Integer Operation Without Overflow Check

Question

Hi I just ran a static code analysis on my code and I keep getting the error

"Integer Operation Without Overflow Check"

Can someone help me resolve this or tell me what it means exactly. I have already tried to using the check keywords to fix this but it still came up when I ran the code.

List<String> emailList = new List<string>();

if (tbRecipients.Text.Contains(','))
{
    string[] splits = tbRecipients.Text.Split(',');

    for (int i = 0; i < splits.Length; i++)
    {
        if (splits[i].Contains(';'))
        {
            emailList.AddRange(splits[i].Split(';').ToList());
        }
        else
        {
            emailList.Add(splits[i]);
        }
    }
}

ASPX

<asp:TextBox ID="tbRecipients"  runat="server"  ></asp:TextBox>

What tool are you using to make the analysis? Does it points to a line in particular or just the whole block of code? — Luiso, Jun 08 '16 at 19:11
VCG and yes it points to this line for (int i = 0; i < splits.Length; i++) — Jordan Ardakanian, Jun 08 '16 at 19:16

Luiso · Answer 1 · 2016-06-08T19:40:55.150

The message you get says that you could get an "overflow" on an int, that's because ints in C# are 32 bit so that you can only store in it numbers lower than 2^31. So VCG tell you that while doing several i++ you could end up with an i = 2^31 which would overflow your int and yield unexpected code behavior.

This could only happen in your code in the case that splitted.Length == int.MaxValue since splitted is an array and the Length property is int, so when you get i == int.MaxLength the loop will evaluate i == splitted.Length and will go to i++ which would overflow.

However your loop says i < splitted.Length so that i == splitted.Length won't happen.

Bottom line: I think VCG has spotted a suspicious line, but there is nothing to worry about.
Hope this helps, happy coding.

score 2 · Answer 2 · answered Jun 08 '16 at 18:59

I have already tried to using the check keywords to fix this

The first step would be to understand the message. Making random code changes it not a good way to deal with possible bugs that are reported to you.

Here, there is no possible integer overflow. Hard to say more without details about the tool.

Integer Operation Without Overflow Check

2 Answers2