1 files changed, 87 insertions, 0 deletions
diff --git a/src/backend/nodes/makefuncs.c b/src/backend/nodes/makefuncs.c
index ee15695b914..4b268f3c6b3 100644
--- a/src/backend/nodes/makefuncs.c
+++ b/src/backend/nodes/makefuncs.c
@@ -108,6 +108,93 @@ makeVarFromTargetEntry(Index varno,
 }
 
 /*
+ * makeWholeRowVar -
+ *	  creates a Var node representing a whole row of the specified RTE
+ *
+ * A whole-row reference is a Var with varno set to the correct range
+ * table entry, and varattno == 0 to signal that it references the whole
+ * tuple.  (Use of zero here is unclean, since it could easily be confused
+ * with error cases, but it's not worth changing now.)  The vartype indicates
+ * a rowtype; either a named composite type, or RECORD.  This function
+ * encapsulates the logic for determining the correct rowtype OID to use.
+ */
+Var *
+makeWholeRowVar(RangeTblEntry *rte,
+				Index varno,
+				Index varlevelsup)
+{
+	Var		   *result;
+	Oid			toid;
+
+	switch (rte->rtekind)
+	{
+		case RTE_RELATION:
+			/* relation: the rowtype is a named composite type */
+			toid = get_rel_type_id(rte->relid);
+			if (!OidIsValid(toid))
+				elog(ERROR, "could not find type OID for relation %u",
+					 rte->relid);
+			result = makeVar(varno,
+							 InvalidAttrNumber,
+							 toid,
+							 -1,
+							 varlevelsup);
+			break;
+		case RTE_FUNCTION:
+			toid = exprType(rte->funcexpr);
+			if (type_is_rowtype(toid))
+			{
+				/* func returns composite; same as relation case */
+				result = makeVar(varno,
+								 InvalidAttrNumber,
+								 toid,
+								 -1,
+								 varlevelsup);
+			}
+			else
+			{
+				/*
+				 * func returns scalar; instead of making a whole-row Var,
+				 * just reference the function's scalar output.  (XXX this
+				 * seems a tad inconsistent, especially if "f.*" was
+				 * explicitly written ...)
+				 */
+				result = makeVar(varno,
+								 1,
+								 toid,
+								 -1,
+								 varlevelsup);
+			}
+			break;
+		case RTE_VALUES:
+			toid = RECORDOID;
+			/* returns composite; same as relation case */
+			result = makeVar(varno,
+							 InvalidAttrNumber,
+							 toid,
+							 -1,
+							 varlevelsup);
+			break;
+		default:
+
+			/*
+			 * RTE is a join or subselect.	We represent this as a whole-row
+			 * Var of RECORD type.	(Note that in most cases the Var will be
+			 * expanded to a RowExpr during planning, but that is not our
+			 * concern here.)
+			 */
+			result = makeVar(varno,
+							 InvalidAttrNumber,
+							 RECORDOID,
+							 -1,
+							 varlevelsup);
+			break;
+	}
+
+	return result;
+}
+
+/*
  * makeTargetEntry -
  *	  creates a TargetEntry node
  */