Improve node type forward reference

petere · petere · commit eafda78fc404 · 2024-10-17T08:36:48.000+02:00
Instead of using Node *, we can use an incomplete struct. That way, everything has the correct type and fewer casts are required. This technique is already used elsewhere in node type definitions. Reviewed-by: Nathan Bossart <nathandbossart@gmail.com> Reviewed-by: Tender Wang <tndrwang@gmail.com> Discussion: https://www.postgresql.org/message-id/flat/637eeea8-5663-460b-a114-39572c0f6c6e%40eisentraut.org
diff --git a/src/backend/commands/createas.c b/src/backend/commands/createas.c
@@ -133,7 +133,7 @@ create_ctas_internal(List *attrList, IntoClause *into)
 	if (is_matview)
 	{
 		/* StoreViewQuery scribbles on tree, so make a copy */
-		Query	   *query = (Query *) copyObject(into->viewQuery);
+		Query	   *query = copyObject(into->viewQuery);
 
 		StoreViewQuery(intoRelationAddr.objectId, query, false);
 		CommandCounterIncrement();
diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c
@@ -3077,7 +3077,7 @@ transformCreateTableAsStmt(ParseState *pstate, CreateTableAsStmt *stmt)
 		 * in the IntoClause because that's where intorel_startup() can
 		 * conveniently get it from.
 		 */
-		stmt->into->viewQuery = (Node *) copyObject(query);
+		stmt->into->viewQuery = copyObject(query);
 	}
 
 	/* represent the command as a utility Query */
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
@@ -152,8 +152,8 @@ typedef struct TableFunc
  * For CREATE MATERIALIZED VIEW, viewQuery is the parsed-but-not-rewritten
  * SELECT Query for the view; otherwise it's NULL.  This is irrelevant in
  * the query jumbling as CreateTableAsStmt already includes a reference to
- * its own Query, so ignore it.  (Although it's actually Query*, we declare
- * it as Node* to avoid a forward reference.)
+ * its own Query, so ignore it.  (We declare it as struct Query* to avoid a
+ * forward reference.)
  */
 typedef struct IntoClause
 {
@@ -166,7 +166,7 @@ typedef struct IntoClause
 	OnCommitAction onCommit;	/* what do we do at COMMIT? */
 	char	   *tableSpaceName; /* table space to use, or NULL */
 	/* materialized view's SELECT query */
-	Node	   *viewQuery pg_node_attr(query_jumble_ignore);
+	struct Query *viewQuery pg_node_attr(query_jumble_ignore);
 	bool		skipData;		/* true for WITH NO DATA */
 } IntoClause;
 

Original file line number	Diff line number	Diff line change
`@@ -133,7 +133,7 @@ create_ctas_internal(List attrList, IntoClause into)`
`133`	`133`	`if (is_matview)`
`134`	`134`	`{`
`135`	`135`	`/* StoreViewQuery scribbles on tree, so make a copy */`
`136`		`- Query query = (Query ) copyObject(into->viewQuery);`
	`136`	`+ Query *query = copyObject(into->viewQuery);`
`137`	`137`
`138`	`138`	`StoreViewQuery(intoRelationAddr.objectId, query, false);`
`139`	`139`	`CommandCounterIncrement();`
Original file line number	Diff line number	Diff line change
`@@ -3077,7 +3077,7 @@ transformCreateTableAsStmt(ParseState pstate, CreateTableAsStmt stmt)`
`3077`	`3077`	`* in the IntoClause because that's where intorel_startup() can`
`3078`	`3078`	`* conveniently get it from.`
`3079`	`3079`	`*/`
`3080`		`- stmt->into->viewQuery = (Node *) copyObject(query);`
	`3080`	`+ stmt->into->viewQuery = copyObject(query);`
`3081`	`3081`	`}`
`3082`	`3082`
`3083`	`3083`	`/* represent the command as a utility Query */`