To get a trial key
fill out the form below
Team License (standard version)
Enterprise License (extended version)
* By clicking this button you agree to our Privacy Policy statement

** This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Request our prices
New License
License Renewal
--Select currency--
USD
EUR
GBP
RUB
* By clicking this button you agree to our Privacy Policy statement

** This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
To get the licence for your open-source project, please fill out this form
* By clicking this button you agree to our Privacy Policy statement

** This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
To get the licence for your open-source project, please fill out this form
* By clicking this button you agree to our Privacy Policy statement

** This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
I am interested to try it on the platforms:
* By clicking this button you agree to our Privacy Policy statement

** This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Message submitted.

Your message has been sent. We will email you at


If you haven't received our response, please do the following:
check your Spam/Junk folder and click the "Not Spam" button for our message.
This way, you won't miss messages from our team in the future.

>
>
>
V651. An odd operation of the 'sizeof(X…
Analyzer Diagnostics
General Analysis (C++)
General Analysis (C#)
General Analysis (Java)
Diagnosis of micro-optimizations (C++)
Diagnosis of 64-bit errors (Viva64, C++)
MISRA errors
AUTOSAR errors
Additional information
Contents

V651. An odd operation of the 'sizeof(X)/sizeof(T)' kind is performed, where 'X' is of the 'class' type.

Nov 09 2012

The analyzer has detected a potential error in an expression of the 'sizeof(X)/sizeof(X[0])' kind. The strange thing is that the 'X' object is a class instance.

The 'sizeof(X)/sizeof(X[0]) ' is usually used to calculate the number of items in the 'X' array. The error might occur during careless code refactoring. The 'X' variable was an ordinary array at first and was then replaced with a container class, while calculation of the items number remained the same.

Consider an example of incorrect code:

#define countof( x ) (sizeof(x)/sizeof(x[0]))
Container<int, 4> arr;
for( int i = 0; i < countof(arr); i++ )
{ .... }

The programmer expected the code to calculate the number of the items of the 'arr' variable. But the resulting value is the class size divided by the size of the 'int'- variable. Most likely, this value is not in any way related to the number of data items being stored in the container.

This is the fixed code:

const size_t count = 4;
Container<int, count> arr;
for( int i = 0; i < arr.size(); i++ )
{ .... }

This diagnostic is classified as:

This website uses cookies and other technology to provide you a more personalized experience. By continuing the view of our web-pages you accept the terms of using these files. If you don't want your personal data to be processed, please, leave this site.
Learn More →
Accept