Promote row expressions to full-fledged citizens of the expression syntax,

rather than allowing them only in a few special cases as before.  In
particular you can now pass a ROW() construct to a function that accepts
a rowtype parameter.  Internal generation of RowExprs fixes a number of
corner cases that used to not work very well, such as referencing the
whole-row result of a JOIN or subquery.  This represents a further step in
the work I started a month or so back to make rowtype values into
first-class citizens.

4 files changed, 36 insertions, 4 deletions

diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 8a0fbf7be0f..325bf876800 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/nodes/execnodes.h,v 1.115 2004/04/01 21:28:46 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/nodes/execnodes.h,v 1.116 2004/05/10 22:44:49 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -614,6 +614,17 @@ typedef struct ArrayExprState
 } ArrayExprState;
 
 /* ----------------
+ *		RowExprState node
+ * ----------------
+ */
+typedef struct RowExprState
+{
+	ExprState	xprstate;
+	List	   *args;			/* the arguments */
+	TupleDesc	tupdesc;		/* descriptor for result tuples */
+} RowExprState;
+
+/* ----------------
  *		CoalesceExprState node
  * ----------------
  */
diff --git a/src/include/nodes/makefuncs.h b/src/include/nodes/makefuncs.h
index 7562e1a82b6..085e76d03bf 100644
--- a/src/include/nodes/makefuncs.h
+++ b/src/include/nodes/makefuncs.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/nodes/makefuncs.h,v 1.48 2003/11/29 22:41:06 pgsql Exp $
+ * $PostgreSQL: pgsql/src/include/nodes/makefuncs.h,v 1.49 2004/05/10 22:44:49 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -45,6 +45,8 @@ extern Const *makeConst(Oid consttype,
 
 extern Const *makeNullConst(Oid consttype);
 
+extern Node *makeBoolConst(bool value, bool isnull);
+
 extern Expr *makeBoolExpr(BoolExprType boolop, List *args);
 
 extern Alias *makeAlias(const char *aliasname, List *colnames);
diff --git a/src/include/nodes/nodes.h b/src/include/nodes/nodes.h
index a776607ec66..20c1b08f5c5 100644
--- a/src/include/nodes/nodes.h
+++ b/src/include/nodes/nodes.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/nodes/nodes.h,v 1.153 2004/05/05 04:48:47 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/nodes/nodes.h,v 1.154 2004/05/10 22:44:49 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -115,6 +115,7 @@ typedef enum NodeTag
 	T_CaseWhen,
 	T_CaseTestExpr,
 	T_ArrayExpr,
+	T_RowExpr,
 	T_CoalesceExpr,
 	T_NullIfExpr,
 	T_NullTest,
@@ -145,6 +146,7 @@ typedef enum NodeTag
 	T_CaseExprState,
 	T_CaseWhenState,
 	T_ArrayExprState,
+	T_RowExprState,
 	T_CoalesceExprState,
 	T_CoerceToDomainState,
 	T_DomainConstraintState,
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index 567310fa1c3..d5819eab7bb 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -10,7 +10,7 @@
  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/nodes/primnodes.h,v 1.97 2004/04/01 21:28:46 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/nodes/primnodes.h,v 1.98 2004/05/10 22:44:49 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -633,6 +633,23 @@ typedef struct ArrayExpr
 } ArrayExpr;
 
 /*
+ * RowExpr - a ROW() expression
+ */
+typedef struct RowExpr
+{
+	Expr		xpr;
+	List	   *args;			/* the fields */
+	Oid			row_typeid;		/* RECORDOID or a composite type's ID */
+	/*
+	 * Note: we deliberately do NOT store a typmod.  Although a typmod
+	 * will be associated with specific RECORD types at runtime, it will
+	 * differ for different backends, and so cannot safely be stored in
+	 * stored parsetrees.  We must assume typmod -1 for a RowExpr node.
+	 */
+	CoercionForm row_format;	/* how to display this node */
+} RowExpr;
+
+/*
  * CoalesceExpr - a COALESCE expression
  */
 typedef struct CoalesceExpr