Customizing C/C++ Default Compiler Options

CUSTOMIZING DEFAULT OPTIONS FOR C/C++ COMPILER

This is for customers who want to change the default options for the C/C++ Compilers shipped with z/OS®. Usermods CCNHOPT in CBC.SCCNJCL(CCNJHOPT), CCNHOPX within CBC.SCCNJCL(CCNJHOPX), CCNJOPT within CBC.SCCNJCL, and CCNJOPX within CBC.SCCNJCL contain misleading comments as in the following example:

CCNEO0HC CSECT                                                        
CCNEO0HC RMODE ANY                                                    
CCNEO0HC AMODE ANY                                                    
* YOU CAN EITHER CODE THE LENGTH IN THE FULLWORD BELOW, OR            
* NULL TERMINATE THE STRING WITH AN X'00' AS SHOWN                    
       DC    F'0'                                                      
       DC    C'HALT(16) '                                              
       DC    C'SEARCH(/USR/INCLUDE/) '                                
       DC    X'00'  (NULL-TERMINATE THE STRING)                
       END

The comments are incorrect. The compiler does not use the DC F'0' as the length of the option string. Do not remove the DC F'0' as it is required for the compiler to process the options correctly.The DC X'00' at the end of the options string is also required.

Options can be added by inserting a DC C'option ' anywhere between the DC F'0' and the DC X'00'. Note that the space after the option is required as a separator. The C/C++ Users Guide (SC09-4767) contains a detailed description of the options available. Members CBCHJOPT, CBCHJOPX, within CBC.SCBCJCL also contain the same comments and in addition do not have a space after the HALT option:
Wrong: DC  C'HALT(16)'

Right:  DC  C'HALT(16) '

See the related information to locate the online manuals and program directories for your release of the z/OS or OS390.