Support SET FROM CURRENT in CREATE/ALTER FUNCTION, ALTER DATABASE, ALTER ROLE.

(Actually, it works as a plain statement too, but I didn't document that
because it seems a bit useless.)  Unify VariableResetStmt with
VariableSetStmt, and clean up some ancient cruft in the representation of
same.

1 files changed, 87 insertions, 83 deletions

diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 9f9f644168f..a7521eca522 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 2.601 2007/09/03 00:39:16 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.602 2007/09/03 18:46:30 tgl Exp $
  *
  * HISTORY
  *	  AUTHOR			DATE			MAJOR EVENT
@@ -292,7 +292,7 @@ static Node *makeXmlExpr(XmlExprOp op, char *name, List *named_args, List *args)
 
 %type <istmt>	insert_rest
 
-%type <vsetstmt> set_rest
+%type <vsetstmt> set_rest SetResetClause
 
 %type <node>	TableElement ConstraintElem TableFuncElement
 %type <node>	columnDef
@@ -330,7 +330,7 @@ static Node *makeXmlExpr(XmlExprOp op, char *name, List *named_args, List *args)
 %type <ival>	Iconst SignedIconst
 %type <str>		Sconst comment_text
 %type <str>		RoleId opt_granted_by opt_boolean ColId_or_Sconst
-%type <list>	var_list var_list_or_default
+%type <list>	var_list
 %type <str>		ColId ColLabel var_name type_function_name param_name
 %type <node>	var_value zone_value
 
@@ -796,20 +796,11 @@ AlterRoleStmt:
 		;
 
 AlterRoleSetStmt:
-			ALTER ROLE RoleId SET set_rest
+			ALTER ROLE RoleId SetResetClause
 				{
 					AlterRoleSetStmt *n = makeNode(AlterRoleSetStmt);
 					n->role = $3;
-					n->variable = $5->name;
-					n->value = $5->args;
-					$$ = (Node *)n;
-				}
-			| ALTER ROLE RoleId VariableResetStmt
-				{
-					AlterRoleSetStmt *n = makeNode(AlterRoleSetStmt);
-					n->role = $3;
-					n->variable = ((VariableResetStmt *)$4)->name;
-					n->value = NIL;
+					n->setstmt = $4;
 					$$ = (Node *)n;
 				}
 		;
@@ -834,20 +825,11 @@ AlterUserStmt:
 
 
 AlterUserSetStmt:
-			ALTER USER RoleId SET set_rest
+			ALTER USER RoleId SetResetClause
 				{
 					AlterRoleSetStmt *n = makeNode(AlterRoleSetStmt);
 					n->role = $3;
-					n->variable = $5->name;
-					n->value = $5->args;
-					$$ = (Node *)n;
-				}
-			| ALTER USER RoleId VariableResetStmt
-				{
-					AlterRoleSetStmt *n = makeNode(AlterRoleSetStmt);
-					n->role = $3;
-					n->variable = ((VariableResetStmt *)$4)->name;
-					n->value = NIL;
+					n->setstmt = $4;
 					$$ = (Node *)n;
 				}
 			;
@@ -1056,31 +1038,60 @@ VariableSetStmt:
 				}
 		;
 
