Allow ALTER FUNCTION to change a function's strictness, volatility, and

whether or not it is a security definer. Changing a function's strictness
is required by SQL2003, and the other capabilities make sense. Also, allow
an optional RESTRICT noise word to be specified, for SQL conformance.

Some trivial regression tests added and the documentation has been
updated.

1 files changed, 63 insertions, 21 deletions

diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 69e70821970..a88262d4328 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -11,7 +11,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.483 2005/02/02 06:36:01 neilc Exp $
+ *	  $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.484 2005/03/14 00:19:36 neilc Exp $
  *
  * HISTORY
  *	  AUTHOR			DATE			MAJOR EVENT
@@ -142,7 +142,7 @@ static void doNegateFloat(Value *v);
 		DropUserStmt DropdbStmt DropTableSpaceStmt ExplainStmt FetchStmt
 		GrantStmt IndexStmt InsertStmt ListenStmt LoadStmt
 		LockStmt NotifyStmt ExplainableStmt PreparableStmt
-		CreateFunctionStmt ReindexStmt RemoveAggrStmt
+		CreateFunctionStmt AlterFunctionStmt ReindexStmt RemoveAggrStmt
 		RemoveFuncStmt RemoveOperStmt RenameStmt RevokeStmt
 		RuleActionStmt RuleActionStmtOrEmpty RuleStmt
 		SelectStmt TransactionStmt TruncateStmt
@@ -213,7 +213,7 @@ static void doNegateFloat(Value *v);
 %type <list>	stmtblock stmtmulti
 				OptTableElementList TableElementList OptInherit definition
 				opt_distinct opt_definition func_args
-				func_args_list func_as createfunc_opt_list
+				func_args_list func_as createfunc_opt_list alterfunc_opt_list
 				oper_argtypes RuleActionList RuleActionMulti
 				opt_column_list columnList opt_name_list
 				sort_clause opt_sort_clause sortby_list index_params
@@ -231,7 +231,7 @@ static void doNegateFloat(Value *v);
 
 %type <range>	into_clause OptTempTableName
 
-%type <defelt>	createfunc_opt_item
+%type <defelt>	createfunc_opt_item common_func_opt_item
 %type <fun_param> func_arg
 %type <typnam>	func_return func_type aggr_argtype
 
@@ -486,6 +486,7 @@ stmtmulti:	stmtmulti ';' stmt
 stmt :
 			AlterDatabaseSetStmt
 			| AlterDomainStmt
+			| AlterFunctionStmt
 			| AlterGroupStmt
 			| AlterOwnerStmt
 			| AlterSeqStmt
@@ -3371,14 +3372,21 @@ createfunc_opt_list:
 			| createfunc_opt_list createfunc_opt_item { $$ = lappend($1, $2); }
 	;
 
-createfunc_opt_item:
-			AS func_as
+/*
+ * Options common to both CREATE FUNCTION and ALTER FUNCTION
+ */
+common_func_opt_item:
+			CALLED ON NULL_P INPUT_P
 				{
-					$$ = makeDefElem("as", (Node *)$2);
+					$$ = makeDefElem("strict", (Node *)makeInteger(FALSE));
 				}
-			| LANGUAGE ColId_or_Sconst
+			| RETURNS NULL_P ON NULL_P INPUT_P
 				{
-					$$ = makeDefElem("language", (Node *)makeString($2));
+					$$ = makeDefElem("strict", (Node *)makeInteger(TRUE));
+				}
+			| STRICT_P
+				{
+					$$ = makeDefElem("strict", (Node *)makeInteger(TRUE));
 				}
 			| IMMUTABLE
 				{
@@ -3392,18 +3400,7 @@ createfunc_opt_item:
 				{
 					$$ = makeDefElem("volatility", (Node *)makeString("volatile"));
 				}
-			| CALLED ON NULL_P INPUT_P
-				{
-					$$ = makeDefElem("strict", (Node *)makeInteger(FALSE));
-				}
-			| RETURNS NULL_P ON NULL_P INPUT_P
-				{
-					$$ = makeDefElem("strict", (Node *)makeInteger(TRUE));
-				}
-			| STRICT_P
-				{
-					$$ = makeDefElem("strict", (Node *)makeInteger(TRUE));
-				}
+
 			| EXTERNAL SECURITY DEFINER
 				{
 					$$ = makeDefElem("security", (Node *)makeInteger(TRUE));
@@ -3422,6 +3419,21 @@ createfunc_opt_item:
 				}
 		;
 
+createfunc_opt_item:
+			AS func_as
+				{
+					$$ = makeDefElem("as", (Node *)$2);
+				}
+			| LANGUAGE ColId_or_Sconst
+				{
+					$$ = makeDefElem("language", (Node *)makeString($2));
+				}
+			| common_func_opt_item
+				{
+					$$ = $1;
+				}
+		;
+
 func_as:	Sconst						{ $$ = list_make1(makeString($1)); }
 			| Sconst ',' Sconst
 				{
@@ -3434,6 +3446,36 @@ opt_definition:
 			| /*EMPTY*/								{ $$ = NIL; }
 		;
 
+/*****************************************************************************
+ * ALTER FUNCTION
+ *
+ * RENAME and OWNER subcommands are already provided by the generic
+ * ALTER infrastructure, here we just specify alterations that can
+ * only be applied to functions.
+ *
+ *****************************************************************************/
+AlterFunctionStmt:
+			ALTER FUNCTION function_with_argtypes alterfunc_opt_list opt_restrict
+				{
+					AlterFunctionStmt *n = makeNode(AlterFunctionStmt);
+					n->func = (FuncWithArgs *) $3;
+					n->actions = $4;
+					$$ = (Node *) n;
+				}
+		;
+
+alterfunc_opt_list:
+			/* At least one option must be specified */
+			common_func_opt_item					{ $$ = list_make1($1); }
+			| alterfunc_opt_list common_func_opt_item { $$ = lappend($1, $2); }
+		;
+
+/* Ignored, merely for SQL compliance */
+opt_restrict:
+			RESTRICT
+			| /* EMPTY */
+		;
+
 
 /*****************************************************************************
  *