According to the Open Source Definition of the OSI it's not:

> The program must include source code [...] The source code must be the preferred form in which a programmer would modify the program. Deliberately obfuscated source code is not allowed. Intermediate forms such as the output of a preprocessor [...] are not allowed.

The popular licenses for which this is a design concern are careful to define source code to mean "preferred form of the work for making modifications" or similar.