-set_rest:  var_name TO var_list_or_default
+set_rest:	/* Generic SET syntaxes: */
+			var_name TO var_list
 				{
 					VariableSetStmt *n = makeNode(VariableSetStmt);
+					n->kind = VAR_SET_VALUE;
 					n->name = $1;
 					n->args = $3;
 					$$ = n;
 				}
-			| var_name '=' var_list_or_default
+			| var_name '=' var_list
 				{
 					VariableSetStmt *n = makeNode(VariableSetStmt);
+					n->kind = VAR_SET_VALUE;
 					n->name = $1;
 					n->args = $3;
 					$$ = n;
 				}
+			| var_name TO DEFAULT
+				{
+					VariableSetStmt *n = makeNode(VariableSetStmt);
+					n->kind = VAR_SET_DEFAULT;
+					n->name = $1;
+					$$ = n;
+				}
+			| var_name '=' DEFAULT
+				{
+					VariableSetStmt *n = makeNode(VariableSetStmt);
+					n->kind = VAR_SET_DEFAULT;
+					n->name = $1;
+					$$ = n;
+				}
+			| var_name FROM CURRENT_P
+				{
+					VariableSetStmt *n = makeNode(VariableSetStmt);
+					n->kind = VAR_SET_CURRENT;
+					n->name = $1;
+					$$ = n;
+				}
+			/* Special syntaxes mandated by SQL standard: */
 			| TIME ZONE zone_value
 				{
 					VariableSetStmt *n = makeNode(VariableSetStmt);
+					n->kind = VAR_SET_VALUE;
 					n->name = "timezone";
 					if ($3 != NULL)
 						n->args = list_make1($3);
+					else
+						n->kind = VAR_SET_DEFAULT;
 					$$ = n;
 				}
 			| TRANSACTION transaction_mode_list
 				{
 					VariableSetStmt *n = makeNode(VariableSetStmt);
+					n->kind = VAR_SET_MULTI;
 					n->name = "TRANSACTION";
 					n->args = $2;
 					$$ = n;
@@ -1088,6 +1099,7 @@ set_rest:  var_name TO var_list_or_default
 			| SESSION CHARACTERISTICS AS TRANSACTION transaction_mode_list
 				{
 					VariableSetStmt *n = makeNode(VariableSetStmt);
+					n->kind = VAR_SET_MULTI;
 					n->name = "SESSION CHARACTERISTICS";
 					n->args = $5;
 					$$ = n;
@@ -1095,14 +1107,18 @@ set_rest:  var_name TO var_list_or_default
 			| NAMES opt_encoding
 				{
 					VariableSetStmt *n = makeNode(VariableSetStmt);
+					n->kind = VAR_SET_VALUE;
 					n->name = "client_encoding";
 					if ($2 != NULL)
 						n->args = list_make1(makeStringConst($2, NULL));
+					else
+						n->kind = VAR_SET_DEFAULT;
 					$$ = n;
 				}
 			| ROLE ColId_or_Sconst
 				{
 					VariableSetStmt *n = makeNode(VariableSetStmt);
+					n->kind = VAR_SET_VALUE;
 					n->name = "role";
 					n->args = list_make1(makeStringConst($2, NULL));
 					$$ = n;
@@ -1110,6 +1126,7 @@ set_rest:  var_name TO var_list_or_default
 			| SESSION AUTHORIZATION ColId_or_Sconst
 				{
 					VariableSetStmt *n = makeNode(VariableSetStmt);
+					n->kind = VAR_SET_VALUE;
 					n->name = "session_authorization";
 					n->args = list_make1(makeStringConst($3, NULL));
 					$$ = n;
@@ -1117,37 +1134,28 @@ set_rest:  var_name TO var_list_or_default
 			| SESSION AUTHORIZATION DEFAULT
 				{
 					VariableSetStmt *n = makeNode(VariableSetStmt);
+					n->kind = VAR_SET_DEFAULT;
 					n->name = "session_authorization";
-					n->args = NIL;
 					$$ = n;
 				}
 			| XML_P OPTION document_or_content
 				{
 					VariableSetStmt *n = makeNode(VariableSetStmt);
+					n->kind = VAR_SET_VALUE;
 					n->name = "xmloption";
 					n->args = list_make1(makeStringConst($3 == XMLOPTION_DOCUMENT ? "DOCUMENT" : "CONTENT", NULL));
 					$$ = n;
 				}
 		;
 
-var_name:
-			ColId								{ $$ = $1; }
+var_name:	ColId								{ $$ = $1; }
 			| var_name '.' ColId
 				{
-					int qLen = strlen($1);
-					char* qualName = palloc(qLen + strlen($3) + 2);
-					strcpy(qualName, $1);
-					qualName[qLen] = '.';
-					strcpy(qualName + qLen + 1, $3);
-					$$ = qualName;
+					$$ = palloc(strlen($1) + strlen($3) + 2);
+					sprintf($$, "%s.%s", $1, $3);
 				}
 		;
 
-var_list_or_default:
-			var_list								{ $$ = $1; }
-			| DEFAULT								{ $$ = NIL; }
-		;
-
 var_list:	var_value								{ $$ = list_make1($1); }
 			| var_list ',' var_value				{ $$ = lappend($1, $3); }
 		;
@@ -1231,68 +1239,78 @@ ColId_or_Sconst:
 			| SCONST								{ $$ = $1; }
 		;
 
