postgres.git / summary / log / commit / refs

commit    0e68e1087c8ad0d1a05fa3bcf758887cb5123ca9
Author:   Tom Lane <tgl@sss.pgh.pa.us>
Date:     Fri Mar 11 23:19:03 2011 +0000
First released in: 9.1.0, 8.2.21, 8.3.15, 8.4.8, 9.0.4

    Put in some more safeguards against executing a division-by-zero.
    
    Add dummy returns before every potential division-by-zero in int8.c,
    because apparently further "improvements" in gcc's optimizer have
    enabled it to break functions that weren't broken before.
    
    Aurelien Jarno, via Martin Pitt


 src/backend/utils/adt/int8.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/src/backend/utils/adt/int8.c b/src/backend/utils/adt/int8.c
index d8ee8c6c982..5e8cc030137 100644
--- a/src/backend/utils/adt/int8.c
+++ b/src/backend/utils/adt/int8.c
@@ -599,9 +599,13 @@ int8div(PG_FUNCTION_ARGS)
 	int64		result;
 
 	if (arg2 == 0)
+	{
 		ereport(ERROR,
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
+		/* ensure compiler realizes we mustn't reach the division (gcc bug) */
+		PG_RETURN_NULL();
+	}
 
 	result = arg1 / arg2;
 
@@ -646,9 +650,14 @@ int8mod(PG_FUNCTION_ARGS)
 	int64		arg2 = PG_GETARG_INT64(1);
 
 	if (arg2 == 0)
+	{
 		ereport(ERROR,
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
+		/* ensure compiler realizes we mustn't reach the division (gcc bug) */
+		PG_RETURN_NULL();
+	}
+
 	/* No overflow is possible */
 
 	PG_RETURN_INT64(arg1 % arg2);
@@ -824,9 +833,13 @@ int84div(PG_FUNCTION_ARGS)
 	int64		result;
 
 	if (arg2 == 0)
+	{
 		ereport(ERROR,
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
+		/* ensure compiler realizes we mustn't reach the division (gcc bug) */
+		PG_RETURN_NULL();
+	}
 
 	result = arg1 / arg2;
 
@@ -1008,9 +1021,13 @@ int82div(PG_FUNCTION_ARGS)
 	int64		result;
 
 	if (arg2 == 0)
+	{
 		ereport(ERROR,
 				(errcode(ERRCODE_DIVISION_BY_ZERO),
 				 errmsg("division by zero")));
+		/* ensure compiler realizes we mustn't reach the division (gcc bug) */
+		PG_RETURN_NULL();
+	}
 
 	result = arg1 / arg2;
 


[parent: 994940f2fb26]