Before preprocessing, a null statement shall only occur on a line by itself; it may be followed by a comment provided that the first character following the null statement is a white-space character

Null statements should not normally be included deliberately, but where they are used, they shall appear on a line by themselves. White-space characters may precede the null statement to preserve indentation. If a comment follows the null statement, then at least one white-space character shall separate the null statement from the comment. The use of a white-space character to separate the null statement from any following comment is required on the grounds that it provides an important visual cue to reviewers. Following this rule enables a static checking tool to warn of null statements appearing on a line with other text, which would normally indicate a programming error.

Noncompliant Code Example

while ( ( port & 0x80 ) == 0 )
{
  /* wait for pin */ ; // Noncompliant, comment before ;
  ;// wait for pin - Noncompliant, no white-space char after ;
}

Compliant Solution

while ( ( port & 0x80 ) == 0 )
{
  ; // wait for pin - Compliant
}

See Also

• MISRA C:2004, 14.3
• MISRA C++:2008, 6-2-3