (exprNode_undefined, fref, TRUE, FALSE,
 				       loc, 0, DSC_LOCAL, FALSE);
     }
 }
 
-void checkStructDestroyed (sRef fref, fileloc loc)
+void transferChecks_structDestroyed (sRef fref, fileloc loc)
 {
   DPRINTF (("Check struct destroyed: %s", sRef_unparse (fref)));
 
@@ -1289,19 +1324,21 @@ void checkStructDestroyed (sRef fref, fileloc loc)
     }
   else
     {
-      (void) checkCompletelyDestroyed (exprNode_undefined, fref, TRUE,
+      (void) checkCompletelyDestroyed (exprNode_undefined, fref, TRUE, FALSE,
 				       loc, 0, DSC_STRUCT, FALSE);
     }
 }
 
 static bool
-  checkCompletelyDestroyed (exprNode fexp, sRef fref, bool topLevel,
-			    fileloc loc, int depth,
-			    dscCode desc, bool hideErrors)
+checkCompletelyDestroyed (exprNode fexp, sRef fref, bool topLevel, bool isField,
+			  fileloc loc, int depth,
+			  dscCode desc, bool hideErrors)
 {
   ctype ct;
-
-  DPRINTF (("Check completely destroyed: %s", sRef_unparseFull (fref)));
+  
+  DPRINTF (("Check completely destroyed: %s / %s",
+	    sRef_unparse (fref),
+	    bool_unparse (hideErrors)));
 
   if (depth > MAXDEPTH)
     {
@@ -1357,23 +1394,40 @@ static bool
       }
   }
 
-  if (sRef_isPdefined (fref) && !context_getFlag (FLG_STRICTDESTROY))
+  ct = ctype_realType (sRef_getType (fref));
+
+  if (sRef_isPdefined (fref) 
+      && ctype_isAP (ct)
+      && !isField
+      && !context_getFlag (FLG_STRICTDESTROY))
     {
-      DPRINTF (("Partial: %s", sRef_unparseFull (fref)));
-      hideErrors = TRUE; /* Don't report any more errors, but still change ownership. */
-    }
+      /*
+      ** Don't report errors for array elements (unless strictdestroy)
+      ** when at least one appears to have been destroyed.
+      */
 
+      DPRINTF (("Partial: %s / hiding errors: %s", sRef_unparseFull (fref),
+		ctype_unparse (ct)));
+      hideErrors = TRUE;
+      /* Don't report any more errors, but still change ownership. */
+    }
+  
   if (usymtab_isDefinitelyNull (fref)) 
     {
       DPRINTF (("Probably null!"));
       return TRUE;
     }
 
-  if (!context_getFlag (FLG_COMPDESTROY)) return TRUE;
-  if (!context_getFlag (FLG_MUSTFREE)) return TRUE;
+  /*
+  ** evans 2002-01-02: removed this
+  ** if (!context_flagOn (FLG_COMPDESTROY, loc)) 
+  ** {
+  ** return TRUE;
+  ** }
+  ** 
+  ** if (!context_getFlag (FLG_MUSTFREEONLY)) return TRUE;
+  */
   
-  ct = ctype_realType (sRef_getType (fref));
-
   DPRINTF (("Here: %s", ctype_unparse (ct)));
 
   if (!topLevel)
@@ -1491,7 +1545,7 @@ static bool
 	  return FALSE;
 	}
       
-      if (/*! evs-2001-03-24 sRef_isAnyDefined (fref) || */
+      if (/*! evs-2002-03-24 sRef_isAnyDefined (fref) || */
 	  sRef_isDead (fref)
 	  || (sRef_isPdefined (fref) 
 	      && sRefSet_isEmpty (sRef_derivedFields (fref)))) 
@@ -1511,8 +1565,8 @@ static bool
       sRef fptr = sRef_constructDeadDeref (fref);
       bool res;
 
