cpp seems not to include # line "file" output for empty files

[Horst von Brand]

Daniel Berlin <dberlin@redhat.com> said:

[...]

> If you want dependency info from cpp, use the switches to tell it to
> give you dependency info.

That may mean hacking up a bunch of unreadable Makefiles...

> Also, if the file generates no output, then a.c really wasn't dependent
> on it.

Wrong. In the example the a.h file #defines something, which doesn't
generate output but can influence the result of compiling a.c.
-- 
Horst von Brand                             vonbrand@sleipnir.valparaiso.cl
Casilla 9G, Vin~a del Mar, Chile                               +56 32 672616