How to build Emacs with debugging information?

[Oleh]

Hi all,

Sorry if I'm asking obvious things, I'm not too experienced with C.

I wanted to step through `scan_lists' from syntax.c to understand why
and how "<" and ">" are matched in `c++-mode'. For example, they won't
be matched here, calling `forward-list':

    #include <vector>

but will be matched here:

    vector<int> foo;

Anyway, stepping with gdb, inside another Emacs instance, I see that
many values are "<optimized out>", e.g.

    (gdb) p found
    $1 = <optimized out>

Normally I would pass "-g -O0" flags to gcc to solve this for the
C/C++ programs that I write. How can I do the equivalent thing for
Emacs? Is there a way to have both the "debug" and "release"
configurations for the Emacs executable?

regards,
Oleh