Phase 2 of read-only-plans project: restructure expression-tree nodes

so that all executable expression nodes inherit from a common supertype
Expr.  This is somewhat of an exercise in code purity rather than any
real functional advance, but getting rid of the extra Oper or Func node
formerly used in each operator or function call should provide at least
a little space and speed improvement.
initdb forced by changes in stored-rules representation.

src/backend/optimizer/prep/prepqual.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/optimizer/prep/prepqual.c,v 1.33 2002/09/02 02:47:02 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/optimizer/prep/prepqual.c,v 1.34 2002/12/12 15:49:32 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -294,7 +294,7 @@ flatten_andors(Expr *qual)
 		List	   *out_list = NIL;
 		List	   *arg;
 
-		foreach(arg, qual->args)
+		foreach(arg, ((BoolExpr *) qual)->args)
 		{
 			Expr	   *subexpr = flatten_andors((Expr *) lfirst(arg));
 
@@ -305,7 +305,7 @@ flatten_andors(Expr *qual)
 			 * with any other expr. Otherwise we'd need a listCopy here.
 			 */
 			if (and_clause((Node *) subexpr))
-				out_list = nconc(out_list, subexpr->args);
+				out_list = nconc(out_list, ((BoolExpr *) subexpr)->args);
 			else
 				out_list = lappend(out_list, subexpr);
 		}
@@ -316,7 +316,7 @@ flatten_andors(Expr *qual)
 		List	   *out_list = NIL;
 		List	   *arg;
 
-		foreach(arg, qual->args)
+		foreach(arg, ((BoolExpr *) qual)->args)
 		{
 			Expr	   *subexpr = flatten_andors((Expr *) lfirst(arg));
 
@@ -327,7 +327,7 @@ flatten_andors(Expr *qual)
 			 * with any other expr. Otherwise we'd need a listCopy here.
 			 */
 			if (or_clause((Node *) subexpr))
-				out_list = nconc(out_list, subexpr->args);
+				out_list = nconc(out_list, ((BoolExpr *) subexpr)->args);
 			else
 				out_list = lappend(out_list, subexpr);
 		}
@@ -335,20 +335,17 @@ flatten_andors(Expr *qual)
 	}
 	else if (not_clause((Node *) qual))
 		return make_notclause(flatten_andors(get_notclausearg(qual)));
-	else if (is_opclause((Node *) qual))
+	else if (is_opclause(qual))
 	{
+		OpExpr	   *opexpr = (OpExpr *) qual;
 		Expr	   *left = (Expr *) get_leftop(qual);
 		Expr	   *right = (Expr *) get_rightop(qual);
 
-		if (right)
-			return make_clause(qual->opType, qual->oper,
-							   lcons(flatten_andors(left),
-									 lcons(flatten_andors(right),
-										   NIL)));
-		else
-			return make_clause(qual->opType, qual->oper,
-							   lcons(flatten_andors(left),
-									 NIL));
+		return make_opclause(opexpr->opno,
+							 opexpr->opresulttype,
+							 opexpr->opretset,
+							 flatten_andors(left),
+							 flatten_andors(right));
 	}
 	else
 		return qual;
@@ -379,7 +376,8 @@ pull_ors(List *orlist)
 		 * we'd need a listCopy here.
 		 */
 		if (or_clause((Node *) subexpr))
-			out_list = nconc(out_list, pull_ors(subexpr->args));
+			out_list = nconc(out_list,
+							 pull_ors(((BoolExpr *) subexpr)->args));
 		else
 			out_list = lappend(out_list, subexpr);
 	}
@@ -410,7 +408,8 @@ pull_ands(List *andlist)
 		 * we'd need a listCopy here.
 		 */
 		if (and_clause((Node *) subexpr))
-			out_list = nconc(out_list, pull_ands(subexpr->args));
+			out_list = nconc(out_list,
+							 pull_ands(((BoolExpr *) subexpr)->args));
 		else
 			out_list = lappend(out_list, subexpr);
 	}
@@ -433,20 +432,17 @@ find_nots(Expr *qual)
 
