Gcc preprocessor can rewrite source code?

[SunBurnt]

In my quest to find a way to patch an exec`s /path/to/it`s/dep./files someone suggested cpp.
This seems like it would work on almost all source files, providing the correct setup were found.
It would still be necessary to compile the packages, but if it works well enough then it`s worth it.

cpp could patch the execs dep. paths, or it could alter the exec so it would allow --prefix ... to do it.

I`m trying to nail down one or two methods that will fix most all packages, binary preferred, or source.