Add capabilities for automatic type conversion.

src/backend/parser/analyze.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/parser/analyze.c,v 1.74 1998/03/31 23:31:10 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/parser/analyze.c,v 1.75 1998/05/09 23:29:52 thomas Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -30,6 +30,9 @@
 #include "parser/parse_target.h"
 #include "utils/builtins.h"
 #include "utils/mcxt.h"
+#ifdef PARSEDEBUG
+#include "nodes/print.h"
+#endif
 
 static Query *transformStmt(ParseState *pstate, Node *stmt);
 static Query *transformDeleteStmt(ParseState *pstate, DeleteStmt *stmt);
@@ -65,6 +68,10 @@ parse_analyze(List *pl, ParseState *parentParseState)
 
 	while (pl != NIL)
 	{
+#ifdef PARSEDEBUG
+		elog(DEBUG,"parse tree from yacc:\n---\n%s\n---\n", nodeToString(lfirst(pl)));
+#endif
+
 		pstate = make_parsestate(parentParseState);
 		result->qtrees[i++] = transformStmt(pstate, lfirst(pl));
 		if (pstate->p_target_relation != NULL)

src/backend/parser/parse_expr.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/parser/parse_expr.c,v 1.27 1998/04/26 04:06:45 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/parser/parse_expr.c,v 1.28 1998/05/09 23:29:53 thomas Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -301,12 +301,14 @@ transformExpr(ParseState *pstate, Node *expr, int precedence)
 				result = (Node *) expr;
 				break;
 			}
-/* These nodes do _not_ come from the original parse tree.
- * They result from parser transformation in this phase.
+
+/* These nodes do _not_ come from the original parse tree,
+ *  but result from parser transformation in this phase.
  * At least one construct (BETWEEN/AND) puts the same nodes
- *  into two branches of the parse tree. Hence, some nodes
- *  are transformed twice. These nodes come from transforming
- *  a function call. Let's try just passing them through...
+ *  into two branches of the parse tree; hence, some nodes
+ *  are transformed twice.
+ * These cases below come from transforming function calls.
+ * Let's try just passing them through...
  * - thomas 1998-03-14
  */
 		case T_Expr:
@@ -506,6 +508,10 @@ parser_typecast(Value *expr, TypeName *typename, int16 atttypmod)
 	return (Node *) adt;
 }
 
+
+/* parser_typecast2()
+ * Convert (only) constants to specified type.
+ */
 Node *
 parser_typecast2(Node *expr, Oid exprType, Type tp, int16 atttypmod)
 {

src/backend/parser/parse_node.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/parser/parse_node.c,v 1.14 1998/02/26 04:33:32 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/parser/parse_node.c,v 1.15 1998/05/09 23:29:53 thomas Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -39,7 +39,7 @@ make_operand(char *opname,
 /*
  * make_parsestate() --
  *	  allocate and initialize a new ParseState.
- *	the CALLERS is responsible for freeing the ParseState* returned
+ *	the CALLER is responsible for freeing the ParseState* returned
  *
  */
 
@@ -57,6 +57,15 @@ make_parsestate(ParseState *parentParseState)
 	return (pstate);
 }
 
+
+extern
+Node *
+coerce_type(ParseState *pstate, Node *node, Oid inputTypeId, Oid targetTypeId);
+
+
+/* make_operand()
+ * Ensure argument type match by forcing conversion of constants.
+ */
 static Node *
 make_operand(char *opname,
 			 Node *tree,
@@ -65,35 +74,33 @@ make_operand(char *opname,
 {
 	Node	   *result;
 	Type		true_type;
+#if FALSE
 	Datum		val;
 	Oid			infunc;
+#endif
 
+#ifdef PARSEDEBUG
+printf("make_operand: constructing operand for '%s' %s->%s\n",
+ opname, typeidTypeName(orig_typeId), typeidTypeName(true_typeId));
+#endif
 	if (tree != NULL)
 	{
 		result = tree;
 		true_type = typeidType(true_typeId);
 		disallow_setop(opname, true_type, result);
+
+		/* must coerce? */
 		if (true_typeId != orig_typeId)
-		{						/* must coerce */
-			Const	   *con = (Const *) result;
-
-			Assert(nodeTag(result) == T_Const);
-			val = (Datum) textout((struct varlena *)
-								  con->constvalue);
-			infunc = typeidInfunc(true_typeId);
-			con = makeNode(Const);
-			con->consttype = true_typeId;
-			con->constlen = typeLen(true_type);
-			con->constvalue = (Datum) fmgr(infunc,
-										   val,
-										   typeidTypElem(true_typeId),
-										   -1 /* for varchar() type */ );
-			con->constisnull = false;
-			con->constbyval = true;
-			con->constisset = false;
-			result = (Node *) con;
+		{
+#ifdef PARSEDEBUG
+printf("make_operand: try to convert node from %s to %s\n",
+ typeidTypeName(orig_typeId), typeidTypeName(true_typeId));
+#endif
+			result = coerce_type(NULL, tree, orig_typeId, true_typeId);
 		}
 	}
+
+	/* otherwise, this is a NULL value */
 	else
 	{
 		Const	   *con = makeNode(Const);
@@ -108,7 +115,7 @@ make_operand(char *opname,
 	}
 