-
-VariableShowStmt:
-			SHOW var_name
+VariableResetStmt:
+			RESET var_name
 				{
-					VariableShowStmt *n = makeNode(VariableShowStmt);
+					VariableSetStmt *n = makeNode(VariableSetStmt);
+					n->kind = VAR_RESET;
 					n->name = $2;
 					$$ = (Node *) n;
 				}
-			| SHOW TIME ZONE
+			| RESET TIME ZONE
 				{
-					VariableShowStmt *n = makeNode(VariableShowStmt);
+					VariableSetStmt *n = makeNode(VariableSetStmt);
+					n->kind = VAR_RESET;
 					n->name = "timezone";
 					$$ = (Node *) n;
 				}
-			| SHOW TRANSACTION ISOLATION LEVEL
+			| RESET TRANSACTION ISOLATION LEVEL
 				{
-					VariableShowStmt *n = makeNode(VariableShowStmt);
+					VariableSetStmt *n = makeNode(VariableSetStmt);
+					n->kind = VAR_RESET;
 					n->name = "transaction_isolation";
 					$$ = (Node *) n;
 				}
-			| SHOW SESSION AUTHORIZATION
+			| RESET SESSION AUTHORIZATION
 				{
-					VariableShowStmt *n = makeNode(VariableShowStmt);
+					VariableSetStmt *n = makeNode(VariableSetStmt);
+					n->kind = VAR_RESET;
 					n->name = "session_authorization";
 					$$ = (Node *) n;
 				}
-			| SHOW ALL
+			| RESET ALL
 				{
-					VariableShowStmt *n = makeNode(VariableShowStmt);
-					n->name = "all";
+					VariableSetStmt *n = makeNode(VariableSetStmt);
+					n->kind = VAR_RESET_ALL;
 					$$ = (Node *) n;
 				}
 		;
 
-VariableResetStmt:
-			RESET var_name
+/* SetResetClause allows SET or RESET without LOCAL */
+SetResetClause:
+			SET set_rest					{ $$ = $2; }
+			| VariableResetStmt				{ $$ = (VariableSetStmt *) $1; }
+		;
+
+
+VariableShowStmt:
+			SHOW var_name
 				{
-					VariableResetStmt *n = makeNode(VariableResetStmt);
+					VariableShowStmt *n = makeNode(VariableShowStmt);
 					n->name = $2;
 					$$ = (Node *) n;
 				}
-			| RESET TIME ZONE
+			| SHOW TIME ZONE
 				{
-					VariableResetStmt *n = makeNode(VariableResetStmt);
+					VariableShowStmt *n = makeNode(VariableShowStmt);
 					n->name = "timezone";
 					$$ = (Node *) n;
 				}
-			| RESET TRANSACTION ISOLATION LEVEL
+			| SHOW TRANSACTION ISOLATION LEVEL
 				{
-					VariableResetStmt *n = makeNode(VariableResetStmt);
+					VariableShowStmt *n = makeNode(VariableShowStmt);
 					n->name = "transaction_isolation";
 					$$ = (Node *) n;
 				}
-			| RESET SESSION AUTHORIZATION
+			| SHOW SESSION AUTHORIZATION
 				{
-					VariableResetStmt *n = makeNode(VariableResetStmt);
+					VariableShowStmt *n = makeNode(VariableShowStmt);
 					n->name = "session_authorization";
 					$$ = (Node *) n;
 				}
-			| RESET ALL
+			| SHOW ALL
 				{
-					VariableResetStmt *n = makeNode(VariableResetStmt);
+					VariableShowStmt *n = makeNode(VariableShowStmt);
 					n->name = "all";
 					$$ = (Node *) n;
 				}
@@ -4270,15 +4288,10 @@ common_func_opt_item:
 				{
 					$$ = makeDefElem("rows", (Node *)$2);
 				}
-			| SET set_rest
-				{
-					/* we abuse the normal content of a DefElem here */
-					$$ = makeDefElem("set", (Node *)$2);
-				}
-			| VariableResetStmt
+			| SetResetClause
 				{
 					/* we abuse the normal content of a DefElem here */
-					$$ = makeDefElem("set", $1);
+					$$ = makeDefElem("set", (Node *)$1);
 				}
 		;
 
@@ -5391,20 +5404,11 @@ AlterDatabaseStmt:
 		;
 
 AlterDatabaseSetStmt:
-			ALTER DATABASE database_name SET set_rest
-				{
-					AlterDatabaseSetStmt *n = makeNode(AlterDatabaseSetStmt);
-					n->dbname = $3;
-					n->variable = $5->name;
-					n->value = $5->args;
-					$$ = (Node *)n;
-				}
-			| ALTER DATABASE database_name VariableResetStmt
+			ALTER DATABASE database_name SetResetClause
 				{
 					AlterDatabaseSetStmt *n = makeNode(AlterDatabaseSetStmt);
 					n->dbname = $3;
-					n->variable = ((VariableResetStmt *)$4)->name;
-					n->value = NIL;
+					n->setstmt = $4;
 					$$ = (Node *)n;
 				}
 		;