-      res = checkCompletelyDestroyed (fexp, fptr, FALSE, loc,
-				      depth + 1, desc, hideErrors);
+      res = checkCompletelyDestroyed (fexp, fptr, FALSE, FALSE,
+				      loc, depth + 1, desc, hideErrors);
       
       return res;
     }
@@ -1531,8 +1585,8 @@ static bool
 	{
 	  sRef farr = sRef_constructDeadDeref (fref);
 	  
-	  return (checkCompletelyDestroyed (fexp, farr, FALSE, loc, 
-					    depth + 1, desc, hideErrors));
+	  return (checkCompletelyDestroyed (fexp, farr, FALSE, FALSE,
+					    loc, depth + 1, desc, hideErrors));
 	}
     }
   else if (ctype_isStruct (ct))
@@ -1566,12 +1620,12 @@ static bool
 	      
 	      DPRINTF (("Check field: %s", sRef_unparseFull (field)));
 
-	      isOk = (checkCompletelyDestroyed (fexp, field, FALSE, loc,
-						depth + 1, desc, hideErrors)
+	      isOk = (checkCompletelyDestroyed (fexp, field, FALSE, TRUE,
+						loc, depth + 1, desc, hideErrors)
 		      && isOk);
 	    } end_uentryList_elements;
 	}
-
+      
       return isOk;
     }
   else
@@ -1581,7 +1635,7 @@ static bool
 }
 
 void
-checkReturnTransfer (exprNode fexp, uentry rval)
+transferChecks_return (exprNode fexp, uentry rval)
 {
   sRef uref = uentry_getSref (rval);
   sRef rref = sRef_makeNew (sRef_getType (uref), uref, cstring_undefined);
@@ -1670,7 +1724,8 @@ checkReturnTransfer (exprNode fexp, uentry rval)
 	      DPRINTF (("el: %s / %s", sRef_unparse (el),
 			sRef_unparse (base)));
 	      
-	      if (sRef_isResult (base))
+	      if (sRef_isResult (base) 
+		  && !sRef_isDefinitelyNull (fref)) /* evans 2002-07-22: don't report allocation errors for null results */
 		{
 		  sRef sr = sRef_fixBase (el, fref);
 		  
@@ -1724,6 +1779,7 @@ checkReturnTransfer (exprNode fexp, uentry rval)
     {
       (void) checkTransfer (fexp, exprNode_getSref (fexp),
 			    exprNode_undefined, rref, 
+			    exprNode_undefined,
 			    exprNode_loc (fexp), TT_FCNRETURN);
     }
 }
@@ -1806,8 +1862,8 @@ static void
 */
 
 void
-checkPassTransfer (exprNode fexp, uentry arg, bool isSpec,
-		   /*@dependent@*/ exprNode fcn, int argno, int totargs)
+transferChecks_passParam (exprNode fexp, uentry arg, bool isSpec,
+			  /*@dependent@*/ exprNode fcn, int argno, int totargs)
 {
   sRef tref = uentry_getSref (arg);
   sRef fref = exprNode_getSref (fexp);
@@ -1895,8 +1951,8 @@ checkPassTransfer (exprNode fexp, uentry arg, bool isSpec,
 	    }
 	}
       
-      (void) checkCompletelyDestroyed (fexp, fref, TRUE, exprNode_loc (fexp),
-				       0, DSC_PARAM, FALSE);
+      (void) checkCompletelyDestroyed (fexp, fref, TRUE, FALSE,
+				       exprNode_loc (fexp), 0, DSC_PARAM, FALSE);
 
       /* make it defined now, so checkTransfer is okay */
       sRef_setDefined (fref, exprNode_loc (fexp)); 
@@ -2113,13 +2169,14 @@ checkPassTransfer (exprNode fexp, uentry arg, bool isSpec,
 	
