macro macro-list
Where, macro-list =macro_name_1 macro_name_2=value_2...macro_name_n
Use the macro statement to specify #defines for the preprocessing of source code. You can specify multiple macros separated by a space. if required, you can also assign values to those macros.
Note: It is not mandatory that all the macros listed must have a value.
Each macro specified is passed to the complier using the option -d for preprocessing the C++ source code in your project.