Program development questions

[Caj Zell]

Hi, 

I want to ask three (probably simple) questions in connections with c
programming in emacs. (I have tried to find answers in faq's, etc.)

1. I have a Makefile in a top directory and under it other
directories, where one is a source directory in which I am often
editing files. When I want to compile the software, I want to run the
mentioned Makefile in the above directory from emacs, but the "current
directory" has no Makefile so I get "no target with so-and-so name".
Is there a simple way of letting emacs know it should compile like
from the above directory.

2. Running etags and then M-., I come to the definition of a function,
variable, etc. But, if I want to find several other places where the
specific function is called, and not just the definition, how can I do
that?

3. Is there a general consensus as to which package to use for code
browsing under emacs? Is "ecb" the most used?

Caj Zell