A.2.94.1 Examples

The following command undefines the predefined symbol __sun. Preprocessor statements in foo.cc such as #ifdef(__sun) will sense that the symbol is undefined.

example% CC -U__sun foo.cc

Interactions

You can specify multiple -U options on the command line.

All -U options are processed after any -D options that are present. That is, if the same name is specified for both -D and -U on the command line, name is undefined, regardless of the order the options appear.

See also

-D