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.

3 files changed, 45 insertions, 46 deletions

diff --git a/src/include/nodes/nodes.h b/src/include/nodes/nodes.h
index 7f6a08f450f..fa9d318509b 100644
--- a/src/include/nodes/nodes.h
+++ b/src/include/nodes/nodes.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/nodes/nodes.h,v 1.203 2007/08/21 01:11:27 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/nodes/nodes.h,v 1.204 2007/09/03 18:46:30 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -275,7 +275,6 @@ typedef enum NodeTag
 	T_AlterSeqStmt,
 	T_VariableSetStmt,
 	T_VariableShowStmt,
-	T_VariableResetStmt,
 	T_DiscardStmt,
 	T_CreateTrigStmt,
 	T_DropPropertyStmt,
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 79449c55847..412fadac54e 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/nodes/parsenodes.h,v 1.352 2007/08/22 05:13:50 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/nodes/parsenodes.h,v 1.353 2007/09/03 18:46:30 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1051,6 +1051,42 @@ typedef struct CopyStmt
 } CopyStmt;
 
 /* ----------------------
+ * SET Statement (includes RESET)
+ *
+ * "SET var TO DEFAULT" and "RESET var" are semantically equivalent, but we
+ * preserve the distinction in VariableSetKind for CreateCommandTag().
+ * ----------------------
+ */
+typedef enum
+{
+	VAR_SET_VALUE,				/* SET var = value */
+	VAR_SET_DEFAULT,			/* SET var TO DEFAULT */
+	VAR_SET_CURRENT,			/* SET var FROM CURRENT */
+	VAR_SET_MULTI,				/* special case for SET TRANSACTION ... */
+	VAR_RESET,					/* RESET var */
+	VAR_RESET_ALL				/* RESET ALL */
+} VariableSetKind;
+
+typedef struct VariableSetStmt
+{
+	NodeTag		type;
+	VariableSetKind kind;
+	char	   *name;			/* variable to be set */
+	List	   *args;			/* List of A_Const nodes */
+	bool		is_local;		/* SET LOCAL? */
+} VariableSetStmt;
+
+/* ----------------------
+ * Show Statement
+ * ----------------------
+ */
+typedef struct VariableShowStmt
+{
+	NodeTag		type;
+	char	   *name;
+} VariableShowStmt;
+
+/* ----------------------
  *		Create Table Statement
  *
  * NOTE: in the raw gram.y output, ColumnDef, Constraint, and FkConstraint
@@ -1264,8 +1300,7 @@ typedef struct AlterRoleSetStmt
 {
 	NodeTag		type;
 	char	   *role;			/* role name */
-	char	   *variable;		/* GUC variable name */
-	List	   *value;			/* value for variable, or NIL for Reset */
+	VariableSetStmt *setstmt;	/* SET or RESET subcommand */
 } AlterRoleSetStmt;
 
 typedef struct DropRoleStmt
@@ -1781,9 +1816,8 @@ typedef struct AlterDatabaseStmt
 typedef struct AlterDatabaseSetStmt
 {
 	NodeTag		type;
-	char	   *dbname;
-	char	   *variable;
-	List	   *value;
+	char	   *dbname;			/* database name */
+	VariableSetStmt *setstmt;	/* SET or RESET subcommand */
 } AlterDatabaseSetStmt;
 
 /* ----------------------
@@ -1849,41 +1883,6 @@ typedef struct CheckPointStmt
 } CheckPointStmt;
 
 /* ----------------------
- * Set Statement
- * ----------------------
- */
-
-typedef struct VariableSetStmt
-{
-	NodeTag		type;
-	char	   *name;
-	List	   *args;
-	bool		is_local;		/* SET LOCAL */
-} VariableSetStmt;
-
-/* ----------------------
- * Show Statement
- * ----------------------
- */
-
-typedef struct VariableShowStmt
-{
-	NodeTag		type;
-	char	   *name;
-} VariableShowStmt;
-
-/* ----------------------
- * Reset Statement
- * ----------------------
- */
-
-typedef struct VariableResetStmt
-{
-	NodeTag		type;
-	char	   *name;
-} VariableResetStmt;
-
-/* ----------------------
  * Discard Statement
  * ----------------------
  */
diff --git a/src/include/utils/guc.h b/src/include/utils/guc.h
index 5dd06ee7a12..d8fafff5590 100644
--- a/src/include/utils/guc.h
+++ b/src/include/utils/guc.h
@@ -7,12 +7,13 @@
  * Copyright (c) 2000-2007, PostgreSQL Global Development Group
  * Written by Peter Eisentraut <peter_e@gmx.net>.
  *
- * $PostgreSQL: pgsql/src/include/utils/guc.h,v 1.84 2007/09/03 00:39:25 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/utils/guc.h,v 1.85 2007/09/03 18:46:30 tgl Exp $
  *--------------------------------------------------------------------
  */
 #ifndef GUC_H
 #define GUC_H
 
+#include "nodes/parsenodes.h"
 #include "tcop/dest.h"
 #include "utils/array.h"
 
@@ -203,9 +204,9 @@ extern int	GetNumConfigOptions(void);
 extern void SetPGVariable(const char *name, List *args, bool is_local);
 extern void GetPGVariable(const char *name, DestReceiver *dest);
 extern TupleDesc GetPGVariableResultDesc(const char *name);
-extern void ResetPGVariable(const char *name, bool isTopLevel);
 
-extern char *flatten_set_variable_args(const char *name, List *args);
+extern void ExecSetVariableStmt(VariableSetStmt *stmt);
+extern char *ExtractSetVariableArgs(VariableSetStmt *stmt);
 
 extern void ProcessGUCArray(ArrayType *array,
 						GucContext context, GucSource source, bool isLocal);