 	{
 	  voptgenerror 
-	    (FLG_MUSTFREE,
+	    (FLG_MUSTFREEFRESH,
 	     message ("New fresh storage %q(type %s) passed as %s (not released): %s",
 		      sRef_unparseOpt (fref),
 		      ctype_unparse (sRef_getType (fref)),
 		      alkind_unparse (sRef_getAliasKind (tref)),
 		      exprNode_unparse (fexp)),
 	     exprNode_loc (fexp));
+
 	  DPRINTF (("Fresh: %s", sRef_unparseFull (fref)));
 	}
       else 
@@ -2131,7 +2188,7 @@ checkPassTransfer (exprNode fexp, uentry arg, bool isSpec,
 	      if (!alkind_isError (ak))
 		{
 		  voptgenerror 
-		    (FLG_MUSTFREE,
+		    (FLG_MUSTFREEFRESH,
 		     message ("New reference %q(type %s) passed as %s (not released): %s",
 			      sRef_unparseOpt (fref),
 			      ctype_unparse (sRef_getType (fref)),
@@ -2145,6 +2202,7 @@ checkPassTransfer (exprNode fexp, uentry arg, bool isSpec,
   
   (void) checkTransfer (fexp, exprNode_getSref (fexp),
 			exprNode_undefined, tref,
+			fcn,
 			exprNode_loc (fexp), TT_FCNPASS);
 
   setCodePoint ();
@@ -2207,19 +2265,19 @@ checkPassTransfer (exprNode fexp, uentry arg, bool isSpec,
 }
 
 void
-checkGlobReturn (uentry glob)
+transferChecks_globalReturn (uentry glob)
 {
   sRef_protectDerivs ();
   checkGlobTrans (glob, TT_GLOBRETURN);
   sRef_clearProtectDerivs ();
 }
 
-void checkParamReturn (uentry actual)
+void transferChecks_paramReturn (uentry actual)
 {
   checkLeaveTrans (actual, TT_PARAMRETURN);
 }
 
-void checkLoseRef (uentry actual)
+void transferChecks_loseReference (uentry actual)
 {
   checkLeaveTrans (actual, TT_LEAVETRANS);
 }
@@ -2259,8 +2317,11 @@ static void
 checkGlobTrans (uentry glob, transferKind type)
 {
   sRef eref = uentry_getOrigSref (glob);
-  
-  (void) checkCompletelyDefined (exprNode_undefined, uentry_getSref (glob), uentry_getSref (glob),
+ 
+  DPRINTF (("Completely defined: %s", uentry_unparseFull (glob)));
+
+  (void) checkCompletelyDefined (exprNode_undefined, uentry_getSref (glob), 
+				 uentry_getSref (glob),
 				 exprNode_undefined, eref, 
 				 TRUE, FALSE, FALSE,
 				 g_currentloc, type, 0, TRUE);
@@ -2319,6 +2380,7 @@ static void checkStructTransfer (exprNode lhs, sRef slhs, exprNode rhs, sRef srh
 			  sRef lfld = sRef_makeField (slhs, fieldname);
 
 			  (void) checkTransfer (rhs, sr, lhs, lfld, 
+						exprNode_undefined,
 						exprNode_loc (lhs), tt);
 			}
 		    } end_sRefSet_realElements ;
@@ -2331,7 +2393,9 @@ static void checkStructTransfer (exprNode lhs, sRef slhs, exprNode rhs, sRef srh
 		    {
 		      sRef rfld = sRef_makeField (srhs, uentry_rawName (field));
 		      sRef lfld = sRef_makeField (slhs, uentry_rawName (field));
-		      (void) checkTransfer (rhs, rfld, lhs, lfld, exprNode_loc (lhs), tt);
+		      (void) checkTransfer (rhs, rfld, lhs, lfld, 
+					    exprNode_undefined,
+					    exprNode_loc (lhs), tt);
 		    } end_uentryList_elements ;
 		}
 
