Change ln(), log(), power(), and sqrt() to emit the correct SQLSTATE

error codes for certain error conditions, as specified by SQL2003.

Author: Neil Conway

doc/src/sgml/errcodes.sgml

@@ -1,4 +1,4 @@
-<!-- $PostgreSQL: pgsql/doc/src/sgml/errcodes.sgml,v 1.5 2004/05/14 21:42:27 neilc Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/errcodes.sgml,v 1.6 2004/05/16 23:18:52 neilc Exp $ -->
 
 <appendix id="errcodes-appendix">
  <title><productname>PostgreSQL</productname> Error Codes</title>
@@ -310,6 +310,16 @@
 <entry>INTERVAL FIELD OVERFLOW</entry>
 </row>
 
+<row>
+<entry><literal>2201E</literal></entry>
+<entry>INVALID ARGUMENT FOR LOGARITHM</entry>
+</row>
+
+<row>
+<entry><literal>2201F</literal></entry>
+<entry>INVALID ARGUMENT FOR POWER FUNCTION</entry>
+</row>
+
 <row>
 <entry><literal>2201G</literal></entry>
 <entry>INVALID ARGUMENT FOR WIDTH BUCKET FUNCTION</entry>

src/backend/utils/adt/float.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/adt/float.c,v 1.104 2004/05/07 00:24:58 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/adt/float.c,v 1.105 2004/05/16 23:18:55 neilc Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1415,7 +1415,7 @@ dsqrt(PG_FUNCTION_ARGS)
 
 	if (arg1 < 0)
 		ereport(ERROR,
-				(errcode(ERRCODE_FLOATING_POINT_EXCEPTION),
+				(errcode(ERRCODE_INVALID_ARGUMENT_FOR_POWER_FUNCTION),
 				 errmsg("cannot take square root of a negative number")));
 
 	result = sqrt(arg1);
@@ -1449,6 +1449,16 @@ dpow(PG_FUNCTION_ARGS)
 	float8		arg2 = PG_GETARG_FLOAT8(1);
 	float8		result;
 
+	/*
+	 * The SQL spec requires that we emit a particular SQLSTATE error
+	 * code for certain error conditions.
+	 */
+	if ((arg1 == 0 && arg2 < 0) ||
+		(arg1 < 0 && floor(arg2) != arg2))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_ARGUMENT_FOR_POWER_FUNCTION),
+				 errmsg("invalid argument for power function")));
+
 	/*
 	 * We must check both for errno getting set and for a NaN result, in
 	 * order to deal with the vagaries of different platforms...
@@ -1501,22 +1511,24 @@ dexp(PG_FUNCTION_ARGS)
 
 /*
  *		dlog1			- returns the natural logarithm of arg1
- *						  ("dlog" is already a logging routine...)
  */
 Datum
 dlog1(PG_FUNCTION_ARGS)
 {
 	float8		arg1 = PG_GETARG_FLOAT8(0);
 	float8		result;
 
+	/*
+	 * Emit particular SQLSTATE error codes for ln(). This is required
+	 * by the SQL standard.
+	 */
 	if (arg1 == 0.0)
 		ereport(ERROR,
-				(errcode(ERRCODE_FLOATING_POINT_EXCEPTION),
+				(errcode(ERRCODE_INVALID_ARGUMENT_FOR_LOG),
 				 errmsg("cannot take logarithm of zero")));
-
 	if (arg1 < 0)
 		ereport(ERROR,
-				(errcode(ERRCODE_FLOATING_POINT_EXCEPTION),
+				(errcode(ERRCODE_INVALID_ARGUMENT_FOR_LOG),
 				 errmsg("cannot take logarithm of a negative number")));
 
 	result = log(arg1);
@@ -1535,14 +1547,19 @@ dlog10(PG_FUNCTION_ARGS)
 	float8		arg1 = PG_GETARG_FLOAT8(0);
 	float8		result;
 
+	/*
+	 * Emit particular SQLSTATE error codes for log(). The SQL spec
+	 * doesn't define log(), but it does define ln(), so it makes
+	 * sense to emit the same error code for an analogous error
+	 * condition.
+	 */
 	if (arg1 == 0.0)
 		ereport(ERROR,
-				(errcode(ERRCODE_FLOATING_POINT_EXCEPTION),
+				(errcode(ERRCODE_INVALID_ARGUMENT_FOR_LOG),
 				 errmsg("cannot take logarithm of zero")));
-
 	if (arg1 < 0)
 		ereport(ERROR,
-				(errcode(ERRCODE_FLOATING_POINT_EXCEPTION),
+				(errcode(ERRCODE_INVALID_ARGUMENT_FOR_LOG),
 				 errmsg("cannot take logarithm of a negative number")));
 
 	result = log10(arg1);

src/backend/utils/adt/numeric.c

@@ -14,7 +14,7 @@
  * Copyright (c) 1998-2003, PostgreSQL Global Development Group
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/adt/numeric.c,v 1.74 2004/05/14 21:42:28 neilc Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/adt/numeric.c,v 1.75 2004/05/16 23:18:55 neilc Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1668,6 +1668,7 @@ numeric_power(PG_FUNCTION_ARGS)
 	Numeric		res;
 	NumericVar	arg1;
 	NumericVar	arg2;
+	NumericVar	arg2_trunc;
 	NumericVar	result;
 
