How to run the cpp(preprocessor) g++ tests?

[Andres Tiraboschi]

Hi, I've been working a bit with the gcc preprocessor but don't know
exactly how to run just the cpp tests for g++(the tests located in the
gccSource/gcc/testsuite/g++.dg/cpp/) without running all the
testsuite.
I couldn't find anything about it in the documentation.

pd: I'm working with gcc-5.2.0.

Best regards,
Andrés