@@ -2345,23 +2409,25 @@ static void checkStructTransfer (exprNode lhs, sRef slhs, exprNode rhs, sRef srh
 }
 
 void
-checkInitTransfer (exprNode lhs, exprNode rhs)
+transferChecks_initialization (exprNode lhs, exprNode rhs)
 {
   sRef slhs = exprNode_getSref (lhs);
   
   if (sRef_isFileOrGlobalScope (slhs) || (!sRef_isCvar (slhs)))
     {
       (void) checkTransfer (rhs, exprNode_getSref (rhs), 
-			    lhs, slhs, exprNode_loc (rhs), TT_GLOBINIT);
+			    lhs, slhs, 
+			    exprNode_undefined,
+			    exprNode_loc (rhs), TT_GLOBINIT);
     }
   else
     {
-      checkAssignTransfer (lhs, rhs);
+      transferChecks_assign (lhs, rhs);
     }
 }
 
 void
-checkAssignTransfer (exprNode lhs, exprNode rhs)
+transferChecks_assign (exprNode lhs, exprNode rhs)
 {
   sRef slhs = exprNode_getSref (lhs);
   sRef srhs = exprNode_getSref (rhs);
@@ -2382,6 +2448,7 @@ checkAssignTransfer (exprNode lhs, exprNode rhs)
       DPRINTF (("lhs: %s", sRef_unparseFull (slhs)));
       DPRINTF (("rhs: %s", sRef_unparseFull (srhs)));
       (void) checkTransfer (rhs, srhs, lhs, slhs, 
+			    exprNode_undefined,
 			    exprNode_loc (lhs), TT_DOASSIGN);
       DPRINTF (("lhs: %s", sRef_unparseFull (slhs)));
       DPRINTF (("rhs: %s", sRef_unparseFull (srhs)));
@@ -2550,83 +2617,82 @@ checkTransferAssignAux (sRef fref, exprNode fexp, /*@unused@*/ bool ffix,
       && !(sRef_same (fref, tref)) /* okay to assign to self (returned params) */
       && !(usymtab_isDefinitelyNull (tref))) 
     {
-      if (context_getFlag (FLG_MUSTFREE))
+      if (transferChecks_canLoseReference (tref, loc))
 	{
-	  if (canLoseReference (tref, loc))
+	  ; /* no error */
+	}
+      else
+	{
+	  flagcode flg = sRef_isFresh (tref) ? FLG_MUSTFREEFRESH : FLG_MUSTFREEONLY;
+
+	  if (sRef_hasLastReference (tref))
 	    {
-	      ; /* no error */
+	      if (optgenerror 
+		  (flg,
+		   message ("Last reference %q to %s storage %q(type %s) not released "
+			    "before assignment: %q",
+			    sRef_unparse (tref),
+			    alkind_unparse (tkind),
+			    sRef_unparseOpt (sRef_getAliasInfoRef (tref)),
+			    ctype_unparse (sRef_getType (tref)),
+			    generateText (fexp, texp, tref, transferType)),
+		   loc))
+		{
+		  sRef_showRefLost (tref);
+		}
 	    }
 	  else
 	    {
-	      if (sRef_hasLastReference (tref))
+	      if (context_inGlobalScope ())
 		{
-		  if (optgenerror 
-		      (FLG_MUSTFREE,
-		       message ("Last reference %q to %s storage %q(type %s) not released "
-				"before assignment: %q",
-				sRef_unparse (tref),
-				alkind_unparse (tkind),
-				sRef_unparseOpt (sRef_getAliasInfoRef (tref)),
-				ctype_unparse (sRef_getType (tref)),
-				generateText (fexp, texp, tref, transferType)),
-		       loc))
-		    {
-		      sRef_showRefLost (tref);
-		    }
+		  /* no errors for static initializations */
 		}
-	      else
+	      else 
 		{
-		  if (context_inGlobalScope ())
-		    {
-		      /* no errors for static initializations */
-		    }
-		  else 
+		  /*
+		  ** don't report this error for a[i], since it could
+		  ** be a new element.
+		  */
+		  
+		  if (alkind_isNewRef (tkind))
 		    {
-		      /*
-		       ** don't report this error for a[i], since it could
-		       ** be a new element.
-		       */
-		      
-		      if (alkind_isNewRef (tkind))
-			{
-			  if (optgenerror 
-			      (FLG_MUSTFREE,
-			       message 
-			       ("%q %q(type %s) not released before assignment: %q",
-				cstring_makeLiteral
