Why is FxCop warning about an overflow (CA2233) in this C# code?

Posted by matt on Stack Overflow See other posts from Stack Overflow or by matt
Published on 2010-04-15T01:34:15Z Indexed on 2010/04/15 1:43 UTC
Read the original article Hit count: 421

Filed under:

fxcop

|

c#

|

overflow

I have the following function to get an int from a high-byte and a low-byte:

public static int FromBytes(byte high, byte low)
{
    return high * (byte.MaxValue + 1) + low;
}

When I analyze the assembly with FxCop, I get the following critical warning:

CA2233: OperationsShouldNotOverflow
Arithmetic operations should not be done without first validating the operands to prevent overflow.

I can't see how this could possibly overflow, so I am just assuming FxCop is being overzealous.
Am I missing something? And what steps could be taken to correct what I have (or at least make the FxCop warning go away!)?

© Stack Overflow or respective owner

Related posts about fxcop

Exclude complete namespace from FxCop code analysis?

as seen on Stack Overflow - Search for 'Stack Overflow'
Is it possible to exclude a complete namespace from all FxCop analysis while still analyzing the rest of the assembly using the SuppressMessageAttribute? In my current case, I have a bunch of classes generated by LINQ to SQL which cause a lot of FxCop issues, and obviously, I will not modify all… >>> More
Mark assembly App_licenses.dll with AssemblyVersion (FxCop CA1016 rule)

as seen on Stack Overflow - Search for 'Stack Overflow'
Hello everyone, I'm trying to fulfil FxCop's rules in my web site. Since I use some Infragistics controls I have a licenses.licx file that turns into a "app_licenses.dll" assembly after publication. The problem is that this app_licenses.dll assembly does not comply with rule CA1016 (MarkAssembliesWithAssemblyVersion)… >>> More
Creating a readable FxCop report

as seen on Stack Overflow - Search for 'Stack Overflow'
Is there a good tool that can convert the XML output of FxCop into something that can be put into a Word document? I'd prefer not to write an XML-FO XSLT transform, maybe someone did something like that already. >>> More
Error: Cannot find .net assembly during FxCop analysis

as seen on Stack Overflow - Search for 'Stack Overflow'
I'm running FxCop from MSBuild and during the analysis it throws an error stating that it could not find the System.XML assembly and that I need to specify the location using the /directory parameter, which I then did but it didn't work. Any idea what I should do? I am running it on projects built… >>> More
Using FxCop to analyse only the latest changes

as seen on Stack Overflow - Search for 'Stack Overflow'
I am trying to get FxCop to work in a way that it analyses only the incremental changes in the exe/dll that it analyses and not the entire thing as it has anlaysed that part already.... any thoughts how one could achieve this?? ... thanks in advance... Regards, ASV... >>> More

Related posts about c#

.NET WebRequest.PreAuthenticate not quite what it sounds like

as seen on West-Wind - Search for 'West-Wind'
I’ve run into the problem a few times now: How to pre-authenticate .NET WebRequest calls doing an HTTP call to the server – essentially send authentication credentials on the very first request instead of waiting for a server challenge first? At first glance this sound like it should be easy:… >>> More
HttpWebRequest and Ignoring SSL Certificate Errors

as seen on West-Wind - Search for 'West-Wind'
Man I can't believe this. I'm still mucking around with OFX servers and it drives me absolutely crazy how some these servers are just so unbelievably misconfigured. I've recently hit three different 3 major brokerages which fail HTTP validation with bad or corrupt certificates at least according to… >>> More
Dynamic Type to do away with Reflection

as seen on West-Wind - Search for 'West-Wind'
The dynamic type in C# 4.0 is a welcome addition to the language. One thing I’ve been doing a lot with it is to remove explicit Reflection code that’s often necessary when you ‘dynamically’ need to walk and object hierarchy. In the past I’ve had a number of ReflectionUtils that used string based expressions… >>> More
The dynamic Type in C# Simplifies COM Member Access from Visual FoxPro

as seen on West-Wind - Search for 'West-Wind'
I’ve written quite a bit about Visual FoxPro interoperating with .NET in the past both for ASP.NET interacting with Visual FoxPro COM objects as well as Visual FoxPro calling into .NET code via COM Interop. COM Interop with Visual FoxPro has a number of problems but one of them at least got a lot… >>> More
Finding a Relative Path in .NET

as seen on West-Wind - Search for 'West-Wind'
Here’s a nice and simple path utility that I’ve needed in a number of applications: I need to find a relative path based on a base path. So if I’m working in a folder called c:\temp\templates\ and I want to find a relative path for c:\temp\templates\subdir\test.txt I want to receive back subdir\test… >>> More