[previous] 4394 [next] A composite expression of 'essentially unsigned' type (%1s) is being cast to a different type category, '%2s'.
Arithmetic type - Composite expressions

This message is issued whenever a composite expression of essentially unsigned type has been cast to a different essential type category.

It is a common misconception among programmers that the type in which the arithmetic operation is evaluated is influenced by the cast-to type. Instead, the type of the expression is determined solely from the type of its operands after any integral promotion. Therefore, wraparound may occur, which could be avoided if operands were cast instead.

For example: 


/*PRQA S 1-9999 ++*/
/*PRQA S 4394 --*/

void foo (int b);

int f4394 (unsigned short a)
{
  foo ((int) (a + 1u));    /* 4394 */

  return ((int) (a * 2u)); /* 4394 */
}

QA·C Source Code Analyser 8.1.2
© 2013 Programming Research.
www.programmingresearch.com 		Personality Groups | Glossary | Message Index Contents