-				(alkind_isKillRef (sRef_getOrigAliasKind (tref))
-				 ? "Kill reference parameter" : "New reference"),
-				sRef_unparseOpt (tref),
-				ctype_unparse (sRef_getType (tref)),
-				generateText (fexp, texp, tref, transferType)),
-			       loc))
-			    {
-			      sRef_showAliasInfo (tref);
-			      sRef_setAliasKind (tref, AK_ERROR, loc);
-			    }
-			}
-		      else if
-			(!(sRef_isUnknownArrayFetch (tref)
-			   && !context_getFlag (FLG_STRICTDESTROY))
-			 && !sRef_isUnionField (tref)
-			 && !sRef_isRelDef (tref)
-			 && optgenerror 
-			 (FLG_MUSTFREE,
-			  message 
-			  ("%s storage %q(type %s) not released before assignment: %q",
-			   alkind_capName (tkind),
-			   sRef_unparseOpt (tref),
-			   ctype_unparse (sRef_getType (tref)),
-			   generateText (fexp, texp, tref, transferType)),
-			  loc))
-			  {
-			    sRef_showAliasInfo (tref);
-			  }
-		      else
+		      if (optgenerror 
+			  (flg,
+			   message 
+			   ("%q %q(type %s) not released before assignment: %q",
+			    cstring_makeLiteral
+			    (alkind_isKillRef (sRef_getOrigAliasKind (tref))
+			     ? "Kill reference parameter" : "New reference"),
+			    sRef_unparseOpt (tref),
+			    ctype_unparse (sRef_getType (tref)),
+			    generateText (fexp, texp, tref, transferType)),
+			   loc))
 			{
-			  ;
+			  sRef_showAliasInfo (tref);
+			  sRef_setAliasKind (tref, AK_ERROR, loc);
 			}
 		    }
+		  else if
+		    (!(sRef_isUnknownArrayFetch (tref)
+		       && !context_getFlag (FLG_STRICTDESTROY))
+		     && !sRef_isUnionField (tref)
+		     && !sRef_isRelDef (tref)
+		     && optgenerror 
+		     (flg,
+		      message 
+		      ("%s storage %q(type %s) not released before assignment: %q",
+		       alkind_capName (tkind),
+		       sRef_unparseOpt (tref),
+		       ctype_unparse (sRef_getType (tref)),
+		       generateText (fexp, texp, tref, transferType)),
+		      loc))
+		    {
+		      sRef_showAliasInfo (tref);
+		    }
+		  else
+		    {
+		      ;
+		    }
 		}
 	    }
 	}
@@ -3284,7 +3350,9 @@ checkTransferExposure (sRef fref, exprNode fexp, /*@unused@*/ bool ffix,
 	      ;
 	    }
 	}
-      else if (transferType == TT_DOASSIGN)
+      else if (transferType == TT_DOASSIGN
+	       /* evans 2001-10-05: added TT_FIELDASSIGN: */
+	       || transferType == TT_FIELDASSIGN)
 	{
 	  if (!(sRef_isExposed (tref) 
 		|| !sRef_isCvar (tref)
@@ -3831,7 +3899,7 @@ checkTransferAux (exprNode fexp, /*@exposed@*/ sRef fref, bool ffix,
 	      && ctype_isMutable (exprNode_getType (fexp))
 	      && (!iseitherassign || sRef_isReference (tref)))
 	    {
-	      if (canLoseReference (fref, loc))
+	      if (transferChecks_canLoseReference (fref, loc))
 		{
 		  ;
 		}
@@ -3964,36 +4032,102 @@ checkMetaStateConsistent (/*@exposed@*/ sRef fref, sRef tref,
 	  {
 	    ;
 	  }
-	else if (!stateValue_sameValue (fval, tval))
+	else if (sRef_isDefinitelyNull (fref)
+		 || usymtab_isDefinitelyNull (fref))
 	  {
-	    DPRINTF (("Check: %s / %s / %s / %s", fkey,
-		      metaStateInfo_unparse (minfo),
-		      stateValue_unparse (fval),
-		      stateValue_unparse (tval)));
+	    ; /* No errors for null values in state transfers. */
+	  }
+	
+	else
+	  {
+	    stateCombinationTable sctable = metaStateInfo_getTransferTable (minfo);
+	    cstring msg = cstring_undefined;
+	    int nval = stateCombinationTable_lookup (sctable, 
+						     stateValue_getValue (fval), 
+						     stateValue_getValue (tval), 
+						     &msg);
 	    