 #ifdef NOT_USED
 	/* recursing into operator expressions is probably not worth it. */
-	if (is_opclause((Node *) qual))
+	if (is_opclause(qual))
 	{
+		OpExpr	   *opexpr = (OpExpr *) qual;
 		Expr	   *left = (Expr *) get_leftop(qual);
 		Expr	   *right = (Expr *) get_rightop(qual);
 
-		if (right)
-			return make_clause(qual->opType, qual->oper,
-							   lcons(find_nots(left),
-									 lcons(find_nots(right),
-										   NIL)));
-		else
-			return make_clause(qual->opType, qual->oper,
-							   lcons(find_nots(left),
-									 NIL));
+		return make_opclause(opexpr->opno,
+							 opexpr->opresulttype,
+							 opexpr->opretset,
+							 find_nots(left),
+							 find_nots(right));
 	}
 #endif
 	if (and_clause((Node *) qual))
@@ -454,7 +450,7 @@ find_nots(Expr *qual)
 		List	   *t_list = NIL;
 		List	   *temp;
 
-		foreach(temp, qual->args)
+		foreach(temp, ((BoolExpr *) qual)->args)
 			t_list = lappend(t_list, find_nots(lfirst(temp)));
 		return make_andclause(pull_ands(t_list));
 	}
@@ -463,7 +459,7 @@ find_nots(Expr *qual)
 		List	   *t_list = NIL;
 		List	   *temp;
 
-		foreach(temp, qual->args)
+		foreach(temp, ((BoolExpr *) qual)->args)
 			t_list = lappend(t_list, find_nots(lfirst(temp)));
 		return make_orclause(pull_ors(t_list));
 	}
@@ -492,20 +488,17 @@ push_nots(Expr *qual)
 	 * Otherwise, retain the clause as it is (the 'not' can't be pushed
 	 * down any farther).
 	 */
-	if (is_opclause((Node *) qual))
+	if (is_opclause(qual))
 	{
-		Oper	   *oper = (Oper *) ((Expr *) qual)->oper;
-		Oid			negator = get_negator(oper->opno);
+		OpExpr	   *opexpr = (OpExpr *) qual;
+		Oid			negator = get_negator(opexpr->opno);
 
 		if (negator)
-		{
-			Oper	   *op = (Oper *) makeOper(negator,
-											   InvalidOid,
-											   oper->opresulttype,
-											   oper->opretset);
-
-			return make_opclause(op, get_leftop(qual), get_rightop(qual));
-		}
+			return make_opclause(negator,
+								 opexpr->opresulttype,
+								 opexpr->opretset,
+								 (Expr *) get_leftop(qual),
+								 (Expr *) get_rightop(qual));
 		else
 			return make_notclause(qual);
 	}
@@ -521,7 +514,7 @@ push_nots(Expr *qual)
 		List	   *t_list = NIL;
 		List	   *temp;
 
-		foreach(temp, qual->args)
+		foreach(temp, ((BoolExpr *) qual)->args)
 			t_list = lappend(t_list, push_nots(lfirst(temp)));
 		return make_orclause(pull_ors(t_list));
 	}
@@ -530,7 +523,7 @@ push_nots(Expr *qual)
 		List	   *t_list = NIL;
 		List	   *temp;
 
-		foreach(temp, qual->args)
+		foreach(temp, ((BoolExpr *) qual)->args)
 			t_list = lappend(t_list, push_nots(lfirst(temp)));
 		return make_andclause(pull_ands(t_list));
 	}
@@ -576,7 +569,7 @@ find_ors(Expr *qual)
 		List	   *andlist = NIL;
 		List	   *temp;
 
-		foreach(temp, qual->args)
+		foreach(temp, ((BoolExpr *) qual)->args)
 			andlist = lappend(andlist, find_ors(lfirst(temp)));
 		return make_andclause(pull_ands(andlist));
 	}
@@ -585,7 +578,7 @@ find_ors(Expr *qual)
 		List	   *orlist = NIL;
 		List	   *temp;
 
