C preprocessor handling

[sh1boot]

I notice the default is to ignore preprocessor lines, and I guess that's because their normally-zero indent would reset the whole system to zero every time one occurred.

I suppose the logical indentation of preprocessor depends on interpreting the lines (stepping up and down with #if and #endif) and keeping separate counters and extending all the way to the start of the file because there's no fast-out on the left margin.

Is such a thing feasible?