ASML C Coding Standard

Rule: 6.8.4.b

Synopsis:	The condition (or guard) of a selective alternative shall be a logical operator, an equality operator or a relational expression (and not be an assignment). Exception is made for boolean type. For boolean type no relational expression is required.
Language:	C
Severity Level:	6
Category:	Statement and Blocks

Description:

Justification

Example 1

if (i = a) /* WRONG: assignment as well as a test */
{                                       
   /* Any statement */
}

Example 2

if (i) /* WRONG */
{
   /* Any statement */
}

Example 3

if (i == 1) /* RIGHT: equality operator */
{
   /* Any statement */
}

Example 4

if (fp = fopen("TMP", "r")) /* WRONG */
{
   /* Any statement */
}

Example 5

if (!(fp = fopen("TMP", "r"))) /* WRONG */
{
   /* Any statement */
}

Example 6

fp = fopen("TMP", "r");

if (fp != NULL) /* RIGHT */
{
   /* Any statement */
}

Example 7

bool doorclosed(void);

if (doorclosed() == true) /* WRONG */
{
   /* Any statement */
}

Example 8

bool doorclosed(void);

if (doorclosed()) /* RIGHT: by exception */
{
   /* Any statement */
}