2.2.1  Fixed Source Form Conditional Compilation Sentinels

The following conditional compilation sentinels are recognized in fixed form source files:  

 
!$ | *$ | c$
  

To enable conditional compilation, a line with a conditional compilation sentinel must satisfy the following criteria:

• The sentinel must start in column 1 and appear as a single word with no intervening white space;
• After the sentinel is replaced with two spaces, initial lines must have a space or zero in column 6 and only white space and numbers in columns 1 through 5;
• After the sentinel is replaced with two spaces, continuation lines must have a character other than a space or zero in column 6 and only white space in columns 1 through 5.

If these criteria are met, the sentinel is replaced by two spaces. If these criteria are not met, the line is left unchanged.

Note – In the following example, the two forms for specifying conditional compilation in fixed source form are equivalent (the first line represents the position of the first 9 columns):  

 
c23456789 
!$ 10 iam = omp_get_thread_num() + 
!$   &          index 
 
#ifdef _OPENMP 
   10 iam = omp_get_thread_num() + 
     &            index 
#endif