 	/*
@@ -1681,10 +1682,26 @@ numeric_power(PG_FUNCTION_ARGS)
 	 */
 	init_var(&arg1);
 	init_var(&arg2);
+	init_var(&arg2_trunc);
 	init_var(&result);
 
 	set_var_from_num(num1, &arg1);
 	set_var_from_num(num2, &arg2);
+	set_var_from_var(&arg2, &arg2_trunc);
+
+	trunc_var(&arg2_trunc, 0);
+
+	/*
+	 * Return special SQLSTATE error codes for a few conditions
+	 * mandated by the standard.
+	 */
+	if ((cmp_var(&arg1, &const_zero) == 0 &&
+		 cmp_var(&arg2, &const_zero) < 0) ||
+		(cmp_var(&arg1, &const_zero) < 0 &&
+		 cmp_var(&arg2, &arg2_trunc) != 0))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_ARGUMENT_FOR_POWER_FUNCTION),
+				 errmsg("invalid argument for power function")));
 
 	/*
 	 * Call power_var() to compute and return the result; note it handles
@@ -1696,6 +1713,7 @@ numeric_power(PG_FUNCTION_ARGS)
 
 	free_var(&result);
 	free_var(&arg2);
+	free_var(&arg2_trunc);
 	free_var(&arg1);
 
 	PG_RETURN_NUMERIC(res);
@@ -4408,10 +4426,16 @@ ln_var(NumericVar *arg, NumericVar *result, int rscale)
 	NumericVar	elem;
 	NumericVar	fact;
 	int			local_rscale;
+	int			cmp;
 
-	if (cmp_var(arg, &const_zero) <= 0)
+	cmp = cmp_var(arg, &const_zero);
+	if (cmp == 0)
 		ereport(ERROR,
-				(errcode(ERRCODE_FLOATING_POINT_EXCEPTION),
+				(errcode(ERRCODE_INVALID_ARGUMENT_FOR_LOG),
+				 errmsg("cannot take logarithm of zero")));
+	else if (cmp < 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_ARGUMENT_FOR_LOG),
 				 errmsg("cannot take logarithm of a negative number")));
 
 	local_rscale = rscale + 8;

src/include/utils/errcodes.h

@@ -11,7 +11,7 @@
  *
  * Copyright (c) 2003, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/include/utils/errcodes.h,v 1.10 2004/05/14 21:42:30 neilc Exp $
+ * $PostgreSQL: pgsql/src/include/utils/errcodes.h,v 1.11 2004/05/16 23:18:55 neilc Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -116,7 +116,9 @@
 #define ERRCODE_ESCAPE_CHARACTER_CONFLICT	MAKE_SQLSTATE('2','2', '0','0','B')
 #define ERRCODE_INDICATOR_OVERFLOW			MAKE_SQLSTATE('2','2', '0','2','2')
 #define ERRCODE_INTERVAL_FIELD_OVERFLOW		MAKE_SQLSTATE('2','2', '0','1','5')
-#define ERRCODE_INVALID_ARGUMENT_FOR_WIDTH_BUCKET_FUNCTION		MAKE_SQLSTATE('2','2', '0', '1', 'G')
+#define ERRCODE_INVALID_ARGUMENT_FOR_LOG	MAKE_SQLSTATE('2','2', '0','1','E')
+#define ERRCODE_INVALID_ARGUMENT_FOR_POWER_FUNCTION	MAKE_SQLSTATE('2','2', '0', '1', 'F')
+#define ERRCODE_INVALID_ARGUMENT_FOR_WIDTH_BUCKET_FUNCTION	MAKE_SQLSTATE('2','2', '0', '1', 'G')
 #define ERRCODE_INVALID_CHARACTER_VALUE_FOR_CAST		MAKE_SQLSTATE('2','2', '0','1','8')
 #define ERRCODE_INVALID_DATETIME_FORMAT		MAKE_SQLSTATE('2','2', '0','0','7')
 #define ERRCODE_INVALID_ESCAPE_CHARACTER	MAKE_SQLSTATE('2','2', '0','1','9')