 	return result;
-}
+} /* make_operand() */
 
 
 static void
@@ -119,13 +126,49 @@ disallow_setop(char *op, Type optype, Node *operand)
 
 	if (nodeTag(operand) == T_Iter)
 	{
-		elog(NOTICE, "An operand to the '%s' operator returns a set of %s,",
-			 op, typeTypeName(optype));
-		elog(ERROR, "but '%s' takes single values, not sets.",
-			 op);
+		elog(ERROR, "An operand to the '%s' operator returns a set of %s,"
+			 "\n\tbut '%s' takes single values, not sets.",
+			 op, typeTypeName(optype), op);
 	}
 }
 
+
+/* CoerceType()
+ * Try to force type of node.
+ */
+Oid CoerceType(Oid typeId, Node *node);
+
+Oid
+CoerceType(Oid typeId, Node *node)
+{
+	switch (nodeTag(node))
+	{
+		case T_Const:
+			{
+				Const	   *con = (Const *) node;
+			
+#ifdef PARSEDEBUG
+printf( "Convert node %d to text\n", nodeTag(node));
+#endif
+
+				typeId = TEXTOID;
+				con->consttype = typeId;
+			}
+			break;
+
+		default:
+			break;
+	}
+	return typeId;
+} /* CoerceType() */
+
+
+/* make_op()
+ * Operator construction.
+ *
+ * Transform operator expression ensuring type compatibility.
+ * This is where some type conversion happens.
+ */
 Expr *
 make_op(char *opname, Node *ltree, Node *rtree)
 {
@@ -138,10 +181,9 @@ make_op(char *opname, Node *ltree, Node *rtree)
 			   *right;
 	Expr	   *result;
 
+	/* right operator? */
 	if (rtree == NULL)
 	{
-
-		/* right operator */
 		ltypeId = (ltree == NULL) ? UNKNOWNOID : exprType(ltree);
 		temp = right_oper(opname, ltypeId);
 		opform = (OperatorTupleForm) GETSTRUCT(temp);
@@ -149,25 +191,29 @@ make_op(char *opname, Node *ltree, Node *rtree)
 		right = NULL;
 
 	}
+
+	/* left operator? */
 	else if (ltree == NULL)
 	{
-
-		/* left operator */
 		rtypeId = (rtree == NULL) ? UNKNOWNOID : exprType(rtree);
 		temp = left_oper(opname, rtypeId);
+#ifdef PARSEDEBUG
+printf("make_op: returned from left_oper() with structure at %p\n", (void *)temp);
+#endif
 		opform = (OperatorTupleForm) GETSTRUCT(temp);
+#ifdef PARSEDEBUG
+printf("make_op: calling make_operand()\n");
+#endif
 		right = make_operand(opname, rtree, rtypeId, opform->oprright);
 		left = NULL;
 
 	}
+
+	/* otherwise, binary operator */
 	else
 	{
-		char	   *outstr;
-		Oid			infunc,
-					outfunc;
-		Type		newtype;
 
-#define CONVERTABLE_TYPE(t) (	(t) == INT2OID || \
+#define CONVERTIBLE_TYPE(t) (	(t) == INT2OID || \
 								(t) == INT4OID || \
 								(t) == OIDOID || \
 								(t) == FLOAT4OID || \
@@ -178,12 +224,32 @@ make_op(char *opname, Node *ltree, Node *rtree)
 		ltypeId = (ltree == NULL) ? UNKNOWNOID : exprType(ltree);
 		rtypeId = (rtree == NULL) ? UNKNOWNOID : exprType(rtree);
 
