Our website uses cookies to enhance your browsing experience.
Accept
to the top
close form

Fill out the form in 2 simple steps below:

Your contact information:

Step 1
Congratulations! This is your promo code!

Desired license type:

Step 2
Team license
Enterprise license
** By clicking this button you agree to our Privacy Policy statement
close form
Request our prices
New License
License Renewal
--Select currency--
USD
EUR
* By clicking this button you agree to our Privacy Policy statement

close form
Free PVS‑Studio license for Microsoft MVP specialists
* By clicking this button you agree to our Privacy Policy statement

close form
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

close form
I am interested to try it on the platforms:
* By clicking this button you agree to our Privacy Policy statement

close form
check circle
Message submitted.

Your message has been sent. We will email you at


If you do not see the email in your inbox, please check if it is filtered to one of the following folders:

  • Promotion
  • Updates
  • Spam

>
>
>
V695. Range intersections are possible …
menu mobile close menu
Analyzer diagnostics
General Analysis (C++)
General Analysis (C#)
General Analysis (Java)
Micro-Optimizations (C++)
Diagnosis of 64-bit errors (Viva64, C++)
Customer specific requests (C++)
MISRA errors
AUTOSAR errors
OWASP errors (C++)
OWASP errors (C#)
Problems related to code analyzer
Additional information
toggle menu Contents

V695. Range intersections are possible within conditional expressions.

May 29 2014

The analyzer has detected a potential error in a condition. The program must perform different actions depending on which range of values a certain variable meets.

For this purpose, the following construct is used in the code:

if ( MIN_A < X && X < MAX_A ) {
  ....
} else if ( MIN_B < X && X < MAX_B ) {
  ....
}

The analyzer generates the warning when the ranges checked in conditions overlap. For example:

if ( 0 <= X && X < 10)
  FooA();
else if ( 10 <= X && X < 20)
  FooB();
else if ( 20 <= X && X < 300)
  FooC();
else if ( 30 <= X && X < 40)
  FooD();

The code contains a typo. The programmer's fingers faltered at some moment and he wrote "20 <= X && X < 300" instead of "20 <= X && X < 30" by mistake. If the X variable stores, for example, the value 35, it will be the function FooC() that will be called instead of FooD().

The fixed code:

if ( 0 <= X && X < 10)
  FooA();
else if ( 10 <= X && X < 20)
  FooB();
else if ( 20 <= X && X < 30)
  FooC();
else if ( 30 <= X && X < 40)
  FooD();

Here is another example:

const int nv_ab = 5;
const int nv_bc = 10;
const int nv_re = 15;
const int nv_we = 20;
const int nv_tw = 25;
const int nv_ww = 30;
....
if (n < nv_ab) { AB(); }
else if (n < nv_bc) { BC(); }
else if (n < nv_re) { RE(); }
else if (n < nv_tw) { TW(); }   // <=
else if (n < nv_we) { WE(); }   // <=
else if (n < nv_ww) { WW(); }

Depending on the value of the 'n' variable, different actions are performed. Poor variable naming may confuse a programmer - and so it did in this example. The 'n' variable should have been compared to 'nv_we' first and only then to 'nv_tw'.

To make the mistake clear, let's substitute the values of the constants into the code:

if (n < 5) { AB(); }
else if (n < 10) { BC(); }
else if (n < 15) { RE(); }
else if (n < 25) { TW(); }
else if (n < 20) { WE(); } // Condition is always false
else if (n < 30) { WW(); }

The fixed code:

if (n < nv_ab) { AB(); }
else if (n < nv_bc) { BC(); }
else if (n < nv_re) { RE(); }
else if (n < nv_we) { WE(); }    // <=
else if (n < nv_tw) { TW(); }    // <=
else if (n < nv_ww) { WW(); }

This diagnostic is classified as:

You can look at examples of errors detected by the V695 diagnostic.