Remove plpgsql's RENAME declaration, which has bizarre and mostly nonfunctional

behavior, and is so little used that no one has been interested in fixing it.
To ensure that possible uses are covered, remove the ALIAS declaration's
arbitrary restriction that only $n identifiers can be aliased.

(We could alternatively make RENAME act just like ALIAS, but per discussion
having two different ways to do the same thing is probably more confusing than
helpful.)

6 files changed, 10 insertions, 72 deletions

diff --git a/src/pl/plpgsql/src/gram.y b/src/pl/plpgsql/src/gram.y
index ec6b285bf2f..e2e3f203ae0 100644
--- a/src/pl/plpgsql/src/gram.y
+++ b/src/pl/plpgsql/src/gram.y
@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/pl/plpgsql/src/gram.y,v 1.129 2009/11/04 22:26:07 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/pl/plpgsql/src/gram.y,v 1.130 2009/11/05 16:58:36 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -128,7 +128,6 @@ static List				*read_raise_options(void);
 
 %type <declhdr> decl_sect
 %type <varname> decl_varname
-%type <str>		decl_renname
 %type <boolean>	decl_const decl_notnull exit_type
 %type <expr>	decl_defval decl_cursor_query
 %type <dtype>	decl_datatype
@@ -218,7 +217,6 @@ static List				*read_raise_options(void);
 %token	K_PERFORM
 %token	K_ROW_COUNT
 %token	K_RAISE
-%token	K_RENAME
 %token	K_RESULT_OID
 %token	K_RETURN
 %token	K_REVERSE
@@ -382,10 +380,6 @@ decl_statement	: decl_varname decl_const decl_datatype decl_notnull decl_defval
 						plpgsql_ns_additem($4->itemtype,
 										   $4->itemno, $1.name);
 					}
-				| K_RENAME decl_renname K_TO decl_renname ';'
-					{
-						plpgsql_ns_rename($2, $4);
-					}
 				| decl_varname opt_scrollable K_CURSOR
 					{ plpgsql_ns_push($1.name); }
 				  decl_cursor_args decl_is_for decl_cursor_query
@@ -521,9 +515,8 @@ decl_aliasitem	: any_identifier
 						char	*name;
 						PLpgSQL_nsitem *nsi;
 
+						/* XXX should allow block-label-qualified names */
 						plpgsql_convert_ident($1, &name, 1);
-						if (name[0] != '$')
-							yyerror("only positional parameters can be aliased");
 
 						plpgsql_ns_setlocal(false);
 
@@ -532,8 +525,8 @@ decl_aliasitem	: any_identifier
 						{
 							plpgsql_error_lineno = plpgsql_scanner_lineno();
 							ereport(ERROR,
-									(errcode(ERRCODE_UNDEFINED_PARAMETER),
-									 errmsg("function has no parameter \"%s\"",
+									(errcode(ERRCODE_UNDEFINED_OBJECT),
+									 errmsg("variable \"%s\" does not exist",
 											name)));
 						}
 
@@ -573,17 +566,6 @@ decl_varname	: T_WORD
 					}
 				;
 
-/* XXX this is broken because it doesn't allow for T_SCALAR,T_ROW,T_RECORD */
-decl_renname	: T_WORD
-					{
-						char	*name;
-
-						plpgsql_convert_ident(yytext, &name, 1);
-						/* the result must be palloc'd, see plpgsql_ns_rename */
-						$$ = name;
-					}
-				;
-
 decl_const		:
 					{ $$ = false; }
 				| K_CONSTANT
diff --git a/src/pl/plpgsql/src/pl_funcs.c b/src/pl/plpgsql/src/pl_funcs.c
index 274d0271141..790e2e86bac 100644
--- a/src/pl/plpgsql/src/pl_funcs.c
+++ b/src/pl/plpgsql/src/pl_funcs.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_funcs.c,v 1.82 2009/11/04 22:26:07 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_funcs.c,v 1.83 2009/11/05 16:58:36 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -236,48 +236,6 @@ plpgsql_ns_lookup_label(const char *name)
 