+#if FALSE
+		/* Both operands of unknown type?
+		 * Then they are strings and we should force at least one to text
+		 * - thomas 1998-03-16
+		 */
+		ltypeId = exprType(ltree);
+		rtypeId = exprType(rtree);
+
+		if ((ltypeId == UNKNOWNOID)
+		 && (rtypeId == UNKNOWNOID))
+		{
+#ifdef PARSEDEBUG
+printf( "Convert left-hand constant to text for node %d\n", nodeTag(ltree));
+#endif
+
+			ltypeId = CoerceType(TEXTOID, ltree);
+		}
+#endif
+
+#if FALSE
 		/*
 		 * convert constant when using a const of a numeric type and a
 		 * non-const of another numeric type
 		 */
-		if (CONVERTABLE_TYPE(ltypeId) && nodeTag(ltree) != T_Const &&
-			CONVERTABLE_TYPE(rtypeId) && nodeTag(rtree) == T_Const &&
+		if (CONVERTIBLE_TYPE(ltypeId) && nodeTag(ltree) != T_Const &&
+			CONVERTIBLE_TYPE(rtypeId) && nodeTag(rtree) == T_Const &&
 			!((Const *) rtree)->constiscast)
 		{
 			outfunc = typeidOutfunc(rtypeId);
@@ -197,8 +263,8 @@ make_op(char *opname, Node *ltree, Node *rtree)
 			((Const *) rtree)->constbyval = typeByVal(newtype);
 		}
 
-		if (CONVERTABLE_TYPE(rtypeId) && nodeTag(rtree) != T_Const &&
-			CONVERTABLE_TYPE(ltypeId) && nodeTag(ltree) == T_Const &&
+		if (CONVERTIBLE_TYPE(rtypeId) && nodeTag(rtree) != T_Const &&
+			CONVERTIBLE_TYPE(ltypeId) && nodeTag(ltree) == T_Const &&
 			!((Const *) ltree)->constiscast)
 		{
 			outfunc = typeidOutfunc(ltypeId);
@@ -211,6 +277,7 @@ make_op(char *opname, Node *ltree, Node *rtree)
 			((Const *) ltree)->constlen = typeLen(newtype);
 			((Const *) ltree)->constbyval = typeByVal(newtype);
 		}
+#endif
 
 		temp = oper(opname, ltypeId, rtypeId, false);
 		opform = (OperatorTupleForm) GETSTRUCT(temp);
@@ -219,8 +286,8 @@ make_op(char *opname, Node *ltree, Node *rtree)
 	}
 
 	newop = makeOper(oprid(temp),		/* opno */
-					 InvalidOid,/* opid */
-					 opform->oprresult, /* operator result type */
+					 InvalidOid,		/* opid */
+					 opform->oprresult,	/* operator result type */
 					 0,
 					 NULL);
 
@@ -239,6 +306,7 @@ make_op(char *opname, Node *ltree, Node *rtree)
 	return result;
 }
 
+
 Var *
 make_var(ParseState *pstate, Oid relid, char *refname,
 		 char *attrname)
@@ -356,6 +424,9 @@ make_array_ref(Node *expr,
 	return aref;
 }
 
+
+/* make_array_set()
+ */
 ArrayRef   *
 make_array_set(Expr *target_expr,
 			   List *upperIndexpr,
@@ -406,10 +477,12 @@ make_array_set(Expr *target_expr,
 	aref->refexpr = (Node *) target_expr;
 	aref->refassgnexpr = (Node *) expr;
 
-	if (lowerIndexpr == NIL)	/* accessing a single array element */
+	/* accessing a single array element? */
+	if (lowerIndexpr == NIL)
 		reftype = aref->refelemtype;
+
+	/* otherwise, request to set a part of the array, by another array */
 	else
-/* request to set a part of the array, by another array */
 		reftype = typearray;
 
 	aref->refelemtype = reftype;

src/backend/parser/parse_type.c

 /*-------------------------------------------------------------------------
  *
- * parse_type.h
+ * parse_type.c
  *		handle type operations for parser
  *
  * Copyright (c) 1994, Regents of the University of California
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/parser/parse_type.c,v 1.8 1998/02/27 19:44:51 scrappy Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/parser/parse_type.c,v 1.9 1998/05/09 23:29:54 thomas Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -15,11 +15,17 @@
 #include "postgres.h"
 #include "fmgr.h"
 
+#include "nodes/nodes.h"
+#include "nodes/parsenodes.h"
+#include "nodes/primnodes.h"
+#include "parser/parse_node.h"
+
 #include "catalog/pg_type.h"
 #include "parser/parse_target.h"
 #include "parser/parse_type.h"
 #include "utils/syscache.h"
 