-	    if (sRef_isDefinitelyNull (fref)
-		|| usymtab_isDefinitelyNull (fref))
-	      {
-		; /* No errors for null values in state transfers. */
-	      }
-	    else
+	    if (nval == stateValue_error)
 	      {
-		if (optgenerror 
-		    (FLG_STATETRANSFER,
-		     message
-		     ("Invalid transfer from %q %x to %q",
-		      stateValue_unparseValue (fval, minfo),
-		      sRef_unparse (fref),
-		      stateValue_unparseValue (tval, minfo)),
-		     loc))
+		if (transferType == TT_LEAVETRANS)
+		  {
+		    BADBRANCH;
+		  }
+		else if (transferType == TT_GLOBRETURN)
 		  {
-		    sRef_showMetaStateInfo (fref, fkey);
+		    if (optgenerror 
+			(FLG_STATETRANSFER,
+			 message
+			 ("Function returns with global %q in inconsistent state (%q is %q, should be %q)%q",
+			  sRef_unparse (sRef_getRootBase (fref)),
+			  sRef_unparse (fref),
+			  stateValue_unparseValue (fval, minfo),
+			  stateValue_unparseValue (tval, minfo),
+			  cstring_isDefined (msg) 
+			  ? message (": %s", msg) : cstring_undefined),
+			 loc))
+		      {
+			sRef_showMetaStateInfo (fref, fkey);
+		      }		    
 		  }
+		else if (transferType == TT_GLOBPASS)
+		  {
+		    if (optgenerror 
+			(FLG_STATETRANSFER,
+			 message
+			 ("Function called with global %q in inconsistent state (%q is %q, should be %q)%q",
+			  sRef_unparse (sRef_getRootBase (fref)),
+			  stateValue_unparseValue (fval, minfo),
+			  sRef_unparse (fref),
+			  stateValue_unparseValue (tval, minfo),
+			  cstring_isDefined (msg) 
+			  ? message (": %s", msg) : cstring_undefined),
+			 loc))
+		      {
+			sRef_showMetaStateInfo (fref, fkey);
+		      }		    
+		  }
+		else if (transferType == TT_PARAMRETURN)
+		  {
+		    if (optgenerror 
+			(FLG_STATETRANSFER,
+			 message
+			 ("Function returns with parameter %q in inconsistent state (%q is %q, should be %q)%q",
+			  sRef_unparse (sRef_getRootBase (fref)),
+			  sRef_unparse (fref),			
+			  stateValue_unparseValue (fval, minfo),
+			  stateValue_unparseValue (tval, minfo),
+			  cstring_isDefined (msg) 
+			  ? message (": %s", msg) : cstring_undefined),
+			 loc))
+		      {
+			sRef_showMetaStateInfo (fref, fkey);
+		      }
+		  }
+		else
+		  {
+		    if (optgenerror 
+			(FLG_STATETRANSFER,
+			 message
+			 ("Invalid transfer from %q %x to %q (%q)%q",
+			  stateValue_unparseValue (fval, minfo),
+			  sRef_unparse (fref),
+			  stateValue_unparseValue (tval, minfo),
+			  sRef_unparse (tref),
+			  cstring_isDefined (msg) 
+			  ? message (": %s", msg) : cstring_undefined),
+			 loc))
+		      {
+			sRef_showMetaStateInfo (fref, fkey);
+		      }
+		  }
+
+	      }
+	    	    
+	    if (stateValue_getValue (fval) != nval)
+	      {
+		stateValue_updateValueLoc (fval, nval, loc);
 	      }
-	  }
-	else
-	  {
-	    ; /* Match okay */
 	  }
       }
     