 
 /* ----------
- * plpgsql_ns_rename			Rename a namespace entry
- * ----------
- */
-void
-plpgsql_ns_rename(char *oldname, char *newname)
-{
-	PLpgSQL_ns *ns;
-	PLpgSQL_nsitem *newitem;
-	int			i;
-
-	/*
-	 * Lookup name in the namestack
-	 */
-	for (ns = ns_current; ns != NULL; ns = ns->upper)
-	{
-		for (i = 1; i < ns->items_used; i++)
-		{
-			if (strcmp(ns->items[i]->name, oldname) == 0)
-			{
-				newitem = palloc(sizeof(PLpgSQL_nsitem) + strlen(newname));
-				newitem->itemtype = ns->items[i]->itemtype;
-				newitem->itemno = ns->items[i]->itemno;
-				strcpy(newitem->name, newname);
-
-				pfree(oldname);
-				pfree(newname);
-
-				pfree(ns->items[i]);
-				ns->items[i] = newitem;
-				return;
-			}
-		}
-	}
-
-	ereport(ERROR,
-			(errcode(ERRCODE_UNDEFINED_OBJECT),
-			 errmsg("variable \"%s\" does not exist in the current block",
-					oldname)));
-}
-
-
-/* ----------
  * plpgsql_convert_ident
  *
  * Convert a possibly-qualified identifier to internal form: handle
diff --git a/src/pl/plpgsql/src/plpgsql.h b/src/pl/plpgsql/src/plpgsql.h
index 3d0f155a884..193d8d5c4c6 100644
--- a/src/pl/plpgsql/src/plpgsql.h
+++ b/src/pl/plpgsql/src/plpgsql.h
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/pl/plpgsql/src/plpgsql.h,v 1.118 2009/11/04 22:26:07 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/pl/plpgsql/src/plpgsql.h,v 1.119 2009/11/05 16:58:36 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -287,7 +287,7 @@ typedef struct
 {								/* Item in the compilers namestack	*/
 	int			itemtype;
 	int			itemno;
-	char		name[1];
+	char		name[1];		/* actually, as long as needed */
 } PLpgSQL_nsitem;
 
 
@@ -851,7 +851,6 @@ extern void plpgsql_ns_additem(int itemtype, int itemno, const char *name);
 extern PLpgSQL_nsitem *plpgsql_ns_lookup(const char *name1, const char *name2,
 				  const char *name3, int *names_used);
 extern PLpgSQL_nsitem *plpgsql_ns_lookup_label(const char *name);
-extern void plpgsql_ns_rename(char *oldname, char *newname);
 
 /* ----------
  * Other functions in pl_funcs.c
diff --git a/src/pl/plpgsql/src/scan.l b/src/pl/plpgsql/src/scan.l
index b309d811872..3563b2ff154 100644
--- a/src/pl/plpgsql/src/scan.l
+++ b/src/pl/plpgsql/src/scan.l
@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/pl/plpgsql/src/scan.l,v 1.72 2009/09/29 20:05:29 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/pl/plpgsql/src/scan.l,v 1.73 2009/11/05 16:58:36 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -183,7 +183,6 @@ open			{ return K_OPEN;			}
 or				{ return K_OR;				}
 perform			{ return K_PERFORM;			}
 raise			{ return K_RAISE;			}
-rename			{ return K_RENAME;			}
 result_oid		{ return K_RESULT_OID;		}
 return			{ return K_RETURN;			}
 reverse			{ return K_REVERSE;			}
diff --git a/src/test/regress/expected/plpgsql.out b/src/test/regress/expected/plpgsql.out
index e3cacf589ec..2e97bec42e9 100644
--- a/src/test/regress/expected/plpgsql.out
+++ b/src/test/regress/expected/plpgsql.out
@@ -162,7 +162,7 @@ create trigger tg_pfield_ad after delete
 create function tg_pslot_biu() returns trigger as $proc$
 declare
     pfrec	record;
-    rename new to ps;
+    ps          alias for new;
 begin
     select into pfrec * from PField where name = ps.pfname;
     if not found then
diff --git a/src/test/regress/sql/plpgsql.sql b/src/test/regress/sql/plpgsql.sql
index 3e6b6de539e..83cda97d1bf 100644
--- a/src/test/regress/sql/plpgsql.sql
+++ b/src/test/regress/sql/plpgsql.sql
@@ -211,7 +211,7 @@ create trigger tg_pfield_ad after delete
 create function tg_pslot_biu() returns trigger as $proc$
 declare
     pfrec	record;
-    rename new to ps;
+    ps          alias for new;
 begin
     select into pfrec * from PField where name = ps.pfname;
     if not found then