+
 /* check to see if a type id is valid,
  * returns true if it is. By using this call before calling
  * typeidType or typeidTypeName, more meaningful error messages

src/include/parser/parse_coerce.h

+/*-------------------------------------------------------------------------
+ *
+ * parse_coerce.h
+ *
+ *
+ *
+ * Copyright (c) 1994, Regents of the University of California
+ *
+ * $Id: parse_coerce.h,v 1.1 1998/05/09 23:31:34 thomas Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef PARSE_COERCE_H
+#define PARSE_COERCE_H
+
+typedef enum CATEGORY {
+	INVALID_TYPE,
+	UNKNOWN_TYPE,
+	BOOLEAN_TYPE,
+	STRING_TYPE,
+	NUMERIC_TYPE,
+	DATETIME_TYPE,
+	TIMESPAN_TYPE,
+	GEOMETRIC_TYPE,
+	USER_TYPE,
+	MIXED_TYPE
+} CATEGORY;
+
+
+#define IS_BUILTIN_TYPE(t) \
+		  (((t) == BOOLOID) \
+		|| ((t) == BPCHAROID) \
+		|| ((t) == VARCHAROID) \
+		|| ((t) == TEXTOID) \
+		|| ((t) == CASHOID) \
+		|| ((t) == INT4OID) \
+		|| ((t) == DATETIMEOID) \
+		|| ((t) == FLOAT8OID) \
+		|| ((t) == ABSTIMEOID) \
+		|| ((t) == TIMESTAMPOID) \
+		|| ((t) == RELTIMEOID))
+
+
+/* IS_BINARY_COMPATIBLE()
+ * Check for types with the same underlying binary representation.
+ * This allows us to cheat and directly exchange values without
+ *  going through the trouble of calling a conversion function.
+ */
+#define IS_BINARY_COMPATIBLE(a,b) \
+		  (((a) == BPCHAROID && (b) == TEXTOID) \
+		|| ((a) == BPCHAROID && (b) == VARCHAROID) \
+		|| ((a) == VARCHAROID && (b) == TEXTOID) \
+		|| ((a) == VARCHAROID && (b) == BPCHAROID) \
+		|| ((a) == TEXTOID && (b) == BPCHAROID) \
+		|| ((a) == TEXTOID && (b) == VARCHAROID) \
+		|| ((a) == CASHOID && (b) == INT4OID) \
+		|| ((a) == INT4OID && (b) == CASHOID) \
+		|| ((a) == DATETIMEOID && (b) == FLOAT8OID) \
+		|| ((a) == FLOAT8OID && (b) == DATETIMEOID) \
+		|| ((a) == ABSTIMEOID && (b) == TIMESTAMPOID) \
+		|| ((a) == TIMESTAMPOID && (b) == ABSTIMEOID) \
+		|| ((a) == ABSTIMEOID && (b) == INT4OID) \
+		|| ((a) == INT4OID && (b) == ABSTIMEOID) \
+		|| ((a) == RELTIMEOID && (b) == INT4OID) \
+		|| ((a) == INT4OID && (b) == RELTIMEOID))
+
+/* IS_HIGHER_TYPE()
+ * These types are the most general in each of the type categories.
+ */
+#define IS_HIGHER_TYPE(t) \
+		  (((t) == TEXTOID) \
+		|| ((t) == FLOAT8OID) \
+		|| ((t) == TIMESPANOID) \
+		|| ((t) == DATETIMEOID) \
+		|| ((t) == POLYGONOID))
+
+/* IS_HIGHEST_TYPE()
+ * These types are the most general in each of the type categories.
+ * Since timespan and datetime overload so many functions, let's
+ *  give datetime the preference.
+ * Since text is a generic string type let's leave it out too.
+ */
+#define IS_HIGHEST_TYPE(t) \
+		  (((t) == FLOAT8OID) \
+		|| ((t) == DATETIMEOID) \
+		|| ((t) == TIMESPANOID))
+
+
+extern bool IsPreferredType(CATEGORY category, Oid type);
+extern Oid PreferredType(CATEGORY category, Oid type);
+extern CATEGORY TypeCategory(Oid type);
+
+extern bool can_coerce_type(int nargs, Oid *input_typeids, Oid *func_typeids);
+extern Node *coerce_type(ParseState *pstate, Node *node, Oid inputTypeId, Oid targetTypeId);
+
+#endif							/* PARSE_COERCE_H */

src/include/parser/parse_func.h

@@ -6,7 +6,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: parse_func.h,v 1.8 1998/02/26 04:42:45 momjian Exp $
+ * $Id: parse_func.h,v 1.9 1998/05/09 23:31:34 thomas Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -49,6 +49,6 @@ extern Node *
 ParseFuncOrColumn(ParseState *pstate, char *funcname, List *fargs,
 				  int *curr_resno, int precedence);
 
-extern void func_error(char *caller, char *funcname, int nargs, Oid *argtypes);
+extern void func_error(char *caller, char *funcname, int nargs, Oid *argtypes, char *msg);
 
 #endif							/* PARSE_FUNC_H */