Sorry, if this question doesn't make any sense but It just came to my mind, I was looking for a solution on this from quite long time but in the end I thought better to check with experts. :)

Below is a scenario:

1. Suppose In myProject.pro file, I have 
 PATH = /home/local/Projects/
for which I created a QT DEFINE using below:
 DEFINES += PATH =\\"$${PATH}\\"
2. Now, I can use this "PATH" any where in my Project which is based on CPP file. This if perfectly fine.
3. Now, depending upon the input from user, I want to change this "PATH"
say, PATH can be:
 PATH = /home/local/Projects/TEST1/

```
PATH = /home/local/Projects/TEST2/

        and revert to

PATH = /home/local/Projects/

```

So, that wherever I am using this "PATH" in my project will be changed automatically. 

I know this is done at compile time. But came a thought. So wanted to get feedbacks from experts.