postgres.git / summary / log / commit / refs

commit    24aad03e98a7e38614100457defdedf75c473bc4
Author:   Tom Lane <tgl@sss.pgh.pa.us>
Date:     Fri Mar 11 23:19:07 2011 +0000

    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 | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/src/backend/utils/adt/int8.c b/src/backend/utils/adt/int8.c
index 3391769cd43..88bf703df67 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;
 
@@ -645,9 +649,14 @@ 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);
@@ -821,9 +830,13 @@ 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;
 
@@ -915,10 +928,16 @@ int48div(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((int64) arg1 / arg2);
 }
 


[parent: e476eedd0c06]