-		foreach(temp, qual->args)
+		foreach(temp, ((BoolExpr *) qual)->args)
 			orlist = lappend(orlist, find_ors(lfirst(temp)));
 		return or_normalize(pull_ors(orlist));
 	}
@@ -629,7 +622,7 @@ or_normalize(List *orlist)
 
 		if (and_clause((Node *) clause))
 		{
-			int			nclauses = length(clause->args);
+			int			nclauses = length(((BoolExpr *) clause)->args);
 
 			if (nclauses > num_subclauses)
 			{
@@ -650,7 +643,7 @@ or_normalize(List *orlist)
 	 */
 	orlist = lremove(distributable, orlist);
 
-	foreach(temp, distributable->args)
+	foreach(temp, ((BoolExpr *) distributable)->args)
 	{
 		Expr	   *andclause = lfirst(temp);
 		List	   *neworlist;
@@ -703,7 +696,7 @@ find_ands(Expr *qual)
 		List	   *orlist = NIL;
 		List	   *temp;
 
-		foreach(temp, qual->args)
+		foreach(temp, ((BoolExpr *) qual)->args)
 			orlist = lappend(orlist, find_ands(lfirst(temp)));
 		return make_orclause(pull_ors(orlist));
 	}
@@ -712,7 +705,7 @@ find_ands(Expr *qual)
 		List	   *andlist = NIL;
 		List	   *temp;
 
-		foreach(temp, qual->args)
+		foreach(temp, ((BoolExpr *) qual)->args)
 			andlist = lappend(andlist, find_ands(lfirst(temp)));
 		return and_normalize(pull_ands(andlist));
 	}
@@ -757,7 +750,7 @@ and_normalize(List *andlist)
 
 		if (or_clause((Node *) clause))
 		{
-			int			nclauses = length(clause->args);
+			int			nclauses = length(((BoolExpr *) clause)->args);
 
 			if (nclauses > num_subclauses)
 			{
@@ -778,7 +771,7 @@ and_normalize(List *andlist)
 	 */
 	andlist = lremove(distributable, andlist);
 
-	foreach(temp, distributable->args)
+	foreach(temp, ((BoolExpr *) distributable)->args)
 	{
 		Expr	   *orclause = lfirst(temp);
 		List	   *newandlist;
@@ -829,7 +822,7 @@ qual_cleanup(Expr *qual)
 		List	   *andlist = NIL;
 		List	   *temp;
 
-		foreach(temp, qual->args)
+		foreach(temp, ((BoolExpr *) qual)->args)
 			andlist = lappend(andlist, qual_cleanup(lfirst(temp)));
 
 		andlist = remove_duplicates(pull_ands(andlist));
@@ -844,7 +837,7 @@ qual_cleanup(Expr *qual)
 		List	   *orlist = NIL;
 		List	   *temp;
 
-		foreach(temp, qual->args)
+		foreach(temp, ((BoolExpr *) qual)->args)
 			orlist = lappend(orlist, qual_cleanup(lfirst(temp)));
 
 		orlist = remove_duplicates(pull_ors(orlist));
@@ -910,7 +903,7 @@ count_bool_nodes(Expr *qual,
 		*nodes = *cnfnodes = 0.0;
 		*dnfnodes = 1.0;		/* DNF nodes will be product of sub-counts */
 
-		foreach(temp, qual->args)
+		foreach(temp, ((BoolExpr *) qual)->args)
 		{
 			count_bool_nodes(lfirst(temp),
 							 &subnodes, &subcnfnodes, &subdnfnodes);
@@ -931,7 +924,7 @@ count_bool_nodes(Expr *qual,
 		*nodes = *dnfnodes = 0.0;
 		*cnfnodes = 1.0;		/* CNF nodes will be product of sub-counts */
 
