How to define global preprocessors please?

[shadowsocks]

My language is C++ and I am using version 11.0.6 .
I want to define preprocessors so that I can use #ifdef without typing " #define XXX " too many times in the code . I see that I can do that by right-clicking a project , and then enter settings->compiler->preprocessors. However I have to do that for every new project , so I wonders is it possible to set the preprocessors for a whole IDE/Compiler/workspace ? Thanks.