Rename ResolveNew() to ReplaceVarsFromTargetList(), and tweak its API.

This function currently lacks the option to throw error if the provided
targetlist doesn't have any matching entry for a Var to be replaced.
Two of the four existing call sites would be better off with an error,
as would the usage in the pending auto-updatable-views patch, so it seems
past time to extend the API to support that.  To do so, replace the "event"
parameter (historically of type CmdType, though it was declared plain int)
with a special-purpose enum type.

It's unclear whether this function might be called by third-party code.
Since many C compilers wouldn't warn about a call site continuing to use
the old calling convention, rename the function to forcibly break any
such code that hasn't been updated.  The old name was none too well chosen
anyhow.

1 files changed, 35 insertions, 30 deletions

diff --git a/src/backend/rewrite/rewriteHandler.c b/src/backend/rewrite/rewriteHandler.c
index 8f75948d0dd..b785c269a03 100644
--- a/src/backend/rewrite/rewriteHandler.c
+++ b/src/backend/rewrite/rewriteHandler.c
@@ -502,25 +502,27 @@ rewriteRuleAction(Query *parsetree,
 	AddQual(sub_action, parsetree->jointree->quals);
 
 	/*
-	 * Rewrite new.attribute w/ right hand side of target-list entry for
+	 * Rewrite new.attribute with right hand side of target-list entry for
 	 * appropriate field name in insert/update.
 	 *
-	 * KLUGE ALERT: since ResolveNew returns a mutated copy, we can't just
-	 * apply it to sub_action; we have to remember to update the sublink
-	 * inside rule_action, too.
+	 * KLUGE ALERT: since ReplaceVarsFromTargetList returns a mutated copy, we
+	 * can't just apply it to sub_action; we have to remember to update the
+	 * sublink inside rule_action, too.
 	 */
 	if ((event == CMD_INSERT || event == CMD_UPDATE) &&
 		sub_action->commandType != CMD_UTILITY)
 	{
-		sub_action = (Query *) ResolveNew((Node *) sub_action,
-										  new_varno,
-										  0,
-										  rt_fetch(new_varno,
-												   sub_action->rtable),
-										  parsetree->targetList,
-										  event,
-										  current_varno,
-										  NULL);
+		sub_action = (Query *)
+			ReplaceVarsFromTargetList((Node *) sub_action,
+									  new_varno,
+									  0,
+									  rt_fetch(new_varno, sub_action->rtable),
+									  parsetree->targetList,
+									  (event == CMD_UPDATE) ?
+									  REPLACEVARS_CHANGE_VARNO :
+									  REPLACEVARS_SUBSTITUTE_NULL,
+									  current_varno,
+									  NULL);
 		if (sub_action_ptr)
 			*sub_action_ptr = sub_action;
 		else
@@ -543,15 +545,15 @@ rewriteRuleAction(Query *parsetree,
 				   errmsg("cannot have RETURNING lists in multiple rules")));
 		*returning_flag = true;
 		rule_action->returningList = (List *)
-			ResolveNew((Node *) parsetree->returningList,
-					   parsetree->resultRelation,
-					   0,
-					   rt_fetch(parsetree->resultRelation,
-								parsetree->rtable),
-					   rule_action->returningList,
-					   CMD_SELECT,
-					   0,
-					   &rule_action->hasSubLinks);
+			ReplaceVarsFromTargetList((Node *) parsetree->returningList,
+									  parsetree->resultRelation,
+									  0,
+									  rt_fetch(parsetree->resultRelation,
+											   parsetree->rtable),
+									  rule_action->returningList,
+									  REPLACEVARS_REPORT_ERROR,
+									  0,
+									  &rule_action->hasSubLinks);
 
 		/*
 		 * There could have been some SubLinks in parsetree's returningList,
@@ -1703,14 +1705,17 @@ CopyAndAddInvertedQual(Query *parsetree,
 	ChangeVarNodes(new_qual, PRS2_OLD_VARNO, rt_index, 0);
 	/* Fix references to NEW */
 	if (event == CMD_INSERT || event == CMD_UPDATE)
-		new_qual = ResolveNew(new_qual,
-							  PRS2_NEW_VARNO,
-							  0,
-							  rt_fetch(rt_index, parsetree->rtable),
-							  parsetree->targetList,
-							  event,
-							  rt_index,
-							  &parsetree->hasSubLinks);
+		new_qual = ReplaceVarsFromTargetList(new_qual,
+											 PRS2_NEW_VARNO,
+											 0,
+											 rt_fetch(rt_index,
+													  parsetree->rtable),
+											 parsetree->targetList,
+											 (event == CMD_UPDATE) ?
+											 REPLACEVARS_CHANGE_VARNO :
+											 REPLACEVARS_SUBSTITUTE_NULL,
+											 rt_index,
+											 &parsetree->hasSubLinks);
 	/* And attach the fixed qual */
 	AddInvertedQual(parsetree, new_qual);