-		foreach(temp, qual->args)
+		foreach(temp, ((BoolExpr *) qual)->args)
 		{
 			count_bool_nodes(lfirst(temp),
 							 &subnodes, &subcnfnodes, &subdnfnodes);

src/backend/optimizer/prep/preptlist.c

@@ -15,7 +15,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/optimizer/prep/preptlist.c,v 1.58 2002/11/25 21:29:40 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/optimizer/prep/preptlist.c,v 1.59 2002/12/12 15:49:32 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -96,7 +96,7 @@ preprocess_targetlist(List *tlist,
 		if (command_type == CMD_DELETE)
 			tlist = listCopy(tlist);
 
-		tlist = lappend(tlist, makeTargetEntry(resdom, (Node *) var));
+		tlist = lappend(tlist, makeTargetEntry(resdom, (Expr *) var));
 	}
 
 	return tlist;
@@ -215,7 +215,7 @@ expand_targetlist(List *tlist, int command_type,
 												 atttypmod,
 									  pstrdup(NameStr(att_tup->attname)),
 												 false),
-									  new_expr);
+									  (Expr *) new_expr);
 		}
 
 		new_tlist = lappend(new_tlist, new_tle);

src/backend/optimizer/prep/prepunion.c

@@ -14,7 +14,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/optimizer/prep/prepunion.c,v 1.81 2002/11/25 21:29:40 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/optimizer/prep/prepunion.c,v 1.82 2002/12/12 15:49:32 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -406,7 +406,7 @@ generate_setop_tlist(List *colTypes, int flag,
 		 * the output tlists of upper-level nodes!
 		 */
 		if (hack_constants && inputtle->expr && IsA(inputtle->expr, Const))
-			expr = inputtle->expr;
+			expr = (Node *) inputtle->expr;
 		else
 			expr = (Node *) makeVar(0,
 									inputtle->resdom->resno,
@@ -430,7 +430,7 @@ generate_setop_tlist(List *colTypes, int flag,
 							colTypmod,
 							pstrdup(reftle->resdom->resname),
 							false);
-		tlist = lappend(tlist, makeTargetEntry(resdom, expr));
+		tlist = lappend(tlist, makeTargetEntry(resdom, (Expr *) expr));
 		input_tlist = lnext(input_tlist);
 		refnames_tlist = lnext(refnames_tlist);
 	}
@@ -449,7 +449,7 @@ generate_setop_tlist(List *colTypes, int flag,
 								  Int32GetDatum(flag),
 								  false,
 								  true);
-		tlist = lappend(tlist, makeTargetEntry(resdom, expr));
+		tlist = lappend(tlist, makeTargetEntry(resdom, (Expr *) expr));
 	}
 
 	return tlist;
@@ -543,7 +543,7 @@ generate_append_tlist(List *colTypes, bool flag,
 							colTypmod,
 							pstrdup(reftle->resdom->resname),
 							false);
-		tlist = lappend(tlist, makeTargetEntry(resdom, expr));
+		tlist = lappend(tlist, makeTargetEntry(resdom, (Expr *) expr));
 		refnames_tlist = lnext(refnames_tlist);
 	}
 
@@ -561,7 +561,7 @@ generate_append_tlist(List *colTypes, bool flag,
 								INT4OID,
 								-1,
 								0);
-		tlist = lappend(tlist, makeTargetEntry(resdom, expr));
+		tlist = lappend(tlist, makeTargetEntry(resdom, (Expr *) expr));
 	}
 
 	pfree(colTypmods);
@@ -872,13 +872,13 @@ adjust_inherited_attrs_mutator(Node *node,
 	 */
 	if (is_subplan(node))
 	{
-		SubPlan    *subplan;
+		SubPlanExpr *subplan;
 
 		/* Copy the node and process subplan args */
 		node = expression_tree_mutator(node, adjust_inherited_attrs_mutator,
 									   (void *) context);
 		/* Make sure we have separate copies of subplan and its rtable */
-		subplan = (SubPlan *) ((Expr *) node)->oper;
+		subplan = (SubPlanExpr *) node;
 		subplan->plan = copyObject(subplan->plan);
 		subplan->rtable = copyObject(subplan->rtable);
 		return node;