@@ -4004,6 +4138,7 @@ checkMetaStateConsistent (/*@exposed@*/ sRef fref, sRef tref,
 
 static void
 checkMetaStateTransfer (exprNode fexp, sRef fref, exprNode texp, sRef tref, 
+			exprNode fcn,
 			fileloc loc, transferKind /*@i32@*/ transferType)
 {
   valueTable fvalues = sRef_getValueTable (fref);
@@ -4100,22 +4235,24 @@ checkMetaStateTransfer (exprNode fexp, sRef fref, exprNode texp, sRef tref,
 	      }
 	    else
 	      {
-		if (cstring_isDefined (msg)) 
+		if (nval == stateValue_error)
 		  {
 		    /*@i32 print extra info for assignments@*/
 		    
 		    if (optgenerror 
 			(FLG_STATETRANSFER,
 			 message
-			 ("Invalid transfer from %q %x to %q (%s): %q",
+			 ("Invalid transfer from %q %x to %q%q: %q",
 			  stateValue_unparseValue (fval, minfo),
 			  sRef_unparse (fref),
 			  stateValue_unparseValue (tval, minfo),
-			  msg,
-			  transferErrorExcerpt (transferType, fexp, texp)),
+			  cstring_isDefined (msg) 
+			  ? message (" (%s)", msg) : cstring_undefined,
+			  transferErrorExcerpt (transferType, fexp, texp, fcn)),
 			 loc))
 		      {
 			sRef_showMetaStateInfo (fref, fkey);
+			sRef_showMetaStateInfo (tref, fkey);
 		      }
 		    else
 		      {
@@ -4160,6 +4297,7 @@ checkMetaStateTransfer (exprNode fexp, sRef fref, exprNode texp, sRef tref,
 static void
 checkTransfer (exprNode fexp, /*@dependent@*/ sRef fref, 
 	       exprNode texp, /*@dependent@*/ sRef tref, 
+	       exprNode fcn,
 	       fileloc loc, transferKind transferType)
 {
   setCodePoint ();
@@ -4176,7 +4314,8 @@ checkTransfer (exprNode fexp, /*@dependent@*/ sRef fref,
 	    exprNode_unparse (fexp),
 	    exprNode_unparse (texp)));
 
-  checkMetaStateTransfer (fexp, fref, texp, tref, loc, transferType);
+  checkMetaStateTransfer (fexp, fref, texp, tref, fcn,
+			  loc, transferType);
 
   /*
   ** for local references, we need to check
@@ -4307,7 +4446,7 @@ static /*@exposed@*/ sRef
   return sRef_undefined;
 }
 
-bool canLoseReference (/*@dependent@*/ sRef sr, fileloc loc)
+bool transferChecks_canLoseReference (/*@dependent@*/ sRef sr, fileloc loc)
 {
   bool gotone = FALSE;
   sRefSet ab = usymtab_aliasedBy (sr); /* yes, really mean aliasedBy */