UNDEFINE

Pragma equivalent

None.

Purpose

Undefines preprocessor macro names.

Syntax


             .-,----.      
             V      |      
>>-UNDEF--(----name-+--)---------------------------------------><

Defaults

Not applicable.

Parameters

name: Specifies a preprocessor macro name.

Usage

UNDEFINE(name) removes any value that name may have and makes its value undefined. For example, if you set OS2 to 1 with DEF(OS2=1), you can use the UNDEF(OS2) option to remove that value.

In the z/OS® UNIX System Services environment, you can unset variables by specifying -U when using the c89, cc, or c++ commands.

Note: c89 preprocesses -D and -U flags before passing them to the compiler. xlc just passes -D and -U to the compiler, which interprets them as DEFINE and UNDEFINE. For more information, see c89 — Compiler invocation using host environment variables or xlc — Compiler invocation using a customizable configuration file.

Predefined macros