Remove objname/objargs split for referring to objects

In simpler times, it might have worked to refer to all kinds of objects
by a list of name components and an optional argument list.  But this
doesn't work for all objects, which has resulted in a collection of
hacks to place various other nodes types into these fields, which have
to be unpacked at the other end.  This makes it also weird to represent
lists of such things in the grammar, because they would have to be lists
of singleton lists, to make the unpacking work consistently.  The other
problem is that keeping separate name and args fields makes it awkward
to deal with lists of functions.

Change that by dropping the objargs field and have objname, renamed to
object, be a generic Node, which can then be flexibly assigned and
managed using the normal Node mechanisms.  In many cases it will still
be a List of names, in some cases it will be a string Value, for types
it will be the existing Typename, for functions it will now use the
existing ObjectWithArgs node type.  Some of the more obscure object
types still use somewhat arbitrary nested lists.

Reviewed-by: Jim Nasby <Jim.Nasby@BlueTreble.com>
Reviewed-by: Michael Paquier <michael.paquier@gmail.com>

src/include/nodes/parsenodes.h

@@ -2076,8 +2076,7 @@ typedef struct AlterExtensionContentsStmt
 	char	   *extname;		/* Extension's name */
 	int			action;			/* +1 = add object, -1 = drop object */
 	ObjectType	objtype;		/* Object's type */
-	List	   *objname;		/* Qualified name of the object */
-	List	   *objargs;		/* Arguments if needed (eg, for functions) */
+	Node	   *object;			/* Qualified name of the object */
 } AlterExtensionContentsStmt;
 
 /* ----------------------
@@ -2462,8 +2461,7 @@ typedef struct AlterOpFamilyStmt
 typedef struct DropStmt
 {
 	NodeTag		type;
-	List	   *objects;		/* list of sublists of names (as Values) */
-	List	   *arguments;		/* list of sublists of arguments (as Values) */
+	List	   *objects;		/* list of names */
 	ObjectType	removeType;		/* object type */
 	DropBehavior behavior;		/* RESTRICT or CASCADE behavior */
 	bool		missing_ok;		/* skip error if object is missing? */
@@ -2490,8 +2488,7 @@ typedef struct CommentStmt
 {
 	NodeTag		type;
 	ObjectType	objtype;		/* Object's type */
-	List	   *objname;		/* Qualified name of the object */
-	List	   *objargs;		/* Arguments if needed (eg, for functions) */
+	Node	   *object;			/* Qualified name of the object */
 	char	   *comment;		/* Comment to insert, or NULL to remove */
 } CommentStmt;
 
@@ -2503,8 +2500,7 @@ typedef struct SecLabelStmt
 {
 	NodeTag		type;
 	ObjectType	objtype;		/* Object's type */
-	List	   *objname;		/* Qualified name of the object */
-	List	   *objargs;		/* Arguments if needed (eg, for functions) */
+	Node	   *object;			/* Qualified name of the object */
 	char	   *provider;		/* Label provider (or NULL) */
 	char	   *label;			/* New security label to be assigned */
 } SecLabelStmt;
@@ -2678,8 +2674,7 @@ typedef struct RenameStmt
 	ObjectType	renameType;		/* OBJECT_TABLE, OBJECT_COLUMN, etc */
 	ObjectType	relationType;	/* if column name, associated relation type */
 	RangeVar   *relation;		/* in case it's a table */
-	List	   *object;			/* in case it's some other object */
-	List	   *objarg;			/* argument types, if applicable */
+	Node	   *object;			/* in case it's some other object */
 	char	   *subname;		/* name of contained object (column, rule,
 								 * trigger, etc) */
 	char	   *newname;		/* the new name */
@@ -2696,8 +2691,7 @@ typedef struct AlterObjectDependsStmt
 	NodeTag		type;
 	ObjectType	objectType;		/* OBJECT_FUNCTION, OBJECT_TRIGGER, etc */
 	RangeVar   *relation;		/* in case a table is involved */
-	List	   *objname;		/* name of the object */
-	List	   *objargs;		/* argument types, if applicable */
+	Node	   *object;			/* name of the object */
 	Value	   *extname;		/* extension name */
 } AlterObjectDependsStmt;
 
@@ -2710,8 +2704,7 @@ typedef struct AlterObjectSchemaStmt
 	NodeTag		type;
 	ObjectType	objectType;		/* OBJECT_TABLE, OBJECT_TYPE, etc */
 	RangeVar   *relation;		/* in case it's a table */
-	List	   *object;			/* in case it's some other object */
-	List	   *objarg;			/* argument types, if applicable */
+	Node	   *object;			/* in case it's some other object */
 	char	   *newschema;		/* the new schema */
 	bool		missing_ok;		/* skip error if missing? */
 } AlterObjectSchemaStmt;
@@ -2725,8 +2718,7 @@ typedef struct AlterOwnerStmt
 	NodeTag		type;
 	ObjectType	objectType;		/* OBJECT_TABLE, OBJECT_TYPE, etc */
 	RangeVar   *relation;		/* in case it's a table */
-	List	   *object;			/* in case it's some other object */
-	List	   *objarg;			/* argument types, if applicable */
+	Node	   *object;			/* in case it's some other object */
 	RoleSpec   *newowner;		/* the new owner */
 } AlterOwnerStmt;